Beam blockers are gold cylinders placed on top of SiNx membranes, supported by a Si frame. They are used in X-ray optics, in order to block the zero order diffraction when using Fresnel zone plates for focusing, or blocking the central un-focused beam in capillary focusing devices.
Cylinder heights are in the 25 micrometer to 250 micrometer range, with
heights from few to 120 micrometer.
A gold frame surrounds the cylinder area, outside the membrane region. The gold frame has the same height as the cylinder and its role is to protect the cylinder and membrane in case the chip touches any flat surface with the gold structure side. This allows also safe storage, manipulation, and transportation.
The Si chips can be 5 mm x 5 mm or 3 mm x 3 mm. Other shapes and sizes also available on custom orders.
Membrane sizes are 0.5 mm x 0.5 mm or 1 mm x 1 mm and have a typical thickness of 0.35 um or 0.50 um. A Cr/Au layer used as plating base is also present. This leaves the membrane only slightly transparent in visible light. The plating base can be removed on demand, leaving the membrane highly transparent.