High-speed etching of amorphous silicon using pin-to-plate dielectric barrier discharge

Atmospheric pressure plasma was generated using a modified dielectric barrier discharge (pin-to-plate DBD) with the power electrode consisting of multi-pins instead of a conventional blank planar plate. The discharge and amorphous silicon (a:Si) etching characteristics of the pin-to-plate DBD were compared with those of the conventional DBD at various N₂/NF₃ mixtures. The pin-to-plate DBD showed higher power consumption and higher discharge current than the conventional DBD-type at a given voltage. Therefore, the pin-to-plate DBD appeared to be more efficient than the conventional DBD. In addition, the pin-to-plate DBD showed higher a:Si etch rates than the conventional DBD at various N₂/NF₃ mixtures. With the pin-to-plate DBD, a maximum etch rate of a:Si of 72 nm/s were obtained with an electrode size of 170 mm × 100 mm, a gas mixture of 0.75% NF₃ in N2 and an AC voltage of 18 kV when the sample was stationary.