Effect of hydrogen carrier gas on AlN and AlGaN growth in AMEC Prismo D-Blue® MOCVD platform

• AlN growth rate increases with the increase of hydrogen flow rate and confirmed by CFD simulation.
• Al related parasitic reactions can be suppressed at higher hydrogen flow rate.
• Al composition in AlGaN increases initially with the increase of hydrogen flow, then saturates.
• GaN partial growth rate in AlGaN shows a “U” shaped profile.

Effect of hydrogen flow rate on AlN and AlGaN growth is investigated in AMEC Prismo D-Blue® MOCVD platform. It is found that AlN growth rate increases with the increase of hydrogen flow rate. Al composition in AlGaN material increases initially with the increase of hydrogen flow rate at relatively low hydrogen flow rates (<120 slm) and then saturates at high hydrogen flow rates. GaN partial growth rate shows a “U” shaped profile. Computational fluid dynamics (CFD) simulation of AlN growth is performed to understand the growth mechanism. The simulation results indicate that higher hydrogen flow rate could suppress the parasitic reaction and particle formation during AlN growth. Thus more source gases can be transported to the wafer surface, resulting in the increase of AlN growth rate.