Patent application number | Description | Published |
20080206993 | Using Spectra to Determine Polishing Endpoints - Methods of determining a polishing endpoint are described using spectra obtained during a polishing sequence. In particular, techniques for using only desired spectra, faster searching methods and more robust rate determination methods are described. | 08-28-2008 |
20080239308 | HIGH THROUGHPUT MEASUREMENT SYSTEM - A substrate processing system includes a processing module to process a substrate, a factory interface module configured to accommodate at least one cassette for holding the substrate, a spectrographic monitoring system positioned in or adjoining the factory interface module, and a substrate handler to transfer the substrate between the at least one cassette, the spectrographic monitoring system and the processing module. | 10-02-2008 |
20080243433 | METHODS AND APPARATUS FOR GENERATING A LIBRARY OF SPECTRA - A method of generating a library from a reference substrate for use in processing product wafers is described. The method includes measuring substrate characteristics at a plurality of well-defined points of a reference substrate, measuring spectra at plurality of measurement points of the reference substrate, there being more measurement points than well-defined points, and associating measured spectra with measured substrate characteristics. | 10-02-2008 |
20090017726 | SPECTRA BASED ENDPOINTING FOR CHEMICAL MECHANICAL POLISHING - Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting two or more reference spectra. Each reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectra is selected for particular spectra-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectra-based endpoint logic. The method includes obtaining two or more current spectra. Each current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. | 01-15-2009 |
20090033942 | Determining Physical Property of Substrate - A method of determining a physical property of a substrate includes recording a first spectrum obtained from a substrate, the first spectrum being obtained during a polishing process that alters a physical property of the substrate. The method includes identifying, in a database, at least one of several previously recorded spectra that is similar to the recorded first spectrum. Each of the spectra in the database has a physical property value associated therewith. The method includes generating a signal indicating that a first value of the physical property is associated with the first spectrum, the first value being determined using the physical property value associated with the identified previously recorded spectrum in the database. A system for determining a physical property of a substrate includes a polishing machine, an endpoint determining module, and a database. | 02-05-2009 |
20090036026 | SUBSTRATE THICKNESS MEASURING DURING POLISHING - A computer program product that determines a polishing endpoint includes obtaining spectra from different zones on a substrate during different times in a polishing sequence, matches the spectra with indexes in a library and uses the indexes to determining a polishing rate for each of the different zones from the indexes. An adjusted polishing rate can be determined for one of the zones, which causes the substrate to have a desired profile when the polishing end time is reached. | 02-05-2009 |
20100035519 | REMOVABLE OPTICAL MONITORING SYSTEM FOR CHEMICAL MECHANICAL POLISHING - A polishing system includes a platen having a top surface to receive a polishing pad, a recess in the top surface, and a cavity inside the platen spaced from the recess, a carrier head to hold a surface of a substrate against the polishing pad on the platen, a monitoring module located in the cavity, the monitoring module including a light source and a detector, an optical head removably mounted in the recess in the top surface platen, and an optical fiber having a proximate end coupled to the monitoring module and a distal end held by the optical head holding the distal end of the optical fiber in a position to direct light through a window in the polishing pad to the surface of the substrate and receive reflected light from the surface of the substrate. | 02-11-2010 |
20100056023 | Adjusting Polishing Rates by Using Spectrographic Monitoring of a Substrate During Processing - A computer-implemented method includes receiving a sequence of current spectra of reflected light from a substrate; comparing each current spectrum from the sequence of current spectra to a plurality of reference spectra from a reference spectra library to generate a sequence of best-match reference spectra; determining a goodness of fit for the sequence of best-match reference spectra; and determining at least one of whether to adjust a polishing rate or an adjustment for the polishing rate, based on the goodness of fit. | 03-04-2010 |
20100075582 | POLISHING PAD ASSEMBLY WITH GLASS OR CRYSTALLINE WINDOW - Methods and apparatus for providing a chemical mechanical polishing pad. The pad includes a polishing layer having a top surface and a bottom surface. The pad includes an aperture having a first opening in the top surface and a second opening in the bottom surface. The top surface is a polishing surface. The pad includes a window that includes a first portion made of soft plastic and a crystalline or glass like second portion. The window is transparent to white light. The window is situated in the aperture so that the first portion plugs the aperture and the second portion is on a bottom side of the first portion, wherein the first portion acts a slurry-tight barrier. | 03-25-2010 |
20100103422 | GOODNESS OF FIT IN SPECTROGRAPHIC MONITORING OF A SUBSTRATE DURING PROCESSING - A sequence of current spectra is obtained with an in-situ optical monitoring system, and each current spectrum is compared to a plurality of reference spectra from a plurality of reference spectra libraries. The library that provides a best fit to the sequence of current spectra is determined, and a polishing endpoint is determined based on the sequence of current spectra and the library that provides a best fit to the sequence of current spectra. | 04-29-2010 |
20100105288 | MULTIPLE LIBRARIES FOR SPECTROGRAPHIC MONITORING OF ZONES OF A SUBSTRATE DURING PROCESSING - Methods, systems, and apparatus, including computer program products, for spectrographic monitoring of a substrate during chemical mechanical polishing are described. In one aspect, a computer-implemented method includes receiving a first sequence of current spectra of reflected light from a first zone of a substrate. A second sequence of current spectra of reflected light from a second zone of the substrate is received. Each current spectrum from the first sequence of current spectra is compared to a plurality of reference spectra from a first reference spectra library to generate a first sequence of best-match reference spectra. Each current spectrum from the second sequence of current spectra is compared to a plurality of reference spectra from a second reference spectra library to generate a second sequence of best-match reference spectra. The second reference spectra library is distinct from the first reference spectra library. | 04-29-2010 |
20100114532 | WEIGHTED SPECTROGRAPHIC MONITORING OF A SUBSTRATE DURING PROCESSING - A substrate having an outermost layer undergoing polishing and at least one underlying layer is irradiated with light. A sequence of current spectra is obtained with an in-situ optical monitoring system, a current spectrum from the sequence of current spectra being a spectrum of the light reflected from the substrate, wherein the current spectrum includes a range of wavelengths and, for all wavelengths in the range of wavelengths, a value corresponding to a wavelength. Further, a value of the current spectrum corresponding to a wavelength is modified with at least one value in a gain factor spectrum, wherein the gain factor spectrum includes a first range of wavelengths and, for all wavelengths in the first range of wavelengths, a value corresponding to a wavelength. The polishing of the outermost layer of the substrate is then changed based upon the modified value of the current spectrum. | 05-06-2010 |
20100124870 | Semi-Quantitative Thickness Determination - While a substrate is polished, it is also irradiated with light from a light source. A current spectrum of the light reflected from the surface of the substrate is measured. A selected peak, having a first parameter value, is identified in the current spectrum. A value of a second parameter associated with the first parameter is determined from a lookup table using a processor. Depending on the value of the second parameter, the polishing of the substrate is changed. An initial spectrum of light reflected from the substrate before the polishing of the substrate can be measured and a wavelength corresponding to a selected peak of the initial spectrum can be determined. | 05-20-2010 |
20100129939 | USING OPTICAL METROLOGY FOR WITHIN WAFER FEED FORWARD PROCESS CONTROL - A method of controlling the polishing of a substrate includes polishing a substrate on a first platen using a first set of parameters, obtaining first and second sequences of measured spectra from first and second regions of the substrate with an in-situ optical monitoring system, generating first and second sequences of values from the first and second sequences of measured spectra, fitting first and second linear functions to the first and second sequences of values, determining a difference between the first linear function and the second linear function, adjusting at least one parameter of a second set of parameters based on the difference, and polishing the substrate on a second platen using the adjusted parameter. | 05-27-2010 |
20100130100 | USING OPTICAL METROLOGY FOR WAFER TO WAFER FEED BACK PROCESS CONTROL - A method of controlling the polishing of a substrate includes polishing a substrate on a first platen using a first set of parameters, obtaining first and second sequences of measured spectra from first and second regions of the substrate with an in-situ optical monitoring system, generating first and second sequences of values from the first and second sequences of measured spectra, fitting first and second linear functions to the first and second sequences of values, determining a difference between the first linear function and the second linear function, adjusting at least one parameter of the first set of parameters based on the difference, and polishing the second substrate on the first platen using the adjusted parameter. | 05-27-2010 |
20100217430 | SPECTROGRAPHIC MONITORING OF A SUBSTRATE DURING PROCESSING USING INDEX VALUES - Methods, systems, and apparatus for spectrographic monitoring of a substrate during chemical mechanical polishing are described. In one aspect, a computer-implemented method includes storing a library having a plurality of reference spectra, each reference spectrum of the plurality of reference spectra having a stored associated index value, measuring a sequence of spectra in-situ during polishing to obtain measured spectra, for each measured spectrum of the sequence of spectra, finding a best matching reference spectrum to generate a sequence of best matching reference spectra, determining the associated index value for each best matching spectrum from the sequence of best matching reference spectra to generate a sequence of index values, fitting a linear function to the sequence of index values, and halting the polishing either when the linear function matches or exceeds a target index or when the associated index value from the determining step matches or exceeds the target index. | 08-26-2010 |
20100261413 | Determining Physical Property of Substrate - A method of determining a physical property of a substrate includes recording a first spectrum obtained from a substrate, the first spectrum being obtained during a polishing process that alters a physical property of the substrate. The method includes identifying, in a database, at least one of several previously recorded spectra that is similar to the recorded first spectrum. Each of the spectra in the database has a physical property value associated therewith. The method includes generating a signal indicating that a first value of the physical property is associated with the first spectrum, the first value being determined using the physical property value associated with the identified previously recorded spectrum in the database. A system for determining a physical property of a substrate includes a polishing machine, an endpoint determining module, and a database. | 10-14-2010 |
20100284007 | Spectrum Based Endpointing For Chemical Mechanical Polishing - Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra. | 11-11-2010 |
20100297916 | METHODS OF USING OPTICAL METROLOGY FOR FEED BACK AND FEED FORWARD PROCESS CONTROL - A method includes polishing a substrate on a first platen using a first set of parameters, obtaining a plurality of measured spectra from at least two zones, comparing the plurality of measured spectra with a reference spectrum to evaluate the thickness of each of the at least two zones of the substrate, comparing a thickness of a first zone with a thickness of a second zone, determining whether the thickness of the first zone falls within a predetermined range of the thickness of the second zone, and if the thickness does not fall within the predetermined range, at least one of a) adjusting at least one parameter of the first set and polishing a second substrate on the first platen using the adjusted parameters, or b) adjusting at least one parameter of a second set and polishing the substrate on a second platen using the adjusted parameters. | 11-25-2010 |
20110046918 | METHODS AND APPARATUS FOR GENERATING A LIBRARY OF SPECTRA - A method of generating a library from a reference substrate for use in processing product wafers is described. The method includes measuring substrate characteristics at a plurality of well-defined points of a reference substrate, measuring spectra at plurality of measurement points of the reference substrate, there being more measurement points than well-defined points, and associating measured spectra with measured substrate characteristics. | 02-24-2011 |
20110104987 | ENDPOINT METHOD USING PEAK LOCATION OF SPECTRA CONTOUR PLOTS VERSUS TIME - In one aspect, a method of polishing includes polishing a substrate, and receiving an identification of a selected spectral feature and a characteristic of the selected spectral feature to monitor during polishing. The method includes measuring a sequence of spectra of light reflected from the substrate while the substrate is being polished, where at least some of the spectra of the sequence differ due to material being removed during the polishing. The method of polishing includes determining a value of a characteristic of the selected spectral feature for each of the spectra in the sequence of spectra to generate a sequence of values for the characteristic, fitting a function to the sequence of values, and determining either a polishing endpoint or an adjustment for a polishing rate based on the function. | 05-05-2011 |
20110209412 | METHOD OF MAKING POLISHING PAD ASSEMBLY WITH GLASS OR CRYSTALLINE WINDOW - Methods and apparatus for providing a chemical mechanical polishing pad. The pad includes a polishing layer having a top surface and a bottom surface. The pad includes an aperture having a first opening in the top surface and a second opening in the bottom surface. The top surface is a polishing surface. The pad includes a window that includes a first portion made of soft plastic and a crystalline or glass like second portion. The window is transparent to white light. The window is situated in the aperture so that the first portion plugs the aperture and the second portion is on a bottom side of the first portion, wherein the first portion acts a slurry-tight barrier. | 09-01-2011 |
20110256805 | Adaptively Tracking Spectrum Features For Endpoint Detection - A method of controlling polishing includes polishing a substrate, monitoring a substrate during polishing with an in-situ monitoring system, generating a sequence of values from measurements from the in-situ monitoring system, fitting a non-linear function to the sequence of values, determining a projected time at which the non-linear function reaches a target value; and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the projected time. | 10-20-2011 |
20110275167 | Endpoint Method Using Peak Location Of Modified Spectra - A method of optically monitoring a substrate during polishing includes receiving an identification of a selected spectral feature and a characteristic of the selected spectral feature to monitor during polishing, measuring a first spectrum from the substrate during polishing, the first spectrum measured within an initial time following initiation of polishing, measuring a sequence of second spectra from the substrate during polishing, the sequence of second spectra measured after the initial time, for each second spectrum in the sequence of second spectra, removing the first spectrum from the second spectrum to generate a sequence of modified third spectra, determining a value of a characteristic of the selected spectral feature for each third spectrum in the sequence of third spectra to generate a sequence of values for the characteristic, and determining a polishing endpoint or an adjustment for a polishing rate based on the sequence of values. | 11-10-2011 |
20110275281 | Dynamically Tracking Spectrum Features For Endpoint Detection - A method of controlling polishing includes polishing a substrate and receiving an identification of a selected spectral feature, a wavelength range having a width, and a characteristic of the selected spectral feature to monitor during polishing. A sequence of spectra of light from the substrate is measured while the substrate is being polished. A sequence of values of the characteristic of the selected spectral feature is generated from the sequence of spectra. For at least some spectra from the sequence of spectra, a modified wavelength range is generated based on a position of the spectral feature within a previous wavelength range used for a previous spectrum in the sequence of spectra, the modified wavelength range is searched for the selected spectral feature, and a value of a characteristic of the selected spectral feature is determined. | 11-10-2011 |
20110281501 | FEEDBACK FOR POLISHING RATE CORRECTION IN CHEMICAL MECHANICAL POLISHING - A substrate having a plurality of zones is polished and spectra are measured. For each zone, a first linear function fits a sequence of index values associated with reference spectra that best match the measured spectra. A projected time at which a reference zone will reach the target index value is determined based on the first linear function, and for at least one adjustable zone, a polishing parameter adjustment is calculated such that the adjustable zone has closer to the target index at the projected time than without such adjustment. The adjustment is calculated based on a feedback error calculated for a previous substrate. The feedback error for a subsequent substrate is calculated based on a second linear function that fits a sequence of index values associated with reference spectra that best match spectra measured after the polishing parameter is adjusted. | 11-17-2011 |
20110282477 | ENDPOINT CONTROL OF MULTIPLE SUBSTRATES WITH MULTIPLE ZONES ON THE SAME PLATEN IN CHEMICAL MECHANICAL POLISHING - A plurality of substrates are polished simultaneously on the same polishing pad. A sequence of spectra is measured from each zone of each substrate, and for each measured spectrum in the sequence of spectra for each zone of each substrate, a best matching reference spectrum is determined from a library of reference spectra. For each zone of each substrate, a linear function is fit to a sequence of index values associated with the best matching reference spectra. For at least one zone, a projected time at which the zone will reach a target index value is determined based on the linear function, and the polishing parameter for at least one zone on at least one substrate is adjusted such that the at least one zone of the at least one substrate has closer to the target index at the projected time than without such adjustment. | 11-17-2011 |
20110294400 | Determining Physical Property of Substrate - A method of determining a physical property of a substrate includes recording a first spectrum obtained from a substrate, the first spectrum being obtained during a polishing process that alters a physical property of the substrate. The method includes identifying, in a database, at least one of several previously recorded spectra that is similar to the recorded first spectrum. Each of the spectra in the database has a physical property value associated therewith. The method includes generating a signal indicating that a first value of the physical property is associated with the first spectrum, the first value being determined using the physical property value associated with the identified previously recorded spectrum in the database. A system for determining a physical property of a substrate includes a polishing machine, an endpoint determining module, and a database. | 12-01-2011 |
20110301847 | Automatic Initiation Of Reference Spectra Library Generation For Optical Monitoring - A method of generating reference spectra includes polishing a first substrate in a polishing apparatus, measuring a sequence of spectra from the first substrate during polishing with an in-situ optical monitoring system, for each spectrum in the sequence of spectra, determining a best matching reference spectrum from a first plurality of first reference spectra to generate a sequence of reference spectra, calculating a value of a metric of fit of the sequence of spectra to the sequence of reference spectra, comparing the value of the metric of fit to a threshold value and determining whether to generate a second library based on the comparison, and if the second library is determined to be generated, storing the sequence of spectra as a second plurality of reference spectra. | 12-08-2011 |
20110318992 | Adaptively Tracking Spectrum Features For Endpoint Detection - A method of controlling polishing includes polishing a substrate having a second layer overlying a first layer, detecting exposure of the first layer with an in-situ monitoring system, receiving an identification of a selected spectral feature and a characteristic of the selected spectral feature to monitor during polishing, measuring a sequence of spectra of light from the substrate while the substrate is being polished, determining a first value for the characteristic of the feature at the time that the first in-situ monitoring technique detects exposure of the first layer, adding an offset to the first value to generate a second value, and monitoring the characteristic of the feature and halting polishing when the characteristic of the feature is determined to reach the second value. | 12-29-2011 |
20120021672 | Tracking Spectrum Features In Two Dimensions For Endpoint Detection - A method of polishing includes polishing a substrate, receiving an identification of a selected spectral feature to monitor during polishing, measuring a sequence of spectra of light reflected from the substrate while the substrate is being polished, determining a location value and an associated intensity value of the selected spectral feature for each of the spectra in the sequence of spectra to generate a sequence of coordinates, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the sequence of coordinates. At least some of the spectra of the sequence differ due to material being removed during the polishing, and the coordinates are pairs of location values and associated intensity values. | 01-26-2012 |
20120028377 | USING OPTICAL METROLOGY FOR WITHIN WAFER FEED FORWARD PROCESS CONTROL - A method of controlling the polishing of a substrate includes polishing a substrate on a first platen using a first set of parameters, obtaining first and second sequences of measured spectra from first and second regions of the substrate with an in-situ optical monitoring system, generating first and second sequences of values from the first and second sequences of measured spectra, fitting first and second linear functions to the first and second sequences of values, determining a difference between the first linear function and the second linear function, adjusting at least one parameter of a second set of parameters based on the difference, and polishing the substrate on a second platen using the adjusted parameter. | 02-02-2012 |
20120028813 | Selecting Reference Libraries For Monitoring Of Multiple Zones On A Substrate - A method of configuring a polishing monitoring system includes receiving user input selecting a plurality of libraries, each library of the plurality of libraries comprising a plurality of reference spectra for use in matching to measured spectra during polishing, each reference spectrum of the plurality of reference spectra having an associated index value, for a first zone of a substrate, receiving user input selecting a first subset of the plurality of libraries, and for a second zone of the substrate, receiving user input selecting a second subset of the plurality of libraries. | 02-02-2012 |
20120034845 | TECHNIQUES FOR MATCHING MEASURED SPECTRA TO REFERENCE SPECTRA FOR IN-SITU OPTICAL MONITORING - A method of controlling polishing includes storing a library having a plurality of reference spectra, polishing a substrate, measuring a sequence of spectra of light from the substrate during polishing, for each measured spectrum of the sequence of spectra, finding a best matching reference spectrum using a matching technique other than sum of squared differences to generate a sequence of best matching reference spectra, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the sequence of best matching reference spectra. Finding a best matching reference spectrum may include performing a cross-correlation of the measured spectrum with each of two or more of the plurality of reference spectra from the library and selecting a reference spectrum with the greatest correlation to the measured spectrum as a best matching reference spectrum. | 02-09-2012 |
20120096006 | BUILDING A LIBRARY OF SPECTRA FOR OPTICAL MONITORING - A method of controlling polishing includes storing a library having a plurality of reference spectra, polishing a substrate, measuring a sequence of spectra of light from the substrate during polishing, for each measured spectrum of the sequence of spectra, finding a best matching reference spectrum using a matching technique other than sum of squared differences to generate a sequence of best matching reference spectra, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the sequence of best matching reference spectra. Finding a best matching reference spectrum may include performing a cross-correlation of the measured spectrum with each of two or more of the plurality of reference spectra from the library and selecting a reference spectrum with the greatest correlation to the measured spectrum as a best matching reference spectrum. | 04-19-2012 |
20120100642 | Spectra Based Endpointing for Chemical Mechanical Polishing - A computer implemented method of monitoring a polishing process includes, for each sweep of a plurality of sweeps of an optical sensor across a substrate undergoing polishing, obtaining a plurality of current spectra, each current spectrum of the plurality of current spectra being a spectrum resulting from reflection of white light from the substrate, for each sweep of the plurality of sweeps, determining a difference between each current spectrum and each reference spectrum of a plurality of reference spectra to generate a plurality of differences, for each sweep of the plurality of sweeps, determining a smallest difference of the plurality of differences, thus generating a sequence of smallest difference, and determining a polishing endpoint based on the sequence of smallest differences. | 04-26-2012 |
20120196511 | Gathering Spectra From Multiple Optical Heads - A polishing apparatus includes a platen to hold a polishing pad having a plurality of optical apertures, a carrier head to hold a substrate against the polishing pad, a motor to generate relative motion between the carrier head and the platen, and an optical monitoring system. The optical monitoring system includes at least one light source, a common detector, and an optical assembly configured to direct light from the at least one light source to each of a plurality of separated positions in the platen, to direct light from each position of the plurality of separated positions to the substrate as the substrate passes over said each position, to receive reflected light from the substrate as the substrate passes over said each position, and to direct the reflected light from each of the plurality of separated positions to the common detector. | 08-02-2012 |
20120231701 | FEEDBACK FOR POLISHING RATE CORRECTION IN CHEMICAL MECHANICAL POLISHING - A substrate having a plurality of zones is polished and spectra are measured. For each zone, a first linear function fits a sequence of index values associated with reference spectra that best match the measured spectra. A projected time at which a reference zone will reach the target index value is determined based on the first linear function, and for at least one adjustable zone, a polishing parameter adjustment is calculated such that the adjustable zone has closer to the target index at the projected time than without such adjustment. The adjustment is calculated based on a feedback error calculated for a previous substrate. The feedback error for a subsequent substrate is calculated based on a second linear function that fits a sequence of index values associated with reference spectra that best match spectra measured after the polishing parameter is adjusted. | 09-13-2012 |
20120268738 | Construction of Reference Spectra with Variations in Environmental Effects - A method of generating a library of reference spectra includes storing at least one reference spectrum, storing a plurality of different transmission curves, and for at least two transmission curves from the plurality of different transmission curves, calculating a modified reference spectrum from the reference spectrum and the transmission curve to generate a plurality of modified reference spectra. The transmission curves represent distortion to a spectrum introduced by variations in components in an optical path before a substrate surface. | 10-25-2012 |
20120274932 | POLISHING WITH COPPER SPECTRUM - A method of controlling polishing includes polishing a substrate of a non-metallic layer undergoing polishing and a metal layer underlying the non-metallic layer; storing a metal reference spectrum, the metal reference spectrum being a spectrum of light reflected from a same metal material as the metal layer; measuring a sequence of raw spectra of light reflected from the substrate during polishing with an in-situ optical monitoring system; normalizing each raw spectrum in the sequence of spectra to generate a sequence of normalized spectra, of which normalizing includes a division operation where the measured spectrum is in the numerator and the metal reference spectrum is in the denominator; and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least one normalized predetermined spectrum from the sequence of normalized spectra. | 11-01-2012 |
20120276814 | AUTOMATIC SELECTION OF REFERENCE SPECTRA LIBRARY - A computer-implemented method of generating reference spectra includes polishing a plurality of set-up substrates, the plurality of set-up substrates comprising at least three set-up substrates, measuring a sequence of spectra from each of the plurality of set-up substrates during polishing with an in-situ optical monitoring system to provide a plurality of sequences of spectra, generating a plurality of sequences of potential reference spectra from the plurality of sequences of spectra, determining which sequence of potential reference spectra of the plurality of sequences provides a best match to remaining sequences of the plurality of sequences, and storing the sequence of potential reference spectra determined to provide the best match as reference spectra, and selecting and storing the sequence of potential reference spectra. | 11-01-2012 |
20120276815 | VARYING OPTICAL COEFFICIENTS TO GENERATE SPECTRA FOR POLISHING CONTROL - A method of generating a library of reference spectra includes storing an optical model for a layer stack having at a plurality of layers, receiving user input identifying a set of one or more refractive index functions and a set of one or more extinction coefficient functions a first layer from the plurality of layers, wherein the set of one or more refractive index functions includes a plurality of different refractive index functions or the set of one or more extinction coefficient functions includes a plurality of different extinction coefficient functions, and for each combination of a refractive index function from the set of refractive index functions and an extinction coefficient function from the set of extinction coefficient functions, calculating a reference spectrum using the optical model based on the refractive index function, the extinction coefficient function and a first thickness of the first layer. | 11-01-2012 |
20120278028 | GENERATING MODEL BASED SPECTRA LIBRARY FOR POLISHING - A method of generating a library of reference spectra, includes receiving a first spectrum representing a reflectance of a first stack of layers on a substrate, the first stack including a first dielectric layer, receiving a second spectrum representing a reflectance of a second stack layer on the substrate, the second stack including the first dielectric layer and a second dielectric layer that is not in the first stack, receiving user input identifying a plurality of different contribution percentages for at least one of the first stack or the second stack on the substrate, and for each contribution percentage from the plurality of different contribution percentages, calculating a reference spectrum from the first spectrum, the second spectrum and the contribution percentage. | 11-01-2012 |
20120323355 | SPECTROGRAPHIC MONITORING OF A SUBSTRATE DURING PROCESSING USING INDEX VALUES - Methods, systems, and apparatus for spectrographic monitoring of a substrate during chemical mechanical polishing are described. In one aspect, a computer-implemented method includes storing a library having a plurality of reference spectra, each reference spectrum of the plurality of reference spectra having a stored associated index value, measuring a sequence of spectra in-situ during polishing to obtain measured spectra, for each measured spectrum of the sequence of spectra, finding a best matching reference spectrum to generate a sequence of best matching reference spectra, determining the associated index value for each best matching spectrum from the sequence of best matching reference spectra to generate a sequence of index values, fitting a linear function to the sequence of index values, and halting the polishing either when the linear function matches or exceeds a target index or when the associated index value from the determining step matches or exceeds the target index. | 12-20-2012 |
20130059499 | Semi-Quantitative Thickness Determination - While a substrate is polished, it is also irradiated with light from a light source. A current spectrum of the light reflected from the surface of the substrate is measured. A selected peak, having a first parameter value, is identified in the current spectrum. A value of a second parameter associated with the first parameter is determined from a lookup table using a processor. Depending on the value of the second parameter, the polishing of the substrate is changed. An initial spectrum of light reflected from the substrate before the polishing of the substrate can be measured and a wavelength corresponding to a selected peak of the initial spectrum can be determined. | 03-07-2013 |
20130204424 | Adjusting Polishing Rates by Using Spectrographic Monitoring of a Substrate During Processing - A computer-implemented method includes receiving a sequence of current spectra of reflected light from a substrate; comparing each current spectrum from the sequence of current spectra to a plurality of reference spectra from a reference spectra library to generate a sequence of best-match reference spectra; determining a goodness of fit for the sequence of best-match reference spectra; and determining at least one of whether to adjust a polishing rate or an adjustment for the polishing rate, based on the goodness of fit. | 08-08-2013 |
20130237128 | FITTING OF OPTICAL MODEL TO MEASURED SPECTRUM - A method of controlling a polishing operation includes polishing a first layer of a substrate, during polishing, obtaining a sequence over time of measured spectra with an in-situ optical monitoring system, for each measured spectrum from the sequence of measured spectra, fitting an optical model to the measured spectrum, the fitting including finding parameters that provide a minimum difference between an output spectrum of the optical model and the measured spectrum, the parameters including an endpoint parameter and at least one non-endpoint parameter, the fitting generating a sequence of fitted endpoint parameter values, each endpoint parameter value of the sequence associated with one of the spectra of the sequence of measured spectra, and determining at least one of a polishing endpoint or an adjustment of a pressure to the substrate from the sequence of fitted endpoint parameter values. | 09-12-2013 |
20130280989 | USER-INPUT FUNCTIONS FOR DATA SEQUENCES IN POLISHING ENDPOINT DETECTION - A method of controlling polishing includes receiving user input through a graphical user interface selecting a function, the function including at least one parameter that can be varied, polishing a substrate, monitoring a substrate during polishing with an in-situ monitoring system, generating a sequence of values from measurements from the in-situ monitoring system, fitting the function to the sequence of values, the fitting including determining a value of the at least one parameter that provides a best fit of the function to the sequence of values, determining a projected time at which the function equals a target value, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the projected time. | 10-24-2013 |
20130288570 | FITTING OF OPTICAL MODEL WITH DIFFRACTION EFFECTS TO MEASURED SPECTRUM - A method of controlling a polishing operation includes obtaining a sequence over time of measured spectra with an in-situ optical monitoring system during polishing. For each measured spectrum from the sequence an optical model is fit. The optical model includes dimensions of a repeating structure and the fitting includes calculating a output spectrum using diffraction effects of the repeating structure, and parameters of the optical model include an endpoint parameter and a parameter of the repeating structure. The fitting generates the sequence of fitted endpoint parameter values, and at least one of a polishing endpoint or an adjustment of a pressure to the substrate is determined from the sequence of fitted endpoint parameter values. | 10-31-2013 |
20130288571 | FEED FORWARD AND FEED-BACK TECHNIQUES FOR IN-SITU PROCESS CONTROL - During polishing of a substrate at a first platen and prior to a first time, a first sequence of values is obtained for a first zone of the first substrate and a second sequence of values is obtained for a different second zone of the substrate with an in-situ monitoring system. A first function is fit to a portion of the first sequence of values obtained prior to the first time, and a second function is fit to a portion of the second sequence of values obtained prior to the second time. At least one polishing parameter is adjusted based on the first fitted function and the second fitted function so as to reduce an expected difference between the zones. A second substrate is polished on the first platen using an adjusted polishing parameter calculated based on the first fitted function and the second fitted function. | 10-31-2013 |
20130344625 | ENDPOINTING DETECTION FOR CHEMICAL MECHANICAL POLISHING BASED ON SPECTROMETRY - Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra. | 12-26-2013 |
20140039660 | SPECTROGRAPHIC MONITORING OF A SUBSTRATE DURING PROCESSING USING INDEX VALUES - Methods, systems, and apparatus for spectrographic monitoring of a substrate during chemical mechanical polishing are described. In one aspect, a computer-implemented method includes storing a library having a plurality of reference spectra, each reference spectrum of the plurality of reference spectra having a stored associated index value, measuring a sequence of spectra in-situ during polishing to obtain measured spectra, for each measured spectrum of the sequence of spectra, finding a best matching reference spectrum to generate a sequence of best matching reference spectra, determining the associated index value for each best matching spectrum from the sequence of best matching reference spectra to generate a sequence of index values, fitting a linear function to the sequence of index values, and halting the polishing either when the linear function matches or exceeds a target index or when the associated index value from the determining step matches or exceeds the target index. | 02-06-2014 |
20140045282 | Using Spectra to Determine Polishing Endpoints - Methods of determining a polishing endpoint are described using spectra obtained during a polishing sequence. In particular, techniques for using only desired spectra, faster searching methods and more robust rate determination methods are described. | 02-13-2014 |
20140093987 | Residue Detection with Spectrographic Sensor - Detecting residue of a filler material over a patterned underlying layer includes causing relative motion between a probe of an optical metrology system and a substrate, obtaining a plurality of measured spectra with the optical metrology system through the probe from a plurality of different measurement spots within an area on the substrate, comparing each of the plurality of measured spectra to a reference spectrum to generate a plurality of similarity values, the reference spectrum being a spectrum reflected from the filler material, combining the similarity values to generate a scalar value, and determining the presence of residue based on the scalar value. | 04-03-2014 |
20140113524 | ENDPOINTING WITH SELECTIVE SPECTRAL MONITORING - A method of controlling polishing includes polishing a substrate, monitoring the substrate during polishing with an in-situ spectrographic monitoring system to generate a sequence of measured spectra, selecting less than all of the measured spectra to generate a sequence of selected spectra, generating a sequence of values from the sequence of selected spectra, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the sequence of values. | 04-24-2014 |
20140134758 | TECHNIQUES FOR MATCHING SPECTRA - A method of controlling processing of a substrate includes measuring a spectrum reflected from the substrate, for each partition of a plurality of partitions of the measured spectrum, computing a partition value based on the measured spectrum within the partition to generate a plurality of partition values, for each reference spectrum signature of a plurality of reference spectrum signatures, determining a membership function for each partition, for each partition, computing a membership value based on the membership function for the partition and the partition value for the partition to generate a plurality of groups of membership values with each group of the plurality of groups associated with a reference spectrum signature, selecting a best matching reference spectrum signature from the plurality of reference spectra signatures based on the plurality of groups of membership values, and determining a characterizing value associated with the best matching reference spectrum signature. | 05-15-2014 |
20140141695 | Multi-Platen Multi-Head Polishing Architecture - A polishing apparatus includes a plurality of stations supported on a platform, the plurality of stations including at least two polishing stations and a transfer station, each polishing station including a platen to support a polishing pad, a plurality of carrier heads suspended from and movable along a track such that each polishing station is selectively positionable at the stations, and a controller configured to control motion of the carrier heads along the track such that during polishing at each polishing station only a single carrier head is positioned in the polishing station. | 05-22-2014 |
20140141696 | Polishing System with In-Sequence Sensor - A polishing apparatus includes a plurality of stations supported on a platform, the plurality of stations including at least two polishing stations and a transfer station, each polishing station including a platen to support a polishing pad, a plurality of carrier heads suspended from and movable along a track such that each polishing station is selectively positionable at the stations, and a controller configured to control motion of the carrier heads along the track such that during polishing at each polishing station only a single carrier head is positioned in the polishing station. | 05-22-2014 |
20140176949 | Automatic Initiation Of Reference Spectra Library Generation For Optical Monitoring - A method of generating reference spectra includes polishing a first substrate in a polishing apparatus, measuring a sequence of spectra from the first substrate during polishing with an in-situ optical monitoring system, for each spectrum in the sequence of spectra, determining a best matching reference spectrum from a first plurality of first reference spectra to generate a sequence of reference spectra, calculating a value of a metric of fit of the sequence of spectra to the sequence of reference spectra, comparing the value of the metric of fit to a threshold value and determining whether to generate a second library based on the comparison, and if the second library is determined to be generated, storing the sequence of spectra as a second plurality of reference spectra. | 06-26-2014 |
20140242730 | SPECTRAPHIC MONITORING BASED ON PRE-SCREENING OF THEORETICAL LIBRARY - An optical model for a layer stack has a plurality of input parameters, the plurality of input parameters defining a parameter space. A plurality of model spectra are generated by calculating a model spectrum using the optical model for each of a first plurality of different points in the parameter space. A test spectrum of a test substrate is measured. For each model spectrum of the plurality of model spectra, the test spectrum is compared to the model spectrum to determine a difference value, thereby generating a plurality of difference values. A plurality of minima in the plurality of difference values are determined. Reference spectra can be generated clustered around points in the parameter space corresponding to a local minimum from the plurality of minima, or the local minimum can be used as a seed value in fitting the optical model to a measured spectrum. | 08-28-2014 |
20140242877 | SPECTROGRAPHIC METROLOGY WITH MULTIPLE MEASUREMENTS - A method of controlling a polishing system includes transporting a substrate to an in-line optical metrology system positioned in a chemical mechanical polishing system, at the in-line optical metrology system, moving a probe relative to the substrate to measure a plurality of spectra reflected from the substrate at a plurality of different positions on the substrate, for each measured spectrum of the plurality of spectra, determining a goodness of fit of the measured spectrum to a reference spectrum; and adjusting a polishing endpoint or a polishing parameter of the polishing system based on one or more characterizing values generated based on a subset of the plurality of spectra that includes only spectra of the plurality of spectra for which the goodness of fit meets a matching threshold. | 08-28-2014 |
20140242878 | WEIGHTED REGRESSION OF THICKNESS MAPS FROM SPECTRAL DATA - A method of controlling a polishing operation includes measuring a plurality of spectra at a plurality of different positions on a substrate to provide a plurality of measured spectra. For each measured spectrum of the plurality of measured spectra, a characterizing value is generated based on the measured spectrum. For each characterizing value, a goodness of fit of the measured spectrum to another spectrum used in generating the characterizing value is determined. A wafer-level characterizing value map is generated by applying a regression to the plurality of characterizing values with the plurality of goodnesses of fit used as weighting factors in the regression. A polishing endpoint or a polishing parameter of the polishing apparatus is adjusted based on the wafer-level characterizing map, and the substrate or a subsequent substrate is polished in the polishing apparatus with the adjusted polishing endpoint or polishing parameter. | 08-28-2014 |
20140242879 | PATH FOR PROBE OF SPECTROGRAPHIC METROLOGY SYSTEM - A method of operating a polishing system includes polishing a substrate at a polishing station, the substrate held by a carrier head during polishing, transporting the substrate to an in-sequence optical metrology system positioned between the polishing station and another polishing station or a transfer station, measuring a plurality of spectra reflected from the substrate with a probe of the optical metrology system while moving the carrier head to cause the probe to traverse a path across the substrate and while the probe remains stationary, the path across the substrate comprising either a plurality of concentric circles or a plurality of substantially radially aligned arcuate segments, and adjusting a polishing endpoint or a polishing parameter of the polishing system based on one or more characterizing values generated based on at least some of the plurality of spectra. | 08-28-2014 |
20140242880 | OPTICAL MODEL WITH POLARIZATION DIRECTION EFFECTS FOR COMPARISON TO MEASURED SPECTRUM - A method of controlling a polishing operation includes storing an optical model for a layer stack having a plurality of layers. The optical model has a plurality of input parameters, the plurality of input parameters including a first parameter and a second parameter. The second parameter is a polarization angle or a relative contribution between two orthogonal polarizations. A spectrum reflected from the substrate is measured with an in-sequence or in-situ monitoring system to provide a measured spectrum. The optical model is fit to the measured spectrum, or a plurality of reference spectra are calculated using the optical model and a best matching reference spectrum from the plurality of reference spectra is determined. | 08-28-2014 |
20140242881 | FEED FORWARD PARAMETER VALUES FOR USE IN THEORETICALLY GENERATING SPECTRA - A method of controlling a polishing operation is described. A controller stores an optical model for a layer stack having a plurality of layers and a plurality of input parameters including a first parameter and a second parameter. The controller stores data defining a plurality of default values for the first parameter and measures an optical property of a substrate and generates a second value. Using the optical model and the second value and iterating over the first values, a number of reference spectra are calculated. A spectrum is measured and the measured spectrum is matched to the reference spectra and the best matched reference spectrum is determined. The first value of the best matched reference spectrum is determined and is used to adjust a polishing endpoint or a polishing parameter of a polishing apparatus. | 08-28-2014 |
20140242883 | DETERMINATION OF WAFER ANGULAR POSITION FOR IN-SEQUENCE METROLOGY - A polishing apparatus includes a carrier head configured to hold a wafer in a first plane, the wafer having a perimeter and a fiducial, a drive shaft having an axis perpendicular to the first plane and configured to rotate the carrier head about the axis, a light source configured to direct light onto an outer face of the wafer at a position adjacent the perimeter of the wafer; a detector configured to detect the light collected from the wafer while the drive shaft rotates the carrier head and the wafer; and a controller configured to receive a first signal indicating an angular position of the drive shaft and receive a second signal from the detector, the controller configured to determine based on the first signal and the second signal an angular position of the fiducial with respect the carrier head. | 08-28-2014 |
20140316550 | Spectra Based Endpointing for Chemical Mechanical Polishing - A computer implemented method of monitoring a polishing process includes, for each sweep of a plurality of sweeps of an optical sensor across a substrate undergoing polishing, obtaining a plurality of current spectra, each current spectrum of the plurality of current spectra being a spectrum resulting from reflection of white light from the substrate, for each sweep of the plurality of sweeps, determining a difference between each current spectrum and each reference spectrum of a plurality of reference spectra to generate a plurality of differences, for each sweep of the plurality of sweeps, determining a smallest difference of the plurality of differences, thus generating a sequence of smallest difference, and determining a polishing endpoint based on the sequence of smallest differences. | 10-23-2014 |
20140329440 | Dynamically Tracking Spectrum Features For Endpoint Detection - A method of controlling polishing includes polishing a substrate and receiving an identification of a selected spectral feature, a wavelength range having a width, and a characteristic of the selected spectral feature to monitor during polishing. A sequence of spectra of light from the substrate is measured while the substrate is being polished. A sequence of values of the characteristic of the selected spectral feature is generated from the sequence of spectra. For at least some spectra from the sequence of spectra, a modified wavelength range is generated based on a position of the spectral feature within a previous wavelength range used for a previous spectrum in the sequence of spectra, the modified wavelength range is searched for the selected spectral feature, and a value of a characteristic of the selected spectral feature is determined. | 11-06-2014 |
20150024659 | Method of Controlling Polishing - A method of controlling polishing includes polishing a substrate of a non-metallic layer undergoing polishing and a metal layer underlying the non-metallic layer; storing a metal reference spectrum, the metal reference spectrum being a spectrum of light reflected from a same metal material as the metal layer; measuring a sequence of raw spectra of light reflected from the substrate during polishing with an in-situ optical monitoring system; normalizing each raw spectrum in the sequence of spectra to generate a sequence of normalized spectra, of which normalizing includes a division operation where the measured spectrum is in the numerator and the metal reference spectrum is in the denominator; and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least one normalized predetermined spectrum from the sequence of normalized spectra. | 01-22-2015 |