HF vapor etching machine

纳米结构的制备在新型量子技术的研究中起着核心作用，特别是在量子信息处理和量子传感器系统的实现中。在这种情况下，通常需要从样品中去除二氧化硅和/或氮化硅而不损坏其它结构（例如，由硅、金、铜、碳化硅或氮化硅制成）。这可以通过在氢氟酸（HF）中的化学蚀刻来实现。然而，使用液体HF具有显著的缺点：一方面，对频繁使用的样品材料的选择性低并且不能调节。另一方面，在从酸中取出样品和随后的干燥过程中，由于表面张力而产生的力通常会破坏较大的纳米结构，从而使其无法制造。如果用HF蒸汽代替液体酸，这两个关键缺点可以避免。在所提出的装置中，HF不仅以受控的方式蒸发，而且另外，通过精确控制工艺气体的温度、压力和组成来实现对蚀刻速率和相对于其它样品材料的选择性的精确控制。此外，还有其他优点：降低了溶液中悬浮颗粒污染样品的风险，这显著提高了较大纳米结构的产率。此外，由于避免了处理液体HF酸和与之相关的显著健康风险，因此安全性增加。最后，具有氢原子的无氧化物表面终止物在硅样品上保留数分钟，这是进一步工艺步骤（例如ALD、CVD、MBE）所需的。总之，使用RF气相蚀刻装置，例如本提案所针对的装置，将在纳米结构量子系统和材料的制造中提供显著的优点。因此，相应的设备目前面临着很高的国际需求。购买相应的机器将确保Garching校园在生产复杂纳米结构方面保持国际竞争力。

The fabrication of nanostructures plays a central role in the investigation of novel quantum technologies, especially in the realization of systems for quantum information processing and quantum sensors. In this context, it is often necessary to remove silicon dioxide and/or silicon nitride from samples without damaging other structures (e.g., made of silicon, gold, copper, silicon carbide, or silicon nitride). This can be achieved by chemical etching in hydrofluoric acid (HF). However, the use of liquid HF has significant disadvantages: On the one hand, the selectivity towards frequently used sample materials is low and cannot be adjusted. On the other hand, forces due to surface tension occur during removal of the sample from the acid and during subsequent drying, which often destroy larger nanostructures and thus make their fabrication impossible. These two crucial disadvantages can be avoided if HF vapor is used instead of liquid acid. In the porposed device, HF is not only vaporized in a controlled manner, but in addition, precise control of the etch rate and selectivity over other sample materials is achieved by precisely controlling the temperature, pressure and composition of the process gases. In addition, there are other advantages: The risk of sample contamination from suspended particles in solution is reduced, which significantly improves the yield for larger nanostructures. In addition, safety is increased because handling liquid HF acid and the significant health risks associated with it are avoided. Finally, an oxide-free surface termination with hydrogen atoms remains on silicon samples for several minutes, which is required for further process steps (e.g. ALD, CVD, MBE). In summary, the use of an RF vapor etching device, such as the one targeted by this proposal, will provide significant advantages in the fabrication of nanostructured quantum systems and materials. For this reason, corresponding devices are currently facing a high international demand. Purchasing of a corresponding machine would ensure that the Garching campus remains internationally competitive in the production of complex nanostructures.