| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | A. Rhallabi, Institut des Materiaux Jean Rouxel, France |
| Authors: | L. Lallement, Institut des Materiaux Jean Rouxel, France A. Rhallabi, Institut des Materiaux Jean Rouxel, France M.C. Fernandez, Institut des Materiaux Jean Rouxel, France C. Cardinaud, Institut des Materiaux Jean Rouxel, France |
| Correspondent: | Click to Email |
Quartz or pure fused silica is selected material for the fabrication of biochip devices and more specifically electrophoresis chips. Indeed, these materials benefit from transparency in the UV-visible range, and low dielectric breakdown. However material cost is higher in comparison to silica glass which offers similar properties with a low purity degree. Plasma deep etching techniques are well established for fused silica and quartz, but much more challenging for glass. In the present study, the etching simulator has been developed to study the etching of silica glass (Pyrex, D263, AF45, and Vycor) in SF6/Ar plasma. The etching model is based on the development of the plasma kinetic model coupled to 2D Monte Carlo surface model to predict the etched surface morphology of glasses as a function of the operating conditions.
The gas phase kinetic model is based on the mass balance equations of reactive species. The kinetic constants of electron impact reactions are established as a function of electron temperature assuming maxwellian distribution of electron energy. The additional equation of power balance in the ICP reactor allows to determine the electron temperature evolution with the plasma discharge parameters (Rf power, reactor pressure and SF6/Ar flow rates).
Langmuir probe is used to measure the electrical parameters of SF6/Ar plasma mixture such as, electron temperature and density as a function of the plasma discharge parameters. A good agreement between the simulations and the experiments have been observed
One of the advantages of our model is the coupling between the plasma chemistry model and the surface etching model. The later is based on the Monte-Carlo approach which allows to describe, in a probabilistic manner, the surface mechanisms for silica glass etching.
The direct fluxes of the reactive species such as fluorine and ions are determined from the gas phase kinetic model and introduced as the input parameters in the glass etching model.
On the other hand, surface analyses such as the etch rate, surface roughness (profilometry), and surface topography (AFM) of silica glass as a function of operating conditions have been carried out.
The preferential redeposition mechanism of the etched products on the metallic sites seems to play an important role on the propagation of the etched surface roughness. A satisfactory agreement between experimental results and the model concerning the etching rate and the etched surface morphology have been obtained for different glasses.