Experimental tests of non-thermal effect for pulsed-laser annealing by time-resolved reflectivity and EPR measurements

Abstract

Experimental tests of non-thermal effect for pulsed laser annealing (PLA) of semiconductors have been done by means of two techniques. One is time-resolved reflectivity measurement during single 30-ps PLA of amorphous GaAs. An anomalous dynamic behavior is observed at an energy-density window, i.e., a reflectivity dip appears after the disappearance of the high reflectivity phase, concomitant with the final production of a new amorphous GaAs state. This result cannot be interpreted in terms of the simple thermal effect. The other is EPR measurement of Si samples which are implanted and then annealed by 40-ns pulsed laser. No EPR results of N donors in Si support positively a non-thermal effect, while it is difficult to explain EPR results of laser-induced paramagnetic defects only by the simple thermal annealing model.