摘要： GeSn, a group IV binary alloy, is currently of high interest. Its use is envisioned in two kinds of applications: (i) as a source/drain compressive stressor in order to boost the hole mobility in short gate length Ge channel p-type MOSFETs [1] and (ii) as a direct-band-gap material for Si photonics, provided that the Sn content is higher than 10%, typically [2]. However, the fabrication of GeSn-based components faces major technological issues. First of all, as the lattice mismatch between Sn and Ge is large (14%) and the solubility of Sn in Ge low at thermodynamic equilibrium (< 1%), specific conditions have to be used for the epitaxial growth of high Sn content GeSn layers. Moreover, the fabrication of efficient ohmic contacts to receive and deliver power and signals is challenging. Ni-stanogermanides are currently under investigation in order to benefit from low contact resistivity (Rc) and sheet resistance (Rsh) in GeSn-based devices. The surface preparation of such metastable alloys will then be an unavoidable step. Whatever the targeted application, wet cleaning is indeed mandatory to remove particles, organic materials, metallic impurities and native oxides from the surface. Literature data on GeSn surface preparation prior to metallization is currently scarce [3], [4]. Based on the existing knowledge on pure germanium, we will likely have to cope with a high dissolution in oxidant solutions (GeO2 dissolution in water) and unstable surface preparations (high reactivity upon air and oxygen exposure). Ex-situ wet cleanings will likely suffer from a fast native oxide regrowth on the GeSn surface. In-situ plasma treatments in a chamber connected to the metal deposition chamber itself, i.e. without any air break, should enable to get rid of that problem. In this work, after a characterization of the native oxide formed upon air exposure of Ge0.85Sn0.15 alloys, we investigate the impact of i) wet chemistries, ii) plasma treatments and iii) “wet + plasma” combinations on GeSn surface oxide removal.