Semiconductor device and manufacturing method thereof

Abstract

To provide a semiconductor device in which a defect or fault is not generated and a manufacturing method thereof even if a ZnO semiconductor film is used and a ZnO film to which an n-type or p-type impurity is added is used for a source electrode and a drain electrode. The semiconductor device includes a gate insulating film formed by using a silicon oxide film or a silicon oxynitride film over a gate electrode, an Al film or an Al alloy film over the gate insulating film, a ZnO film to which an n-type Or p-type impurity is added over the Al film or the Al alloy film, and a ZnO semiconductor film over the ZnO film to which an n-type or p-type impurity is added and the gate insulating film.

1 - 4 . (canceled) 
   
   
       5 . A method of manufacturing a semiconductor device comprising the steps of:
 forming a gate electrode over a substrate;   forming a first insulating film over the gate electrode;   forming an oxide semiconductor film over the gate electrode with the first insulating film interposed therebetween;   patterning the oxide semiconductor film by dry etching to form an island-shape oxide semiconductor film, the island-shape oxide semiconductor film including a channel formation region; and   forming a silicon containing insulating film by sputtering over the island-shape oxide semiconductor film, the silicon containing insulating film being in contact with the island-shape oxide semiconductor film.   
   
   
       6 . The method according to  claim 5  wherein the oxide semiconductor film comprises zinc oxide. 
   
   
       7 . The method according to  claim 5  wherein the first insulating film is formed by sputtering. 
   
   
       8 . The method according to  claim 5  wherein the oxide semiconductor film is formed by sputtering. 
   
   
       9 . The method according to  claim 5  wherein the silicon containing insulating film comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide. 
   
   
       10 . A method of manufacturing a semiconductor device comprising the steps of:
 forming a gate electrode over a substrate;   forming a first insulating film over the gate electrode;   forming a pair of first conductive layers each comprising a metal film;   forming a pair of second conductive layers on the pair of first conductive layers, each of the pair of second conductive layers comprising zinc oxide;   forming an island-shape oxide semiconductor film over the pair of second conductive layers and the gate electrode wherein the first insulating film is interposed between the gate electrode and the island-shape oxide semiconductor film; and   forming a silicon containing insulating film by sputtering over the island-shape oxide semiconductor film, the silicon containing insulating film being in contact with the island-shape oxide semiconductor film.   
   
   
       11 . The method according to  claim 10  wherein the island-shape oxide semiconductor film comprises zinc oxide. 
   
   
       12 . The method according to  claim 10  wherein the first insulating film is formed by sputtering. 
   
   
       13 . The method according to  claim 10  wherein the silicon containing insulating film comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide. 
   
   
       14 . The method according to  claim 10  wherein each of the pair of first conductive layers comprises an aluminum film. 
   
   
       15 . The method according to  claim 10  wherein each of the pair of first conductive layers comprises an aluminum film and a titanium film in contact with the aluminum film and one of the pair of second conductive layers. 
   
   
       16 . The method according to  claim 10  wherein the pair of second conductive layers are formed by dry etching. 
   
   
       17 . A method of manufacturing a semiconductor device comprising the steps of:
 forming a gate electrode over a substrate;   forming a first insulating film over the gate electrode;   forming a pair of first conductive layers each comprising a metal film;   forming a pair of second conductive layers on the pair of first conductive layers, each of the pair of second conductive layers comprising zinc oxide;   forming an oxide semiconductor film over the pair of second conductive layers and the gate electrode wherein the first insulating film is interposed between the gate electrode and the oxide semiconductor film;   patterning the oxide semiconductor film by dry etching to form an island-shape oxide semiconductor film; and   forming a silicon containing insulating film by sputtering over the island-shape oxide semiconductor film, the silicon containing insulating film being in contact with the island-shape oxide semiconductor film.   
   
   
       18 . The method according to  claim 17  wherein the oxide semiconductor film comprises zinc oxide. 
   
   
       19 . The method according to  claim 17  wherein the first insulating film is formed by sputtering. 
   
   
       20 . The method according to  claim 17  wherein the oxide semiconductor film is formed by sputtering. 
   
   
       21 . The method according to  claim 17  wherein the silicon containing insulating film comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide. 
   
   
       22 . The method according to  claim 17  wherein each of the pair of first conductive layers comprises an aluminum film. 
   
   
       23 . The method according to  claim 17  wherein each of the pair of first conductive layers comprises an aluminum film and a titanium film in contact with the aluminum film and one of the pair of second conductive layers. 
   
   
       24 . The method according to  claim 17  wherein the pair of second conductive layers are formed by dry etching. 
   
   
       25 . A method of manufacturing a semiconductor device comprising the steps of:
 forming a gate electrode over a substrate;   forming a first insulating film over the gate electrode;   forming an oxide semiconductor film over the gate electrode with the first insulating film interposed therebetween;   patterning the oxide semiconductor film by dry etching to form an island-shape oxide semiconductor film, the island-shape oxide semiconductor film including a channel formation region.   
   
   
       26 . The method according to  claim 25  wherein the oxide semiconductor film is patterned by dry etching using a hydrocarbon gas. 
   
   
       27 . The method according to  claim 26  wherein the hydrocarbon gas is CH 4 . 
   
   
       28 . The method according to  claim 25  wherein the oxide semiconductor film comprises zinc oxide. 
   
   
       29 . A method of manufacturing a semiconductor device comprising the steps of:
 forming an oxide semiconductor film over a substrate; and   patterning the oxide semiconductor film by dry etching to form an island-shape oxide semiconductor film.   
   
   
       30 . The method according to  claim 29  wherein the oxide semiconductor film is patterned by dry etching using a hydrocarbon gas. 
   
   
       31 . The method according to  claim 30  wherein the hydrocarbon gas is CH 4 . 
   
   
       32 . The method according to  claim 29  wherein the oxide semiconductor film comprises zinc oxide. 
   
   
       33 . The method according to  claim 29  wherein the oxide semiconductor film is formed by sputtering.