US 8,076,055 B2 · Passivation of multi-layer mirror for extreme ultraviolet lithography

Abstract

A reflector structure suitable for extreme ultraviolet lithography (EUVL) is provided. The structure comprises a substrate having a multi-layer reflector. A capping layer is formed over the multi-layer reflector to prevent oxidation. In an embodiment, the capping layer is formed of an inert oxide, such as Al2O3, HfO2, ZrO2, Ta2O5, Y2O3-stabilized ZrO2, or the like. The capping layer may be formed by reactive sputtering in an oxygen environment, by non-reactive sputtering wherein the materials are sputtered directly from the respective oxide targets, by non-reactive sputtering of the metallic layer followed by full or partial oxidation (e.g., by natural oxidation, by oxidation in oxygen-containing plasmas, by oxidation in ozone (O3), or the like), by atomic level deposition (e.g., ALCVD), or the like.

Claims9

Dependent claims

A method of patterning a semiconductor device, the method comprising:

forming a photoresist material over a semiconductor wafer;
imaging a light source using a lithographic mirror of a reflective lithographic system to expose the photoresist material through a mask, the lithographic mirror comprising:
a first substrate formed of a low-thermal expansion material (LTEM);
a first multi-layer reflector of alternating layers of molybdenum and silicon formed on the first substrate;
and
a first capping layer formed in direct contact onto the first multi-layer reflector, the first capping layer comprising a single layer of an oxide that is chemically inert in an oxidizing environment, said layer of oxide selected from the group consisting of HfO2, Y2O3-stabilized ZrO2, and combinations thereof;
removing a portion of the photoresist material corresponding to the portion that was exposed or a portion that was not exposed;
and
modifying the semiconductor wafer where the photoresist material was removed.

6 more elements

Dependencies are inferred from the claim text.

Passivation of multi-layer mirror for extreme ultraviolet lithography

Life of this patent

Passivation of multi-layer mirror for extreme ultraviolet lithography

Life of this patent

Abstract

Claims9