Resistless electron beam lithography technique for the fabrication of x-ray masks

Among the key issues for the use of X-ray lithography as a next generation lithography process is the fabrication of masks with high resolution and high aspect ratio absorbent structures. Due to its chemical stability, tantalum is the most widely used absorber for this application. However, the chemical resistance of the etch mask used to pattern the tantalum layer is a problem that needs to be addressed. In this paper, we present a fabrication technique which eliminates the use of such an intermediary etch mask by using a high resolution Silicide Direct-Write Electron Beam Lithography process to pattern the masks.