Two-dimensional electron gas in GaN–AlGaN heterostructures deposited using trimethylamine-alane as the aluminum source in low pressure metalorganic chemical vapor deposition

In this letter, we report the fabrication of high quality GaN–Al0.1Ga0.9N heterostructures using trimethylamine-alane as the aluminum source. The two-dimensional electron gas (2DEG) with mobility values as high as 5000 cm2/V s at 150 K is demonstrated. We also present the results of our calculations of the 2DEG mobility at the GaN–Al0.1Ga0.9N heterointerface. Our calculations show that the mobility enhancement in the 2DEG is related to a much larger volume carrier concentration (compared to bulk GaN) and, therefore, to a larger Fermi energy and to a more effective screening of impurity and piezoelectric scattering.