Fabrication of 0.2 µm Fine Patterns Using Optical Projection Lithography with an Oil Immersion Lens

Fine patterns are fabricated by using optical projection lithography with both an oil immersion lens of NA=1.25 and a conventional single-layer resist. Chlorobenzene soak is used in order to remove the immersion oil and to improve the side wall profile of the resist patterns. Some samples are lightly etched by O 2 plasmas in order to remove a residual resist at the bottom of the resist patterns. Finally, it is found that a 0.18 µm fine resist pattern with a good edge definition can be fabricated. Al line and space pattern with a width of about 0.21 µm is also fabricated by lift-off technique.