High numerical aperture ring field projection system for extreme ultraviolet lithography

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873554

Hudyma, Russell ^[1]; Shafer, David R ^[2]

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1. 218 Eastridge Dr., San Ramon, CA 94583-4905
2. 56 Drake La., Fairfield, CT 06430-2925

An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 9.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 .mu.m.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Hudyma, Russell (218 Eastridge Dr., San Ramon, CA 94583-4905);Shafer, David R. (56 Drake La., Fairfield, CT 06430-2925)
• Patent Number(s): US 6188513
• OSTI ID: 873554
• Country of Publication: United States
• Language: English

Related Subjects

numerical
aperture
field
projection
extreme
ultraviolet
lithography
all-reflective
optical
photolithography
camera
source
euv
radiation
wafer
mask
imaged
convex
mirror
third
fourth
concave
fifth
sixth
configured
five
six
mirrors
receive
chief
ray
incidence
angle
substantially
degree
receives
14
reflecting
surfaces
aspheric
departure
12
16
mirrors receives
all-reflective optical
reflective optical
numerical aperture
reflecting surfaces
aspheric departure
ultraviolet lithography
extreme ultraviolet
reflecting surface
concave mirror
six mirrors
chief ray
convex mirror
euv radiation
six reflecting
incidence angle
sixth concave
third convex
fifth convex
field projection
fourth concave
projection photolithography
photolithography camera
mirrors receive
lithography camera
/359/