Crystalline ZrTiO$_{bf 4}$-Gated Ge Metal–Oxide–Semiconductor Devices With Amorphous Yb$_{bf 2}$ O$_{bf 3}$ as a Passivation Layer

摘要

An amorphous Yb$_{2}$O $_{3}$ passivation layer integrated with a crystalline ZrTiO $_{4}$ film was explored as the advanced gate stack for Ge MOS devices. The ZrTiO $_{4}$/Yb$_{2}$O $_{3}$ gate stack demonstrates $D_{rm it}$ of 2.4 × 10$^{11}$ cm $^{-2}cdot, $eV$^{-1}$ and EOT down to 0.76 nm which are, respectively, due to the formation of an interfacial YbGeO $_{x}$ layer that well passivates the dangling bonds at Ge surface and the adoption of a crystalline ZrTiO$_{4}$ film with a κ value of 45.6. The gate stack also shows low leakage current, tight distribution of device parameters, and desirable reliability performance, paving an alternative avenue to develop high-performance Ge MOS devices.