Semiconductor device to include a first transistor with a silicon channel formation region and a second transistor with an oxide semiconductor channel formation region

摘要

A semiconductor device including photosensor capable of imaging with high resolution is disclosed. The semiconductor device includes the photosensor having a photodiode, a first transistor, and a second transistor. The photodiode generates an electric signal in accordance with the intensity of light. The first transistor stores charge in a gate thereof and converts the stored charge into an output signal. The second transistor transfers the electric signal generated by the photodiode to the gate of the first transistor and holds the charge stored in the gate of the first transistor. The first transistor has a back gate and the threshold voltage thereof is changed by changing the potential of the back gate.

主权项

1. A semiconductor device comprising a plurality of photosensors, at least one of the plurality of photosensors comprising:
a photodiode; and first and second transistors each comprising a gate, a first terminal, and a second terminal, wherein the first terminal of the second transistor is directly connected to the photodiode, wherein the second terminal of the second transistor is directly connected to the gate of the first transistor, wherein the first transistor comprises a channel formation region comprising silicon, and wherein the second transistor comprises a channel formation region comprising an oxide semiconductor.