Apparatus and method for measuring width of micro gap

Abstract

An apparatus and method for measuring a width of a micro gap of a non-conductive material of a sample which is formed between two conductive materials thereof, includes a conductive probe having a sharpened front end, a cantilever having the probe, a sample confronting the probe, a driving device for relatively moving the sample with respect to the probe in three directions of XYZ, and bias power source for applying a voltage between the probe and the sample, an electric current detecting device for detecting a contact current running between the probe and the sample, a micro displacement detecting part which detects an amount of deflection of the cantilever when the sample and the probe are in touch with each other, a servo part which feeds back the amount of the deflection of the cantilever detected by the micro displacement detecting part to the driving device thereby to control to change a position of the sample in the Z-direction of the probe so as to make the amount of the deflection of the cantilever constant, and a measuring device for scanning the probe on the sample in a widthwise direction of the gap of the sample by the driving device, and at the same time sampling outputs of the detecting device thereby to measure the width of the gap in the widthwise direction.