Evidence for hole and electron trapping in plasma deposited ZrO2 thin films

We have observed electron and hole trapping phenomena in thin films of ZrO2 obtained by plasma assisted deposition. Limited thickness dependent measurements suggest that the holes are trapped uniformly through the film while the electrons trap at the ZrO2/Si interface. Relaxation of the trapped holes occurs rapidly after removal of negative stress (similar to 90% in 15 min), while electron relaxation postpositive stress occurs more slowly (similar to 10% in 100 min). Cycling between states of positive trapped charge and negative trapped charge by application of the appropriate stressing voltage was observed. (C) 2001 American Institute of Physics.