Manufacturing method of semiconductor structure and semiconductor structure

A manufacturing method of a semiconductor structure, comprising:

• providing a substrate, wherein the substrate comprises an active region;
• forming a first intermediate dielectric layer, wherein the first intermediate dielectric layer has an opening, and the opening exposes a part of a top surface of the substrate;
• forming a second dielectric layer in the opening, wherein the first intermediate dielectric layer is connected to the second dielectric layer, and a thickness of the second dielectric layer is less than a thickness of the first intermediate dielectric layer;
• forming a gate structure, wherein orthographic projection of the gate structure on the substrate covers orthographic projection of the second dielectric layer and orthographic projection of a part of the first intermediate dielectric layer on the substrate;
• removing a part of the first intermediate dielectric layer not covered by the gate structure, wherein the retained first intermediate dielectric layer forms a first dielectric layer;
• and
• forming a source region of a first doping type and a drain region of the first doping type in the active region, wherein the first dielectric layer is formed on at least one of a part of the source region or a part of the drain region, and the second dielectric layer is connected to a side of the first dielectric layer that is away from at least one of the source region or the drain region;
• the first dielectric layer is partially provided on the substrate, a top of the first dielectric layer is flush with a top of the second dielectric layer, and a bottom of the first dielectric layer is lower than a bottom of the second dielectric layer.