Measurement of minute local strain in semiconductor materials and electronic devices by using a highly parallel X-ray microbeam

We have developed an X-ray microbeam with a small angular divergence by adopting X-ray optics with successive use of asymmetric Bragg reflection from silicon crystals for the both polarizations of the synchrotron X-rays. The microbeam actually obtained is several microns in size and possesses an angular divergence of less than 2 arcsec which enables us to measure the strain of 10 −5–10 −6. By scanning the sample against the microbeam, distribution of the minute local strain in various regions of semiconductor crystals for electronic devices, e.g., the strain around the SiO 2/Si film edge in silicon devices, the strain in an InGaAsP/InP stripe laser were measured.