Electrical characteristics of leakage issues caused by defective Ni salicide

Abstract

Ni diffusion in sub-lOO nm devices can adversely affect electrical performance, and contribute greatly to yield loss. Despite the tremendous advantages of Ni salicide technology over Ti or Co, there are problems associated with the intrinsic properties of NiSi. Ni spiking into Si substrate or conductive bridges between silicide on the gate electrodes and that on the source/drain terminals can occur. These effects can be induced or enhanced by stringent layout, stress or process conditions. Its impact can be evident from electrical failure analysis such as nanoprobing and C-AFM, that are useful in identifying the cause of failure.

Applications of C-AFM analysis techniques at advanced IC on SRAM soft failure

“…C-AFM characteristic was carried out using a conductive probe, a doped diamond coated probe tip, to scan across the sample surface, a constant DC bias was applied between the contact and the sample substrate to obtain the current contrast image and the I-V characteristic. [3] We can represent PWELL/N-plus/NLDD into a P/N junction diagram as show in Fig.7. Under normal condition, P/N-junction will turn on first due to lower Vth.…”