AVS 51st International Symposium
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS-TuP

Paper NS-TuP25
Fabrication of SiGe Nanodot Array by Anodic Aluminum Oxide Templation

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: W.J. Huang, National Nano Devices Laboratories, Taiwan
Authors: W.J. Huang, National Nano Devices Laboratories, Taiwan
F.M. Pan, National Chiao Tung University, Taiwan
D.M. Chen, National Chiao Tung University, Taiwan
Correspondent: Click to Email
Anodic aluminum oxide (AAO) has a highly ordered hexagonal pore array structure, and has been widely used as a template for nanostructured materials fabrication, such as carbon nanotubes and TiO@sub 2@ nanodots. Silicon germanium (SiGe) is an interesting semiconductor, which has a higher carrier mobility as compared with silicon, and has tunable bandgaps depending on the atomic composition of Ge. Moreover, SiGe is process-compatible with existing Si IC technologies. In conjunction with the AAO templation method and simple dry etching, we have prepared SiGe nanodot array with a dot size smaller than 50 nm. Si@sub 0.85@Ge@sub 0.15@ 50 nm in thickness was deposited on the Si wafer by ultrahigh vacuum chemical vapor deposition (UHV-CVD), followed by the sputter-deposition of TiN (20 nm). An Al film 4 µm in thickness was thermally evaporated on the TiN surface for the AAO preparation. The Al film was anodically oxidized in an oxalic acid electrolyte at room temperature, and the finished AAO pore array has a pore diameter about 60 nm. As the Al layer was completely oxidized, the underlying TiN layer was partially oxidized as well resulting in the formation of the TiO@sub 2@ nanostructure array with a pattern in compliance with the AAO pattern. The TiO@sub 2@ array was then used as the hardmask for dry-etching the remaining TiN and the SiGe bottom layer, and the SiGe nanodot array was thereby produced. Various analytical techniques, such as TEM, AFM and AES, have been employed to characterize the process steps of the SiGe nanodot array.