Laser Micromachining of Semiconductor Materials

Silicon material has been extensively used in electronics, optoelectronics, and Microelectromechanical Systems (MEMS). In spite of good mechanical behavior exhibited by the silicon material, their brittleness causes difficulty in machining, which greatly affects the surface integrity of the machined parts. This demands a need for further investigations in this area for improving the material removal rate and surface integrity. Ultrashort-pulsed laser machining techniques have brought new perspectives for efficient machining of semiconductor materials in terms of surface integrity and energy consumption. In the present work, the effect of number of pulses and repetition rate at 1064 and 532 nm wavelengths of a picosecond laser has been investigated for dimensional quality and subsurface defects of holes. Further experiments were conducted using a femtosecond laser to understand the effect of repetition rate, pulse duration, pulse energy, and scanning speed on the quality of kerf surface.