Characteristics of Ta-based amorphous alloy film for x-ray mask absorbers

We examined Ta-based amorphous alloy films and studied their characteristics for application in an x-ray mask with dimensions of the 0.1 mu m design rule. From the viewpoint of x-ray absorption, Ge is a suitable element for a compound with Ta. We found that a Ge inclusion atomic ratio of 20%-30% in a Ta-Ge compound film was suitable with respect to stress control and stress stability. It was possible to adjust the stress of the Ta-Ge film after deposition by annealing it at high temperature while maintaining control as good as 0.56 MPa/degrees C. During pattern fabrication by dry etching, it was possible to successfully etch the Ta-Ge film with a single-layer resist using a chroline based plasma, and scale patterns of 0.1 mu m were obtained. (C) 1998 American Vacuum Society. [S0734-211X(98)16906-8].