SEMICONDUCTOR HOLLOW BODIES

摘要

1420388 Silicon hollow bodies WACKERCHEMITRONIC GES FUR ELEKTRONIC GRUNDSTOFFE mbH 28 March 1973 [28 March 1972] 14885/73 Heading C1A Semi-conductor hollow bodies are prepared by depositing a layer of silicon dioxide on to a substrate consisting of or coated with carbon, by combustion of a volatile silicon compound, e.g. silane, dichlorosilane, trichlorosilane, silicon tetrachloride or a mixture of two or more thereof, with H 2 in air, depositing a layer of amorphous Si on to the silicon dioxide layer by decomposing a mixture of a volatile silicon compound and excess H 2 at 600-800‹ C., depositing a layer of polycrystalline Si on to the amorphous Si layer by decomposing a mixture of a volatile silicon compound and excess H 2 at 1050-1250‹ C. and removing the resulting polycrystalline hollow body from the substrate. In embodiments described with reference to Figs. 1 and 4, respectively Si tubes and domes may be prepared. A silicon dioxide layer 25 is deposited upon carbon tube 19 or carbon body 23 (supported by quartz body 22) by burning trichlorosilane and H 2 in air. Then 5 to 20% by volume trichlorosilane and 95 to 80% by volume H 2 is introduced into chamber 14 and amorphous silicon layer 26 is deposited on silicon dioxide layer 25 by electrical heating to 600-800‹ C. of tube 19 via electrodes 17, 171 or carbon body 23 via heating spiral 24. The layers are raised to 950-1200‹ C. for 60-90 minutes. Polycrystalline silicon layer 27 is deposited by heating to 1050-1250‹ C. and then the tube 19 or body 23 is removed. Intermediate layers 25, 26 may be removed by purification-etching.