Effect of a magnetic field on the rate of etching of silicon dioxide in a CF4 + O2 plasma

A near-electrode nonuniform magnetic field crossed with an electric field is found to strongly affect the rate of etching of silicon dioxide on glass substrates in a CF4 + O-2 plasma when the Larmor frequency (a parts per thousand 10(9) s(-1)) is much higher than the frequency of collisions of an electron with surrounding plasma particles (a parts per thousand 10(6) s(-1)) and the frequency of the applied rf electric field (a parts per thousand 10(7) s(-1)). The confinement of electrons by the magnetic field in the immediate vicinity of the substrate surface to be treated increases the rate of generation of chemically active particles, which increases the etching rate of silicon dioxide.