Investigation of pattern wiggling for spin-on organic hardmask materials

Abstract

Semiconductor manufacturing technology is currently undergoing a transformation from immersion photolithography to double patterning or EUV technology. The resultant resist dimensional size and height shrinks will require improved pattern transfer techniques and materials. Underlayer (UL) processes which include chemical vapor deposition (CVD) and spin-on application play a very important role in various chip manufacturing integration schemes. A pattern wiggling problem during substrate etch has arisen as a critical issue when pattern dimensions shrink. CVD processes have shown better pattern transfer performance than spin-on processes but at higher cost and process complexity along with difficulty in obtaining planarization and good gap fill. Thus spin-on process development has received increased attention recently as an attractive alternative to CVD processing. In this work we focus on elucidating the mechanism of UL wiggling and have synthesized materials that address several hypothesized mechanisms of failure: hydrogen content, modulus, film density, charge control unit type and thermal resistance. UL materials with high thermal resistance additionally provide the ability to expand the applicability of spin-on approaches. Material properties and wiggle failure test results will be discussed. © 2012 SPIE.