Maskless, reticle-free, lithography

Patent · Tue Nov 25 04:00:00 EST 1997

OSTI ID:871251

Ceglio, Natale M ^[1]; Markle, David A ^[2]

---

1. Livermore, CA
2. Saratoga, CA

A lithography system in which the mask or reticle, which usually carries the pattern to be printed onto a substrate, is replaced by a programmable array of binary (i.e. on/off) light valves or switches which can be programmed to replicate a portion of the pattern each time an illuminating light source is flashed. The pattern of light produced by the programmable array is imaged onto a lithographic substrate which is mounted on a scanning stage as is common in optical lithography. The stage motion and the pattern of light displayed by the programmable array are precisely synchronized with the flashing illumination system so that each flash accurately positions the image of the pattern on the substrate. This is achieved by advancing the pattern held in the programmable array by an amount which corresponds to the travel of the substrate stage each time the light source flashes. In this manner the image is built up of multiple flashes and an isolated defect in the array will only have a small effect on the printed pattern. The method includes projection lithographies using radiation other than optical or ultraviolet light. The programmable array of binary switches would be used to control extreme ultraviolet (EUV), x-ray, or electron, illumination systems, obviating the need for stable, defect free masks for projection EUV, x-ray, or electron, lithographies.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA); Ultratech Stepper, Inc. (San Jose, CA)
• Patent Number(s): US 5691541
• Application Number: 08/645531
• OSTI ID: 871251
• Country of Publication: United States
• Language: English

Related Subjects

/250/355/378/
accurately
accurately position
accurately positions
achieved
advancing
amount
array
binary
built
carries
common
control
corresponds
defect
defect free
displayed
effect
electron
euv
extreme
extreme ultraviolet
flash
flashed
flashes
flashing
free
held
illuminating
illuminating light
illumination
illumination systems
image
imaged
isolated
light
light produced
light source
light valve
light valves
lithographic
lithographies
lithography
manner
mask
maskless
masks
method
motion
mounted
multiple
obviating
optical
pattern
portion
positions
precisely
printed
produced
programmable
programmable array
programmed
projection
radiation
replaced
replicate
reticle
reticle-free
scanning
source
stable
stage
substrate
switches
synchronized
systems
time
travel
ultraviolet
ultraviolet light
valves
violet light
x-ray