IP Library › Granted Patent US 7,522,265
Granted Patent B2
US 7,522,265 · App. 11/478,692 · Granted Apr 21, 2009

Optical aligner using a compensation light

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Quick Facts
Patent No.
US 7,522,265
App. No.
11/478,692
Granted
Apr 21, 2009
Kind
B2
Abstract

An optical aligner includes a light source for generating an exposure light, an irradiation optical system for irradiating the exposure light onto a reticle, a projection optical system for transmitting the exposure light passed by the reticle to project the image of the reticle onto a photoresist mask, and a compensation optical system for generating a compensation light incident onto the reticle. The reticle reflects the compensation light in the light-shield area of the reticle to be incident onto the photoresist film. The compensation light compensates a flare light generated by the reticle from the exposure light to form a uniform pattern on the wafer.

Claims (13)

1. An optical aligner comprising: a light source for generating an exposure light; an irradiation optical system for irradiating said exposure light onto a mask having a light-shield area and a transparent area; a projection optical system for transmitting said exposure light passed by said mask toward a photoreceptor to thereby project an image of said mask onto said photoreceptor; and a compensation optical system for transmitting a compensation light onto said photoreceptor, wherein said compensation light has a first optical intensity distribution different from a second optical intensity distribution of a flare light generated from said exposure light.

2. The optical aligner according to claim 1 , wherein said compensation light is reflected by said light-shield area of said mask to be incident onto said photoreceptor.

3. The optical aligner according to claim 2 , wherein said compensation light is guided by said projection optical system.

4. The optical aligner according to claim 2 , wherein said compensation optical system includes a compensation projection optical system for transmitting said compensation light from said mask to said photoreceptor.

5. The optical aligner according to claim 2 , wherein said compensation light is reflected by a mirror toward said mask.

6. The optical aligner according to claim 1 , wherein said photoreceptor is a positive or negative photoresist film formed on a wafer.

7. The optical aligner according to claim 1 , wherein said first optical intensity distribution is substantially opposite to said second optical intensity distribution.

8. A method comprising the steps of:

irradiating an exposure light onto a mask having a light-shield area and a transparent area, to project an image of said mask onto a photoreceptor; and

irradiating a compensation light onto said photoreceptor, wherein said compensation light has a first optical intensity distribution different from a second optical intensity distribution of a flare light generated from said exposure light.

9. The method according to claim 8 , wherein said compensation light is reflected by said light-shield area of said mask to be incident onto said photoreceptor.

10. The method according to claim 9 , wherein said photoreceptor is a photoresist film formed on a wafer.

11. The method according to claim 9 , wherein said first optical intensity distribution is substantially opposite to said second optical intensity distribution.