Title :
Charge Retention Loss in a HfO2 Dot Flash Memory via Thermally Assisted Tunneling
Author :
Wang, Tahui ; Ma, H.C. ; Li, C.H. ; Lin, Y.H. ; Chien, C.H. ; Lei, T.F.
Author_Institution :
Nat. Chiao-Tung Univ., Hsinchu
Abstract :
The charge loss mechanism in a hafnium oxide (HfO2 ) dielectric dot flash memory is investigated. We measure the temperature and time dependence of a charge loss induced gate leakage current in a large area cell directly. We find that (1) the charge loss is through a top oxide in the cell and (2) the stored charge emission process exhibits an Arrhenius relationship with temperature, as opposed to linear temperature dependence in a semiconductor-oxide-nitride-oxide-semiconductor flash memory. A thermally activated tunneling front model is proposed to account for the charge loss behavior in a HfO2 dot flash memory.
Keywords :
flash memories; hafnium compounds; high-k dielectric thin films; leakage currents; tunnelling; HfO2; HfO2 dot flash memory; charge retention loss; gate leakage current; hafnium oxide; tunneling; Area measurement; Charge measurement; Current measurement; Dielectric loss measurement; Dielectric losses; Dielectric measurements; Flash memory; Hafnium oxide; Temperature dependence; Temperature measurement; Charge retention loss; hafnium oxide $( hbox{HfO}_{2})$ dot flash; thermally activated tunneling;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2007.910785
