US Patent 7519153 X-ray metrology with diffractors

An electron probe microanalysis (EPMA) system includes a graded multilayer diffractor for tightly focusing output x-rays onto an x-ray detector. The graded multilayer construction of the diffractor allows a high x-ray flux to be generated in a small measurement spot, which results in a high measurement throughput. The enhanced measurement efficiency provided by the graded multilayer diffractor can allow an EPMA system to be used as an in-line monitoring tool. The graded multilayer diffractor can include multiple reflecting surfaces. Multiple graded multilayer diffractors can also be used.