Eur. Phys. J. D 16, 271-274 (2001)
https://doi.org/10.1007/s100530170108

Electronic properties of assembled islands of hydrogen-saturated silicon clusters on Si(111)-(7×7) surfaces studied by scanning tunneling spectroscopy

¹ Joint Research Center for Atom Technology (JRCAT), Angstrom Technology Partnership, 1-1-1 Higashi, Tsukuba, Ibaraki 305-0046, Japan
² JRCAT, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan

Corresponding authors: ^a bolotov@jrcat.or.jp - ^b kanayama@jrcat.or.jp

Received: 30 November 2000
Published online: 15 September 2001

Abstract

We present results of scanning tunneling spectroscopy (STS) measurements of hydrogen-saturated silicon clusters islands formed on Si(111)-() surfaces. Nanometer-size islands of Si₆H₁₂ with a height of 0.2-4 nm were assembled with a scanning tunneling microscope (STM) using a tip-to-sample voltage larger than 3 V. STS spectra of Si₆H₁₂ cluster islands show characteristic peaks originating in resonance tunneling through discrete states of the clusters. The peak positions change little with island height, while the peak width shows a tendency of narrowing for the tall islands. The peak narrowing is interpreted as increase of lifetime of electron trapped at the cluster states. The lifetime was as short as 10^-13 s resulting from interaction with the dangling bonds of surface atoms, which prevents charge accumulation at the cluster islands.