AVS 53rd International Symposium
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS2-TuM

Invited Paper NS2-TuM5
Site-Specific Force spectroscopy and Following Artificial Nanostructuring

Tuesday, November 14, 2006, 9:20 am, Room 2020

Session: Nanoscale Manipulation and Assembly
Presenter: S. Morita, Osaka University, Japan
Authors: S. Morita, Osaka University, Japan
Y. Sugimoto, Osaka University, Japan
O. Custance, Osaka University, Japan
M. Abe, Osaka University, Japan
Correspondent: Click to Email
We are developing a novel versatile "Bottom Up Nanotechnology", which can construct artificial nanostructures consisted of many kinds of elements by using a high-resolution and high-performance AFM that can identify chemical species of individual atoms and can manipulate individual atoms even at room temperature (RT). Noncontact AFM image can give different contrast between intermixed two chemical species. However, we cannot identify chemical species of intermixed atoms from atom selective imaging on only one sample without changing relative ratio of intermixed atom species. To achieve more straightforward chemical identification than atom selective imaging at RT, we developed precise atomic force measurement method of individual atoms as a function of tip-sample distance at RT by compensating thermal drift using an atom tracking method and then by averaging reproducibly obtained many site-specific frequency shift curves. Next we converted site-specific frequency shift curve to site-specific force curve. Then, by subtracting long-range force due to Van der Waals force, we obtained short-range atomic force curve of selected individual atoms at RT. Thus we achieved precise force spectroscopy of selected individual atoms at RT. In addition, AFMs under non- and near-contact modes operated at low-temperature (LT) and at room-temperature (RT) were used for investigations of vertical and also lateral atom manipulations of selected single atoms on semiconductor surfaces. Recently, using nearcontact AFM, we found a lateral atom-interchange phenomenon at RT and constructed "Atom Inlay", that is, atom letters "Sn" consisted of 19 Sn atoms embedded in Ge(111)-c(2x8) substrate. Furthermore, we observed atom interchange manipulation phenomena even in Sn/Si(111)-(@sr@3x@sr@3), In/Si(111)-(@sr@3x@sr@3) and Sb/Si(111)-(7x7) intermixed systems with not only Si but also In (acceptor element in crystal Si) or Sb (donor element in crystal Si) atoms.