Method of manufacturing a semiconductor device having fin-shaped field effect transistor

Abstract

Disclosed is a semiconductor device including: an active region defined by an element isolation region; a gate trench going across the active region to define source/drain regions on both sides thereof, respectively, and to define, between the source/drain regions, the channel region having a first, second, and third protruding portions which are arranged in a gate width direction; and a gate electrode formed in the gate trench so as to cover the channel region through a gate insulating film.

What is claimed is: 
     
         1 . A method for manufacturing a semiconductor device comprising:
 patterning element isolation regions on a substrate so as to define an active region therein;   forming a gate trench by anisotropic etching, said gate trench crossing the active region to define source and drain regions on both sides of the gate trench, and a channel region between said source and drain regions, the channel region having multiple protruding portions arranged in a gate width direction, and at least one of said multiple protruding portions defining a fin-shaped channel region;   forming a gate insulating film so as to cover the bottom and side surfaces of the gate trench; and   forming a gate electrode in the gate trench so as to cover the channel region with an intervention of a gate insulating film therebetween.   
     
     
         2 . The method according to  claim 1 , wherein the channel region has first, second and third protruding portions. 
     
     
         3 . The method according to  claim 2 , wherein the channel regions includes an upward protruding portion and a downward protruding portion. 
     
     
         4 . The method according to  claim 1 , wherein the substrate is a silicon substrate. 
     
     
         5 . The method according to  claim 1 , wherein the patterning includes forming a pad oxide film on the substrate. 
     
     
         6 . The method according to  claim 5 , wherein the pad oxide film has a width of 3 nm to 10 nm. 
     
     
         7 . The method according to  claim 5 , wherein a field nitride film is formed on the pad oxide film. 
     
     
         8 . The method according to  claim 7 , wherein the field nitride film has a thickness of 30 nm to 100 nm. 
     
     
         9 . The method according to  claim 5 , wherein an upper surface of the isolation film is set at a substantially same level and an upper surface of the pad oxide film. 
     
     
         10 . The method according to  claim 1 , wherein the element isolation regions are formed by chemical vapor deposition, high density plasma or spun on glass. 
     
     
         11 . The method according to  claim 1 , wherein the element isolation regions the chemical mechanical polishing. 
     
     
         12 . The method according to  claim 1 , wherein upper surfaces of the element isolation regions are formed below the upper surface of the active region. 
     
     
         13 . The method according to  claim 1 , wherein the anisotropic etching is performed using plasma containing freon gas. 
     
     
         14 . The method according to  claim 13 , wherein the anisotropic etching is performed with an etching gas containing CHF 3 , C 4 F 8 , O 2  and Ar. 
     
     
         15 . The method according to  claim 1 , wherein the anisotropic etching is performed in an etching chamber at a pressure of 10 Pa to 20 Pa, and an RF bias power is set to a range of 700 W to 1200 W. 
     
     
         16 . The method according to  claim 1 , wherein side etching is applied to the active region. 
     
     
         17 . The method according to  claim 16 , wherein the side etching exposes apart of the active regions portion at aside wall bottom portion of a removed part. 
     
     
         18 . The method according to  claim 1 , wherein there are first and second anisotropic etchings. 
     
     
         19 . The method according to  claim 18 , wherein the second anisotropic etching forms the protruding portions. 
     
     
         20 . The method according to  claim 1 , wherein the active region is etched deeper than the element isolation regions.