Contactless gigahertz testing

Circuit internal test techniques working in a contactlessmanner are necessary for failure analysis and designverification. This paper gives an overview of the mostimportant contactless test techniques. For the mechanicalsensors, the electron beam test, the electro-optic sampling,and the electric scanning force microscopy the state-of-the-artin respect to gigahertz testing will be discussed. Somemeasurement examples will be given. In more detail a newtechnique, the electric scanning force microscopy, will bediscussed.