Analytical Modelling of Annular Millisecond Laser-induced Damage in Silicon
J. Bi, G.-B. Chen, G.-Y. Jin and X.-H. Zhang
In this paper a two-dimensional (2-D) axisymmetric physical model to express the temperature and thermal stress in damage process of silicon plate irradiated by annular millisecond laser is presented, and analytical solutions of 2-D heat conduction equation and thermo-elastic equations are obtained using integral transform method. Then, the transient temperature fields and the thermal stress of silicon are simulated, and the locations of the maximum temperature rise and the maximum tensile stress are obtained. Finally, the melting damage threshold and the thermal stress damage threshold of silicon are investigated, and the damage threshold changing with irradiating time is discussed. Modelling results show that the damage form of silicon irradiated by annular millisecond laser is melting damage mainly.
Keywords: Annular millisecond laser, silicon, laser-induced damage, analytical modelling, Fourier heat conduction theory