Nondestructive characterization of pseudomorphic high‐electron‐mobility transistor structures using x‐ray diffraction and reflectivity

X‐ray diffraction and glancing angle‐of‐incidence x‐ray reflectivity are applied to the analysis of AlGaAs–InGaAs–GaAs pseudomorphic high‐electron‐mobility transistor structures. Through comparisons between simulations and measured data, we are able to determine the InAs mole fraction and thickness of the InGaAs channel with precisions of ±0.003 and ±3 A, respectively. The period of the AlGaAs/GaAs superlattice buffer, and the combined thickness of the AlGaAs gate and GaAs contact layers are determined with a precision of ±2%. Thickness values determined with these x‐ray techniques agree with those determined by transmission electron microscopy to within 6%.