Power semiconductors

Which is a known challenge of SiC MOSFETs?

  1. ATheir breakdown voltage is lower than silicon's
  2. BTheir band gap is smaller than silicon's
  3. CThe interface between SiC and the gate oxide has many defects, so channel mobility tends to be low
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Answer: C. The interface between SiC and the gate oxide has many defects, so channel mobility tends to be low

SiC can also form SiO2 by thermal oxidation, but many defects, including carbon-related ones, tend to remain at the interface, making channel mobility much lower than the mobility inside the SiC crystal. Improvements have been made through interface nitridation and other treatments. Long-term reliability of the gate oxide is also an important evaluation item.

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More Power semiconductors questions

  1. In SiC power modules operating at high temperatures, which material is sometimes used instead of solder to bond the chips?
  2. What is the main advantage of raising the switching frequency of a power converter?
  3. In a power device gate drive circuit, what is the effect of increasing the gate resistance?
  4. Which metric indicates how long a power device can withstand a short circuit, such as both upper and lower switches of an inverter turning on at once, without being destroyed?
  5. What is the purpose of providing a short period in which both switches are off (dead time) when switching the upper and lower switches of an inverter?