Semiconductor device and manufacturing method thereof

Abstract

It is an object of the present invention to provide a semiconductor device where, even in a case of stacking a plurality of semiconductor elements provided over a substrate, the stacked semiconductor elements can be electrically connected through the substrate, and a manufacturing method thereof. According to one feature of the present invention, a method for manufacturing a semiconductor device includes the steps of selectively forming a depression in an upper surface of a substrate or forming an opening which penetrates the upper surface through a back surface; forming an element group having a transistor so as to cover the upper surface of the substrate and the depression, or the opening; and exposing the element group formed in the depression or the opening by thinning the substrate from the back surface. A means for thinning the substrate can be performed by partially removing the substrate by performing grinding treatment, polishing treatment, etching by chemical treatment, or the like from the back surface of the substrate.

1 . (canceled) 
     
     
         2 . A method for manufacturing a semiconductor device comprising:
 forming a depression in a semiconductor substrate;   forming a first insulating film over the semiconductor substrate and in the depression of the semiconductor substrate;   forming a conductive film over the first insulating film and in the depression; and   removing a portion of the semiconductor substrate such that a portion of the conductive film in the depression continuously extends through the semiconductor substrate and the first insulating film.   
     
     
         3 . The method according to  claim 2 , wherein the semiconductor substrate includes a channel region of an FET. 
     
     
         4 . The method according to  claim 2 , further comprising a second insulating film over the first insulating film, wherein the conductive film is formed after forming the second insulating film. 
     
     
         5 . The method according to  claim 2 , wherein the portion of the semiconductor substrate is removed by thinning. 
     
     
         6 . The method according to  claim 2 , wherein the portion of the semiconductor substrate is removed by polishing. 
     
     
         7 . A method for manufacturing a semiconductor device comprising:
 forming a depression in a semiconductor substrate at a first side of the semiconductor substrate;   forming a first insulating film over the semiconductor substrate and in the depression of the semiconductor substrate;   forming a conductive film over the first insulating film, wherein a portion of the conductive film is formed in the depression; and   removing a portion of the semiconductor substrate such that the portion of the conductive film is exposed at a second side of the semiconductor substrate opposite to the first side.   
     
     
         8 . The method according to  claim 7 , wherein the semiconductor substrate includes a channel region of an FET. 
     
     
         9 . The method according to  claim 7 , further comprising a second insulating film over the first insulating film, wherein the conductive film is formed after forming the second insulating film. 
     
     
         10 . The method according to  claim 7 , wherein the portion of the semiconductor substrate is removed by thinning. 
     
     
         11 . The method according to  claim 7 , wherein the portion of the semiconductor substrate is removed by polishing. 
     
     
         12 . A method for manufacturing a semiconductor device comprising:
 forming an opening in a semiconductor substrate to a depth not greater than a thickness of the semiconductor substrate;   forming a first insulating film over the semiconductor substrate and in the opening of the semiconductor substrate;   forming a conductive film over the first insulating film and in the opening; and   removing a portion of the semiconductor substrate such that a portion of the conductive film in the opening continuously extends through the semiconductor substrate and the first insulating film.   
     
     
         13 . The method according to  claim 12 , wherein the semiconductor substrate includes a channel region of an FET. 
     
     
         14 . The method according to  claim 12 , further comprising a second insulating film over the first insulating film, wherein the conductive film is formed after forming the second insulating film. 
     
     
         15 . The method according to  claim 12 , wherein the portion of the semiconductor substrate is removed by thinning. 
     
     
         16 . The method according to  claim 12 , wherein the portion of the semiconductor substrate is removed by polishing. 
     
     
         17 . A method for manufacturing a semiconductor device comprising:
 forming an opening in a semiconductor substrate to a depth not greater than a thickness of the semiconductor substrate at a first side of the semiconductor substrate;   forming a first insulating film over the semiconductor substrate and in the opening of the semiconductor substrate;   forming a conductive film over the first insulating film, wherein a portion of the conductive film is formed in the opening; and   removing a portion of the semiconductor substrate such that the portion of the conductive film is exposed at a second side of the semiconductor substrate opposite to the first side.   
     
     
         18 . The method according to  claim 17 , wherein the semiconductor substrate includes a channel region of an FET. 
     
     
         19 . The method according to  claim 17 , further comprising a second insulating film over the first insulating film, wherein the conductive film is formed after forming the second insulating film. 
     
     
         20 . The method according to  claim 17 , wherein the portion of the semiconductor substrate is removed by thinning. 
     
     
         21 . The method according to  claim 17 , wherein the portion of the semiconductor substrate is removed by polishing.