# US 10,312,344 B2 · Semiconductor device, manufacturing method of semiconductor device, power unit, and amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,344 B2 - Document ID: US10312344B2 - Status: Granted - Kind: B2 - Application number: 15/652,951 - Filed: 2017-07-18 - Published: 2018-03-29 - Granted: 2019-06-04 - Earliest claimed: 2016-09-28 - Assignees: Fujitsu Limited - Applicants: Fujitsu Limited - Inventors: Shirou Ozaki - Web page: https://patentgrep.com/patent/US10312344B2 ## CPC - H10D 30/021: {of FETs having insulated gates [IGFET]} - H10D 30/015: {of FETs having heterojunction interface channels or heterojunction gate electrodes, e.g. HEMT} - H10D 30/475: {having wider bandgap layer formed on top of lower bandgap active layer, e.g. undoped barrier HEMTs such as i-AlGaN/GaN HEMTs} - H10D 30/4755: {having wide bandgap charge-carrier supplying layers, e.g. modulation doped HEMTs such as n-AlGaAs/GaAs HEMTs} - H10D 62/824: comprising only Group III-V materials heterojunctions, e.g. GaN/AlGaN heterojunctions - H10D 64/01358: {the insulator being formed after the semiconductor body, the semiconductor being a Group III-V material} - H10D 64/254: {for lateral devices wherein the source or drain electrodes extend entirely through the semiconductor bodies, e.g. via-holes for back side contacts} - H10P 14/6312: {of Group III-V semiconductors} - H10P 50/646: {of Group III-V materials} - H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN} - H10D 64/256: {for lateral devices wherein the source or drain electrodes are recessed in semiconductor bodies (source or drain electrodes of TFTs H10D30/673)} - H10D 64/518: {characterised by their lengths or sectional shapes} - H10D 64/685: {being perpendicular to the channel plane} - H10D 64/691: {comprising metallic compounds, e.g. metal oxides or metal silicates (insulators comprising nitrogen H10D64/693)} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A semiconductor device includes a first semiconductor layer formed of a compound semiconductor, provided over a substrate; a second semiconductor layer formed of a compound semiconductor including In and Al, provided over the first semiconductor layer; source and drain electrodes provided on the second semiconductor layer; and a gate electrode provided between the source and drain electrodes, on the second semiconductor layer. The compound semiconductor in the second semiconductor layer has a first In composition ratio in a region on a side facing the substrate and a second In composition ratio in a region on an opposite side, the second In composition ratio being lower than the first In composition ratio, and the source and drain electrodes are provided in contact with the region having the first In composition ratio, and the gate electrode is provided on the region having the second In composition ratio. ## Claims ### Claim 1 A semiconductor device comprising: a first semiconductor layer formed of a compound semiconductor, provided over a substrate; a second semiconductor layer formed of a compound semiconductor including In and Al, provided over the first semiconductor layer; a source electrode and a drain electrode provided on the second semiconductor layer; and a gate electrode provided between the source electrode and the drain electrode, on the second semiconductor layer, wherein the compound semiconductor in the second semiconductor layer has a first In composition ratio in a region of the second semiconductor layer on a side facing the substrate and a second In composition ratio in a region of the second semiconductor layer on a side opposite to the side facing the substrate, the second In composition ratio being a lower In composition ratio than the first In composition ratio, the source electrode and the drain electrode are provided in contact with the region having the first In composition ratio, and the gate electrode is provided on the region having the second In composition ratio, the first semiconductor layer and the second semiconductor layer are formed of a nitride semiconductor, and an N composition ratio in the region having the second In composition ratio is higher than an N composition ratio in the region having the first In composition ratio. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein an Al composition ratio in the region having the second In composition ratio is higher than an Al composition ratio in the region having the first In composition ratio. ### Claim 3 (depends on 1) The semiconductor device according to claim 1, wherein an insulating film is formed on the region having the second In composition ratio in the second semiconductor layer between the source electrode and the drain electrode, and the gate electrode is formed on the insulating film. ### Claim 4 (depends on 3) The semiconductor device according to claim 3, wherein the insulating film is formed of a material including aluminum oxide. ### Claim 5 (depends on 1) The semiconductor device according to claim 1, wherein the second semiconductor layer is formed of a material including InAlN or InAlGaN. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, wherein the first semiconductor layer is formed of a material including GaN. ### Claim 7 (depends on 1) A power supply device comprising the semiconductor device according to claim 1. ### Claim 8 (depends on 1) An amplifier comprising the semiconductor device according to claim 1. ### Claim 9 A semiconductor device comprising: a first semiconductor layer formed of a compound semiconductor, provided over a substrate; a second semiconductor layer formed of a compound semiconductor including In and Al, provided over the first semiconductor layer; a source electrode and a drain electrode formed in contact with the second semiconductor layer; an oxide film formed on the second semiconductor layer between the source electrode and the drain electrode; and a gate electrode formed on the oxide film, wherein the oxide film includes aluminum oxide, the compound semiconductor in the second semiconductor layer has a first In composition ratio in a region of the second semiconductor layer on a side facing the substrate and a second In composition ratio in a region of the second semiconductor layer on a side opposite to the side facing the substrate, the second In composition ratio being a lower In composition ratio than the first In composition ratio, the first semiconductor layer and the second semiconductor layer are formed of a nitride semiconductor, and an N composition ratio in the region having the second In composition ratio is higher than an N composition ratio in the region having the first In composition ratio. ### Claim 10 (depends on 9) The semiconductor device according to claim 9, wherein an insulating film is formed on the oxide film, and the gate electrode is formed on the insulating film.