Thermal and residual stresses of Czochralski-grown semiconducting material (Q1067813)

The thermal stresses during pulling and the residual stresses after pulling in a Czochralski-grown semiconducting crystal are obtained analytically by using an isotropic thermoelastic model. It is assumed that a finite cylindrical crystal is withdrawn from a melt with a constant pulling rate, and the physical properties of crystal are independent of temperature. Moreover the problem is considered to be a quasi-stationary one. Numerical results show that the Biot number is a prime factor affecting the thermal and residual stresses. The differences between the models of the finite crystal and semi-infinite crystal are described. An explanation of the experimental results is attempted.