Université de Lyon, Université Claude Bernard Lyon1, CNRS, Laboratoire des Multimatériaux et Interfaces (LMI, UMR 5615), 43 bd du 11 Novembre 1918, F-69622 Villeurbanne, France.
Université Grenoble Alpes, CNRS, LMGP, F-38000 Grenoble, France.
Sci Rep. 2017 Feb 17;7:43069. doi: 10.1038/srep43069.
Nitrogen doping of 4H-SiC during vapor phase epitaxy is still lacking of a general model explaining the apparently contradictory trends obtained by different teams. In this paper, the evolutions of nitrogen incorporation (on both polar Si and C faces) as a function of the main growth parameters (C/Si ratio, temperature, pressure and growth rate) are reviewed and explained using a model based on surface exchanges between the gas phase and the uppermost 4H-SiC atomic layers. In this model, N incorporation is driven mainly by the transient formation of C vacancies, due to H etching, at the surface or near the surface. It is shown that all the growth parameters are influencing the probability of C vacancies formation in a similar manner as they do for N incorporation. The surface exchange model proposes a new framework for explaining the experimental results even beyond the commonly accepted reactor type dependency.
在气相外延过程中对 4H-SiC 进行氮掺杂仍然缺乏一个通用模型来解释不同团队得到的明显矛盾的趋势。本文综述了氮掺入（在 Si 和 C 两个极面上）随主要生长参数（C/Si 比、温度、压力和生长速率）的变化，并使用基于气相与最上层 4H-SiC 原子层之间的表面交换的模型进行了解释。在该模型中，N 的掺入主要是由 H 刻蚀在表面或表面附近形成的 C 空位的瞬时形成驱动的。结果表明，所有生长参数都以与 N 掺入相似的方式影响 C 空位形成的概率。表面交换模型提出了一个新的框架来解释实验结果，甚至超出了通常接受的反应堆类型依赖性。
