Performance Limits of the Self‐Aligned Nanowire Top‐Gated MoS₂ Transistors

Abstract

In order to realize the promising potential of MoS 2 as the alternative channel material, it is essential to achieve high-performance top-gated MoS 2 fieldeffect transistors (FETs), especially since the back-gated counterparts cannot control the device individually. Although uniform high-k dielectric films, such as HfO 2 , can be obtained through the introduction of artificial nucleation sites on the MoS 2 channel to fabricate top-gated FETs, this would inevitably degrade their channel/dielectric interface quality, induce significant charged impurity scattering and lower carrier mobility. In this work, MoS 2 FETs are fabricated using a self-aligned nanowire top-gate, which can effectively reduce the charged impurity scattering on the surface of MoS 2 . Specifically, the fabricated short-channel devices exhibit impressive electrical performances, such as the high on/off current ratio, low interface trap density, and near-ideal subthreshold slope at room temperature. In addition, the short channel effect is systematically analyzed, which indicates that the phonon scattering can be the dominant scattering mechanism in the devices when the amount of charged impurities is effectively reduced with the self-aligned nanowire gate. All these provide an enhanced fabrication scheme to attain top-gated shortchannel devices with the optimized interface and potentially to explore their corresponding performance limits.

Two‐dimensional heterostructure promoted infrared photodetection devices

“…Designing new architectures or exploring new fabrication techniques to realize more precise and improved IR photodetection, have attracted many scientists . Son et al discovered a fabrication method to build integrated 3D electronic and optoelectronic 2DHs with graphene stops that consisted of graphene/fluorographene heterostructures (shown in Figure E).…”

“…Designing new architectures or exploring new fabrication techniques to realize more precise and improved IR photodetection, have attracted many scientists. [89][90][91] Son et al 77 discovered a fabrication method to build integrated 3D F I G U R E 4 A, Electric field intensity-dependent band alignments and the Schottky barrier in the WSe 2 /grephene heterojunctions. Reproduced with permission.…”

Black phosphorus electronics

“…Fig. 2 demonstrates carrier mobilities versus current on/off ratio reported for field-effect transistors based on typical 2D materials including graphene [4,[19][20][21][22][23][24], TMDs [7,[25][26][27][28][29][30][31][32] and BP [8,25,[33][34][35][36][37][38][39]. As shown in Fig.…”

Liquid‐Alloy‐Assisted Growth of 2D Ternary Ga2In4S9 toward High‐Performance UV Photodetection

“…As shown in Figure a,b, the dark output characteristics (Ga 2 In 4 S 9 with 10 L) and the transfer characteristics (Ga 2 In 4 S 9 with different thicknesses) imply that the Ga 2 In 4 S 9 channel owns a representative n‐type semiconducting behavior with an on/off current ratio ≈10 7 . The carrier (electrons) mobility ( µ e ) is determined to be 1.3 cm 2 V −1 s −1 for 10 L Ga 2 In 4 S 9 based on the expressionwhere L is the channel length, W is the width, C i refers to the capacitance per unit area (≈11.6 nF cm −2 for the 300 nm SiO 2 layer). And the device mobility generally increases with the increasing number of layers (0.1 and 2.2 cm 2 V −1 s −1 for 6 and 20 L Ga 2 In 4 S 9 , respectively).…”