A manufacturing method of a semiconductor structure includes the following steps. A patterned photoresist layer is formed on a wafer of the wafer structure. The wafer is etched, such that channels are formed in the wafer, and a protection layer of the wafer structure is exposed through the channels. The protection layer is etched, such that openings aligned with the channels are formed in the protection layer. Landing pads in the protection layer are respectively exposed through the openings and the channels, and the caliber of each of the openings is gradually increased toward the corresponding channel. Side surfaces of the wafer surrounding the channels are etched, such that the channels are expanded to respectively form hollow regions. The caliber of the hollow region is gradually decreased toward the opening, and the caliber of the opening is smaller than that of the hollow region.