STRAIN DISTRIBUTION OF THE INTERFACE BETWEEN SUBSTRATE AND EPITAXIAL LAYER OF SILICON BY X-RAY DOUBLE CRYSTAL METHOD

X-ray diffraction from phosphorus-doped epitaxial silicon layers containing a strain gradient are studied through the double crystal method. Diffraction peaks between the two main peaks from the silicon substrate and epitaxially grown layer are related to the strain gradient at the substrate-layer interface. The relations between the periodicity and the intensity of the subpeaks and the thickness of the epitaxial layer depends on the strain distribution near the interface. The subpeaks are experimentally observed under the following conditions: phosphorus concentration in the epitaxial layer is 3-9 × 1019 atoms/cm 8, thickness of the layer is 3-9 μm, radius of the curvature of the specimen is >2 × 103 cm. The strain distribution gradient (Δd/d/t) near the interface must be smaller than 6 × 10-5/μm. © 1979, The Electrochemical Society, Inc. All rights reserved.