Concepts and mechanisms of dislocation density reduction in heteroepitaxial diamond

异质外延金刚石位错密度降低的概念和机制

• 批准号: 453637298
• 负责人: Dr. Matthias Schreck
• 金额: --
• 依托单位: Lehrstuhl für Experimentalphysik IV
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/453637298?language=en
• 关键词: Concepts; mechanisms; dislocation; density; reduction

Heteroepitaxial diamond can be grown by chemical vapor deposition (CVD) on Ir/YSZ/Si in wafer size. Under appropriate process conditions, the initial dislocation density of > 10^10 cm^-2 drops to values of ~ 7×10^6 cm^-2 at thicknesses of 2 - 3 mm. For a successful application of the material in the fields of high power electronics, quantum sensing or optics a further reduction is desirable. In the present project we will explore several alternative concepts like epitaxial lateral overgrowth (ELO) using different mask materials, geometries, as well as mask-less approaches or the recently published Metal Assisted Termination (MAT) method in order to evaluate their efficiency and the underlying mechanisms of dislocation density reduction. Pseudosubstrates with defect densities of ~10^7 cm^-2 synthesized by heteroepitaxy will be applied to deposit masks, form structures or grow MAT layers before they are overgrown in a microwave plasma CVD process. Besides the simple but highly accurate etch pit counting method, characterization will include high resolution x-ray diffraction, Raman-, photoluminescence- and cathodoluminescence spectroscopy as well as transmission electron microscopy. Defect-reduced samples will be supplied to partners at accelerator facilities for the preparation of particle and radiation detectors and the analysis of their properties.

采用化学气相沉积（CVD）方法在Ir/YSZ/Si衬底上生长出了圆片尺寸的异质外延金刚石。在适当的工艺条件下，初始位错密度> 10^10 cm^-2，在厚度为2 ~ 3 mm时降至约7×10^6 cm^-2。为了使该材料成功应用于高功率电子学、量子传感或光学领域，需要进一步降低位错密度。在本项目中，我们将探索几种替代概念，如使用不同掩模材料，几何形状以及无掩模方法或最近发表的金属辅助终止（MAT）方法的外延横向过生长（ELO），以评估其效率和位错密度降低的潜在机制。通过异质外延合成的缺陷密度约为10^7 cm^-2的伪衬底将用于存款掩模、形成结构或在微波等离子体CVD工艺中过度生长MAT层之前生长MAT层。除了简单但高度准确的蚀坑计数方法，表征将包括高分辨率X射线衍射，拉曼，光致发光和阴极发光光谱以及透射电子显微镜。缺陷减少的样品将提供给加速器设施的合作伙伴，用于制备粒子和辐射探测器并分析其性能。