Selbst- und Fremddiffusion in Siliziumkarbid zur Charakterisierung der atomaren Eigenpunktdefekte in Siliziumkarbid

该建议旨在确定碳化硅中的本征点缺陷的性质，这些缺陷对这种宽禁带半导体中的扩散过程非常重要。为此，我们将使用可植入波恩同位素分离器设施的几个放射性杂质探测原子。合适的探测原子是7Be和35S，它们结合了良好的放射性衰变特性和预期的间隙-置换扩散机制。这一预期是基于文献中发现的关于碳化硅的数据，以及与S在硅中很好地描述的特征的类比。在广泛的温度范围内扩散退火后将测量浓度-深度分布。对轮廓的详细数值分析应导致确定所涉及的空位或自间隙的扩散机制和输运性质。在有利的情况下，还获得了关于点缺陷电荷态及其对自扩散的贡献的信息。一个雄心勃勃的目标是希望同时提取Si和C亚晶格的点缺陷数据。我们期望，该项目的结果将对目前对具有重要技术意义的半导体碳化硅的扩散过程和点缺陷行为的了解不足提供实质性的贡献。

The proposal aims at determining properties of native point defects in SiC that are important for diffusion processes in this wide-bandgap semiconductor. For this purpose we will use several radioactive impurity probe atoms that can be implanted at the Bonn isotope separator facility. Suitable probe atoms are 7Be and 35S which combine favourable radioactive decay properties with an expected interstitial-substitutional diffusion mechanism in SiC. This expectation is based on the data found for SiC:Be in the literature and on analogies with the well-characterized features of S in silicon.Concentration-depth profiles will be measured after diffusion annealing over a wide range of temperatures. Detailed numerical analysis of the profiles should lead to the identification of the diffusion mechanism and the transport properties of the vacancies or self-interstitials involved. In favourable cases information about the point-defect charge states and their contribution to self-diffusion in SiC is obtained as well. An ambitious goal is given by the wish to extract point-defect data both for the Si and the C sublattice. We expect that the results of this project will provide a substantial contribution to the present poor understanding of diffusion processes and point-defect behaviour in the technologically important semiconductor SiC.