Light patterning device using tilting mirrors in a superpixel form

• US 20060245033A1
• Filed: 04/28/2005
• Published: 11/02/2006
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Bleeker, Arno Jan, Troost, Kars Zeger, Baba-Ali, Nabila
• Granted Patent: US 7,400,382 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• 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: 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 7/70308 Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
• 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 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]

Abstract

A light patterning system comprises an illumination system that supplies a beam of radiation having a certain wavelength (λ). An array of reflective pixels patterns the beam, wherein the array includes pixels having at least a first tilting mirror that is logically coupled to a second tilting mirror. In an embodiment, the first and second tilting mirrors are (i) substantially adjacent to each other; and (ii) offset in height from each other by a first mirror displacement. A projection system is included that projects the patterned beam onto a target. In alternate embodiment, the array of reflective pixels includes pixels having first through fourth tilting mirrors that are logically coupled to each other. The first through fourth tilting mirrors are (i) respectively offset in height from a reference plane by first through fourth mirror displacements, and (ii) are respectively arranged clockwise in a substantially square pattern.

Claims

1. A light patterning system, comprising:

an illumination system that supplies a beam of radiation having a certain wavelength (λ

);

an array of individually controllable elements that patterns said beam, wherein said array includes a superpixel having at least a first tilting mirror that is logically coupled to a second tilting mirror, and wherein said first and second tilting mirrors are (i) substantially adjacent to each other, and (ii) offset in height from each other by a first mirror displacement, and

a projection system that projects said patterned beam onto a target.

2. The system of claim 1, wherein said first mirror displacement is some fraction of λ

.

3. The system of claim 1, wherein said first mirror displacement is selected from the group consisting of zero, λ

/4, or λ

/8.

4. The system of claim 1, wherein said first and second tilting mirrors respectively have programmable first and second tilt angles, thereby permitting a superpixel including said first and second tilting mirrors to reflect the beam of radiation with a selected grayscale and phase.

5. The system of claim 4 wherein when said first and second tilting mirrors are at rest, said first and second tilting mirrors are in a position of maximum reflectivity.

6. The system of claim 1, wherein each of said tilting mirrors is a flat-tilting mirror.

7. The system of claim 1, wherein each of said tilting mirrors is phase-stepped mirror.

8. The system of claim 7, wherein when said first and second tilting mirrors are at rest, said first and second tilting mirrors are in a position of minimum reflectivity.

9. The system of claim 1, wherein said first and second tilting mirrors forming said pixel are selected from amongst a plurality of such tilting mirrors to form said pixel depending on the location of a feature to patterned on said target.

10. A light patterning system, comprising:

an illumination system that supplies a beam of radiation having a certain wavelength (λ

);

an array of reflective pixels that patterns said beam, wherein said array includes pixels having first through fourth tilting mirrors that are logically coupled to each other, and wherein said first through fourth tilting mirrors are respectively (i) arranged in a substantially square pattern, and (ii) offset in height from a reference plane by first through fourth mirror displacements; and

a projection system that projects said patterned beam onto a target.

11. The system of claim 10, wherein said mirror displacements are balanced such that said first mirror displacement is substantially equal to said third mirror displacement, and said second mirror displacement is substantially equal to said fourth mirror displacement.

12. The system of claim 11, wherein said first and third mirror displacements are zero, while said second and fourth mirror displacements are λ

/4.

13. The system of claim 11, wherein said first and third mirror displacements are zero, while said second and fourth mirror displacements are λ

/8.

14. The system of claim 12, wherein said first through fourth mirror displacements are zero.

15. The system of claim 10, wherein said first through fourth mirror displacements are different from each other.

16. The system of claim 15, wherein said first through fourth mirror displacements are less than ⅛

λ

.

17. The system of claim 15, wherein said first mirror displacement is zero, said second mirror displacement is λ

/8, said third mirror displacement is λ

/4, and said fourth mirror displacement is 3λ

/8.

18. The system of claim 10, wherein said first through fourth tilting mirrors respectively have programmable first through fourth tilt angles, thereby permitting a superpixel including said first through fourth tilting mirrors to reflect the beam of radiation with selected grayscale and phase.

19. The system of claim 18, wherein said tilt angles are balanced such that said first tilt angle is substantially equal to said third tilt angle, while said second tilt angle is substantially equal to said fourth tilt angle.

20. The system of claim 18, wherein said first through fourth tilt angles are different from each other.

21. The system of claim 18, wherein when said first through fourth tilting mirrors are at rest, said first through fourth tilting mirrors are in a position of maximum reflectivity.

22. The system of claim 10, wherein each of said tilting mirrors is a flat-tilting mirror.

23. The system of claim 10, wherein each of said tilting mirrors is phase-stepped mirror.

24. The system of claim 23, wherein when said first through fourth tilting mirrors are at rest, said first through fourth tilting mirrors are in a position of minimum reflectivity.

25. The system of claim 10, wherein said first through fourth tilting mirrors are selected from amongst a plurality of such tilting mirrors to form said superpixel depending on the location of a feature to patterned on said target.

26. A method for patterning a beam of radiation, comprising:

patterning a beam of radiation having a wavelength (λ

) using an array of reflective pixels, wherein said array includes superpixels having at least a first tilting mirror that that is logically coupled to a second tilting mirror, and wherein said first and second tilting mirrors are (i) offset in height from each other by a first mirror displacement, and (ii) substantially adjacent to each other; and

projecting the patterned beam onto a target portion of an object.

27. The method of claim 26, wherein said first and second mirror respectively have a first and second tilt angle, the method further comprising programmably selecting said first and second tilt angles so that said pixel reflects the beam of radiation with a selected grayscale and phase.

28. The method of claim 26, further comprising emulating at least one of a binary mask, attenuating phase shift mask, and alternating phase shift mask using said superpixels.

29. The method of claim 26, further comprising selecting said first and second tilting mirrors from amongst a plurality of such tilting mirrors, depending on the location of a feature to patterned on said target.