ALL DRY CVD-BASED RESIST FOR ADVANCED LITHOGRAPHY PROCESSES

摘要

With 248 nm lithography being used to obtain features as small as 0.15 μm in mass production, 193 nm exposure tools will only be used for the 0.13 m generation and beyond. Currently, much work is focused on the optimization of single layer 193 nm resist materials to obtain the required resolution, adhesion and plasma etch resistance. Another potential solution is to use thin layer imaging resists, in bi-layer or top surface imaging schemes. A photosensitive material obtained by plasma enhanced chemical vapor deposition of methylsilane or dimethylsilane (called CVD resist) can provide an all dry high resolution photolithographic process, useful both at 248 and 193 nm. In this paper, we describe the properties of CVD resist films. Photolithographic studies of PPMS and PP2MS at 248 and 193 nm demonstrate resolution close to the limits of the exposure tools. The most serious remaining issue involves difficulties in achieving acceptable cross wafer critical dimension (CD) control. The important mechanisms involved in the dry resist process are analyzed.