Concepedia

Epitaxial Germanium on SOI Substrate and Its Application of Fabricating High ${\rm I}_{\rm ON}/{\rm I}_{\rm OFF}$ Ratio Ge FinFETs

Cheng-Ting Chung, Che-Wei Chen, J. D. Lin, Che-Chen Wu, Chao-Hsin Chien, Guang-Li Luo, Chi‐Chung Kei, Chien‐Nan Hsiao

IEEE Transactions on Electron Devices · 2013 · 13 citations · 24 references

Abstract

Integrating germanium (Ge) thin film on silicon-on-insulator (SOI) substrate and fabricating Ge fin field-effect transistors (FinFETs) are demonstrated in this paper. Directly grown Ge film on a high-resistivity thin SOI substrate provides a good platform for fabricating advanced Ge devices. The SOI structure could effectively suppress junction leakage; therefore, high I ON / I OFF ratio (~5×10 5 , at VD =0.1 V) of the drain current is achieved. Tri-gate structure provides better short-channel control abilities for the Ge FinFETs, and the drain-induced barrier lowering and threshold voltage ( V TH ) shift can be maintained at the level of ~110 mV/V and ~ 0.1 V, respectively, for Ge n-channel FinFET with L channel =120 nm and W Fin =40 nm. Multifin Ge FinFET with L channel =170 nm and W Fin =50 nm is also illustrated. Both N - and P -FinFETs possess high I ON / I OFF ratio over 10 4 . Besides, the subthreshold swing could be reduced around 25% after forming gas annealing.