EFFECT OF TEMPERATURE-VARIATIONS IN THE POSTEXPOSURE PROCESSES OF OPTICAL LITHOGRAPHY

The effects of developer temperature and post-exposure bake (PEB) in p hotoresist processing are investigated. Results are presented in terms of their computer simulation parameters using the Mack development mo del and show that, for the resist/developer system used, the values of R(max) and n increase with developer temperature, whilst m(th) change s only when the PEB step is varied. Increasing the PEB temperature red uces all 3 parameters. Practically, these results bring about an impro vement in resolution with increasing developer temperature but a degra dation as PEB temperature increases. The optical proximity effect know n as dense/isolated offset can be eliminated by careful selection of a n intermediate development temperature. These results reported improve the correlation between practical and simulated results and may sugge st process changes which may enhance performance in production conditi ons.