Current-voltage characteristic of alumina and aluminum nitride with or without electron irradiation

The current-voltage (I-V) characteristics of single- and poly-crystal alumi na and aluminum nitride CAIN) were measured at temperatures ranging from ro om temperature to 723 K with or without 1 MeV electron irradiation in a hig h voltage electron microscope (HVEM). Both alumina and AlN specimens exhibi t non-ohmic I-V characteristics without irradiation. The I-V characteristic s in alumina, however, change from non-ohmic to almost ohmic under electron irradiation. But the I-V characteristics in AlN is still non-ohmic under i rradiation. There are remarkable differences in I-V characteristics between the alumina and AlN specimens. The non-ohmic behavior is due to the electr onic barrier formed near the interface between the titanium electrode and t he alumina or AlN specimen. No bulk and surface radiation induced electrica l degradation (RIED) was found in AlN up to 1.5 x 10(-5) dpa. (C) 2000 Else vier Science B.V. All rights reserved.