FORMATION OF NITRIDE LAYERS ON 6H-SIC SURFACES

The interaction of nitrogen with differently reconstructed 6H-SiC surf aces and thin Si adlayers on Si-terminated SiC surfaces was investigat ed. Clean (0001) and (<000(1)over bar>) surfaces were obtained in ultr ahigh vacuum by heating them either in the presence of a Si flux at di fferent temperatures or by annealing. For nitridation, a RF plasma sou rce was used. X-ray photoelectron spectroscopy results reveal the form ation of a 9 Angstrom thick silicon nitride surface layer via an anion exchange on bulk-truncated 6H-SiC surfaces at room temperature. The f ilm thickness initially rises with increasing sample temperature durin g nitrogen exposure up to about 14 Angstrom but decreases for temperat ures above 1150 K. In order to obtain thicker nitride layers, we depos ited thin Si layers on Si-terminated SiC surfaces. (C) 1998 Elsevier S cience B.V. All rights reserved.