Molecular-beam epitaxial growth of AlGaAs/(In,Ga) As resonant tunneling structures

Abstract

We have developed a routine molecular‐beam epitaxial (MBE) growth technique to prepare room temperature operating AlGaAs/(In,Ga)As resonant tunneling diode (RTD) structures. To grow these structures the substrate temperature, growth rate, and Si‐dopant profile were optimized in terms of the temperature dependent I–V characteristics of the RTDs. When a slow growth rate, two substrate temperatures, graded Si doping, and undoped spacer layers were combined, a 1.75:1 peak‐to‐valley ratio was achieved at room temperature in the AlGaAs/GaAs RTD structures. As a different approach, the AlGaAs barriers were replaced by all‐binary AlAs/GaAs superlattices layers in order to reduce alloy scattering and a 1.8:1 peak‐to‐valley ratio was obtained. Also, for the first time, resonant tunneling through an AlGaAs/InGaAs strained layer structure was achieved up to room temperature.