Manufacturing method of memory device

Abstract

A manufacturing method of a memory device, including forming a hard mask layer over a substrate, in which the hard mask layer is made of an oxide-based material, and the hard mask layer has a first width, forming a trench in the substrate through the hard mask layer, performing a first cleaning process to the substrate, in which the first width of the hard mask layer is reduced to a second width after the first cleaning process is complete, forming a first dielectric layer lining the trench, forming a first word line layer in the trench, forming a second word line layer in the trench and over the first word line layer, forming a cap layer in the trench and over the second word line layer, removing the hard mask layer, and forming a gate contact layer over the cap layer.

Dependencies are inferred from the claim text.