Highly etch selective spin-on bottom antireflective coating for use in 193 nm lithography and beyond

Abstract

Extending 193nm lithography to well below 100 nm resolution will depend on high NA tooling coupled with thin resist processing. Semiconductor manufacturing uses BARC's (Bottom Antireflective Coating) based on organic spin coatable polymers, to improve the resolution by absorbing light that otherwise will be reflected back into the resist. However, the use of organic BARC's for patterning sub 100nm features will be limited due to poor etch selectivity to the photo resist. IBM has developed a new class of silicon containing polymers that can function as planarizing BARC's. These materials show an etch selectivity to the photo resist in excess of 3:1 in fluorocarbon based ARC-open RIE chemistry. The hardmask properties of these materials for oxide open etches are similar to typical resists. Furthermore these materials can be implemented like organic ARC's and are stripped in resist strips available in manufacturing. Basic materials characterization data, optical tunability, lithographic performance with different resists, process window data, and complete integration schemes will be presented.