Abstract: A method for preparing a flash memory structure comprises the steps of forming a plurality of dielectric blocks having block sidewalls on a substrate, forming a plurality of first spacers on the block sidewalls of the dielectric blocks, removing a portion of the substrate not covered by the dielectric blocks and the first spacers to form a plurality of trenches in the substrate, performing a deposition process to form an isolation dielectric layer filling the trenches, removing the dielectric blocks to expose spacer sidewalls of the first spacers, forming a plurality of second spacers on the spacer sidewalls of the first spacers, and removing a portion of the substrate not covered by the first spacers, the second spacers and the isolation dielectric layer to form a plurality of second trenches in the substrate.

Abstract: A method for fabricating a non-volatile memory is provided. Parallel-arranged isolation structures are disposed in a substrate and protrude from the surface of the substrate to define active regions. Mask layers intersecting the isolation structures are deposited on the substrate. The surface of the mask layers is higher than that of the isolation structures. Doped regions are formed in the substrate. Insulating layers are deposited on the substrate between the mask layers. The insulating layers and the mask layers have different etch selectivities. The mask layers are removed to expose the substrate. A tunneling dielectric layer is formed on the substrate. A floating gate is deposited on the substrate surrounded by the isolation structures and the insulating layers. The surface of the floating gate is lower than that of the isolation structures. An inter-gate dielectric layer is deposited on the substrate. A control gate is disposed between the insulating layers.

Abstract: A novel NAND flash memory cell array and the method of fabricating the same are disclosed in this invention. The NAND flash memory cell array comprises a substrate with an active area; a plurality of cells arranged in a row on the active area; a first barrier layer covering the cells and the active area around each end of the row; a first oxide deposited to fill a gap between the cells; an oxide spacer formed along the sidewall of a cell located at each end of the row; and a poly spacer formed on the oxide spacer acting as a selection gate for driving the row of cells. The aspect ratio of the gap between the cells is about 1.8 to 3.2. Many advantages are provided with such NAND flash memory fabricating by the self-aligned process of the present invention.