SCANNING TUNNELING MICROSCOPY SPECTROSCOPY OF DANGLING-BOND WIRES FABRICATED ON THE SI(100)-2X1-H SURFACE/

We present a scanning tunneling microscopy/spectroscopy (STM/STS) stud y of atomic-scale dangling-bond (DB) wires on a hydrogen-terminated Si (100)-2 x 1-H surface. In the case of DB wires made of paired DBs, the STS shows semiconductive electronic states with a band gap of approxi mately 0.5 eV. The DB wires made of both single and paired DBs show a finite density of states at Fermi energy and do not show semiconductiv e band gaps. We have succeeded in making an atomic-scale wire that has a finite density of states at Fermi energy on a semiconductive surfac e. The results are in good agreement with a recent first-principles th eoretical calculations. (C) 1998 Elsevier Science B.V. All rights rese rved.