Title:
METHOD FOR INSPECTING FOREIGN ARTICLE BY HETERODYNE POLARIZATION AND APPARATUS CARRYING OUT THE METHOD
Document Type and Number:
Japanese Patent JP3795657
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To enhance utilization efficiency for light and obtain information related to qualities of foreign articles.
SOLUTION: A light beam from a light source 1L is split half by a beam splitter 3, thereby obtaining a probing light of a single linearly polarized light and a reference light of a linearly polarized light having the same direction of polarization. At least one of the probing light and the reference light is shifted in frequency by a frequency shifter 4 driven by a modulation signal. The probing light is projected to a body 21 to be inspected, and a reflecting light and the reference light are brought into a photoelectric converter 12 and subjected to heterodyne detection, whereby a beat signal is obtained. A parameter indicating a quality of a foreign article is extracted by a parameter extraction part 16 from the beat signal and a reference signal as the modulation signal. The extracted parameter is analyzed by a detected data-analyzing part 17. The foreign article is detected in this manner.
Inventors:
Yoshio Haruo
Application Number:
JP1577298A
Publication Date:
July 12, 2006
Filing Date:
January 28, 1998
Export Citation:
Assignee:
Advantest Corporation
International Classes:
G01N21/21; G01N21/88; G01N21/93; G01N21/94; G01N21/956; H01L21/66; (IPC1-7): G01N21/21; G01N21/88; H01L21/66
Domestic Patent References:
| JP8278202A | ||||
| JP8313600A | ||||
| JP6317534A | ||||
| JP4031745A | ||||
| JP6213821A | ||||
| JP7243965A |
Attorney, Agent or Firm:
Naoki Nakao
Yukio Nakamura
Taku Kusano
Minoru Inagaki
Yukio Nakamura
Taku Kusano
Minoru Inagaki