Growth kinetics of AlGaN films by plasma-assisted molecular-beam epitaxy

In this letter, we report on the kinetics of growth of aluminum gallium nitride films by rf plasma-assisted molecular-beam epitaxy on (0001) sapphire substrates at the temperature range of 750–800 °C. The determination of the incorporation probabilities of aluminum and gallium atoms was arrived at by measurements of the growth rate and composition of the films. We find that, in both the nitrogen-rich and group-III-rich growth regimes, the incorporation probability of aluminum is unity for the entire investigated temperature range. On the other hand, the incorporation probability of gallium is constant and equals 0.75 at a substrate temperature of 750 °C only in the nitrogen-rich growth regime. The temperature dependence of the incorporation probability in this regime has an activation energy of 2.88 eV which is consistent with gallium desorption from the surface. In the group-III-rich growth regime, the incorporation probability of gallium decreases monotonically with group-III fluxes due to the competiti...

[1]  P. Hacke,et al.  Monitoring surface stoichiometry with the (2×2) reconstruction during growth of hexagonal‐phase GaN by molecular beam epitaxy , 1996 .

[2]  K. Ebeling,et al.  Fundamentals, material properties and device performances in GaN MBE using on-surface cracking of ammonia , 1997 .

[3]  Jong-hee Kim,et al.  Al concentration control of epitaxial AlGaN alloys and interface control of GaN/AlGaN quantum well structures , 2000 .

[4]  James S. Speck,et al.  Control of GaN surface morphologies using plasma-assisted molecular beam epitaxy , 2000 .

[5]  Yang,et al.  Surface kinetics of zinc-blende (001) GaN. , 1996, Physical review. B, Condensed matter.

[6]  R. Kaspi,et al.  The effect of Al on Ga desorption during gas source-molecular beam epitaxial growth of AlGaN , 1998 .

[7]  K. Evans,et al.  Growth kinetics of GaN grown by gas-source molecular beam epitaxy , 1997 .

[8]  K. Evans,et al.  Gallium incorporation kinetics during gas source molecular beam epitaxy growth of GaN , 1997 .

[9]  C. T. Foxon,et al.  Molecular beam epitaxy growth kinetics for group III nitrides , 1996 .

[10]  A. M. Johnston,et al.  Growth rate reduction of GaN due to Ga surface accumulation , 1996 .

[11]  Walter A. Harrison,et al.  Electronic structure and the properties of solids , 1980 .

[12]  S. Chu,et al.  Epitaxial growth and self-organized superlattice structures in AlGaN films grown by plasma assisted molecular beam epitaxy , 2001 .

[13]  Jörg Neugebauer,et al.  Structure of GaN(0001): The laterally contracted Ga bilayer model , 2000 .