Lithographic Apparatus and Device Manufacturing Method

• US 20090051891A1
• Filed: 10/30/2008
• Published: 02/26/2009
• Est. Priority Date: 12/27/2004
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: De Smit, Joannes Theodoor, BIJNEN, Franciscus Godefridus Casper
• Granted Patent: US 8,169,593 B2
• Time in Patent Office: Days
• US Class Current: 355/68
• 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 7/70791 Large workpieces, e.g. glass substrates for flat panel displays or solar panels
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment

Abstract

A system and method use a substrate with a pattern of individual, indiscrete alignment marks, i.e., the marks are separate and distinct from each other, and each mark is not divided into component parts. The pattern of marks is distributed over an area of the substrate, and the method also comprises the steps of providing a beam of radiation using an illumination system and an array of individually controllable elements to impart the beam with a pattern in its cross-section, providing a projection system to project the patterned beam onto the substrate, and providing a movement system to effect relative movement between the substrate and the projection system. A detection system, able to detect the alignment marks individually, is also provided, and the method includes using the detection system to detect the marks to determine a relative position of the substrate to the projection system, using the movement system to position the substrate relative to the projection system, and using the projection system to project the patterned beam of radiation onto a target portion of the substrate. The pattern comprises one or more rows of simple alignment marks, such as spots and short linear marks.

Claims

1. A lithographic apparatus, comprising:

an illumination system that supplies a beam of radiation;

an array of individually controllable elements that pattern the beam;

a projection system that projects the patterned beam onto a target portion of a substrate;

a movement system that causes relative movement between the substrate and the projection system; and

a detection system arranged to detect individual, indiscrete alignment marks distributed in a pattern over an area of the substrate so as to determine a relative position of the substrate to the projection system.

2. The apparatus of claim 1, wherein the detection system detects rows of the alignment marks on the substrate.

3. The apparatus of claim 1, wherein the detection system detects rows of the alignment marks spaced apart along edge portions of the substrate.

4. The apparatus of claim 1, wherein the detection system detects rows of the alignment marks at a plurality of positions across the substrate.

5. The apparatus of claim 1, wherein the detection system comprises at least one camera.

6. The apparatus of claim 1, wherein the detection system comprises:

an array of lenses; and

at least one detector to detect radiation reflected from the substrate through the array of lenses.

7. The apparatus of claim 1, wherein:

the projection system comprises a lens array arranged to focus the patterned beam onto the target surface of the substrate; and

the detection system comprises at least one detector arranged to detect radiation reflected from the substrate, through the array of lenses.

8. The apparatus of claim 1, further comprising:

a controller arranged to control the array of individually controllable elements,

wherein the detection system provides a signal to the controller, the signal being indicative of a position of the substrate relative to the projection system, the controller being arranged to control the elements according to the signal from the detection system.

9. The apparatus of claim 1, further comprising:

a controller arranged to control the movement system,

wherein the detection system is provides a signal to the controller, the signal being indicative of a position of the substrate relative to the projection system, the controller being arranged to control the movement system according to the signal from the detection system.