# US 2014/0197889 A1 · Semiconductor device, method for manufacturing the same, power supply device, and high-frequency amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197889 A1 - Document ID: US20140197889A1 - Status: Published application - Kind: A1 - Application number: 14/088,977 - Filed: 2013-11-25 - Published: 2014-07-17 - Earliest claimed: 2013-01-17 - Assignees: Fujitsu Limited - Applicants: Fujitsu Limited - Inventors: Kozo Makiyama - Web page: https://patentgrep.com/patent/US20140197889A1 ## CPC - H03F 3/16: with field-effect devices - H02M 3/335: using semiconductor devices only - H03F 1/3247: {using feedback acting on predistortion circuits (H03F1/3264 takes precedence)} - 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 64/118: {Electrodes comprising insulating layers having particular dielectric or electrostatic properties, e.g. having static charges} - H10W 74/137: {the encapsulations being directly on the semiconductor body (H10W74/134 takes precedence)} - H10W 74/43: comprising oxides, nitrides or carbides, e.g. ceramics or glasses - H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN} - H10D 64/411: {for FETs} - H03F: AMPLIFIERS - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A semiconductor device includes: a compound semiconductor stack structure including a plurality of compound semiconductor layers stacked over a semiconductor substrate; a first insulating film covering the surface of the compound semiconductor stack structure; and a conductive film provided on the surface of the first insulating film. ## Claims ### Claim 1 A semiconductor device comprising: a compound semiconductor stack structure including a plurality of compound semiconductor layers stacked over a semiconductor substrate; a first insulating film covering the surface of the compound semiconductor stack structure; and a conductive film provided on the surface of the first insulating film. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein the first insulating film is a silicon nitride film; and the conductive film is a conductive silicon nitride film. ### Claim 3 (depends on 1) The semiconductor device according to claim 1, wherein the first insulating film is a stoichiometric silicon nitride film having a refractive index to 633 nm wavelength light of or close to 2.0; and the conductive film is a conductive silicon nitride film having a refractive index to 633 nm wavelength light of not less than 2.3. ### Claim 4 (depends on 1) The semiconductor device according to claim 1, further comprising: a second insulating film covering the first insulating film and the conductive film. ### Claim 5 (depends on 1) The semiconductor device according to claim 1, further comprising: a gate electrode provided over the compound semiconductor stack structure; and a source electrode and a drain electrode provided on both sides with the gate electrode interposed therebetween, wherein the conductive film is provided on the drain electrode side with respect to the gate electrode. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, further comprising: a gate electrode provided over the compound semiconductor stack structure; and a source electrode and a drain electrode provided on both sides with the gate electrode interposed therebetween, wherein the conductive film is provided on both the drain electrode side and the source electrode side with respect to the gate electrode. ### Claim 7 (depends on 1) The semiconductor device according to claim 1, further comprising: a gate electrode provided over the compound semiconductor stack structure; and a source electrode and a drain electrode provided on both sides with the gate electrode interposed therebetween, wherein the first insulating film has a gate electrode formation opening, the gate electrode has a first portion provided in the gate electrode formation opening, and a second portion provided on the first portion so as to extend toward the source electrode and the drain electrode and to be in contact with the surface of the first insulating film; and wherein the conductive film is provided on a region of the surface of the first insulating film excluding the region on which the second portion is disposed and a region in the vicinity of the region on which the second portion is disposed. ### Claim 8 (depends on 1) The semiconductor device according to claim 1, further comprising: a gate electrode provided over the compound semiconductor stack structure; and a source electrode and a drain electrode provided on both sides with the gate electrode interposed therebetween, wherein the first insulating film has a gate electrode formation opening, the gate electrode has a first portion provided in the gate electrode formation opening and extending upward beyond the first insulating film, and a second portion extending over the first portion toward the source electrode and the drain electrode and provided without contact with the surface of the first insulating film, and wherein the conductive film is provided on a region of the surface of the first insulating film including a region found under the second portion. ### Claim 9 A method for manufacturing semiconductor devices, comprising: forming a compound semiconductor stack structure by stacking a plurality of compound semiconductor layers over a semiconductor substrate; forming a first insulating film to cover the surface of the compound semiconductor stack structure; and forming a conductive film on the surface of the first insulating film. ### Claim 10 (depends on 9) The method for manufacturing semiconductor devices according to claim 9, wherein the forming of the first insulating film comprises forming a silicon nitride film while supplying SiH4 as a Si material gas; and the forming of the conductive film comprises forming a conductive silicon nitride film while increasing the flow rate of SiH4 compared to the flow rate during the formation of the first insulating film. ### Claim 11 (depends on 9) The method for manufacturing semiconductor devices according to claim 9, further comprising: forming a second insulating film to cover the first insulating film and the conductive film. ### Claim 12 A power supply device comprising: a transformer; and a high-voltage circuit and a low-voltage circuit disposed with the transformer interposed therebetween, the high-voltage circuit comprising a transistor, the transistor including: a compound semiconductor stack structure including a plurality of compound semiconductor layers stacked over a semiconductor substrate, a first insulating film covering the surface of the compound semiconductor stack structure, and a conductive film provided on the surface of the first insulating film. ### Claim 13 A high-frequency amplifier comprising: an amplifier configured to amplify an input signal, the amplifier comprising a transistor, the transistor including: a compound semiconductor stack structure including a plurality of compound semiconductor layers stacked over a semiconductor substrate, a first insulating film covering the surface of the compound semiconductor stack structure, and a conductive film provided on the surface of the first insulating film.