Abstract
Minute strain fields in a floating-Lone-grown (FZ) silicon crystal containing D defects have been measured by X-ray topography with highly collimated X-rays of less than 0·01 divergence. The region containing D defects (the D region) in an as-grown FZ silicon wafer has been observed for the first time. Contrast analysis of the topographs shows that the 220 lattice spacing decreased with increasing Δd/d between 9·7 × 10−7 and 9·2 × 10−6 in the D region. These minute strain fields are caused by vacancy-type microdefects in the D region.