Photolithographic etching of semiconductors by projected light

摘要

The etching process uses a transparent mask (10) in a projected lighting process. It produces a phase difference in the lighting, reducing the raster measurement to the minimum for structure production. One side of the mask is inclined at a given angle theta relative to the direction of the incoming beam. The other is parallel to the photoresistant layer (12) which is formed in a regular pattern. Consequently, between neighbouring sections of the inclined mask a light phase difference is produced on the formula n.d.tan theta, whereby n = the refractive index of the mask substrate, d = the raster measurement of the mask and theta = the angle of incline.