Chemistry of hexamethylcyclotrisilazane (HMCTS) silylation

Incorporation of organometallic compounds into conventional photoresists in a post-exposure treatment offers the advantage of utilizing familiar exposure processes while converting the imaging layers to reactive ion etch (RIE) barriers. Post-development treatment of conventional positive photoresist films with a xylene solution of hexamethylcyclotrisilazane (IIMCTS) converts the resist layer into an effective oxygen RIE barrier. Research has concentrated on two aspects of the IIMCTS silylation process. First, the chemical reactions occurring during the silicon incorporation and, second, some factors which may influence the diffusion of the 'silylating' reagent into resist films. This report will concentrate on the chemistry of the reaction between HMCTS and novolac resin.