(Invited) First Principles and Themodynamical Studies on Matel Organic Vaper Phase Epitaxy of GaN

We analyzed metal organic vapor phase epitaxy growth mechanism of III-nitride semiconductors, GaN, AlN and InN based on first-principles calculations and thermodynamic analysis. With this calculated methods, we investigate the decomposition process of the group III source gases, X(CH 3 ) 3 (X = Ga, Al, In) at finite temperatures and whether the (CH 3 ) 2 GaNH 2 adduct can be formed or not. Our calculated results show that (CH 3 ) 2 GaNH 2 adduct cannot be formed in the gas phase reaction in GaN MOVPE. Whereas, (CH 3 ) 2 AlNH 2 adduct can be formed so much in gas phase in AlN MOVPE. In case of GaN MOVPE, trimethylgallium (TMG, [Ga(CH 3 ) 3 ]) almost decomposes into Ga gas on growth surface by the assistance of H 2 carrier gas instead of (CH 3 ) 2 GaNH 2 adduct formation. Moreover, in case of InN MOVPE, (CH 3 ) 2 InNH 2 adduct formation cannot occur and it is relatively easy that In gas is produced even if there is no H 2 carrier gas.