Lithographic apparatus and device manufacturing method utilizing a continuous light beam in combination with pixel grid imaging

• US 20070019174A1
• Filed: 07/20/2005
• Published: 01/25/2007
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Tinnemans, Patricius, De Jager, Pieter
• Granted Patent: US 7,251,019 B2
• Time in Patent Office: Days
• US Class Current: 355/55
• CPC Class Codes: G03F 7/70275 Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems
• 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 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging

Abstract

A continuous source of radiation, for example a lamp, is used in conjunction with pixel grid imaging. In one example, the individually controllable elements operate at a frequency of at least about 50 kHz. To compensate for any distortion of an exposed spot a point spread function is adjusted to be shorter in a scanning direction.

Claims

1. A lithographic apparatus, comprising:

an illumination system that supplies a continuous source radiation;

an array of individually controllable elements that modulate the radiation beam;

a substrate mover that continuously moves the substrate in a first direction relative to the radiation beam; and

a projection system that projects the modulated radiation beam onto a target portion of a substrate using,

an array of focusing elements arranged in a plane,

wherein each focusing element projects a different portion of the patterned radiation beam onto the substrate, each of the different portions forming a sub-beam of radiation, and

wherein at a focal point of at least one of the focusing elements in the array of focusing elements a maximum length of a cross-section of a corresponding one of the sub-beams of radiation is shorter in the first direction than in a second direction perpendicular to the first direction.

2. The lithographic apparatus of claim 1, wherein the cross-section of each of the sub-beams of radiation has an oblong or elliptical shape.

3. The lithographic apparatus of claim 1, wherein the focusing elements are lenses.

4. The lithographic apparatus of claim 3, wherein at least one of the lenses in the array of focusing elements is shorter in the first direction than in the second direction.

5. The lithographic apparatus of claim 1, wherein elements in the array of individually controllable elements are configured to be switched ON and OFF at a rate of at least about 50 kHz.

6. The lithographic apparatus of claim 1, further comprising a controller that sets the state of at least a portion of the individually controllable elements sequentially.

7. The lithographic apparatus of claim 6, wherein the state of the at least a portion of the individually controllable elements is set one at a time through setting one by one.

8. The lithographic apparatus of claim 6, wherein the state of the at least a portion of the individually controllable elements is set a row at a time through setting row by row.

9. The lithographic apparatus of claim 6, wherein the state of the at least a portion of the individually controllable elements is set a group at a time through setting a group of the individually controllable elements by a group of the individually controllable elements.

10. The lithographic apparatus of claim 1, wherein the continuous source of radiation is provided by a lamp.

11. The lithographic apparatus of claim 10, wherein the lamp is a Hg lamp.

12. The lithographic apparatus of claim 1, wherein spots formed on the substrate by each of the sub-beams of radiation have a point spread function, wherein altering the point spread function of the spots using the array of focusing elements allows the spots to be shorter in the first direction than in a second direction.

13. A device manufacturing method, comprising:

using an array of individually controllable elements to pattern a continuous beam of radiation;

projecting the patterned beam of radiation onto a target portion of a substrate using at least an array of focusing elements arranged in a plane, such that each focusing element in the array of focusing elements projects a different portion of the patterned radiation beam onto the substrate, each of the different portions forming a sub-beam; and

continuously moving the substrate in a first direction;

wherein the patterned radiation beam is projected such that, at a focal point of at least one of the focusing elements in the array of focusing elements, a maximum length of a cross-section of a corresponding one of the sub-beams of radiation is shorter in the first direction than in a second direction, which is perpendicular to the first direction.

14. The device manufacturing method according to claim 13, wherein a state of a portion of the array of individually controllable elements is set sequentially.

15. A flat panel display manufactured according to the method of claim 13.