Deep levels in the upper bandhyphen;gap region of lightly Mghyphen;doped GaN

摘要

Deep levels in undoped and weakly Mghyphen;dopednhyphen;type GaN films fabricated by metalorganic chemical vapor deposition were examined with deep level transient spectroscopy. Deep levels measured at 0.26 and 0.62 eV below the conduction band were found in relatively low concentrations of sim;2times;1013cmminus;3in undoped GaN. Addition of small quantities of the Mg acceptor species by means of bishyphen;cyclopentadienyl magnesium (Cp2Mg) during growth corresponded to a significant increase in the concentration of the level at 0.62 eV. The concentration of the shallower level, found to be independent of the Cp2Mg addition, remained unchanged. These deep levels may detrimentally affect optical and electrical properties when fabricatingphyphen;type GaN. copy;1996 American Institute of Physics.