HiPIMS-CVD Hybrid Process for Advanced Functional Coatings: Proof of concept

磁控溅射是一种物理气相沉积（PVD）工艺，广泛应用于工业中，用于沉积多种应用的功能涂层。虽然该方法能够存款各种各样的功能材料，包括在复杂的多层堆叠中的许多氧化物、氮化物和金属，在大面积上具有异常的均匀性，但是沉积速率相对较低，使得某些材料或产品的沉积不经济。此外，仍然存在一些商业上重要的材料，例如氧化铝，其可导致严重的加工不稳定性（即，电弧、阳极表面的损失、负离子的产生等），这限制了它们的使用。等离子体增强化学气相沉积（PECVD）是一种竞争工艺，其中气态前体通过由来自等离子体的高能粒子驱动的反应在基底上形成固体沉积物。PECVD工艺通常具有非常高的沉积速率、高一致性和低粗糙度的优点，但是在可沉积的叠层的材料范围和复杂性方面主要受到可用前体的限制。为了降低产品成本和提高性能，需要提高溅射工艺的速率和（在适用的情况下）稳定性，并且类似地需要提高/扩展PECVD工艺的材料选择和均匀性，以开辟新的应用。实现这些目标的另一种方法是同时将这些技术联合收割机结合起来。因此，该学术/工业合作项目旨在开发新的混合沉积工艺，将最新的磁控溅射技术与PECVD技术相结合，用于增强功能薄膜的高速沉积，能够扩大规模并集成到现有的大面积在线沉积设施中，以提供新的改进生产路线，理想情况下在低温下。这里采用的创新方法将是使用HiPIMS（高功率脉冲磁控溅射）功率输送模式来驱动磁控管和CVD工艺。这是HiPIMS首次在这种环境中使用，该提案旨在作为“概念验证”项目。HIPIMS涉及在短时间内向磁控管溅射阴极施加非常大的功率脉冲。这些强脉冲产生高等离子体密度，导致溅射物质的高度电离。然后可以通过改变磁控管的磁场强度来控制涂覆材料到基底的通量。因此，磁性阵列的调节允许控制溅射到生长的CVD膜的金属掺杂剂的通量的手段，同时仍然在相同的压力和时间平均功率下操作，并且因此仍然在处理区中保持相同的等离子体密度。因此，该项目的主要成果将是开发一种合成功能膜的新方法。该方法将通过仔细选择的与工业相关的功能膜的沉积和沉积过程的表征来验证。

Magnetron sputtering is a physical vapour deposition (PVD) process extensively used in industry for the deposition of functional coatings for many applications. Although the process is able to deposit a wide range of functional materials including many oxides, nitrides and metals in complex multi-layer stacks with exceptional uniformity over large areas, deposition rates are relatively low, making the deposition of certain materials or products uneconomical. In addition, there are still some commercially important materials, such as aluminium oxide, which can cause severe processing instabilities (i.e. arcing, loss of anode surfaces, creation of negative ions, etc.), which restricts their usage. Plasma enhanced chemical vapour deposition (PECVD) is a competing process in which gaseous precursors form solid deposits on the substrate through reactions driven by energetic particles from the plasma. PECVD processes generally have the advantage of very high deposition rates, high conformity and low roughness, but are limited, largely by the available precursors, in the range of materials and complexity of the stacks that can be deposited. There are also limitations in uniformity over large area substrates.In order to reduce product cost and improve performance, there is a demand to improve upon the rate and, where applicable, the stability of the sputtering process and a similar demand for improving/expanding the material choice and uniformity of the PECVD process to open up new applications. An alternative means of achieving these goals is to combine the technologies simultaneously. This academic/industrial collaborative project is designed, therefore, to develop new hybrid deposition processes, combining the latest magnetron sputtering technologies with PECVD technologies for the high rate deposition of enhanced functional films, which are capable of scale-up and integration into existing large area inline deposition facilities to provide a new improved route to production, ideally at low temperature. The innovative approach taken here will be to use the HiPIMS (high power impulse magnetron sputtering) power delivery mode to drive both the magnetron and the CVD process. This is the first time that HiPIMS will have been used in this environment and this proposal is designed to act as a 'proof of concept' project. HIPIMS involves the application of very large power pulses to magnetron sputter cathodes for short periods. These intense pulses create high plasma densities, leading to a high degree of ionization of the sputtered species. The flux of coating material to the substrate can then be controlled by varying the magnetic field strength of the magnetron. Thus, adjustment of the magnetic array allows a means of controlling the flux of sputtered metal dopant to the growing CVD film, whilst still operating at the same pressure and time averaged power and, therefore, still maintaining the same plasma density in the process zone. The primary deliverable from this project will, therefore, be the development of a new method for the synthesis of functional films. This method will be validated through the deposition of carefully selected functional films relevant to industry and the characterisation of the deposition process.