Reversible creation and annihilation of a local leakage path in HfO ₂/GeO_x stacked gate dielectrics: A direct observation by ultrahigh vacuum conducting atomic force microscopy

By direct observation using ultrahigh vacuum conducting atomic force microscopy, it is found that a local leakage path in Hf O2 Ge Ox stacks created by an electrical stress with a positive tip bias annihilates after applying a reverse tip bias. The creation and annihilation of these paths are repeatable without noticeable degradation. The fact that these paths annihilate by a very small reverse bias suggests that this behavior is caused by local reduction and oxidation in the Hf O2 layer.