The Effects of Strain on STM Lithography on HS-ssDNA/Au (111) Surface.

Scanning tunneling microscopy (STM) lithography was utilized to investigate a 12-mer HS-ssDNA self-assembled Au (111) surface. Under low sample bias and high tunneling current, the repeated scanning resulted in the growth of nanostripes. The stripe orientation, the stripe width, and the spacer width between adjacent nanostripes were found to be dependent on their relative locations from dislocation points where two adjacent gold terraces overlap. The stripe and the spacer width also vary with the distance from these points. The results indicate that such stripes may reflect the strain distributions and the release pathway along the Au surfaces. The results also suggest that the presence of HS-ssDNA molecules enhances the lithography processes on the gold surface by acting as force transmitters.