Electrical characterization of InP epitaxial layers using mobility spectrum technique

The paper reports a study of electrical properties of InP layers -3 mm thick.epitaxied by MOVPE and HVPE. The technique used is the so-called mobility spectrum method in which the maxima of carrier density are determined as a continuous function of mobility. A reduced conductivity tensor RCT.adjustment allows to improve the accuracy in the determination of density and mobility values. In such layers, a high mobility channel, corresponding to the bulk material, is evidenced. However, low mobility channels are also detected and are interpreted in terms of the presence of defects n-type for MOVPE and p-type for HVPE. at the substrate–layer interface. In the case of thin epitaxied layers on insulating substrate, the classical Hall data leads to a nonsignificant mean value of mobility while mobility spectrum technique improves the understanding of electrical properties at the layer–substrate interface. q1999 Elsevier Science B.V. All rights reserved.