InyGa1−yAs/InyAl1−yAs resonant tunneling diodes on GaAs

Resonant tunneling diodes are fabricated using InyGa1−yAs/InyAl1−yAs on GaAs substrates for the first time. The devices showed increasing peak current density as the In content was raised from 0 to 0.3, which is shown to be consistent with the Γ valley being the predominant transport mechanism at the tunneling resonance. Devices with y=0.2 showed an average peak to valley current ratio of 4.2 at room temperature, versus 3.3 for y=0. The decrease in the peak to valley current ratio is attributed to a decreased tunneling component in the X valleys of the In0.2Al0.8As barrier layers. Devices with y=0.3 show room-temperature peak to valley current ratios of approximately 2.5; the increased valley current is attributed to interface roughness scattering and other effects.