Resist image enhancement by UV-, soft vacuum pulsed electron beams and organometallic compounds

UV-hardening/photostabilization process is used for preventing thermal flow of resist images at high temperatures.[1] Because of high temperature stability and highly crosslinked nature of resist surfaces, UV-hardening is used for resist enhancement for reactive ion etchings of metals, high temperature sputtering, lift-off and others.[2] We like to present here multilayer resist applications using highly crosslinked resist surfaces. Because of large deep UV absorption coefficients, application of UV-hardening to thick films is limited. For thick resist films, resist stabilization by pulsed electron beams operating in soft vacuum [3] is far more efficient because of deeper penetration of electron beams of 25 KeV energy. The present technique has an advantage over a conventional CW electron source with a larger diameter, cold cathode of an ordinary metal operating in a soft vacuum with high efficiency. Exposures of resist images to organometallic compounds either in vapor phase or in solutions provide them specific RIE resistances and thermal flow resistance. © 1987.