Experimental determination of the rates of decomposition and cation desorption from AlN surfaces

Z. Y. Fan, Nathan Newman

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The decomposition rate of AlN thin films in vacuum, nitrogen gas and plasma is reported. The AlN thermal decomposition rate in vacuum is found to have an activation energy of 5.4 eV. The evaporation coefficient is inferred to be less than 0.001, indicating that this process is kinetically limited. Large kinetic energy ion bombardment ( ∼ 70 eV), which occurs in the plasma at low nitrogen pressures (0.02 mT), is found to enhance the decomposition rate by a factor of ∼ 2. In contrast, exposure to 0.3 mT nitrogen pressure or low kinetic energy plasmas ( ∼ 25 eV) at similar pressures diminishes the AlN evaporation rate by a factor of ∼ 3. This result can be attributed to the chemical reactivity of the desorption site, presumably at a kink or step edge. Plasmas containing predominantly excited atomic species do not significantly change the decomposition rate. Temperature-dependent measurements of the aluminum surface resident lifetime on AlN surfaces indicate that the Al desorption energy is 3.0 eV.

Original languageEnglish (US)
Pages (from-to)244-248
Number of pages5
JournalMaterials Science and Engineering B: Solid-State Materials for Advanced Technology
Volume87
Issue number3
DOIs
StatePublished - Dec 19 2001

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Keywords

  • AlN surfaces
  • Rate of cation desorption
  • Rate of decomposition

ASJC Scopus subject areas

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

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