Characterization of low pressure plasma-dc glow discharges (Ar, SF6 and SF6/He) for Si etching

Low-pressure plasma reactor which is generated for SF6, SF6/He and Ar gases discharges between two metal electrodes (planer -parallel) using dc-high voltage power supply of 2 kV has been proposed. Paschen's curves show the breakdown voltage of gases as a function of the parameter p*d which is the product of the pressure in the chamber (P=6.5x10(-2)-1.5x10(-1) mbar) and the distance between the two electrodes (d=4.6 cm). The minimum breakdown voltages were found 450 V at pressure of 1.35x10(-1)mbar and 276 V at pressure of 4.3x10(-1) mbar for SF6 and Ar, respectively. Current-voltage characteristics have been studied at different values of pressure (6.5x10(-2)-1.5x10(-1) mbar) and inter-electrodes spacing (3.4, 4.2, 4.6, 5 cm). The SF6, SF6/He and Ar gases discharges plasmas in Si etching have been discussed.