화학공학소재연구정보센터
Journal of Vacuum Science & Technology B, Vol.13, No.6, 2954-2956, 1995
Asymmetric Overhung Resist Profile Fabricated by Optical Lithography
We propose a new and simple fabrication technique for resist patterns of asymmetric overhung profiles. This technique uses an asymmetric blind phase edge line (AB PEL) mask and a negative photoresist which has a large absorption coefficient. The AB PEL mask has repeated chrome line patterns, called blind patterns, to reduce light intensity at large undercut overhangs of resist space. The bottom part of the resist film under the blind area is not sufficiently irradiated to become insoluble in the developer. An asymmetric overhung profile with 0.25 mu m space width at the resist top is fabricated. This profile enables fabrication of asymmetric gate recesses for field-effect transistors in compound semiconductors.