ANALYSIS OF SUBSTRATE EFFECT IN CHEMICALLY AMPLIFIED RESIST ON SILICATE-GLASS

The substrate effect of chemically amplified (CA) resists on boron-pho sphorous-silicate-glass (BPSG), boron-silicate-glass (BSG), phosphorou s-silicate-glass (PSG) and non-doped-silicate-glass (NSG) has been inv estigated using a surface analysis technique. The resist pattern of a negative-tone CA resist on BPSG, PSG and BSG substrates has an undercu t profile, and that of a positive-tone CA resist on these substrates h as a footing profile. To clarify the interaction between CA resists an d BPSG, BSG, PSG and NSG substrates, the surface of these substrates w as analyzed by electron spectroscopy for chemical analysis (ESCA). It was found that there are boron oxides and/or phosphorous oxides on the surface. These oxides are considered to contribute to the undercut pr ofile of the negative resist and footing profile of the positive resis t, and to quench photo-generated acids in the resists. Further, cleani ng of the surface of a BPSG substrate with H2SO4/H2O2 is results in im provement of the pattern profile.