Ta Film Properties for X-Ray Mask Absorbers

Abstract
The properties of absorber materials for X-ray masks which can be patterned by a subtractive process are investigated. Highly pure film can be deposited using Xe rather than Ar as a working gas of RF sputtering. The stress of the Ta film can be controlled more precisely than either Re or W. Ta film deposited by RF sputtering is highly oriented, and has a high purity and a high density. Furthermore, its stress does not change even after annealing at 400°C.