Numerical study of the plasma chemistry in inductively coupled SF₆ and SF₆/Ar plasmas used for deep silicon etching applications

A hybrid model, called the hybrid plasma equipment model, was used to study inductively coupled SF 6 plasmas used for Si etching applications. The plasma properties such as number densities of electrons, positive and negative ions, and neutrals are calculated under typical etching conditions. The electron kinetics is analysed by means of the electron energy probability function. The plasma chemistry taking place in pure SF 6 and in an Ar/SF 6 mixture is also discussed, and finally the effect of the argon fraction on the plasma properties is investigated.