Comprising an ultra-thin layer of crystalline 3C polytype silicon carbide (SiC) in a silicon frame, and available in a wide range of window sizes and membrane thicknesses. These membranes have superior transmission characteristics in the 10 to 20nm wavelength range, and superior transmission in the 1 to 3 nm range, compared to traditional silicon nitride windows. Simulated transmission data is shown below (LBNL CXRO X-Ray database). SiC has a thermal conductivity four times that of the silicon nitride typically used as a membrane material. These membranes are therefore advantageous for applications where uniform heating of the membrane area is required. SiC is a wide band gap semiconductor, and is therefore electrically conductive at room temperature, with resistivity in the range 10-1000 Ωcm.
Silson can supply two grades of SiC membrane with different levels of surface roughness, as shown in the atomic force microscope images below, taken from the centre of a 100nm thick SiC membrane.
Available in a 381μm thick frame, with frame sizes of 5mm, 7.5mm and 10mm (other sizes available on request), and with SiC membrane thicknesses from 30nm up to 200nm. Thin film coatings can be supplied on request (Zr, Fe, Ni, SiO2, Al, Au, Cr, Ti, please inquire for our full range of materials).
UV, visible and IR transmittance of a 200nm SiC membrane
Silson recommends the CXRO database for calculations of the transmission of their thin membranes. You can find this page here.