Appeal 2007-3372
Application 10/651,351
Appellant’s claimed invention is directed to a method for producing a
pattern on a photoresist disposed on a substrate using a mask and wherein a
mask pattern image is altered with a nonzero spherical aberration value.1
The altered mask pattern image is focused at approximately mid-depth of the
photoresist. Claims 1 and 11 are illustrative and reproduced below:
1. A method of producing a pattern on a photoresist,
comprising:
providing a mask having a pattern defined thereon;
disposing the mask between an illumination source and a substrate having a
photoresist disposed thereon;
irradiating the mask with light from the illumination source to produce a
mask pattern image;
altering the mask pattern image with nonzero spherical aberration value
selected to at least partially compensate for spherical aberration
induced by the photoresist; and
focusing the altered mask pattern image at approximately a mid-depth of the
photoresist on the substrate.
11. A method of producing a pattern on a photoresist,
comprising:
disposing a mask having a pattern defined thereon between an illumination
source and a substrate having a photoresist disposed thereon;
irradiating the mask with light from the illumination source to produce a
mask pattern image;
1 Appellant explains that “[s]pherical aberration is caused by using
spherically shaped lenses and mirrors because truly spherical surfaces do not
form sharp images” (Specification ¶ 0005). Appellant’s drawing Figure 2
illustrates a prior art Example of a spherical aberration.
2
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: September 9, 2013