Differential-mode grazing-incidence diffraction from nanometre-layer heterostructures

Abstract
The differential mode of the grazing-incidence diffraction is employed for the characterization of a thin Ga1-xAlxAs/GaAs (001) heterostructure. Using a high resolution detector system a conventional X-ray source is appropriate to record the fine structure of the diffraction curve. The quality of experimental curves permits the authors to detect the thickness of both the nondiffracting top part and the perfect crystalline portion of the layer. Their quantitative determination results from simulation of the curve by means of the dynamical and the kinematic theory. Both yield nearly the same crystalline thickness; however, they differ somewhat for the top part. A quantitative interpretation of the real structure of sample is impossible due to the limited experimental resolution.