# US 12,224,332 B2 · Semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,332 B2 - Document ID: US12224332B2 - Status: Granted - Kind: B2 - Application number: 17/657,168 - Filed: 2022-03-30 - Published: 2022-07-14 - Granted: 2025-02-11 - Earliest claimed: 2019-10-02 - Assignees: Japan Display Inc. - Applicants: Japan Display Inc. - Inventors: Akihiro Hanada; Takuo Kaitoh; Hajime Watakabe - Web page: https://patentgrep.com/patent/US12224332B2 ## CPC - H10D 30/6739: {Conductor-insulator-semiconductor electrodes} - G02F 1/1368: in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} - H10D 30/6713: {characterised by the properties of the source or drain regions, e.g. compositions or sectional shapes} - H10D 30/6715: {characterised by the doping profiles, e.g. having lightly-doped source or drain extensions} - H10D 30/673: {characterised by the shapes, relative sizes or dispositions of the gate electrodes} - H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate} - H10D 86/423: {comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO} - H10D 86/60: wherein the TFTs are in active matrices - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract The purpose of the present invention is to suppress a change in characteristics of a TFT using an oxide semiconductor film caused by that oxygen in the oxide semiconductor film is extracted by metal electrode. The main structure of the present invention is as follows. A semiconductor device having a TFT, in which a gate insulating film is formed on a gate electrode, and an oxide semiconductor film is formed on the gate insulating film; the oxide semiconductor film including a channel region, a drain region, and a source region; in which a metal nitride film is formed on a top surface of the gate electrode in an opposing portion to the channel region in a plan view; and the metal nitride film is not formed at a part of the top surface of the gate electrode. ## Claims ### Claim 1 A semiconductor device having a TFT, in which a gate insulating film is formed on a gate electrode, and an oxide semiconductor film is formed on the gate insulating film; the oxide semiconductor film including a channel region, a drain region, and a source region, wherein a metal nitride film is formed on a top surface of the gate electrode in an opposing portion to the channel region in a plan view, the metal nitride film is not formed at a part of the top surface of the gate electrode, the oxide semiconductor film comprises an intermediate resistance region between the channel region and the drain region and between the channel region and the source region of the oxide semiconductor film, the metal nitride film is not formed at places of the top surface of the gate electrode corresponding to the intermediate resistance region, and the metal nitride film is formed at places of the top surface of the gate electrode corresponding to the drain region and the source region of the oxide semiconductor film. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein the metal nitride film is formed on a side surface of the gate electrode. ### Claim 3 (depends on 1) The semiconductor device according to claim 1, wherein the metal nitride film is a titanium nitride (TiN) film. ### Claim 4 (depends on 1) The semiconductor device according to claim 1, wherein the gate electrode is a laminated film of aluminum (Al) layer over coated by titanium (Ti) layer. ### Claim 5 A semiconductor device having a TFT, in which a gate insulating film is formed on a gate electrode, and an oxide semiconductor film is formed on the gate insulating film; the oxide semiconductor film including a channel region, a drain region, and a source region, wherein a metal oxide film is formed on a top surface of the gate electrode in an opposing portion to the channel region in a plan view, the metal oxide film is not formed at a part of the top surface of the gate electrode, the oxide semiconductor film comprises an intermediate resistance region between the channel region and the drain region and between the channel region and the source region of the oxide semiconductor film, the metal oxide film is not formed at places of the top surface of the gate electrode corresponding to the intermediate resistance region, and the metal oxide is formed at places of the top surface of the gate electrode corresponding to the drain region and the source region of the oxide semiconductor film. ### Claim 6 (depends on 5) The semiconductor device according to claim 5, wherein the metal oxide film is formed on a side surface of the gate electrode. ### Claim 7 (depends on 5) The semiconductor device according to claim 5, wherein the metal oxide film is a conductive metal oxide film. ### Claim 8 (depends on 5) The semiconductor device according to claim 5, wherein the metal oxide film is an ITO film. ### Claim 9 (depends on 5) The semiconductor device according to claim 5, wherein the metal oxide film is another oxide semiconductor film formed separately from the oxide semiconductor film. ### Claim 10 A semiconductor device having a TFT, in which a gate insulating film is formed on a gate electrode, and an oxide semiconductor film is formed on the gate insulating film; the oxide semiconductor film including a channel region, a drain region, and a source region, wherein an insulating metal oxide film is formed on a top surface of the gate electrode in an opposing portion to the channel region in a plan view, the metal oxide film is not formed at a part of the top surface of the gate electrode, the oxide semiconductor film comprises an intermediate resistance region between the channel region and the drain region and between the channel region and the source region of the oxide semiconductor film, the insulating metal oxide film is not formed at places of the top surface of the gate electrode corresponding to the intermediate resistance region, and the insulating metal oxide film is formed at places of the top surface of the gate electrode corresponding to the drain region and the source region of the oxide semiconductor film. ### Claim 11 (depends on 10) The semiconductor device according to claim 10, wherein the insulating metal oxide film is formed on a side surface of the gate electrode. ### Claim 12 (depends on 10) The semiconductor device according to claim 10, wherein the metal oxide film is an alumina (AlOx) film.