| 摘要 |
1,136,881. Thermal reduction of silicon compounds. WESTINGHOUSE ELECTRIC CORP. 12 May, 1966 [26 May, 1965], No. 21045/66. Heading C1A. [Also in Divisions C7 and H5] Apparatus 100 for depositing Si on a substrate e.g. of silicon by thermal decomposition comprises a reaction chamber 104 containing a heater strip 136 having a core 137 of conductive material coated first with a silicide of a constituent of the core material and then with Si, the strip supporting the substrate. The core is of C, Mo, W, Ta or an alloy thereof. The core may be coated by heating in H 2 to clean the surfaces, maintaining the temperature and introducing H 2 and a halogenated silane, e.g. SiCl 4 , HSi C1 3 , SiH 2 Cl 2 , or SiI 4 , to deposit Si which reacts with the core to form the silicide layer, finally reducing the temperature when Si is deposited. Two cores 137, 139 are mounted in the chamber 104 connected together by a bridging strip 140 and to an A.C. or D.C. supply through electrodes 112, 128 and 114, 130 mounted in a water cooled Ag plated brass base 102 supporting the vessel 104. Gas inlet and outlet tubes 148, 152 pass into the vessel and a screen 154 minimizes contamination from metal parts of the apparatus adjacent the base. The cores and strip 140 are coated in situ and single crystal P or N type Si substrate placed on the heaters. The substrates are heated in H 2 to clean their surfaces and then in H 2 and HSi C1 3 to deposit epitaxial layers of Si, dopants e.g. BBr 3 may be introduced into the gas. During deposition the Si coating of the heater is transferred to the substrate and the heater is reused after etching with HC1 to remove all the Si and recoating with Si. The coated substrate forms a diode. |
