SCANNING TUNNELING MICROSCOPE-PROMOTED GROWTH OF NANOMETER-SCALE, UNIFORM GOLD STRIPES ON RECONSTRUCTED AU(111) SURFACES

Scanning the scanning tunneling microscopy (STM) tip on a Au(111) (22 +/- 1) x square-root 3 reconstructed surface causes monatomic stripes to grow preferentially on the fcc portions of the surface. Stripes several 100 nm's in length, approximately 4 nm wide, and separated by spaces ranging from 2 to approximately 4 nm (the hcp regions of the reconstructed surface) can be grown. Stripe formation only takes place when the scan direction corresponds, more or less, with the [1,1,-2] primary direction of the reconstruction. Growth occurs much more rapidly than can be accounted for by diffusion alone, leading to the conclusion that the STM tip transports gold, previously picked up from other portions of the surface, to the growing ends of the stripes. Stripes grown in this way may serve as convenient templates for subsequent growth of quantum wire structures by molecular beam epitaxy.