Effect of the SiO2/Si interface on self-diffusion in SiO 2 upon oxidation

Masashi Uematsu, Kenzo Ibano, Kohei M. Itoh

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The effect of the SiO2/Si interface on Si self-diffusion in SiO2 during thermal oxidation was investigated using silicon isotopes. Samples with natSiO2/28Si heterostructures were oxidized at 1150 - 1250°C and the 30Si diffusion in 28SiO2 during the thermal oxidation was investigated by secondary ion mass spectrometry (SIMS) measurements. Near the SiO2/Si interface, a significant profile broadening of the 30Si isotope from natSiO2 toward the newly grown 28SiO2 was observed. This 30Si self-diffusivity sharply decreases with oxidation time and hence with increasing distance between 30Si diffusion region and the interface. This distance-dependent 30Si self-diffusion was simulated taking into account the effect of Si species generated at the interface upon oxidation and diffusing into SiO2 to enhance Si self-diffusion. The simulation fits the SIMS profiles and these results indicate that Si species, most likely SiO, are emitted from the SiO2/Si interface upon Si thermal oxidation to release the oxidation-induced stress, as has been predicted by recent theoretical studies. Furthermore, combined with our recent results on O self-diffusion, the diffusion behavior of the emitted SiO near the SiO 2/Si interface is discussed.

Original languageEnglish
Pages (from-to)685-692
Number of pages8
JournalDefect and Diffusion Forum
Publication statusPublished - 2008


  • Interface
  • Self-diffusion
  • Silicon dioxide
  • Thermal oxidation

ASJC Scopus subject areas

  • Radiation
  • General Materials Science
  • Condensed Matter Physics


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