Study of Bi-level Resist System with Conductive Bottom Layer for EB lithography

抄録

We describe a new electron-beam (EB) bi-level resist system of threedimensional polysilphenylenesiloxane (TSPS) over a conductive bottom layer containing sulfonated polyaniline (SPAn). The top-layer TSPS, with a chloromethylphenylethyl (CMPE) functional group and a suitable molecular weight, is a highly sensitive negative resist without a chemically amplified system, and has a long film life. The conductive bottom layer, comprises SPAn and a crosslinker, and has excellent conductivity, a long shelf-life, and stability to solvents used for TSPS coating and development. We achieved a high resolution for 1-Gbit DRAM reticle fabrication with optical proximity correction (OPC) patterns, and significantly reduced the pattern distortion caused by the proximity effect and EB charging using this system without any data correction. Moreover, we found that the conductive resist system can be used to reduce the plasma etching damage of thin gate oxide when used in MOS-LSI device fabrication.