CAPACITANCE-VOLTAGE PROFILING OF MULTIQUANTUM-WELL STRUCTURES

A relatively simple procedure for calculation of the capacitance-volta ge (C-V) concentration profile N-CV(z) of a multiquantum well (MQW) st ructure has been derived. The dependence of a separate C-V concentrati on peak on the temperature and the, period of the MQW structure is con sidered. The analysis has been carried out for a regular MQW structure with a homogeneous lateral doping in every well and is restricted to the temperature range for which the effect of charge centroid shifting in QWs on the measured C-V concentration profile can be taken to be n egligibly small. Comparison of the theoretical results with experiment al data obtained for GaAs/AlGaAs MQW structures has shown that the rel evant equations describe qualitatively the main features of the experi mental curves. Some discrepancy has been observed with a weaker temper ature dependence of the extreme values of the experimental N-cv(z) dep endence at the maximum and minimum points. This may be ascribed to lat eral fluctuations of the electron concentration occurring in the QWs o f our samples. (C) 1997 Elsevier Science Ltd.