Hall electron mobility versus N spatial distribution in III-V-N systems

We have investigated nitrogen- (N-) induced scatterings in GaAsN, AlGaAsN and InGaAsN systems by conventional parameter fitting analysis for temperature dependence of Hall electron mobility. It has been revealed that the temperature dependence of the Hall electron mobility of GaAsN and AlGaAsN are completely different in low-temperature range below 200 K, and an influence by an unknown scattering mechanism induced by N incorporation in GaAsN is considerably larger than that in AlGaAsN, in spite of the fact that lattice mismatches of the two systems are almost equal. The results strongly indicate that an inhomogeneous N spatial distribution in GaAsN is closely related with increase of the unknown scattering contribution induced by N incorporation. Temperature dependence of the Hall electron mobility and N-induced scattering contribution in InGaAsN show a tendency similar to those in the AlGaAsN, because of the preferential bond formation of In-N bonds during InGaAsN growth. The results strongly suggest that N atoms should be bonded with In atoms preferentially such as In(4)N clusters and such clusters distributed randomly in order to compensate the strong local strain induced by N incorporation for the high-quality InGaAsN growth. (c) 2005 Elsevier B.V. All rights reserved.