SIMS depth resolution studies in AlxGa1−xAs using specially grown MBE samples

A quantitative analysis of the effect that the surface roughening due to oxygen ion bombardment has on the depth resolution of SIMS profiles has been carried out for the semiconductor alloys AlxGa1−xAs (x = 0, 0.175, 0.384 and 0.69) for a range of bombardment energies from 2 keV to 10.5 keV in two Cameca IMS 3F instruments. The loss of depth resolution is greater (and occurs at greater depths) with higher impact energies but occurs more rapidly with increasing x values. Good correlation is observed with the secondary ion signal intensity changes caused by surface roughening. No change of sample erosion rate is observed. No similar effect could be found with Cs, Ar, Xe, N or N2 bombardment.