Charge Retention Loss in a \hbox Dot Flash Memory via Thermally Assisted Tunneling

• Published in: IEEE electron device letters Vol. 29; no. 1; pp. 109 - 110
• Main Authors: Tahui Wang, Ma, H.C., Li, C.H., Lin, Y.H., Chien, C.H., Lei, T.F.
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2008
• Subjects: Area measurement; Charge measurement; Charge retention loss; Current measurement; Dielectric loss measurement; Dielectric losses; Dielectric measurements; Flash memory; Hafnium oxide; hafnium oxide ( \hbox{HfO}_{2}) dot flash; Temperature dependence; Temperature measurement; thermally activated tunneling
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2007.910785

The charge loss mechanism in a hafnium oxide (HfO 2 ) 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 HfO 2 dot flash memory.