# US 7,611,930 B2 · Method of manufacturing display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,611,930 B2 - Document ID: US7611930B2 - Status: Granted - Kind: B2 - Application number: 12/186,001 - Filed: 2008-08-05 - Published: 2009-02-19 - Granted: 2009-11-03 - Earliest claimed: 2008-08-05 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Shunpei Yamazaki; Sachiaki Teduka; Makoto Furuno; Satoshi Toriumi; Yasuhiro Jinbo; Koji Dairiki - Web page: https://patentgrep.com/patent/US7611930B2 ## CPC - H10D 62/40: Crystalline structures - H10D 30/0316: {of lateral bottom-gate TFTs comprising only a single gate} - H10D 30/0321: {comprising silicon, e.g. amorphous silicon or polysilicon} - H10D 30/6757: {characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715)} - H10D 86/0221: {comprising manufacture, treatment or patterning of TFT semiconductor bodies} - H10D 86/421: {having a particular composition, shape or crystalline structure of the active layer} - H10D 86/60: wherein the TFTs are in active matrices - H10D 30/6729: {characterised by the electrodes} - H10P 14/24: using chemical vapour deposition [CVD] - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract In a case of forming a bottom-gate thin film transistor, a step of forming a microcrystalline semiconductor film over a gate insulating film by a plasma CVD method, and a step of forming an amorphous semiconductor film over the microcrystalline semiconductor film are performed. In the step of forming the microcrystalline semiconductor film, the pressure in the reaction chamber is set at or below 10−5 Pa once, the substrate temperature is set in the range of 120° C. to 220° C., plasma is generated by introducing hydrogen and a silicon gas, hydrogen plasma is made to act on a reaction product formed on a surface of the gate insulating film to perform removal while performing film formation. Moreover, the plasma is generated by applying a first high-frequency electric power of an HF band a second high-frequency electric power of a VHF band superimposed on each other. ## Claims ### Claim 1 A method of manufacturing a display device, comprising: forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming a microcrystalline semiconductor film over the gate insulating film by a plasma CVD method; and forming an amorphous semiconductor film over the microcrystalline semiconductor film, wherein the step of forming the microcrystalline semiconductor film comprises: a pressure of a reaction chamber being set at or below 10−5 Pa; a temperature of the substrate being set in a range of 100° C. to 200° C.; plasma being produced by introducing hydrogen and a rare gas; and hydrogen plasma being made to act on a reaction product formed on a surface of the gate insulating film to etch the reaction product while forming the microcrystalline semiconductor film. ### Claim 2 (depends on 1) The method of manufacturing a display device according to claim 1, wherein the microcrystalline semiconductor film has an oxygen concentration of 1×1017 atoms/cm3 or less. ### Claim 3 (depends on 1) The method of manufacturing a display device according to claim 1, wherein trimethylboron is introduced in the microcrystalline semiconductor film so that an i-type or p-type microcrystalline semiconductor film is formed. ### Claim 4 (depends on 1) The method of manufacturing a display device according to claim 1, wherein the amorphous semiconductor film is formed over the microcrystalline semiconductor film without exposure of a surface of the microcrystalline semiconductor film to the air. ### Claim 5 A method of manufacturing a display device, comprising: forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming a microcrystalline semiconductor film over the gate insulating film by a plasma CVD method; and forming an amorphous semiconductor film over the microcrystalline semiconductor film, wherein the step of forming the microcrystalline semiconductor film comprises: a pressure of a reaction chamber being set at or below 10−5 Pa; a temperature of the substrate being set in a range of 100° C. to 200° C.; plasma being produced by introducing hydrogen and a rare gas; and hydrogen plasma and rare gas plasma are made to act on a reaction product formed on a surface of the gate insulating film to etch the reaction product while forming the microcrystalline semiconductor film by introducing a silicon gas. ### Claim 6 (depends on 5) The method of manufacturing a display device according to claim 5, wherein the microcrystalline semiconductor film has an oxygen concentration of 1×1017 atoms/cm3 or less. ### Claim 7 (depends on 5) The method of manufacturing a display device according to claim 5, wherein trimethylboron is introduced in the microcrystalline semiconductor film so that an i-type or p-type microcrystalline semiconductor film is formed. ### Claim 8 (depends on 5) The method of manufacturing a display device according to claim 5, wherein the amorphous semiconductor film is formed over the microcrystalline semiconductor film without exposure of a surface of the microcrystalline semiconductor film to the air. ### Claim 9 (depends on 5) The method of manufacturing a display device according to claim 5, wherein the introduction of the rare gas is stopped before the introduction of the silicon gas. ### Claim 10 (depends on 5) The method of manufacturing a display device according to claim 5, wherein the introduction of the rare gas is stopped after the introduction of the silicon gas, wherein a predetermined period is interposed between the introduction of the silicon gas and the stop of the rare gas. ### Claim 11 (depends on 5) The method of manufacturing a display device according to claim 5, wherein argon is used as the rare gas. ### Claim 12 A method of manufacturing a display device, comprising: forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming a microcrystalline semiconductor film over the gate insulating film by a plasma CVD method; and forming an amorphous semiconductor film over the microcrystalline semiconductor film, wherein the step of forming the microcrystalline semiconductor film comprises: a pressure of a reaction chamber being set at or below 10−5 Pa; a temperature of the substrate being set in a range of 100° C. to 200° C.; plasma being generated by introducing hydrogen and a silicon gas and applying a first high-frequency electric power of an HF band and a second high-frequency electric power of a VHF band superimposed on each other; and hydrogen plasma being made to act on a reaction product formed on a surface of the gate insulating film to etch the reaction product while forming the microcrystalline semiconductor film. ### Claim 13 (depends on 12) The method of manufacturing a display device according to claim 12, wherein the microcrystalline semiconductor film has an oxygen concentration of 1×1017 atoms/cm3 or less. ### Claim 14 (depends on 12) The method of manufacturing a display device according to claim 12, wherein trimethylboron is introduced in the microcrystalline semiconductor film so that an i-type or p-type microcrystalline semiconductor film is formed. ### Claim 15 (depends on 12) The method of manufacturing a display device according to claim 12, wherein the amorphous semiconductor film is formed over the microcrystalline semiconductor film without exposure of a surface of the microcrystalline semiconductor film to the air. ### Claim 16 A method of manufacturing a display device, comprising: forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming a microcrystalline semiconductor film over the gate insulating film by a plasma CVD method; and forming an amorphous semiconductor film over the microcrystalline semiconductor film, wherein the step of forming the microcrystalline semiconductor film comprises: a pressure of a reaction chamber being set at or below 10−5 Pa; a temperature of the substrate being set in a range of 100° C. to 200° C.; plasma being generated by introducing hydrogen and a rare gas and applying a first high-frequency electric power of an HF band and a second high-frequency electric power of a VHF band superimposed on each other; and hydrogen plasma and rare gas plasma being made to act on a reaction product formed on a surface of the gate insulating film to etch the reaction product while forming the microcrystalline semiconductor film by introducing a silicon gas. ### Claim 17 (depends on 16) The method of manufacturing a display device according to claim 16, wherein the microcrystalline semiconductor film has an oxygen concentration of 1×1017 atoms/cm3 or less. ### Claim 18 (depends on 16) The method of manufacturing a display device according to claim 16, wherein trimethylboron is introduced in the microcrystalline semiconductor film so that an i-type or p-type microcrystalline semiconductor film is formed. ### Claim 19 (depends on 16) The method of manufacturing a display device according to claim 16, wherein the amorphous semiconductor film is formed over the microcrystalline semiconductor film without exposure of a surface of the microcrystalline semiconductor film to the air. ### Claim 20 (depends on 16) The method of manufacturing a display device according to claim 16, wherein the introduction of the rare gas is stopped before the introduction of the silicon gas. ### Claim 21 (depends on 16) The method of manufacturing a display device according to claim 16, wherein the introduction of the rare gas is stopped after the introduction of the silicon gas, wherein a predetermined period is interposed between the introduction of the silicon gas and the stop of the rare gas. ### Claim 22 (depends on 16) The method of manufacturing a display device according to claim 16, wherein argon is used as the rare gas.