Semiconductor device manufacaturing method and silicon oxide film forming method

Abstract

A semiconductor device manufacturing method has forming element isolation trenches in a semiconductor substrate, forming a silicon compound film in insides of the element isolation trenches in order to embed the element isolation trenches, conducting a first oxidation processing at a first temperature to reform a surface of the silicon compound film to a volatile matter emission preventing layer which permits passage of an oxidizing agent and impurities and which does not permit passage of a volatile matter containing silicon atoms, and conducting a second oxidation processing at a second temperature which is higher than the first temperature to form a coated silicon oxide film inside the element isolation trenches.

1 .- 20 . (canceled) 
     
     
         21 . A semiconductor device manufacturing method comprising:
 forming a gate isolation film on a semiconductor substrate;   forming a gate electrode on the gate isolation film;   forming an element isolation trench in the gate electrode, the gate isolation film and the semiconductor substrate;   forming an impurity diffusion preventing film in the element isolation trench;   forming a silicon compound film in insides of the element isolation trench in order to embed the element isolation trench that the impurity diffusion preventing film is formed;   conducting a first oxidation process to reform a surface of the silicon compound film at a first temperature; and   conducting a second oxidation process to form a coated silicon oxide film from the silicon compound film at a second temperature, the second temperature being higher than the first temperature,   wherein the first oxidation process is ozone oxidation.   
     
     
         22 . The semiconductor device manufacturing method according to  claim 21 , wherein the impurity diffusion preventing film is formed by using a CVD method. 
     
     
         23 . The semiconductor device manufacturing method according to  claim 21 , wherein the impurity diffusion preventing film is a silicon oxide film. 
     
     
         24 . The semiconductor device manufacturing method according to  claim 21 , further comprising conducting a warm water processing process between the first oxidation process and the second oxidation process. 
     
     
         25 . The semiconductor device manufacturing method according to  claim 21 , further comprising conducting a third oxidation process after the coated silicon oxide film is formed. 
     
     
         26 . The semiconductor device manufacturing method according to  claim 25 , wherein the third oxidation process is ozone oxidation. 
     
     
         27 . The semiconductor device manufacturing method according to  claim 21 , wherein the second oxidation process is an oxidation conducted in a steam (H 2 ) atmosphere or an oxide atmosphere. 
     
     
         28 . The semiconductor device manufacturing method according to  claim 21 , wherein the first oxidation process is conducted at a temperature of 300° C. or less. 
     
     
         29 . The semiconductor device manufacturing method according to  claim 21 , wherein the silicon compound film is either polysilazane (polyperhydrosilazane) or hydrogen silses quioxane (HSQ).