Position detector, position detection method, imprint apparatus, and product manufacturing method

Patent metadata

Field	Value
Publication number	US-10634995-B2
Application number	US-201715583822-A
Country	US
Kind code	B2
Filing date	May 1, 2017
Priority date	May 10, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

A position detector includes a detection unit configured to detect light from a first diffraction grating including a first pattern disposed in a first direction, and light from a second diffraction grating including a second pattern disposed in the first direction, and a control unit configured to obtain a relative position between the first and the second diffraction gratings based on the light detected by the detection unit. The position detector has a third pattern formed in a second direction different from the first direction at edges of the first pattern of the first diffraction grating, the third pattern has a width smaller than a width of the first pattern of the first diffraction grating.

First claim

What is claimed is:

1. A position detector comprising:
a detection unit configured to detect a moire formed by a first light diffracted by a first diffraction grating and a second light diffracted by a second diffraction grating, the first diffraction grating including a first pattern disposed in a first direction, and the second diffraction grating including a second pattern disposed in the first direction; and
a control unit configured to obtain a relative position between the first and the second diffraction gratings based on the moire detected by the detection unit,
wherein the detection unit further detects a third light diffracted by a third pattern formed in a second direction different from the first direction at edges of the first pattern of the first diffraction grating, the third pattern having a width smaller than a width of the first pattern of the first diffraction grating in the first direction.

2. The position detector according to claim 1 , wherein the detection unit further detects a fourth light from a fourth pattern formed in the second direction at edges of the second pattern of the second diffraction grating, the fourth pattern having a width smaller than a width of the second pattern of the second diffraction grating in the first direction.

3. The position detector according to claim 1 , wherein widths of the first and second patterns disposed in the first direction used to obtain the relative position are identical.

4. The position detector according to claim 1 , wherein the width of the third pattern in the first direction is smaller than a half of the width of the first pattern in the first direction.

5. The position detector according to claim 1 , wherein at least one of the first and the second diffraction gratings includes a fourth pattern formed in the second direction.

6. The position detector according to claim 1 , wherein the first pattern is composed of a plurality of segments.

7. The position detector according to claim 1 , further comprising an illumination optical system configured to illuminate the first and the second diffraction gratings with light perpendicular to the first direction and illuminate the first diffraction grating with light parallel to the first direction.

8. The position detector according to claim 1 , wherein an intensity spectrum of the moire formed by the first light and the second light and the third light detected by the detection unit is substantially the same at the edges and the center of the first and second diffraction gratings in the second direction.

Assignees

• Canon Kk

Inventors

• Minoda Ken
• Miyaharu Takafumi

Classifications

• G03F9/7076

  Mark details, e.g. phase grating mark, temporary mark · CPC title

• G05B19/19

  characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path · CPC title

• G03F7/0002 Primary

  Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping · CPC title

• B29L2011/00

  Optical elements, e.g. lenses, prisms · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title