US Patent 9209212 Image sensor including source follower

Provided is an image sensor including a source follower transistor. The source follower transistor may include a channel structure that is provided between a source and a drain, and includes a first semiconductor layer, a second semiconductor layer, and a blocking structure. The first semiconductor layer may be spaced apart from a gate insulating layer of the source follower transistor by a first depth or more. Carriers may move from the source of the source follower transistor to the drain thereof through the first semiconductor layer.