A practical sample preparation procedure for electron beam (EB) testing using reactive ion etching (RIE) has been developed. By highly accurate anisotropic dry etching, metal wires below dielectric layers can be exposed while successfully maintaining the electrical performance of the LSI. Applying this technique to actual EB tester analysis on specimens with multi-layer metal lines, clear voltage contrast images can be obtained. This preparation procedure greatly reduces the difficulties of acquiring EB contrast images and enables effective failure analysis with fast TAT.

Liquid crystal method is one of the techniques for failure analysis. This technique is well known way to identify a failure point on a silicon integrated circuit. However, the tendency of LSI devices in recent years towards smaller feature size, higher density, lower electric power and larger chip size has created a demand for improvement of this technique towards higher accuracy and increased reliability of failure point localization. In this case, we developed a new technique for applying the liquid crystal method. With this technique, we improved four aspects of the analysis: *Automatjc adjustment of the temperature towards the transference point of the liquid crystal by image processing *Automatjc display of the "hot spot" by image processing *Automatic oscillation of the applied voltage for enhanced visibility of the current leakage point *Mjnute control of the temperature from the reverse side of the package using a Peltier element As a result of this improvement, we could realize improved accuracy for the liquid crystal analysis and reliability of failure point localization. This thesis reports how this technique can be established as a working technique for routine failure analysis, with a practical detection sensitivity of about 1.tW.This method should be called LCIP (Liquid Crystal with Image Processing method).