Process materials (gases and chemicals)

How are sources that are liquid at room temperature (such as TEOS) supplied as gas to CVD tools?

  1. AA carrier gas is bubbled through the liquid to carry its vapor (bubbling), or the liquid is vaporized in a vaporizer before supply
  2. BThe liquid is solidified and fed in as powder
  3. CThe liquid is poured directly into the reactor
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Answer: A. A carrier gas is bubbled through the liquid to carry its vapor (bubbling), or the liquid is vaporized in a vaporizer before supply

Liquid sources are sent to the reactor as gas either by bubbling a carrier gas through a temperature-controlled container to carry the vapor, or by metering the liquid flow and flash-vaporizing it in a vaporizer. The latter makes precise control of delivery easier.

  • A. Correct. It is vaporized by bubbling or a vaporizer before supply.
  • B. Feeding powder is not a common method.
  • C. Pouring in liquid would not give uniform deposition.
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More Process materials (gases and chemicals) questions

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  2. What degradation tends to occur when quartz parts in heat-treatment furnaces are used at high temperature for a long time?
  3. Why must gas piping be designed to minimize dead spaces, the stagnant pockets where gas does not flow?
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