Modeling of metastable phase formation diagrams for sputtered thin films

溅射薄膜亚稳态相形成图的建模

• 批准号: 314558433
• 负责人: Professor Jochen M. Schneider, Ph.D., since 11/2017
• 金额: --
• 依托单位: Lehrstuhl für Werkstoffchemie (MCh)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/314558433?language=en
• 关键词: Modeling; metastable; phase; formation; diagrams

Due to kinetically limited vapor phase condensation processes, metastable phases are commonly obtained during synthesis of thin films, which makes prediction of their structures and properties rather demanding. By applying theoretical means like CALPHAD and ab initio calculations, phase stability of the thin film systems has extensively been investigated. As a typical example, the metastable solubility limits of AlN in c-Ti1-xAlxN thin films are well described using these means. However, for efficient thin film materials design the knowledge of metastable phase formation diagrams is essential. To date, modeling of metastable phase formation diagrams for sputtered thin films has not been reported.In preliminary work a modelling strategy to predict metastable phase formation diagrams (containing Bcc and Fcc phases) for the immiscible Cu-W and Cu-V systems has been proposed and the calculations agree well with experimental data.In the here proposed project, the industrially relevant systems Ti-Al-N and Zr-Al-N, focusing on the TiN-AlN and ZrN-AlN pseudo-binary sections, will be studied using a correlative experimental and theoretical approach.Stoichoimetric nitride thin films (i.e., Ti1-xAlxN1 and Zr1-xAlxN1) will be synthesized using a combinatorial approach to obtain the metastable phase formation data. Ab initio calculations will be used to acquire enthalpy of formation and surface diffusion activation barriers of the Ti1-xAlxN1 and Zr1-xAlxN1 phases. Thermodynamic descriptions of the ternary Ti-Al-N and Zr-Al-N systems will be obtained using the CALPHAD approach.The proposed methodology will be validated by modeling the metastable phase formation diagrams for the TiN-AlN and ZrN-AlN thin films. A comprehensive strategy will be obtained to study the thermodynamics and kinetics of the sputtered thin films aiming to formulate metastable phase formation diagrams (non-equilibrium) for sputtered thin films, as well as phase diagrams (equilibrium) for the entire material system. The proposed strategy is expected to be applicable to other systems, allowing for understanding the composition-structure-property relationships for thin films more efficiently and hence provide a solid basis for the future design of thin film materials.

由于气相冷凝过程受动力学限制，薄膜合成过程中通常会获得亚稳态相，这使得对其结构和性能的预测要求相当高。通过应用 CALPHAD 和从头计算等理论手段，薄膜系统的相稳定性得到了广泛的研究。作为一个典型的例子，使用这些方法很好地描述了 c-Ti1-xAlxN 薄膜中 AlN 的亚稳态溶解度极限。然而，对于有效的薄膜材料设计，亚稳态相形成图的知识至关重要。迄今为止，溅射薄膜亚稳态相形成图的建模尚未见报道。在初步工作中，提出了一种预测不混溶 Cu-W 和 Cu-V 体系亚稳态相形成图（包含 Bcc 和 Fcc 相）的建模策略，并且计算结果与实验数据吻合良好。在此提出的项目中，工业相关体系 Ti-Al-N 和 Zr-Al-N，重点关注 TiN-AlN 和 ZrN-AlN 伪二元截面将使用相关的实验和理论方法进行研究。化学计量氮化物薄膜（即 Ti1-xAlxN1 和 Zr1-xAlxN1）将使用组合方法合成以获得亚稳态相形成数据。从头计算将用于获取 Ti1-xAlxN1 和 Zr1-xAlxN1 相的形成焓和表面扩散活化势垒。三元 Ti-Al-N 和 Zr-Al-N 系统的热力学描述将使用 CALPHAD 方法获得。所提出的方法将通过对 TiN-AlN 和 ZrN-AlN 薄膜的亚稳态相形成图进行建模来验证。将获得研究溅射薄膜的热力学和动力学的综合策略，旨在制定溅射薄膜的亚稳态相形成图（非平衡）以及整个材料系统的相图（平衡）。该策略有望适用于其他系统，从而更有效地理解薄膜的成分-结构-性能关系，从而为未来薄膜材料的设计提供坚实的基础。