Methods, Systems, and Computer Program Products for Printing Patterns on Photosensitive Surfaces

• US 20080079923A1
• Filed: 08/09/2007
• Published: 04/03/2008
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Mast, Karel, Latypov, Azat
• Granted Patent: US 7,777,861 B2
• Time in Patent Office: Days
• US Class Current: 355/71
• CPC Class Codes: G03B 27/54 Lamp housings; Illuminating means
• 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 7/70475 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

Abstract

A method, system, and computer program product are provided for printing a pattern on a photosensitive surface using a maskless lithography system including a spatial light modulator (SLM). The method, system, and computer program product define two or more exposure areas within a predetermined region of the surface, each area corresponding to selected pixels of the SLM. An overlap region is formed between the two or more exposure areas, the overlapping region being defined by respective overlapping edges of the exposure areas, the overlapping edges corresponding to overlapping pairs of the selected pixels from each area. The pixels within each pair are alternately activated such that only one of the pixels within the pair is used to produce the pattern.

Claims

1. An lithographic apparatus, comprising:

an illumination system configured to produce a beam of radiation;

an array of individually programmable elements configured to pattern the beam of radiation;

a projection system configured to project the patterned beam onto first and second overlapping target portions of a substrate, the first and second target portions corresponding to respective overlapping pairs of elements in the array of individually programmable elements, and

a controller configured to control the array of individually controllable elements, such that a first one of the elements within the pair produces a pattern during a first exposure period and a second one of the elements within the pair produces a pattern during a second exposure period.

2. The lithographic apparatus of claim 1, wherein the controller is configured to turn on the first one of elements of the pair, while substantially simultaneously turning off the second one of the elements of the pair.

3. The lithographic apparatus of claim 1, wherein the controller is configured to control the array of individually programmable elements to alternatingly activate alternating pairs of the elements corresponding to different portions of the overlapping target portions, such that the alternating pairs of the elements form an alternating pattern stitching area.

4. The lithographic apparatus of claim 3, wherein the alternating pairs form a checkerboard pattern.

5. The lithographic apparatus of claim 1, wherein the pattern is representative of an oscillating stitching line.

6. The lithographic apparatus of claim 1, wherein the controller is configured to redistribute the pattern within the overlapping region.

7. The lithographic apparatus of claim 6, wherein controller is configured to spatially average stitching disturbances during the redistributing of the pattern.

8. A computer program product comprising a computer usable medium having control logic stored therein for causing a computer to print a pattern on a photosensitive surface, comprising:

a first computer readable program code means for causing the computer to define two or more exposure areas within a predetermined region of a photosensitive surface, each area corresponding to selected pixels of a spatial light modulator;

a second computer readable program code means for causing the computer to form an overlapping region between the two or more exposure areas, the overlapping region being defined by respective overlapping edges of the exposure areas, each overlapping edge corresponding to at least one overlapping pair of the selected pixels from each area; and

a third computer readable program code means for causing the computer to alternately activate the pixels within the pair such that only one of the pixels within the pair produces a pattern during one exposure and only the other pixel within the pair produces the pattern during an ensuing exposure.

9. The computer program product of claim 8, wherein third computer readable program code comprises means for causing the computer to turn one pixel on and substantially simultaneously turn the other pixel off.

10. The computer program product of claim 8, wherein the second computer readable program code comprises means for causing the computer to distribute opposite alternating pairs throughout the overlapping region such that the alternating pairs form an alternating pattern stitching area.

11. The computer program product of claim 10, wherein the alternating pairs form a checkerboard pattern.

12. The computer program product of claim 8, wherein the pattern is representative of an oscillating stitching line.

13. The computer program product of claim 8, wherein the control logic further comprises a fourth computer readable program code means for causing the computer to redistribute the pattern within the overlapping region to spatially average stitching disturbances.

14. A computer-readable medium containing instructions for controlling at least one processor by a method comprising:

defining two or more exposure areas within a predetermined region of a photosensitive surface, each area corresponding to selected pixels of a spatial light modulator;

forming an overlapping region between the two or more exposure areas, the overlapping region being defined by respective overlapping edges of the exposure areas, each overlapping edge corresponding to at least one overlapping pair of the selected pixels from each area; and

alternatingly activating the pixels within the pair such that only one of the pixels within the pair produces a pattern during one exposure and only the other pixel within the pair produces the pattern during an ensuing exposure.

15. The method of claim 14, wherein the alternately activating step includes turning one pixel on and substantially simultaneously turning the other pixel off.

16. The method of claim 14, wherein opposite alternating pairs are distributed throughout the overlapping region such that the alternating pairs form an alternating pattern stitching area.

17. The method of claim 16, wherein the alternating pairs form a checkerboard pattern.

18. The method of claim 14, wherein the pattern is representative of an oscillating stitching line.

19. The method of claim 14, further comprising redistributing the pattern within the overlapping region.

20. The method of claim 19, wherein the redistributing step includes spatially averaging stitching disturbances.