H. S. Lin, M. S. Wu, UMC, Hsin-Chu City, Taiwan

Summary: The use of the scanning probe microscope (SPM) such as conductive atomic force microscope (C-AFM) has been widely reported for failure analysis of nano-meter scale science and technology [1-6]. A beam bounce technique is usually used to enable the probe head to measure extremely small movements of the cantilever as it is moved across the surface of the sample. However, the laser beam used for the beam bounce also gives rise to the photoelectric effect while we are measuring electrical characteristics of a device such as a pn junction. In this paper, the photocurrent for a 90nm node device caused by photon illumination was quantitatively evaluated. In addition, this paper also present an example of an application of C-AFM as a tool for failure analysis of trap defects by taking advantage of the photoelectric effect.