Sputtering yields of Si, SiC, and B4C under nanodroplet bombardment at normal incidence

Abstract

Single-crystal silicon and polycrystalline silicon carbide and boron carbide were bombarded with a beam of electrosprayed nanodroplets at normal incidence. The acceleration voltage of the beam ranged between 9.13 and 20.13 kV. The kinetic energy of the nanodroplet molecules varied between 24.1 and 91.2 eV. The volume of sputtered material was measured with a profilometer, and the molecular flux of the beamlet with a time of flight spectrometer. Sputtering yields as high as 2.32, 1.48, and 2.29 atoms per molecule were obtained for Si, SiC, and B4C. The maximum receding rates of the substrates’ surfaces were 448, 172, and 170 nm/min respectively. The significant increase with respect to the sputtering rates of broad-beam atomic ion sources is due to the large molecular flux of electrosprays.