INVESTIGATION OF RESIST PATTERN DEFORMATION IN CHEMICAL AMPLIFICATIONRESISTS ON SINX SUBSTRATES

This paper describes the pattern deformation in chemical amplification resists on SINx substrates. Pattern deformation was observed not on t he Si substrates, but on the Sin(x), substrates, even for a thin film of 1.2 to 1.5 nm depth. To clarify the resist-substrate interaction, t he substrates were analyzed by attenuated total reflection Fourier tra nsform infrared spectroscopy (FTIR-ATR) and X-ray photoelectron spectr oscopy (XPS). From those analyses, the surface Si-OH group was found t o be an important factor contributing to pattern deformation. The Si-O H group on Si is not affected by the acid generated in the resist duri ng exposure. However, tile protected Si-OH group on SiNx, is de-protec ted by the acid, and the unprotected Si-OH group on SiNx acts as an ac id trap. Moreover, Si-OH groups are sites for the resist residue forma tion. Therefore, the SI-OH group on a SiNx substrate is found to cause the pattern deformation.