Nanowire Reconstruction on the 4H-SiC(1-102) Surface

• Ordered reconstruction phases on the 4H-SiC(1102) surface have been investigated usinglow-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and scanning tunnelingmicroscopy (STM). After initial hydrogen etching, the samples were prepared by Si deposition andannealing in ultra-high vacuum (UHV). Two distinct reconstruction phases develop upon annealing,first with a (2×1), and at higher temperatures with a c(2×2) LEED pattern. After further annealingthe fractional order LEED spots vanish and a (1x1) pattern develops. For the (2×1) phase, STMmicrographs show that adatom chains develop on large flat terraces, which in view of AES consistof additional Si. These highly linear and equidistant chains represent a self-assembled well-orderedpattern of nanowires developing due to the intrinsic structure of the 4H-SiC(1102) surface. For thec(2×2) phase AES indicates a surface composition close to the bulk stoichiometry. For the (1×1)phase a further Si depletion is observed.

Keyword

Surface structure

Reconstruction

Nanowire

4H-SiC

SiC(1102)

Low-Energy Electron Diffraction

Scanning Tunneling Microscopy

Auger Electron Spectroscopy

LEED

AES

STM

One-dimensional electronic state.

Publication and Content Type

ref (subject category)

kon (subject category)