Hydrogen at the Si/SiO2 interface: From atomic-scale calculations to engineering models

S. N. Rashkeev, D. M. Fleetwood, R. D. Schrimpf, S. T. Pantelides

Research output: Contribution to journalArticle

Abstract

Two contrasting behaviors have been observed for H in Si/SiO2 structures: a) Radiation experiments established that protons released in SiO2 migrate to the Si/SiO2 interface where they induce new defects; b) For oxides exposed first to high-temperature annealing and then to molecular hydrogen, mobile positive charge believed to be protons can be cycled to and from the interface by reversing the oxide electric field. First-principles density functional calculations identify the atomic-scale mechanisms for the two types of behavior and conditions that are necessary for each. Using the results of the atomic-scale calculations we develop a model for enhanced interface-trap formation at low dose rates due to space charge effects in the base oxides of bipolar devices. We find that the hole trapping in the oxide cannot be responsible for all the Enhanced Low-Dose-Rate Sensitivity (ELDRS) effects in SiO2, and the contribution of protons is also essential. The dynamics of interface-trap formation are defined by the relation between the proton mobility (transport time of the protons across the oxide) and the time required for positive-charge buildup near the interface due to trapped holes. The analytically estimated and numerically calculated interface-trap densities are found to be in very good agreement with available experimental data.

Original languageEnglish
Pages (from-to)575-580
Number of pages6
JournalInternational Journal of High Speed Electronics and Systems
Volume14
Issue number2
DOIs
Publication statusPublished - 1 Jun 2004

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Keywords

  • Bipolar transistors
  • Interface phenomena
  • Radiation effects
  • Space technology

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Hardware and Architecture
  • Electrical and Electronic Engineering

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