Extreme-UV lithography system
- Livermore, CA
- Albuquerque, NM
A photolithography system that employs a condenser that includes a series of aspheric mirrors on one side of a small, incoherent source of radiation producing a series of beams is provided. Each aspheric mirror images the quasi point source into a curved line segment. A relatively small arc of the ring image is needed by the camera; all of the beams are so manipulated that they all fall onto this same arc needed by the camera. Also, all of the beams are aimed through the camera's virtual entrance pupil. The condenser includes a correcting mirror for reshaping a beam segment which improves the overall system efficiency. The condenser efficiently fills the larger radius ringfield created by today's advanced camera designs. The system further includes (i) means for adjusting the intensity profile at the camera's entrance pupil or (ii) means for partially shielding the illumination imaging onto the mask or wafer. The adjusting means can, for example, change at least one of: (i) partial coherence of the photolithography system, (ii) mask image illumination uniformity on the wafer or (iii) centroid position of the illumination flux in the entrance pupil. A particularly preferred adjusting means includes at least one vignetting mask that covers at least a portion of the at least two substantially equal radial segments of the parent aspheric mirror.
- Research Organization:
- SANDIA CORP
- DOE Contract Number:
- AC04-94AL85000
- Assignee:
- EUV LLC (Livermore, CA)
- Patent Number(s):
- US 6225027
- OSTI ID:
- 873699
- Country of Publication:
- United States
- Language:
- English
EUV optical design for a 100-nm CD imaging system
|
conference | June 1998 |
Similar Records
Reticle stage based linear dosimeter
Extreme-UV lithography condenser
Related Subjects
adjusting
advanced
aimed
aspheric
aspheric mirror
aspheric mirrors
beam
beam segment
beams
camera
centroid
change
coherence
coherent source
condenser
correcting
correcting mirror
covers
created
curved
designs
efficiency
efficiently
employs
entrance
entrance pupil
equal
example
extreme-uv
extreme-uv lithography
fall
field created
fills
flux
ii
iii
illumination
image
images
imaging
improves
incoherent
incoherent source
intensity
intensity profile
larger
line
lithography
manipulated
mask
mask image
means
mirror
mirror image
mirror images
mirrors
overall
parent
parent aspheric
partial
partially
particularly
particularly preferred
photolithography
portion
position
preferred
producing
profile
provided
pupil
quasi
radial
radiation
radius
relatively
reshaping
ringfield
segment
segments
series
shielding
source
substantially
substantially equal
uniformity
vignetting
virtual
wafer