Graphene nanoribbon tunnel field effect transistor with lightly doped drain: Numerical simulations

• Published in: Superlattices and microstructures 2014-11, Vol.75, p.245-256
• Main Authors: Ghoreishi, Seyed Saleh, Saghafi, Kamyar, Yousefi, Reza, Moravvej-Farshi, Mohammad Kazem
• Format: Article
• Language: English
• Subjects: Ambipolarity; Band to band tunneling (BTBT); Channels; Computer simulation; Drain induced barrier thinning (DIBT); Drains; Field effect transistors; Graphene; Graphene nanoribbon (GNR); Nanostructure; Non equilibrium Green’s function (NEGF); Semiconductor devices; Tunneling field effect transistor (TFET); Tunnels (transportation)
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2014.07.042

•We propose a new structure by modification of the tunneling GNRFET.•A lightly doped region was used at the drain side of the channel.•The proposed structure suppressed the ambipolar current.•The proposed structure enjoys from better switching and OFF-state behavior.•The proposed structure also shows a lesser size of DIBT. By inserting a lightly doped region between the highly doped drain and the intrinsic channel of a graphene nanoribbon tunnel field effect transistor (GNR-TFET), we propose a new lightly doped drain (LDD)-GNR-TFET. Transport characteristics of the proposed transistor is numerically simulated, employing the third-nearest-neighbor tight-binding approximation in mode space non-equilibrium Green’s function formulism (NEGF), in ballistic regime. Simulations show, in comparison with a conventional GNR-TFET of the same dimensions, the proposed LDD-GNR-TFET exhibits a 102–103 times smaller OFF-current, an up to 105 times larger ON/OFF ratio, a shorter time delay, a smaller power-delay product (PDP) and a less drain induced barrier thinning (DIBT), besides preserving the subthreshold swing.