Post-chemical mechanical polishing (CMP) cleaning method

Abstract

Disclosed herein is a post-CMP cleaning method for effectively removing residues, including nitride particles and oxide particles produced in the chemical mechanical polishing (CMP) of a trench-buried oxide film and a pad oxide film as an etch barrier, which is carried out during a process of forming an isolation region in a semiconductor substrate using shallow trench isolation (STI). The post-CMP cleaning method comprises cleaning the substrate with a cleaning solution having a pH below 3 or above 9, so that the substrate surface, including the oxide film and the nitride film, has the same electric polarity as that of the nitride and oxide particles such that a repulsive force acts between the substrate surface and the nitride particles and between the substrate surface and the oxide particles, thereby effectively removing the nitride particles and the oxide particles.

What is claimed is:  
     
         1 . A post-CMP cleaning method for removing residues, including nitride particles and oxide particles produced in the chemical mechanical polishing (CMP) of a trench-buried oxide film and a pad oxide film as an etch barrier, which is carried out during a process of forming an isolation region in a semiconductor substrate using shallow trench isolation (STI), 
 the post-CMP cleaning method comprising cleaning the substrate with a cleaning solution having a pH below 3 or above 9, so that the substrate surface, including the oxide film and the nitride film, has the same electric polarity as that of the nitride and oxide particles such that a repulsive force acts between the substrate surface and the nitride particles and between the substrate surface and the oxide particles, thereby effectively removing the nitride particles and the oxide particles.    
     
     
         2 . The method of  claim 1 , wherein the cleaning solution is maintained at a pH below 3 by the addition of a HF or HCl solution.  
     
     
         3 . The method of  claim 1 , wherein the cleaning solution is maintained at a pH above 9 by the addition of a KOH or NaOH solution.