High quality silicon-on-insulator structures have been formed with dislocation densities in the top silicon layer below 104 cm -2 by oxygen implantation and one-step annealing at 1300 °C for 6 h. Careful control of the implantation conditions is required in order to produce a high density of cavities in the top silicon layer. These cavities provide a stress-free sink for silicon and oxygen interstitials, reducing the point-defect supersaturations and, therefore, the nucleation and growth of oxide precipitates and dislocation loops. They also provide an internal surface which blocks free propagation of dislocation loops to the surface avoiding the formation of threading dislocations. With continued annealing, both the cavities and the oxide precipitates eventually dissolve, leaving a high quality silicon surface layer with a very low dislocation density.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)