CMP and cleaning

What is the main purpose of cleaning the back and edge (bevel) of wafers?

  1. ATo make the wafer lighter
  2. BTo prevent contamination and particles on the back and edge from transferring to equipment, other wafers or the front surface
  3. CTo make the wafer shine
Show answer and explanation

Answer: B. To prevent contamination and particles on the back and edge from transferring to equipment, other wafers or the front surface

Contamination on the back and edge of wafers spreads to other wafers through equipment stages, handling parts and FOUPs, or flakes off onto the front surface. Films at the edge flake off especially easily, so bevel films are removed and cleaned to prevent contamination from spreading.

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More CMP and cleaning questions

  1. What is the main reason wafer cleaning is considered important in semiconductor manufacturing?
  2. Which correctly describes how many times cleaning is performed across the whole LSI manufacturing flow?
  3. Which set correctly lists the kinds of surface contamination removed from wafers by cleaning?
  4. In processes such as multilevel wiring, what is the main reason the wafer surface must be planarized by CMP?
  5. Which correctly describes the basic configuration of a CMP tool?