Method for manufacturing a semiconductor device

Abstract

The present invention makes it possible to increase the selectivity of a gate insulation film in an active element formed in a wiring layer. A semiconductor device according to the present invention has a bottom gate type transistor using an antireflection film formed over an Al wire in a wiring layer as a gate wire.

What is claimed is: 
     
         1 . A method for manufacturing a semiconductor device including the steps of:
 forming an underlying logic element over a substrate;   forming an aluminum wire in a wiring layer over the underlying logic element;   forming an antireflection film over the aluminum wire;   forming a gate insulation film and an oxide semiconductor layer in sequence from the lower layer over the antireflection film, and   forming a source contact and a drain contact coupled to the oxide semiconductor layer.   
     
     
         2 . A method for manufacturing a semiconductor device according to  claim 1 ,
 wherein the step of forming an aluminum wire includes a step of forming a first aluminum wire and a second aluminum wire in an identical process;   the step of forming an antireflection film includes a step of forming a first antireflection film over the first aluminum wire and a second antireflection film over the second aluminum wire in an identical process;   the step of forming a gate insulation film and an oxide semiconductor layer includes steps of forming a first gate insulation film, a first oxide semiconductor layer, and a first hard mask in sequence from the lower layer over the first antireflection film, forming an insulation film for a second gate insulation film, an oxide semiconductor layer for a second oxide semiconductor layer, and a second hard mask in sequence from the lower layer over the first hard mask and the second antireflection film, and forming the second gate insulation film and the second oxide semiconductor layer over the second antireflection film by etching;   the step of forming a source contact and a drain contact includes a step of forming a first source contact and a first drain contact coupled to the first oxide semiconductor layer and a second source contact and a second drain contact coupled to the second oxide semiconductor layer in an identical process, and   the conductivity type of the first oxide semiconductor layer is different from the conductivity type of the second oxide semiconductor layer.   
     
     
         3 . A method for manufacturing a semiconductor device according to  claim 2 ,
 wherein the first aluminum wire is coupled to the second aluminum wire, and   the first drain contact is coupled to the second drain contact through a wire.