Abstract: The present application provides a memory device having a memory cell with reduced protrusion protruding from the memory cell. The memory device includes a semiconductor substrate having a fin portion protruding from a surface of the semiconductor substrate; a semiconductive layer disposed conformal to the fin portion; a conductive layer disposed over the semiconductive layer; an insulating layer disposed over the conductive layer; and a protrusion including a first protruding portion laterally protruding from the semiconductive layer and along the surface, a second protruding portion laterally protruding from the conductive layer and over the first protruding portion, and a third protruding portion laterally protruding from the insulating layer and over the second protruding portion, wherein the protrusion has an undercut profile.

Abstract: The present disclosure provides a semiconductor structure having an air gap surrounding a lower portion of a bit line, and a manufacturing method of the semiconductor structure. The semiconductor structure includes a substrate; a bit line structure disposed over the substrate; a first dielectric layer, surrounding the bit line structure; a second dielectric layer, surrounding a lower portion of the first dielectric layer, wherein the second dielectric layer is separated from the first dielectric layer by a first air gap; and a third dielectric layer, surrounding an upper portion of the first dielectric layer and sealing the first air gap.

Abstract: The present disclosure provides a method for manufacturing a semiconductor structure. The method includes: forming a bit line over a substrate; forming a first spacer layer over and conformal to the bit line; forming a sacrificial layer over and conformal to the first spacer layer; forming a second spacer layer over and conformal to the sacrificial layer; forming a mask layer covering a lower portion of the second spacer layer; removing an upper portion of the second spacer layer; removing the sacrificial layer; and forming a third spacer layer over the first spacer layer and the second spacer layer. thereby forming a first air gap surrounded by the lower portion of the second spacer layer.

Abstract: The present application provides a method of manufacturing a memory device.