Impact of TDDB in MG/HK devices on circuit functionality in advanced CMOS technologies

The impact of time-dependent dielectric breakdown (TDDB) in metal gate (MG) / high-k (HK) devices on CMOS circuit functionality is examined using a novel fast PCI card based characterization setup. Detailed information on the role of the driver resistance on circuit failure is provided. By comparing breakdown in circuits to TDDB characteristics in discrete devices, it is shown that soft breakdown in the cross-coupled inverter circuit is well-correlated with soft breakdown in discrete CMOS devices. However, in all cases studied, it is observed that immediate circuit failure during high voltage stress is prevented by the resistance of the driver element. Implications of these findings on circuit lifetime assessment are discussed.