Contactless gigahertz testing

Circuit internal test techniques working in a contactless manner are necessary for failure analysis and design verification. This paper gives an overview of the most important contactless test techniques. For the mechanical sensors, the electron beam test, the electro-optic sampling, and the electric scanning force microscopy, the state-of-the-art in respect to gigahertz testing, will be discussed. Some measurement examples will be given. In more detail a new technique, the electric scanning force microscopy, will be discussed