Epitaxial growth

In SiC epitaxial growth, what is the main reason for using substrates tilted a few degrees from the crystal axis (with an off-angle)?

  1. ATo grow laterally from atomic steps on the surface (step-flow growth) and inherit the same polytype as the substrate
  2. BTo make the substrate cheaper
  3. CTo make the growth rate zero
Show answer and explanation

Answer: A. To grow laterally from atomic steps on the surface (step-flow growth) and inherit the same polytype as the substrate

SiC has many polytypes that differ in how atoms stack. An off-angle substrate has many atomic steps on its surface, and growth proceeds laterally from them, so the crystal inherits the same stacking as the substrate (such as 4H-SiC).

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More Epitaxial growth questions

  1. Which is an advantage of performing silicon epitaxial growth at reduced pressure?
  2. Which method measures the thickness of a lightly doped epitaxial layer on a heavily doped substrate using infrared interference?
  3. What is the main challenge in growing GaN on Si substrates?
  4. What is it called when doping gas is flowed during epitaxial growth to add dopants at the same time as growth?
  5. What is the periodic structure called in which layers of different materials, each only a few nm thick, are stacked alternately?