Oxide semiconductor device including photodiode

摘要

A solid-state image sensing element including a transistor with stable electrical characteristics (e.g., significantly low off-state current) is provided. Two different element layers (an element layer including an oxide semiconductor layer and an element layer including a photodiode) are stacked over a semiconductor substrate provided with a driver circuit such as an amplifier circuit, so that the area occupied by a photodiode is secured. A transistor including an oxide semiconductor layer in a channel formation region is used as a transistor electrically connected to the photodiode, which leads to lower power consumption of a semiconductor device.

主权项

1. A semiconductor device comprising:
a driver circuit comprising a first transistor comprising a first channel formation region, the first transistor being provided on a top surface of a semiconductor substrate; a second transistor comprising an oxide semiconductor layer including indium in a second channel formation region over the first transistor; and a photodiode over the second transistor, the photodiode being electrically connected to the second transistor, wherein a gate electrode layer of the second transistor overlaps a gate electrode layer of the first transistor when seen from a direction perpendicular to the top surface of the semiconductor substrate.