Band Edge Gate First HfSiON/Metal Gate n-MOSFETs using ALD-La 2 O 3 Cap Layers Scalable to EOT=0.68 nm for hp 32 nm Bulk Devices with High Performance and Reliability

Low Vth HfSiON/TaSiN gate first stacks have been demonstrated, using atomic-layer-deposition (ALD) La 2 O 3 cap layers, for half-pitch (hp) 32 nm-node metal gated bulk devices. By employing a very slow ALD-La 2 O 3 growth rate (0.036 nm/cycle) within 30 cycles, the smallest equivalent oxide thickness (EOT 2 /n-Poly Si devices. Thus, the drain currents are dramatically increased by using ALD-La 2 O 3 cap layers. Moreover, the positive-bias-temperature-instability (PBTI ) over a 10-year lifetime can be held to an acceptably low level at Vg = + 1.0 V.