Charge Trap Flash (CTF) is a technology for memory cells, comparable to the floating gate. The advantage of this technology is that the individual memory cells of the CTF memory do not influence each other, as is the case with the floating gate memory, and that a higher memory density
can be achieved with CTF technology.
In terms ofstructure, CTF technology is similar to floating gate technology, with only the floating gate being replaced by the charge traplayer. The electrons and electron holes are held on the charge trap layer made of silicon nitride
. This layer is separated from the silicon substrate by a thin oxide layer, the tunnel oxide. Since the control gate has a higher positive potential, the electrons reach the charge trap layer via thechannel
between drain and source and via the tunnel oxide layer, from where they cannot flow away. CTF technology is mainly used for NAND flashes.