MOS characteristics of ultrathin CVD HfAlO gate dielectrics

Thermally stable, high-quality ultrathin (EOT 13 Angstrom) CVD HfAlO gate dielectrics with poly-Si gate electrode have been investigated for the first time. Results, demonstrate that while in situ doping with Al significantly increases the crystallization temperature of HfO2 no to 900 degreesC and improves its thermal stability, it also introduces. negative fixed oxide charges due to Al accumulation at the HfAlO-Si interface, resulting in mobility degradation. The effects of Al concentration on crystallization temperature, fixed oxide charge density, and mobility degradation in HfAlO have been characterized and correlated.