Method and device for producing features on a photolithographic layer

• US 5,936,713 A
• Filed: 01/29/1998
• Issued: 08/10/1999
• Est. Priority Date: 06/23/1995
• Status: Expired due to Term

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Kuck, Heinz, Paufler, Jorg, Seltmann, Rolf
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): KIM, PETER B
• Application Number:
  US08/973,805
• Time in Patent Office: 558 Days
• Field of Search: 355/40, 355/67, 355/53, 355/71, 359/569, 430/394, 430/396, 353/33
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70466 Multiple exposures, e.g. combination of fine and coarse exposures, double patterning or multiple exposures for printing a single feature stitching G03F7/70475

Abstract

In a method for structuring a photolithographic layer a first pattern is ated on a first plane light modulator. The first plane light modulator comprises a plurality of picture elements, and the first pattern is defined by a prescribed number of addressed picture elements. Then a second pattern is created on a second plane light modulator. The second plane light modulator comprises a plurality of picture elements, and the second pattern has a first region of addressed picture elements, which matches the first pattern or part thereof, and immediately adjacent to this a second region of addressed picture elements. Finally the first and the second pattern are imaged onto a region to be exposed of the layer to be structured.

Claims

1. A method for structuring a photolithographic layer, comprising the following steps:

a) creating a first pattern on a first plane light modulator, where the first plane light modulator comprises a plurality of picture elements, where the first pattern is defined by a prescribed number of addressed picture elements;

b) imaging the first pattern onto a region to be exposed of the layer to be structured;

c) creating a second pattern on a second plane light modulator, where the second plane light modulator comprises a plurality of picture elements, where the second pattern comprises a first region of addressed picture elements, which matches the first pattern or part thereof, and immediately adjacent to the first region a second region of addressed picture elements; and

d) imaging the second pattern onto the region to be exposed of the layer to be structured;

wherein the first and the second pattern are imaged simultaneously onto the region to be exposed of the layer to be structured; and

wherein said first pattern is imaged with a first intensity and said second pattern is imaged with a second intensity, said first and second intensities being below the intensities necessary to image the complete first pattern and the complete second pattern.

2. A method according to claim 1, wherein the second region of the second pattern comprises an addressed picture element at right angles to an extension direction of the first region of the second pattern.

3. A method according to claim 1, wherein the first and the second plane light modulator are illuminated by a light source.

4. A method according to claim 3, wherein a difference in the light paths from the light source via the first and the second plane light modulator to the layer to be structured is less than a coherence length of the light of the light source.

5. A method according to claim 1, wherein the first and the second plane light modulator are illuminated by a first and a second light source, where the first and the second light source interfere with each other.

6. A method according to claim 5, wherein a difference in the light paths from the first light source via the first plane light modulator and from the second light source via the second plane light modulator to the layer to be structured is less than a coherence length of the light of the light sources.

7. A device for structuring a photolithographic layer, comprising:

a first plane light modulator with a plurality of picture elements for creating a first pattern, which is defined by a prescribed number of addressed picture elements;

an imaging device, which images the first pattern onto a region to be exposed of the layer to be structured; and

a second plane light modulator with a plurality of picture elements for creating a second pattern, which comprises a first region of addressed picture elements, which matches the first pattern or part thereof, and immediately adjacent to the first region a second region of addressed picture elements;

wherein the imaging device images the second pattern onto the region to be exposed of the layer to be structured;

wherein the imaging device images the first and the second pattern simultaneously onto the region to be exposed of the layer to be structured; and

wherein said first pattern is imaged with a first intensity and said second pattern is imaged with a second intensity, said first and second intensities being below the intensities necessary to image the complete first pattern and the complete second pattern.

8. A device according to claim 7, wherein the second region of the second pattern has an addressed picture element at right angles to an extension direction of the first region of the second pattern.

9. A device according to claim 7, further comprising a first light source, which is assigned to the first plane light modulator;

and

a second light source, which is assigned to the second plane light modulator, whose light can interfere with the light of the first light source.

10. A device according to claim 9, wherein a difference in the light paths from the first light source via the first plane light modulator and from the second light source via the second plane light modulator to the layer to be structured is less than a coherence length of the light of the light sources.

11. A device according to claim 7, comprising a light source;

and

a beam splitting device which directs the light beam from the light source onto the first and onto the second plane light modulator.

12. A device according to claim 11, wherein a difference in the light paths from the light source via the first and the second plane light modulator to the layer to be structured is less than a coherence length of the light of the light source.

13. A device according to claim 11, wherein the beam splitting device splits the light beam from the light source into two beams of equal light intensity.

14. A device according to claim 9, wherein the light source is a pulsed laser light source.

15. A device according to claim 7, comprising a movable positioning table, on which the layer to be structure can be mounted.