The scanning electron microscope (SEM) based nanoprobing technique has established itself as an indispensable failure analysis (FA) technique as technology nodes continue to shrink according to Moore's Law. Although it has its share of disadvantages, SEM-based nanoprobing is often preferred because of its advantages over other FA techniques such as focused ion beam in fault isolation. This paper presents the effectiveness of the nanoprobing technique in isolating nanoscale defects in three different cases in sub-100 nm devices: soft-fail defect caused by asymmetrical nickel silicide (NiSi) formation, hard-fail defect caused by abnormal NiSi formation leading to contact-poly short, and isolation of resistive contact in a large electrical test structure. Results suggest that the SEM based nanoprobing technique is particularly useful in identifying causes of soft-fails and plays a very important role in investigating the cause of hard-fails and improving device yield.

Electrical characterizations were needed to identify the root cause of leakage issues in IC devices. The methodology required was dependent on the failure mode obtained during testing and global or nano-scale isolations had to be implemented accordingly. As such, challenges encountered in sample preparation or due to detection methodology choices for every isolation technique have to be addressed in order to localize the defective sites.

As electronic devices shrink further in the nanometer regime, electrical characterization using nanoprobing has become increasingly important. Focused ion beam (FIB) is one useful technique that can be used to create markings for ease of defective site identification during nanoprobing. This paper investigates the impact of FIB exposure on the electrical parameters of the pull-up (PU), pull-down (PD) and pass-gate (PG) transistors of 6-Transistor Static Random Access Memory (6T SRAM) cells.