Abstract
We investigated deep-level traps formed in Al0.2 Ga0.8 N/GaN heterostructures grown using plasma-assisted molecular beam epitaxy and by performing deep level transient spectroscopy (DLTS). Two electron traps with activation energies of Ec-150 meV and Ec-250 meV were observed, and their capture cross-sections (σT) were estimated to be 2.0× 10-18 cm2 and 1.1× 10-17 cm2, respectively. Different behaviors in the dependence of DLTS on filling pulse length confirm that the traps originated from N vacancies and dislocations. The amplitude of the dislocation-induced DLTS signal was reduced significantly by high-temperature rapid thermal annealing under N2 ambient after hydrogen treatment due to the reduction in dislocation density.
Original language | English |
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Article number | 112110 |
Journal | Applied Physics Letters |
Volume | 97 |
Issue number | 11 |
DOIs | |
State | Published - 13 Sep 2010 |