| 摘要 |
PURPOSE:To obtain a semiconductor substrate having a plane of excellent flatness and dimentional precision, by providing a thin W layer on the junction surface of an Mo substrate with a semiconductor element. CONSTITUTION:A thin W layer 7 is prepared, by a chemical evaporation method, on the junction surface 6 of an Mo substrate 5 made by powder metallurgy, with an Si element 1. Evaporation is performed in such a manner that the Mo substrate is put in a reaction tube and a vaporized W compound, such as WCl6, and a carrier gas, such as H2, are introduced thereinto at a constant temperature of 800 deg.C. The thickness of the thin W layer is controlled by the density of the vaporized W compound which is introduced, the temperature of a reaction furnace, the pressure of a mixed gas and a time required for reaction. Since the thin W layer thus prepared is resistive substantially to the effect of oxidation by an outside atmosphere and that of corrosion by a treatment with an acid, the junction surface thereof with the element turns to be of high smoothness both in terms of planeness and dimentional precision, and the property thereof is stable when it is used in junction with the semiconductor element. |
