Reactive Ion Etcher for cryo processes

康斯坦茨大学纳米结构中心实验室（纳米实验室）申请使用反应离子蚀刻设备，从2001年起将取代现有设备，并将扩大纳米实验室的可能性。现有的设备仅用于非常特殊和非常各向同性的蚀刻工艺，因为它针对高工艺压力下的工作进行了优化。各向异性蚀刻轮廓不能用现有设备实现。即使在另一个现有的、稍微年轻的工厂中，使用氟化学的各向异性蚀刻轮廓也仅在非常有限的程度上是可能的，并且不能改造其他工艺类型。除了各向同性蚀刻，新设施还应允许高度各向异性蚀刻工艺。这些蚀刻工艺对于纳米机械项目和硅基光波导的生产特别重要。对于这些各向异性工艺，将使用聚合物成型工艺气体，使侧壁钝化。除了通常的射频源外，新设施还将配备ICP（电感耦合等离子体）源。ICP的使用使得即使在非常低的工艺压力下也可以保证气体中具有高离子和自由基密度的稳定等离子体。即将到来的研究项目的另一个重要优势是在蚀刻过程中等离子体密度和离子能量（直流偏压）的独立可调性，这是由ICP提供的。这使得可以在低离子能量下进行蚀刻，具有非常少的缺陷和非常高的选择性，这也提供了对蚀刻轮廓的最佳控制。这是一种绕过专利的、极其耗时的“Bosch工艺”的技术，该工艺是为高度各向异性的工艺而建立的。新工厂将专门使用氟气，现有工厂将来将专门用于氯工艺，以实现工艺的必要再现性，并能够更有效地使用设备。通过这两个工厂，可以对各种材料进行非常精确的干法蚀刻，以满足物理和化学领域的广泛用户。高精度的结构生产对于项目的实施是必要的。为了确保这一点，有必要对相关工艺参数进行最大限度的控制。因此，工厂的设备应包括衬底电极的温度控制，以确保结果的再现性。可以在宽的温度范围内控制的衬底电极也可以显著地扩展系统的应用范围，因为可以通过温度控制化学反应性。激光干涉仪将允许原位监测蚀刻深度。此外，系统应配备干泵，以保证无油和清洁工作。

The central nanostructure laboratory of the University of Konstanz (nano.lab) applies for reactive ion etching facility, which will replace an existing device from 2001 and will expand the possibilities of the nano.lab. The existing plant is only used for very special and very isotropic etching processes, as it is optimized for working under high process pressures. Anisotropic etching profiles cannot be realized with the existing equipment. Even in another existing, somewhat younger plant, anisotropic etching profiles using fluorine chemistry are only possible to a very limited extent and further process types cannot be retrofitted. In addition to isotropic etching, the new facility should also allow highly anisotropic etching processes. These etching processes are particularly important for projects in nanomechanics and the production of silicon-based optical waveguides. For these anisotropic processes, polymer-forming process gases are to be used, which enable the sidewalls to be passivated.In addition to the usual radiofrequency source the new facility will be equipped with an ICP (Inductively Coupled Plasma) source. The use of an ICP makes it possible to guarantee a stable plasma with a high density of ions and radicals in the gas even at very low process pressures. Another important advantage for the upcoming research projects is the independent adjustability of plasma density and ion energy (DC bias) during the etching process, which is given by the ICP. This makes it possible to etch at low ion energies with very few defects and very selectively, which also provides optimal control of the etching profiles. This is a technique that bypasses the patented and extremely time-consuming "Bosch process", which has been established for highly anisotropic processes.The new plant is to be operated exclusively with fluorine gases, and the existing plant is to be used exclusively for chlorine processes in the future in order to achieve the necessary reproducibility of the processes and to be able to use the equipment more efficiently. With these two plants, a very wide range of materials can be dry-etched very precisely for a wide range of users in the fields of physics and chemistry.A high degree of precision in the production of the structures is necessary for the implementation of the projects. To ensure this, it is necessary to have maximum control over the relevant process parameters. The equipment of the plant should therefore include a temperature control of the substrate electrode to ensure reproducibility of the results. A substrate electrode that can be controlled over a wide temperature range can also significantly extend the range of applications of the system, since the chemical reactivity can be controlled via the temperature. A laser interferometer will allow in-situ monitoring of the etching depth. In addition, the system should be equipped with dry pumps to guarantee oil-free and clean work.