Thermal Stresses in the Bulk and Epitaxial Growth of III-V Materials.

Large temperatures gradients and substantial differences in thermal expansion coefficients are among the major factors for thermal stress generation in many materials systems. The field of electronic materials provides striking illustrations with regard to the role of thermal stresses in crystal growth. In this paper we treat two important examples that are (1) the stresses induced by severe radial temperature gradients prevalent in the standard liquid encapsulation Czochralski (LEC) growth of III-V compounds and (2) the stresses introduced upon cooling in a composite structure comprising one or more thin epitaxial layers deposited on a thick single crystal substrate with grossly mismatched thermal expansion coefficients.