Solid-state image pickup device and image pickup system

A solid-state image pickup device comprising:

• a first substrate including a photoelectric conversion element and a transfer gate electrode configured to transfer charge from the photoelectric conversion element;
• a second substrate having a peripheral circuit portion including a circuit configured to read a signal based on charge generated in the photoelectric conversion element, the first and second substrates being laminated;
• a multilayer interconnect structure, disposed on the first substrate, including a first interconnect layer and a second interconnect layer, the first interconnect layer being arranged between the second interconnect layer and the first substrate, the first interconnect layer including an aluminum interconnect;
• and
• a multilayer interconnect structure, disposed on the second substrate, including a third interconnect layer and a fourth interconnect layer, the third interconnect layer being arranged between the fourth interconnect layer and the second substrate, the third interconnect layer including a copper interconnect.