UNIFORM INTERMIXING OF QUANTUM-WELLS IN P-I-N MODULATOR STRUCTURES BYIMPURITY FREE VACANCY DIFFUSION

We present the results of an investigation of impurity free vacancy di ffusion (IFVD) post-growth treatments of p-i-n modulator structures. T he investigation is in two parts. We first establish that gallium vaca ncies (V-Ga) are produced during IFVD (by measuring the intensity of t he low temperature 1.2 eV signal from Si-V-Ga complexes) in a thick Si -doped GaAs sample. The second part of this work investigates the degr ee of intermixing of three 80 Angstrom GaAs quantum wells embedded in the intrinsic region of a p-i-n modulator at depths between 1-2 mu m f rom the surface. Photoluminescence studies on etched samples and catho deluminescence showed that no significant depth dependence occurs as a result of IFVD.