Pocket surface and slip defect in Si epitaxy

Slip generation in the VPE growth of Si epiwafers using a pocket susceptor is studied. Instead of forming a uniform contact, the wafer is edge-supported by discrete nodules on the pocket surface. This contact scheme causes surface damage near the wafer edge. The damage distribution is explained using the Hertz theory, which predicts a high contact stress at the onset of wafer sagging. The damage spot acts as the site for slip generation, while the extension of slip is affected by wafer distortion during growth.