Process materials (gases and chemicals)

Which gas is used as the germanium source in SiGe epitaxial growth?

  1. AAmmonia (NH3)
  2. BGermane (GeH4)
  3. CArsine (AsH3)
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Answer: B. Germane (GeH4)

SiGe growth flows germane (GeH4) as the germanium source together with a silicon source such as silane or dichlorosilane. The ratio of their flows controls the Ge fraction. Germane is also a hydride and is handled carefully because it is toxic and flammable.

  • A. Ammonia is a nitrogen source used for nitride films and the like.
  • B. Correct. Germane is the germanium source.
  • C. Arsine is an arsenic source used for n-type doping and the like.
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