Compound semiconductors

What is one main reason SiC is used as the substrate for GaN HEMTs?

  1. AIt is cheaper than silicon
  2. BIt does not transmit light
  3. CIts high thermal conductivity makes it easy to remove heat from the device
Show answer and explanation

Answer: C. Its high thermal conductivity makes it easy to remove heat from the device

High-power GaN HEMTs generate a lot of heat, and performance and reliability fall as temperature rises. SiC has high thermal conductivity and a relatively small lattice mismatch with GaN, so it is used as the substrate for high-frequency, high-power GaN HEMTs. Si substrates are also used where cost is a priority.

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More Compound semiconductors questions

  1. Which material is mainly used in the light-emitting layer of deep-ultraviolet LEDs, such as those for sterilization?
  2. Which is a characteristic of multi-junction solar cells, which stack several compound semiconductor layers with different band gaps?
  3. Which impurity is typically used to make p-type layers in GaN?
  4. What is the typical crystal structure of GaN?
  5. Which is an example of an application of HBTs (heterojunction bipolar transistors) made from InP or GaAs?