# US 12,191,383 B2 · Semiconductor device with an insulating region formed between a control electrode and a conductive element and method of fabrication therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,383 B2 - Document ID: US12191383B2 - Status: Granted - Kind: B2 - Application number: 17/561,796 - Filed: 2021-12-24 - Published: 2023-06-29 - Granted: 2025-01-07 - Earliest claimed: 2021-12-24 - Assignees: NXP USA, Inc. - Applicants: NXP USA, Inc. - Inventors: Bruce Mcrae Green; Ibrahim Khalil; Bernhard Grote - Web page: https://patentgrep.com/patent/US12191383B2 ## CPC - 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 30/015: {of FETs having heterojunction interface channels or heterojunction gate electrodes, e.g. HEMT} - H10D 64/111: {Field plates} - H10D 62/149: {Source or drain regions of field-effect devices} - H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN} - H10D 64/411: {for FETs} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract An embodiment of a semiconductor device includes a semiconductor substrate, a first dielectric layer, a first current-carrying electrode, and a second current-carrying electrode formed over the semiconductor substrate. A control electrode is formed over the semiconductor substrate and disposed between the first current-carrying electrode and the second current-carrying electrode. A conductive element formed over the first dielectric layer, adjacent the control electrode, and between the control electrode and the second current-carrying electrode, includes a first region formed a first distance from the upper surface of the semiconductor substrate and a second region formed a second distance from the upper surface of the semiconductor substrate. An insulating region is formed between the control electrode and the conductive element. ## Claims ### Claim 1 A semiconductor device comprising: a semiconductor substrate comprising an upper surface and a channel; a first dielectric layer disposed over the upper surface of the semiconductor substrate; a first current-carrying electrode and a second current-carrying electrode formed over the semiconductor substrate, wherein the first current-carrying electrode and the second current-carrying electrode are electrically coupled to the channel; a control electrode formed over the semiconductor substrate and disposed between the first current-carrying electrode and the second current-carrying electrode, wherein the control electrode is electrically coupled to the channel, and wherein the control electrode includes a first sidewall portion nearer the first current-carrying electrode that extends upward from the first dielectric layer, and the control electrode includes a second sidewall portion nearer the second current-carrying electrode that extends upward from the first dielectric layer; a conductive element, formed over the first dielectric layer, adjacent the control electrode, and between the control electrode and the second current-carrying electrode, wherein the conductive element further comprises a first region formed directly on the first dielectric layer at a first distance from the upper surface of the semiconductor substrate and a second region formed over the first dielectric layer at a second distance from the upper surface of the semiconductor substrate, and wherein the second distance is greater than the first distance; and an insulating region formed adjacent the control electrode, wherein the insulating region includes a first portion formed laterally adjacent the first sidewall portion of the control electrode, nearer the first current-carrying electrode, and a second portion formed laterally adjacent the second sidewall portion of the control electrode, nearer the second current-carrying electrode, wherein the first portion and the second portion are formed over the first dielectric layer, and wherein the second portion is formed between the control electrode and the conductive element. ### Claim 2 (depends on 1) The semiconductor device of claim 1, wherein a portion of the conductive element is formed above a portion of the control electrode. ### Claim 3 (depends on 1) The semiconductor device of claim 1, wherein the semiconductor substrate includes a group-III nitride layer. ### Claim 4 (depends on 1) The semiconductor device of claim 1, wherein the first dielectric layer includes silicon nitride and the first portion and the second portion include a material selected from the group consisting of silicon dioxide and tetraethyl orthosilicate. ### Claim 5 (depends on 1) The semiconductor device of claim 1, further comprising a first etch stop layer formed over the first dielectric layer, the control electrode, and between the control electrode and the first portion and the second portion. ### Claim 6 A semiconductor device comprising: a semiconductor substrate comprising an upper surface and a channel; a first dielectric layer disposed over the upper surface of the semiconductor substrate; a first current-carrying electrode and a second current-carrying electrode formed over the semiconductor substrate, wherein the first current-carrying electrode and the second current-carrying electrode are electrically coupled to the channel; a control electrode formed over the semiconductor substrate and disposed between the first current-carrying electrode and the second current-carrying electrode, wherein the control electrode is electrically coupled to the channel; a conductive element, formed over the first dielectric layer, adjacent the control electrode, and between the control electrode and the second current-carrying electrode, wherein the conductive element further comprises a first region formed a first distance from the upper surface of the semiconductor substrate and a second region formed a second distance from the upper surface of the semiconductor substrate; an insulating region formed adjacent the control electrode, wherein the insulating region includes a first portion formed laterally adjacent a first sidewall portion of the control electrode, nearer the first current-carrying electrode, and a second portion formed laterally adjacent a second sidewall portion of the control electrode, nearer the second current-carrying electrode, wherein the first portion and the second portion are formed over the first dielectric layer, and wherein the second portion is formed between the control electrode and the conductive element; a first etch stop layer formed over the first dielectric layer, the control electrode, and between the control electrode and the first portion and the second portion; and a second etch stop layer formed over the first etch stop layer and over the first portion and the second portion. ### Claim 7 (depends on 6) The semiconductor device of claim 6, further comprising a second dielectric layer formed over the second etch stop layer and over the control electrode. ### Claim 8 (depends on 7) The semiconductor device of claim 7, further comprising a conductive element opening formed in the second dielectric layer over a portion of the first dielectric layer and over a portion of the insulating region, wherein at least a portion the conductive element is formed within the conductive element opening. ### Claim 9 (depends on 8) The semiconductor device of claim 8, wherein an inside spacer layer is formed on a sidewall of the conductive element opening. ### Claim 10 (depends on 1) The semiconductor device of claim 1, wherein the first current-carrying electrode is configured as a source electrode, the second current-carrying electrode is configured as a drain electrode, the control electrode is configured as a gate electrode, and the conductive element is configured as a field plate. ### Claim 11 A gallium nitride field effect transistor device comprising: a semiconductor substrate, comprising gallium nitride and further comprising an upper surface and a channel; a first dielectric layer disposed over the upper surface of the semiconductor substrate; a source electrode and a drain electrode formed over the semiconductor substrate, wherein the source electrode and the drain electrode are electrically coupled to the channel; a gate electrode formed over the semiconductor substrate and disposed between the source electrode and the drain electrode, wherein the gate electrode is electrically coupled to the channel, and wherein the gate electrode includes a first sidewall portion nearer the source electrode that extends upward from the first dielectric layer, and the gate electrode includes a second sidewall portion nearer the drain electrode that extends upward from the first dielectric layer; a field plate, formed over the first dielectric layer, adjacent the gate electrode, and between the gate electrode and the drain electrode, wherein the field plate further comprises a first region formed directly on the first dielectric layer at a first distance from the upper surface of the semiconductor substrate, and a second region formed over the first dielectric layer at a second distance from the upper surface of the semiconductor substrate, wherein the first region, the first dielectric layer, and the semiconductor substrate form portions of a first metal-insulator semiconductor region, the second region, the first dielectric layer, and the semiconductor substrate form portions of a second metal-insulating semiconductor region, and the second distance is greater than the first distance; and a spacer region formed over the first dielectric layer adjacent the gate electrode, wherein the spacer region includes a first portion formed laterally adjacent the first sidewall portion of the gate electrode nearer the source electrode and a second portion formed laterally adjacent the second sidewall portion of the gate electrode, nearer the drain electrode. ### Claim 12 (depends on 11) The gallium nitride field effect transistor device of claim 11, wherein the first portion and the second portion are formed over the first dielectric layer, and wherein the second portion is formed between the gate electrode and the field plate. ### Claim 13 A gallium nitride field effect transistor device comprising: a semiconductor substrate, comprising gallium nitride and further comprising an upper surface and a channel; a first dielectric layer disposed over the upper surface of the semiconductor substrate; a source electrode and a drain electrode formed over the semiconductor substrate, wherein the source electrode and the drain electrode are electrically coupled to the channel; a gate electrode formed over the semiconductor substrate and disposed between the source electrode and the drain electrode, wherein the gate electrode is electrically coupled to the channel; a field plate, formed over the first dielectric layer, adjacent the gate electrode, and between the gate electrode and the drain electrode, wherein the field plate further comprises a first region formed a first distance from the upper surface of the semiconductor substrate, forming a first metal-insulator semiconductor region, and a second region formed a second distance from the upper surface of the semiconductor substrate, forming a second metal-insulating semiconductor region; a spacer region formed adjacent the gate electrode, wherein the spacer region includes a first portion formed laterally adjacent a first sidewall portion of the gate electrode nearer the source electrode and a second portion formed laterally adjacent a second sidewall portion of the gate electrode, nearer the drain electrode, wherein the first portion and the second portion are formed over the first dielectric layer, and wherein the second portion is formed between the gate electrode and the field plate; a first etch stop layer formed over the first dielectric layer and the gate electrode, and between the gate electrode and the spacer region; and a second etch stop layer formed over the first etch stop layer and over the spacer region. ### Claim 14 (depends on 13) The semiconductor device of claim 13, further comprising: a second dielectric layer formed over the second etch stop layer and over the gate electrode; and a field plate opening formed in the second dielectric layer, wherein at least a portion the field plate is formed within the field plate opening. ### Claim 15 (depends on 14) The semiconductor device of claim 14, wherein an inside spacer region is formed on a sidewall of the field plate opening and over at least a portion of the spacer region. ### Claim 16 A method for forming a gallium nitride field effect transistor device comprising: forming a semiconductor substrate, comprising gallium nitride and further comprising an upper surface and a channel; forming a first dielectric layer over the upper surface of the semiconductor substrate; forming a source electrode and a drain electrode over the semiconductor substrate, wherein the source electrode and the drain electrode are electrically coupled to the channel; forming a gate electrode over the semiconductor substrate between the source electrode and the drain electrode, wherein the gate electrode is electrically coupled to the channel, and wherein the gate electrode includes a first sidewall portion nearer the source electrode that extends upward from the first dielectric layer, and the gate electrode includes a second sidewall portion nearer the drain electrode that extends upward from the first dielectric layer; forming a field plate over the first dielectric layer, adjacent the gate electrode, and between the gate electrode and the drain electrode, wherein forming the field plate further comprises: forming a first region directly on the first dielectric layer, parallel to the upper surface and a first distance from the upper surface of the semiconductor substrate, wherein the first region, the first dielectric layer, and the semiconductor substrate form portions of a first metal-insulator semiconductor region; and forming a second region, parallel to the upper surface and a second distance from the upper surface of the semiconductor substrate, wherein the second region, the first dielectric layer, and the semiconductor substrate form portions of a second metal-insulating semiconductor region, and wherein the second distance is greater than the first distance; and forming a spacer region adjacent the gate electrode, wherein forming the spacer region includes a first portion formed laterally adjacent the first sidewall portion of the gate electrode nearer the source electrode and forming a second portion laterally adjacent the second sidewall portion of the gate electrode, nearer the drain electrode. ### Claim 17 (depends on 16) The method of claim 16, wherein the forming the first portion and the second portion includes anisotropically etching a blanket dielectric layer. ### Claim 18 (depends on 17) The method of claim 17, further comprising: forming a first etch stop layer over the first dielectric layer and the gate electrode, and between the gate electrode and the second portion; and forming a second etch stop layer over the first etch stop layer and over the first portion and the second portion. ### Claim 19 (depends on 18) The semiconductor device of claim 18, further comprising: forming a second dielectric layer over the second etch stop layer and over the gate electrode; and forming a field plate opening in the second dielectric layer, wherein at least a portion the field plate is formed within the field plate opening. ### Claim 20 (depends on 19) The semiconductor device of claim 19, further comprising forming an inside spacer layer on a sidewall of the field plate opening and over at least a portion of the spacer region.