Alleviation of Surface and Latent Striation Problem in Some Photoresists
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
Surface and latent striations (striations which become evident when a film is thinned) are often observed when a photoresist is spin-coated from certain casting solvents. The addition of a non-ionic fluoro carbon surfactant eliminates both types of striations when added in sufficient quantity. It was found that 500 ppm of the surfactant eliminated striations in films of photoresist when a casting solvent, consisting of 90 parts cyclopentanone and 10 parts diglyme, was used. Without the surfactant, surface striations were 300 ˜ (peak-to-valley height measured by Taly-step) and latent striations were 1600 ˜ when the film loss was 10%. Little effect on the E-beam performance was observed at 10 u coul/cm2 exp. (dissolution rate and rate ratio were not changed significantly).