Onium compounds and methods of synthesis thereof

Abstract

New onium salt compounds and methods for synthesis of such compounds are provided. Preferred methods of the invention include (a) providing an onium salt compound comprising a sulfonate component having an electron withdrawing group; and (b) treating the onium salt compound with a halide salt to form a distinct salt of the onium compound. The present onium compounds are useful as an acid generator component of a photoresist composition.

1 - 6 . (canceled) 
     
     
         7 . A method of preparing a photoresist composition, comprising admixing a treated onium compound with a polymer to provide a photoresist composition,
 wherein the treated onium compound is obtainable by steps comprising:   (a) providing an onium salt compound comprising a sulfonate component, wherein the sulfonate component comprises an electron withdrawing group; and   (b) treating the onium salt compound with a halide salt to form the treated onium compound that is a distinct salt of the onium salt compound.   
     
     
         8 . A photolithographic method comprising: (i) applying a coating layer of a photoresist composition prepared in accordance with  claim 7  on a substrate surface; (ii) exposing the photoresist composition to activating radiation; and (iii) developing the exposed photoresist composition layer to provide a resist relief image. 
     
     
         9 . An onium salt compound, obtainable by a method comprising:
 (a) providing an onium salt comprising a sulfonate component, wherein the sulfonate component comprises an electron withdrawing group;   (b) treating the sulfonate salt with a halide salt to form a halide salt of the onium compound; and   (c) treating the halide salt of the onium compound to form a distinct salt of the onium compound.   
     
     
         10 . A photoresist comprising a polymer and an onium salt compound of  claim 9 . 
     
     
         11 . The method of  claim 7  wherein the wherein the treated onium compound is obtained by the steps.