XUV Mo/Si Multilayer Mirrors Deposited by RF Magnetron Sputtering,

MoSi multilayer mirrors with a high reflectance at 132 angstroms were deposited using rf magnetron sputtering. The reflectance as a function of the deposition conditions was studied by varying both the argon partial pressure and the target power. To provide uniform coatings, the samples were rotated about their axis during deposition. In addition, the substrates could also be oscillated back and forth over the target giving rise to multiple passes during the deposition of each layer. With specially designed masks placed between the substrate and the target, this oscillation provides a further improvement in the uniformity. Furthermore, the multiple passes help average out any fluctuations in the deposition rate. Uniformity measurements of samples, made with and without the oscillations, will be presented. The multilayer mirrors were characterized by x-ray diffraction XRD, TEM and reflectance measurements using synchrotron radiation. A new cleaving technique was used to prepare the samples for the TEM studies. In addition to being quick, this method introduces less sample damage than the standard ion milling technique.