Deep level defects in Ga- and N-polarity GaN grown by molecular beam epitaxy on si(111)

Koteswara Rao Peta, Sang Tae Lee, Moon Deock Kim, Jae Eung Oh, Song Gang Kim, Tae Geun Kim

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Deep level transient spectroscopy has been used to characterize the deep level traps in Ga- and N-polarity GaN films grown by plasma assisted molecular beam epitaxy on Si(111) substrate. The two deep level traps at E c-Et∼0.21 eV (E1) and Ec-E t∼0.48 eV (E2) have been detected in Ga-polarity GaN. The E1 level commonly observed deep trap related to the nitrogen vacancy in GaN. It is found that, the E2 level exhibits logarithmic capture kinetic behavior and substantially increases its capture cross section from 10 -15 to 10-12 cm2 by employing different pulse width ranging from 5 ms to 35 ms. Such behavior of E2 trap with filling pulse length attributes that, the trap is originated from threading dislocations. In case of N-polarity GaN, we observed two deep level traps with activation energies of Ec-Et∼0.53eV (E3) and E c-Et∼0.89eV (E4). The estimated capture cross-sections (σs) for these defects were found to be ∼2.51×10-15cm2 and ∼5.21×10 -16cm2 respectively. The E3 and E4 are nitrogen antisite point defect and extended defect related to dislocation deep levels, results from growth on N-polarity crystal structure. Crown

Original languageEnglish
Pages (from-to)299-302
Number of pages4
JournalJournal of Crystal Growth
Volume378
DOIs
Publication statusPublished - 2013

Keywords

  • Defects
  • Molecular beam epitaxy
  • Nitrides
  • Semiconducting III-V materials

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

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