Etch pits and dislocations of Ga1−xAlxAs liquid phase epitaxial layers

The etch pits of Ga1−xAlxAs are revealed by the etchant (H2O/H2O2/CH3COOH/HF) and it is verified that these etch pits correspond faithfully to dislocations using x-ray transmission topographs. The shapes of dislocation etch pits which are revealed by the etchant (1 H2O/1 H2O2/2 CH3COOH/0.5 HF) are either conical on the (100) face of Ga1−xAlxAs with x≳0.1 or pyramidal on the (100) face of Ga1−xAlxAs with x=0.05.