 |
Education |
|
Ph. D. in Engineering (Osaka University, 2000) |
|
"Observations of Si surfaces after industrial processes by scanning
tunneling microscopy and spectroscopy" |
|
|
|
Professional Experience |
|
 |
Junior Research Associate (The Institute of Physical and Chemical Research
(RIKEN)) (1997-2000) |
|
|
Visiting Scholar (Lawrence Berkeley National Laboratory) (2007-2008) |
|
|
Assistant Professor (Osaka University) (2000-2009) |
|
|
Associate Professor (Osaka University) (2009-) |
|
|
|
|
Publications |
|
|
Listed on a separate sheet  . |
|
|
|
|
Research Grantee |
|
|
The Murata Science Foundation (2002). |
|
|
Shimadzu Science Foundation (2004). |
|
|
Osaka University supporters association (2004). |
|
|
Nissan Science Foundation (2005). |
|
|
Kansai Research Foundation for technology promotion (2006). |
|
|
Yazaki Memorial Foundation for Science and Technology (2006). |
|
|
The Mazda Foundation (2006). |
|
|
Foundation of Promotion of Material Science and Technology of Japan (2007). |
|
|
Inamori Foundation (2007). |
|
|
Tokuyama Science Foundation (2007). |
|
|
The Japan Securities Scholarship Foundation (2007). |
|
|
Yamada Science Foundation (Support for Long Term Visit) (2007-2008). |
|
|
Izumi Science and Technology Foundation (2009). |
|
|
Ministry of Education, Culture, Sports, Science and Technology. |
|
|
[Grant-in-Aid for the Encouragement of Young Scientists (2001-2002, 2003-2004,
2005-2006)] |
|
|
[Grant-in-Aid for Scientific Research on Priority Areas (2007)] |
|
|
|
|
Current Memberships |
|
|
Materials Research Society |
|
|
The Japan Society of Applied Physics |
|
|
The Surface Science Society of Japan |
|
|
The Japan Society for Precision Engineering (*) |
|
|
|
(*) Session Organizer since 2002 |
|
|
|
Professional Qualification |
|
|
Hazardous materials officers license [Class B, Group 4] (Japan Fire Engineering
Qualification Center) |
|
|
|
|
Research Interests |
|
I am interested in nanometer-scale measurements and evaluations of semiconductor
surfaces after various industrial processes such as wet cleaning, global
planarization processes, thin film growth and oxidation. I have been applying
various surface analyses in order to fulfill the requirement from device
fabrications and wafer manufacturing. I am familiar with scanning tunneling
microscopy/spectroscopy(STM/STS), Fourier transform infrared spectrometry
with attenuated total reflection arrangements(FTIR-ATR), low energy electron
diffraction(LEED), thermal desorption spectroscopy(TDS) and inductively
coupled plasma mass spectroscopy (ICP-MS). |
|
|
|
 |
Research Topics related to scanning tunneling microscopy |
|
|
Atomic-scale analysis of Si surfaces after wet cleaning |
|
|
For the fabrication of ultralarge scale integration devices in the next
generation, it is absolutely necessary to understand the structure of Si
surfaces on an atomic scale after wet cleaning. Especially, clarification
of the atomic structure of the hydrogen-terminated Si(001) surface after
diluted HF cleaning and subsequent rinsing with water is important. |
|
|
We have succeeded in obtaining clear atomic images exhibiting ideal 1x1
dihydride patterns after dilute HF cleaning by scanning tunneling microscopy.
In addition, we have revealed that the 1x1 dihydride structure disappears
when the surface is subsequently rinsed with water, because every other
dihydride row of the ideal 1x structure is preferentially etched in water. |
|
|
|
|
|
 |
|
 |
A magnified STM image (3.5x3.5 nm2) after HF cleaning. An ideal 1x1 structure is clearly resolved. |
 |
A magnified STM image (3.5x3.5 nm2) after subsequent rinsing with water for 10 min. Every other dihydride
row is missing. See J. Appl. Phys. vol. 91, pp. 4065 (2002). |
| STM image after HF cleaning (20x20 nm2). See Appl. Phys. Lett. vol. 76, pp. 463 (2000). |
|
|
|
|
|
|
|
Recently, Si(110) attracts attentions as a substrate for CMOS circuits
because it has been reported that the hole mobility of Si(110) is now higher
than that of Si(001). It is well known that the interface roughness determines
the carrier mobility of MOS transistors. In order to realize the higher
performance of CMOS circuits on Si(110) wafers than that today, the influence
of wet cleaning processes on microroughness of Si(110) surfaces must be
clarified. Atomically resolved STM observations are performed after HF-containing
solution, and subsequent rinsing with water. The atomic arrangements change
drastically by moderate rinsing with water. |
|
|
.jpg) |
.jpg) |
|
|
STM image of hydrogen-terminated Si(110) after dipping into dilute HF-containing
solution (34x34 nm2). |
|
STM image of Si(110) surface after subsequent rinsing 7x7 nm2. Characteristic features such as zigzag chains inside a terrace, a single
row at step edges and an isolated zigzag row on a terrace are observed.
See Appl. Phys. Lett. vol. 85, pp. 6254 (2004). |
|
|
|
|
|
Visible light irradiation effects on STM/STS observations of intrinsic
hydrogenated amorphous silicon surfaces |
|
|
Intrinsic hydrogenated amorphous Si (a-Si:H) is widely used in the active
layer for solar cells. It has been predicted that surface topographies
reflect growth processes. Hence the surface structure of a-Si:H must be
investigated on the nanometer scale. External light during STM observations
enables us to obtain highly resolved images because of photoexcited minority
carriers leading to the appearance of a higher voltage across the vacuum
than that in the dark. We have found that the increment of the tunneling
current is different at each surface site. This indicates that visible
light irradiation onto intrinsic a-Si:H surfaces during STM/STS measurements
can be helpful to extract either the local electronic or structural information
of a-Si:H. |
