Method for manufacturing oxide thin film transistor

Abstract

A method for manufacturing an oxide thin film transistor with leakage currents less than 10 −14 angstrom includes the steps of forming an oxide semiconductor active layer by a deposition process. In the deposition process, an electric power is in a range from 1.5 kilowatts to 10 kilowatts. The oxide thin film transistor manufactured by the above methods has advantages of low leakage currents, high electron mobility, and excellent temperature stability. The present invention also provides a method for manufacturing a display device. The display quality of the display device can be improved.

What is claimed is: 
     
         1 . A method for manufacturing an oxide thin film transistor with leakage currents less than 10 −14  angstrom, comprising: forming an oxide semiconductor active layer by a deposition process, wherein a gas used in the deposition process comprises oxygen with a flow ratio to the total gas in a range from 4% to 20%. 
     
     
         2 . The method for manufacturing an oxide thin film transistor as claimed in  claim 1 , wherein the deposition process is a sputtering deposition process. 
     
     
         3 . The method for manufacturing an oxide thin film transistor as claimed in  claim 1 , wherein material of the oxide semiconductor active layer is selected from the group consisting of zinc oxide, zinc tin oxide, chromium zinc oxide, gallium zinc oxide, titanium zinc oxide, indium gallium zinc oxide, copper aluminum oxide, strontium copper oxide, lanthanum copper oxide and any combination thereof. 
     
     
         4 . The method for manufacturing an oxide thin film transistor as claimed in  claim 1 , wherein a thickness of the oxide semiconductor active layer is in a range from 300 angstroms to 2000 angstroms. 
     
     
         5 . The method for manufacturing an oxide thin film transistor as claimed in  claim 1 , wherein the gas used in the deposition process further comprises argon. 
     
     
         6 . The method for manufacturing an oxide thin film transistor as claimed in  claim 1 , wherein an electric power used in the deposition process is in range from 1.5 kilowatts to 10 kilowatts. 
     
     
         7 . A method for manufacturing an oxide thin film transistor with leakage currents less than 10 −14  angstrom, comprising: forming an oxide semiconductor active layer with a thickness in a range from 300 angstroms to 2000 angstroms by a deposition process. 
     
     
         8 . The method for manufacturing an oxide thin film transistor as claimed in  claim 6 , wherein the deposition process is a sputtering deposition process. 
     
     
         9 . The method for manufacturing an oxide thin film transistor as claimed in  claim 6 , wherein material of the oxide semiconductor active layer is selected from the group consisting of zinc oxide, zinc tin oxide, chromium zinc oxide, gallium zinc oxide, titanium zinc oxide, indium gallium zinc oxide, copper aluminum oxide, strontium copper oxide, lanthanum copper oxide and any combination thereof. 
     
     
         10 . The method for manufacturing an oxide thin film transistor as claimed in  claim 6 , wherein an electric power used in the deposition process is in range from 1.5 kilowatts to 10 kilowatts. 
     
     
         11 . A method for manufacturing an oxide thin film transistor with leakage currents less than 10 −14  angstrom, comprising: forming an oxide semiconductor active layer by a deposition process, wherein an electric power used in the deposition process is in range from 1.5 kilowatts to 10 kilowatts. 
     
     
         12 . The method for manufacturing an oxide thin film transistor as claimed in  claim 11 , wherein the deposition process is a sputtering deposition process. 
     
     
         13 . The method for manufacturing an oxide thin film transistor as claimed in  claim 11 , wherein material of the oxide semiconductor active layer is selected from the group consisting of zinc oxide, zinc tin oxide, chromium zinc oxide, gallium zinc oxide, titanium zinc oxide, indium gallium zinc oxide, copper aluminum oxide, strontium copper oxide, lanthanum copper oxide and any combination thereof.