Effect of a dielectric cavity on the ion etching of dielectrics by electron beam-produced plasma generated by a forevacuum plasma electron source

Abstract

We show that etching of a dielectric (quartz) target by ions from the beam-plasma formed using a forevacuum-pressure, plasma-cathode electron source is substantially greater when the beam-plasma and the target are located within a dielectric cavity. The effect of the cavity manifests itself in impeding the negative charge to escape from the dielectric surface of the target irradiated by the electron beam, thereby forming higher negative target potentials which accelerate the ions coming from the plasma and intensify the ion etching. The beam-plasma parameters (plasma density and electron temperature) are greater with the cavity than without the cavity due to additional energy input from secondary electrons emitted from the target and accelerated by a high target potential. Efficient ion etching of dielectrics can be performed in this way.