Semiconductor device, manufacturing method thereof, and electronic device

The invention provides a semiconductor device, a manufacturing method thereof, and an electronic device. The manufacturing method comprises: providing a semiconductor substrate on which an isolation structure and an active region divided by the isolation structure are formed; forming a floating gate on the active region, and control gates on the floating gate; forming an interlayer dielectric layer over the active region and the isolation structure, the interlayer dielectric layer being formed in a gap between the control gates and covering the control gates, wherein the isolation structure comprises a first region on the semiconductor substrate and a second region on the first region, and the second region of the isolation structure includes an insulating layer on the outer side and a bitline air gap located inside and surrounded by the insulating layer. The manufacturing method can reduce bit line interference and crosstalk problems, improve performance of a flash memory, and cycletime/reading times. The se