Electrical conductivity of In₂O₃ and Ga₂O₃ after low temperature ion irradiation; implications for instrinsic defect formation and charge neutrality level.

The evolution of sheet resistance of n-type In2O3 and Ga2O3 exposed to bombardment with MeV
 12C and 28Si ions at 35 K is studied in situ. While the sheet resistance of Ga2O3 increased by
 more than 8 orders of magnitude as a result of ion irradiation, In2O3 showed a more complex defect
 evolution and became more conductive when irradiated at the highest doses. Heating up to room
 temperature reduced the sheet resistivity somewhat, but Ga2O3 remained highly resistive, while
 In2O3 showed a lower resistance than as deposited samples. Thermal admittance spectroscopy and
 deep level transient spectroscopy did not reveal new defect levels for irradiation up to 2 1012
 cm2. A model where larger defect complexes preferentially produce donor like defects in In2O3
 is proposed, and may reveal a microscopic view of a charge neutrality level within the conduction
 band, as previously proposed.