Optical diagnostics have been previously employed in
real-process-simulating plasmas and have been proven very useful to better understand the processes involved and to elucidate the role of the various plasma species. In the proposed project, emission spectroscopy and mass spectmetry will be employed in a production-type environment, devoted to the production of Si-based nanostructures.
Recently, the host institution has developed a promising method for Si etching in a radio-frequency reactor, using CHF3/SF6 mixtures to provide a highly anisotropic, selective and environmentally friendly chemistry. The proposed plasma diagnostics, in conjuction with surface characterization, will further contribute to the understanding of the mechanism in the aforementioned chemistry, to the optimization of the discharge operating conditions, and to the formulation of new environmentally friendly etching recipes. Ultimately, defined optimum processes will be extended to the etching of other technologically interesting materials (poly-Si, SiGe) and to high density plasma reactors.