Title :
Understanding of Trap-Assisted Tunneling Current - Assisted by Oxygen Vacancies in RuOx/SrTiO3/TiN MIM Capacitor for the DRAM Application
Author :
Kim, M.-S. ; Kaczer, B. ; Starschich, S. ; Popovici, M. ; Swerts, J. ; Richard, O. ; Tomida, K. ; Vrancken, C. ; Van Elshocht, S. ; Debusschere, I. ; Altimime, L. ; Kittl, J.A.
Author_Institution :
imec, Leuven, Belgium
Abstract :
A transient leakage current was measured as a function of time for thin (~9 nm) strontium titanate (STO) capacitor dielectrics with RuOx as a bottom electrode and TiN as a top electrode at different temperatures under constant direct current (DC) bias stress. With the space-charge-limited (SCL) current theory, the mobility of oxygen vacancies (VO) and the activation energy (E0) of VO were extracted. By closely examining the time-zero current-voltage (I-V) curves for a positively and a negatively held DC bias conditions before and after the stresses, an understanding of trap-assisted-tunneling (TAT) current, initiated by oxygen vacancies (VO) is presented. Based on this understanding, a way to further reduce the leakage current for a sub-10 nm dielectric film is provided.
Keywords :
DRAM chips; MIM devices; capacitors; electrodes; ruthenium compounds; strontium compounds; titanium compounds; DC bias conditions; DRAM Application; MIM capacitor; RuOx-SrTiO3-TiN; SCL current theory; TAT current; dielectric film; oxygen vacancies; size 10 nm; space-charge-limited current theory; strontium titanate capacitor dielectrics; time-zero current-voltage curves; transient leakage current; trap-assisted tunneling current assisted; trap-assisted-tunneling current; Capacitors; Leakage current; MIM capacitors; Stress; Tin; Transient analysis;
Conference_Titel :
Memory Workshop (IMW), 2012 4th IEEE International
Conference_Location :
Milan
Print_ISBN :
978-1-4673-1079-6
DOI :
10.1109/IMW.2012.6213661
