Formation method of semiconductor structure

A forming method of a semiconductor structure comprises the steps that a substrate is provided, and the substrate comprises a device region and an isolation region which are arranged in the first direction; forming a gate structure extending along a second direction on the substrate, wherein the second direction is vertical to the first direction; forming a mask structure on the gate structure; performing first patterning processing on the mask structure to form a first opening which exposes a part of the surface of the gate structure; part of the gate structure is removed along the first opening, a first groove is formed in the gate structure, and the first groove penetrates through the gate structure in the first direction; forming a first isolation structure in the first groove; patterning the mask structure for the second time to form a second opening which exposes the surface of the gate structure of the isolation region; removing the gate structure of the isolation region along the second opening to for