US 5,958,629 A · Using thin films as etch stop in EUV mask fabrication process

Abstract

A silicon-substrate based reflective photolithographic mask fabrication technique is described. The process begins with a multilayer, resonant reflecting substrate. A thin layer of silicon dioxide or other material capable of acting as an etch stop layer is deposited thereon. Then, a transmissive layer is deposited on the thin layer of etch stop layer. The transmissive layer is substantially transmissive to the wavelength of light used in the photolithography as well as capable of being selectively etched relative to the underlying etch stop layer. Then, the transmissive layer is etched to open preselected, absorptive areas. An absorptive layer is then deposited thereon. The absorptive layer is substantially absorptive to the wavelength of light used as well as capable of completely filling the opened areas of the transmissive layer. The absorptive layer is then planarized, and a thin protective cap is deposited thereon.

Claims18

Dependent claims

A method of fabricating a photolithographic mask, comprising:

forming a substantially transmissive etch stop layer on a mask substrate;
forming an etchable material on the etch stop layer;
and
etching a trench into the etchable material.

1 more element

Dependencies are inferred from the claim text.

Using thin films as etch stop in EUV mask fabrication process

Life of this patent

Using thin films as etch stop in EUV mask fabrication process

Life of this patent

Abstract

Claims18