Impact of low/high-κ spacer-source overlap on characteristics of tunnel dielectric based tunnel field-effect transistor  

作　　者：JIANG Zhi ZHUANG Yi-qi LI Cong WANG Ping LIU Yu-qi 蒋智;庄奕琪;李聪;王萍;刘予琪

机构地区：[1]School of Microelectronics,Xidian University,Xi’an 710071,China

出　　处：《Journal of Central South University》2017年第11期2572-2581,共10页中南大学学报（英文版）

基　　金：Projects(61574109,61204092)supported by the National Natural Science Foundation of China

摘　　要：The effects of low-κ and high-κ spacer were investigated on the novel tunnel dielectric based tunnel field-effect transistor(TD-FET) mainly based upon ultra-thin dielectric direct tunneling mechanism. Drive currents consist of direct tunneling current and band-to-band tunneling(BTBT) current. Meanwhile, tunneling position of the TD-FET differs from conventional tunnel-FET in which the electron and hole tunneling occur at intermediate rather than surface in channel(or source-channel junction under gate dielectric). The 2-D nature of TD-FET current flow is also discussed that the on-current is degraded with an increase in the spacer width. BTBT current will not begin to play part in tunneling current until gate voltage is 0.2 V. We clearly identify the influence of the tunneling dielectric layer and spacer electrostatic field on the device characteristics by numerical simulations. The inserted Si_3N_4 tunnel layer between P+ region and N+ region can significantly shorten the direct and band-to-band tunneling path, so a reduced subthreshold slope(Ss) and a high on-current can be achieved. Above all the ambipolar current is effectively suppressed, thus reducing off-current. TD-FET demonstrates excellent performance for low-power applications.The effects of low-κ and high-κ spacer were investigated on the novel tunnel dielectric based tunnel field-effect transistor(TD-FET) mainly based upon ultra-thin dielectric direct tunneling mechanism. Drive currents consist of direct tunneling current and band-to-band tunneling(BTBT) current. Meanwhile, tunneling position of the TD-FET differs from conventional tunnel-FET in which the electron and hole tunneling occur at intermediate rather than surface in channel(or source-channel junction under gate dielectric). The 2-D nature of TD-FET current flow is also discussed that the on-current is degraded with an increase in the spacer width. BTBT current will not begin to play part in tunneling current until gate voltage is 0.2 V. We clearly identify the influence of the tunneling dielectric layer and spacer electrostatic field on the device characteristics by numerical simulations. The inserted Si_3N_4 tunnel layer between P+ region and N+ region can significantly shorten the direct and band-to-band tunneling path, so a reduced subthreshold slope(Ss) and a high on-current can be achieved. Above all the ambipolar current is effectively suppressed, thus reducing off-current. TD-FET demonstrates excellent performance for low-power applications.

关 键 词：tunnel dielectric based tunnel field-effect transistor tunnel field-effect transistor band-to-band tunneling tunneling dielectric layer subthreshold slope off-current on-current 

分 类 号：TN386[电子电信—物理电子学]