Pattern generator

• US 7,800,815 B2
• Filed: 10/31/2007
• Issued: 09/21/2010
• Est. Priority Date: 03/02/1998
• Status: Expired due to Fees

• Current Assignee: Micronic Laser Systems AB (Mycronic AB)
• Original Assignee: Micronic Laser Systems AB (Mycronic AB)
• Inventors: Sandstrom, Torbjorn
• Primary Examiner(s): Choi; William C
• Application Number:
  US11/980,423
• Publication Number:
  US 20080079922A1
• Time in Patent Office: 1,056 Days
• Field of Search: 359/198, 359/212, 359/214, 359/223, 359290-292, 359/298, 359/198.1, 359/212.1, 359/214.1, 359/223.1, 355/53, 355/67, 430/22, 430/395, 347/134, 347/224, 347/225, 347/233, 347/239
• US Class Current: 359/298
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/0648 comprising lenses
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/0043 in projection exposure systems, e.g. microlithographic systems
• CPC Class Codes: G02B 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G03F 7/2022 Multi-step exposure, e.g. hybrid; backside exposure; blanket exposure, e.g. for image reversal; edge exposure, e.g. for edge bead removal; corrective exposure
• CPC Class Codes: G03F 7/70041 by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• 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 7/704 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
• CPC Class Codes: G03F 7/70475 Stitching, i.e. connecting image fields to produce a device field, the field occupied by a device such as a memory chip, processor chip, CCD, flat panel display
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: H04N 1/195 the array comprising a two-dimensional array or a combination of two-dimensional arrays
• CPC Class Codes: H04N 2201/0414 Scanning an image in a series of overlapping zones
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]

Abstract

The present invention relates to an apparatus for creating a pattern on a workpiece sensitive to radiation, such as a photomask a display panel or a microoptical device. The apparatus may include a source for emitting light flashes, a spatial modulator having modulating elements (pixels), adapted to being illuminated by the radiation, and a projection system creating an image of the modulator on the workpiece. It may further include an electronic data processing and delivery system receiving a digital description of the pattern to be written, converting the pattern to modulator signals, and feeding the signals to the modulator. An electronic control system may be provided to control a trigger signal to compensate for flash-to-flash time jitter in the light source.

Claims

1. A method of optical printing using an SLM in a system including an optical system for projecting an image of the SLM onto a workpiece that is positioned on a moving stage, the method comprising:

selectively illuminating portions of the SLM, a first part of the SLM being loaded with data while a second part of the SLM is illuminated;

scanning the SLM at a repetition rate of greater than or equal to 100 kHz; and

printing a pattern on the workpiece with radiation modulated using the SLM.

2. The method of claim 1, wherein the printing on the workpiece occurs as the moving stage transports the workpiece relative to the projected image of the SLM.

3. The method of claim 2, wherein the SLM is a two dimensional array rotated so that a coordinate system of the SLM is not parallel to a direction of relative motion of the workpiece during the printing.

4. The method of claim 3, wherein the coordinate system of the SLM is rotated 45 degrees to the direction of the relative motion of the workpiece.

5. The method of claim 1, wherein the SLM is scanned using a continuous laser source.

6. The method of claim 1, further including, controlling the scanning of the SLM using an electro-optic scanner.

7. The method of claim 1, wherein the SLM is a micro-mirror array.

8. The method of claim 1, further including, controlling the scanning of the SLM using an acousto-optic scanner.

9. A method of optical printing using an SLM in a system including an optical system for projecting an image of the SLM onto a workpiece that is positioned on a moving stage, the method comprising:

selectively illuminating portions of the SLM, a first part of the SLM being loaded with data while a second part of the SLM is illuminated; and

printing a pattern on the workpiece with radiation modulated using the SLM; and

controlling the scanning of the SLM using an acousto-optic scanner.

10. An apparatus for a system including an optical system for projecting an image of a spatial light modulator (SLM) onto a workpiece that is positioned on a moving stage, the workpiece being printed with radiation modulated using the SLM, the apparatus comprising:

a continuous laser source configured to emit a continuous laser; and

an electro-optic scanner configured to scan the continuous laser over the SLM such that the SLM is uniformly illuminated;

wherein

said electro-optic scanner is an electro-optic and acousto-optic scanner.

11. The apparatus of claim 10, wherein said SLM is a matrix of pixels with only a few lines of pixel elements in at least one direction.

12. The apparatus of claim 10, wherein the continuous laser is a continuous ultra-violet (UV) laser.

13. The apparatus of claim 10, further comprising:

an optical system configured to project an image of the SLM onto the workpiece positioned on the moving stage to expose the workpiece.

14. An apparatus for a system including an optical system for projecting an image of a spatial light modulator (SLM) onto a workpiece that is positioned on a moving stage, the workpiece being printed with radiation modulated using the SLM, the apparatus comprising:

a continuous laser source configured to emit a continuous laser; and

an electro-optic scanner configured to scan the continuous laser over the SLM such that the SLM is uniformly illuminated;

wherein

the pixels in the SLM are analog modulated.

15. The apparatus of claim 14, wherein said SLM is a matrix of pixels with only a few lines of pixel elements in at least one direction.

16. The apparatus of claim 14, wherein the continuous laser is a continuous ultra-violet (UV) laser.

17. The apparatus of claim 14, further comprising:

an optical system configured to project an image of the SLM onto the workpiece positioned on the moving stage to expose the workpiece.

18. An apparatus for a system including an optical system for projecting an image of a spatial light modulator (SLM) onto a workpiece that is positioned on a moving stage, the workpiece being printed with radiation modulated using the SLM, the apparatus comprising:

a continuous laser source configured to emit a continuous laser; and

an electro-optic scanner configured to scan the continuous laser over the SLM such that the SLM is uniformly illuminated;

wherein

the continuous laser is scanned over the SLM at a repetition rate of greater than or equal to 100 kHz.

19. The apparatus of claim 18, wherein said SLM is a matrix of pixels with only a few lines of pixel elements in at least one direction.

20. The apparatus of claim 18, wherein the continuous laser is a continuous ultra-violet (UV) laser.

21. The apparatus of claim 18, further comprising:

an optical system configured to project an image of the SLM onto the workpiece positioned on the moving stage to expose the workpiece.