Si Dimer Chain on Si(100)-2×1:H Surface Fabricated by Scanning Tunneling Microscope

Abstract

In order to fabricate an atomic chain with metal, semiconductor and insulator phases on an atomically flat insulating surface by manipulating single atoms one by one with an ultrahigh-vacuum scanning tunneling microscope (UHV STM), we investigated the Si(100)-2×1 surface and its hydrogen termination. The obtained STM images show that the Si(100)-2×1 surface will have fewer defects when appropriate preparation is employed. We successfully prepared the monohydride Si(100)-2×1:H surface using the dry etching process. Hydrogen atoms on the Si(100)-2×1:H surface can be extracted by applying both positive and negative voltage pulses between the STM tip and the sample surface with a certain tunneling current. This implies that the mechanism for extracting hydrogen atoms on the monohydride surface is due to not only electron excitation but also field evaporation. There is a pairing effect to force extracted hydrogen atoms in pairs from dimers. Using this technique, we fabricated a Si dimer chain on the Si(100)-2×1:H surface by removing pairs of hydrogen atoms.