Effect of pulse repetition rate on silicon wafer modification by four-beam laser interference

Abstract

This paper discusses the effect of pulse repetition rates on silicon wafer modification by four-beam laser interference. In the work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of dots, and different laser pulse repetition rates were applied to the process in the air. The results were obtained from 10 laser exposure pulses with the single laser fluence of 283mJ/cm2, the pulse repetition rates were 1Hz, 5Hz and 10Hz, the laser wavelength was 1064nm and the pulse duration 7-9ns. The results have been observed using a scanning electron microscope (SEM) and optical microscope. They indicate that the laser pulse repetition rate has to be properly selected for the fabrication of the structures of dots using four-beam laser interference.