Oxidation and diffusion

What is the phenomenon called in which boron and phosphorus diffuse faster during silicon oxidation than without oxidation?

  1. AElectromigration
  2. BChanneling
  3. COxidation-enhanced diffusion (OED)
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Answer: C. Oxidation-enhanced diffusion (OED)

As oxidation proceeds, excess silicon interstitials at the interface are injected into the silicon. Boron and phosphorus diffuse readily by pairing with silicon interstitials, so their diffusion speeds up during oxidation. This is called oxidation-enhanced diffusion (OED). Antimony, which diffuses via vacancies, conversely slows down during oxidation.

  • A. Electromigration is the movement of wiring metal atoms caused by current.
  • B. Channeling is ions traveling deep along crystal channels during implantation.
  • C. Correct. Interstitials injected by oxidation speed up diffusion.
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More Oxidation and diffusion questions

  1. When thin oxides of a few tens of nanometers or less are grown by dry oxidation, which known deviation from the Deal-Grove model occurs?
  2. In LOCOS, what is the phenomenon called in which a thin nitride forms on the silicon surface under the nitride mask, later causing the gate oxide there to be locally thin or defective?
  3. Why does the compressive stress in thermally grown oxide become smaller when oxidation is done above about 950 °C?
  4. Why can SiO2 serve as a diffusion mask against boron and phosphorus but works poorly as a mask against gallium and aluminum?
  5. In regions where the impurity concentration far exceeds the intrinsic carrier density, the diffusion coefficient of arsenic and others varies with concentration. Which statement about this is correct?