New strategy for the deposition of metals by CVD and ALD: mechanistic and kinetic investigation for the growth of cobalt as model system

比勒费尔德团队最近开发了一种无氢金属化学气相沉积（CVD）方法，该方法使用脉冲喷雾蒸发（PSE）在醇中提供简单且可商购的金属有机前体。这种方法被证明是成功的生长的一些过渡金属是相关的催化，光子，磁性和电子应用。除了众多的技术优势外，它还具有在液体注入原子层沉积（LI-ALD）机制中操作的能力。尽管技术实现简单，但无污染的高质量薄膜的生长取决于前体、表面和醇之间的复杂相互作用，而这又取决于各种参数。因此，为了充分利用这一新方法的潜力，必须彻底查明和了解所有相关的基本机制。这一目标将通过项目合作伙伴之间的密切合作来实现，这些合作伙伴具有互补的专业知识，可以将宏观生长行为与分子尺度上的过程联系起来。在不同工艺条件下的化学和动力学的详细原位表征的结果将与超高真空（UHV）条件下研究的表面化学相关。作为一个模型系统，Co膜的生长将进行研究，因为在前期工作中观察到的表现出丰富的化学。通过这种方式，将为未来的工艺升级和优化奠定基础，以实现纯金属薄膜生长的高效和高选择性方法。

The Bielefeld team has recently developed a hydrogen-free approach to metal-chemical vapor deposition (CVD), which uses pulsed-spray evaporation (PSE) delivery of simple and commercially available metal-organic precursors in alcohols. This approach was demonstrated to be successful for the growth of a number of transition metals that are relevant in catalytic, photonic, magnetic and electronic applications. Besides the numerous technical advantages, it has the capability to operate in the liquid-injection atomic layer deposition (LI-ALD) regime as well. Notwithstanding the simplicity of the technical realization, the growth of high-quality thin films without contaminations is dependent on the complex interplay between the precursor, the surface and the alcohol which in turn depends on a variety of parameters. Thus, to fully exploit the potential of this new approach, a thorough identification and understanding of all relevant fundamental mechanisms is essential. This goal will be achieved by an intense collaboration between the project partners with complementary expertise which allow connecting the macroscopic growth behavior with the processes on the molecular scale. Results of a detailed in-situ characterization of the chemistry and the kinetics under different process conditions will be correlated with the surface chemistry investigated under ultra-high vacuum (UHV) conditions. As a model system, the growth of Co films will be studied because of the exhibited rich chemistry observed in preliminary work. In this way, the foundations shall be laid for future upscaling and optimization of the processes towards efficient and highly selective methods for the growth of pure metallic thin films.