Photoresist Development on Sic and Its Use as an Etch Mask for Sic Plasma Etch
CommitteeWolan, John T.
Photoresist is a light sensitive material whose physical and chemical properties change when exposed to light. Photoresist makes it possible to transfer the image of a circuit pattern directly onto a substrate. The first part of this work deals with developing a photo process using AZ 1518 and AZ P4330 positive resists on SiC substrate. The aim was to determine the optimal spin parameters, softbake time, and exposure time for these resists matching their thickness. AZ 1518 process was developed for a 1.76 um thickness and AZ P4330 for 4.3 um thickness. With the parameters obtained the resist had about 5% of difference in thickness across a wafer surface. The absence of practical wet chemical etching of SiC is the reason for the study of dry, plasma etching of SiC in this thesis. There is an interest in photoresist as an etch mask because it is cheap, easy to deposit, pattern and remove. However its ability to mask etching of materials with high bond strength like SiC is limited. This work examines its selectivity under various etching parameters and determines the effect of increase in the RF power on selectivity, SiC etch rate and photoresist etch rate.