Leaky absorber for extreme ultraviolet mask
OwnerPei-Yang Yaninventor
Life of this patent
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Abstract
The present invention discloses a method of forming a mask including: providing a substrate; forming a multilayer mirror for EUV light over the substrate; forming a leaky absorber for the EUV light over the multilayer mirror; and patterning the leaky absorber into a first region that is strongly reflective and a second region that is weakly reflective. The present invention further discloses an EUV mask including: a substrate; a multilayer mirror located over the substrate, the multilayer mirror having a first region and a second region; and a leaky absorber located over the second region of the multiplayer mirror, the leaky absorber shifting phase of incident light by 180 degrees.
Claims18
A method of forming a mask comprising:
- providing a substrate;
- forming a multilayer mirror for EUV light over said substrate;
- forming a leaky absorber for said EUV light over said multilayer mirror;
- and
- patterning said leaky absorber into a first region that is strongly reflective and a second region that is weakly reflective.
A method of forming an EUV mask comprising:
- providing a substrate;
- forming a mirror over said substrate, said mirror comprising:
- alternating layers of a reflective material and a transmissive material;
- forming a leaky absorber over said mirror, said leaky absorber shifting phase of incident light by 180 degrees;
- and
- removing said leaky absorber in a first region to uncover said mirror.
An EUV mask comprising:
- a substrate;
- a multilayer mirror disposed over said substrate, said multilayer mirror having a first region and a second region;
- and
- a leaky absorber disposed over said second region of said multiplayer mirror, said leaky absorber shifting phase of incident light by 180 degrees.
A reflective mask for oblique incident light comprising:
- a substrate;
- a multilayer mirror disposed over said substrate, said multilayer mirror having a first region and a second region;
- and
- an absorber disposed over said second region of said multilayer mirror wherein said absorber permits said multilayer mirror to reflect about 1.0-3.0% of said oblique incident light with a phase shift of 180 degrees.
Dependencies are inferred from the claim text.