Monolayer MoS2 Enabled Single-Crystalline Growth of AlN on Si(100) Using Low-Temperature Helicon Sputtering

• Published in: ACS applied nano materials Vol. 2; no. 4; pp. 1964 - 1969
• Main Authors: Hsu, Wei-Fan, Lu, Li-Syuan, Kuo, Po-Chun, Chen, Jie-He, Chueh, Wei-Chen, Yeh, Han, Kao, Hui-Ling, Chen, Jyh-Shin, Chang, Wen-Hao
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.04.2019
• Subjects: highly oriented MoS2 monolayer; single-crystalline AlN film; low-temperature sputtering; Transition metal dichalcogenide; van der Waals epitaxy
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.8b02358

Growing a single-crystalline film on a substrate relies on the compatibility of crystal symmetry and lattice constant between the two materials. Such limitations can be circumvented by introducing van der Waals epitaxy of three-dimensional (3D) crystals on two-dimensional (2D) layered materials. Recently, buffer-assisted growth of III-nitride films on graphene has been demonstrated. However, the low chemical reactivity of graphene surface considerably limits the large-area and single-crystalline growth of planar 3D films on 2D layered materials. Here, we demonstrate that using highly oriented monolayer MoS2 as a buffer layer, single-crystalline AlN thin films can be grown on Si(100) substrates, which possess a different crystal symmetry with the films. The AlN films were grown by helicon sputtering system at low temperature (400 °C), showing a very flat surface with a root-mean-square roughness of 1.0 nm and an X-ray rocking curve with a full width at half-maximum of 0.336°, indicating a high-crystalline quality. Because the buffer layer as well as the AlN films were prepared at low temperatures, our results not only pave the way for integrating III-nitride with the Si wafer industry process but also open a new possibility for growing III-nitride thin film on various foreign substrates.