Euv actinic reticle inspection system using imaging sensor with thin film spectral purity filter coating
AssigneeKLA-Tencor Corporation
InventorDaimian Wang
Life of this patent
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Abstract
An extreme ultraviolet (EUV) actinic reticle imaging system suitable for discharge produced plasma (DPP) or laser produced plasma (LPP) reticle imaging systems using a thin film coating spectral purity filter (SPF) positioned on or proximate to the EUV imaging sensor; an EUV imaging sensor carrying this SPF; and methods for making and using the SPF for reticle inspection. The coating may be applied to the imaging sensor in any manner suitable for the particular coating selected. The coating may be composed of a single layer or multiple layers. Typical SPF coating materials include zirconium (Zr) and silicon-zirconium (Si/Zr) in a thickness between 10 nm and 100 nm.
Claims25
An extreme ultra violet reticle inspection apparatus, comprising:
- an extreme ultra violet imaging sensor;
- and
- a thin film coating spectral purity filter disposed on or located proximate to the imaging sensor having one or more selected spectral characteristics.
An extreme ultra violet reticle inspection system comprising:
- an extreme ultraviolet light source;
- a reticle illumination position for receiving a reticle for inspection;
- an extreme ultraviolet imaging sensor;
- a set of illumination optics located between the extreme ultraviolet light source and the reticle illumination position;
- a set of objective optics located between the reticle illumination position and the imaging sensor;
- and
- a thin film coating spectral purity filter disposed on or located proximate to the imaging sensor having one or more selected spectral characteristics.
A method for inspecting an extreme ultra violet reticle, comprising:
- generating extreme ultraviolet light utilizing an extreme ultraviolet light source;
- directing the extreme ultraviolet light from the extreme ultraviolet light source to a reticle via a set of illumination optics;
- directing extreme ultraviolet light reflected from the reticle toward an extreme ultraviolet imaging sensor via a set of objective optics;
- filtering a portion of the extreme ultraviolet light reflected from the reticle utilizing a thin film coating disposed on or positioned proximate to the imaging sensor, the thin film coating having one or more selected spectral characteristics;
- and
- receiving a portion of the light filtered by the thin film coating utilizing the imaging sensor.
Dependencies are inferred from the claim text.