Atomic probe imaging of β-SiC thin films grown on (100) Si

Atomic-scale imaging has been achieved on β-SiC surfaces using scanning tunneling microscopy in air. SiC films were grown on Si (100) substrates by chemical vapor deposition using the carbonization reaction of the surface with C3H8, followed (for films thicker than 100 nm) by the reaction of C3H8 and SiH4. For a relatively thick SiC (∼6 μm) film, the average nearest-neighbor surface atomic spacing measured was 3.09 Å, which is very close to the nominal value of 3.08 Å. Several of the thinner (<100 nm) SiC films exhibited significantly larger atomic spacings, indicating the strong effect of the larger atomic spacing (nominally 3.84 Å) of the Si substrate.