Metal safe stabilized stripper for removing cured polymeric layers and negative tone acrylic photoresists

Abstract

A stabilized stripping composition is provided for removing fully cured polymeric organic substances from an inorganic substrate, including polyimide and liquid crystal polymer (LCP). The stripping composition comprises about 3 to about 15 percent of benzyltrimethylammonium hydroxide (BTMAH), about 50 to about 87.5 weight percent of n-methylpyrrolidone as a solvent with ethylene glycol ranging from 15 to about 45 weight percent and a stabilizer. The stripping composition preferable also contains a suitable corrosion inhibitor and a non-ionic surfactant. Also provided is a method for stripping thick negative-tone photoresists, e.g. acrylic, styrenic, maleic anhydride, and similar, from inorganic substrates by contacting the polymeric organic substance with the organic stripping BTMAH composition for a period of time sufficient to dissolve and remove said polymeric substances.

What is claimed is:  
     
         1 . A stripping composition for removing polymeric organic substances from an inorganic substrate, the stripping composition comprising about 4 to about 8 weight percent BTMAH, from about 60 to about 75 weight percent NMP and from about 20 to about 30 weight percent of a glycol, and an effective amount of a stabilizer additive.  
     
     
         2 . The composition of  claim 1  wherein the glycol is ethylene glycol.  
     
     
         3 . The composition of  claim 1  wherein the stabilizer is paraformaldelhyde.  
     
     
         4 . The composition of  claim 2  wherein the stabilizer is paraformaldelhyde.  
     
     
         5 . The composition of  claim 1  in which the stripper composition contains up to about 5 weight percent of a corrosion inhibitor.  
     
     
         6 . The composition of  claim 1  wherein the stripping composition incorporates up to about 5 weight percent of a corrosion inhibitor and a non-ionic surfactant in amounts not to exceed about 2 weight percent.  
     
     
         7 . The composition of  claim 4  wherein the stripping composition incorporates up to about 5 weight percent of a corrosion inhibitor and a non-ionic surfactant in an amount not to exceed 2 weight percent.  
     
     
         8 . The composition of  claim 3  in which the BTMAH is about 4 to about 8 weight percent, of the NMP is from about 60 to 75 weight percent and the ethylene glycol comprises about 20 to 30 weight percent.  
     
     
         9 . The composition of  claim 8  wherein the triazole corrosion inhibitor is from about 1 to 4 weight percent and the nonionic surfactant is about 0.1 to 1.4 weight percent.  
     
     
         10 . In a method for removing relatively thick film layers of a cured polymeric organic substance from an inorganic substrate the improvement characterized in that a stripping composition comprising about 4 to about 8 weight percent BTMAH, from about 60 to about 75 weight percent NMP and from about 20 to about 30 weight percent of a glycol, and an effective amount of a stabilzer additive is applied to a cured polymeric organic layer to be removed from inorganic substrate, maintaining the stripping composition in contact with said cured polymeric layer for a period of time sufficient to disengage said polymeric layer, and flushing said disengaged layer from the inorganic substrate.  
     
     
         11 . The method of  claim 10  wherein the stripping composition glycol is ethylene glycol.  
     
     
         12 . The method of  claim 10  wherein the stripping composition contains a paraformaldehyde stabilizer.  
     
     
         13 . The method of  claim 10  in which the stripper composition contains up to about 5 weight percent of a corrosion inhibitor.  
     
     
         14 . The method of  claim 10  wherein the stripping composition incorporates up to about 5 weight percent of a corrosion inhibitor and a non-ionic surfactant in amounts not to exceed about 2 weight percent.