HR XRD FOR THE ANALYSIS OF ULTRATHIN CENTROSYMMETRIC STRAINED DB-RTD HETEROSTRUCTURES

A nondestructive analysis of strained centrosymmetric double-barrier r esonant tunnelling diode (DB-RTD) layers is proposed. In the measured (004) rocking curves, the intrinsic barrier-well-barrier sequence resu lts in a beat under the strained layer peak which can be used for laye r analysis down to a thickness of nine monolayers. Based on the kinema tical theory, analytical relations are deduced which allow a direct co rrelation of the measured rocking-curve data to barrier and well-layer data. This method is applied to InP-based DB-RTD and is proven to be applicable to final devices including thick but lattice-matched contac t layers. (C) 1998 Published by Elsevier Science S.A.