Electron beam induced chemical modification of amorphous chalcogenide–metal bilayers and its application

Metal migration and surface modification have been observed in metal-doped amorphous arsenic and antimony-based chalcogenide systems such as As2Se3 and Sb2S3 under the irradiation of an electron beam. Surface expansion of the order of 5– 35% of the film thickness has been observed by applying 5–30 kV electron accelerating voltages. This electron beam induced surface modification has been employed to produce submicron and nanometre dimensional patterns which will have applications in single stage processing of X-ray masks fabricated on an X-ray transparent silicon nitride (Si3N4) membrane. Masks with a silver deficient trough-like structure have been obtained at lower accelerating voltages (5–10 kV). Silver-rich protruding structures were obtained at higher accelerating voltages (15–30 kV). These two types of masks exhibit a different X-ray absorption behaviour by comparison with the regions unexposed to the electron beam.