Role of oxygen in surface kinetics of SiO2 growth on single crystal SiC at elevated temperatures

Zhang，Yongjie1; Liang，Shaoxiang1; Zhang，Yi1,2; Li，Rulin1; Fang，Zhidong1; Wang，Shuai1; Deng，Hui1

2021-01-15

10.1016/j.ceramint.2020.09.014

CERAMICS INTERNATIONAL   影响因子和分区

0272-8842

1873-3956

Understanding surface kinetics of SiO2 growth on single crystal SiC at elevated temperatures is crucial to fabricate high-performance SiC-based devices. However, the role of oxygen in the evolution mechanism of SiC surface at atomic scale has not been comprehensively elaborated. Here, we reveal the manipulation effect of oxygen on the competitive growth of thermal oxidation SiO2 (TO-SiO2) and thermal chemical vapor deposition SiO2 (TCVD-SiO2) on the 4H-SiC substrate at 1500 degrees C. TO-SiO2 is formed by the thermal oxidation of SiC, in which the substrate undergoes layer-by-layer oxidation, resulting in an atomically flat SiC/TO-SiO2 interface. TCVD-SiO2 growth includes the sublimation of Si atoms, the reaction between sublimated Si atoms and reactive oxygen, and the adsorption of gaseous SixOy species. A relatively high sublimation rate of Si atoms at SiC atomic steps causes the transverse evolution of the nucleation sites, leading to the formation of nonuniform micron-sized pits at the SiC/TCVD-SiO2 interface. The low oxygen concentration favors TCVD-SiO2 growth, whose crystal quality is much better than that of TO-SiO2 due to the high surface mobility in the thermal CVD process. We further achieve the epitaxial growth of graphene on 4H-SiC in an almost oxygen-free reaction atmosphere. Additionally, ReaxFF reactive molecular dynamic simulation results illustrate that the decrease in oxygen concentration can promote the growth kinetics of SiO2 on single crystal SiC from being dominated by thermal oxidation to being dominated by thermal CVD.

Single crystal SiC Thermal oxidation Thermal CVD Oxygen concentration Surface kinetics

SCI ; EI

英语

第一 ; 通讯

Science and Technology Innovation Committee of Shenzhen Municipality, Shenzhen, China["KQTD20170810110250357","GJHZ20180928155412525"]

Materials Science

Materials Science, Ceramics

WOS:000597774500003

ELSEVIER SCI LTD

20203709171604

Silicon carbide ; Gas adsorption ; Thermooxidation ; Reaction kinetics ; Molecular dynamics ; Atoms ; Crystal atomic structure ; Silicon ; Sublimation ; Chemical vapor deposition ; Growth kinetics ; Kinetics ; Silica ; Silicon oxides

Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Fluid Flow, General:631.1 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Chemical Operations:802.3 ; Chemical Products Generally:804 ; Inorganic Compounds:804.2 ; Classical Physics; Quantum Theory; Relativity:931 ; Atomic and Molecular Physics:931.3 ; Crystalline Solids:933.1 ; Crystal Lattice:933.1.1

MATERIALS SCIENCE

Web of Science

1.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Engineering,Faculty of Science,University of East Anglia,Norwich,Norwich Research Park,NR4 7TJ,United Kingdom

Zhang，Yongjie,Liang，Shaoxiang,Zhang，Yi,et al. Role of oxygen in surface kinetics of SiO2 growth on single crystal SiC at elevated temperatures[J]. CERAMICS INTERNATIONAL,2021,47(2):1855-1864.

Zhang，Yongjie.,Liang，Shaoxiang.,Zhang，Yi.,Li，Rulin.,Fang，Zhidong.,...&Deng，Hui.(2021).Role of oxygen in surface kinetics of SiO2 growth on single crystal SiC at elevated temperatures.CERAMICS INTERNATIONAL,47(2),1855-1864.

Zhang，Yongjie,et al."Role of oxygen in surface kinetics of SiO2 growth on single crystal SiC at elevated temperatures".CERAMICS INTERNATIONAL 47.2(2021):1855-1864.