A Comprehensive Analysis of the 2-DEG Transport Properties in InxAl1 – xN/AlN/GaN Heterostructure: Experiments and Numerical Simulations

A comprehensive investigation on the low-field 2-DEG mobility in In
_x
Al
$_{{1}-{x}}\text{N}$
/AlN/GaN heterostructure has been made through Hall experimental and numerical calculation based on an ensemble Monte Carlo (MC) approach. Hall measurement on a lattice-matched (LM) In
_0.18
Al
_0.82
N/AlN/GaN heterostructure grown by metal-organic chemical vapor deposition (MOCVD) has been carried out as a function of temperature ranging from 77 to 405 K. A more rigorous model is presented taking both inter- and intra-subband scattering into account. The scattering rates are derived from the results of the electron density, the quantized energy levels, and the corresponding wave functions based on the self-consistent solutions of Poisson’s and Schrödinger’s equation given in our previous work. We confirm that the interface scattering process dominates the mobility within the low temperature (77–130 K), as increasing of the temperature, the highly inelastic scattering caused by partial occupation of the higher subband is responsible for the rapid degradation of the 2-DEG mobility. The role of surface morphology and indium fraction of the heterostructure on the dependence of the 2-DEG mobility have been clarified qualitatively in detail. The calculated results are widely compared with the published literature and our experimental finding. A reasonable agreement is achieved.