Electron lithography mask manufacture.

摘要

A layer of electron sensitive resist (13) on a semiconductor substrate (12) is exposed to a patterned electron beam emitted from an erasable photocathode mask (6, 9) in an electron image projector (5). The mask is formed from a transparent, e.g., quartz, plate (6) on which is provided a layer (9) of caesium iodide or other photoemissive material. A photoemissive pattern is defined in layer (9) by selective direct exposure to a beam of photons, electrons or ions preferably in an evacuated carbon-containing environment whereby the photoemission of the exposed areas of the caesium iodide is lowered. Alternatively using a beam of charged particles with a relatively high current density the exposed parts of the caesium iodide are actually removed by evaporation. In both cases, the patterned caesium iodide can be removed by rinsing in water and the transparent plate (6) can be reused with the same or different photoemissive pattern.