Maskless optical writer

• US 20060119827A1
• Filed: 01/24/2006
• Published: 06/08/2006
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Sewell, Harry
• Granted Patent: US 7,548,301 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: A61B 6/4435 the source unit and the detector unit being coupled by a rigid structure
• 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 7/70566 Polarisation control

Abstract

A maskless pattern generating system for use in lithographic processing includes a liquid crystal pixel array. The system generates a light beam and applies a voltage level to each pixel of the pixel array to modulate a polarization state of the light beam so as to create a pattern image. The voltage levels correspond to greyscale levels assigned to the pixels. The system can receive a control signal input based on pattern information that defines the pattern image. The setting of the individual voltage levels can allow the liquid crystal pixel array to act as a phase shift mask, can allow the pattern image to be shifted, and can allow the manipulation of a pattern image edge. This maskless pattern writing system acts as a light valve to control pattern imagery, on a pixel by pixel basis, for the purposes of direct writing patterns.

Claims

1. A method of generating a pattern for use in a maskless lithographic processing system using a pixel array of a liquid crystal programmable pattern generator having a plurality of pixels, comprising:

generating a light beam; and

applying a voltage level to each pixel of the pixel array to thereby modulate a polarization state of the light beam so as to create a pattern image, wherein an individual voltage level corresponds to a greyscale level assigned to a particular one of the plurality of pixels.

2. The method of claim 1, further comprising:

receiving a control signal input from a controller based on pattern information provided to the controller, the control signal input defining the pattern image.

3. The method of claim 1, wherein the generating a light beam comprises:

originating the light beam; and

reflecting the light beam toward the liquid crystal pixel array.

4. The method of claim 1, wherein the generating a light beam comprises:

originating the light beam; and

polarizing the light beam.

5. The method of claim 4, wherein the polarizing the light beam comprises:

polarizing the light beam with a polarizer.

6. The method of claim 4, wherein the polarizing the light beam comprises:

polarizing the light beam with a polarizing beam splitter.

7. The method of claim 1, further comprising:

polarizing the pattern image.

8. The method of claim 1, wherein the applying a voltage level comprises phase-shifting the pattern image by setting the individual voltage levels past one cycle of light.

9. The method of claim 1, wherein the applying a voltage level comprises shifting the pattern image by shifting settings of the individual voltage levels in one direction by the same number of pixel rows.

10. The method of claim 1, wherein the applying a voltage level comprises manipulating the edge of the pattern image by setting the individual voltage levels corresponding to individual pixels that are one of:

part of an edge of the pattern image; and

a pixel row beyond pixels that are part of the edge of the pattern image.

11. The method of claim 1, wherein the applying a voltage level to each pixel of the pixel array comprises applying one of:

a maximum voltage;

no voltage; and

a percentage of the maximum voltage.

12. A method of performing maskless lithography using the method of claim 1, and further comprising:

reducing the pattern image with reduction optics for projection onto a substrate;

positioning the substrate relative to the reduction optics; and

projecting the pattern image onto the substrate.

13. The method of claim 12, wherein the reducing the pattern image comprises:

reflecting the light beam from the liquid crystal programmable pattern generator through a polarizing beam splitter toward the reduction optics.

14. An integrated circuit device manufactured according to the method of claim 12.

15. A flat panel display manufactured according to the method of claim 12.

16. A maskless pattern generating system for use in a lithographic processing system, the maskless pattern generating system including a liquid crystal pixel array of a plurality of pixels and comprising:

means for generating a light beam; and

means for applying a voltage level to each pixel of the pixel array to thereby modulate a polarization state of the light beam so as to create a pattern image, wherein an individual voltage level corresponds to a greyscale level assigned to a particular one of the plurality of pixels.

17. The maskless pattern generating system of claim 16, further comprising:

means for receiving a control signal input from a controller based on pattern information provided to the controller, the control signal input defining the pattern image.

18. The maskless pattern generating system of claim 16, wherein the means for generating a light beam comprises:

means for originating the light beam; and

means for reflecting the light beam toward the liquid crystal pixel array.

19. The maskless pattern generating system of claim 16, wherein the means for generating a light beam comprises:

means for originating the light beam; and

means for polarizing the light beam.

20. The maskless pattern generating system of claim 19, wherein the means for polarizing the light beam comprises a polarizer.

21. The maskless pattern generating system of claim 19, wherein the means for polarizing the light beam comprises a polarizing beam splitter.

22. The maskless pattern generating system of claim 16, further comprising:

means for polarizing the pattern image.

23. The maskless pattern generating system of claim 16, wherein the means for applying a voltage level is operable to phase shift the pattern image by setting the individual voltage levels past one cycle of light.

24. The maskless pattern generating system of claim 16, wherein the means for applying a voltage level is operable to shift the pattern image by shifting the settings of the individual voltage levels in one direction by the same number of pixel rows.

25. The maskless pattern generating system of claim 16, wherein the means for applying a voltage level is operable to manipulate an edge of the pattern image by setting the individual voltage levels corresponding to individual pixels that are one of:

part of the edge of the pattern image; and

a pixel row beyond pixels that are part of the edge of the pattern image.

26. The maskless pattern generating system of claim 16, wherein the means for applying a voltage level to each pixel of the pixel array applies one of:

a maximum voltage;

no voltage; and

a percentage of the maximum voltage.

27. A maskless lithography system including the maskless pattern generating system of claim 16, and further comprising:

means for reducing the pattern image for projection onto a substrate;

means for positioning the substrate relative to the means for reducing the pattern image; and

means for projecting the pattern image onto the substrate.

28. A device manufacturing method, comprising:

providing a pattern generating system including a liquid crystal pixel array of a plurality of pixels, the pattern generating system operable to

generate a light beam, and

apply a voltage level to each pixel of the pixel array to thereby modulate a polarization state of the light beam so as to create a pattern image, wherein an individual voltage level corresponds to a greyscale level assigned to a particular one of the plurality of pixels;

providing means to support a substrate;

providing means to project the pattern image onto the substrate; and

providing means to position the substrate relative to the means to project the pattern image.