VAPOR PHASE GROWTH OF STANNIC OXIDE SINGLE CRYSTALS

Single crystals of stannic oxide, SnO2, of higher purity and with higher Hall mobility than any previously reported have been grown from the vapor using the reaction [FORMULA OMITTED] at 1250°C and 10 Torr. The stannic chloride is obtained from the reaction [FORMULA OMITED] which is performed in an external reactor and electrical doping is achieved by adding the desired dopant materials to tin charges in parallel doping reactors. The growth rate of the SnO2 is controlled by adding additional Cl2 to the SnCl4 flow before it is introduced into the furnace; with sufficient Cl2 the crystals can also be etched. Important to the furnace design is a gas injection nozzle which eliminates growth immediately where the gases enter the furnace. Undoped crystals of 6 x 105 ohm-cm resistivity at 300°K, and antimony-doped n-type crystals with resistivity, carrier concentration, and mobility of 0.1 ohm-cm, 4 x 1017 cm-3, and 160 cm2/V-sec at 300°K and of 0.1 ohm-cm, 6 x l016 cm-3, and 1200 cm2/V-sec at 77°K have been grown, as have n-i junctions. © 1969, The Electrochemical Society, Inc. All rights reserved.