Integration of broken-gap heterojunction InAs/GaSb Esaki tunnel diodes on silicon

Abstract

This study entails a comparison of the broken-gap InAs/GaSb heterojunction system on two different substrates, including Si and native GaSb as a control. Through the use of different integration schemes such as AlSb and SrTiO3 buffer layers, GaSb was grown on miscut Si substrates using solid-source molecular beam epitaxy. The InAs/GaSb p+-i-n+ heterostructures were grown on the GaSb/Si virtual substrates and compared in terms of their surface morphology and crystalline quality. Esaki tunnel diodes were fabricated, and their performance compared across the different integration platforms. The control sample shows the best peak current density of 336 kA/cm2 and a conductance slope of 274 mV/decade compared to the broken-gap junction on SrTiO3/Si and AlSb/Si virtual substrates. These results show the possibility of integrating the InAs/GaSb system in ultralow power tunnel field-effect transistors logic applications with the cost-effectiveness and maturity of the silicon technology.