Ultrathin EOT (0.67 nm) High-k Dielectric on Ge MOSFET Using Y Doped ZrO2 With Record-Low Leakage Current

An advanced gate stack of Y-doped ZrO
₂
high-k dielectric is demonstrated for Ge MOSFETs. ZrO
₂
is implemented due to its high-permittivity (high-k) value, and additional Y is doped into the ZrO
₂
to enhance interfacial properties. The gate stack of ZrO
₂
with 2~4% Y doping shows improved electrical properties, achieving an EOT of 0.67 nm, a low interface trap density (Dit) of 1.2 x 1012 eV
^-1
cm
^-2
, a record-low gate leakage current of 1.14 x 10
^-7
A/cm
²
at -1 V, and peak mobility of 68 cm
²
/V·s. The proposed gate stack would enhance transistor speed and save power consumption of Ge MOSFETs.