Interface traps and dangling-bond defects in (100)Ge∕HfO2

Abstract
Combined electrical and electron spin resonance analysis reveals dramatic differences in the interfacedefect properties of the ( 100 ) Ge ∕ Ge O x N y ∕ Hf O 2 and ( 100 ) Ge ∕ Ge O 2 interfaces from the seemingly similar interfaces of (100)Si with the Hf O 2 and Si O 2 . No dangling bond centers associated with Ge crystal surface atoms are detected. Only paramagneticdefects in the near-interfacial Ge oxide or Ge (oxy)nitride layers are observed. In contrast to the amphoteric traps related to the dangling bonds ( P b -type centers) commonly observed at the silicon/insulator interfaces, the major component of the Ge/insulator interface trap spectrum comes from slow acceptor states which show no correlation with paramagnetic centers and are resistant to passivation by hydrogen.