Title :
Two-Pulse
–
: A New Method for Characterizing Electron Traps in the Bulk of
Author :
Zhang, W.D. ; Govoreanu, B. ; Zheng, X.F. ; Aguado, D. Ruiz ; Rosmeulen, M. ; Blomme, P. ; Zhang, J.F. ; Houdt, J. Van
Author_Institution :
Sch. of Eng., Liverpool John Moores Univ., Liverpool
Abstract :
SiO2/high-kappa dielectric stack is a candidate for replacing the conventional SiO2-based dielectric stacks for future Flash memory cells. Electron traps in the high-kappa layer can limit the memory retention via the trap-assisted tunneling, and there is a pressing need for their characterization. A new two-pulse C -V measurement technique is developed in this letter, which, for the first time, allows us to probe the discharge of electron traps throughout the SiO2/high-kappa stack. It complements the charge pumping technique, which can only probe near-interface traps. It is demonstrated that a large number of electron traps, indeed, exist in the bulk of high-kappa layer. Bulk electron traps also have different discharge characteristics from those near the SiO2/high-kappa interface.
Keywords :
alumina; capacitance measurement; electron traps; flash memories; high-k dielectric thin films; silicon compounds; voltage measurement; SiO2-Al2O3; SiO2/high-kappa dielectric stacks; charge pumping; discharge characteristics; electron traps; flash memory; two-pulse C-V measurement technique; Aluminum oxide; Charge pumps; Dielectric measurements; Electron traps; Flash memory; Flash memory cells; Nonvolatile memory; Pressing; Probes; Tunneling; $hbox{Al}_{2}hbox{O}_{3}$; Flash memory; electron trap; energy distribution; floating gate; high-$kappa$ dielectrics; interpoly dielectric (IPD) layer; pulsed $C$ –$V$;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2008.2001234