CMP and cleaning

To prevent fine structures from collapsing, which method removes native oxide and the like without using liquids?

  1. ABrush scrub cleaning
  2. BDry cleaning using vapor-phase gases or radicals
  3. CMegasonic cleaning
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Answer: B. Dry cleaning using vapor-phase gases or radicals

Tall, narrow patterns can collapse due to surface tension as cleaning liquid dries. Vapor-phase (dry) cleaning, using hydrogen fluoride vapor or plasma-generated radicals, uses no liquid, so there is no risk of pattern collapse, and it is used for surface treatment of fine structures.

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More CMP and cleaning questions

  1. Which combination correctly lists processes in which CMP is used?
  2. What is the operation called in which the surface of a CMP pad is dressed with a diamond tool to stabilize the removal rate?
  3. Compared with planarization by thermal reflow or etch-back, what is an advantage of CMP?
  4. Which correctly describes the order and purposes of SC-1 and SC-2 in standard RCA cleaning?
  5. What is the main cause of pattern collapse when cleaning and drying high-aspect-ratio patterns?