Analytical Modeling and Simulation of Dual-Material Surrounding-Gate Metal–Oxide–Semiconductor Field Effect Transistors with Single-Halo Doping

Abstract

We present a modified surrounding-gate metal-oxide-semiconductor field effect transistor (MOSFET), in which the gate consists of two metals with different work functions, and single-halo doping is added to the channel near the source end. The performance of the modified structure was studied by developing physics-based analytical models for the surface potential, electric field, and threshold voltage. It is shown that the novel MOSFET could significantly reduce threshold voltage roll-off and drain-induced barrier lowering, and simultaneously improve carrier transport efficiency by carefully configuring the halo doping and work functions of the dual-material gate. The results predicted using the models are compared with those obtained with the three-dimensional simulator Davinci to verify the accuracy of the proposed analytical models.

Dual material gate-graded channel-gate stack (DMG-GC-Stack) surrounding gate MOSFET: Analytical threshold voltage (V<inf>TH</inf>) and subthreshold swing (S) models

“…The results obtained are compared to results for (DMG-GC)-Surrounding gate MOSFET [11]. Figure 1 shows the schematic cross section of the new structure DMG-GC-Stack-SG MOSFET.…”

Analytical Threshold Model for Nanoscale Cylindrical Surrounding-Gate Metal–Oxide–Semiconductor Field Effect Transistor with High-κ Gate Dielectric and Tri-Material Gate Stack

“…Among them, cylindrical surrounding-gate (CSG) MOSFET is considered one of the most promising candidates owing to its excellent control of the channel. [2][3][4][5][6][7][8] However, even in CSG MOSFET, SCEs and HCEs cannot be neglected for channel lengths below 100 nm. 9) To enhance the immunity against SCEs, a tri-material gate (TMG) MOSFET has been proposed, [10][11][12] taking three different metal gates with different work functions as gate electrodes.…”

“…[16][17][18] Combining the advantages of the triple-material metal gate, two-layer high-gate dielectric stack, and CSG structure, in this paper, we propose a novel device structure that is called the cylindrical surrounding-gate MOSFET with high-gate dielectrics and tri-material gate stack (TMGCSG). The TMGCSG structure divides the cylindrical silicon channel into three continuous regions, which is similar to dual-material surrounding-gate MOSFET with single-halo doping proposed by Li et al 6) The threshold voltage model based on the parabolic potential approximation (PPA) was also proposed by them. However, PPA cannot be used to simulate the very short thick-body MOSFET for its inherent drawback of its lack of a precise potential description.…”