# US 8,772,771 B2 · Method for manufacturing semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,771 B2 - Document ID: US8772771B2 - Status: Granted - Kind: B2 - Application number: 13/870,370 - Filed: 2013-04-25 - Published: 2013-10-31 - Granted: 2014-07-08 - Earliest claimed: 2012-04-30 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Tetsuhiro Tanaka - Web page: https://patentgrep.com/patent/US8772771B2 ## CPC - H10D 30/031: {of thin-film transistors [TFT]} - H10D 30/0318: {of vertical TFTs} - H10D 30/6728: {Vertical TFTs} - 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 ## Abstract Miniaturized transistors having high and stable electric characteristics using high precision microfabrication are provided with high yield. Further, high performance, high reliability, and high productivity also of a semiconductor device including the transistor are achieved. A semiconductor device includes a vertical transistor in which a first electrode layer, a first oxide film containing indium, gallium, zinc, and nitrogen as main components, an oxide semiconductor film containing indium, gallium, and zinc as main components, a second oxide film containing indium, gallium, zinc, and nitrogen as main components, and a second electrode layer are stacked in this order, and a first gate insulating film and a first gate electrode layer are provided at one side of the columnar oxide semiconductor film and a second gate insulating film and a second gate electrode layer are provided at the other side of the columnar oxide semiconductor film. ## Claims ### Claim 1 A method for manufacturing a semiconductor device, comprising the steps of: forming a first electrode layer; forming a first oxide film over the first electrode layer; forming an oxide semiconductor film over the first oxide film; forming a second oxide film over the oxide semiconductor film; etching the oxide semiconductor film and the second oxide film to form a column object of the oxide semiconductor film and the second oxide film over the first oxide film; forming an insulating film over the column object; forming an island-shaped conductive film over the insulating film; anisotropically etching the insulating film and the island-shaped conductive film to form a gate insulating film and a gate electrode layer, and to expose the second oxide film of the column object; and forming a second electrode layer electrically connected to the second oxide film of the column object. ### Claim 2 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein a mixed solution of acetic acid, nitric acid, and phosphoric acid is used in the step of etching the oxide semiconductor film and the second oxide film to form the column object, and wherein the second oxide film is used as a mask while being receded in a line width direction in the step of etching the oxide semiconductor film and the second oxide film to form the column object. ### Claim 3 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein a part of the first oxide film is etched in the step of anisotropically etching the oxide semiconductor film and the second oxide film. ### Claim 4 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein an interlayer insulating film is formed over the first oxide film, the column object, the gate insulating film, and the gate electrode layer, wherein the second oxide film of the column object is exposed by removing the interlayer insulating film, and wherein the second electrode layer is formed in contact with the exposed second oxide film. ### Claim 5 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein the first oxide film and the second oxide film have a higher resistance property to etching using the mixed solution of acetic acid, nitric acid, and phosphoric acid and an etching speed is later than the oxide semiconductor film. ### Claim 6 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein the first oxide film and the second oxide film have lower resistance than the oxide semiconductor film, wherein the oxide semiconductor film functions as a channel formation region, and wherein the first oxide film and the second oxide film function as a source region and a drain region. ### Claim 7 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, further comprising the steps of: anisotropically etching the oxide semiconductor film and the second oxide film by using a resist mask before etching the oxide semiconductor film and the second oxide film to form the column object. ### Claim 8 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein the second oxide film is formed by a sputtering method in which a target containing indium, gallium, zinc, and nitrogen as main components is used. ### Claim 9 (depends on 1) The method for manufacturing the semiconductor device according to claim 1, wherein the second oxide film is formed by forming an oxide film containing indium, gallium, and zinc as main components and introducing nitrogen to the oxide film. ### Claim 10 A method for manufacturing a semiconductor device, comprising the steps of: forming a first electrode layer; stacking a first oxide film containing indium, gallium, zinc, and nitrogen as main components, an oxide semiconductor film containing indium, gallium, and zinc as main components, and a second oxide film containing indium, gallium, zinc, and nitrogen as main components in this order; forming a column object of the oxide semiconductor film and the second oxide film by etching the oxide semiconductor film in an etching step using a mixed solution of acetic acid, nitric acid, and phosphoric acid using the second oxide film as a mask while being receded in a line width direction, the column object standing over the first oxide film; forming a gate insulating film covering at least a side of the oxide semiconductor film of the column object and a first gate electrode layer and a second gate electrode layer which overlap with the oxide semiconductor film of the column object with the gate insulating film provided between the oxide semiconductor film and the first gate electrode layer and between the oxide semiconductor film and the second gate electrode layer and facing each other by stacking an insulating film and an island-shaped conductive film over the column object and anisotropically etching the insulating film and the island-shaped conductive film; and forming a second electrode layer electrically connected to the second oxide film of the column object. ### Claim 11 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein an interlayer insulating film is formed over the first electrode layer, the first oxide film, the column object, the gate insulating film, the first gate electrode layer, and the second gate electrode layer, wherein the second oxide film of the column object is exposed by selectively removing the interlayer insulating film, and wherein the second electrode layer is formed in contact with the exposed second oxide film. ### Claim 12 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein the first oxide film and the second oxide film have a higher resistance property to etching using the mixed solution of acetic acid, nitric acid, and phosphoric acid and an etching speed is later than the oxide semiconductor film. ### Claim 13 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein the first oxide film and the second oxide film have lower resistance than the oxide semiconductor film, wherein the oxide semiconductor film functions as a channel formation region, and wherein the first oxide film and the second oxide film function as a source region and a drain region. ### Claim 14 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein a resist mask is formed over the oxide semiconductor film and the second oxide film before the etching step and the oxide semiconductor film and the second oxide film are each processed into an island shape through an anisotropic etching step using the resist mask. ### Claim 15 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein the second oxide film is formed by a sputtering method in which a target containing indium, gallium, zinc, and nitrogen as main components is used. ### Claim 16 (depends on 10) The method for manufacturing the semiconductor device according to claim 10, wherein the second oxide film is formed by forming an oxide film containing indium, gallium, and zinc as main components and introducing nitrogen to the oxide film. ### Claim 17 A semiconductor device comprising: a first electrode layer; a first oxide film over the first electrode layer; an oxide semiconductor film over the first oxide film; a second oxide film over the oxide semiconductor film; a gate insulating film and a gate electrode layer covering a side surface of the oxide semiconductor film wherein the gate insulating film is between the oxide semiconductor film and the gate electrode layer; and a second electrode layer over the second oxide film. wherein the first oxide film contains indium, gallium, zinc, and nitrogen as main components, wherein the oxide semiconductor film contains indium, gallium, and zinc as main components, and wherein the second oxide film contains indium, gallium, zinc, and nitrogen as main components. ### Claim 18 (depends on 17) The semiconductor device according to claim 17, wherein an interlayer insulating film is between the first electrode layer and the second electrode layer. ### Claim 19 (depends on 17) The semiconductor device according to claim 17, wherein the first oxide film and the second oxide film have lower resistance than the oxide semiconductor film, wherein the oxide semiconductor film functions as a channel formation region, and wherein the first oxide film and the second oxide film function as a source region and a drain region.