Along with the rapid development of modern electronics, the requirements for enhancing computing capabilities create challenges for improving device mobility and keeping them cool. To solve these problems, the dielectric interface, which dictates carrier transport and heat spreading in electrical devices, is of extreme importance. Plasma-enhanced chemical vapour deposition (PECVD) is a commonly-used and industry-compatible microelectronics technology.
 

By near-equilibrium PECVD, Wei’s group realize catalyst-free growth of poly-crystalline two-dimensional hexagonal-boron nitride (2D-BN) with domains around 20~200 nm directly on SiO2/Si, quartz, sapphire, silicon or SiO2/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 WSe2 field-effect transistor are realized with mobility around 56~ 121 cm2 V−1 s−1 and saturated power intensity up to 4.23×103 Wcm−2. Owing to its simplicity, conformal growth on three-dimensional surface, compatibility with microelectronic process, it has potential for application in future two-dimensional electronics.
                                       

     Figure a, STM of the h-BN sample. Figure b, the conformal h-BN grown on the 3D dielectric surface. Figure c, the device of FET with h-BN. Figure d and e, the heat transport across the 2D crystal/2D-BN/SiO2 interface and the 2D crystal/SiO2 interface. Figure f. the mobility and saturated power density of the FET device on SiO2/Si or 2D-BN/SiO2/Si.

     The related paper has been published in Nat. Commun., with Dr. Donghua Liu and Dr. Xiaosong Chen in the group as the first authors.

     See details: Donghua Liu; Xiaosong Chen; Yaping Yan; Zhongwei Zhang; Zhepeng Jin; Kongyang Yi; Cong Zhang; Yujie Zheng; Yao Wang; Jun Yang; Xiangfan Xu*; Jie Chen; Yunhao Lu; Dapeng Wei*; Andrew Thye Shen Wee; Dacheng Wei*. Conformal hexagonal-boron nitride dielectric interface for tungsten diselenide devices with improved mobility and thermal dissipation, Nature Communications 2019, 10, 1188.   

 Link：https://www.nature.com/articles/s41467-019-09016-0