Cleanrooms and equipment

In 300 mm wafer fabs, which system automatically transports FOUPs between tools along rails on the ceiling?

  1. AManual cart transport
  2. BTransport by conveyor belts only
  3. COHT (overhead hoist transport)
Show answer and explanation

Answer: C. OHT (overhead hoist transport)

A FOUP holding 25 300 mm wafers is heavy, so manual transport is a heavy burden and carries risks of particle generation and dropping. An OHT is a vehicle running on ceiling rails that hangs FOUPs and automatically carries them to equipment load ports. It is the core of the fab-wide automated material handling system (AMHS).

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More Cleanrooms and equipment questions

  1. Which facility at a cleanroom entrance blows strong jets of clean air at workers to remove dust from the surface of their clothing?
  2. What is the main reason temperature is held extremely constant in cleanrooms, especially in exposure areas?
  3. What is used with precision equipment such as exposure tools to suppress the effects of vibration transmitted from the floor?
  4. Which device supplies ions to the air in a cleanroom to neutralize charge on wafers and equipment?
  5. Which unit at the front of process equipment opens FOUP doors and transfers wafers into the equipment while keeping them in a clean environment?