A STUDY OF DISSOLUTION CHARACTERISTICS AND ACID DIFFUSION IN CHEMICALLY AMPLIFIED DUV RESIST

The effects of dissolution characteristics and acid diffusion behavior on lithographic performance were evaluated in tert-butoxycarbonyl (t- BOC)-protected chemically amplified positive deep-ultraviolet (DUV) re sists. The resists consisted of t-BOC-protected polyhydroxystyrene as a base resin and 2,4-dimethylbenzenesulfonic acid derivative as a phot oacid generator (PAG). In particular, the line width difference betwee n an isolated line and a dense line (iso/dense bias) was investigated by changing the post-exposure bake (PEB) temperature. Asa result, clea r relationships among dissolution characteristics, acid diffusion leng th, and iso/dense bias were obtained. Moreover, suitable dissolution c haracteristics and acid diffusion length for reducing iso/dense bias w ere clarified.