title: Transport spectroscopy of coupled donors in silicon nano-transistors.
abstract: The impact of dopant atoms in transistor functionality has significantly changed over the past few decades. In downscaled transistors, discrete dopants with uncontrolled positions and number induce fluctuations in device operation. On the other hand, by gaining access to tunneling through individual dopants, a new type of devices is developed: dopant-atom-based transistors. So far, most studies report transport through dopants randomly located in the channel. However, for practical applications, it is critical to control the location of the donors with simple techniques. Here, we fabricate silicon transistors with selectively nanoscale-doped channels using nano-lithography and thermal-diffusion doping processes. Coupled phosphorus donors form a quantum dot with the ground state split into a number of levels practically equal to the number of coupled donors, when the number of donors is small. Tunneling-transport spectroscopy reveals fine features which can be correlated with the different numbers of donors inside the quantum dot, as also suggested by first-principles simulation results.
authors.affiliation: Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moraru
authors.affiliation: Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan.
authors.forename: Arup
authors.initials: A
authors.lastname: Samanta
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi 923-1292, Japan.
authors.forename: Le The
authors.initials: le T
authors.lastname: Anh
authors.affiliation: Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mizuno
authors.affiliation: 1] School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi 923-1292, Japan [2] Nano Research Group, ECS, Faculty of Physical Sciences and Engineening, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuta
authors.affiliation: Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan.
authors.forename: Michiharu
authors.initials: M
authors.lastname: Tabe