Power semiconductors

Which is a characteristic of a superjunction (SJ) MOSFET?

  1. AAlternating p-type and n-type pillars in the drift layer lower on-resistance while maintaining breakdown voltage
  2. BIt has two gates
  3. CThe gate oxide is made very thick to raise breakdown voltage
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Answer: A. Alternating p-type and n-type pillars in the drift layer lower on-resistance while maintaining breakdown voltage

In a superjunction structure, p-type and n-type pillars alternate in the drift layer. In the off state both are depleted, maintaining high breakdown voltage; in the on state, current flows through the heavily doped n-type pillars, giving on-resistance lower than the conventional breakdown-voltage/on-resistance trade-off allows.

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More Power semiconductors questions

  1. If a power device with a thermal resistance of 2 °C/W dissipates 10 W, what is the temperature rise?
  2. What is the parasitic diode that forms structurally inside a power MOSFET called?
  3. What is the general term for semiconductors with a larger band gap than silicon, such as SiC and GaN?
  4. What is the main role of a gate driver for power semiconductors?
  5. Why are power devices required to be 'normally off', with no current flowing at 0 V gate voltage?