Semiconductor device, method for manufacturing the same, three-dimensional memory, and storage system

Abstract

The application provides a semiconductor device, a manufacturing method thereof, a three-dimensional memory and a storage system. The manufacturing method of the semiconductor device comprises: forming a semiconductor structure, the semiconductor structure comprising a substrate, a stack structure on the substrate, a channel structure penetrating through the stack structure, and a dielectric layer covering the stack structure and at least part of the substrate; forming a ring-shaped trench, the ring-shaped trench penetrating through the dielectric layer and extending to the substrate, and surrounding the stack structure; forming a trench flaring portion downward at the top of the ring-shaped trench; forming an opening in the dielectric layer covering the channel structure; wherein the trench flaring portion and the opening are formed in the same etching step. By the method of the application, the trench flaring portion is formed downward at the top of the ring-shaped trench, i.e. the ring-shaped trench is flared, which is beneficial to the filling quality of the filling material of the trench, improves the problem that fluorine-containing gas diffuses out of the gap of the filling material, and improves the yield and reliability of the device.

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