A Simple Approach to Fabrication of High-Quality HfSiON Gate Dielectrics With Improved nMOSFET Performances

A simple technique to form high-quality hafnium silicon oxynitride (HfSiON) by rapid thermal processing oxidation of physical vapor deposition hafnium nitride (HfN) thin films on ultrathin silicon oxide (SiO/sub 2/) or silicon oxynitride (SiON) layer is presented. Metal TaN gate electrode is also introduced into such HfSiON stacks. Excellent performances including large electron mobility (85%SiO/sub 2/at0.2 MV/cm), low leakage current (10/sup -4/ of SiO/sub 2/), and superior time-dependant dielectric breakdown reliability are achieved in HfSiON/SiO/sub 2/ stacks, and these results suggest such stacks are very promising for the low-power SOC applications in the near future. In addition, the improvement of the electron mobility in this HfSiON/SiO/sub 2/ stack by a reduction of the border traps in the HfSiON dielectric is demonstrated.