Process for low k dielectric plasma etching with high selectivity to deep uv photoresist

Abstract

A method of forming a microelectronic structure and its associated structures is described. That method comprises forming and patterning a deep uv resist layer on a substrate, etching the substrate in a plasma generated from a gas comprising a carbon to fluorine ratio from about 1:1 to about 2:3 to form substantially vertical sidewalls in the deep uv resist layer.

1 . An intermediate product comprising: 
 a trench in a substrate, wherein a deep uv resist layer is disposed on a first surface of the trench, and wherein the deep uv resist layer comprises a sidewall that is substantially vertical and comprises a polymer on the sidewall; and    a bottom width of the trench wherein the ratio of the bottom width to a top width of the trench is about 1:1.    
   
   
       2 . The intermediate product of  claim 1  wherein the deep uv resist layer comprises a sidewall angle that is from about 85 to about 90 degrees.  
   
   
       3 . The intermediate product of  claim 1  wherein the bottom width of the trench is from about 80 to about 90 nm.  
   
   
       4 . The intermediate product of  claim 1  wherein the deep uv resist layer is between about 2,100 to about 3,000 angstroms in thickness.  
   
   
       5 . The intermediate product of  claim 1  further comprising a trench sidewall, wherein the trench sidewall comprises has a low k dielectric layer that comprises a dielectric constant below about 4.  
   
   
       6 . The intermediate product of  claim 1  wherein the low k dielectric layer comprises a material selected from the group consisting of carbon doped oxide, organic polymers such as a polyimide, parylene, polyarylether, organo-silicone, polynaphthalene, polyquinoline, or copolymers thereof, spin on glass materials, either doped or undoped, and porous materials such as xerogels and others that include templated pores.