Progress in photoemission sampling

The basic principles, fundamental limits, and recent results of the novel photoemission probing method are reviewed. The possible range of applications as a contactless diagnostic method for integrated circuits in the real-time and sampling modes of photoemission probing is discussed on the basis of theoretical and experimental studies. In photoemission sampling, electron emission is induced in a sample by an incident light beam (in most cases a laser beam), and the photoemitted electrons are then accelerated towards a reference or retarding field electrode. If the reference electrode is at the same potential as the point of electron emission on the VLSI circuit, all photoemitted electrons can pass the reference electrode and are guided towards an electron detector