Anomalous growth temperature dependence of electrical properties of InP-based pseudomorphic resonant tunneling diodes grown by molecular beam epitaxy.

The effects of growth temperature on the negative differential resistance characteristics and the epitaxial layer structure of pseudomorphic In_0.53Ga_0.47As/ AlAs/InAs resonant tunneling diodes (RTDs) grown by molecular beam epitaxy have been studied. For RTDs with a symmetric structure and with an InAs subwell layer thinner than an estimated critical thickness, asymmetrical current-voltage characteristics were observed at growth temperatures below the critical temperature of 410°C, though good symmetric characteristics were obtained at higher temperatures. Examination of the RTD structures by transmission electron microscopy and atomic force microscopy revealed that three-dimensional growth of InAs at lower temperatures degrades the RTD structures, resulting in the asymmetric characteristics.