Properties of a Nitrogen-Related Hole Trap Acceptor-Like State in p-Type GaAsN Grown by Chemical Beam Epitaxy

The properties of a nitrogen (N)-related hole trap HC2, located approximately 0.15 eV above the valence band maximum of GaAsN, and their relationship with the density of ionized acceptors (N(A)) in p-type GaAsN grown by chemical beam epitaxy are investigated using deep level transient spectroscopy and on the basis of the temperature dependence of the junction capacitance. At room temperature, N(A) is found to show a linear dependence on N concentration under N- and H-rich growth conditions. Furthermore, a N-dependent sigmoid increase in junction capacitance is observed in a specific temperature range from 70 to 100 K, which is the same as in the case where HC2 is recorded. Such behavior is explained by the thermal ionization of HC2, whose density affects in great part the magnitude order of N(A), essentially for a N concentration higher than 0.15%. Concerning its origin, HC2 is strongly considered to act as N-H related acceptor state. (C) 2010 The Japan Society of Applied Physics DOI: 10.1143/JJAP.49.121001