MOSFET

In a MOS structure on a p-type substrate, what is the state of the semiconductor surface when a negative voltage is applied to the gate?

  1. AInversion, with electrons gathered
  2. BAccumulation, with holes gathered
  3. CA complete vacuum with no carriers
Show answer and explanation

Answer: B. Accumulation, with holes gathered

Applying a negative gate voltage to a MOS structure on a p-type substrate attracts the majority carriers, holes, to the surface, creating accumulation. As a positive voltage is applied and increased, the surface passes through depletion, with holes pushed away, and then at higher voltage reaches inversion, with electrons gathered.

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