Lithographic apparatus and device manufacturing method

• US 20060109435A1
• Filed: 12/29/2005
• Published: 05/25/2006
• Est. Priority Date: 04/16/2004
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Bleeker, Arno J.
• Granted Patent: US 7,388,650 B2
• Time in Patent Office: Days
• US Class Current: 355/18
• 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

Abstract

A lithographic apparatus includes a patterning device that patterns a projected beam. The patterning device includes an array of cells that contain a polar fluid, a non-polar fluid, and an electrode. A potential difference across the electrode and the polar fluid causes displacement of the non-polar fluid. Based on a difference in refractive index between the polar fluid and the non-polar fluid, a beam of light which passes through the cell will have its phase changed in dependence on the relative thickness on the polar and non-polar fluids and on their refractive indices.

Claims

1. A patterning array of individually controllable elements, the individually controllable elements comprising:

a cell;

a polar fluid located in the cell;

a non-polar fluid located in the cell; and

an electrode coupled to the polar fluid and to a voltage source.

2. The patterning array of claim 1, wherein the polar fluid, the non-polar fluid, the electrode, and the voltage source are arranged to selectively apply an electric field across the cell for voltage-controlled displacement of the non-polar fluid within the cell.

3. The patterning device of claim 1, wherein the polar fluid and the non-polar fluid have substantially the same transmissivity, but different refractive indices.

4. The patterning device of claim 1, wherein the polar and non-polar fluids are configured to change a phase of part of a bean of radiation passing therethrough by a predetermined amount relative to other parts of the beam depending on a level of applied voltage by the voltage source.

5. The patterning device of claim 4, wherein the polar and non-polar fluids change the phase of the beam in accordance with:

Δ

φ

=2π

d/λ

(n1−

n2)

wherein

Δ

φ

=change in phase,

d=a thickness of the non-polar fluid,

λ

=wavelength of the radiation beam,

n1=refractive index of the non-polar fluid, and

n2=refractive index of the polar fluid.

6. The patterning device of claim 1, wherein the polar fluid is water.

7. The patterning device of claim 1, wherein the non-polar fluid is oil.

8. The patterning device of claim 1, wherein the cell comprises a reflective surface on an opposite inside surface of the cell from a radiation entry surface and is configured so that a beam of radiation entering the cell travels through the cell twice.

9. The patterning device of claim 1, further comprising:

an insulating layer that insulates the electrode from the polar and non-polar fluids.

10. The patterning device of claim 1, wherein the polar and non-polar fluids are configured to change a phase of part of a beam of radiation passing therethrough by a predetermined amount relative to other parts of the beam using an electrowetting technique.

11. A method, comprising:

forming a first shape of boundary regions between polar and non-polar liquids within respective cells in an array of cells during a first state;

applying a potential across one or more of the cells to form corresponding second shapes of the boundary regions during a second state; and

changing a phase of respective portions of a beam of radiation passing through respective ones of the cells in the second state based on the second shapes.