Laser pattern generation apparatus

• US 4,796,038 A
• Filed: 03/28/1988
• Issued: 01/03/1989
• Est. Priority Date: 07/24/1985
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: ATEQ Corporation (Applied Materials Incorporated)
• Inventors: Allen, Paul C., Warkentin, Paul A.
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US07/178,868
• Time in Patent Office: 281 Days
• Field of Search: 354/4, 354/5, 346/76 L, 346/108, 346/160, 355/53, 219/121.76-121.83, 358/302, 369/121, 369/125
• US Class Current: 396/548
• CPC Class Codes: G03F 7/704 Scanned exposure beam, e.g. raster-, rotary- and vector scanning mask projection exposure involving relative movement of patterned beam and workpiece during imaging G03F7/70358

Abstract

A laser pattern generation apparatus particularly suited for semiconductor applications. The laser beam is split into a plurality of beams and modulated with acousto-optic modulators. A rotating mirror having a plurality of facets causes the beam to scan the workpiece.

Claims

1. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:

a laser for providing a radiant energy beam;

beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;

modulation means for independently modulating each of said plurality of beams, said modulation means being optically coupled to said beam splitting means;

rotating mirror having a plurality of facets for causing said beams to scan said workpiece, said beams from said modulation means being directed onto said rotating mirror;

focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece;

a part holder for receiving said workpiece;

a steering mirror for adjusting the position of said beams on said rotating mirror during operation of said apparatus to compensate for movement between said partholder and said beams, said steering mirror being optically disposed between said modulation means and said rotating mirror;

movement detection means for detecting movement of said partholder, said movement detection means for providing information for adjustment of said steering mirror relative to movement of said partholder during scanning of said workpiece;

whereby a pattern is generated on said workpiece.

2. The apparatus defined by claim 1 including optical means for providing an enlarged image plane between said rotating mirror and said workpiece.

3. The apparatus defined by claim 2 wherein said optical means includes a beam splitter in said enlarged image plane for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror.

4. The apparatus defined by claim 3 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to a detector to provide an indication of the position of said workpiece.

5. The apparatus defined by claim 2 wherein said optical means includes and F-theta lens.

6. The apparatus defined by claim 1 including a dove prism disposed between said modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.

7. The apparatus defined by claim 1 including a zoom lens disposed between said modulation means and said rotating mirror.

8. The apparatus defined by claim 1 or claim 4 wherein said modulation means comprises an acousto-optical device.

9. The apparatus defined by claim 1 wherein said beam splitting means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.

10. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:

at least one laser for providing radiant energy beams;

a splitting and modulation means for receiving said beam from said laser and for providing a plurality of modulated laser beams;

rotating mirror having a plurality of facets, said beams from said modulation means being directed onto said rotating mirror;

focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece, said focusing means including optical means for providing an enlarged image plane between said rotating mirror and said workpiece;

a beam splitter in said enlarged image plane for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror;

calibration and position detection means optically coupled with said workpiece for providing calibration and position detection information;

whereby said rotating mirror causes said plurality of beams to scan said workpiece.

11. The apparatus defined by claim 10 wherein said splitting and modulation means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.

12. The apparatus defined by claim 10 wherein said optical means for providing said enlarged image plane includes an F-theta lens.

13. The apparatus defined by claim 10 including a dove prism disposed between said modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.

14. The apparatus defined by claim 10 including a zoom lens disposed between said modulation means and said rotating mirror.

15. The apparatus defined by claim 10 including a steering mirror disposed between said modulation means and said rotating mirror for adjusting the position of said beams on said rotating mirror to compensate for movement between said workpiece and said beams.

16. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:

a laser for providing a radiant energy beam;

beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;

acousto-optic modulation means for independently modulating each of said plurality of beams, said modulation means being optically coupled to said beam splitting means;

rotating mirror having a plurality of facets, said beams from said modulation means being directed onto said rotating mirror;

focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece;

a partholder for receiving said workpiece said partholder being mounted for movement in a direction perpendicular to said scan direction;

a steering mirror disposed between said modulation means and said rotating mirror, said beams striking said steering mirror at a focal point with respect to said pattern image on said workpiece to compensate for relative beam-workpiece movement in said direction perpendicular to said scan direction;

movement detection means for detecting movement of said partholder, said movement detection means for providing information for adjustment of said steering mirror relative to non-constant velocity partholder movement during scanning of said workpiece;

whereby said rotating mirror and said partholder movement causes said workpiece to be raster scanned in a predetermined path in said direction perpendicular to said scan direction and said steering mirror to adjusts said beams to compensate for nonconstant velocity movement of said partholder.

17. The apparatus defined by claim 16 wherein said partholder is mounted on a table which moves in said scan direction.

18. The apparatus defined by claim 17 incuding a beam splitter for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror.

19. The apparatus defined by claim 16 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by a beam splitter to provide an indication of the position of said workpiece.

20. The apparatus defined by claim 16 or 19 including a fourth mirror mounted for movement with said partholder and a first interferometer to permit detection of movement of said partholder in said direction perpendicular to said scan direction.

21. The apparatus defined by claim 20 including a fifth mirror mounted for movement with said partholder and a second interferometer to permit detection of movement of said partholder in said scan direction.

22. The apparatus defined by claim 16 including an enlarged image plane between said rotating mirror and said workpiece.

23. The apparatus defined by claim 22 including a beam splitter in said enlarged image plane for reflecting one of said beams from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror, said one beam being turned on prior to said beams scanning said workpiece.

24. The apparatus defined by claim 23 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to provide an indication of the position of said workpiece.

25. The apparatus defined by claim 22 wherein for said enlarged image plane includes an F-theta lens.

26. The apparatus defined by claim 16 including a dove prism disposed between said acousto-optic modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.

27. The apparatus defined by claim 16 including a zoom lens disposed between said acousto-optic modulation means and said rotating mirror.

28. The apparatus defined by claim 16 wherein said beam splitting means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.