A technique for impeding the formation of mechanical bonds between workpieces, such as semiconductor wafers, and a carrier or susceptor on which they are supported during a deposition or layer formation process, such as in epitaxial processing. In the formation of relatively thick films, greater than approximately 50 microns (50 .mu.m) thick, wafers can become mechanically bonded to the susceptor on which they are supported, and are subject to damage caused by thermal stresses during a cooldown phase of processing. In the disclosed method, the speed or direction of rotation of a rotatable susceptor is abruptly changed at least once, or periodically during processing. Slight movement of the wafers with respect to the susceptor during each rotation speed change or reversal tends to break any bonds before they can develop strength, and production yields of acceptable wafers are significantly improved.