| 摘要 |
PURPOSE:To produce a titled molding contg. less impurities at a low cost, by using a matrix for molding consisting of inorg. powder coated with a specific compact inorg. layer on the surfaces and melting semiconductor blank materials in a nonoxidative atmosphere. CONSTITUTION:A base material 2 for a matrix consisting of powder of high m. p. inorg. materials having 0.1-3mum average grain size (e.g.; quartz) and a binder is cast into a wooden pattern 1, and a metal mold 3 is inserted into the pattern 1 and is heated to 300-800 deg.C and the binder is removed, whereby a matrix 4 for molding is obtd. The matrix 4 is stored in a reaction furnace of hermetic construction and is heated to 800-1,400 deg.C; at the same time, reactive gases contg. silicon tetrachloride or hydrogenated silicon, N2 and NH3 is supplied to form a compact inorg. layer 6 having corrosion resistance and impermeability to the semiconductor melt on the surface of the matrix 4. Semiconductor blank materials 6 are packed in such matrix 4 and are heated to 1,400- 1,500 deg.C in a non-oxidative atmosphere to melt the materials 6, whereafter the materials are cooled to solidify. |
