2024-12-02 オーストラリア連邦・マッコーリー大学
＜関連情報＞
- https://www.mq.edu.au/faculty-of-science-and-engineering/news/news/new-laser-technique-achieves-atomic-scale-precision-on-diamond-surfaces
- https://www.sciencedirect.com/science/article/pii/S0169433224025327?via%3Dihub
サブ単層レーザーエッチングが(100)ダイヤモンド表面の化学的および電気的特性に及ぼす影響 The effects of sub-monolayer laser etching on the chemical and electrical properties of the (100) diamond surface
Mojtaba Moshkani,Michael W. Geis,James E. Downes,Richard P. Mildren
Applied Surface Science Available online: 20 November 2024
DOI:https://doi.org/10.1016/j.apsusc.2024.161816
Graphical abstract
Highlights
- Sub-monolayer etch doses of UV alter the top layer chemistry and surface electrical properties.
- UV laser doses increase the surface conductivity by 5-7 times.
- The UV effect may include rearrangement of the surface to align step edges or make in more {111}-like.
Abstract
Tailoring the surface chemistry of diamond is critical to a range of applications from quantum science to electronics. It has been recently shown that dosing the diamond surface with pulsed UV light at fluences below the ablation threshold provides a practical method for precision etching of the surface. Here, we track the evolution of the surface chemistry and its electrical properties as a function of dose using x-ray surface analysis, Hall and resistance measurements. It is found that the surface properties evolve rapidly, even for doses that correspond to removal of less than 5% of the top carbon monolayer and fluences less than 1 J/cm<?XML:NAMESPACE PREFIX = “[default] http://www.w3.org/1998/Math/MathML” NS = “http://www.w3.org/1998/Math/MathML” />2. As well altering XPS-measured surface populations, sub-monolayer etch doses lower the valence band by up to 0.2 eV, and produce a permanent increase in the conductivity of the hydrogen terminated surface by up to 7 times. Similar enhancements in conductivity are obtained for doses that remove up to 1600 ML. The results provide guidance for manipulating diamond surface chemistry by UV laser etching and introduce a promising method for enhancing the performance of diamond devices such as field-effect transistors.
