Advances in photoreflectance characterisation of photonic (resonant‐cavity) and transistor epiwafers

Advances in the application of non-contact photoreflectance (PR) spectroscopy to the characterisation of epiwafer device materials are presented. The study examines both vertical cavity surface emitting laser (VCSEL) and heterojunction bipolar transistor (HBTs) device structures. Emphasis is placed on the technologically important applications of VCSEL device material characterisation, for which PR offers the only true non-destructive testing capability, as well as upon the measurement of electric fields in device epiwafers for rf application transistors such as HBTs. This paper demonstrates the application of non-destructive and rapid techniques for evaluation and control of compound semiconductor materials for both VCSEL and HBT technology.