Title :
Charge Transport and Degradation in HfO2 and HfOx Dielectrics
Author :
Padovani, A. ; Larcher, Luca ; Bersuker, Gennadi ; Pavan, Paolo
Author_Institution :
Dipt. di Sci. e Metodi dell´Ing., Univ. di Modena e Reggio Emilia, Reggio Emilia, Italy
Abstract :
We combine experiments and simulations to investigate leakage current and breakdown (BD) in stoichiometric and sub-stoichiometric hafnium oxides. Using charge-transport simulations based on phonon-assisted carrier tunneling between trap sites, we demonstrate that higher currents generally observed in HfOx are due to a higher density of the as-grown oxygen vacancy defects assisting the charge transport. Reduction of the dielectric BD field (EBD) in HfOx is explained by the lower zero-field activation energy (EA,G) of the defect generation process, as extracted from time-dependent dielectric BD experiments.
Keywords :
charge exchange; crystal defects; dielectric devices; hafnium compounds; leakage currents; semiconductor device breakdown; stoichiometry; tunnelling; vacancies (crystal); EBD; HfO2; HfOx; as-grown oxygen vacancy defects; charge transport; charge-transport simulations; defect generation process; degradation; dielectric BD field; dielectrics; leakage current and breakdown; phonon-assisted carrier tunneling; substoichiometric hafnium oxides; time-dependent dielectric BD experiments; trap sites; zero-field activation energy; ${rm HfO}_{2}$ ; device physics; dielectric breakdown; oxygen vacancies; random access memory (RRAM); resistive switching memories; stoichiometry; time-dependent dielectric breakdown (TDDB); trap-assisted tunneling;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2251602
