On the lateral decomposition, growth mode and defect nucleation in the InxGa1-xAs channel of HEMT devices depending on the growth temperature, well thickness and mismatch

We have investigated by TEM InA1As/In_xGa_1-xAs/InP heterostructures grown by Molecular Beam Epitaxy. Our interest has been focused on the effects of the growth temperature (in the range T_g=470°C→530°C), well composition (x_In=53%→80%) and well thickness (t_w = 3nm→14nm) on the development of lateral InGaAs decomposition, stacking fault and dislocation distributions and three-dimensional growth modes, the latest being strain-induced or driven by the InGaAs decomposition. We have correlated 2DEG Hall mobility measurements with TEM results to explain the degradation and anisotropy of the 2DEG mobilities.