Manufacturing method of three-dimensional memory

The invention relates to a manufacturing method of a three-dimensional memory, and the method comprises the following steps: forming a stack structure on a substrate, wherein the stack structure comprises a plurality of gate sacrificial layers and insulating layers which are alternately stacked in a direction perpendicular to the substrate; forming a channel hole at least penetrating through the stack structure so as to expose part of the substrate; injecting hydrogen ions into the upper surface of the substrate below the channel hole through the channel hole so as to remove impurity element pollution on the upper surface of the substrate; and forming an epitaxial layer at the bottom of the channel hole, so the influence of impurity element pollution on the upper surface of the substrate on the growth quality of the epitaxial layer can be avoided by removing the impurity element pollution on the upper surface of the substrate in advance, and the yield and reliability of the three-dimensional memory are furthe