Subthreshold behavior models for nanoscale junctionless double-gate MOSFETs with dual-material gate stack

Abstract

By using a variable separation technique, an analytical model of the two-dimensional (2D) channel electrostatic potential for junctionless dualmaterial double-gate (JLDMDG) MOSFETs is derived from the 2D Poisson's equation. On the basis of the 2D channel electrostatic potential and the current continuity equation, a subthreshold current model is obtained. The advantages of JLDMDG MOSFETs are proved by comparing the central electrostatic potential and electric field distribution with those of junctionless single-material double-gate (JLSMDG) MOSFETs. In addition, the influence of different device parameters (such as body thickness, oxide thickness, and the ratio of gate length) on subthreshold current and subthreshold slope is investigated. It is found that a smaller body thickness or gate oxide thickness or a longer control gate induces a better subthreshold performance. The data extracted from the developed model are in good accordance with simulation results obtained from DESSIS.

Single-event-transient effects in Junctionless Double-Gate MOSFETs with Dual-Material Gate investigated by 3D simulation

“…In addition, the electric field peak at the drain is considerably reduced, which suppresses HCEs [5][6]. JL-DMDG is then a promising structure for which extensive modelling works have been reported in the literature [7][8] in the last years. However, at the best of our knowledge, radiation-sensitivity studies of these devices have not been performed.…”

Potential‐based threshold voltage and subthreshold swing models for junctionless double‐gate metal‐oxide‐semiconductor field‐effect transistor with dual‐material gate

“…To overcome these problems, a dual‐material gate (DMG) structure has been proposed and applied to improve the performance of JL MOSFET . Recently, a novel structure called junctionless dual‐material double‐gate (JLDMDG) MOSFET has been proposed, and its electrical characteristic has been investigated by using three‐dimensional (3D) numerical simulations . Although analytical models of the two‐dimensional (2D) channel electrostatic potential and subthreshold current for JLDMDG MOSFET have been derived from the 2D Poisson's equation, no analytical threshold voltage model for JLDMDG MOSFET has been proposed until now.…”

“…Recently, a novel structure called junctionless dual‐material double‐gate (JLDMDG) MOSFET has been proposed, and its electrical characteristic has been investigated by using three‐dimensional (3D) numerical simulations . Although analytical models of the two‐dimensional (2D) channel electrostatic potential and subthreshold current for JLDMDG MOSFET have been derived from the 2D Poisson's equation, no analytical threshold voltage model for JLDMDG MOSFET has been proposed until now. The short‐channel threshold voltage decay plays a very important role in device application and is very sensitive to the device parameters such as silicon‐film thickness, gate oxide thickness, drain bias, and channel length .…”

Theoretical Investigation of Dual Material Junctionless Double Gate Transistor for Analog and Digital Performance

“…Moreover, high channel doping concentration reduces carrier mobility which in turn affects drive current and subsequently resulting in lower transconductance [6]- [8]. This problem can be overcome using dual material gate (DMG) on to the double gate JL (DM-JL-DG) transistor, i.e., two metal gates having different work functions.…”

“…Preliminary study on DM-JL-DG architecture using ATLAS 3-D device simulation has already been presented using parabolic approach [7]. Recently, evanescent mode analysis-based subthreshold drain current model for DM-JL-DG has also been reported [8].…”