Hole trapping in HfO2 insulators on Si(100)

Hole trapping in insulating layers of HfO2 grown on Si(I 00) using different deposition methods is analysed by generating electron-hole pairs in the oxide and observing the stable trapped charge. The charge trapping appears to be strongly sensitive to the chemistry of the particular deposition method. The dependence of the trapped charge density on the HfO2 thickness indicates the hole trapping to be predominantly associated with a SiO2-like interlayer formed between Si and HfO2 during the deposition process or subsequent annealing. The diamagnetic nature of the positively charge centers in combination with the observed correlation between the positive charge and the release of atomic hydrogen at the Si/oxide interface suggest that the positive charge may be related to protonic species. (C) 2004 Elsevier B.V. All rights reserved.