Low Ge Content Ultra-Thin Fin Width (5nm) Monocrystalline SiGe n-Type FinFET With Low Off State Leakage and High I_ON/I_OFF Ratio

Abstract

We successfully fabricate the Si0.8Ge0.2 channel fin field-effect-transistor (FinFET) with 5 nm ultra-thin fin width and high aspect ratio (~10×) on silicon-on-insulator (SOI) substrate by simple two-step dry etching. In comparison of the conventional Si FinFET, our proposed SiGe ultra-thin FinFETs (Si0.8Ge0.2 UT-FinFET) at VD = 0.75 V & VG = 1.5 V shows higher ON-state current (1 mA/fin), even achieve lower OFF-state current (0.2 nA/fin) and steep subthreshold slope (SS) of 76 mV/decade, which is owing to the better gate control given by the ultra-thin fin channel. In addition, this work also exhibits the suppression of short channel effect (SCE) with very small drain induced barrier-lowering (DIBL) of 4 mV/V.

Keywords

• FinFET
• SiGe
• high mobility
• ultra-thin fin
• short channel effect