Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
TEST DEVICE
Document Type and Number:
WIPO Patent Application WO/2013/018878
Kind Code:
A1
Abstract:
Light scattered by flaws on a wafer is extremely weak, and PMT and MPPC are detection methods for measuring the weak light at high speed and high sensitivity. The detection method has a function for photoelectrically converting the weak light and exponentially increasing the number of electrons; however, since the quantum efficiency of photoelectric conversion is low; i.e., 50% or less, a problem is presented in regard to losing the signal light and reducing the S/N ratio. The present invention addresses light amplification for directly amplifying light before photoelectric conversion. Light amplification is a method in which a signal light and light from an excitation light source are introduced into a rare-earth-doped fiber, and the signal light is amplified upon induced emission. The present invention is characterized in that this light amplification is used. The present invention is further characterized in that the amplification factor changes due to a variety of conditions.

Inventors:
OKU MIZUKI (JP)
SHIMURA KEI (JP)
Application Number:
PCT/JP2012/069787
Publication Date:
February 07, 2013
Filing Date:
August 03, 2012
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HITACHI HIGH TECH CORP (JP)
OKU MIZUKI (JP)
SHIMURA KEI (JP)
International Classes:
G01N21/956
Foreign References:
JP2008096430A2008-04-24
JP2009068903A2009-04-02
JP2009115753A2009-05-28
JP2010099095A2010-05-06
JP2001108638A2001-04-20
JPH05261106A1993-10-12
JP2001085482A2001-03-30
Attorney, Agent or Firm:
INOUE Manabu et al. (JP)
Manabu Inoue (JP)
Download PDF:
Claims: