Abstract
The substrate effect of chemically amplified (CA) resists on boron-phosphorous-silicate-glass (BPSG), boron-silicate-glass (BSG), phosphorous-silicate-glass (PSG) and non-doped-silicate-glass (NSG) has been investigated using a surface analysis technique. The resist pattern of a negative-tone CA resist on BPSG, PSG and BSG substrates has an undercut profile, and that of a positive-tone CA resist on these substrates has a footing profile. To clarify the interaction between CA resists and BPSG, BSG, PSG and NSG substrates, the surface of these substrates was 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 profile of the negative resist and footing profile of the positive resist, and to quench photo-generated acids in the resists. Further, cleaning of the surface of a BPSG substrate with H2SO4/H2O2 is results in improvement of the pattern profile.