A 14nm logic technology using 2nd-generation FinFET transistors with a novel subfin doping technique, self-aligned double patterning (SADP) for critical patterning layers, and air-gapped interconnects at performance-critical layers is described. The transistors feature rectangular fins with 8nm fin width and 42nm fin height, 4th generation high-k metal gate, and 6th-generation strained silicon, resulting in the highest drive currents yet reported for 14nm technology. This technology is in high-volume manufacturing.

Stress Induced Leakage Current (SILC) has been observed on non-optimized high-K (HK) and metal-gate (MG) transistors. Large NMOS PBTI degradation and correlation to SILC increase on such gate stack is a result of large trap generations in the bulk-HK. This poses a long term reliability concern on product standby power and can limit the operating voltage if not suppressed. On an optimized HK+MG process, we demonstrate that SILC has been suppressed. The transistor level SILC data, model and Product burn-in stress data support this. With optimized process, SILC has no impact on products made of 45nm HK+MG transistors.

Two key process features that are used to make 45 nm generation metal gate + high-k gate dielectric CMOS transistors are highlighted in this paper. The first feature is the integration of stress-enhancement techniques with the dual metal-gate + high-k transistors. The second feature is the extension of 193 nm dry lithography to the 45 nm technology node pitches. Use of these features has enabled industry-leading transistor performance and the first high volume 45 nm high-k + metal gate technology.

In this paper, we present extensive breakdown results on our 45nm HK+MG technology. Polarity dependent breakdown and SILC degradation mechanisms have been identified and are attributed gate and substrate injection effects. Processing conditions were optimized to achieve comparable TDDB lifetimes on HK+MG structures at 30% higher E-fields than SiON with a reduction in SILC growth. Extensive long-term stress data collection results and a change in voltage acceleration are reported.

In this paper, Bias-temperature instability (BTI) characterization on 45nm high-K + metal-gate (HK+MG) transistors is presented and degradation mechanism is discussed. Transistors with an unoptimized HK film stack in the early development phase exhibited pre-existing traps and large amount of hysteresis that was consistent with literature. The optimized and final HK process demonstrated NMOS and PMOS BTI on HK+MG transistors that are better than that of SiON at matched E-fields and comparable at targeted 30% higher use fields. The final process also showed no hysteresis due to fast traps thereby allowing us to characterize its intrinsic degradation mechanism. On the optimized process, NMOS BTI is attributed primarily to electron trapping in the HK bulk and HK/SiON interfacial layer (IL) regions. PMOS BTI degradation, on the other hand, is mainly interface driven and is found to be very similar to that observed on conventional SiON transistors.