Epitaxial growth

In silicon epitaxial growth, what is the main role of the large flow of hydrogen (H2) supplied along with the source gas?

  1. AIt is the silicon source itself
  2. BIt is the n-type dopant
  3. CIt is a carrier gas for the source and provides a reducing atmosphere that keeps the surface clean
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Answer: C. It is a carrier gas for the source and provides a reducing atmosphere that keeps the surface clean

In silicon epitaxy, source gases such as trichlorosilane are diluted with hydrogen and fed into the reactor. Hydrogen acts as a carrier gas for the source, prevents surface oxidation through its reducing atmosphere, and also carries away chlorine produced by the reaction as hydrogen chloride.

  • A. Silicon sources are silane and chlorosilanes.
  • B. Phosphine and the like are used as n-type dopants.
  • C. Correct. It is used as a carrier gas.
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More Epitaxial growth questions

  1. Which method is used to grow thick GaN layers quickly to make free-standing GaN substrates?
  2. Which is closest to the density of threading dislocations, which run up to the film surface, in GaN grown on sapphire?
  3. In bipolar transistors and similar devices, what is the main purpose of a heavily doped layer (buried layer) beneath the epitaxial layer?
  4. Which is closest to the typical growth temperature for SiC epitaxy (CVD)?
  5. Which type of reactor is mainstream for silicon epitaxial growth on 300 mm wafers?