Universal energy dependence of physical and ion-enhanced chemical etch yields at low ion energy

Abstract

Physical and ion-enhanced chemical etch yields are shown to be a linear function of the square root of the ion energy down to the etching threshold for self-sputtering of metals, sputtering of metals by noble gas ions, sputtering of Si and SiO2 by noble gas and reactive ions, and ion beam enhanced chemical etching of Si. The threshold energy must be taken into account for a quantitative description of etch yields even at intermediate ion energies. The relationship between the dependence of etch yields on ion energy and incident angle is also discussed.