INSPECTION APPARATUS AND INSPECTION METHOD USING ELECTROMAGNETIC WAVE

• US 20090056455A1
• Filed: 08/21/2008
• Published: 03/05/2009
• Est. Priority Date: 08/31/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ouchi, Toshihiko
• Granted Patent: US 7,963,168 B2
• Time in Patent Office: Days
• US Class Current: 73/643
• CPC Class Codes: G01N 2021/845 Objects on a conveyor
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 21/9508 Capsules; Tablets

Abstract

The present invention is to provide inspection apparatus and method of being able to acquire electromagnetic wave response information of an inspection object at high speed as average information using an electromagnetic wave. An inspection apparatus using an electromagnetic wave 2 includes an electromagnetic wave generation and irradiation unit 9 which generates an electromagnetic wave and irradiates the electromagnetic wave on an inspection object 11, and an electromagnetic wave detection unit 10 having a plurality of detection units. The plurality of detection units is arranged so as to detect the electromagnetic wave which is irradiated by the electromagnetic wave generation and irradiation unit and is transmitted or reflected with interacting with different sites of the inspection object 11, and is constructed so as to detect the electromagnetic wave from the different sites in different detection time or detection frequencies respectively. The inspection apparatus acquires electromagnetic wave response information on the inspection object 11 based on detection signals from the plurality of detection units.

Claims

1. An inspection apparatus for performing an inspection using a terahertz wave, comprising:

an electromagnetic wave generation and irradiation unit which generates a terahertz wave and irradiates the terahertz wave on an inspection object; and

an electromagnetic wave detection unit having a plurality of detection units, wherein the plurality of detection units is arranged so as to detect the terahertz wave which is irradiated by the electromagnetic wave generation and irradiation unit and is transmitted or reflected with interacting with different sites of an inspection object, and is constructed so as to detect the terahertz wave from the different sites in different detection time or detection frequencies respectively to acquire terahertz wave response information from the inspection object based on detection signals from the plurality of detection units.

2. The inspection apparatus according to claim 1, wherein the terahertz wave includes a plurality of frequencies in a frequency domain of 30 GHz to 30 THz and the plurality of frequencies is irradiated on the different sites of an inspection object respectively;

and

wherein respective transmission intensity ratios of the plurality of frequencies are acquired.

3. The inspection apparatus according to claim 1, wherein the terahertz wave is a pulse which includes a portion of frequencies in a frequency domain of 30 GHz to 30 THz and the terahertz wave is irradiated on the different sites of an inspection object respectively;

and

wherein average terahertz wave spectral information of an inspection object is acquired based on the detection signals of the transmitted or reflected terahertz wave which is detected by the plurality of detection units.

4. The inspection apparatus according to claim 1, further comprising:

a plurality of mirrors; and

a laser for irradiating light on the electromagnetic wave detection unit via the plurality of mirrors and on the electromagnetic wave generation and irradiation unit, wherein average terahertz wave spectral information of an inspection object is acquired based on the detection signals of the transmitted or reflected terahertz wave which is detected by the plurality of detection units which are irradiated by the light reflected by the plurality of mirrors.

5. The inspection apparatus according to claim 1, further comprising:

a plurality of fibers which differ in length; and

a fiber laser for irradiating light on the electromagnetic wave detection unit via the plurality of fibers and on the electromagnetic wave generation and irradiation unit, wherein average terahertz wave spectral information of an inspection object is acquired based on the detection signals of the transmitted or reflected terahertz wave which are detected by the plurality of detection units which is irradiated by light through the plurality of fibers.

6. An inspection method for performing an inspection using a terahertz wave, comprising:

a step of generating a terahertz wave and irradiating the terahertz wave on different sites of an inspection object;

a step of detecting the terahertz wave, which is transmitted or reflected with interacting with different sites of an inspection object, by a plurality of detection units in different detection time or detection frequencies, respectively; and

a step of acquiring terahertz wave response information from the inspection object based on detection signals from the plurality of detection units.

7. The inspection method according to claim 6, wherein the inspection object is an object constructed by a plurality of specimens of the same kind being arranged, or by a homogeneous specimen.

8. The inspection method according to claim 6, wherein the inspection object moves, and different sites of the inspection object change sequentially as the inspection object moves.

9. The inspection method according to claim 6, further comprising:

a step of screening a specimen when the acquired terahertz wave response information is out of a reference value range which a homogeneous specimen or specimens of the same kind should fulfill.

10. The inspection method according to claim 6, further comprising:

a step of performing feedback control of manufacturing conditions of a production apparatus of the specimen so as to be adjusted in the reference value range when the acquired terahertz wave response information is out of a reference value range which a homogeneous specimen or specimens of the same kind should fulfill.

11. An inspection apparatus for performing an inspection using a terahertz wave, comprising:

a plurality of generation units for generating a terahertz wave; and

a detection unit for detecting the terahertz wave which is generated by the generation unit and is transmitted or reflected by the inspection object, wherein the plurality of detection units is arranged so as to detect the transmitted or reflected terahertz wave with different delay time respectively, and a time waveform of the transmitted or reflected terahertz wave is acquired using the information regarding the terahertz wave which the plurality of detection units detect.

12. The inspection apparatus according to claim 11, wherein the plurality of generation units and the plurality of detection units are a plurality of photoconductive elements arranged in the shape of a one dimensional array, and a laser beam in a rectangular shape is irradiated on the plurality of photoconductive elements simultaneously, and is condensed in a line.