Analysis of temperature and thermal stress fields in pulse treatment of semiconductors

High-energy beam treatment of semiconductors presents a modern alternative to conventional technology. In pulsed processing high temperature gradients leads to high compressive therm alstresses. The thermal diffusivity of the considered semiconductors germanium and silicon decreases considerabely with temperature increase, which leads to additional heat built-up in the thermal affected zone. The considered axisymmetric thermomechanical problem consists of non-linear and nonstationary heat conduction and quasi-stationary thermoelasticity at fixed times. The temperature distribution and the thermal stresses are calculated by a hybrid Finite Difference/Finite Element method. The finite-difference and finite-element approaches use different node distributions, and the interpolation interface between to two methods transforms the values from one grid to another. The performed modeling have shown that at heating up the target to melting temperature, maximum thermal stresses on the surface of germanium exceeds values on the surface of silicon approximately on 40% .