Influence of MBE (Molecular Beam Epitaxy) Growth Temperature on GaAs/AlAs Resonant Tunneling Structures.

摘要

Double barrier resonant tunneling diodes (RTDs) have attracted a great deal of interest both as potential sources of microwave power and for study of the fundamental physical mechanisms which underlie the resonant tunneling process. Double barrier Gallium arsenide/Aluminum arsenide tunneling structures with typical 2.5:1 room temperature peak-to-valley current ratios are examined using Deep Level Transient Spectroscopy. Deep level trap concentrations are found to be much higher in samples grown at 550 C compared to those grown at 650 C. For devices grown at 550 C, an impedance switching effect due to a high concentration of deep levels is observed. The peak-to-valley ratio of the tunneling devices is largely unaffected by the growth temperatures in this range, indicating that higher growth temperatures can be employed to grow resonant tunneling diodes than previously suggested in the literature. Molecular beam epitaxy; Reprints. (aw)