Low Temperature Flux Growth of 2H-SiC and β-Gallium Oxide

Abstract

We present brief overview of our study on the low temperature flux growth of two very important novel wide bandgap materials 2H-SiC and β-gallium oxide (β-Ga₂O₃). We have synthesized and grown 5mm to 1cm size single crystals of β-gallium oxide (β-Ga₂O₃). We used a flux and semi wet method to grow transparent good quality crystals. In the semi-wet method Ga₂O₃ was synthesized with starting gallium nitrate solution and urea as a nucleation agent. In the flux method we used tin and other metallic flux. This crystal was placed in an alumina crucible and temperature was raised above 1050 ºC. After a time period of thirty hours, we observed prismatic and needle shaped crystals of gallium oxide. Scanning electron microscopic studies showed step growth morphology. Crystal was polished to measure the properties. Bandgap was measured 4.7eV using the optical absorption curve. Another wide bandgap hexagonal 2H-SiC was grown by using Si-Al eutectic flux in the graphite crucible. We used slight AlN also as the impurity in the flux. The temperature was raised up to 1050C and slowly cooled to 850C. Preliminary characterization results of this material are also reported.