X-ray fluorescence apparatus for contamination monitoring

An apparatus for X-ray measurement, comprising:

• an X-ray source, which is configured to generate and direct an X-ray beam to a surface of a sample;
• an X-ray detector, configured to detect X-ray fluorescence radiation emitted from the sample in response to being excited by the X-ray beam;
• and
• a multi-layer shield, which comprises multiple layers, each layer configured to attenuate stray X-ray fluorescence radiation of progressively-increasing wavelength emitted toward the X-ray detector from a previous layer of the multi-layer shield.

A method for X-ray measurement, the method comprising:

• generating and directing an X-ray beam to be incident at a grazing angle on a surface of a sample;
• measuring X-ray fluorescence emitted from the surface of the sample in response to being excited by the X-ray beam;
• measuring an inclination of the surface of the sample;
• and
• based on the measured inclination, calibrating the grazing angle, and, based on the measured X-ray fluorescence, further fine-tuning the grazing angle.

A method for X-ray measurement, the method comprising:

• generating and directing an X-ray beam to a surface of a sample;
• measuring X-ray fluorescence radiation emitted from the sample in response to being excited by the X-ray beam;
• and
• attenuating stray X-ray fluorescence radiation of progressively-increasing wavelengths emitted from a previous layer using a multi-layer shield comprising multiple layers.