US Patent 7745250 Image sensor and method for manufacturing the same

An image sensor and manufacturing process thereof are provided. An image sensor according to an embodiment comprises a first wafer formed with a photodiode cell without a microlens and a second wafer formed with a circuit part including transistor and a capacitor. The first wafer is stacked on the second wafer such that a connecting electrode can be used to electrically connect the photodiode cell of the first wafer to the circuit part of the second wafer.