Flash memory and fabrication method and operation method for the same

Abstract

The present invention discloses a flash memory and the fabrication method and the operation method for the same. The flash memory comprises two memory cells of vertical channels, wherein a lightly-doped N type (or P type) silicon is used as a substrate; a P+ region (or an N+ region) is provided on each of the both ends of the silicon surface, and two channel regions perpendicular to the surface are provided therebetween; an N+ region (or a P+ region) shared by two channels is provided over the channels; a tunneling oxide layer, a polysilicon floating gate, a block oxide layer and a polysilicon control gate are provided sequentially on the outer sides of each channel from inside to outside; and the polysilicon floating gate and the polysilicon control gate are isolated from the P+ region by a sidewall oxide layer. The whole device is a two-bit TFET type flash memory with vertical channels which has better compatibility with prior-art standard CMOS process. As compared with a conventional MOSFET-based flash memory, the flash memory according to the present invention possesses various advantages such as high programming efficiency, low power consumption, effective inhibition of punch-through effect, and high density, etc.