Measurement accuracy analysis for crystal plane spacing of nitride epitaxial layer by x-ray diffraction

In order to realize high accuracy measurement of the physical dimension of unit cells in a crystal lattice, the measurement accuracy analysis for crystal plane spacing of nitride epitaxial layer is discussed. An angular analysis for X-ray diffractometer system is established and the measurement uncertainty from the experimental apparatus, measurement method are also analyzed. Experimental results indicate that the accuracy of the system’s angular can get U = ±0.01° (k=2) and the measuring accuracy of lattice plane spacing is within 0.01% of the d-spacing. These results represent an improvement in the existing measurement capabilities by more than an order of magnitude and make more numerous systematic effects visible and reproducible.