In the 21st century, safety issues in the strained silicon industry, such as dislocation injection, should be carefully considered. This is because a microelectronic device usually contains sharp features (e.g., edges and corners) that may intensify stresses, inject dislocations into silicon, and ultimately cause the failure of the device. In this paper, critical residual stresses in various strained structures are calculated. It is confirmed that this model correctly predicts trends and the order of magnitude of critical residual stresses.