| 摘要 |
PURPOSE:To obtain a mask for dry etching having excellent perpendicularity by subjecting upper resist patterns of a three-layered structure to a high temp. heating treatment after the formation thereof, thereby erasing striation and the laminated cross stripes by the influence of standing waves. CONSTITUTION:A 1st layer photoresist layer 2 is formed on an InP semiconduc tor substrate 1 and is then spin coated with a soln. mixed with orthotitanic acid and is heat treated, by which an intermediate layer 3 is formed. The upper layer photoresist film is therafter formed and is exposed by a reduction stepper to form patterns 4. The striation 5 and the laminated cross stripes 6 generated by the influence of the standing waves are erased by executing the heating treatment for 20 minutes at 170 deg.C. The intermediate layer 3 and the lower layer resist 2 are dry etched in this way, by which the mask for sharp dry etching which is free from the striation at the pattern edges is obtd. |
