Dual Source Pulsed Plasmas for the Production of Ultra-High Performance Coatings

脉冲处理开创了表面工程技术的新时代。例如，脉冲磁控溅射已经改变了介电材料的沉积。脉冲处理的优点可以通过在衬底上应用中频脉冲DC功率来进一步利用。这种“双源”溅射模式使用一个脉冲功率源在靶的前面产生等离子体，并且使用第二个类似的源在衬底的前面激发等离子体。这使得能够以灵活和通用的方式独立于溅射条件来控制衬底处的沉积条件。这提供了一种新的和令人兴奋的手段来控制在薄膜沉积过程中传递到基底的能量，这是决定磁控溅射涂层的微观结构和性能的关键因素。到目前为止，这项技术在很大程度上被忽视了。因此，我们的目标是对这项技术进行首次详细研究，以期生产超高性能涂层，特别是针对干加工和干运转部件等应用，在减少使用碳氢化合物润滑剂的环境压力下，要求涂层具有目前技术难以提供的性能。我们将研究在增强和控制中使用双源排放在沉积期间入射到衬底上的离子与原子的比率以及在沉积之前的离子蚀刻工艺的有效性。然而，为了充分利用这种新技术的潜力，还需要对等离子体进行详细的测量。因此，这项研究也将导致在脉冲放电等离子体测量技术的进步。所获得的信息将使我们能够确定在目标和在基板上的驱动电压波形之间的相互关系和形成的多激发放电的性质，以及它们对薄膜生长的综合影响。

Pulsed processing has initiated a new era in surface engineering technologies. For example, pulsed magnetron sputtering has transformed the deposition of dielectric materials. The benefits of pulsed processing can be further capitalised on through the application of mid-frequency pulsed DC power at the substrate. This 'dual source' sputtering mode uses one pulsed power source to generate a plasma in front of the target and a second, similar, source to excite a plasma in front of the substrate. This enables the deposition conditions at the substrate to be controlled independent of the sputtering conditions in a flexible and versatile manner. This offers a new and exciting means of controlling the energy delivered to the substrate during film deposition, which is a critical factor in determining the microstructures and properties of magnetron sputtered coatings. To date, this technique has been largely overlooked. We aim, therefore, to perform the first detailed study of this technique, with a view to producing ultra-high performance coatings, particularly aimed at applications such as dry machining and dry-running components, where environmental pressures to reduce the use of hydrocarbon lubricants demand coatings with properties that present technologies are struggling to deliver.We will investigate the use of dual source discharges in the enhancement and control of the ion-to-atom ratio incident at the substrate during deposition and the effectiveness of the ion etch process prior to deposition. However, in order to exploit the full potential of this new technique, it will also be necessary to undertake detailed measurements of the plasma. Thus, this study will also lead to the advancement of plasma measurement techniques in pulsed discharges. The information gained will allow us to determine the interrelationships between the driving voltage waveforms at the targets and at the substrate and the nature of the multi-excited discharge that forms, and their combined impact on film growth.