XRF measurement apparatus for detecting contaminations on the bevel of a wafer
AssigneeBruker AXS GmbH
InventorAssunta Vigliante
Life of this patent
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Abstract
An XRF (XRF=x-ray fluorescence) measurement apparatus (1) has an x-ray source (2) for generating x-rays (4), x-ray optics (3) for directing x-rays (4) from the x-ray source (2) to a sample (5) and an EDS (EDS=energy dispersive spectroscopy) detector (7) for detecting fluorescent x-rays (14) from the sample (5). The apparatus is characterized in that the sample (5) is a wafer (6), in particular a Si wafer, wherein the x-ray optics (3) is positioned to direct the x-rays (4) onto the bevel (12) of the wafer (6). The x-ray source (2) plus the x-ray optics (3) has a brilliance of at least 5*107 counts/sec mm2, preferably at least 1*108counts/sec mm2. The apparatus allows an improved contamination control of wafers, in particular silicon wafers.
Claims15
An XRF (XRF=x-ray fluorescence) measurement apparatus comprising:
- a sample, wherein said sample is a wafer or an Si wafer having a bevel;
- an x-ray source for generating x-rays;
- x-ray optics elements, said x-ray optics elements being disposed, structured and dimensioned to direct x-rays from the x-ray source onto said bevel of said wafer, wherein a combination of said x-ray source and said x-ray optics elements drive generated x-rays to a brilliance of at least 5*107 counts/sec mm2;
- an EDS (EDS=energy dispersive spectroscopy) detector for detecting fluorescent x-rays from said wafer;
- auxiliary x-ray optics elements for directing x-rays from said x-ray source onto said wafer;
- and
- a switching element for switching the apparatus between a first operation mode and a second operation mode, wherein, in said first operation mode, said x-ray optics elements are positioned to direct x-rays from said x-ray source onto said bevel of said wafer and, in said second operation mode, said auxiliary x-ray optics elements are positioned to direct x-rays from said x-ray source onto a flat side of said wafer, wherein said switching element comprises a first moving stage for exchanging said x-ray optics elements with said auxiliary x-ray optics elements by displacing said x-ray optics elements and said auxiliary x-ray optics elements substantially transverse to a direction of travel of the x-rays, said switching element also comprising a second moving stage for pivoting and shifting said wafer relative to a path of the x-rays when switching from said first to said second operation mode.
Dependencies are inferred from the claim text.