Method of forming a trench for use in manufacturing a semiconductor device

Abstract

A method for use in manufacturing a semiconductor device includes forming a photoresist pattern on a substrate, performing first etching process in which an initial trench is formed using the photoresist pattern as a mask, and performing second distinct etching process to enlarge the initial trench. Thus, the initial trench can be formed using the photoresist pattern having a stable structure. Thereafter, the trench is enlarged using an etching solution having a composition based on the material in which the initial trench is formed, e.g., silicon substrate or an insulation film. Therefore, a metal wiring, an isolation film or a contact can be formed in the enlarged trench to desired dimensions.

1 . A method of forming an isolation film for use in manufacturing of a semiconductor device, said method comprising: 
 forming a photoresist pattern on a substrate;    performing a first etching process comprising etching the substrate using the photoresist pattern as a mask to form an initial trench in the substrate;    subsequently performing a second etching process that is distinct from said first etching process, said second etching process comprising etching the substrate in which the initial trench is already formed to thereby enlarge the initial trench; and    subsequently forming an oxide film that fills the enlarged trench.    
   
   
       2 . The method of  claim 1 , wherein said forming of the oxide film comprises forming an initial oxide film on the substrate in and around the enlarged trench, and subsequently removing a portion of the initial oxide film from a top surface of the substrate while leave another portion of the initial oxide film in the enlarged trench.  
   
   
       3 . The method of  claim 1 , wherein said second etching process comprises wetting the substrate with an etching solution that etches silicon.  
   
   
       4 . The method of  claim 2 , wherein the etching solution includes hydrogen fluoride, nitric acid (HNO 3 ) and deionized water.  
   
   
       5 . A method for manufacturing a semiconductor device comprising: 
 forming a first insulation film on a substrate;    forming a first conductive pattern in the insulation film;    forming at least one etch stop layer and at least one second insulation film in the foregoing sequence on the first insulation film;    forming a first photoresist pattern on the second insulation film;    etching the etch stop layer and the second insulation film using the first photoresist pattern as a mask to form a via hole that exposes the first conductive pattern by removing the first photoresist pattern;    subsequently forming a second photoresist pattern on the second insulation film, the second photoresist pattern having an opening aligned with the via hole;    etching the stop layer and the second insulation film using the second photoresist pattern as a mask to thereby form an initial trench aligned with the via hole;    subsequently etching the second insulation film to enlarge the initial trench; and    depositing a conductive material in the via hole and in the enlarged trench to thereby form a second conductive pattern and a third conductive pattern in the via hole and in the enlarged trench, respectively.