Source electrode Control gate electrode Select gate electrode Drain electrode
CG
SG
FG
Thin oxide film
UTO
N+
N+
N+
P substrate
GND
[Data rewrite]
Data rewrite refers to the injection or removal of electrons into or from the FG. In this process, electrons
pass through a thin oxide film (UTO). The oxide film inherently acts as an insulator, but in this case the
film conducts electricity (electrons are transferred).
[Data retention]
Data retention refers to the prevention of leakage of electrons stored in the FG. This must be assured
for at least 10 years.
To meet the above stated contradictory properties, high-quality thin oxide films (UTO) must be
manufactured. Such UTOs are very thin (on the order of 10 nm), and stably manufacturing them
requires a very difficult technique.
<Remarks>
FAQ No.: 12022
28
SII [ SEIKO INSTRUMENTS INC ]
