Patent application number | Description | Published |
20100102360 | Method for producing group III nitride semiconductor and template substrate - The present invention provides a method for producing a Group III nitride semiconductor. The method includes forming a groove in a surface of a growth substrate through etching; forming a buffer film on the groove-formed surface of the growth substrate through sputtering; heating, in an atmosphere containing hydrogen and ammonia, the substrate to a temperature at which a Group III nitride semiconductor of interest is grown; and epitaxially growing the Group III nitride semiconductor on side surfaces of the groove at the growth temperature. The thickness of the buffer film or the growth temperature is regulated so that the Group III nitride semiconductor is grown primarily on the side surfaces of the groove in a direction parallel to the main surface of the growth substrate. The thickness of the buffer film is regulated to be smaller than that of a buffer film which is employed for epitaxially growing the Group III nitride semiconductor on a planar growth substrate uniformly in a direction perpendicular to the growth substrate. The growth temperature is regulated to be lower than a temperature at which the Group III nitride semiconductor is epitaxially grown on a planar growth substrate uniformly in a direction perpendicular to the growth substrate. The growth temperature is preferably 1,020 to 1,100° C. The buffer film employed is an AlN film having a thickness of 150 Å or less. | 04-29-2010 |
20110240956 | Group III nitride semiconductor light-emitting device - The present invention provides a Group III nitride semiconductor light-emitting device whose main surface is a plane which provides an internal electric field of zero, and which exhibits improved emission performance. The light-emitting device includes a sapphire substrate which has, in a surface thereof, a plurality of dents which are arranged in a stripe pattern as viewed from above; an n-contact layer formed on the dented surface of the sapphire substrate; a light-emitting layer formed on the n-contact layer; an electron blocking layer formed on the light-emitting layer; a p-contact layer formed on the electron blocking layer; a p-electrode; and an n-electrode. The electron blocking layer has a thickness of 2 to 8 nm and is formed of Mg-doped AlGaN having an Al compositional proportion of 20 to 30%. | 10-06-2011 |
20110240957 | Group lll nitride semiconductor light-emitting device - The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved emission performance without increasing driving voltage. The Group III nitride semiconductor light-emitting device includes at least an n-type-layer-side cladding layer, a light-emitting layer, and a p-type-layer-side cladding layer, each of the layers being formed of a Group III nitride semiconductor. The n-type-layer-side cladding layer is a superlattice layer having a periodic structure including an In | 10-06-2011 |
20110244610 | METHOD FOR PRODUCING GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - The present invention provides a method for producing a Group III nitride semiconductor light-emitting device whose main surface is a plane that provides an internal electric field of zero, and which exhibits improved light extraction performance. In the production method, one surface of an a-plane sapphire substrate is subjected to dry etching, to thereby form an embossment pattern having a plurality of mesas which are arranged in a honeycomb-dot pattern as viewed from above; and an n-type layer, a light-emitting layer, and a p-type layer, each of which is formed of a Group III nitride semiconductor layer having an m-plane main surface, are sequentially stacked on the surface of the sapphire substrate on which the mesas are formed. Subsequently, a p-electrode is formed on the p-type layer, and the p-electrode is bonded to a support substrate via a metal layer. Next, the sapphire substrate is removed through the laser lift-off process. On the thus-exposed surface of the n-type layer is formed an embossment pattern having dents provided through transfer of the mesas of the embossment pattern of the sapphire substrate. Then, the emboss-patterned surface of the n-type layer is subjected to wet etching, to thereby form numerous etched pits. | 10-06-2011 |
20120126241 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE AND PRODUCTION METHOD THEREFOR - A Group III nitride semiconductor light-emitting device includes a sapphire substrate having an embossment on a surface thereof; and an n-type layer, a light-emitting layer, and a p-type layer, which are sequentially stacked on the embossed surface of the sapphire substrate via a buffer layer, and each of which is formed of a Group HI nitride semiconductor. The embossment has a structure including a first stripe-pattern embossment which is formed on a surface of the sapphire substrate, and whose stripe direction corresponds to the x-axis direction; and a second stripe-pattern embossment which is formed atop the first stripe-pattern embossment, and whose stripe direction corresponds to the y-axis direction, the y-axis direction being orthogonal to the x-axis direction. | 05-24-2012 |
20120135557 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - A method for producing a Group III nitride semiconductor light-emitting device includes forming a first stripe-pattern embossment on the top surface of a sapphire substrate, so that first grooves parallel to the x-axis direction (the c-axis direction of the sapphire substrate) are periodically arranged at specific intervals. Subsequently, an insulating film is formed over the entire surface of the first stripe-pattern embossment. Next, a second stripe-pattern embossment is formed so that second grooves, each having a flat bottom surface, are periodically arranged at specific intervals and parallel to the y-axis direction, which is orthogonal to the x-axis direction. A GaN crystal is grown through MOCVD on side surfaces of each second groove of the sapphire substrate, to thereby form, on the sapphire substrate, an m-plane GaN base layer. An LED device structure is formed on the base layer, to thereby produce a light-emitting device. | 05-31-2012 |
20120248407 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - A Group III nitride semiconductor light-emitting device includes a light-emitting layer having a multiple quantum structure including an Al | 10-04-2012 |
20120309124 | METHOD FOR PRODUCING A GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - The present invention provides a method for producing a Group III nitride semiconductor light-emitting device whose driving voltage is reduced. In the production method, a p cladding layer has a superlattice structure in which a p-AlGaN layer having a thickness of 0.5 nm to 10 nm and an InGaN layer are alternately deposited. A growth temperature of the p-AlGaN layer is 800° C. to 950° C. The InGaN layer having a thickness of one to two monolayers is formed on the p-AlGaN layer, by stopping the supply of TMA, introducing TMI, and increasing the supply amount of Ga source gas while maintaining the p-AlGaN layer at the growth temperature. Thus, the thickness of the p cladding layer can be reduced while maintaining good crystal quality, thereby reducing the driving voltage. | 12-06-2012 |
20130015487 | SEMICONDUCTOR LIGHT-EMITTING DEVICEAANM Okuno; KojiAACI Kiyosu-shiAACO JPAAGP Okuno; Koji Kiyosu-shi JP - To improve light extraction efficiency. | 01-17-2013 |
20130059407 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE AND PRODUCTION METHOD THEREFOR - On a light-emitting layer, a p cladding layer of AlGaInN doped with Mg is formed at a temperature of 800° C. to 950° C. Subsequently, on the p cladding layer, a capping layer of undoped GaN having a thickness of 5 Å to 100 Å is formed at the same temperature as employed for a p cladding layer. Next, the temperature is increased to the growth temperature contact layer in the subsequent process. Since the capping layer is formed, and the surface of the p cladding layer is not exposed during heating, excessive doping of Mg or mixture of impurities into the p cladding layer is suppressed. The deterioration of characteristics of the p cladding layer is prevented. Then, on the capping layer, a p contact layer is formed at a temperature of 950° C. to 1100° C. | 03-07-2013 |
20130161586 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE AND PRODUCTION METHOD THEREFOR - The present invention provides a Group III nitride semiconductor light-emitting device which is intended to relax stress applied to a light-emitting layer. The light-emitting device includes an MQW layer, and an n-side superlattice layer formed below the MQW layer. The n-side superlattice layer is formed by repeatedly depositing layer units, each unit including an InGaN layer, a GaN layer, and an n-GaN layer which are sequentially deposited from the side of the sapphire substrate. In the n-side superlattice layer, an InGaN layer more proximal to the MQW layer has a higher In compositional proportion. The In compositional proportion of the InGaN layer (which is most proximal to the MQW layer) of the n-side superlattice layer is 70% to 100% of the In compositional proportion of the InGaN layer (which is most proximal to the n-side superlattice layer) of the MQW layer. | 06-27-2013 |
20130256743 | PRODUCTION METHOD FOR GROUP III NITRIDE SEMICONDUCTOR AND GROUP III NITRIDE SEMICONDUCTOR - A method for producing a Group III nitride semiconductor comprising forming mesas on a main surface of a substrate, and growing Group III nitride semiconductor in a c-axis direction thereof, wherein the plane most parallel to the side surfaces of the mesas or the dents among the low-index planes of growing Group III nitride semiconductor is a m-plane (1-100), and when a projected vector obtained by orthogonally projecting a normal vector of the processed side surface to the main surface is defined as a lateral vector, an angle between the lateral vector and a projected vector obtained by orthogonally projecting a normal vector of the m-plane of the growing Group III nitride semiconductor to the main surface is 0.5° or more and 6° or less. | 10-03-2013 |
20130260541 | METHOD FOR PRODUCING Ga-CONTAINING GROUP III NITRIDE SEMICONDUCTOR - A method for producing a Ga-containing group III nitride semiconductor having reduced threading dislocation is disclosed. A buffer layer in a polycrystal, amorphous or polycrystal/amorphous mixed state, comprising AlGaN is formed on a substrate. The substrate having the buffer layer formed thereon is heat-treated at a temperature higher than a temperature at which a single crystal of a Ga-containing group III nitride semiconductor grows on the buffer layer and at a temperature that the Ga-containing group III nitride semiconductor does not grow, to reduce crystal nucleus density of the buffer layer as compared with the density before the heat treatment. After the heat treatment, the temperature of the substrate is decreased to a temperature that the Ga-containing group III nitride semiconductor grows, the temperature is maintained, and the Ga-containing group III nitride semiconductor is grown on the buffer layer. | 10-03-2013 |
20130299778 | Group III Nitride Semiconductor Light-Emitting Device Including a Superlatice Layer - A Group III nitride semiconductor light-emitting device includes at least an n-type-layer-side cladding layer, a light-emitting layer, and a p-type-layer-side cladding layer, each of the layers being formed of a Group III nitride semiconductor. The n-type-layer-side cladding layer is a superlattice layer having a periodic structure including an In | 11-14-2013 |
20130341636 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE AND PRODUCTION METHOD THEREFOR - The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved light extraction efficiency. An AlGaN semiconductor layer is formed in contact with and on a p-GaN p-contact layer, and an ITO transparent electrode is formed in contact with and on the semiconductor layer. The semiconductor layer comprises AlGaN having an Al composition ratio of 10 mol % to 50 mol %, and has a thickness of 2 Å to 50 Å. The semiconductor layer has a refractive index at an emission wavelength lower than that of the p-contact layer, and larger than that of the transparent electrode. By forming such a semiconductor layer, the reflection is suppressed between the p-contact layer and the transparent electrode, thereby improving the light extraction efficiency. | 12-26-2013 |
20140084241 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE AND METHOD FOR PRODUCING THE SAME - The invention provides a Group III nitride semiconductor light-emitting device in which the strain in the light-emitting layer is relaxed, thereby attaining high light emission efficiency, and a method for producing the device. The light-emitting device of the present invention has a substrate, a low-temperature buffer layer, an n-type contact layer, a first ESD layer, a second ESD layer, an n-side superlattice layer, a light-emitting layer, a p-side superlattice layer, a p-type contact layer, an n-type electrode N | 03-27-2014 |
20140084242 | GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - The present invention provides a Group III nitride semiconductor light-emitting device which exhibits improved light emission efficiency. The light-emitting layer has a MQW structure in which a plurality of layer units are repeatedly deposited, each layer unit comprising a well layer, a capping layer, and a barrier layer sequentially deposited. The well layer is formed of InGaN, the capping layer has a structure in which a GaN layer and an AlGaN layer are deposited in this order on the well layer, and the barrier layer is formed of AlGaN. The AlGaN layer has a higher Al composition ratio than that of the barrier layer. The AlGaN layer in the former portion has a lower Al composition ratio than that of the AlGaN layer in the latter portion when the light-emitting layer is divided into a former portion at the n-cladding layer side and a latter portion at the p-cladding layer side in a thickness direction. | 03-27-2014 |
20140087508 | METHOD FOR PRODUCING GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE - The present invention provides a method for producing a Group III nitride semiconductor light-emitting device wherein a p-cladding layer has a uniform Mg concentration. A p-cladding layer having a superlattice structure in which AlGaN and InGaN are alternately and repeatedly deposited is formed in two stages of the former process and the latter process where the supply amount of the Mg dopant gas is different. The supply amount of the Mg dopant gas in the latter process is half or less than that in the former process. The thickness of a first p-cladding layer formed in the former process is 60% or less than that of the p-cladding layer, and 160 Å or less. | 03-27-2014 |
20140167222 | METHOD FOR PRODUCING GROUP III NITRIDE SEMICONDUCTOR AND TEMPLATE SUBSTRATE - A semiconductor substrate includes a sapphire substrate including an a-plane main surface and a groove in a surface thereof, the groove includes side surfaces and a bottom surface, and a Group III nitride semiconductor layer formed on the sapphire substrate. Both side surfaces of the groove assume a c-plane of sapphire. An axis perpendicular to one of the side surfaces of the groove of the Group III nitride semiconductor layer assumes a c-axis of Group III nitride semiconductor. A plane parallel to the main surface of the sapphire substrate of the Group III nitride semiconductor layer assumes an m-plane of Group III nitride semiconductor. | 06-19-2014 |
20140264415 | Group III Nitride Semiconductor Light-Emitting Device and Method for Producing the Same - The present invention provides a Group III nitride semiconductor light-emitting device in which a flat semiconductor layer is grown on a sapphire substrate provided with an uneven shape, and a method for producing the same. When the area ratio R of the flat surface area S on the main surface to the total area K of the sapphire substrate is 0.1 or more to less than 0.5, in formation of the semiconductor layer on the sapphire substrate having an uneven shape on the main surface thereof, at least two types of gases: a raw material gas containing a Group III element and a raw material gas containing Group V element are supplied so as to satisfy the equation 1,000≦Y/(2×R)≦1,200. In the equation, Y is the partial pressure ratio of the raw material gas containing Group V element to the raw material gas containing Group III element. | 09-18-2014 |
20140353804 | Method for Producing Group III Nitride Semiconductor and Group III Nitride Semiconductor - A first side surface of post of the first stripe is formed so that a plane which is most parallel to the first side surface among low-index planes of the growing Group III nitride semiconductor is a m-plane (10-10), and a first angle between the first lateral vector obtained by orthogonally projecting a normal vector of the first side surfaces to the main surface and a m-axis projected vector obtained by orthogonally projecting a normal vector of the m-plane of the growing semiconductor to the main surface is from 0.5° to 6°. A second side surface of post of the second stripe is formed so that a plane which is most parallel to the second side surface among low-index planes of the growing semiconductor is an a-plane (11-20), and a second angle between the second lateral vector and an a-axis projected vector of the a-plane is from 0° to 10°. | 12-04-2014 |