Formation of anomalous defect structure on GaSb surface by low temperature Sn ion-implantation

Noriko Nitta, Masafumi Taniwaki, Tomoo Suzuki, Yoshihiko Hayashi, Yuhki Satoh, Toshimasa Yoshiie

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

Defect formation in (100) GaSb by 60 keV Sn+ ion-implantation at 150-153 K is investigated using cross-sectional TEM, SEM and EDX. An anomalous structure consisting of many cells, which looks like a honey comb, was formed on the surface implanted with 8.9×1018 ions/m2. The diameter and the depth of a cell were about 50 nm and 220-250 nm respectively. The thickness of the walls partitioning the cells was about 10 nm. The upper part of the partitioning wall is amorphous and rich in Ga, while the lower part shows crystalline structure. A heavily strained region of 50 nm thickness, corresponding to the maximum depth of the projected Sn ions, was observed under the cells. This defect structure is compared with similar defects which have been observed in ion-implanted GaSb. The defect formation mechanism is discussed, and an explanation based on movement of the implantation induced point defects is proposed. It is assumed that hills and hollows are formed in the early stage of implantation. The point defects created on the hills do not contribute to the development of the defect structure, because they annihilate almost completely by the recombination of vacancy and interstitial and by the movement to the near surface sink. However, under the hollows, vacancies which escaped recombination remain, and the interstitial atoms, which are highly mobile at low temperatures, migrate far from there to aggregate under the hills. The hollows become deeper by the movement of the remaining vacancies to the surface, and the hills develop into the walls by the migration of the interstitial atoms from the surrounding hollows.

Original languageEnglish
Pages (from-to)674-680
Number of pages7
JournalMaterials Transactions
Volume43
Issue number4
DOIs
Publication statusPublished - 2002 Apr

Keywords

  • Amorphous
  • Anomalous behavior
  • Cavity
  • Cross-sectional transmission electron microscopy
  • Defect formation mechanism
  • Defect structure
  • Elevation
  • Energy dispersive X-ray spectroscopy
  • Fourier transformation
  • Gallium antimonide
  • High resolution transmission electron microscopy
  • Honey-comb
  • III-V compound semiconductor
  • Interstitial
  • Local composition
  • Low temperature implantation
  • Microtwin
  • Point defects
  • Scanning electron microscopy
  • Strain
  • Surface defect
  • Swelling
  • Tin ion-implantation
  • Vacancy
  • Void

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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