The effects of the Fermi level on ion induced electron emission from chemically and sputter cleaned semiconductors

Plasma interactions with semiconductors comprise a variety of interesting phenomena in addition to etching and deposition. One such phenomenon is the process of low energy ion induced electron emission (IIEE). IIEE has historically been viewed as extremely surface sensitive; but recent measurements have suggested that the IIEE yield from semiconductors, unlike metals, may in fact depend on the sub-surface properties as well. We investigated the effects of the surface and sub-surface properties (doping type, Fermi level, cleanliness level) on the relative IIEE yields from Si and Ge. Our measurements found that the relative IIEE yields did not depend on the doping type to a significant degree independent of the level of cleanliness.