THERMAL-STABILITY OF SPUTTERED MO X AND W/X (X=BN-O, B4C-O, SI, AND C) MULTILAYER SOFT-X-RAY MIRRORS/

We prepared eight samples of Mo/X and W/X (X = BN:O, B4C:O, Si, and C) multilayers by magnetron sputtering. Analyses of x-ray photoelectron spectroscopy for the boron nitride and the B4C layers showed the conce ntration of 0 to be nonnegligible. We have evaluated the thermal stabi lity by measuring soft-x-ray specular reflectances before and after th ermal annealing occurs at temperatures as high as 700-degrees-C. The r esults suggest that the thermal stability depends largely on the inclu sion of low-density materials and not on the type of metal. Of the fou r low-density materials studied, BN:O is thermally the most stable, an d the Mo/BN:O multilayer, the most stable among the eight samples, sho ws stability as high as 700-degrees-C.