Si bilayer tunnel field-effect transistor structure realized using tilted ion-implantation technique

• Published in: Solid-state electronics Vol. 180; p. 107993
• Main Authors: Kato, Kimihiko, Asai, Hidehiro, Fukuda, Koichi, Mori, Takahiro, Morita, Yukinori
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2021
• Subjects: Band-to-band tunnel; Gate-normal; Ion implantation; Sub-threshold swing; Tunnel FET; Gate-normal; Ion implantation; Sub-threshold swing; Band-to-band tunnel; Tunnel FET
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2021.107993

•A new device structure of Si tunnel field-effect transistor is proposed in a feasible manner by considering fabrication processes for future steep-slope switching devices.•The proposed device consists of a Si fin and a high impurity concentration at the fin surfaces, which are supposed to be realized using the tiled-ion-implantation technique.•The regions with a high impurity concentration are effective to generate gate-normal band-to-band tunneling and to create carrier conduction paths from the source to the drain, simultaneously.•Device simulation has revealed that steep on/off switching with a current ratio of more than 105 under an operating voltage of 0.3 V is achievable after careful optimization of the implanted impurity distributions. A new device structure for the Si tunnel field-effect transistor (TFET) is proposed along with feasible fabrication processes. The device consists of a Si fin with high impurity concentration at the fin surfaces, which are realized using the tilted-ion-implantation technique (TII) to effectively generate the gate-normal band-to-band tunneling (BTBT) and simultaneously create carrier conduction paths from the source to the drain. Device simulation revealed that the asymmetric impurity distribution, with a higher concentration on the source side and a lower concentration on the drain side controlled by the TII energy and angle, has potential for the realization of a high eGR/hGR by reducing the BTBT distance and a low off-state leakage. As a result, a steep on/off switching with a current ratio greater than 105 under an operating voltage of 0.3 V can be achieved by careful optimization of the implanted impurity distributions.