CMP and cleaning

What is the main purpose of using IPA (isopropyl alcohol) when drying wafers after cleaning?

  1. ATo prevent watermarks (drying stains)
  2. BTo etch the wafer surface
  3. CTo oxidize the wafer surface
Show answer and explanation

Answer: A. To prevent watermarks (drying stains)

If water is left on the surface to dry naturally, dissolved substances remain and form watermarks. IPA mixes readily with water and has low surface tension, so it displaces water for rapid drying or pulls water away using differences in surface tension (the Marangoni effect), preventing stains.

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More CMP and cleaning questions

  1. Which method is used to detect the polishing endpoint in CMP?
  2. In Preston's equation for CMP removal rate, which quantity is the removal rate proportional to?
  3. Which abrasive particles are often used in STI CMP to achieve high polishing selectivity of oxide to silicon nitride?
  4. Which cleaning method applies MHz-range ultrasound to the cleaning solution to remove tiny particles from the wafer surface?
  5. What is the main purpose of cleaning with ozone dissolved in ultrapure water (ozonated water)?