Grown-in stress and subsequent fracture in AlxGa1-xN/GaN heterostructures with or without impurity doping were studied in situ. It was found that the critical thickness of AlxGa1-xN depends not only on its composition but also on the concentration of impurities such as Si or Mg. Increase in tensile stress during growth at a constant AlN molar fraction can be explained by the increase in the biaxial modulus of AlxGa1-xN due to impurity doping.
Japanese Journal of Applied Physics
- Pub Date:
- March 2001