COMMERCIAL SAPPHIRE SURFACES CONTAIN BURIED DAMAGE WHICH HAS A DELETERIOUS INFLUENCE ON SOS LAYERS GROWN THEREON.

COMMERCIAL SAPPHIRE SURFACES CONTAIN BURIED DAMAGE WHICH HAS A DELETERIOUS INFLUENCE ON SOS LAYERS GROWN THEREON. THE DEFECTS IN THE SILICON LAYERS RESULT IN A REDUCED YIELD OF DEVICES AND PERFORMANCE LIMITATIONS. MUCH OF THE DAMAGE IN THE SAPPHIRE SURFACE IS PRODUCED BY THE POLISHING STEP, WHICH EMPLOYS AN ABRASIVE PAD IN CONTACT WITH THE SAPPHIRE SURFACE. AN IMPROVED POLISHING PROCESS HAS BEEN EVALUATED WHICH DOES NOT REQUIRE CONTACT WITH THE SAPPHIRE SURFACE. AN EVALUATION OF SI FILMS GROWN ON SAPPHIRE SUBSTRATES POLISHED BY THIS NON-CONTACT PROCEDURE REVEALS THAT DISLOCATION AND STACKING FAULTS DENSITIES ARE SUBSTANTIALLY REDUCED COMPARED TO THE BEST COMMERCIAL SOS WAFERS. THE LABORATORY APPARATUS ASSEMBLED FOR THE INITIAL EXPERIMENTS IS INADEQUATE FOR PRODUCTION APPLICATIONS SINCE THE THROUGHPUT IS VERY LOW AND OPERATION REQUIRES CONSIDERABLE ATTENTION. WE PROPOSE TO EVALUATE THE FEASIBILITY OF A LARGER PRODUCTION-ORIENTEDMACHINE, TO CONDUCT DESIGN TRADEOFFS AND TO PREPARE A FINAL CONCEPTUALDESIGN OF A CAPABILITY AUTOMATED MACHINE WITH A MUTIPLE-SUBSTRATE.