Semiconductor device and manufacturing method thereof

摘要

In a CMOS image sensor in which a plurality of pixels is arranged in a matrix, a transistor in which a channel formation region includes an oxide semiconductor is used for each of a charge accumulation control transistor and a reset transistor which are in a pixel portion. After a reset operation of the signal charge accumulation portion is performed in all the pixels arranged in the matrix, a charge accumulation operation by the photodiode is performed in all the pixels, and a read operation of a signal from the pixel is performed per row. Accordingly, an image can be taken without a distortion.

主权项

1. A semiconductor device comprising:
a first pixel; and a second pixel, wherein the first pixel comprises:
a first photoelectric conversion element;a first transistor; anda second transistor, wherein the second pixel comprises:
a second photoelectric conversion element;a third transistor; anda fourth transistor, wherein the first transistor is configured to output a signal corresponding to a potential of a first signal charge accumulation portion, wherein the second transistor is configured to control charge accumulation in the first signal charge accumulation portion performed by the first photoelectric conversion element, wherein the third transistor is configured to output a signal corresponding to a potential of a second signal charge accumulation portion, wherein the fourth transistor is configured to control charge accumulation in the second signal charge accumulation portion performed by the second photoelectric conversion element, wherein a channel formation region in the second transistor comprises an oxide semiconductor, wherein a channel formation region in the fourth transistor comprises an oxide semiconductor, wherein a gate of the second transistor is electrically connected to a gate of the fourth transistor, wherein a reset operation in the first pixel and a reset operation in the second pixel are performed at substantially the same time, and wherein a timing of a read operation in the first pixel and a timing of a read operation in the second pixel are different from each other.