Laser drilling of single crystal silicon carbide substrates

Silicon carbide (SiC) is a wide bandgap compound semiconductor suitable for high temperature and high voltage power electronics applications due to its high electrical breakdown strength and high thermal conductivity. It also exhibits excellent metallurgical properties such as high hardness and resistance to chemical degradation. These properties make SiC processing difficult with conventional machining methods. Laser cutting, drilling and etching are promising technologies for SiC machining in advanced device fabrication. An analytic transient thermal model is developed to analyze laser drilling of SiC. The model is based on volumetric heating to account for the semi-transparent optical properties of doped SiC at the Nd:YAG laser wavelength of 1.06 µm. The results of the mathematical model are compared with experimental data pertaining to the drilling speed, hole size and the taper of the hole under different laser parameters. Laser Microfabrication Conference