STRESS STABILIZATION OF TANTALUM ABSORBERS ON X-RAY MASKS

We developed a new technique for stabilizing the stress in Ta sputter deposited over epitaxially grown SiC. The technique is to modify the S iC surface before deposition by bombardment with Ar ions. The stress i n the Ta deposited over the SiC treated in Ar plasma was much more sta ble than that of Ta deposited on as - prepared SiC, and its change due to heating for 6.5 hours at 200-degrees-C in air was less than 1.5 x 10(8) dyn/cm3. Structure analysis of Ta using X-ray diffraction reveal ed that the more stable Ta has a beta -phase structure with strong (00 2) orientation.