Patent application number | Description | Published |
20080211014 | ULTRA DENSE TRENCH-GATED POWER DEVICE WITH THE REDUCED DRAIN-SOURCE FEEDBACK CAPACITANCE AND MILLER CHARGE - The cellular structure of the power device includes a substrate that has a highly doped drain region. Over the substrate there is a more lightly doped epitaxial layer of the same doping. Above the epitaxial layer is a well region formed of an opposite type doping. Covering the wells is an upper source layer of the first conductivity type that is heavily doped. The trench structure includes a sidewall oxide or other suitable insulating material that covers the sidewalls of the trench. The bottom of the trench is filled with a doped polysilicon shield. An interlevel dielectric such as silicon nitride covers the shield. The gate region is formed by another layer of doped polysilicon. A second interlevel dielectric, typically borophosphosilicate glass (BPSG) covers the gate. In operation, current flows vertically between the source and the drain through a channel in the well when a suitable voltage is applied to the gate. | 09-04-2008 |
20090085074 | TRENCH MOSFET AND METHOD OF MANUFACTURE UTILIZING FOUR MASKS - In accordance with the invention, a trench MOSFET semiconductor device is manufactured in accordance with a process comprising the steps of: providing a heavily doped N+ silicon substrate; utilizing a first mask to define openings for the trench gate and termination; utilizing a second mask as a source mask with openings determining the size and shape of a diffused source junction depth; utilizing a third mask as a contact mask to define contact hole openings; and utilizing a fourth mask as a metal mask, whereby only the first, second, third and fourth masks are utilized in the manufacture of the trench MOSFET semiconductor device. | 04-02-2009 |
20090085099 | TRENCH MOSFET AND METHOD OF MANUFACTURE UTILIZING THREE MASKS - In accordance with the invention a vertical power trench MOSFET semiconductor device comprises P+ body and N+ source diffusions shorted together to prevent second breakdown caused by a parasitic bipolar transistor. The device is manufactured in accordance with a process comprising the steps of: providing a heavily doped N+ silicon substrate; utilizing a first, trench, mask to define a plurality of openings comprising a trench gate and a termination; creating P+ body and N+ source area formations by ion implantation without any masks; utilizing a second, contact, mask to define a gate bus area; and utilizing a third metal mask to separate source metal and gate bus metal and remove metal from a portion of the termination, whereby only three masks are utilized to form the semiconductor device. | 04-02-2009 |
20090085105 | TRENCH MOSFET AND METHOD OF MANUFACTURE UTILIZING TWO MASKS - A method for manufacturing a trench MOSFET semiconductor device comprises: providing a heavily doped N+ silicon substrate; forming an N type epitaxial layer; forming a thick SiO2 layer; creating P body and source area formations by ion implantation without any masks; utilizing a first mask to define openings for a trench gate and a termination; thermally growing a gate oxide layer followed by formation of a thick poly-Silicon refill layer without a mask to define a gate bus area; forming sidewall spacers; forming P+ areas; removing the sidewall spacers; depositing tungsten to fill contacts and vias; depositing a first thin barrier metal layer; depositing a first thick metal layer; utilizing a second metal mask to open a gate bus area; forming second sidewall spacers; depositing a second thin barrier metal layer; depositing a second thick metal layer; and planarizing at least the second thick metal layer and the second thin metal layer to isolate the source metal portions from gate metal portions, whereby the trench MOSFET semiconductor device is manufactured utilizing only first and second masks. | 04-02-2009 |
20090206913 | Edge Termination with Improved Breakdown Voltage - A MOSFET switch which has a low surface electric field at an edge termination area, and also has increased breakdown voltage. The MOSFET switch has a new edge termination structure employing an N-P-N sandwich structure. The MOSFET switch also has a polysilicon field plate configuration operative to enhance any spreading of any depletion layer located at an edge of a main PN junction of the N-P-N sandwich structure. | 08-20-2009 |
20090206924 | Semiconductor Device Structures and Related Processes - Improved highly reliable power RFP structures and fabrication and operation processes. The structure includes plurality of localized dopant concentrated zones beneath the trenches of RFPs, either floating or extending and merging with the body layer of the MOSFET or connecting with the source layer through a region of vertical doped region. This local dopant zone decreases the minority carrier injection efficiency of the body diode of the device and alters the electric field distribution during the body diode reverse recovery. | 08-20-2009 |
20090294892 | Edge Termination for Semiconductor Devices - A high-voltage termination structure includes a peripheral voltage-spreading network. One or more trench structures are connected at least partly in series between first and second power supply voltages. The trench structures include first and second current-limiting structures connected in series with a semiconductor material, and also includes permanent charge in a trench-wall dielectric. The current-limiting structures in the trench structures are jointly connected in a series-parallel ladder configuration. The current-limiting structures, in combination with the semiconductor material, provide a voltage distribution between the core portion and the edge portion. | 12-03-2009 |
20090309156 | Super Self-Aligned Trench MOSFET Devices, Methods, and Systems - A manufacturing process and design structure for a super self-aligned trench power MOSFET. A plurality of super self-aligned trenches of different depths are formed into the body layer and epitaxial layers, preferably by using a multilayer stack of dielectric material etched to form spacers. Respective trenches contain gate conductors, body-contact conductors, and preferably a third trench containing a recessed field plate. This results in a MOSFET structure having high cell density and low gate charges and gate-drain charges. | 12-17-2009 |
20100013552 | MOSFET Switch with Embedded Electrostatic Charge - A vertical device structure includes a volume of semiconductor material, laterally adjoining a trench having insulating material on sidewalls thereof. A gate electrode within the trench is capacitively coupled through the insulating material to a first portion of the semiconducting material. Some portions of the insulating material contain fixed electrostatic charge in a density high enough to invert a second portion of the semiconductor material when no voltage is applied. The inverted portions can be used as induced source or drain extensions, to assure that parasitic are reduced without increasing on-resistance. | 01-21-2010 |
20100214016 | Trench Device Structure and Fabrication - A vertical-current-flow device includes a trench which includes an insulated gate and which extends down into first-conductivity-type semiconductor material. A phosphosilicate glass layer is positioned above the insulated gate and a polysilicon layer is positioned above the polysilicate glass layer. Source and body diffusions of opposite conductivity types are positioned adjacent to a sidewall of the trench. A drift region is positioned to receive majority carriers which have been injected by the source, and which have passed through the body diffusion. A drain region is positioned to receive majority carriers which have passed through the drift region. The gate is capacitively coupled to control inversion of a portion of the body region. As an alternative, a dielectric layer may be used in place of the doped glass where permanent charge is positioned in the dielectric layer. | 08-26-2010 |
20100219462 | MOS-Gated Power Devices, Methods, and Integrated Circuits - MOS-gated devices, related methods, and systems for vertical power and RF devices including an insulated trench and a gate electrode. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. Permanent electrostatic charges are included in said insulation material. A conductive shield layer is positioned above the insulated trench, to reduce parasitic capacitances. | 09-02-2010 |
20100219468 | POWER DEVICE STRUCTURES AND METHODS - Vertical power devices which include an insulated trench containing insulating material and a gate electrode, and related methods. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. A layer of permanent charge, at or near the sidewall of the trench, provides charge balancing for the space charge in the depleted semiconductor material during the OFF state. A conductive shield layer is positioned below the gate electrode in the insulating material, and reduces capacitive coupling between the gate and the lower part of the trench. This reduces switching losses. In other embodiments, a planar gate electrode controls horizontal carrier injection into the vertical conduction pathway along the trench, while a shield plate lies over the trench itself to reduce capacitive coupling. | 09-02-2010 |
20110006361 | Integrated Power Supplies and Combined High-Side Plus Low-Side Switches - The present application discloses new approaches to integrated power. Two new classes of structures each provide an integrated phase leg, in a process which can easily be integrated with low-voltage and/or peripheral circuits: in one class of disclosed structures, a lateral PMOS device is combined with an NMOS device which has predominantly vertical current flow. In another class of embodiments, a predominantly vertical n-channel device is used for the low-side switch, in combination with a lateral n-channel device. In either case, the common output node is preferably brought out at a backside contact. This device structure is advantageously used to construct complete power supply and/or voltage conversions circuits on a single chip (perhaps connected to external passive reactances). | 01-13-2011 |
20110079843 | POWER SEMICONDUCTOR DEVICES, METHODS, AND STRUCTURES WITH Embedded Dielectric Layers Containing Permanent Charges - Power devices using refilled trenches with permanent charge at or near their sidewalls. These trenches extend vertically into a drift region. | 04-07-2011 |
20110169103 | DEVICES, COMPONENTS AND METHODS COMBINING TRENCH FIELD PLATES WITH IMMOBILE ELECTROSTATIC CHARGE - N-channel power semiconductor devices in which an insulated field plate is coupled to the drift region, and immobile electrostatic charge is also present at the interface between the drift region and the insulation around the field plate. The electrostatic charge permits OFF-state voltage drop to occur near the source region, in addition to the voltage drop which occurs near the drain region (due to the presence of the field plate). | 07-14-2011 |
20110193131 | Devices, Structures, and Methods Using Self-Aligned Resistive Source Extensions - Devices, structures, and related methods for IGBTs and the like which include a self-aligned series resistance at the source-body junction to avoid latchup. The series resistance is achieved by using a charged dielectric, and/or by using a dielectric which provides a source of dopant atoms of the same conductivity type as the source region, at a sidewall adjacent to the source region. | 08-11-2011 |
20110254088 | Power MOSFET With Embedded Recessed Field Plate and Methods of Fabrication - Semiconductor power devices, and related methods, wherein a recessed contact makes lateral ohmic contact to the source diffusion, but is insulated from the underlying recessed field plate (RFP). Such an insulated RFP is here referred to as an embedded recessed field plate (ERFP). | 10-20-2011 |
20110298043 | Semiconductor Device Structures and Related Processes - Improved highly reliable power RFP structures and fabrication and operation processes. The structure includes plurality of localized dopant concentrated zones beneath the trenches of RFPs, either floating or extending and merging with the body layer of the MOSFET or connecting with the source layer through a region of vertical doped region. This local dopant zone decreases the minority carrier injection efficiency of the body diode of the device and alters the electric field distribution during the body diode reverse recovery. | 12-08-2011 |
20120032258 | Semiconductor Device Structures and Related Processes - Improved highly reliable power RFP structures and fabrication and operation processes. The structure includes plurality of localized dopant concentrated zones beneath the trenches of RFPs, either floating or extending and merging with the body layer of the MOSFET or connecting with the source layer through a region of vertical doped region. This local dopant zone decreases the minority carrier injection efficiency of the body diode of the device and alters the electric field distribution during the body diode reverse recovery. | 02-09-2012 |
20120043602 | Power MOSFET and Its Edge Termination - Improved MOSFET structures and processes, where multiple polysilicon embedded regions are introduced into the n+ source contact area. A top poly Field Plate is used to shield the electric field from penetrating into the channel, so that a very short channel can be used without jeopardizing the device drain-source leakage current. A bottom poly Field Plate is used to modulate the electric field distribution in the drift region such that a more uniform field distribution can be obtained. | 02-23-2012 |
20120098055 | Power Semiconductor Devices, Structures, and Related Methods - Power semiconductor devices, and related methods, where majority carrier flow is divided into paralleled flows through two drift regions of opposite conductivity types. | 04-26-2012 |
20120098056 | TRENCH DEVICE STRUCTURE AND FABRICATION - A vertical-current-flow device includes a trench which includes an insulated gate and which extends down into first-conductivity-type semiconductor material. A phosphosilicate glass layer is positioned above the insulated gate and a polysilicon layer is positioned above the polysilicate glass layer. Source and body diffusions of opposite conductivity types are positioned adjacent to a sidewall of the trench. A drift region is positioned to receive majority carriers which have been injected by the source, and which have passed through the body diffusion. A drain region is positioned to receive majority carriers which have passed through the drift region. The gate is capacitively coupled to control inversion of a portion of the body region. As an alternative, a dielectric layer may be used in place of the doped glass where permanent charge is positioned in the dielectric layer. | 04-26-2012 |
20120187473 | Edge Termination With Improved Breakdown Voltage - A MOSFET switch which has a low surface electric field at an edge termination area, and also has increased breakdown voltage. The MOSFET switch has a new edge termination structure employing an N-P-N sandwich structure. The MOSFET switch also has a polysilicon field plate configuration operative to enhance any spreading of any depletion layer located at an edge of a main PN junction of the N-P-N sandwich structure. | 07-26-2012 |
20120319199 | Trench Gated Power Device With Multiple Trench Width and its Fabrication Process - Power devices, and related process, where both gate and field plate trenches have multiple stepped widths, using self-aligned process steps. | 12-20-2012 |
20130164895 | Trench-Gated Power Devices with Two Types of Trenches and Reliable Polycidation - Methods and systems for power semiconductor devices and structures with silicide cladding on both gates and field plates. Sidewall spacers, e.g. of silicon nitride, avoid lateral shorts or leakage between the gate silicide and the source region. A source metallization makes lateral contact to the shallow n++ source, and also makes contact to the field plate silicide and the p+ body contact region. | 06-27-2013 |
20140042525 | LATERAL TRANSISTORS AND METHODS WITH LOW-VOLTAGE-DROP SHUNT TO BODY DIODE - Methods and systems for power semiconductor devices integrating multiple quasi-vertical transistors on a single chip. Multiple power transistors (or active regions) are paralleled, but one transistor has a lower threshold voltage. This reduces the voltage drop when the transistor is forward-biased. In an alternative embodiment, the power device with lower threshold voltage is simply connected as a depletion diode, to thereby shunt the body diodes of the active transistors, without affecting turn-on and ON-state behavior. | 02-13-2014 |
20140042535 | TRENCH TRANSISTORS AND METHODS WITH LOW-VOLTAGE-DROP SHUNT TO BODY DIODE - Methods and systems for power semiconductor devices integrating multiple trench transistors on a single chip. Multiple power transistors (or active regions) are paralleled, but one transistor has a lower threshold voltage. This reduces the voltage drop when the transistor is forward-biased. In an alternative embodiment, the power device with lower threshold voltage is simply connected as a depletion diode, to thereby shunt the body diodes of the active transistors, without affecting turn-on and ON-state behavior. | 02-13-2014 |
20140054684 | Power Semiconductor Devices, Structures, and Related Methods - Power semiconductor devices, and related methods, where majority carrier flow is divided into paralleled flows through two drift regions of opposite conductivity types. | 02-27-2014 |
20140054686 | DEVICES, COMPONENTS AND METHODS COMBINING TRENCH FIELD PLATES WITH IMMOBILE ELECTROSTATIC CHARGE - N-channel power semiconductor devices in which an insulated field plate is coupled to the drift region, and immobile electrostatic charge is also present at the interface between the drift region and the insulation around the field plate. The electrostatic charge permits OFF-state voltage drop to occur near the source region, in addition to the voltage drop which occurs near the drain region (due to the presence of the field plate). | 02-27-2014 |
20140054741 | POWER SEMICONDUCTOR DEVICES, METHODS, AND STRUCTURES WITH EMBEDDED DIELECTRIC LAYERS CONTAINING PERMANENT CHARGES - Power devices using refilled trenches with permanent charge at or near their sidewalls. These trenches extend vertically into a drift region. | 02-27-2014 |
20140117367 | DEVICES, STRUCTURES, AND METHODS USING SELF-ALIGNED RESISTIVE SOURCE EXTENSIONS - Devices, structures, and related methods for IGBTs and the like which include a self-aligned series resistance at the source-body junction to avoid latchup. The series resistance is achieved by using a charged dielectric, and/or by using a dielectric which provides a source of dopant atoms of the same conductivity type as the source region, at a sidewall adjacent to the source region. | 05-01-2014 |
20140117439 | MOS-Gated Power Devices, Methods, and Integrated Circuits - MOS-gated devices, related methods, and systems for vertical power and RF devices including an insulated trench and a gate electrode. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. Permanent electrostatic charges are included in said insulation material. A conductive shield layer is positioned above the insulated trench, to reduce parasitic capacitances. | 05-01-2014 |
20140117441 | POWER DEVICE STRUCTURES AND METHODS - Vertical power devices which include an insulated trench containing insulating material and a gate electrode, and related methods. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. A layer of permanent charge, at or near the sidewall of the trench, provides charge balancing for the space charge in the depleted semiconductor material during the OFF state. A conductive shield layer is positioned below the gate electrode in the insulating material, and reduces capacitive coupling between the gate and the lower part of the trench. This reduces switching losses. In other embodiments, a planar gate electrode controls horizontal carrier injection into the vertical conduction pathway along the trench, while a shield plate lies over the trench itself to reduce capacitive coupling. | 05-01-2014 |
20140239386 | Trench Gated Power Device With Multiple Trench Width and its Fabrication Process - Power devices, and related process, where both gate and field plate trenches have multiple stepped widths, using self-aligned process steps. | 08-28-2014 |
20140252463 | SCHOTTKY AND MOSFET+SCHOTTKY STRUCTURES, DEVICES, AND METHODS - Power devices which include trench Schottky barrier diodes and also (preferably) trench-gate transistors. Isolation trenches flank both the gate regions and the diode mesas, and have an additional diffusion below the bottom of the isolation trenches. The additional diffusion helps to reduce the electric field (and leakage), when the device is in the OFF state, at both the Schottky barrier and at the body diode. | 09-11-2014 |
20150076593 | POWER DEVICES, STRUCTURES, COMPONENTS, AND METHODS USING LATERAL DRIFT, FIXED NET CHARGE, AND SHIELD - Lateral power devices where immobile electrostatic charge is emplaced in dielectric material adjoining the drift region. A shield gate is interposed between the gate electrode and the drain, to reduce the Miller charge. In some embodiments the gate electrode is a trench gate, and in such cases the shield electrode too is preferably vertically extended. | 03-19-2015 |