The research on mechanical effect etching Si in pulsed laser micromaching under water

To explore further the influencing of mechanical effects on laser machining in the liquid, in the process of great-energy and short-pulsed laser irradiating matter in the liquid, the experiments of 248 nm laser etching n-Si under water were carried out. The removal mechanism of brittle material etched by mechanical effects, which is induced during high-energy and short-pulsed laser machining in the liquid, was discussed. In the paper, the approximate mechanics model of indentation fracture was used to analyze the mechanical effects for removing brittle materials of silicon when laser machining in the liquid. Based on this, a theoretical model of material removal rate was proposed; the experiment of laser machining under water was adopted to validate the model. The experimental results indicate that the removal rate of brittle material caused by shock forces is relatively great.

Research highlights▶ The removal mechanism of brittle material etched by mechanical effects was discussed. ▶ The approximate mechanics model of indentation fracture was used to analyze removal mechanism. ▶ A theoretical model for material removal rate of brittle materials was proposed. ▶ The experiment of laser machining underwater was adopted to validate the model.