New scanning photoluminescence technique for mapping the lifetime and the doping density: application to carbon doped InGaAs/InP layers and heterostructures

Lifetime and doping characterization of selected layers in epitaxial structures as, for example, p-doped layers encountered in the base of Heterojunction Bipolar Transistors (HBTs) is of great importance for the successful development of these devices. Various techniques exist for the evaluation of such characteristics, including time-resolved photoluminescence and Hall measurements. There is, however, lack of a single, fast, non-destructive, quantitative technique that can provide combined lifetime and doping information and that allows, in particular, spatially resolved measurements with high resolution, as well as, wafer-scale mapping evaluation. This paper addresses these issues and demonstrates the feasibility of the proposed approach by successfully applying it to carbon doped InGaAs.