Image sensor and manufacturing method thereof

Provided are embodiments of an image sensor. The image sensor can comprise a first substrate including a transistor circuit, a lower interconnection layer, an upper interconnection layer, and a second substrate including a vertical stacked photodiode. The lower interconnection layer is disposed on the first substrate and comprises a lower interconnection connected to the transistor circuit. The upper interconnection layer is disposed on the lower interconnection layer and comprises an upper interconnection connected with the lower interconnection. The vertical stacked photodiode can be disposed on the upper interconnection layer and connected with the upper interconnection through, for example, a single plug connecting a blue, green, and red photodiode of the vertical stack or a corresponding plug for each of the blue, green, and red photodiode of the vertical stack.