Patent ID: 6452378
Filing Date: 2002-09-17
Classification: G01R

Abstract:
An electro-optical sampling probe for testing IC wafers comprising:an electro-optic element to contact the wiring on one surface of an IC wafer and having optical properties which change due to an electric field applied through the wiring to act on said electro-optic element; an electro-optic sampling optical system module, which comprises therein polarization beam splitters, half wave plates, and photodiodes, for converting a laser beam into electric signals, separated after a laser beam externally generated has been propagated through said electro-optic element and reflected at a surface of said electro-optic element facing said IC wafer wiring; a first probe body for covering a light path output from said electro-optic sampling optical system module; a first detachable portion for attaching and detaching said electro-optic sampling optical system module to said first probe body; excitation optical system modules for irradiating a light to another surface of the IC wafer in a condensed state for excitation of the IC wafer; a second probe body for covering a light path output from said excitation optical system modules; and second detachable portions, having a form identical with said first detachable portion, for attaching and detaching said excitation optical system modules to said second probe body; wherein the excitation light beam from each of said excitation optical system modules, is condensed by the objective lens for condensing a respective one of said excitation light beams on the IC wafer, and at least one of said excitation optical system modules has a light axis which:differs from that of the other of said excitation optical system modules, so that the excitation light beams are irradiated on at least two different light receiving portions disposed on the IC wafer.