Conformal hexagonal-boron nitride dielectric interface for tungsten diselenide devices with improved mobility and thermal dissipation.

Liu, Donghua; Chen, Xiaosong; Yan, Yaping; Zhang, Zhongwei; Jin, Zhepeng; Yi, Kongyang; Zhang, Cong; Zheng, Yujie et al. · Nat Commun · 2019

basic_science · Level V

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Abstract

Relatively low mobility and thermal conductance create challenges for application of tungsten diselenide (WSe<sub>2</sub>) in high performance devices. Dielectric interface is of extremely importance for improving carrier transport and heat spreading in a semiconductor device. Here, by near-equilibrium plasma-enhanced chemical vapour deposition, we realize catalyst-free growth of poly-crystalline two-dimensional hexagonal-boron nitride (2D-BN) with domains around 20~ 200 nm directly on SiO<sub>2</sub>/Si, quartz, sapphire, silicon or SiO<sub>2</sub>/Si with three-dimensional patterns at 300 °C. Owing to the atomically-clean van-der-Walls conformal interface and the fact that 2D-BN can better bridge the vibrational spectrum across the interface and protect interfacial heat conduction against substrate roughness, both improved performance and thermal dissipation of WSe<sub>2</sub> field-effect transistor are realized with mobility around 56~ 121 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup> and saturated power intensity up to 4.23 × 10<sup>3</sup> W cm<sup>-2</sup>. Owing to its simplicity, conformal growth on three-dimensional surface, compatibility with microelectronic process, it has potential for application in future two-dimensional electronics.