Advanced transistors (FinFET and GAA)

Which correctly describes the transistor performance metric "Ion/Ioff ratio"?

  1. AThe ratio of on-state current to off-state leakage current; the larger, the better the switch
  2. BThe ratio of gate length to gate width
  3. CThe ratio of supply voltage to threshold voltage
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Answer: A. The ratio of on-state current to off-state leakage current; the larger, the better the switch

The Ion/Ioff ratio is the current flowing when a transistor is on divided by the leakage current when it is off. The larger it is, the better the switch: fast in operation with little standby leakage. As scaling strengthens short-channel effects, Ioff rises and the ratio falls, which is why FinFETs and GAA strengthen gate control.

  • A. Correct. It is the ratio of on-current to off-current.
  • B. It is not a ratio of dimensions.
  • C. It is not a ratio of voltages.
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More Advanced transistors (FinFET and GAA) questions

  1. How did the subthreshold swing (SS) generally change with the move from planar transistors to FinFETs?
  2. As physical scaling becomes harder, what is the practice of considering design and process technology together to optimize area and performance called?
  3. In nanosheet GAA transistors now in production, how many nanosheets are typically stacked in one transistor?
  4. Which structure places nMOS and pMOS nanosheets close together on either side of a thin insulating wall to reduce cell area?
  5. What is the state called in which the channel is so short that carriers travel from source to drain almost without scattering?