▎ 摘　　要

NOVELTY - Non-volatile memory device (100) comprises tunnel oxide (21) for tunneling charges, data storage layer, blocking oxide (23), gate electrode (24) made of graphene, and metal electrode (25) for capping, which are sequentially formed on a channel region between the source/drain electrodes of a substrate. USE - Non-volatile memory device i.e. floating gate- or charge trap-type non-volatile memory device. ADVANTAGE - Graphene has a high work function and does not cause the deterioration of a lower insulating film, thus, remarkably improving the memory characteristics of non-volatile memory device and device reliability of MOSFET. When the gate electrode made of graphene having high work function is used, the energy level of the blocking oxide adjacent to the gate electrode becomes high. Thus, the electric field strength in the blocking oxide becomes low, and the tunneling distance, over which the electrons trapped or stored in the charge trap layer or charge storage layer are discharged through the blocking oxide, becomes long, so that it is possible to efficiently prevent the charges injected into the charge storage layer from being discharged to the gate electrode, improving the data retention characteristics of a memory device. In the case of the gate electrode made of graphene, compared to a general metal (tantalum nitride (TaN)) gate electrode, the number of defects formed in the blocking oxide can be remarkably reduced, so that the amount of the trap-assisted tunneling current discharged through the defects can be lowered, further improving the write operation speed and data retention characteristics of a memory device. The leakage current of non-volatile memory device including the gate electrode made of graphene is 1/102-1/103 lower than that of a conventional non-volatile memory device including TaN gate electrode in an operation voltage range (- 16 to - 22 V), and that the breakdown voltage of the non-volatile memory device is also increased compared to that of the conventional non-volatile memory device. When a conventional gate electrode made of TaN is used, data is not erased at a high erasing voltage, but when the gate electrode made of graphene is formed, improved memory window characteristics are exhibited without causing an erase saturation phenomenon. The non-volatile memory device has improved operating speed, memory window, and data capacity. When the gate electrode made of graphene is formed, the device lifetime under the voltage stress is greatly improved compared to when a conventional gate electrode made of TaN is used. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for MOSFET comprising gate oxide, gate electrode (24) made of graphene, and metal electrode (25) for capping. DESCRIPTION OF DRAWING(S) - The drawing is a sectional view of a non-volatile memory device. Tunnel oxide (21) Blocking oxide (23) Gate electrode (24) Metal electrode (25) Non-volatile memory device (100)