Patent ID: 6428937
Filing Date: 2002-08-06
Classification: G03F

Abstract:
A method for manufacturing a reticle blank for use in making a reticle for charged-particle-beam microlithography, the method comprising the steps:preparing an SOI substrate comprising a silicon support substrate, an etch-stop layer formed on a first major surface of the silicon support substrate, and a membrane-forming layer formed on the etch-stop layer; forming a dry-etching mask on a second major surface of the silicon support substrate, the dry-etching mask comprising a silicon oxide layer formed on the second major surface and a resist layer applied to the silicon oxide layer, the dry-etching mask defining a pattern of windows located at positions corresponding to spaces to be located between struts of the reticle blank; according to the pattern of windows in the dry-etching mask, dry-etching the silicon support substrate; and removing exposed portions of the etch-stop layer and remaining portions of the dry-etch mask to form the reticle blank including a membrane formed by the membrane-forming layer.