Optimization of nanosecond UV laser illumination for semiconductor materials (Si, HgCdTe, InSb)

ABSTRACT. We studied stages of formation of laser craters for the purpose of decreasing a defeat zone of a semiconductor material closeto laser craters. The researches were carried out using SEM and optical microscopy. This paper is devoted to results ofoptimization of the laser radiation for applications in microelectronics. The principles of optimization of a wavelength, pulseduration and repetition frequency of laser radiation are determined. The effect of the diameter of a laser spot onto theprocess of formation of a laser crater is shown. It is opinion of the authors, that the main criteria that necessarily should betaken into account when doing the laser scribing of semiconductor wafers, are as follows:Selection of a laser source wavelength with maximum coefficient of absorption in a target.The energy density in a laser spot on target must be less than threshold for the material;The time gap between pulses is determined by time of the ending of processes in the material ofthe target.The decrease in diameter of a laser beam allows maximum depth to diameter relation to be achieved.Keywords: Laser ablation, laser-material processing, semiconductor.