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

Abstract

An advanced gate stack of Y-doped ZrO2 high-k dielectric is demonstrated for Ge MOSFETs. ZrO2 is implemented due to its high-permittivity (high-k) value, and additional Y is doped into the ZrO2 to enhance interfacial properties. The gate stack of ZrO2 with 2 similar to 4% Y doping shows improved electrical properties, achieving an EOT of 0.67 nm, a low interface trap density (Dit) of 1.2 x 10(12) eV(-1) cm(-2), a record-low gate leakage current of 1.14 x 10(-7) A/cm(2) at -1 V, and peakmobility of 68 cm(2)/V.s. The proposed gate stack would enhance transistor speed and save power consumption of Ge MOSFETs.