Temperature Effects on Laser Induced Damage and Accumulation in Silicon

In this paper we describe an investigation of the accumulation effect in N-on-1 laser damage to silicon at 1.06 microns. Experiments were conducted on thermally annealed samples and on samples at elevated temperatures at various pulse repetition rates. Experiments on thermally annealed samples suggest accumulation is not due to any extrinsic structural defect that could be annealed at 1000°C. Experiments involving accumulation at elevated temperatures as a function fo pulse repetition rate indicate that any defect responsible for accumulation must have a lifetime of at least 1 second at 500°C. This suggests that an extended structural defect may be involved in accumulation. Results of these experiments also support a thermal melting model for laser damage to silicon at 1.06 microns.