Fabrication of tungsten-carbon multilayers for soft X-ray optics using excimer-laser-induced chemical vapor deposition technique

The authors describe a new excimer-laser-induced chemical vapor deposition (LCVD) technique using laser-beam-scanning and ultrahigh-vacuum chamber systems. Film thickness distribution is controlled by scanning the laser beam on the substrate. Film thicknesses in LCVD with film depositions on the laser-beam transmitting window are also controlled by changing the deposition time. Tungsten-carbon multilayers of uniform thickness are successfully deposited on 2-inch-diameter substrates without being restricted by the beam size. A soft X-ray reflectivity of 25% is obtained at a grazing angle of 6°, and reflection peaks up to the third order are clearly observed for the first time in LCVD.