No abstract

High-quality, ultrathin chemical vapor deposition (CVD) hafnium oxynitride (HfOxNy) gate dielectric with poly-silicon (Si) gate electrode has been investigated for the first time. This CVD HfOxNy gate dielectric film remains amorphous after 950 C N 2 annealing. Compared with HfO 2 films with poly-Si gate electrode and similar equivalent oxide thickness (EOT), CVD HfOxNy shows significantly reduction in leakage-current density and boron penetration and superior thermal and electrical stability.Index Terms-Boron penetration, chemical vapor deposition (CVD), hafnium oxide, hafnium oxynitride, thermal stability.

No abstract

No abstract

No abstract

A high-quality HfO2 gate stack with equivalent oxide thickness (EOT) of 7.8 Å and a leakage current of Jg=0.5 mA/cm2 @ Vg=−1.0 V has been achieved by an in situ rapid thermal chemical vapor deposition process. It is found that both NH3-based interface layer and N2 postdeposition annealing are very effective in reducing EOT and leakage, and at the same time, improving film qualities. These HfO2 gate stacks show negligible frequency dependence, small hysteresis in capacitance–voltage (C–V) and weak temperature dependence of the leakage current. They also show negligible charge trapping at high voltage stress.

MOSFETs with high quality ultra thin (EOT-10.3A) Hf02 gate stacks and self-aligned dual poly-Si gate are fabricated and characterized. Both n-and p-MOSFETs show good electron and hole mobility, respectively, and excellent sub-threshold swings. In addition, Hf02 gate stack exhibits excellent thermal stability with poly-Si gate up to 1O5O0C/30s gate activation annealing and shows excellent TDDB reliability characteristics with negligible charge trapping and SILC under high-field stressing.

Post-deposition annealing was investigated for hafnium silicate films deposited on Si substrates by atomic layer deposition. Annealing in NH3 at 750°C incorporated 13 At.% nitrogen in hafnium silicate, and hysteresis significantly depended on film thickness. In contrast, annealing in N2 at 950°C suppressed hysteresis and its dependence on the film thickness. In addition, effective mobility and positive bias temperature instability were improved by N2 annealing of as-deposited hafnium silicate films. Finally, additional N2 annealing following NH3 annealing was effective to obtain highly dense hafnium silicate films with good mobility and optimized nitrogen incorporation.