Dislocation scattering effect on two-dimensional electron gas transport in GaN/AlGaN modulation-doped heterostructures

We present the effect of all standard scattering mechanisms, including scattering by acoustic and optical phonons, remote and background impurities and dislocation, on two-dimensional electron gas (2DEG) transport in AlGaN/GaN modulation doped-heterostructures. The most important scattering mechanisms limiting electron transport are identified. From the calculated dependence of mobility on temperature, it is clear that dislocation scattering dominates the low-temperature mobility of two-dimensional electrons in GaN/AlGaN structures with a high electron density View the MathML source and the maximum 2DEG mobilities will be in the 102–View the MathML source range for dislocation density of View the MathML source and carrier densities in the 1×1012–View the MathML source. This theoretical calculations fairly agree with the same mobility value obtained by the experimental for View the MathML source dislocation density. The results are compared to the transport to quantum lifetime ratios due to charge dislocations. We find that the ratio is larger for dislocation scattering than for impurity scattering.