VERTICAL CHANNEL-TYPE THREE-DIMENSIONAL SEMICONDUCTOR MEMORY DEVICE AND PREPARATION METHOD THEREFOR

摘要

A vertical channel-type three-dimensional semiconductor memory device and a preparation method therefor. The three-dimensional semiconductor memory device includes: a substrate; a multilayer film structure formed by sequentially and alternately depositing insulating layers and electrode material layers on the substrate; a plurality of through-holes formed by etching the multilayer film structure to the substrate; a plurality of gate stacks formed by sequentially depositing barrier layers, accumulation layers and tunnelling layers on the inner walls of the plurality of through-holes; a plurality of hollow channels formed by depositing a channel material on the surfaces of the tunnelling layers of the plurality of gate stacks; a drain electrode formed in a contact region of a contact hole for bit line connection above the hollow channels; and a source electrode formed in a contact region of the through-holes and the substrate below the hollow channels. The semiconductor memory device and preparation method therefor overcome the technical problem of small ON-state channel current brought by low carrier mobility of a conventional polysilicon channel, improve the consistency and reliability of the memory property of each memory cell in the vertical direction and reduce the difficulty and cost for fabricating a vertical channel.