High conductivity modulation doped AlGaN/GaN multiple channel heterostructures

A methodology for the design of modulation doped AlGaN/GaN multiple channel heterostructures is presented. Doping is utilized in conjunction with polarization effects to achieve high carrier mobility and high sheet carrier density in each channel, while maintaining a low energy barrier for majority carrier transfer between channels. Several eight-period Si-doped Al0.22Ga0.78N/GaN heterostructures were grown by metalorganic chemical vapor deposition, according to the methodology. Sheet electron densities around 7.7×1013 cm−2, and room temperature electron mobilities as high as 1200 cm2/V s were measured. Applications for the structure include lateral current spreading layers in III-nitride visible light and UV emitters and detectors, and high conductance source and drain access regions in AlGaN/GaN high electron mobility transistors.