SURFACE SMOOTHING AND PATTERNING OF SIC BY FOCUSED ION-BEAMS

6H-SiC was irradiated at room temperature with focused Ga+ or Au+-beam s at different energies and ion fluences. The bombarded areas were inv estigated by means of atomic force microscopy. The measurements indica te a smoothing of the irradiated areas saturated at ion fluences of 7 x 10(16) Ga+ cm(-2). For higher ion fluences, sputtering dominates ove r a swelling, which is induced by irradiation damage and ion implantat ion. SIC can be removed in a well-defined three-dimensional geometry w ith a slope of the sidewalls up to 85 degrees, depending on the ratio of the beam diameter and the structure depth. The bottom of the sputte red structures is still very planar. The observed sputtering yields co uld be well fitted with TRIM 87 simulations using the surface binding energy as an input parameter. (C) 1998 Elsevier Science B.V. All right s reserved.