Microplasmas have gained in popularity throughout the years for their significant potential for technological innovations and for their exceptional properties that make them unique and different from larger plasma sources [1]. For instance, they can operate with a remarcably high power density, up to 107 W·m-3. Indeed, micro-plasmas have revealed themselves to be great source of different applications. For example, they can be used for depollution purposes, for gas detection or in fabrication processes, as well as for etching or deposition of materials [2]. One important aspect that needs to be considered is the fabrication process of the microreactors capable of sustaining such a high energy density in the confined plasma source. Fabrication processes and methods vary depending on the source. From the historical structures, which are made by drilling a hole between two metallic electrodes separated by a dielectric layer, to more complex designs, which demand novel fabrication techniques, like the one that will be discussed here. MHCD (Micro Hollow Cathode Discharge) type microplasma sources on silicon were first introduced by Eden et al,[3] at the beginning of the century. They were micro-machined using MEMS (Micro Electro Mechanical Systems) fabrication methods, which allowed a larger flexibility in the geometry of the reactors. Our designs, called MHCD-TSV (for Through Silicon Via), are also manufactured using these techniques. As mentioned, the motivation is to be able to go through the wafer that is here 400 μm thick. To do that we performs UV-Lithography to imprint patterns on the front and the back of the wafer. Once we have our patterns on the wafer, we use ICP-RIE procedures to etch the dielectric layer and the isotropic cavities. The electrodes are then deposited on the surface of the dielectric layer and at the bottom of the cavities using magnetron sputtering. This is part of the front side processing. The main technological barrier in our case is to perform adeep an-isotropic etching of the silicon in order to obtain the TSV shown in Fig.1. To achieve this, we used an etching process developed at the GREMI laboratory called the STiGer process [4]. This method, carried out on the backside, alternates etching and passivation steps at cryogenic temperatures (typically -100°C), which allows to an-isotropically etch 300 μm deep holes in silicon. In total, the fabrication process for those type of microplasma reactors takes 19 steps and it can take up to a week to obtain a wafer completed with microreactors. When compared to closed cavity shaped microplasma reactors [5], MHCD-TSV sustain higher current values. They also produce high electron density plasmas (ranging from 1013 to 1016 cm-3). [1] K. H. Schoenbach and K. Becker, “20 years of microplasma research: a status report,” Eur. Phys. J. D, 70, 2, (2016). [2] H. Kabbara et al., “A microplasma process for hexagonal boron nitride thin film synthesis,” Appl. Phys. Lett., 116, 17, (2020). [3] J. G. Eden et al., “Microplasma devices fabricated in silicon, ceramic, and metal/polymer structures: arrays, emitters and photodetectors,” J. Phys. D: Appl. Phys., 36, 23, (2003). [4] T. Tillocher et al., “Optimization of submicron deep trench profiles with the STiGer cryoetching process: reduction of defects,” J. Micromech. Microeng., 21, 8, (2011). [5] R. Michaud et al., “Direct current microhollow cathode discharges on silicon devices operating in argon and helium,” Plasma Sources Sci. Technol., 27, 2, (2018).