Inspection apparatus and inspection method

Patent metadata

Field	Value
Publication number	US-9404874-B2
Application number	US-201514667648-A
Country	US
Kind code	B2
Filing date	Mar 24, 2015
Priority date	Mar 25, 2014
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

An inspection apparatus according to an aspect of the present invention inspects a solar cell that is of a photo device. The inspection apparatus includes: an irradiation part that irradiates the solar cell with pulse light emitted from a femtosecond laser that is of a light source; an electromagnetic wave detection part that detects an electromagnetic wave pulse emitted from the solar cell in response to the irradiation of the solar cell with the pulse light; and a PL light detection part that detects photoluminescence light generated in the solar cell in response to the irradiation of the solar cell with the pulse light.

First claim

What is claimed is:

1. An inspection apparatus that inspects an inspection object including a semiconductor device or a photo device, the inspection apparatus comprising:
an irradiation part that irradiates said inspection object with pulse light emitted from a femtosecond laser;
an electromagnetic wave detection part that detects an electromagnetic wave emitted from said inspection object in response to the irradiation of said inspection object with said pulse light; and
a PL light detection part that detects photoluminescence light emitted from said inspection object in response to the irradiation of said inspection object with said pulse light generating said electromagnetic wave from said inspection object,
said electromagnetic wave detection part comprising:
a detector that detects an electric field intensity of said electromagnetic wave by receiving probe light emitted from said femtosecond laser; and
a delay part that that delays a time said probe light is incident to said detector relative to a time said electromagnetic wave is incident to said detector,

said inspection apparatus further comprising a time waveform restoration part that restores a time waveform of said electromagnetic wave based on an electric field intensity of said electromagnetic wave detected by operating a delay part.

2. The inspection apparatus according to claim 1 , wherein said pulse light is light that can reach a portion deeper than a depletion layer of said inspection object.

3. The inspection apparatus according to claim 1 , wherein said pulse light is light that is absorbed by a depletion layer in said inspection object.

4. The inspection apparatus according to claim 1 , further comprising a scanning mechanism that scans an inspection object area in said inspection object with said pulse light.

5. The inspection apparatus according to claim 4 , further comprising an electromagnetic wave intensity distribution image generation part that generates an electromagnetic wave intensity distribution image indicating an intensity distribution of said electromagnetic wave generated in said inspection object area.

6. The inspection apparatus according to claim 4 further comprising a PL light intensity distribution image generation part that generates a PL light intensity distribution image indicating an intensity distribution of said photoluminescence light generated in said inspection object area.

7. The inspection apparatus according to claim 6 , further comprising:
an electromagnetic wave intensity distribution image generation part that generates an electromagnetic wave intensity distribution image indicating an intensity distribution of said electromagnetic wave generated in said inspection object area; and
an image synthesis part that synthesizes said PL light intensity distribution image and said electromagnetic wave intensity distribution.

8. The inspection apparatus according to claim 1 , further comprising an inspection position setting part that sets a position where said irradiation part irradiates said inspection object with said pulse light in order to restore said time waveform.

9. The inspection apparatus according to claim 4 , further comprising a determination part that determines whether an intensity of said photoluminescence light detected by said PL light detection part satisfies a predetermined reference value, wherein
said scanning mechanism scans an area where said reference value is not satisfied with said pulse light, and
said electromagnetic wave detection part detects an electromagnetic wave generated by the scan.

10. An inspection method for inspecting an inspection object including a semiconductor device or a photo device, the inspection method comprising the steps of:
(a) irradiating said inspection object with pulse light emitted from a femtosecond laser;
(b) detecting an electromagnetic wave emitted from said inspection object in response to the irradiation of said inspection object with said pulse light; and
(c) detecting photoluminescence light emitted from said inspection object in response to the irradiation of said inspection object with said pulse light generating said electromagnetic wave from said inspection object, wherein
said step (b) includes:
(b-1) detecting an electric field intensity of said electromagnetic wave by a detector by receiving probe light emitted from said femtosecond laser; and
(b-2) delaying a time said probe light is incident to said detector relative to a time said electromagnetic wave is incident to said detector,

said inspection method further comprising the step of restoring a time waveform of said electromagnetic wave based on an electric field intensity of said electromagnetic wave detected by said step (b-2).

11. The inspection method according to claim 10 , wherein said step (a) includes
(a-1) a step of scanning an inspection object area of said inspection object with said pulse light.

12. An inspection apparatus that inspects an inspection object including a semiconductor device or a photo device, the inspection apparatus comprising:
an irradiation part that irradiates said inspection object with pulse light emitted from a light source;
an electromagnetic wave detection part that detects an electromagnetic wave emitted from said inspection object in response to the irradiation of said inspection object with said pulse light;
a PL light detection part that detects photoluminescence light emitted from said inspection object in response to the irradiation of said inspection object with said pulse light generating said electromagnetic wave from said inspection object;
a scanning mechanism that scans an inspection object area in said inspection object with said pulse light; and
a determination part that determines whether an intensity of said photoluminescence light detected by said PL light detection part satisfies a predetermined reference value, wherein
said scanning mechanism scans an area where said reference value is not satisfied with said pulse light, and
said electromagnetic wave detection part detects an electromagnetic wave generated by the scan.

Assignees

• Screen Holdings Co Ltd
• Univ Osaka
• Screen Holdings Co Ltd

Inventors

• Nakanishi Hidetoshi
• Ito Akira
• Kawayama Iwao
• Tonouchi Masayoshi

Classifications

• G01N2201/0697

  Pulsed lasers · CPC title

• G01N21/6489

  Photoluminescence of semiconductors · CPC title

• G01N2201/06113

  Coherent sources; lasers · CPC title

• G01N21/9501 Primary

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01N2201/10

  Scanning · CPC title