Pattern generator

• US 7,710,634 B2
• Filed: 02/03/2009
• Issued: 05/04/2010
• 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:
  US12/320,713
• Publication Number:
  US 20090147345A1
• Time in Patent Office: 455 Days
• Field of Search: 359/223, 359/290, 359/292, 359/298, 250/491.1, 250/492.2, 250/492.22, 430394-396
• US Class Current: 359/290
• 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. An apparatus for creating a pattern on a workpiece sensitive to light radiation, the apparatus comprising:

a source for emitting electromagnetic radiation in a wavelength range from EUV to to IR;

a spatial light modulator (SLM) having a plurality of modulating elements operable for being illuminated by said radiation;

a projection system for creating an image of the modulator on the workpiece;

an electronic data processing and delivery system for receiving a digital description of the pattern, converting said pattern to modulator signals, and sending said signals to the modulator;

a precision mechanical system for positioning at least one of said workpiece and said projection system relative to each other; and

an electronic control system controlling the position of the workpiece, such that said pattern is printed on the workpiece;

wherein

the input pattern description is converted to modulator voltages for particular modulating elements to correct for variation among modulating elements using a lookup memory.

2. The apparatus according to claim 1, wherein the lookup memory is updated to compensate for changes in responses of the particular modulating elements.

3. The apparatus according to claim 2, wherein the lookup memory is updated iteratively.

4. The apparatus according to claim 2, wherein the changes are time dependent.

5. A method for creating a pattern on a workpiece sensitive to light radiation, the method comprising

emitting electromagnetic radiation on a spatial light modulator (SLM) having a plurality of modulating elements, the electromagnetic radiation being in a wavelength range from EUV to IR;

creating an image of the SLM on the workpiece using a projection system;

converting a received digital description of the pattern into modulator signals, the received digital description of the pattern being converted to modulator voltages for particular modulating elements to correct for variation among modulating elements using a lookup memory;

sending said signals to the modulator;

positioning at least one of said workpiece and said projection system relative to each other; and

controlling the position of the workpiece, such that said pattern is printed on the workpiece.

6. The method according to claim 5, wherein the lookup memory is updated to compensate for changes in responses of the particular modulating elements.

7. The method according to claim 6, wherein the lookup memory is updated iteratively.

8. The apparatus according to claim 7, wherein the changes are time dependent.