Hokkaido University Global Center of Excellence (COE) Program, Hokkaido University Graduate School of Information Science and Technology

Outline:
Utilizing the high density quantum nanostructure of compound semiconductors formed via an unique selective organometallic vapor phase growth method, I am working on high density integration of monoelectron devices and research into semiconductor nanowire that contains new features. A unique point of this research is the use of an ingenious method to achieve high density semiconductor quantum nanostructure/nanodevices smaller in size than the previous limits of nanofabrication technology allowed.

Research Results:
I initiated first of its kind research into the structure of quantum wire and quantum dots as a foundation for research on quantum/nano devices, and this research has so far produced a number of pioneering results. The first attempt at the formation of solid quantum structures successfully utilizing the attributes of crystal formation resulted in the formation of high density quantum wire (lateral superlattice) on a minutely inclined compound semiconductor substrate thanks to our metalorganic vapor phase epitaxy method. Subsequently, the published report of this experiment (APL 1987, JVST 1988) has been cited in the extracts of over 100 theses since. Furthermore, concerning the manufacture of solid quantum structures through selective growth, I have published a large number of research papers, including one related to successful fabrication of the world's first GaAs quantum dot (APL 1991; cited 159 times). This research has not only opened the door to new fields of research such as quantum wire and quantum dots, but has also contributed to crystal growth mechanism elucidation at the atomic level.

On the basis of these results, I accomplished the following between 1997 and 2000 while working on a specially-promoted research project entitled "Research and Assessment of the Formation and Structure of High Density Semiconductor Quantum Dots":
1) Proposal of a coupled dot array with quantum wires and quantum dots forming a networked state along with the actualization of such a structure through MOVPE selective growth.
2) Fabrication of wire-dot-wire structures through MOVPE selective growth and and the successful manufacture of a monoelectron transistor that couples quantum dots and wires through tunnel barriers via gate voltage application.

Between the 2001 and 2005 academic years, I developed founding scientific research entitled, "Monoelectron Integrated Electronics via Metalorganic Chemical Vapor Deposition High Density Quantum Nanostructure", and based on an already new architecture (BDD: Binary Decision Logic Graph), I succeeded in the development of a monoelectron logic circuit. Moreover, I am succeeding in the fabrication of high density, highly uniform GaAs photonic crystals with atomic level flatness - a contingent challenge of and directly related to this research.

Beginning in the 2006 academic year and based on the results of my previous research, I started specially promoted research on "Creation of Semiconductor Nanowire Electronics via Metalorganic Vapor Phase Selective Growth Methods." From this, I am currently conducting research on the search for new physical properties of one-dimensional structures and applications of nanowire devices.

Research Evaluations:
Regarding my 1997-2000 specially promoted research and 2001-2006 founding scientific research, an evaluation carried out by the Science Council's Scientific Research Expense Grant Auditing Section later made public on the council's website rewarded both projects a grade of "A: Progressed in line with expectations", and both continue to received high appraisal (http://www.jsps.go.jp/j-grantsinaid/index.html, 2006/12/12).

●Apr. 1975 Researcher, Musashino Electrical Communication Laboratory, Nippon Telegraph and Telephone Public Corporation Research on GaAs and related semiconductor superlattices and quantum structures grown by MOCVD
●Feb. 1990 Group leader, Basic Research Laboratories, Nippon Telegraph and Telephone Corporation
Researches on MOCVD-based semiconductor quantum wires and nanostructures including quantum dots
●Oct. 1991 Professor, Research Center for Interface Quantum Electronics, Hokkaido University
Fabrication and characterization of semiconductor quantum wires and quantum dots and the application of a single-electron device
●Apr. 2001 Professor, Research Center for Integrated Quantum Electronics, Hokkaido University
●Apr. 2004 Professor, Graduate School of Information Science and Technology, Hokkaido University
●Apr. 2005 Director, Research Center for Integrated Quantum Electronics, Hokkaido University