Observation of Crystalline Oxidized Silicon Phase

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Mikhail Kuzmin
  • Juha Pekka Lehtiö
  • Jaakko Mäkelä
  • Muhammad Yasir
  • Zahra Jahanshah Rad
  • Esa Vuorinen
  • Antti Lahti
  • Marko Punkkinen
  • Pekka Laukkanen
  • Kalevi Kokko
  • Hannu Pekka Hedman
  • Risto Punkkinen
  • Mika Lastusaari
  • Päivikki Repo

  • Associate professor Hele Savin

Research units

  • University of Turku

Abstract

Silica phases, SiOx forming at surfaces of various silicon crystals, e.g., Si wafers, nanowires, and nanoparticles via Si oxidation are key building blocks of diverse applications in the fields of electronics, medicine, and photonics for instance. The Si oxidation has been established to produce amorphous SiOx films, and the resulting oxide/silicon structures are prototypical junctions or contacts of amorphous and crystalline materials of which formation and properties have been extensively studied to understand and develop functionality of SiOx/Si in the applications. Here, observation of hitherto undiscovered phase of the SiOx/Si material, which is crystalline without traditional amorphous silica, is presented. The crystalline SiOx/Si structures are produced in vacuum environment via controlled oxidations of Si where O atoms are incorporated beneath the topmost Si layer. Concomitantly some Si atoms are detached from the crystal, and diffuse to the topmost surface, consistent with previous theoretical predictions, retaining still a pure Si-surface type reconstruction and leading to a crystalline stack of Si/SiOx/Si. In addition to providing a well-defined platform to studies of the SiOx/Si system, the found crystalline phase is also hypothesized to decrease amounts of disorder-induced defects in the applications. Presented electrical characterization via carrier-lifetime and capacitor measurements support the hypothesis.

Details

Original languageEnglish
Article number1802033
Number of pages9
JournalAdvanced Materials Interfaces
Volume6
Issue number6
Publication statusPublished - 22 Mar 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • atomic layer deposition, capacitors, defect levels, silica phases, silicon oxidations

ID: 32216664