Silylation Processes for 193-nm Excimer Laser Lithography

摘要

A silylation process for novolac-based resins was developed which results inpositive-tone imaging. This process is based on 193-nm-induced crosslinking followed by a low temperature silylation step. Novolac resin without diazoquinone additives may also be used as positive-tone resists. Typical conditions were exposure to dimethylsilydimethylamine vapor at 10 Torr for 1 minute at 100 C. This incorporates silicon in the uppermost 100 to 1000 nm of the film, depending on the resist. Etch selectivities in a 10 mTorr oxygen reactive ion etching plasma with a bias voltage of -200 V were typically 30:1. Resolution below 0.3 micron has been demonstrated with this technique.