Diffusion in a single crystal within a stressed environment

The energetics of point defects and diffusion in a single crystal is analyzed with respect to stress in overlying or encapsulating layers. The resulting theory subsumes previous formulations of pressure and stress effects on diffusion. A key prediction is that stress on the overlayer side of the crystal boundary perturbs point defect concentrations in the underlying crystal. The effect can occur without significant strain in the crystal itself. The theory is compared with available published data on diffusion in silicon under thin strained overlayers.