Pseudomorphic high electron mobility heterostructures with extremely high conductivity using Te as n-type dopant by low-pressure metal organic chemical vapor deposition

Abstract

Modulation-doped AlxGa1−xAs/InyGa1−yAs/GaAs single-quantum-well structures have been grown by low-pressure metal organic vapor phase epitaxy and characterized by Hall, C-V measurements, and photoluminescence spectroscopy. The use of tellurium instead of silicon as an n-type dopant for AlxGa1−xAs increases the electron concentration without decreasing the electron mobility. High free-electron concentrations of ns=7.5×1012 cm−2 (300 K) and ns=3.7×1012 cm−2 (77 K), and Hall mobilities of μ=5470 cm2 (V s)−1 (300 K) and μ=24 600 cm2 (V s)−1 (77 K) were obtained. The high concentration and mobility product of the channel: nsμ=4.1×1016 (V s)−1 at 300 K and nsμ=9.1×1016 (V s)−1 at 77 K, makes it a preferred choice for high-speed applications.