The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 07, 1997
Filed:
Jul. 22, 1993
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
An electric field measuring apparatus for causing an optical probe head having an electro-optic member with an electro-optic material to oppose a sample such as a semiconductor integrated circuit device and for optically measuring a voltage of an opposite portion of the sample. The electro-optic material consists of an LiTaO.sub.3 electro-optic crystal or the like, the polarization characteristics of which change depending on the electric-field strength of the sample. The electro-optic member is supported on a guide mechanism to be reciprocally movable within a predetermined stroke range in a direction of the sample. The guide mechanism is reciprocated in the direction of the sample to control the distance between the electro-optic material and the sample. In measurement, light is incident on the electro-optic material whose polarization characteristics change depending on the electric-field strength, and the light intensity of a predetermined polarized component of the light reflected by the electro-optic material is detected, thereby measuring the electric-field strength and voltage of the sample. When if the electro-optic member is brought into contact with the sample, the sample is not damaged due to the stroke set in the guide mechanism. The simple structure of the guide mechanism realizes improvement of operability. The electro-optic member can therefore safety approach the sample to increase the measurement sensitivity.