HIGH-DENSITY FLASH MEMORY CELL STACK, CELL STACK STRING, AND FABRICATION METHOD THEREOF

摘要

The present invention relates to a flash memory cell stack, a flash memory cell stack string, a cell stack array, and a fabrication method thereof. The flash memory cell stack comprises: a semiconductor substrate; a control electrode formed into an upright column shape on the surface of the semiconductor substrate; an insulating film formed between the control electrode and the semiconductor substrate; a gate stack formed at the side surface of the control electrode; a plurality of first insulation films formed into a layer on the side surface of the gate stack; a plurality of second doping semiconductor areas formed into a layer on the side surface of the gate stack; and a first doping semiconductor area formed on parts of the side surfaces of the first insulation films and the side surfaces of the second doping semiconductor areas in such a manner that the first doping semiconductor area is formed on the opposite side surfaces of the first insulation films and the second doping semiconductor areas along a first direction. The first insulation films and the second doping semiconductor areas are formed into alternate layers on the side surface of the gate stack. The flash memory cell stack string is formed from a plurality of flash memory cell stacks arranged into a line. The cell stack array is formed from a plurality of flash memory cell stack strings arranged into a line.