Criterion for suppressing wafer bow in heterostructures by selective epitaxy

Abstract

One problem heteroepitaxial growth faces is the mismatch of thermal expansion coefficients. This mismatch causes bowing in the wafer during cooling down after the growth, which interferes with device fabrication especially the photolithographic processes. Selective epitaxy is found to be effective in eliminating wafer bow and it was experimentally achieved. In this work we develop a model based on basic principles of elasticity theory to predict the bow and to establish a criterion to eliminate this bow by selective epitaxy. It is found that the model is in agreement with our published experimental results in the case of selective epitaxy of GaAs on Si. © 1992.