DEFECT DETECTION DEVICE AND DEFECT OBSERVATION DEVICE

• US 20180088469A1
• Filed: 09/25/2017
• Published: 03/29/2018
• Est. Priority Date: 09/26/2016
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: OTANI, Yuko, AOKI, Kazuo, HONDA, Toshifumi, KANZAKI, Nobuhiko
• Granted Patent: US 10,642,164 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/95623 using a spatial filtering method per se G02B
• CPC Class Codes: G03F 7/70191 Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like
• CPC Class Codes: G03F 7/702 Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems
• CPC Class Codes: G03F 7/7065 Defects, e.g. optical inspection of patterned layer for defects

Abstract

Provided is a defect detection device including an illumination unit including a condenser lens and a plurality of light beam synthesis units, and a detection unit detecting scattered light generated on a sample by the illumination unit. The condenser lens condenses a plurality of light beams, emitted onto the sample and having substantially the same wavelength and substantially the same polarization, on the sample. The plurality of light beam synthesis units bring the plurality of light beams close to each other and make the light beams have light paths parallel to the optical axis of the condenser lens.

Claims

1. A defect detection device comprising:

an illumination unit that includes a condenser lens and a plurality of light beam synthesis units, the condenser lens condensing a plurality of light beams, emitted onto a sample and having substantially the same wavelength and substantially the same polarization, on the sample, and the plurality of light beam synthesis units bringing the plurality of light beams into close to each other and making the light beams have light paths parallel to an optical axis of the condenser lens; and

a detection unit that detects scattered light generated on the sample by the illumination unit.

2. The defect detection device according to claim 1,

wherein the detection unit includes a filter, having dependence on a wavelength and polarized light, on a pupil surface.

3. The defect detection device according to claim 1,

wherein the plurality of light beams are emitted from a plurality of light sources.

4. The defect detection device according to claim 1,

wherein the plurality of light beams are light beams obtained by dividing a light beam emitted from a single light source.

5. The defect detection device according to claim 3,

wherein each of the plurality of light beam synthesis units includes a polarized beam splitter and a combination wavelength plate.

6. The defect detection device according to claim 3,

wherein a polarizer or a polarized beam splitter, which is set to have an extinction ratio equal to or higher than 100:

1 of polarization directions of the plurality of light beams, is disposed between the plurality of light beam synthesis units and the condenser lens.

7. The defect detection device according to claim 5,

wherein the plurality of light sources are mounted in a direction in which light beams in the same polarization direction are emitted, and polarization directions of light beams emitted from some of the plurality of light sources are rotated by 90 degrees by a ½

wavelength plate.

8. The defect detection device according to claim 3,

wherein the plurality of light beam synthesis units are mirrors.

9. The defect detection device according to claim 3,

wherein wavelengths of some of the plurality of light beams are shifted by an AO frequency shifter, and the plurality of light beam synthesis units are dichroic mirrors.

10. The defect detection device according to claim 3,

wherein the plurality of light beams are axisymmetrically incident on the optical axis of the condenser lens.

11. The defect detection device according to claim 4,

wherein the single light source is a light source that emits a light beam of linearly polarized light, and a division unit dividing the light beam of the linearly polarized light is a half mirror.

12. The defect detection device according to claim 4,

wherein the single light source is a light source that emits a light beam of linearly polarized light, and a division unit dividing the light beam of the linearly polarized light includes a ¼

wavelength plate and a polarized beam splitter.

13. The defect detection device according to claim 1,

wherein a difference in wavelength between the plurality of light beams is within ±

1% of an average wavelength at most, and a range between polarization axes of the plurality of light beams is within ±

10 degrees.

14. The defect detection device according to claim 1,

wherein some of the plurality of light beams have axes different from the optical axis of the condenser lens.

15. A defect observation device comprising:

the defect detection device according to claim 1; and

a control unit that acquires an image based on scattered light detected by the detection unit of the defect detection device and calculates coordinates of a defect on the basis of the acquired image,

wherein the illumination unit of the defect detection device is disposed outside a pupil of the detection unit.