Abstract: A flash memory capable of writing or deleting a split block is provided. A flash memory includes a memory array comprising a plurality of blocks, and a word line selection circuit, wherein each of the plurality of blocks is formed by a plurality of cell units in a well. The cell unit comprises N memory cells, a selection transistor coupled to one terminal of the memory cells, a selection transistor coupled to the other terminal of the memory cells, and a dummy selection transistor coupled between the memory cells. The word line selection circuit splits the block into a first block and a second block to use according to the operation of data writing or data deleting.

Abstract: A method for fabricating a semiconductor device is described. A plurality of isolation structures is formed in a substrate. The isolation structures are arranged in parallel and extend along a first direction. A well of a first conductive type is formed in the substrate. A plurality of first doped regions of a second conductive type is formed in the well. Each of the first doped regions is formed between two adjacent isolation structures. A plurality of gates of the second conductive type is formed on the substrate. The gates are arranged in parallel and extend along a second direction different from the first direction. One of the first doped regions is connected to one of the gates. A plurality of second doped regions of the first conductive type is formed in the well. Each of the second doped regions is formed in the first doped regions between two adjacent gates.