## 1 Introduction  
Semiconductor chip manufacturers use in their _in-situ_ processes a variety of gases to pattern silicon wafers and to reach a rapid cleaning of chemical vapor deposition (CVD) tool chambers. To maintain a high throughput during the thin film deposition processes, it is essential to optimize the cleaning step in a way to remove perfectly the residual thin films deposited on the CVD chamber inner wall without generating any particles. The presence of particles inside the CVD chamber will lead to a degradation of the device performance.  
Under industrial process conditions, non-negligible amounts of unreacted fluorinated gases ranging between 10-80% are released into the atmosphere. Unfortunately, they are considered as greenhouse gases with a high global warming potential [1]. Greenhouse gases in the upper atmosphere avoid releasing the infrared radiation to the universe by reflecting it backwards to the earth. The global warming potential (GWP) of a gas is generally measured in a 100-year time horizon and expressed in CO\({}_{2}\) equivalents. The GWP value depends on the lifetime of the gas in the atmosphere and its ability to absorb radiation.  
In the last climate conference in Paris, which took place on 2015, a binding and universal climate target was set [2]. An agreement to limit the temperature increase to a maximum of 2 \({}^{\circ}\)C by 2100 was made.  
Most of the gases employed by the semiconductor industry are CF\({}_{4}\), C\({}_{2}\)F\({}_{6}\), and C\({}_{3}\)F\({}_{8}\), which are named perfluorocarbons, nitrogen trifluoride NF\({}_{3}\), and sulfur hexafluoride SF6. According to the World Semiconductor Council, in 2013 the semiconductor industry used 7512 t of NF\({}_{3}\), 1133 t of CF\({}_{4}\), and 708 t of C\({}_{2}\)F\({}_{6}\) on a global basis [3]. Approximately 72% of all semiconductor industry gaseous emissions are caused from these three gases. Although the semiconductor industry is only a small contributor to global warming, several fluorinated gases with a high global warming potential (GWP) are intensively used, and large quantities of Perfluorinated compounds (PFCs) are emitted. NF\({}_{3}\) is the mostly used gas with a GWP of 17,200, followed by C\({}_{2}\)F\({}_{6}\) and CF\({}_{4}\) with GWPs of 1200 and 7390, respectively [4]. The main applications of these gases are to remove the residual films remaining inside deposition chambers after a plasma-enhanced chemical vapor deposition process (PECVD). The most important materials to remove are dielectric layers such as silicon oxides (SiO\({}_{2}\)), carbon-containing silicon oxides, silicon nitrides (Si3N4), and, to a certain extent, conducting films such as doped polysilicon and silicide layers.  
Both Fraunhofer EMFT (Research Institution for Microsystems and Solid State Technologies) and Solvay have joined their efforts in a research program to find safe alternative gases to be used in the manufacturing processes for ensuring climate safety. Our goal is focused on finding an adequate gas for the semiconductor industry, which could be easily integrated to the existing CVD equipment so that buying any new systems or including important modifications to the onsite hardware are avoided. This means that the proposed approach has to be, on the one hand, a cost-effective solution for industrial companies, and on the other hand, reduce the amount of the used greenhouse gases. Here, we propose a fluorine gas mixture as an environmental-friendly gas for the CVD cleaning processes to replace C\({}_{2}\)F\({}_{6}\) and NF\({}_{3}\) gases in the near future.  
In this paper, we report a comparison study between cleaning processes using C\({}_{2}\)F\({}_{6}\), NF\({}_{3}\), and a fluorine gas mixture (F\({}_{2}\)-gas mixture) performed in a 200-mm wafer-size CVD tool for SiO\({}_{2}\) thin-layer deposition [5; 6]. The process chamber ran with the new cleaning chemistry and was inspected on a regular basis during the period of this study in order to detect any equipment degradation related to using the new gas mixture.