Failure analysis method by using different wavelengths lasers and its application

We succeeded in an accurate detection for failure locations on a silicon se miconductor device (thereafter called "IC") by applying the failure analysi s method in which two kinds of laser beams having different wavelengths are simultaneously irradiated on a surface of IC. Short wavelength laser beam (lambda=1083 nm) causes potential changes in an internal circuit of IC due to generating many electron-hole pairs in the semiconductor. On the other h and, long wavelength laser beam (lambda=1360 nm) causes an easy operation o f parasitic bipolar elements due to increasing temperature of IC by irradia tion heat. By combining these effects of two laser beams, the accurate dete ction of latch-up locations on internal circuits of IC (has been recognized to be difficult up to now) has come possible. (C) 1999 Elsevier Science Lt d. All rights reserved.