Semiconductor device including an oxide semiconductor layer

摘要

A solid-state image sensor which holds a potential for a long time and includes a thin film transistor with stable electrical characteristics is provided. When the off-state current of a thin film transistor including an oxide semiconductor layer is set to 1×10−13 A or less and the thin film transistor is used as a reset transistor and a transfer transistor of the solid-state image sensor, the potential of the signal charge storage portion is kept constant, so that a dynamic range can be improved. When a silicon semiconductor which can be used for a complementary metal oxide semiconductor is used for a peripheral circuit, a high-speed semiconductor device with low power consumption can be manufactured.

主权项

1. A semiconductor device comprising:
a photoelectric conversion element; a first transistor; a second transistor; a third transistor; and an interlayer insulating film, wherein a gate electrode of the first transistor is electrically connected to one of a source electrode and a drain electrode of the second transistor, wherein the gate electrode of the first transistor is electrically connected to one of a source electrode and a drain electrode of the third transistor, wherein one of a source electrode and a drain electrode of the first transistor is electrically connected to a first line, wherein a gate electrode of the second transistor is electrically connected to a second line, wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to the photoelectric conversion element, wherein a gate electrode of the third transistor is electrically connected to a third line, wherein the photoelectric conversion element is electrically connected to the gate electrode of the first transistor through the second transistor so that the gate electrode of the first transistor is capable of storing electrical charge, wherein a channel of the second transistor comprises a first oxide semiconductor layer, wherein a channel of the third transistor comprises a second oxide semiconductor layer, wherein the interlayer insulating film is over the photoelectric conversion element, and wherein the third transistor is over the interlayer insulating film.