Microscopic and Elemental Mapping of InSbBi Substrate of Bulk Crystal Grown by VDS

III-V ternary bulk crystal (ingot) using Indium, Antimony and Bismuth as the source materials (InSb1-xBix) was grown by the vertical directional solidification (VDS) technique and the grown ingot was sliced into wafers. Further the well-polished wafers were used for the surface characterization of the grown crystal. The resistivity measurement indicated that the wafers were n-type semiconductors with the resistivity 1.00 X 10-3 ohm-cm. These wafers were lapped and polished to get mirror finish surface. After cleaning the wafers were etched by using CP4 (HNO3:HF:CH3COOH::5:3:3) and the modified CP4 (HNO3:HF:CH3COOH:H20::5:3:3:10) etchants. The microstructures and defects on the surface of the wafers (substrates) were studied using metallurgical microscope. SEM and EDAX techniques were used for the further analysis of the microstructures observed by the microscope. Most of the surface is having uniform configuration with some defects like grain boundaries, dents, black spots etc. EDAX analysis of the black spots indicate Bi rich domains. Distribution of the compositional elements was studied by elemental analysis of the surface. High resolution SEM analysis of a dent shows formation of nano-crystals of size ~ 150nm.