# US 2014/0152991 A1 · Level Sensor of Exposure Apparatus and Wafer-Leveling Methods Using the Same

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- Number: US 2014/0152991 A1
- Document ID: US20140152991A1
- Status: Published application
- Kind: A1
- Application number: 13/901,652
- Filed: 2013-05-24
- Published: 2014-06-05
- Earliest claimed: 2012-07-24
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Jinseok Heo; Jeongho Yeo
- Web page: https://patentgrep.com/patent/US20140152991A1

## CPC

- G01B 11/24: for measuring contours or curvatures
- G01B 11/26: for measuring angles or tapers; for testing the alignment of axes
- G03F 9/7034: {Leveling}
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)

## Abstract

A level sensor of an exposure apparatus includes a light source that generates light that is illuminated onto a top surface of a wafer, a projection part provided in a path of incident light propagating from the light source to the wafer and having a single first slit, a detection part provided in a path of light reflected from the wafer and having a single second slit, and a detector that detects the reflected light that is incident on the second slit of the detection part.

## Claims

### Claim 1

A level sensor of an exposure apparatus, comprising:
a light source that generates light that is illuminated onto a top surface of a wafer;
a projection part provided in a path of incident light propagating from the light source to the wafer, the projection part having a single first slit;
a detection part provided in a path of reflected light that is reflected from the wafer, the detection part having a single second slit; and
a detector that detects the reflected light that passes through the second slit of the detection part.

### Claim 2 (depends on 1)

The level sensor of claim 1, wherein the detector comprises an imaging device configured to sense the reflected light two-dimensionally.

### Claim 3 (depends on 2)

The level sensor of claim 2, wherein the imaging device comprises a charge-coupled device.

### Claim 4 (depends on 1)

The level sensor of claim 1, wherein the detector is configured to sense a change in intensity of the reflected light.

### Claim 5 (depends on 1)

The level sensor of claim 1, wherein the light source comprises a halogen lamp.

### Claim 6 (depends on 1)

The level sensor of claim 1, wherein the first slit has a width of 4 mm or less and a length of 26 mm or more.

### Claim 7 (depends on 1)

The level sensor of claim 1, wherein the second slit has a width and a length that are equal to or greater than a width and a length of the first slit, respectively.

### Claim 8 (depends on 1)

The level sensor of claim 1, wherein the detector is in contact with a first surface of the detection part opposite to a second surface of the detection part onto which the reflected light is incident.

### Claim at position 9

-14. (canceled)