Formation of Silicon‐on‐Insulator Structures by Implanted Nitrogen

Abstract

The formation of a buried by high dose nitrogen ion implantation to form a silicon‐on‐insulator (SOI) structure is studied by transmission electron microscopy (TEM) and by secondary ion mass spectroscopy (SIMS). Silicon wafers are implanted with a dose of at an energy of 160 keV at wafer temperatures of 400°, 500°, and 600°C. The wafers are subsequently annealed at 1200°C for 2h to form the buried silicon nitride layer. Both the as‐implanted and postannealed microstructures are examined as a function of the implant temperature by TEM cross‐sectional analysis. The microstructures of implanted wafers annealed for intermediate times are also examined to elucidate the development of the final microstructure. The as‐implanted nitrogen profile and its redistribution during subsequent annealing at 1200°C are studied by SIMS.