Length and fin number dependence of ionizing radiation-induced degradation in bulk FinFETs

Abstract

Ultra-small bulk FinFETs (dual-wel from a commercial process have been exposed dose. The devices have varying numbers of length. The devices show a significant incr leakage current, threshold voltage shift, trans subthreshold slope degradation after irra krad(SiO 2 ). The results also show a strong depe fin variation and trapped charge in the STI response of the devices.

A novel body-on-insulator (BOI) FinFET with excellent TID tolerance and scaling capability

“…Radiaition effects induced by space irradiation are the major threat to devices working in radiation environment [1,2]. Among them, the total ionizing dose (TID) effect is quite important [3], which may lead to device performance degradation, integrated circuits power consumption increases even function failure [4][5][6][7][8]. For conventional planar MOSFETs, with the scaling of device feature size down to nano region, MOS devices are inherently insensitive to TID irradiation.…”

“…FinFETs has become the mainstream commercial devices since 22 nm technology node due to its advantages such as strong gate control ability, low off-state leakage current (I off ), and improved short channel effects [5]. Due to its three-dimensional structure, the TID effect of FinFETs is different from planar MOSFETs and has aroused great interest recently [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. For bulk FinFETs, irradiation induced off-state leakage current increase is a concern.…”

“…For bulk FinFETs, irradiation induced off-state leakage current increase is a concern. It is mainly attributed to the irradiation induced positive charge trapping into shallow trench isolation (STI) [6][7][8]. The geometry of bulk FinFETs plays an important role in TID effect [9].…”

“…In addition, the irradiation induced I off degradation increases with fin pitch increasing [6]. The I off of irradiated bulk Fin-FETs increases with fin number decreasing [7]. For Silicon-On-Insulator (SOI) FinFETs, the negative shift of threshold voltage and increase of subthreshold swing (SS) after irradiation are observed, which are mainly attributed to the trapped charges of buried oxide (BOX) layer [14][15][16][17][18] and the fin/BOX interface states [19][20][21].…”