Analysis of Threshold Voltage Flexibility in Ultrathin-BOX SOI FinFETs

Kazuhiko Endo,Hitomi Yamauchi,Meishoku Masahara,Hiroyuki Ota,Shin-Ichi O'Uchi,Takashi Matsukawa,Shinji Migita,Wataru Mizubayashi,Yuki Ishikawa,Junji Tsukada,Yukinori Morita

doi:10.3390/jlpea4020110

Abstract

A threshold voltage (Vth) controllable multigate FinFET on a 10-nm-thick ultrathin BOX (UTB) SOI substrate have been investigated. It is revealed that the Vth of the FinFET on the UTB SOI substrate is effectively modulated thanks to the improved coupling between the Si channel and the back gate. We have also carried out analysis of the Vth controllability in terms of the size dependence such as the gate length (LG) and the fin width (TFin).

Highlights

A threshold voltage (Vth) controllable multigate FinFET on a 10-nm-thick ultrathin BOX (UTB) SOI substrate have been investigated
The capacitance equivalent thickness (CET) of the UTBOX is measured as 11.5 nm and the uniformity of the UTBOX thickness is as good as that of the thermal SiO2
The Vth controllable FinFETs using the 10-nm-thick UTB SOI substrate have been successfully fabricated and controllability of the Vth is analyzed in terms of the size dependence

Summary

Introducttion

Recently,, complemeentary metal oxide sem miconductor (CMOS) device d technnology has faced f several difficulties. A doped silicon channnel is effective for Vth tu uning; it causse severe vaariability duue to the ran ndom dopan nt fluctuatioon [7,8]. Vth conttrol by the substrate back b bias haas been invvestigated fo or the planaar devices d [11––14]. Effectiv veness of thhe back gatee bias on thee Vth of the FinFET is different duue to o the narroow channell. Recently,, we have demonstratted a flexib ble Vth tuni ning for thee FinFET by b controlling c tthe back biaas using a 10-nm-thick k ultra-thin (UT) buried oxide In this stuudy, we hav ve extendedd the analyssis of Vth fleexibility in terms of th he LG and thhe

Thhe th hermal SiO

Device F

Results and Discussion

Conclusions