Position detection apparatus and exposure apparatus

• US 7,590,280 B2
• Filed: 08/04/2006
• Issued: 09/15/2009
• Est. Priority Date: 03/09/1999
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tanaka, Hiroshi
• Primary Examiner(s): Chawan; Sheela C
• Application Number:
  US11/498,747
• Publication Number:
  US 20060269122A1
• Time in Patent Office: 1,138 Days
• Field of Search: 382/147, 382/151, 382/181, 382/184, 382/190, 382/199, 382/209, 382/216, 382/218, 382/219, 382/266, 382/287, 250/491.1, 250/492.2, 250/492.22, 250/559.36, 349/95, 349/158, 430/5, 430/296, 356/401
• US Class Current: 382/151
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection
• CPC Class Codes: G03F 9/7092 Signal processing
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/74 involving reference images or patches

Abstract

An exposure apparatus for exposing an object to light. The apparatus includes a camera which captures an image of a mark on the object to obtain image data corresponding to the image, an extraction section which extracts an edge position in the image data obtained by differentiating the image data, a determination section which determines a position of the mark by comparing the extracted edge position with a template, and a control section which changes at least one of a parameter used by the extraction section and a parameter used by the determination section, based on a result of the comparing by the determination section. The object to be exposed is positioned based upon the position of the mark determined by the determination section.

Claims

1. An exposure apparatus for exposing an object to light, said apparatus comprising:

a camera which captures an image of a mark on the object to obtain image data corresponding to the image;

an extraction section which extracts an edge position in the image data obtained by differentiating the image data;

a determination section which determines a position of the mark by comparing the extracted edge position with a template; and

a control section which changes at least one of a parameter used by said extraction section and a parameter used by said determination section, based on a result of the comparing by said determination section,

wherein the object to be exposed is positioned based upon the position of the mark determined by said determination section.

2. An apparatus according to claim 1, wherein the parameter changed by said control section is stored in a memory and used as a base for processing to be executed later.

3. An apparatus according to claim 1, wherein said determination section performs the comparing by obtaining a degree of matching between the edge position and the template.

4. An apparatus according to claim 3, wherein said determination section determines the position of the mark as a center position of the template, of which position is determined based on the degree of matching.

5. An apparatus according to claim 3, wherein said determination section determines the position of the mark based on the degree of matching, and the parameter used by said determination section is a threshold for the degree of matching.

6. An apparatus according to claim 1, wherein said determination section performs the comparing using a correlation method.

7. An apparatus according to claim 1, wherein said extraction section differentiates the image data along each of at least two directions.

8. An apparatus according to claim 1, wherein the template includes a plurality of positions of interest.

9. An apparatus according to claim 1, wherein a parameter used for at least one of a noise removal processing for the image data and a correction of the edge position is changed based on a result of the comparing by said determination section.

10. An apparatus according to claim 1, wherein said camera captures the image under a dark field illumination.

11. An apparatus according to claim 1, wherein said extraction section extracts the edge position based on a differential value of the image data, and the parameter used by said extraction section is a threshold for the differential value.

12. A method of manufacturing a semiconductor device, said method comprising steps of:

capturing, using a camera, an image of a mark on a substrate to be exposed, to obtain image data corresponding to the image;

extracting, using an extraction section, an edge position in the image data obtained by differentiating the image data;

determining, using a determination section, a position of the mark by comparing the extracted edge position with a template;

changing, using a control section, at least one of a parameter used in said extracting step and a parameter used in said determining step, based on a result of the comparing in said determining step;

positioning the substrate based upon the position of the mark determined in said determining step;

exposing the positioned substrate to light, to produce an exposed substrate;

developing the exposed substrate, to produce a developed substrate; and

processing the developed substrate to manufacture the semiconductor device.