Misfit Dislocation Sources at Surface Ripple Troughs in Continuous Heteroepitaxial Layers

The present work examines ordered surface ripple arrays exhibited by continuous epitaxial InGaAs on GaAs and, for the first time, demonstrates directly that ripple trough locations are sources for misfit defects at the heteroepitaxial interface. Defect nucleation can take place due to the enhanced stress at such troughs. The first stress-relieving defects observed to form are faulted dislocation half-loops on inclined {111} planes.