Seminar title: Application of Micro-magnetic Probe for Power Device Diagnosis

Speaker: Kunihiro Asada, professor and director of the VLSI Design and Education Center, University of Tokyo

Seminar abstract:

VDEC is developing a micro-magnetic probe composed of a small coil and a low noise amplifier integrated on a chip. Main purpose of the probe is detection of a weak magnetic field generated by semiconductor devices with a high special resolution. Many types of electronic failures of semiconductor devices are associated with abnormalities of current flow in the devices, which generate different magnetic fields to be differentiated from normal operations. Identification of failure location is the first step of analyzing causes of failures. The magnetic probe is one of the best methods for this purpose. Today, recent results on two applications of the magnetic probe will be presented.

The first example is detection of gate leak current of power devices; IGBT. The location of the leakage has been successfully detected with a good agreement of a microscopic device analysis, which was done after physically removing gate electrodes.

The second example is an analysis of power network integrity of LSI. By comparing a normal chip with an intentionally fabricated abnormal one of missing via in power network, the magnetic probe has successfully detected subtle differences in magnetic fields, which has been again translated to an abnormal power current map analytically.

Both the above examples show that the micro-magnetic probe will be utilized for improving device reliability and fabrication technologies.

Speaker biosketch:

Kunihiro Asada received the B.S., M.S., and Ph.D. from the University of Tokyo in 1975, 1977, and 1980, respectively. In 1980 he joined the Faculty of Engineering, University of Tokyo. From 1985 to 1986 he stayed at Edinburgh University as a visiting scholar. From 1990 to 1992 he served as the Editor of IEICE Transactions on Electronics. In 1996 he established VDEC in University of Tokyo. He served as the Chair of IEEE/SSCS Japan Chapter in 2001-2002 and the Chair of IEEE Japan Chapter Operation Committee in 2007-2008. He is currently professor and director of VDEC. His research interest is design and analysis of integrated systems and devices. He is a member of IEEE, IEICE, and IEEJ.