Stress development in plasma-deposited silicon dioxide thin-films due to hydrogen evolution

Sathya Mani, Taher Saif

Research output: Contribution to journalArticle

Abstract

The kinetics of stress change in plasma-enhanced chemical vapor deposited (PECVD) silicon dioxide dielectric films, during annealing, is studied. When silicon dioxide is deposited in excess nitrous oxide, a fraction of the oxide is in the form SiO3/2OH, instead of SiO2, which on annealing condenses to SiO2 and H2O. The condensed water subsequently diffuses out of the film inducing a stress change (increase in tension or decrease in compression) in the film. A theoretical model relating the hydrogen (or water) concentration to the stress change is developed. Secondary ion mass spectrometry analysis revealed a relatively flat hydrogen concentration profile along the thickness of the film, indicating that the stress change is not diffusion limited. The model thus accounts for first order kinetics for bond breaking accompanied by fast diffusion with a fraction of the atoms or molecules undergoing a trap and release process. From the theoretical fit for the experimental data, activation energy of 1.1 eV for bond breaking is obtained. The model allows predicting the time dependent stress evolution in the PECVD film subjected to a prescribed temperature history.

Original languageEnglish (US)
Pages (from-to)3120-3125
Number of pages6
JournalThin Solid Films
Volume515
Issue number5
DOIs
StatePublished - Jan 22 2007

Keywords

  • Dielectric
  • Hydrogen
  • Plasma
  • Stress

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Stress development in plasma-deposited silicon dioxide thin-films due to hydrogen evolution'. Together they form a unique fingerprint.

  • Cite this