Vapor Phase Growth of Stannic Oxide Single Crystals

Single crystals of stannic oxide, , of higher purity and with higher Hall mobility than any previously reported have been grown from the vapor using the reaction at 1250° C and 10 Torr. The stannic chloride is obtained from the reaction 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 is controlled by adding additional Cl 2 to the flow before it is introduced into the furnace; with sufficient Cl 2 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 resistivity at 300°K, and antimony‐doped n‐type crystals with resistivity, carrier concentration, and mobility of 0.1 ohm‐cm, , and 160 cm 2 /V‐sec at 300°K and of 0.1 ohm‐cm, , and 1200 cm 2 /V‐sec at 77°K have been grown, as have n‐i junctions.