Deep electron traps in HfO2-based metal-oxide-semiconductor capacitors

SAMBUCO SALOMONE, L.; LIPOVETZKY, J.; CARBONETTO, S.; GARCIA INZA, M.; REDIN, E. G.; CAMPABADAL, F.; FAIGON, A.

THIN SOLID FILMS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2016 vol. 600 p. 36 - 42

0040-6090

Hafnium oxide (HfO 2 ) is currently considered to be a good candidate to take part as a component in charge-trapping nonvolatile memories. In this work, the electric field and time dependences of the electron trapping/detrapping processes are studied through a constant capacitance voltage transient technique on metal-oxide-semiconductor capacitors with atomic layer deposited HfO 2 as insulating layer. A tunneling-based model is proposed to reproduce the experimental results, obtaining fair agreement between experiments and simulations. From the fitting procedure, a band of defects is identified, located in the first 1.7 nm from the Si/HfO 2 interface at an energy level E t = 1.59 eV below the HfO 2 conduction band edge with density N t = 1.36 × 10 19 cm −3 . A simplified analytical version of the model is proposed in order to ease the fitting procedure for the low applied voltage case considered in this work.