High-energy laser-assisted hybrid magnetron sputtering for enhanced thin film deposition

制造业仍然是工业的关键驱动力，在非常具体应用的材料和设备的先进制造方面做出了巨大努力。其中许多依赖于或可以显著增强使用纳米沉积/涂层，如脉冲激光沉积或磁控溅射。这两种方法都有特定的优点和缺点，例如，控制成分或均匀覆盖的面积。虽然已经有人提出了实施混合工艺的建议，但还没有一个专门的工艺来提供稳定和适应性的操作范围，从而获得两种技术的优势。我们之前已经证明了在磁控溅射靶连续工作时，超过烧蚀阈值的激光脉冲对靶的影响。研究表明，与ns激光相比，fs或ps激光脉冲的烧蚀阈值显著降低，并且环境压力对沉积薄膜的质量起着重要作用。该提案的目的是在室温下使用混合方法沉积三种专用薄膜系统，以产生非常特定的结构和大的涂层区域。这些薄膜具有很强的技术兴趣，同时将沉积过程的不同方面推向了极端。我们计划合成（Hf, Zr）O2隧道结，用于需要将厚度控制在几纳米范围内的神经形态计算。然后，我们建议羟基磷灰石，一种生物相容性材料，需要大的沉积速率和大面积覆盖，需要专用的介孔结构，最终是双钙钛矿Bi2FeCrO6，具有可调的带隙，用于体光伏效应，依赖于在非常窄的工艺窗口中控制磁有序。通过与我们的工业合作伙伴合作，并使用独特的高功率激光基础设施ALLS，我们希望在令人鼓舞的初步结果的基础上，证明我们的新型混合方法不仅提供稳定的中间生长条件，而且具有极好的潜力，可以根据各种材料，沉积速率和区域微调工艺参数。

The manufacturing sector remains a key driver in industry, with a strong effort in the advanced manufacturing of materials and devices for very specific applications. Many of those rely on or can significantly be enhanced using nanometric deposition/coating as provided by e.g. pulse laser deposition or magnetron sputtering. Both methods have specific benefits and demerits related to e.g. the control of composition or the area for homogeneous coverage. While there have been proposals to implement hybrid processes, a dedicated process to provide a stable and adaptable range of operation accessing the benefits of both techniques, is yet to be demonstrated. We have previously demonstrated the effect of laser pulses with fluencies exceeding the ablation threshold on the magnetron sputtering target, while it operates continuously. It has been shown that with fs, or ps laser pulses, the ablation threshold decreases very significantly compared to ns lasers and that the ambient pressure plays a significant role for the quality of deposited films. The aim of this proposal is the deposition of three dedicated thin films systems near room temperature using the hybrid approach for generating very specific structures and large coating areas. These thin films have strong technological interest while pushing different aspects of the deposition process to extremes. We plan to synthesize (Hf, Zr)O2 tunnel junctions, for neuromorphic computing that requires excellent control of the thickness in the range of a few nanometers. We then suggest hydroxyapatite, a biocompatible material for which large deposition rates and large area coverage are desirable with a need for a dedicated mesoscopic structure and ultimately the double perovskite Bi2FeCrO6, with a tunable bandgap for the bulk photovoltaic effect that relies on the control of magnetic ordering in a very narrow process window. In collaboration with our industrial partners and using the unique high-power laser infrastructure ALLS, we expect to demonstrate, based on encouraging preliminary results, that the our novel hybrid approach does not only provide stable intermediate growth conditions but an excellent potential to fine-tune the process parameters to a large variety of materials, deposition rates and areas.