Radio-frequency sputtering cannot be used for absolute measurements of sputtering yields because of the spread in energies of the bombarding ions. This paper describes how these yields can be studied by simultaneously sputtering with the insulators other materials with known dc sputtering yields. Silicon and germanium were selected as reference materials. The dielectric materials studied were fused quartz, Pyrex 7740 glass, Pyrex 7059 glass, soda lime glass, and aluminum oxide (Lucalox). The experiments were performed in an Argon atmosphere at 3 × 10−3 Torr and at rf electrode potentials between 1.3 and 3.9 kV peak-to-peak. The frequency in all experiments was 13.56 MHz. Sputtering yields were found to be highest for fused quartz (0.16 to 0.5 molecules/ion) and lowest for aluminum oxide (0.04 to 0.17 molecules/ion). The data for fused quartz were found to fall between published low-energy yields determined by Langmuir probe and very high-energy yields determined by ion beams.

Davidse, P. D., & Maissel, L. I. (1967). Equivalent dc Sputtering Yields of Insulators. Journal of Vacuum Science and Technology, 4(1), 33–36.