Development of micro X-ray fluorescence spectrometer with multi excitation sources

X-ray fluorescence analysis (XRF) is a suitable technique for elemental analysis in nondestructive measurement. Recently, small area analysis by using the XRF technique has gained popularity. The synchrotron radiation source is responsible for the increase in the popularity of micro-XRF analysis. However, most people find it difficult to gain access to the synchrotron radiation facility. In this study, a micro-XRF system is developed for use in laboratories. To enable the use of this system, it is necessary to satisfy the following two conditions: (1) the excitation source must be optional for efficient excitation of the sample and (2) the X-rays must be focused. An X-ray tube with multi excitation sources has also been developed. In this tube, there are three targets, namely Cr, W, and Pd, on the anode, and each target can be excited sequentially. A doubly curved crystal (DCC) developed using a Si(111) crystal is used as the optics for focusing the X-rays into a beam with a diameter of less than 100 μm. A system composed of the X-ray tube and DCC optics is used to perform the small particle analysis of a Si wafer. The lower limit of detection (LLD) of the sample particle is estimated as 1.6 μm in diameter.