Determination of multilayer thicknesses of GaAs/AlAs superlattice by grazing incidence X-ray reflectivity

Abstract

The grazing incidence X-ray reflectivity is used to determine the multilayer thickness of GaAs/AlAs supperlattice. The measurement process includes the fitting model and the measurement conditions (different powers of 45 kV × 40 mA, 40 kV × 40 mA and 35 kV × 40 mA, different step sizes of 0.005°, 0.008° and 0.010°, and different times per step of 1 s, 2 s, 3 s). In order to obtain the valid measurement process, the combined standard deviation is used as the normal of the fitting results selection. As a result, the measurement condition of 0.008° step size and 2 s time per step with the power 40 kV × 40 mA is selectable with the operation stability of facilities and smaller error.