Analysis Of The Thermal Effect Of The Semiconductor Surface Rrradiated By Pulse Laser

The interaction between laser and materials make the temperature rise, and cause the heat diffusion, heat expansion and the change with thermal effect, thus leading to the change of the state and structure of the material. This rule can be used to laser processing and heat treatment. The material's absorption of laser energy is related intimately to laser's parameters variation besides being related to the material's property. This thesis focuses on the influence, caused by parameters variation of the laser pulse, on the thermal effect of semiconductor material during pulse laser irradiation. Starting from heat conduction equation, considering the physical model and utilizing the Mathematica, it simulates the temperature distribution on the surface of semiconductor during irradiation of ultra-short and long pulse laser. The following are the main achievements:1.Considering the parameters of laser pulse including laser wavelength, beam radius, laser spatial profile, laser energy, and irradiation time, and utilizing the numerical of implicit finite difference method, it simulates the distribution of the temperature field on the surface of GaAs with 1-D heat conduction equation as calculation model. It analyses and concludes the failure mechanism of pulsed laser acting on semiconductor material. The effect of heat conduction ought not to be ignored during long pulse acting on the material.2.Using implicit finite difference method it performs the numerical solution on the physical model of rate equation and double-temperature equation. The numerical simulates the temperature rise of semiconductor material during femto-second laser irradiation. It highlights the influence on the temperature rise caused by different laser parameters such as laser wavelength, pulse interval, pulse energy and pulse widthThe results show that the power density of the laser pulse has a direct influence on the quantity of the laser energy adoption of the unit area on the surface of the material. This decides the temperature rise. The laser pulse width has more influence on the temperature rise for its more influence on the power density; laser wavelength also has a greater influence on the temperature rise because absorption coefficient of the material is intimately related to the wavelength of incident light.