Deposition (CVD and PVD)

Why has high-density plasma CVD (HDP-CVD) been used to fill narrow trenches with insulator?

  1. ABecause ion sputtering during deposition trims film at the openings, allowing filling with few voids
  2. BBecause the deposition temperature is high, over 1000 °C
  3. CBecause it can deposit only metal films
Show answer and explanation

Answer: A. Because ion sputtering during deposition trims film at the openings, allowing filling with few voids

When ordinary CVD fills narrow trenches, film builds up thickly at the corners of the opening and closes it first, sometimes leaving a void inside. HDP-CVD trims the film at the opening with ions while depositing, so trenches fill from the bottom up. It has been used to fill STI and gaps between wires.

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More Deposition (CVD and PVD) questions

  1. Which correctly describes uses of silicon nitride (Si3N4) films?
  2. What is the main purpose of placing magnets behind the target in magnetron sputtering?
  3. Under what condition does CVD give good step coverage (conformality)?
  4. When silicon films are deposited by thermally decomposing silane, what kind of film forms if the deposition temperature is lowered?
  5. Which is an example of a typical material deposited by ALD?