Abstract: A method of manufacturing a gate structure for gallium nitride (GaN) high electron mobility transistor (HEMT) includes orderly forming a channel layer, a barrier layer, a doped GaN layer, an undoped GaN layer, and an insulating layer on a substrate, and then removing a portion of the insulating layer to form a trench. A gate metal layer is formed on the substrate to cover the insulating layer and the trench, and then a mask layer aligned with the trench is formed on the gate metal layer, wherein the mask layer partially overlaps the insulating layer. By using the mask layer as an etching mask, the exposed gate metal layer and the underlying insulating layer, the undoped GaN layer and the doped GaN layer are removed, and then the mask layer is removed.

Abstract: A Schottky contact structure for a semiconductor device having a Schottky contact and an electrode for the contact structure disposed on the contact. The Schottky contact comprises: a first layer of a first metal in Schottky contact with a semiconductor; a second layer of a second metal on the first layer; a third layer of the first metal on the second layer; and a fourth layer of the second metal on the third layer. The electrode for the Schottky contact structure disposed on the Schottky contact comprises a third metal, the second metal providing a barrier against migration between the third metal and the first metal.

Abstract: Methods for improving the performance and lifetime of irradiated photovoltaic cells are disclosed, whereby Group-V elements, and preferably nitrogen, are used to dope semiconductor GaAs-based subcell alloys.

Abstract: A power device manufacturing method is provided. The power device manufacturing method may perform patterning of regions on which a source electrode and a drain electrode are to be formed, may regrow n+-gallium nitride (GaN) and p+-GaN in the patterned regions and thus, a thin film crystal may not be damaged. Also, a doping concentration of n+-GaN or p+-GaN may be adjusted, an ohmic resistance in the source electrode region and the drain electrode region may decrease, and a current density may increase. The power device manufacturing method may regrow n+-GaN and p+-GaN at a high temperature after an n-GaN layer and a p-GaN layer are patterned. Accordingly, a thin film crystal may not be damaged and thus, a reliability may be secured, and an annealing process may not be additionally performed and thus, a process may be simplified and a cost may be reduced.

Abstract: A semiconductor device includes a first layer and a second layer over the first layer. The first and second layers are configured to form an electron gas layer at an interface of the first and second layers. The semiconductor device also includes an Ohmic contact and multiple conductive vias through the second layer. The conductive vias are configured to electrically couple the Ohmic contact to the electron gas layer. The conductive vias could have substantially vertical sidewalls or substantially sloped sidewalls, or the conductive vias could form a nano-textured surface on the Ohmic contact. The first layer could include Group III-nitride nucleation, buffer, and channel layers, and the second layer could include a Group III-nitride barrier layer.

Abstract: A semiconductor structure having a silicon substrate having a <111> crystallographic orientation, an insulating layer disposed over a first portion of the silicon substrate, a silicon layer having a <100> orientation disposed over the insulating layer, and a non-nitride column III-V semiconductor layer or column II-VI semiconductor layer having the same <111> crystallographic orientation as the silicon substrate, the non-nitride column III-V semiconductor layer or column II-VI semiconductor layer being in direct contact with a second portion of the silicon substrate. A column III-nitride is disposed on the surface of the third portion of the substrate.

Abstract: A method of manufacturing a vertical structure light emitting diode device, the method including: sequentially forming a first conductivity type III-V group compound semiconductor layer, an active layer, and a second conductivity type III-V group compound semiconductor layer on a substrate for growth; bonding a conductive substrate to the second conductivity type III-V group compound semiconductor layer; removing the substrate for growth from the first conductivity type III-V group compound semiconductor layer; and forming an electrode on an exposed portion of the first conductive III-V group compound semiconductor layer due to the removing the substrate for growth, wherein the bonding a conductive substrate comprises partially heating a metal bonding layer by applying microwaves to a bonding interface while bringing the metal bonding layer into contact with the bonding interface.

Abstract: A low contact resistance semiconductor structure includes a substrate, a semiconductor stacked layer, a low contact resistance layer and a transparent conductive layer. The low contact resistance layer is formed on one side of a P-type GaN layer of the semiconductor stacked layer. The low contact resistance layer is formed at a thickness smaller than 100 Angstroms and made of a material selected from the group consisting of aluminum, gallium, indium, and combinations thereof. Through the low contact resistance layer, the resistance between the P-type GaN layer and transparent conductive layer can be reduced and light emission efficiency can be improved when being used on LEDs. The method of fabricating the low contact resistance semiconductor structure of the invention forms a thin and consistent low contact resistance layer through a Metal Organic Chemical Vapor Deposition (MOCVD) method to enhance matching degree among various layers.

Abstract: A method for fabricating edge termination structures in gallium nitride (GaN) materials includes providing a n-type GaN substrate having a first surface and a second surface, forming an n-type GaN epitaxial layer coupled to the first surface of the n-type GaN substrate, and forming a growth mask coupled to the n-type GaN epitaxial layer. The method further includes patterning the growth mask to expose at least a portion of the n-type GaN epitaxial layer, and forming at least one p-type GaN epitaxial structure coupled to the at least a portion of the n-type GaN epitaxial layer. The at least one p-type GaN epitaxial structure comprises at least one portion of an edge termination structure. The method additionally includes forming a first metal structure electrically coupled to the second surface of the n-type GaN substrate.

Abstract: In an n-type semiconductor layer that contains gallium (Ga), contact resistance is to be suppressed at a low level. An n-side electrode is provided on a surface of the n-type semiconductor layer containing Ga. The electrode includes a metal layer having a Ga content of equal to or more than 1 at % and equal to or less than 25 at %. The metal layer is disposed in contact with the n-type semiconductor layer.

Abstract: A method for manufacturing a high quality optical semiconductor device includes: (a) preparing a growth substrate; (b) forming a semiconductor layer on the growth substrate; (c) forming a metal support made of copper on the semiconductor layer by plating; (d) separating the growth substrate from the semiconductor layer to remove the growth substrate; and (e) carrying out a thermal treatment in order to even density distributions of crystal grains and voids in the copper forming the metal support.

Abstract: A semiconductor laser device includes a substrate and a semiconductor layer formed on a surface of the substrate and having a waveguide extending in a first direction parallel to the surface, wherein the waveguide is formed on a region approaching a first side from a center of the semiconductor laser device in a second direction parallel to the surface and intersecting with the first direction, a first region separated from the waveguide on a side opposite to the first side of the waveguide and extending parallel to the first direction and a first recess portion separated from the waveguide on an extension of a facet of the waveguide, intersecting with the first region and extending in the second direction are formed on an upper surface of the semiconductor laser device, and a thickness of the semiconductor layer on the first region is smaller than a thickness of the semiconductor layer on a region other than the first region.

Abstract: Provided is a method for fabricating a light emitting device. The method for fabricating the light emitting device includes forming a buffer layer including a compound semiconductor in which a rare-earth element is doped on a substrate, forming a light emitting structure including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, which are successively stacked on the buffer layer, forming a first electrode layer on the light emitting structure, removing the substrate, and forming a second electrode layer under the light emitting structure.

Abstract: Provided is a normally-off field effect transistor using a III-nitride semiconductor. The transistor is provided with a III-nitride semiconductor layer grown on a substrate by including an acceptor and a donor; a gate insulating film which is formed on the III-nitride semiconductor layer to have a thickness to be at a prescribed threshold voltage based on the concentration of the acceptor and that of the donor; a gate electrode formed on the gate insulating film; a first source/drain electrode formed on the III-nitride semiconductor layer to one side of and separate from the gate electrode, directly or via a high dopant concentration region; and a second source/drain electrode formed away from the gate electrode and the first source/drain electrode, on or under the III-nitride semiconductor layer, directly or via a high dopant concentration region.

Abstract: A method for fabricating an electrode by (i) depositing a palladium film on a p-type semiconductor layer; (ii) introducing an oxygen gas onto the palladium film to provide an oxygen ambient; (iii) oxidizing the palladium film adjacent to the semiconductor layer by annealing the palladium film in the oxygen ambient; and (iv) forming a palladium oxide film directly in contact with the semiconductor layer.

Abstract: A method for forming an electrode for Group-III nitride compound semiconductor light-emitting devices includes a step of forming a first electrode layer having an average thickness of less than 1 nm on a Group-III nitride compound semiconductor layer, the first electrode layer being made of a material having high adhesion to the Group-III nitride compound semiconductor layer or low contact resistance with the Group-III nitride compound semiconductor layer and also includes a step of forming a second electrode layer made of a highly reflective metal material on the first electrode layer.

Abstract: Methods of forming aluminum oxide layers on substrates are disclosed. In some embodiments, the method includes depositing an aluminum oxide seed layer on the substrate using a first process having a first deposition rate. The method further includes depositing a bulk aluminum oxide layer atop the seed layer using a metalorganic chemical vapor deposition (MOCVD) process having a second deposition rate greater than the first deposition rate.

Abstract: There is provided a technology for obtaining an electrode having a low contact resistance and less surface roughness. There is provided an electrode comprising a semiconductor film 101, and a first metal layer 102 and a second metal layer 103 sequentially stacked in this order on the semiconductor film 101, characterized in that the first metal film 102 is formed of Al, and the second metal film 103 is formed of at least one metal selected from the group consisting of Nb, W, Fe, Hf, Re, Ta and Zr.

Abstract: A semiconductor device includes a p-type nitride semiconductor layer (14); and a p-side electrode (18) including a palladium oxide film (30) connected to a surface of the nitride semiconductor layer (14).

Abstract: The present invention relates to a I?-nitride compound semiconductor light emitting device comprising an active layer with the multi-quantum wells interposed between an n-InxAlyGazN(x+y+z=1, 0<x<1, 0<y<1, 0<z?1) layer and a p-InxAlyGazN(x+y+z=1, 0<x<1, 0<y<1, 0<z<1) layer, wherein the active layer comprises an alternate stacking of a quantum-well layer made of InxGa1-xN(0.05<x<1) and a sandwich barrier layer, the sandwich barrier layer comprising a first outer barrier layer of InaGa1-aN(0<a<0.05), a middle barrier layer of AlyGa1-yN(0<y<1) formed on the first outer barrier layer and a second outer barrier layer of InbGa1-bN(0<b<0.05) formed on the middle barrier layer, thereby a high-efficiency/high-output light emitting device with high-current and high-temperature properties can be obtained, and it is possible to easily achieve a high-efficiency green light emission at a wavelength equal to or over 500 nm, and high-efficiency near UV light emission.

Abstract: Methods are disclosed of fabricating a compound nitride semiconductor structure. A substrate is disposed over a susceptor in a processing chamber, with the susceptor in thermal communication with the substrate. A group-III precursor and a nitrogen precursor are flowed into the processing chamber. The susceptor is heated with a nonuniform temperature profile to heat the substrate. A nitride layer is deposited over the heated substrate with a thermal chemical vapor deposition process within the processing chamber using the group-III precursor and the nitrogen precursor.

Abstract: A method for forming an electrode for Group-III nitride compound semiconductor light-emitting devices includes a step of forming a first electrode layer having an average thickness of less than 1 nm on a Group-III nitride compound semiconductor layer, the first electrode layer being made of a material having high adhesion to the Group-III nitride compound semiconductor layer or low contact resistance with the Group-III nitride compound semiconductor layer and also includes a step of forming a second electrode layer made of a highly reflective metal material on the first electrode layer.

Abstract: An undoped GaN layer having a thickness of 3 ?m is formed by MOVPE on a sapphire substrate with a buffer layer composed of aluminum nitride (AlN) therebetween. A GaN layer doped with 5×1019/cm3 of Mg and having a thickness of 100 nm is formed thereon. An ITO film having a thickness of 300 nm is formed by vacuum evaporation (EB). The wafer is kept in nitrogen at 700° C. for 5 minutes so as to reduce the resistance of the GaN layer doped with 5×1019/cm3 of Mg and having a thickness of 100 nm, so that a p-GaN layer is obtained. A FeCl3 aqueous solution is prepared, and the ITO film is removed. In this manner, a surface of the p-GaN layer having reduced resistance is exposed. The hole concentration is 4.3×1017/cm3. The resistivity is 3.0 ?cm.

Abstract: In another embodiment, the invention provides a compound semiconductor field effect transistor having a fin structure. A first layer is formed on or above a substrate, wherein the first layer contains a first compound semiconductor material. A second layer is formed on the first layer, wherein the second layer comprises a second compound semiconductor material. A third layer is formed on the second layer, wherein the third layer comprises a third compound semiconductor material. A cap layer is formed on at least one partial region of the third layer, wherein the cap layer comprises a fourth compound semiconductor material. The second layer, the third layer and the cap layer are patterned in such a way that a fin structure is formed. A first source/drain region is formed from a first partial region of the cap layer, and a second source/drain region is formed from a second partial region of the cap layer.

Abstract: A nitride semiconductor device is manufactured by the step of forming a nitride semiconductor layer form on a GaN substrate main surface, the step of polishing a back surface of the GaN substrate formed with the above-mentioned nitride semiconductor layer, the step of dry etching the back surface of the GaN substrate subjected to the above-mentioned polishing by using a gas mixture of chlorine and oxygen, and the step of forming an n-type electrode on the back surface of the GaN substrate subjected to the above-mentioned dry etching.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: An electrode forming method with an excellent yield, includes: (a) forming an adhesion preventing member having a predetermined pattern on a base member: (b) forming a conductive layer on the base member and the adhesion preventing member; and (c) forming an electrode having a predetermined pattern by removing the conductive layer on the adhesion preventing member in a state in which the adhesion preventing member is disposed on the base member. Adhesion between the adhesion preventing member and the conductive layer is smaller than adhesion between the base member and the conductive layer.