| AVS 58th Annual International Symposium and Exhibition | |
| Surface Science Division | Tuesday Sessions |
| Session SS-TuP |
| Session: | Surface Science Poster Session |
| Presenter: | Masamichi Yoshimura, Toyota Technolgocial Institute, Japan |
| Authors: | M. Yoshimura, Toyota Technolgocial Institute, Japan D. Matsuoka, Toyota Technolgocial Institute, Japan |
| Correspondent: | Click to Email |
With the miniaturization of semiconductor devices, low-dimensional structures such as quantum wires and quantum dots have recently attracted much attention. The “16 × 2” on a clean Si(110) surface has been noticed as an effective and unique substrate for the fabrication of low-dimensional nanostructures, because the one-dimensional undulated terrace structure of monatomic height and of about 2.5 nm width are formed. Because the hole mobility of Si(110) surface is about 1.5 times as large as that of Si(100) typically used as substrates of present semiconductor devices, higher speed operation is expected [1]. Thus, the interaction between Si(110) and metal is very important [2,3]. Aluminum is the typical metal forming Schottky barrier with silicon and the Al-adsorbed structures have been well examined on Si(111) or Si(001) plane [4,5]. In contrast, little is known about the structures of the Al/Si(110), particularly in real-space. In this study Al/Si(110) surfaces are investigated in real space using STM and first-principle calculation.
The experiments were carried out in an ultrahigh vacuum (base pressure: 2.0 × 10-8 Pa). First-principles calculation was performed using VASP program [6]. Aluminum was deposited on a clean Si(110)- “16 × 2” at 600 ℃ for 10 min to prepare a “4 × 6” reconstruction [7]. In the empty state, alternative arrangement of zigzag rows and straight rows is visible in empty states. In filled states, bright spots are prominent at the position of defects in the zigzag row. They are assumed to be silicon substitutional defects, as is the case for Al/Si(111) [8]. Thus we conclude Al and Si atoms formed zigzag and straight rows, respectively. In addition, the straight row of the silicon was composed of the silicon pentagon [9] as revealed by high-resolution STM. Based on the above observation, an atomic structural model is proposed and discussion will be made based on the theoretical calculation.
[1] T. Sato et al., Phys. Rev. B4 (1971) 1950. [2] Y. Ohira, Master Thesis, Toyota Tech. Inst. (2007). [3] Y. Ohira et al., Jpn. J. Appl. Phys, 47 (2008) 6138. [4] M. Yoshimura et al., Phys. Rev. B47 (1993) 13930. [5] H. Itoh et al., Phys. Rev. B48 (1993) 14663. [6] G. Kresse et al., Phys. Rev. B54 (1996) 11196. [7] A. V. Zotov et al., Surf. Sci. 277 L77 (1992). [8] R. J. Hamers, Phys. Rev. B40 (1989) 1657. [9] T. An et al., Phys. Rev. B61 (2000) 3006.