INTERACTION OF ETCH PLASMAS WITH SURFACES.

Recent results obtained about the mechanisms underlying anisotropic plasma etching as used for the transfer of patterns in very large scale integrated circuit technology are reviewed. Quantitative results on physical sputtering yields resulting from bombardment of elementary targets with inert atomic ions have been obtained down to the range of ion energies of interest in plasma etching, i. e. typically down to about 100 eV. It appears that the Sigmund model, originally expected to be valid only to about 1 keV, also quantitatively describes the results down to 100 eV.