| 摘要 |
PURPOSE: To improve electric characteristics of a semiconductor element, by covering a conducting layer with a nitride layer before annealing when conductive silicide is formed. CONSTITUTION: The surface of an Si substrate 17 is isolated with SiO2 11, 13, a poly Is 25 is overlapped on the SiO2 21, and a pad 23 and an Si 27 are selectively formed. The pad 23 and the substrate 17 are covered with an SiO2 , and SiO2 spacers 33, 35 are formed on the periphery of the pad 23 by directional etching. Ion implantation and extruding are performed, and a source 29 and a drain 31 are formed. After a Ti 37 is vapor-deposited, a TiN 39 is reactively sputtered without breaking a vacuum. Annealing is performed, a uniform TiSix 41 is formed, and conducting layers 43, 45 of Is compound are formed on the source and the drain. The layer 41 is etched and eliminated with liquid of H2 SO4 +H2 O2 and annealed, and the layers 43, 45 and 47 are converted to TiSix layers 49, 51 and 53. By this constitution, TiSix layers which are smoother and thicker than the conventional ones are formed, and hardly affected by adverse influence of impurities, so that electric characteristics can be improved.
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