Inspection device and inspection method

Patent metadata

Field	Value
Publication number	US-10976284-B2
Application number	US-201916731273-A
Country	US
Kind code	B2
Filing date	Dec 31, 2019
Priority date	Dec 3, 2015
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

An inspection apparatus comprises a light output unit configured to output first light having a first wavelength and second light having a second wavelength, a magneto-optical crystal arranged so that a reflection film faces a measurement target, a light detection unit configured to detect the first light and the second light, and a light guide optical system configured to guide the first light and the second light toward the magneto-optical crystal and the measurement target, and guide the first light reflected by the magneto-optical crystal and the second light reflected by the measurement target toward the light detection unit. The light guide optical system comprises an optical path switching element configured to perform switching between optical paths of a plurality of optical elements so that the first light and the second light are selectively incident on the light detection unit.

First claim

The invention claimed is:

1. An inspection apparatus for inspecting a measurement target, the inspection apparatus comprising:
a first light source configured to emit first light having a first wavelength;
a second light source configured to emit second light having a second wavelength different from the first wavelength;
a magneto-optical crystal having a reflection surface configured to reflect the first light, the reflection surface being arranged facing the measurement target;
a first light sensor configured to detect the first light;
a second light sensor configured to detect the second light; and
a light guide optical system comprising a plurality of optical elements and configured to guide the first light and the second light toward the magneto-optical crystal and the measurement target and guide the first light reflected by the magneto-optical crystal toward the first light sensor and guide the second light reflected by the measurement toward the second light sensor,
wherein the light guide optical system comprises an optical path switching element configured to perform switching between optical paths of the plurality of optical elements so that the first light is incident on the first light sensor and the second light is incident on the second light sensor,
wherein the light guide optical system comprises a polarization control element configured to guide one polarized component of the first light to the first light sensor, and
wherein, on a previous stage side of the optical path switching element, an optical path of the first light is independent of an optical path of the second light.

2. The inspection apparatus according to claim 1 , wherein the optical path switching element comprises a dichroic mirror.

3. The inspection apparatus according to claim 1 , wherein the light guide optical system further comprises a polarization control element configured to guide another polarized component of the first light to the first light sensor.

4. The inspection apparatus according to claim 1 , wherein the measurement target is a semiconductor device.

5. The inspection apparatus according to claim 1 , wherein the first wavelength is shorter than the second wavelength.

6. The inspection apparatus according to claim 1 , wherein the magneto-optical crystal reflects the first light and transmits the second light.

7. An inspection method of inspecting a measurement target by using a magneto-optical crystal arranged facing the measurement target, the inspection method comprising the step of:
guiding first light having a first wavelength and second light having a second wavelength different from the first wavelength toward the magneto-optical crystal and the measurement target through a light guide optical system and detecting the first light and the second light reflected by the magneto-optical crystal or the measurement target,
wherein the step comprises the steps of:
outputting the first light from a first light source and detecting the first light in a first light sensor via the light guide optical system;
selectively performing switching between optical paths of the light guide optical system so that the first light is incident on the first light sensor and the second light is incident on the second light sensor; and
outputting the second light from a second light source and detecting the second light in a second light sensor via the light guide optical system,
wherein, on a previous stage side of the optical path switching element, an optical path of the first light is independent of an optical path of the second light.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Nakamura Tomonori

Classifications

• G01R33/0322 Primary

  using the Faraday or Voigt effect · CPC title

• G02B21/0016

  Technical microscopes, e.g. for inspection or measuring in industrial production processes · CPC title

• G02B17/02

  Catoptric systems, e.g. image erecting and reversing system · CPC title

• G01R31/311

  of integrated circuits {(G01R31/31728 takes precedence)} · CPC title

• G02B21/361

  Optical details, e.g. image relay to the camera or image sensor (G02B21/364 takes precedence; illumination details G02B21/06 and subgroups) · CPC title