METHOD OF FORMING PATTERNS

摘要

Method of forming patterns in which a photosensitive chalcogenide film on a substrate is exposed to pattern-defining light or accelerated particle beams, exposed portions are coated with silver, and unexposed portions are removed by gas plasma etching. For example, an amorphous chalcogenide (Se75Ge25) film (2) 1500 angstroms thick, is formed on a 2000 angstroms thick SiO2 film (1b) defined on a silicon wafer (1a) and a 80 angstroms silver layer is formed on top of this by decomposition of AgCN. Then, 150 sec. exposure is effected through a pattern mask (5), followed by 100 sec. immersion in a dilute aq. sol. of aqua regia, then 7 sec. etching with CF4 gas plasma which is produced by imposition of a 13.56 MHZ field on CF4 gas maintained at 0.5 Torr, and which removes unexposed portions (22) to leave a pattern-defining layer of silver-doped Se75Ge25 amorphous material (21) on the SiO2 film.