Characterization of HfSiON Gate Dielectric with TiN Gate on Multi-Gate MOSFET

The hysteresis and mobilities of 1nm EOT HfSiON dielectric on Multi-Gate MOSFET (MuGFET) with TiN metal gate were studied. We did not observe any drain current hysteresis. This is consistent with the same gate stack on planar bulk MOSFET. However, we found significant electron and hole mobility degradation for MuGFET compared to SiO2 control devices (up to -25%). The percentage of degradation is higher than the same gate stack on planar bulk MOSFET, which points to the poor interfacial oxide quality on the MuGFET fin sidewalls.