MICROPHOTONIC MASKLESS LITHOGRAPHY

• US 20080014534A1
• Filed: 07/11/2007
• Published: 01/17/2008
• Est. Priority Date: 07/11/2006
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Barwicz, Tymon, Popovic, Milos
• Granted Patent: US 8,105,758 B2
• Time in Patent Office: Days
• US Class Current: 430/327
• CPC Class Codes: G03F 7/70383 Direct write, i.e. pattern is written directly without the use of a mask by one or multiple beams maskless lithography using a programmable mask G03F7/70291

Abstract

A maskless lithography system and method to expose a pattern on a wafer by propagating a photon beam through a waveguide on a substrate in a plane parallel to a top surface of the wafer.

Claims

1. A maskless lithography system for exposing a pattern on a wafer, the system comprising:

a photon source for generating a photon beam; and

a waveguide, disposed on a substrate, for propagating the photon beam in a plane parallel to a top surface of the wafer.

2. The maskless lithography system of claim 1, further comprising:

an in-plane modulator for modulating the photon beam propagating in the plane parallel to the top surface of the wafer.

3. The maskless lithography system of claim 1, further comprising:

an output vertical coupler for redirecting the photon beam from an in-plane direction to an out-of-plane direction towards the top surface of the wafer.

4. The maskless lithography system of claim 3, further comprising:

a focusing element for focusing the photon beam propagating in the out-of-plane direction onto the top surface of the wafer.

5. The maskless lithography system of claim 4, wherein the output vertical coupler and the focusing element form a single integrated optical device.

6. The maskless lithography system of claim 3, further comprising:

an input vertical coupler,

wherein the photon source comprises an external photon source and the input vertical coupler couples the external photon source to the waveguide.

7. The maskless lithography system of claim 1 wherein the photon beam comprises a plurality of wavelength channels.

8. The maskless lithography system of claim 7, further comprising:

a wavelength demultiplexer, disposed in a plane parallel to the top surface of the wafer, for demultiplexing the photon beam,

wherein the system comprises a plurality of the waveguides for guiding the demultiplexed photon beams from the wavelength demultiplexer.

9. The maskless lithography system of claim 7, further comprising:

a multi-wavelength vertical coupler for redirecting the photon beam from an in-plane direction to an out-of-plane direction.

10. The maskless lithography system of claim 9 wherein the multi-wavelength vertical coupler for redirecting a plurality of wavelength channels constituting the photon beam from an in-plane direction to a plurality of out-of-plane directions that are substantially different for at least two wavelength channels.

11. The maskless lithography system of claim 9 wherein the multi-wavelength vertical coupler for focusing at least two of the wavelength channels on substantially different positions on the top surface of the wafer.

12. The maskless lithography system of claim 1 wherein a wavelength of the photon beam is selected from a range of 150 nanometers to 1000 nanometers.

13. The maskless lithography system of claim 1, wherein the photon source generates a plurality of the photon beams.

14. The maskless lithography system of claim 1, further comprising a beam separator for splitting the photon beam into a plurality of output photon beams.

15. The maskless lithography system of claim 14, wherein the beam separator is selected from the group consisting of a power splitter, a demultiplexer, a multi-wavelength vertical coupler, and combinations thereof.

16. A method for exposing a pattern on a wafer, the method comprising the steps of:

forming a thin photon-sensitive film over a top surface of the wafer; and

exposing at least a portion of the photon-sensitive film by propagating a photon beam in a waveguide on a substrate in a plane parallel to the top surface of the wafer and redirecting the photon beam from an in-plane to an out-of-plane direction towards the portion of the thin photon-sensitive film.

17. The method of claim 16, wherein the photon beam is redirected by an output vertical coupler.

18. The method of claim 17, wherein the output vertical coupler redirects the photon beam from an in-plane direction to an out-of-plane direction and focuses the photon beam on the wafer.

19. The method claim 17 wherein the output vertical coupler comprises a multi-wavelength vertical coupler.

20. The method of claim 16, further comprising modulating the photon beam in a plane parallel to the top surface of the wafer.

21. The method of claim 16 wherein the photon beam is provided by an external photon source.

22. The method of claim 16, wherein the photon beam is provided in a maskless lithography system, the maskless lithography system comprises an input vertical coupler, and the photon beam is coupled from the external photon source to the waveguide with the input vertical coupler.

23. The method of claim 16, wherein the photon beam comprises a plurality of wavelength channels.

24. The method of claim 23, wherein the maskless lithography system comprises a wavelength demultiplexer, disposed in a plane parallel to the top surface of the wafer, for demultiplexing the photon beam, and a plurality of the waveguides for guiding the demultiplexed photon beams from the wavelength demultiplexer to a plurality of output vertical couplers.

25. A method for exposing a pattern on a wafer, the method comprising the steps of:

forming a thin photon-sensitive film over a top surface of the wafer; and

propagating a photon beam in a waveguide on a substrate in a plane parallel to the top surface of the wafer and redirecting the photon beam to a vertical path towards the photon-sensitive film to expose at least a portion thereof, thereby substantially reproducing a predetermined pattern.