Topcoat process to prevent image collapse

Abstract

The invention relates generally to photolithographic techniques, and particularly, but not by way of limitation, to a method for preventing the collapse of the image pattern during the stage of drying the image. The invention also relates to structures fabricated using the inventive method.

What is claimed is:  
     
         1 . A substantially non-distorting method of stabilizing a developed resist image comprising: 
 providing a developed resist image;    overcasting said image with a stabilizing film; and    removing said stabilizing film using a low surface tension fluid.    
     
     
         2 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 1 , wherein providing a developed resist image comprises: 
 providing a wafer mounted on a spin coater;    applying photoresist to said wafer;    imaging said photoresist forming a resist image;    developing said resist image;    immersing said resist image in a rinse fluid;    and maintaining said resist image submerged in rinse fluid.    
     
     
         3 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 2 , wherein developing comprises aqueous tetraalkylammonium hydroxide.  
     
     
         4 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 2 , wherein said rinse fluid comprises distilled water.  
     
     
         5 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 2 , wherein said rinse fluid comprises xylene.  
     
     
         6 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 1 , wherein overcasting comprises: 
 providing film-forming polymers in said rinse fluid;    spin coating forming said stabilizing film from said polymers; and    removing said stabilizing film and said rinse fluid using a low surface tension fluid.    
     
     
         7 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 6 , wherein the thickness of said stabilizing film is from about 0.1 micron to about 5 microns.  
     
     
         8 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 6 , wherein the thickness of said stabilizing film is at least twice the thickness of the resist image.  
     
     
         9 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 6 , wherein said film-forming polymers are miscible with both said rinse fluid and with said low surface tension fluid.  
     
     
         10 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 9 , wherein said film-forming polymers are derived from polyalkenoxides and copolymers thereof.  
     
     
         11 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 5 , wherein said polymers comprise fluoroaliphatic polyether surfactants.  
     
     
         12 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 6 , wherein said low surface tension fluid comprises CO 2 .  
     
     
         13 . A substantially non-distorting method of stabilizing a developed resist image, according to clam  12 , wherein said CO 2  is supercritical.  
     
     
         14 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 12 , wherein said CO 2  is liquid.  
     
     
         15 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 6 , wherein said low surface tension fluid comprises CO 2  and a about 5% (by volume) of a cosolvent wherein said cosolvent is miscible in fluid CO 2 .  
     
     
         16 . A substantially non-distorting method of stabilizing a developed resist image, according to  claim 15 , wherein said cosolvent is chosen from the group consisting of methanol, ethanol, isopropanol, and xylene.  
     
     
         17 . The substantially non-distorted resist image fabricated by the method of  claim 1 .  
     
     
         18 . The semiconductor device fabricated using the resist image according to  claim 6 .  
     
     
         20 . The structure fabricated using the resist image according to  claim 6.