Non‐basal plane SiC surfaces: Anisotropic structures and low‐dimensional electron systems

Abstract

AbstractThe polytype dependent stacking sequence in SiC is exposed on its non‐basal plane surfaces, and thus complex and anisotropic surface reconstructions can be expected. Detailed investigations of the atomic and electronic structure of a ‐plane (11$ \bar 2 $0) surfaces and diagonal cuts, namely (1$ \bar 1 $02) and ($ \bar 1 $10$ \bar 2 $) surfaces of 4H‐SiC are reviewed. After hydrogen etching the surfaces show large, flat terraces. Preparation in ultra‐high vacuum (UHV) leads to the development of well ordered surface phases. On 4H‐SiC(11$ \bar 2 $0) three unique and distinguishable (1 × 1) phases can be identified by monitoring the LEED spot intensities. On 4H‐SiC(1$ \bar 1 $02) surfaces three well ordered phases with different periodicity appear. The Si rich (2 × 1) phase is characterized by an ordered array of Si‐adatom chains which host an electronic surface state that is confined within the chains. A c(2 × 2) phase exists at a surface composition close to SiC bulk. At high temperatures a (1 × 1) phase develops which is carbon terminated with a graphite‐like bond configuration. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)