Negative electron beam resist poly

Poly(glycidyl methacrylate) (PGMA), a well-known negative electron beam resist first reported by Hirai et al. (55), actually functions as a positive-tone resist upon DUV exposure (Table 3.1) (56). The epoxide functionality responsible for cross-linking under electron beam exposure does not absorb in the DUV region, and the response of PGMA to DUV radiation is determined by the absorption due to the n — tt transition of the carbonyl chromo-... 

Figure 62.0 Poly(olefin sulfone) resistant to plasma etching 6.43.2 Negative Electron-Beam Resists...

Typical resists include cyclized polyisoprene with a photosensitive crosslinking agent (ex bisazide) used in many negative photoresists, novolac resins with diazoquinone sensitizers and imidazole catalysts for positive photoresists, poly(oxystyrenes) with photosensitizers for UV resists, polysilanes for UV and X-ray resists, and polymethacrylates and methacrylate-styrenes for electron-beam resists (Clegg and Collyer, 1991). Also note the more recent use of novolac/diazonaphthoquinone photoresists for mid-UV resists for DRAM memory chips and chemically amplified photoacid-catalysed hydroxystyrene and acrylic resists for deep-UV lithography (Choudhury, 1997). 

The surface photo absorption for contrast enhancement (SPACE) process has been recently reported for use with a negative-working electron-beam resist (42). By addition of a controlled UV-flood exposure step, enhancements in both contrast and sensitivity of MRS RD2000N resist, a negative working resist composed of poly(p-hydroxystyrene) and 3,3 diazido-diphenylsulfone, have been obtained. However, its application is iimited to negative working resists. 

---