Enhanced operation and retention characteristics in charge-trapping flash memory device with a novel Si/Ge super-lattice channel

Charge-trapping flash memory devices with super-lattice channels having different stacking structures and thicknesses of Ge top-layer are investigated in this work. Both programming and erasing speeds are significantly improved for devices with super-lattice channels. Programming speed increases with increasing thickness of Ge layer in the super-lattice channel. The enhancement on programming speed can be achieved up to 40 times or better. For devices with Ge top-layer on super-lattice channel, a further enhancement is observed with increasing Ge thickness. The retention characteristic of devices with super-lattice channel is better than that with Si-channel devices owing to the slightly increased thickness of tunneling oxide.