Semiconductor device having an etch stopper formed of a SiN layer by low temperature ALD and method of fabricating the same

Abstract

Provided are a semiconductor device having an etch stopper formed of a nitride film by low temperature atomic layer deposition which can prevent damage to a semiconductor substrate and a method for fabricating the semiconductor device. Damage to the semiconductor substrate under the etch stopper composed of a second nitride film can be prevented by forming a first nitride film using high temperature LPCVD on the semiconductor substrate, forming the etch stopper including the second nitride film by low temperature ALD on the first nitride film, and removing the second nitride film by dry etching, thus taking advantage of the different etch selectivities of the first nitride film and the second nitride film.

1 . A method for fabricating a semiconductor device comprising: 
 forming a gate pattern on a semiconductor substrate in which the gate pattern includes sidewalls;    forming an etch stopper which covers the gate pattern and the semiconductor substrate to a predetermined thickness using low temperature atomic layer deposition;    depositing an interlayer insulating film on the semiconductor substrate where the etch stopper is formed;    forming a self-aligned contact hole by dry etching the interlayer insulating film using the gate pattern as a mask; and    removing the etch stopper which is exposed to the self-aligned contact hole by wet etching.    
   
   
       2 . The method of  claim 1 , wherein said removing the etch stopper which is exposed to the self-aligned contact hole by wet etching is followed by the steps of: 
 forming an interconnection on the semiconductor device; and    packaging the device in a semiconductor device package.    
   
   
       3 . The method of  claim 1 , wherein the etch stopper comprises a nitride film.  
   
   
       4 . The method of  claim 1 , wherein the gate pattern comprises a nitride film formed using low pressure chemical vapor deposition.  
   
   
       5 . The method of  claim 4 , wherein the etch stopper comprises a second nitride film.  
   
   
       6 . The method of  claim 1 , wherein, as a reaction gas for forming the etch stopper, one of SiH 4 , SiCl 2 H 2 , and SiCl 4  is used as a silicon source, and one of N 2 , NH 3 , and N 2 O is used as a nitrogen source.  
   
   
       7 . The method of  claim 1 , wherein the interlayer insulating film is a single layer film formed of an oxide film including SiO 2 , BPSG, HDP oxide, Fox.  
   
   
       8 . The method of  claim 1 , wherein the interlayer insulating film is a multi-layer film including films comprising an oxide film including SiO 2 , BPSG, HDP oxide, Fox.  
   
   
       9 . The method of  claim 1 , wherein the dry etching for forming the self-aligned contact hole continues until the etch stopper is exposed.  
   
   
       10 . The method of  claim 1 , wherein a hydrofluoric acid solution as an etching solution is used in the wet etching for removing the etch stopper.  
   
   
       11 . The method of  claim 1 , wherein the wet etching for removing the etch stopper employs a SC1 cleaning method.