Kinetic-Thermodynamic Model For Carbon Incorporation During Step-Flow Growth Of Gan By Metalorganic Vapor Phase Epitaxy

Relationships between concentration of unintentionally doped carbon in GaN and its metalorganic vapor phase epitaxy conditions were investigated theoretically. A kinetic-thermodynamic model which considers kinetic behavior of adsorbed atoms on vicinal surface was proposed. Thermodynamic properties of gas species and adsorption energies obtained by first-principles calculation were used in the model. The predicted carbon concentration range, 10(15) similar to 10(17) cm(3), agreed with that of experimental results quantitatively. The calculation results also reproduced experimental tendency: Carbon concentration decreases with increase of NH3 partial pressure and total pressure and/or decrease of trimethylgallium partial pressure.