2006 Fiscal Year Final Research Report Summary
High precision surface potential imaging using scanning probe microscopy
| Project/Area Number |
17360018
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Thin film/Surface and interfacial physical properties
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
HASEGAWA Yukio The University of Tokyo, The Institute for Solid State Physics, Associate Professor (80252493)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HAMADA Masayuki The University of Tokyo, The Institute for Solid State Physics, Technical staff (00396920)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Keywords | scanning probe microscopy / electrostatic potential / screening effect / Friedel oscillation / quartz resonator |
|---|
| Research Abstract |
In this project, we developed surface potential measurement and imaging methods using scanning tunneling microscopy (STM) and atomic force microscopy (AFM) with a potential resolution less than 10 mV and a nano-scale spatial resolution. To our STM setup we installed two-dimensional tunneling spectroscopy, which takes a tunneling spectrum at every site during the STM imaging. The precise potential imaging was achieved through the measurements of an energy level variation of surface states using the two-dimensional tunneling spectroscopy. With the STM potential measurement method, we successfully imaged potential screened by two-dimensional electron system originating from surface electronic states and subsequent Friedel oscillation, and confirmed that the potential distribution is well explained with theoretical results based on the dielectric function of the 2D electron system. As for AFM, we set up Kelvin-probe force microscopy for the potential measurement, and successfully detected the potential difference due to charge transfer among atoms on semiconductor surfaces.
We also worked on a development of liquid He cooked low temperature AFM aiming for improved performance of the potential measurement. We tested a performance of length-extension type quartz resonator, which is used as a force sensor in the low temperature system, and found it works well. A new tip-sharpening method, necessary for the operation of the quartz resonator, using a micromanipulator and focused ion beam was developed.
|
