Single step quantum well intermixing with multiple band gap control for III-V compound semiconductors

We report a quantum well intermixing technique based on Ar plasma induced damage on both GaAs- and InP-based materials with single-step multiple band gap creation across a substrate. A quantum well structure with multiplewidths serves as a sensitive tool to probe the damage created by Ar plasma. The analysis reveals that the surface defects were created up to a certain depth and propagated deeper into the material upon subsequent annealing. A simple and reliable way to obtain a controlled multiple band gap was achieved by using the spatial defect modulated intermixing. Eight band gap levels were realized across a single chip of quantum well laser structure with a linear relationship to the fraction of the open area under plasma exposure. This simple approach can be implemented at a postgrowth level to a wide range of material systems to achieve multiple band gaps, suitable for photonic integration. (C) 2004 American Institute of Physics.