Ge/Si heterojunction L-shape tunnel field-effect transistors with hetero-gate-dielectric

• 来源期刊: 中国物理B（英文版）
• 关键词: tunnel field-effect transistors Ge/Si heterojunction hetero-gate-dielectric ambipolar effect
• 年，卷（期）: 2018,（7）
• 页码范围: 655-663
• 页数: 9页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/7/078502

摘要

A Ge/Si heterojunction L-shaped tunnel field-effect transistor combined with hetero-gate-dielectric (GHL-TFET) is proposed and investigated by TCAD simulation. Current–voltage characteristics, energy-band diagrams, and the distri-bution of the band-to-band tunneling (BTBT) generation rate of GHL-TFET are analyzed. In addition, the effect of the vertical channel width on the ON-current is studied and the thickness of the gate dielectric is optimized for better suppres-sion of ambipolar current. Moreover, analog/RF figure-of-merits of GHL-TFET are also investigated in terms of the cut-off frequency and gain bandwidth production. Simulation results indicate that the ON-current of GHL-TFET is increased by about three orders of magnitude compared with that of the conventional L-shaped TFET. Besides, the introduction of the hetero-gate-dielectric not only suppresses the ambipolar current effectively but also improves the analog/RF performance drastically. It is demonstrated that the maximum cut-off frequency of GHL-TFET is about 160 GHz, which is 20 times higher than that of the conventional L-shaped TFET.