Orientation Modulated Epitaxy of Cu Nanorods on Si(1 0 0) Substrate

Epitaxial growth of Cu nanorod films on hydrogen-terminated Si(100) substrates by oblique angle deposition (OAD) was investigated. It is found out that the crystallographic orientation of Cu nanorod films exhibits a 45° in-plane rotation with respect to the substrate. When the incident angle of deposition was increased from normal to 80°, the distribution of Cu(111) poles is observed to spread out gradually, whereas the spread in poles is severe beyond 80°, indicating higher epitaxy quality for Cu deposited at lower incident angles. In addition, two sets of twin poles are induced at high-incident angles, while one set can be suppressed by altering flux direction 45° azimuthally about substrate normal. The mechanism of epitaxy development in the OAD grown Cu films is explained.