Lithographic apparatus, method for calibrating and device manufacturing method

• US 20070145306A1
• Filed: 02/12/2007
• Published: 06/28/2007
• Est. Priority Date: 05/28/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Bleeker, Arno, Baselmans, Johannes
• Granted Patent: US 7,459,710 B2
• Time in Patent Office: Days
• US Class Current: 250/548
• 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 7/70516 Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors
• CPC Class Codes: G03F 7/70591 Testing optical components

Abstract

To calibrate a lithographic apparatus having a programmable patterning means, a sensor, such as a CCD, CMOS sensor or photo-diode array, having detector elements larger than the size of a spot corresponding to a single pixel of the programmable patterning means is used. Pixels are selectively activated singly or in groups.

Claims

1. A method of calibrating a lithographic apparatus, comprising:

(a) patterning a projection beam using an array of individually controllable elements;

(b) directing the patterned projection beam towards a substrate table using a projection system;

(c) locating a detector having a plurality of detector elements in a path of the patterned projection beam, each of the detector elements being larger than a spot corresponding to a single element of the array of individually controllable elements;

(d) selectively activating the detector elements;

(e) measuring an amount of radiation received on respective ones of the detector elements from the patterned projection beam; and

(f) calibrating the lithographic projection apparatus based on the measuring step (e).

2. The method of claim 1, wherein step (d) comprises activating the elements in the array of individually controllable elements during a measurement interval in step (e) so that only one of the elements of the array of individually controllable elements corresponding to a respective one of the detector elements is activated.

3. The method of claim 2, wherein steps (d) and (e) are repeated with a different one of the elements in the array of individually controllable elements corresponding to a respective one of the detector elements being activated.

4. The method of claim 3, wherein the detector is moved relative to the patterned projection beam between repeats of steps (d) and (e).

5. The method of claim 1, wherein step (d) comprises activating individual ones of the elements in the array of individually controllable elements so that during a first measurement interval a first set of the elements in the array of individually controllable elements corresponding to a respective one of the detector elements is activated.

6. The method of claim 5, wherein steps (d) and (e) are repeated with a different set of the elements in the array of individually controllable elements corresponding to a respective one of the detector elements being activated.

7. The method of claim 6, wherein the detector is moved relative to the patterned projection beam between repeats of steps (d) and (e).

8. The method of claim 1, further comprising:

(g) projecting the patterned beam of radiation onto a target portion of the substrate.