High-speed etching of SiO2 using a remote-type pin-to-plate dielectric barrier discharge at atmospheric pressure

Abstract

High speed etching of SiO2 has been investigated using a remote-type dielectric barrier discharge (DBD) in-line system with a multi-pin-to-plate power electrode configuration as functions of N2/NF3 gas combination, added gases and operating frequency of a pulse power supply. The SiO2 etch rate increased with an increase in NF3 flow rate (0.2–1.0 slm) in N2 (60 slm)/NF3 but showed a maximum with an increase in N2 (30–80 slm) at 60 slm in the N2/NF3 (1 slm) gas mixture. The SiO2 etch rate was also increased with the addition of up to 0.6 slm of He or Ar gas and it was also related to the increase in fluorine atomic density in the plasma. The addition of He or Ar to the N2 (60 slm)/NF3 (1 slm) and the increase in the frequency of the pulse power increased the fluorine atomic density through the increased Penning ionization/dissociation and the increased ionization by the increased pulse-on time, respectively.