Effect of Intermediate Thermal Processing on Microstructural Changes of Oxygen Implanted Silicon-on-Insulator Material

Abstract

ABSTRACTThe microstructural changes in oxygen implanted silicon-on-insulator material (SIMOX) at intermediate annealing steps and the changes by rapid thermal annealing (RTA) were studied with transmission electron microscopy. Defects found in as-implanted SIMOX, including multiply faulted defects, short stacking faults, and {113} defects, were all removed in anneals from 900°C to 1100°C. The threading dislocations in annealed material form at these temperatures during thermal ramping. RTA shows that the microstructure is significantly influenced by the ramp rate. The very high ramp rate in RTA results in very flat interfaces and a buried oxide layer with no Si islands, but significantly increases the defect density. Overall, the results show that intermediate thermal processing steps strongly affect the final microstructure of SIMOX material.