Numerical Simulation and Experimental Investigation of ps Pulsed Laser Modification inside 4H-SiC Material

Abstract

Silicon Carbide (SiC) is the predominant substrate material for optoelectronic-integrated devices. However, it challenges the wafer-slicing process because of its high hardness, brittleness, and other material characteristics. Laser processing has gained prominence as the primary method, leveraging its merits of high efficiency, precision, and micro-destructiveness. In this study, a finite element method is applied to calculate the temperature field distribution resulting from the electric field of a Gaussian beam. The simulation considers laser propagation inside 4H-SiC, non-linear absorption, and spherical aberration induced by the refractive index of the material. The influence of laser pulse energy and focusing depth are considered. The results indicate that the modification depths decrease with the increasing focusing depth. With the increase of laser pulse energy, the depth of the modification layer increases continuously. Moreover, an experimental setup has been devised to furnish valuable references in validating the proposed model.

Keywords

• picosecond pulsed laser
• laser modification
• SiC material
• numerical simulation
• electric field
• temperature field