Double crystal x-ray rocking curves of multiple layer structures

Interference effects in double crystal x-ray rocking curves arising from the existence of a sub-micrometre layer sandwiched between two layers of different composition are studied by simulation and experiment. For GaInAs structures on InP with a quarter micrometre middle layer, composition and thickness could be determined to an accuracy of 50 ppm and 50 AA respectively. There is an excellent consistency between interference structures and layer parameters deduced from various reflections. The sensitivity of the interference structures to other layer parameter variations is investigated.