Deposition (CVD and PVD)

Which is an example of the precursors used to deposit HfO2 gate dielectrics by ALD?

  1. ASilane and ammonia
  2. BTungsten hexafluoride and hydrogen
  3. CHafnium tetrachloride (HfCl4) or organohafnium compounds, with an oxidant such as water or ozone
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Answer: C. Hafnium tetrachloride (HfCl4) or organohafnium compounds, with an oxidant such as water or ozone

HfO2 ALD alternately supplies a hafnium source such as HfCl4 or TEMAHf and an oxidant such as H2O or O3, depositing one layer at a time by surface reactions. The choice of source changes the deposition temperature and film impurities (chlorine or carbon).

  • A. Silane and ammonia are sources for silicon nitride.
  • B. Tungsten hexafluoride and hydrogen are sources for tungsten CVD.
  • C. Correct. A hafnium source and an oxidant are supplied alternately.
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More Deposition (CVD and PVD) questions

  1. Which model organizes, by temperature and gas pressure, the tendency of sputtered metal films to form columnar grains with many voids at low deposition temperatures?
  2. In CVD, what is the phenomenon called in which more source gas is consumed and the deposition rate drops as the area of wafers or patterns being coated increases?
  3. In reactive sputtering, what is the phenomenon called in which, with too much reactive gas flow, the target surface becomes covered with a compound and the deposition rate drops sharply?
  4. Which method is used to tune the stress of plasma CVD silicon nitride from compressive to tensile?
  5. Into which category does deposition by sputtering fall?