Electrical properties of MOCVD HfO₂ dielectric layers with polysilicon gate electrodes for CMOS applications

Electrical properties of MOS capacitors using MOCVD HfO₂ as gate dielectric have been investigated. A 900°C 1s activation anneal of Ph-doped 680°C-RTCVD demonstrated a good compatibility with high-k layers. The best MOS capacitor is obtained with EOT=1.93 nm and Jg = 1.6E-04 A/cm² at |V_FB-1| which is > 2 orders of magnitude lower than SiO₂ with poly-Si gate. A minimal degradation of leakage current after 900°C activation anneal and low effect of temperature dependence reveal the thermal stability of MOCVD HfO₂ gate stack. Nevertheless, upon 1000°C activation anneal only the LPCVD poly resulted in working MOS capacitor. The found leakage current was > 2 order of magnitude higher compared to a 900°C activation anneal.