Micro- to nano-scale topographical etching of diamond substrate via anisotropically atomic removal

• Published in: Applied surface science Vol. 655; p. 159589
• Main Authors: Shi, Yuqing, Chen, Zhaojie, Yang, Hao, Xie, Jin, Xu, Jingxiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2024
• Subjects: Atomic stripping; Diamond substrate; Graphitization; Oxidative etching; Structural dimensions; Diamond substrate; Atomic stripping; Structural dimensions; Oxidative etching; Graphitization
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.159589

[Display omitted] •A micro- to nano-scale etched topography is modelled on diamond substrate along crystal orientation.•The etched structure formation procedure is related to thermal oxidative and graphitization.•The structured size is subject to crystalline orientation, environmental temperature and catalytic metal element at the macro scale.•The structural size on substrate varies between the (100) and (111) surfaces, with an increasing trend as it approaches the (111) surface.•The micro- and nano-scale structures of diamond substrate may be transferred each other by the etching along crystal orientation. Substrate functionalization of diamond semiconductors rely on micro- and nano-topographical shapes and dimensions. However, an efficient and controllable fabrication is challenging due to its high hardness. In this study, a micro- to nano-scale etched topography model is proposed on the machined diamond substrate related to graphitization along crystal orientation. The objective is to explore how to control the structured dimensions based on atomic scale removal. First, the formation model of the etched structure was established in relation to thermal oxidation and graphitization, etc. Then, experiments were conducted to compare the structure size of the natural crystal surface. Finally, the etched structure dimension on the substrate was theoretically analyzed and experimentally characterized. It is shown that the dimension of etched structures depends on the rate of C atoms escaping layer by layer as CO/CO2 molecules with graphitization. The oxidative etching rate shows an increasing change in temperature. The degree of graphitization is enhanced as it approaches the (111) surface. At the macro scale, the structured size is subject to crystal orientation, environmental temperature, and catalysis. As a result, the micro- and nano-scale structures of the diamond substrate may be transferred to each other by the etching along crystal orientation.