Physics of novel InAs/AlSb/GaSb resonant interband tunneling structures

A resonant tunneling diode consists of a number of abrupt layers of epitaxially grown heterojunctions, usually in III/V semiconductors, with the material composition of the individual layers chosen to create a double barrier structure in the conduction (or valence) band of entire system. As the layer thickness approach the de Broglie wavelength of the electrons in the system, the tunneling probability will be selectively enhanced at certain energies causing a peaked I(V) characteristic. Resonant interband tunneling devices differ from conventional resonant tunneling diodes in that the confined states, accessible to electron (or hole) transport lie in the valence (or conduction) band rather than the conduction band.; This work examines the details of the interband tunneling process in InAs/AlSb/GaSb structures. A simple model of resonant tunneling based on a density of states argument including magnetic field effects is presented. Experimental results from p-type well InAs/AlSb/GaSb/AlSb/InAs structures are presented. The data show that tunneling occurs through multiple subbands, including both light-hole and heavy-hole like subbands. Structures which exhibit both intraband and interband tunneling are investigated. It is shown that the placement of an AlSb tunnel barrier can greatly influence the tunneling characteristics.; Application of resonant tunneling diodes, by means of a simple switching block, to compressed functionality circuits is demonstrated in a binary and a ternary adder circuit. Also, the modification of the turn-on characteristics of a tunneling hot electron transfer amplifier is demonstrated.