# US 10,373,980 B2 · Method of manufacturing semiconductor device including pixel electrode containing indium, zinc, and metal element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,980 B2 - Document ID: US10373980B2 - Status: Granted - Kind: B2 - Application number: 15/494,833 - Filed: 2017-04-24 - Published: 2017-08-10 - Granted: 2019-08-06 - Earliest claimed: 2013-05-10 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Hiroyuki Miyake; Shunpei Yamazaki - Web page: https://patentgrep.com/patent/US10373980B2 ## CPC - H10D 86/60: wherein the TFTs are in active matrices - G02F 1/133345: {Insulating layers (G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence)} - G02F 1/13439: {characterised by their electrical, optical, physical properties; materials therefor; method of making} - G02F 1/136213: {Storage capacitors associated with the pixel electrode} - G02F 1/1368: in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} - 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 86/451: {characterised by the compositions or shapes of the interlayer dielectrics} - H10D 86/481: {integrated with passive devices, e.g. auxiliary capacitors} - G02F 2201/123: pixel - G02F 2202/10: semiconductor - H10K 59/1213: {the pixel elements being TFTs} - H10K 59/1216: {the pixel elements being capacitors} - H10K 59/123: Connection of the pixel electrodes to the thin film transistors [TFT] - 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 - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract To provide a display device including a transistor that includes an oxide semiconductor and has favorable characteristics, a pixel electrode electrically connected to the transistor, and a capacitor electrically connected to the pixel electrode. To provide a display device that can be manufactured at low cost. The display device includes a display element including a pixel electrode, a transistor that performs switching of the display element and includes a first oxide semiconductor layer serving as a channel formation region, a capacitor that is electrically connected to the display element and includes a dielectric layer between a pair of electrodes. The pixel electrode is a second oxide semiconductor layer formed on the same surface as that on which the first oxide semiconductor layer is formed, and also serves as one electrode of the capacitor. ## Claims ### Claim 1 A method for forming a display device comprising the steps of: forming a conductive layer over a substrate; forming a first electrode and a second electrode by patterning the conductive layer; forming a first insulating layer covering the first electrode and the second electrode; forming an oxide semiconductor layer over the first insulating layer; forming a first oxide semiconductor layer overlapping with the first electrode and a second oxide semiconductor layer overlapping with the second electrode by patterning the oxide semiconductor layer; forming a source electrode and a drain electrode over and in contact with the first oxide semiconductor layer; forming an oxide insulating layer over and in contact with the first oxide semiconductor layer, the source electrode, and the drain electrode; forming a first opening in the oxide insulating layer, the first opening overlaps with the second oxide semiconductor layer and the second electrode; and forming a pixel electrode from the second oxide semiconductor layer, wherein the step of forming the pixel electrode comprises a step of: forming a second insulating layer containing hydrogen over and in contact with the second oxide semiconductor layer in the first opening, wherein the first oxide semiconductor layer serves as a channel formation region, wherein the second electrode, a portion of the first insulating layer, and a portion of the pixel electrode form a capacitor, wherein the oxide semiconductor layer contains indium, zinc, and a metal element, and wherein the step of forming the pixel electrode further comprises a step of: removing a part of the second insulating layer overlapped with the first opening after the second insulating layer is in contact with the second oxide semiconductor layer. ### Claim 2 (depends on 1) The method for forming the display device according to claim 1, wherein the metal element is any one of Al, Ti, Ga, Y, Zr, La, Ce, Nd, and Hf. ### Claim 3 (depends on 1) The method for forming the display device, according to claim 1, wherein the second insulating layer is a silicon nitride layer with a hydrogen concentration of 1×1022 atoms/cm3 or higher. ### Claim 4 (depends on 1) The method for forming the display device, according to claim 1, further comprising a step of: performing first heat treatment on the first oxide semiconductor layer and the second oxide semiconductor layer; and performing second heat treatment after forming the oxide insulating layer. ### Claim 5 (depends on 1) The method for forming the display device according to claim 1, wherein an amount of oxygen vacancies of the first oxide semiconductor layer is lower than an amount of oxygen vacancies of the pixel electrode. ### Claim 6 (depends on 1) The method for forming the display device according to claim 1, wherein a resistivity of the pixel electrode is lower than a resistivity of the first oxide semiconductor layer. ### Claim 7 A method for forming a display device comprising the steps of: forming a conductive layer over a substrate; forming a first electrode and a second electrode by patterning the conductive layer; forming a first insulating layer covering the first electrode and the second electrode; forming an oxide semiconductor layer over the first insulating layer; forming a first oxide semiconductor layer overlapping with the first electrode and a second oxide semiconductor layer overlapping with the second electrode by patterning the oxide semiconductor layer; forming a source electrode and a drain electrode over and in contact with the first oxide semiconductor layer; forming an oxide insulating layer over and in contact with the first oxide semiconductor layer, the source electrode, and the drain electrode; forming a first opening in the oxide insulating layer, the first opening overlaps with the second oxide semiconductor layer and the second electrode; forming a pixel electrode from the second oxide semiconductor layer; wherein the step of forming the pixel electrode comprises a step of: forming a second insulating layer containing hydrogen over and in contact with the second oxide semiconductor layer in the first opening, and forming a liquid crystal layer over the pixel electrode, wherein the first oxide semiconductor layer serves as a channel formation region, wherein the second electrode, a portion of the first insulating layer, and a portion of the pixel electrode form a capacitor, wherein the oxide semiconductor layer contains indium, zinc, and a metal element, and wherein the step of forming the pixel electrode further comprises a step of: removing a part of the second insulating layer overlapped with the first opening after the second insulating layer is in contact with the second oxide semiconductor layer. ### Claim 8 (depends on 7) The method for forming the display device according to claim 7, wherein the metal element is any one of Al, Ti, Ga, Y, Zr, La, Ce, Nd, and Hf. ### Claim 9 (depends on 7) The method for forming the display device, according to claim 7, wherein the second insulating layer is a silicon nitride layer with a hydrogen concentration of 1×1022 atoms/cm3 or higher. ### Claim 10 (depends on 7) The method for forming the display device, according to claim 7, further comprising a step of: performing first heat treatment on the first oxide semiconductor layer and the second oxide semiconductor layer; and performing second heat treatment after forming the oxide insulating layer. ### Claim 11 (depends on 7) The method for forming the display device according to claim 7, wherein an amount of oxygen vacancies of the first oxide semiconductor layer is lower than an amount of oxygen vacancies of the pixel electrode. ### Claim 12 (depends on 7) The method for forming the display device according to claim 7, wherein a resistivity of the pixel electrode is lower than a resistivity of the first oxide semiconductor layer. ### Claim 13 (depends on 1) The method for forming the display device, according to claim 1, wherein the second insulating layer is a silicon nitride layer, and wherein the oxide insulating layer is covered with the silicon nitride layer. ### Claim 14 (depends on 7) The method for forming the display device, according to claim 7, wherein the second insulating layer is a silicon nitride layer, and wherein the oxide insulating layer is covered with the silicon nitride layer.