Soft vacuum, pulsed electron-beam hardening of lithographic polymers

A 25 kV pulsed electron beam was used to harden 0.5-3.0//m thick4Z-type, MacDermid, and polyamic acid (PMDA 4- ODA) resist patterns. The resist profiles are stable against high-temperature treatment that ranges between 200–350 °C. The short pulse —100 ns, electron beams employed in resist hardening are produced from a cold cathode in 30–50 mTorr air by discharging energy stored in a 7.5 nF capacitor producing a dose/pulse — 1 μC/cm2 at the processed surface. Comparisons with conventional hardening methods using ultraviolet emission from a high-pressure mercury lamp, a windowless, vacuum ultraviolet (VUV) lamp, and low-energy electron emission from a cw source are also made. © 1988, Materials Research Society. All rights reserved.