Hardmask-less stencil mask making requires resist masks with a high aspect ratio. Singlelayer top surface imaging (TSI) and bilayer chemical amplification of resist lines (CARL) were evaluated and compared, with respect of generating irregular resist features below 180 nm in a him thickness of 850 nm. Special methods for eliminating the resolution-limiting effect of the glass transition temperature (T-g) drop are described. Optimized plasma etching conditions for both thin layer imaging (TLI) techniques were developed. Finally, results of a deep silicon etching process using the TLI resist masks are presented.