Manufacturing method of memory cell

The embodiment of the invention provides a manufacturing method of a storage unit. The manufacturing method comprises the following steps: providing a substrate; forming a source/drain feature of the transistor in the substrate; forming a first dielectric layer over the substrate; forming a gate of a transistor in the first dielectric layer; forming a second dielectric layer over the first dielectric layer; forming a first contact feature in the second dielectric layer; forming a first barrier layer that completely surrounds and directly contacts the top surface, the bottom surface, and the side surfaces of the first contact member; forming a resistive material layer disposed over the first contact feature; forming a second contact feature disposed over the resistive material layer; forming a second barrier layer that completely surrounds and directly contacts the top surface, the bottom surface, and the side surfaces of the second contact member; a conductive plug is formed within the first dielectric layer,