Atomic-scale smoothing of semiconducting oxides via plasma-enabled atomic-scale reconstruction

Zhang，Yongjie1,2; Tang，Jin1; Liang，Shaoxiang1; Zhao，Junlei3; Hua，Mengyuan3; Zhang，Chun2; Deng，Hui1

2024-03-01

10.1016/j.ijmachtools.2024.104119

International Journal of Machine Tools and Manufacture   影响因子和分区

0890-6955

β-GaO, known as a next-generation wide-bandgap transparent semiconducting oxide (TSO), has considerable application potential in ultra-high-power and high-temperature devices. However, fabricating a smooth β-GaO substrate is challenging owing to its strong mechanical strength and chemical stability. In this study, an atomic-scale smoothing method named plasma-enabled atomic-scale reconstruction (PEAR) is proposed. We find that three reconstruction modes, namely, 2D-island, step-flow, and step-bunching, can be identified with the increase in the input power; only the step-flow mode can result in the formation of an atomically smooth β-GaO surface (Sa = 0.098 nm). Various surface and subsurface characterizations indicate that the smooth β-GaO surface shows excellent surface integrity, high crystalline quality, and remarkable photoelectric properties. The atomic-scale density functional theory-based calculations show that the diffusion energy barrier of a Ga atom is only 0.46 eV, thereby supporting the atomic mass migration induced by high-energy plasma irradiation in the experiment. Nanoscale molecular dynamics simulations reveal that O atoms firstly migrate to crystallization sites, followed by Ga atoms with a lower migration rate; reconstruction mainly proceeds along the <010> direction and then expands along the <100> and <001> directions. The millimeter-scale numerical simulations based on the finite element method demonstrate that the coupling of the thermal and flow fields of plasma is the impetus for PEAR of β-GaO. Furthermore, the smoothing generality of PEAR is demonstrated by extending it to other common TSOs (α-AlO, ZnO, and MgO). As a typical plasma-based atomic-scale smoothing method, PEAR is expected to enrich the theoretical and technological knowledge on atomic-scale manufacturing.

Atmospheric plasma Atomic-scale manufacturing Atomic-scale smoothing Semiconducting oxides Single crystal β-Ga2O3 Surface reconstruction

SCI ; EI

英语

第一 ; 通讯

ENGINEERING

2-s2.0-85182269820

Scopus

1.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
2.Department of Physics and Centre for Advanced 2D Materials,National University of Singapore,2 Science Drive 3, Singapore,117551,Singapore
3.Department of Electrical and Electronic Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China

Zhang，Yongjie,Tang，Jin,Liang，Shaoxiang,et al. Atomic-scale smoothing of semiconducting oxides via plasma-enabled atomic-scale reconstruction[J]. International Journal of Machine Tools and Manufacture,2024,196.

Zhang，Yongjie.,Tang，Jin.,Liang，Shaoxiang.,Zhao，Junlei.,Hua，Mengyuan.,...&Deng，Hui.(2024).Atomic-scale smoothing of semiconducting oxides via plasma-enabled atomic-scale reconstruction.International Journal of Machine Tools and Manufacture,196.

Zhang，Yongjie,et al."Atomic-scale smoothing of semiconducting oxides via plasma-enabled atomic-scale reconstruction".International Journal of Machine Tools and Manufacture 196(2024).