Patent ID: 6707055
Filing Date: 2004-03-16
Classification: G01N

Abstract:
An apparatus for detecting defects in a layer of dielectric material, said defects characterized by an absence of said dielectric material, where the absence of dielectric material provides a continuous path across the layer, said layer having a supported surface and an unsupported surface, said apparatus comprising:a first electrode, said first electrode having a layer supporting surface in contact with at least one point of the supported surface of the layer; and at least one second electrode oppositely spaced apart from the layer supporting surface of said first electrode and oppositely spaced apart from, the unsupported surface of said layer, said layer being disposed between the layer supporting surface of said first electrode and said second electrode; and means for applying a voltage across said first and second electrodes, said voltage being at least equal to the breakdown voltage corresponding to said spacing between the first and second electrodes in the absence of the layer of dielectric material; and means for detecting the presence and characteristics of defects, said means being responsive to variations of a flow of electrical current from said first electrode to the at least one second electrode.