Structure and manufacture of x-ray mask pellicle with washer-shaped member

Abstract

A precise thickness bulk etchable wafer material, that is responsive to protection with an oxide that inhibits insertion of an etch responsiveness altering material, is assembled with a membrane material that is susceptible to deposition processes. A bulk etch then removes most of the wafer. The arrangement permits the strength and rigidity of the bulk spacer to serve to permit the finely controllable deposition processes for ultra thin and wider ranges of membrane materials, the selective protection for spacer shaping and finally, the removal by the low stress process of etching, of the unused bulk spacer material. An oxide layer is patterned on a bulk spacer material wafer that has a thickness of the gap between an X-ray mask and the to be patterned oxide. The oxide on the bulk spacer material prevents conversion, through the exposed surface of the bulk spacer material wafer, of a portion of the wafer that is to serve as the spacer to a different etch responsiveness from that of the bulk spacer material. The exposed bulk spacer material wafer is converted to a depth that will serve as the spacer and to protect the edges. The oxide is then removed. The membrane is deposited over the full surface of the bulk spacer material. The bulk wafer is removed down to the converted portion using the imparted different etch responsivness.