Czochralski growth of gallium indium antimonide alloy crystals

Attempts were made to grow alloy crystals of {dollar}rm Gasb{lcub}1-x{rcub}Insb{lcub}x{rcub}Sb{dollar} by the conventional Czochralski process. A transparent furnace was used, with hydrogen purging through the chamber during crystal growth. Single crystal seeds up to around 2 to 5 mole % InSb were grown from seeds up to around 1 to 2 mole % InSb, which were grown from essentially pure GaSb seeds of the (111) direction. Single crystals were grown with InSb rising from around 2 to 6 mole % at the seed ends to around 14 to 23 mole % InSb at the finish ends. A conical reflector was installed above the melt and coaxially around the growing crystal to help the crystal grow monocrystalline.; Floating crucible technique that had been effective in reducing segregation in doped crystals, was used to reduce segregation in Czochralski growth of alloy crystals of {dollar}rm Gasb{lcub}1-x{rcub}Insb{lcub}x{rcub}Sb.{dollar} Crystals close to the targeted composition of 1 mole % InSb were grown. However, difficulties were encountered in reaching higher targeted InSb concentrations. Crystals around 2 mole % were grown when 4 mole % was targeted. It was observed that mixing occurred between the melts and render the compositions of the melts and hence the resultant crystal unpredictable. The higher density of the growth melt than the replenishing melt could have triggered thermosolutal convection to cause such mixing. It was also observed that the floating crucible stuck to the outer crucible when the liquidus temperature of the replenishing melt was significantly higher than that of the growth melt.; The homogeneous {dollar}rm Gasb{lcub}1-x{rcub}Insb{lcub}x{rcub}Sb{dollar} single crystals were grown successfully by pressure-differential technique that a quartz tube was separated into an upper chamber for crystal growth and a lower chamber for replenishing. The melts were connected by a capillary tube to suppress mixing between them. A constant pressure differential was maintained between the chambers to keep the growth melt up in the growth chamber. The method was first tested with a low temperature alloy {dollar}rm Bisb{lcub}1-x{rcub}Sbsb{lcub}x{rcub}.{dollar} Single crystals of {dollar}rm Gasb{lcub}1-x{rcub}Insb{lcub}x{rcub}Sb{dollar} were grown with uniform compositions up to nearly 5 mole % InSb.