Exploration of a low-temperature PEALD technology to trim and smooth 193i photoresist

摘要

In this work, we explore the performances of a low-temperature PEALD technology used to trim/clean/smooth and reshape ArF photoresist lines that could subsequently receive an in-situ spacer deposition required to build up any SAxP grating. Different gas mixtures (02, N2, H2, Ar and combinations) are evaluated on both blanket and patterned wafers. Trim rate, line profile, surface roughness and chemical modification are characterized using ellipsometry, Fourier transform infrared spectroscopy and atomic force microscopy. The photoresist line roughness is measured from top down SEM imaging and the different contributors to the roughness determined from a Power Spectral Density (PSD) analysis. Few results obtained on EUV photoresist blanket wafers using similar plasma treatments will also be briefly presented.