Physical sputtering of III-V-semiconductors with a focused Ga+-beam

InP. InAs. Gap. and GaAs were irradiated at room temperature and normal inc idence with the focused ion beam device IMSA 100 using ion energies ranging from 10 to 50 keV. Ion fluences up to 10(18) Ga-4 cm(-2) were applied in o rder to determine the physical sputter yield by means of atomic force micro scopy. A dynamic steady state of damage/implantation and materials removal was found to be reached for ail the materials within the range of the ion f luences applied. For comparison of the experimental data with theory in the frame of the binary collision model, the influence of modified materials p roperties and ion incorporation on the sputter yield was simulated using th e program codes TRIDYN as well as TRIM 87. The calculations indicate that i n addition to the profile of the incorporated ions a modification of the su rface binding forces has to be taken into account for the sputtering proces s. (C) 1999 Elsevier Science B.V. All rights reserved.