Semiconductor device having a nitride barrier for preventing formation of structural defects

Abstract

Providing a method of producing a semiconductor device and a structure of the semiconductor device employing a trench isolation structure for isolating semiconductor elements wherein volumetric expansion of a trench-filling material due to oxidation process after forming the trench isolation structure is controlled thereby making it possible to prevent deterioration of the electrical characteristics of the semiconductor device. A nitriding treatment is applied to the trench surface of the silicon substrate after forming the trench by etching, thereby to form a thin nitride layer having a better effect of preventing oxidation in the interface of silicon.

What is claimed is:  
     
         1 . A semiconductor, comprising: 
 (a) a substrate having a surface, said surface being formed with a groove to define a first region on one side of said groove and a second region on the opposite side of said groove;    (b) first and second transistors provided in said first and second region, respectively, 
 each of said first and second transistors having a gate oxidation film provide on said surface, a gate electrode provided on said gate oxidation film, and impurity-doped layers positioned on either sides of said gate electrode and between said substrate and gate oxidation film;  
   (c) an insulator filled in said groove; and    (d) a nitride layer positioned on a surface of said groove to separate said insulator from a surface of said groove.    
     
     
         2 . The semiconductor device according to  claim 1 , wherein said nitride layer is formed on the full surface of said groove.  
     
     
         3 . The semiconductor device according to  claim 1 , further comprising an oxidation film formed on the surface of the groove, wherein said nitride layer is provided by nitriding said surface of the groove through an oxidation film.  
     
     
         4 . The semiconductor device according to  claim 1 , wherein said insulator is an oxidation film formed by CVD method.  
     
     
         5 . The semiconductor device according to  claim 1 , wherein said nitride layer is formed to prevent said surface of the groove from being oxidized.  
     
     
         6 . A method of producing the semiconductor device having a plurality of transistors comprising a semiconductor substrate of first conductivity type having a principal plane, a gate electrode formed on the principal plane via a gate oxidation film and impurity-doped layers of the second conductivity type formed on the principal plane on both sides of the gate electrode, wherein a step of isolating the plurality of transistors from each other comprising the steps of: 
 (a) forming a groove by etching the semiconductor substrate;    (b) nitriding the surface of the groove to form a nitride layer; and    (c) filling the groove with an insulator.    
     
     
         7 . The method according to  claim 6 , further comprising the step of: 
 forming an oxidation film on the surface of the groove, wherein the step of nitriding the surface of the groove comprises a step of nitriding treatment carried out by nitriding the surface of the groove through the oxidation film thereby to form a nitride layer on the surface of the groove.    
     
     
         8 . The method according to  claim 6 , wherein the step of nitriding the surface of the groove comprises a step of nitriding treatment of the surface of the groove carried out by using a nitrogen monoxide gas.  
     
     
         9 . The method according to  claim 8 , wherein the nitriding treatment is carried out at a temperature of not less than 800° C.  
     
     
         10 . The method according to  claim 6 , wherein the step of nitriding the surface of the groove comprises a step of nitriding treatment of the surface of the groove carried out by using an ammonia gas.  
     
     
         11 . The method according to  claim 10 , wherein the nitriding treatment is carried out at a temperature of not less than 700° C.  
     
     
         12 . The method according to  claim 6 , wherein the step of filling the groove with an insulator is comprises a step of filling the groove with an oxidation film formed by CVD method.