Semiconductor device with vertical transistors having a surrounding gate and a work-function metal around an upper sidewall

Abstract

A method of manufacturing a semiconductor device includes a first step of forming a fin-shaped semiconductor layer, a first insulating film around the fin-shaped semiconductor layer, and a pillar-shaped semiconductor layer on the fin-shaped semiconductor layer. A second step forms a gate insulating film around the pillar-shaped semiconductor layer, a gate electrode around the gate insulating film, and a gate line. A third step forms a first first-conductivity-type diffusion layer in an upper portion of the pillar-shaped semiconductor layer and a second first-conductivity-type diffusion layer in a lower portion of the pillar-shaped semiconductor layer and an upper portion of the fin-shaped semiconductor layer. A fourth step includes depositing, planarizing, and etching-back a first interlayer insulating film to expose an upper portion of the pillar-shaped semiconductor layer, depositing a first metal, and etching the metal to form a first sidewall around the upper portion of the pillar-shaped semiconductor layer.

1 . A semiconductor device, comprising:
 a pillar-shaped semiconductor layer;   a gate insulating film formed around said pillar-shaped semiconductor layer;   a gate electrode formed around said gate insulating film;   a gate line connected to said gate electrode; and   a first sidewall composed of a first metal and formed around a sidewall of an upper portion of said pillar-shaped semiconductor layer.   
     
     
         2 . The semiconductor device according to  claim 1 , further comprising a first metal line formed on an upper portion of said pillar-shaped semiconductor layer and on said first sidewall. 
     
     
         3 . The semiconductor device according to  claim 1 , wherein said semiconductor layers are silicon layers. 
     
     
         4 . The semiconductor device according to  claim 3 , wherein said metal of said first sidewall has a work function between 4.0 eV and 4.2 eV. 
     
     
         5 . The semiconductor device according to  claim 3 , wherein said metal of said first sidewall has a work function between 5.0 eV and 5.2 eV. 
     
     
         6 . The semiconductor device according to  claim 1 , wherein said first sidewall has a laminated structure of said gate insulating film and said first metal. 
     
     
         7 . A semiconductor device, comprising a first metal forming a sidewall around an upper portion of a semiconductor pillar.