This project addresses the generation and multiplication of dislocations during the growth of cubic, cylindrical crystals of Silicon, Gallium Arsenide, and Indium Phosphide which are pulled from the melt by the Czochralski or the liquid-encapsulated- Czochralski method. Emphasis in on the computation of thermal stresses during high temperature deformation. Three major effects will be studied: 1)the shape of the solid-liquid interface between the melt and crystal, whose control may greatly reduce the resulting thermal stresses, 2)the crystalline anisotropy in relation to the direction of crystal growth, whose proper choice may minimize the resulting dislocation density for a given amount of crystalline anisotropy, and 3)dislocation generation and multiplication by using high temperature inelastic constitutive laws which treat the dislocation density as an internal variable and allow for its microstructural evolution. New qualitative and quantitative understanding of fundamental processes important to bulk single crystal growth in semiconductors is anticipated from this project; the results also have technological relevance to the microelectronics industry.
