HYDROGEN INTRODUCTION AND HYDROGEN-ENHANCED THERMAL DONOR FORMATION IN SILICON

Hydrogen has been introduced from a rf plasma into Czochralski Si at 2 75-degrees-C. Most of the hydrogen is trapped near the surface where i t forms Si-H bonds, but a small fraction diffuses into the Si. This fr action enhances oxygen-related thermal donor (TD) formation rates in a diffusionlike profile during subsequent furnace anneals between 350 a nd 400-degrees-C. A hydrogen concentration that is only a few percent of the oxygen concentration is sufficient to enhance the TD formation rate, indicative of a hydrogen-catalyzed process. Maximum concentratio ns for TDs after annealing at 400-degrees-C exceed that for retained h ydrogen. A mechanism of hydrogen diffusion through oxygen traps and co rrelated hydrogen-promoted oxygen diffusion is proposed to explain the enhanced TD formation rates.