| abstract |
The substrate is coated with a metal halide (I) and exposure with radiation of an energy higher than that corresp. to the forbidden width of (I) and a stimulation intensity higher than that needed for stimulation of 1/10th of a mol. constituent of (I). (I) (lower limit of the stimulation energy in mJ/cm2) pref. is PbI2 (10), BiI3 (7), GeIi (6), SnI2 (u0), AsI3 (9), SbI3 (9), HgI2 (9), TlI (11), SnCl2 (15), PbCl2 (15), HgCl2 (15), SnBr2 (13), PbBr2 (10) or BiBr3 (11). Used for the prodn. of very fine patterns needed for etching, vapour deposition or diffusion processes in the prodn. of semiconductor structures and for lattices, rasters, video discs etc. The process gives very fine and precise patterns. |