The initial stage of the reaction process forming the platinum silicide at Pt/Si (111) interfaces have been investigated by a high resolution electron microscope in both “flat-on” [1] and “cross-sectional” mode.First, platinum of 11 nm thickness was deposited on a Si (111) wafer. For observing the specimen in “flat-on” mode, the top surface and edge of the specimen were covered by paraffin and etched chemically using CP-4 reagent from backside. The specimen for observing in “cross-sectional” mode was prepared as follows. The Si wafer was cut into slips of 3mm width. After stacking 4 to 6 slips together with epoxy resin, the stacks were sliced to a thickness of 0.3-0.4mm by a diamond saw. The slices were mechanically polished to a thickness lower than 0.05mm and then thinned by Ar ion beam.The formation process of platinum silicide (PtSi) was observed in a cross-sectional specimen.
Experimental investigation of the extraction of solitons at the initial stage of the soliton formation process