METHOD FOR THE PREPARATION OF A MASK FOR X-RAY LITHOGRAPHY

摘要

A method of obtaining a mask for X-ray lithography having a thin oxidized metal membrane supported on an annular silicon base. The method consists of the following steps: (a) deposition of a metal layer on a silicon wafer; (b) oxidation of the metal layer to form a continuous thin oxide layer; (c) etching selectively a portion of the backside of said substrate, obtaining a thin membrane of oxidized metal at the etched portion; and (d) obtaining a pattern delineation through a photoresist on said membrane framed by the silicon substrate. A most preferred deposited metal is aluminum which is converted to aluminum oxide. Then a portion of the silicon substrate is removed in order to expose the aluminum oxide membrane attached to the remaining silicon substrate. The mask prepared according to the present invention does not suffer from any distortion and preserves its accuracy even under the stresses incurred during the mask preparation and use.