Silicon wafers

Heat treatment of a wafer diffuses oxygen out from near the surface, creating a low-defect layer at the surface where devices are made. What is this layer called?

  1. ABuried oxide (BOX) layer
  2. BDZ (denuded zone)
  3. CLDD
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Answer: B. DZ (denuded zone)

High-temperature heat treatment drives oxygen out from near the surface, forming a denuded zone (DZ) free of oxygen precipitates at the surface and a gettering layer of precipitates inside. Devices are built in the defect-free surface while metal contamination is captured inside.

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More Silicon wafers questions

  1. What is the purpose of the laser mark (ID mark) inscribed on the front or back of a wafer?
  2. Which polishing method is common for 300 mm wafers?
  3. What is a used monitor wafer called after its surface films are removed and it is repolished for reuse?
  4. Which method is used to measure wafer resistivity without contact?
  5. Which method irradiates FZ silicon with neutrons to convert some silicon into phosphorus, making it uniformly n-type?