| 摘要 |
Method and apparatus for storing digital information in a dense memory structure. A semiconductor substrate has a thin insulating layer formed thereon. Over the thin insulating layer is formed a dielectric charge-storage layer. A piezoelectric bimorph cantilever arm has a tip formed at its free end to access certain memory sites defined by charge-storage regions in the charge-storage layer. To write infromation in the form of charges into a memory site the tip contacts or is in close proximity to the surface of the charge-storage layer and an electric field is applied between the tip and the substrate to induce charges to tunnel through the thin insulating layer into the charge-storage layer where the charges are stored as trapped charges. Information is read from a storage-site by spacing the tip of the cantilever arm a distance from the surface of the charge storage layer and applying an electric field between the tip and the substrate. The capacitive force on the tip is then measured to determine the amount of charge stored in that memory site. Alternatively charge is deposited directly on the surface of a single insulating layer. Charge sites are arranged in circular tracks on a rotating substratge to provide a high density memory array. Charge sites are also arranged in linear tracks by forming alternating layers of conductive and non-conductive substrate layers over which are formed thin insulating layers and charge-storage layers. This produces a number of spaced-apart charge-storage tracks. Tracks are also provided by depositing metal strips or scribing grooves on the surface of a device. |
