Product Code: ICAL09_M1005

Surface Stress Modification in Silicon Carbide by Laser Ablation
Authors:
Ronald Jacobsen, Mound Laser & Photonics Center, Inc.; - USA
Joseph Randi, Penn State Electro-Optics Center; Freeport Pa PA USA
Sarah Bertke, Mound Laser & Photonics Center, Inc.; Miamisburg OH USA
Presented at ICALEO 2009

We report the use of short pulse laser ablation as a technique for mitigation of near surface stress and damage in SiC. Conventional machining, grinding or polishing of SiC renders a damaged surface layer of depth approximately equal to the final peak-to-valley roughness. This damage layer is comprised of compressive stress and represents a threat to the integrity of the material as sites for crack initiation. However, observations of the Twyman Effect of disk shaped samples suggest that laser ablation can remove the stress layer and substantially mitigate surface damage. Interferometry and Raman spectra data will be presented in support of this claim, along with comments on technique and applications.