d$)$ Write down a set of important chemical reactions in the plasma due to collisions between $CC{l}_4$ and electrons.

Chemical species formed in the reactions between $CC{l}_4$ and electrons will then bombard the silicon wafer. Describe the reactions at the surface that lead to:

i$)$ isotropic etching of the silicon wafer?

ii$)$ an$-$isotropic etching of the wafer?

e$)$ In such a plasma there are no negative ions and the electron density is $5x{10}^{16}{m}^{-3}.$ If $CC{l}_3^{+}$ions have a mass of $1\mathrm{.}98{10}^{-25}kg$ and are the dominant ionic species:

i$)$ Calculate both the electron and $CC{l}_3^{+}$ion plasma frequencies, ${}_{pe}$ and ${}_{}.$

ii$)$ Do $CC{l}_3^{+}$ions respond to the changing RF potentials in the plasma?