Leakage current study and relevant defect localization in integrated circuit failure analysis

• A method is elaborated to study the leakage currents and locate relevant defects.
• Different leakage currents stimulated different photon emission spots.
• Two typical defects stimulating leakage currents in IC were studied.
• 4 complicated functional failure cases have been studied according to this method.

The purpose of integrated circuit (IC) failure analysis (FA) is to find and to explain failure root cause and mechanism, which helps IC designer and manufacturer to improve design and process. Leakage current presence within circuit is the main failure root cause among the FA cases, although the leakage currents within different circuits can stimulate a variety of IC failure modes. It is significant to study the leakage currents within ICs and to localize relevant defects quickly and accurately by the combination of some complementary FA techniques. However, it is difficult to identify the original leakage current from the consequential leakage currents and to locate the relevant defect.In this paper, we explain the shape and location of a photon emission spot induced by an original leakage current is different from the one induced by a consequential leakage current. In a general case, and not only in this photon emission spot case, a method is elaborated to identify the original leakage current from the consequential leakage currents and to exactly locate the relevant defect by the combination of some complementary FA techniques. Some other functional failure cases will be studied to demonstrate adaptation and interest of this general method.