For more than 50 years, X-ray topography (XRT) has been an indispensable industrial and research tool for crystal growth of functional materials, since crystalline defects, such as dislocations, stacking faults, etc., can be detected with this technique non-destructively. Industrial demand for almost dislocation-free Si has greatly contributed to this technique, providing important insights for the improvement of crystal quality. These days, various functional bulk single crystals other than Si have been grown and industrial application of these crystals have been explored. X-ray topography is also employed to investigate growth conditions and correlations between physical properties and crystalline qualities of these crystals.
Even for Si wafers that are originally dislocationfree, there is a possibility that strains and/or defects will be introduced during steps in device fabrication processes; thus, there arises a need for non-destructive characterization without changing the device structure fabricated on the Si wafers. X-ray topography is, therefore, used not only for characterization of slices of ingots or bare wafers, but also for the inspection of processed wafers.
In this article, important features and functions equipped in Rigaku’s latest X-ray topograph apparatus, XRTmicron™ are reviewed briefly and application data from this apparatus related to modern functional crystals will be introduced.