Fabrication process and first charactesisation of novel silicon-based microplasma reactors
Résumé
To answer new challenges such as the development of original deposition methods, a new design of silicon-based microplasma reactors with a through silicon via (TSV) was developed. Based on a previous version of Micro Hallow Cathode Discharge (MHCD) [1], the novelty of this work lies in the backside processing of the microreactor to open the cavity and create a gas flow in the hole. This was performed using the patented STiGer etching process developed at the GREMI laboratory [2] to obtain an anisotropic 300 μm deep TSV (Fig.1 a)). Electrical and optical diagnostics were conducted in helium microplasma for different pressures. So far, the MHCD with a TSV proved themselves more durable and capable of sustaining higher current than the previous version [1]. Although, a so-called “self-pulsing regime” [3] is observed below a certain current threshold Fig.1 b), a steady glow discharge following a normal regime is obtained at both high and atmospheric pressure. This is because the TSV enhances considerably the size of the cathode, which gives more surface to the plasma to expand. Electrical and spectroscopic characterizations have been carried out and compared to the results obtained in a closed cavity. Figure 1: a) Design of the microreactor, b) V-I characteristics in He with a 1 MΩ ballast resistor. Acknowledgement: This work is supported through the ANR project PlasBoNG. (ANR-20-CE09-0003). The CERTeM 2020 platform has provided most of the equipment necessary to prepare the microreactors. [1] R. Michaud et al., Plasma Sources Sci. Technol 27, 025005, (2018) [2] T. Tillocher et al., J. Micromech. Microeng 21, 085005, (2011) [3] V. F e l i x et al., Plasma Sources Sci. Technol 25, 025021, (2016)