Memory, preparation method thereof and memory system

The invention discloses a memory, a preparation method thereof and a memory system, a stack layer is formed on a substrate, and the stack layer comprises a first area and a second area adjacent to the first area; a patterned hard mask layer is formed on the stacking layer, a first stop layer covering the first area is formed in the patterned hard mask layer, and the patterned hard mask layer comprises a first opening pattern located on the first stop layer and a channel hole pattern located on the stacking layer and corresponding to the second area; and finally, etching the stack layer based on the patterned hard mask layer so as to form a channel hole in the second region. The first stop layer can ensure that the stack layer of the first region is not etched. When the stack layer is etched, at the junction of the region where the channel hole needs to be formed and the region where the channel hole does not need to be formed, the influence of residual molecules gathered at the junction on the etching of the