Over the last few years there has been increasing need for systematic
and straregically designed experiments of surface morphology evolution
resulting form ion bombardment induced sputtering. Although there is an
impressive number of investi- gations {1} concerned with semiconductor
materials as a result of immediate applications, the most systematic
investigations have been conducted with fcc metals with particular
interest on single crystal Cu {2,3}. Evidence now exists that within
certain para- meters (i. e ion species (Ar+), ion energy (20-44 KeV),
substrate 2 temperature (80-550° K), dose rate (100-500 gA cm- ),
residual x 5 9 pressure (5 10- to 5x10- mm Hg) and polar and azimuthal
angle of ion incidence {4} reproducible surface morphology (etch pits
and pyramids) is achieved on the (11 3 1) specific crystallographic
orientation. The temporal development of individual surface features was
alsoobserved in this laterstudy {4}, by employing an in situ ion source
in the scanning electron microscope at Salford, a technique also
empolyed in studies of the influence of polar angle of ion incidence {5}
and surface contaminants {6} on the topographyof Ar+ bombarded Si.
Studies have also been made on the variation of incident ion species
with the (11 3 1) Cu surface and it was fully recognized {7} that
residual surface contaminants when present could playa major role in
dictating the morhological evolution.