EBES: A practical electron lithographic system

An electron beam exposure system (EBES) has proven to be practical and economic for generating high-quality fine-featured integrated circuit masks. It is also capable of exposing patterns directly on resist-coated silicon wafers and, when so used, is an effective tool with which to develop new semiconductor devices. EBES combines continuous translation of the mask or wafer substrate with periodic deflection of the electron beam in a raster-scan mode of exposure. Substrate position is monitored by means of laser interferometers. The strategy permits both the electronic and mechanical subsystems to work well within their limits of capability and contributes to system reliability. It also permits the system to be stepped up to higher resolution and faster exposure as brighter electron sources, more sensitive resist, and faster data processing techniques are developed.