Nonvolatile memory structure and manufacturing method thereof

The invention provides a nonvolatile memory structure and a manufacturing method thereof. The nonvolatile memory structure comprises a substrate and a tunneling dielectric layer on the substrate. A plurality of gate structures disposed in the array region of the substrate and spaced apart from each other, each gate structure including a floating gate and a control gate disposed above the floating gate. The first dielectric layer is located above the tunneling dielectric layer and covers the gate structures, the first dielectric layer is formed above the substrate and covers the top surface of the tunneling dielectric layer and covers the side surfaces and the top surfaces of the gate structures, and the space between the first dielectric layers on the side surfaces of the adjacent gate structures is filled with an air gap. The insulating blocks are located on the first dielectric layer and correspond to the gate structures respectively, the second dielectric layer is located on the insulating blocks and cover