High quality ultra thin CVD HfO₂ gate stack with poly-Si gate electrode

We have developed and demonstrated an in-situ rapid thermal CVD (RTCVD) process for the fabrication of high quality ultra thin CVD HfO₂ gate stack that is compatible with conventional self-aligned poly-Si gate technology. These poly-Si gated HfO₂ gate stack show excellent interface properties, EOT=10.4Å, and leakage current Jg=0.23mA/cm² @Vg=-1V which is several orders of magnitude lower than RTO SiO₂ with poly-Si gate. In addition, the HfO₂ gate stack is thermally stable in direct contact with n⁺-poly Si gate under typical dopant activation conditions. These films also show excellent reliability under high-field electrical stress. We have also fabricated and demonstrated NMOSFETs, and studied boron penetration in HfO₂ gate stack with p⁺-poly Si gate.