Silicon wafers

What is the purpose of the laser mark (ID mark) inscribed on the front or back of a wafer?

  1. ATo decorate the wafer
  2. BTo strengthen the wafer
  3. CTo identify each wafer so its process history can be traced
Show answer and explanation

Answer: C. To identify each wafer so its process history can be traced

A unique number or similar is laser-inscribed on each wafer. Equipment reads it to identify the wafer and record which tools processed it and under what conditions. This helps trace back the responsible process or tool when defects are found.

Practice this topic Back to topic

More Silicon wafers questions

  1. Which polishing method is common for 300 mm wafers?
  2. What is a used monitor wafer called after its surface films are removed and it is repolished for reuse?
  3. Which method is used to measure wafer resistivity without contact?
  4. Which method irradiates FZ silicon with neutrons to convert some silicon into phosphorus, making it uniformly n-type?
  5. Which method applies a magnetic field to the crucible in the CZ method to suppress melt convection and control oxygen concentration and other properties?