A Study of the Effects Laser Pulse Parameters Have on the Laser-induced Electrochemical Etching of Silicon
Y-H. Long, Y-J. Liao, X-M. Li, J-W. Yu, L-C. Xiong and T-L. Shi
Laser electrochemical etching process, which combines laser direct etching process and electrochemical etching process, is a compound etching technique. Because of the laser-induced effect, the etching process only occurs in the laser-irradiating zone and so this process can transfer pattern without mask. The experiments of micromachining silicon by laser-induced electrochemical etching were carried out. This paper adopted a 248 nm excimer laser as the light source and used KOH solution as electrolyte. Based on the experimental results, the effect of laser pulse parameters on surface morphology and etching rate in laser electrochemical etching were researched, the curves of etch rate varying with pulse parameters were given, and the reasons of etching results were analysed in detail. Therefore, laser pulse number is an effective way to control the etching depth.
Keywords: Excimer laser, pulse parameters, electrochemical etching, KOH, etch depth, silicon