Mechanisms of defect formation and growth in oxygen implanted SOI material during thermal ramping and isothermal annealing

Abstract

To understand the formation and evolution of precipitates and defects the authors have studied structural changes in SIMOX (separation by implantation of oxygen) material annealed at temperatures covering the range from lower temperature thermal ramping through high-temperature isothermal annealing. Precipitates and defects were studied with electron microscopy techniques, including high-resolution imaging. Samples annealed for 2 h at lower temperatures from 700 degrees C to 750 degrees C show no structural changes compared to as-implanted material. Samples annealed at intermediate temperatures from 800 degrees C, to 950 degrees C show a series of unusual structural changes which result in the formation of stacking faults. Initially, at 800 degrees C and 850 degrees C small, 3- to 5-nm precipitates form very close (within 10 to 20 nm) to the wafer surface and generate one or two short