Abstract
We have demonstrated to form an x-ray microbeam with a narrow angular divergence in both vertical and horizontal polarization directions of synchrotron radiation x-rays by the use of successive asymmetric Bragg reflections. Using the highly parallel x-ray microbeam thus obtained, we are able to analyze the local minute strain of less than 10^<-5> in semiconductor materials and devices. A series of x-ray rocking curves have been obtained by scanning the sample against the x-ray microbeam. Variations of the reflection peak intensity, angular shift value and/or half widths inform us how strain is distributed in the materials with high spatial resolution. In addition, reciprocal space maps have been drawn with an analyzer crystal put behind the sample on the x-ray path. From those data, strain distribution can be analyzed in terms of both lattice tilt variation and lattice parameter variation independently. Strain near Si-oxide film edges on Si substrate or that in silicon-on-insulator (SOI) crystals or other semiconducting materials has been measured. The results of reciprocal space maps have shown that the strain in the bonded SOI layers is mainly due to the lattice tilt variation rather than the lattice parameter variation.
