Vapor development of poly(olefin sulfone) resists

Poly(2‐methyl pentene‐1) sulfone undergoes scission followed by rapid chain depolymerization when irradiated with 5‐20 kV electrons. Several parameters which affect the rate of this process, termed vapor development, were evaluated, viz., molecular weight, dose rate, temperature, accelerating voltage and film thickness. While it was never really possible to remove 100 percent of the film, it was possible to remove > 99 percent at reasonably low doses (∼ 10−6 coul/cm−2) using high temperatures (∼ 100°C) and low accelerating voltage (5 kV). Some lithographic details of this process are also described.