Method for determining the presence of thin insulating films

摘要

There is provided a method for determining the presence of an insulating film on the surface of an electrically conductive material. In this method, an electrically conductive probe is brought into contact with the surface of a specimen, and a voltage is applied between the probe and the surface of the specimen. A tunneling current which flows through the probe is detected and amplified, while controlling the distance between the probe and the surface of the specimen to ensure a substantially constant tunneling current.