Semiconductor device and manufacturing method thereof

A semiconductor device comprising:

• a plurality of pixels arranged in a matrix, each of the plurality of pixels comprising:
• a photodiode;
• a charge accumulation control transistor, wherein one of a source and a drain of the charge accumulation control transistor is electrically connected to the photodiode;
• a reset transistor, wherein one of a source and a drain of the reset transistor is electrically connected to the other of the source and the drain of the charge accumulation control transistor;
• and
• an amplifying transistor, wherein a gate of the amplifying transistor is electrically connected to the other of the source and the drain of the charge accumulation control transistor and the one of the source and the drain of the reset transistor,
• wherein a channel formation region in at least one of the charge accumulation control transistor and the reset transistor comprises an oxide semiconductor,
• wherein gates of the reset transistors in the plurality of pixels arranged in the matrix are electrically connected to each other, and
• wherein gates of the charge accumulation control transistors in the plurality of pixels are electrically connected to each other.

A semiconductor device comprising:

• a plurality of pixels arranged in a matrix, each of the plurality of pixels comprising:
• a photodiode;
• a signal charge accumulation portion electrically connected to the photodiode;
• a transistor, wherein a gate of the transistor is electrically connected to the signal charge accumulation portion, and
• a capacitor, wherein one of electrodes of the capacitor is electrically connected to the signal charge accumulation portion,
• wherein a channel formation region in the transistor comprises an oxide semiconductor, and
• wherein after a reset operation of the signal charge accumulation portion is performed in the plurality of pixels arranged in the matrix at substantially the same time, a charge accumulation operation by the photodiode is performed in the plurality of pixels at substantially the same time, and a read operation of a signal from each of the plurality of pixels is performed per row.

A driving method of a semiconductor device comprising a plurality of pixels arranged in a matrix, each of the plurality of pixels comprising a photodiode, a signal charge accumulation portion, a charge accumulation control transistor, a reset transistor, an amplifying transistor, and a selection transistor, wherein one of a source and a drain of the charge accumulation control transistor is electrically connected to the photodiode, the other of the source and the drain of the charge accumulation control transistor is electrically connected to the signal charge accumulation portion, one of a source and a drain of the reset transistor is electrically connected to the signal charge accumulation portion, a gate of the amplifying transistor is electrically connected to the signal charge accumulation portion, and one of a source and a drain of the selection transistor is electrically connected to one of a source and a drain of the amplifying transistor, comprising the steps of:

• turning on the charge accumulation control transistors in the plurality of pixels simultaneously;
• turning on the reset transistors in the plurality of pixels simultaneously, and setting a potential of the signal charge accumulation portion in each of the plurality of pixels to a reset potential;
• turning off the reset transistors in the plurality of pixels simultaneously, and changing the potential of the signal charge accumulation portion in each of the plurality of pixels;
• turning off the charge accumulation control transistors in the plurality of pixels simultaneously, and holding the potential of the signal charge accumulation portion in each of the plurality of pixels;
• and
• turning on the selection transistors per row sequentially, and outputting a signal corresponding to the potential of the signal charge accumulation portion in each of the plurality of pixels from the amplifying transistor in each of the plurality of pixels,
• wherein a channel formation region of at least one of the charge accumulation control transistor and the reset transistor comprises an oxide semiconductor.

A driving method of a semiconductor device comprising a plurality of pixels arranged in a matrix, each of the plurality of pixels comprising a photodiode, a signal charge accumulation portion, a charge accumulation control transistor, a reset transistor, an amplifying transistor, and a selection transistor, wherein one of a source and a drain of the charge accumulation control transistor is electrically connected to the photodiode, the other of the source and the drain of the charge accumulation control transistor is electrically connected to the signal charge accumulation portion, one of a source and a drain of the reset transistor is electrically connected to the signal charge accumulation portion, a gate of the amplifying transistor is electrically connected to the signal charge accumulation portion, and one of a source and a drain of the selection transistor is electrically connected to one of a source and a drain of the amplifying transistor, comprising the steps of:

• turning on the charge accumulation control transistor in each of the plurality of the pixels simultaneously;
• turning on the reset transistor in each of the plurality of the pixels simultaneously, and setting a potential of the signal charge accumulation portion in each of the plurality of the pixels to a reset potential;
• turning off the charge accumulation control transistor in each of the plurality of the pixels simultaneously, and changing a potential of a cathode of the photodiode in each of the plurality of the pixels;
• turning off the reset transistor in each of the plurality of the pixels simultaneously, and holding the potential of the signal charge accumulation portion in each of the plurality of the pixels;
• turning on the charge accumulation control transistor in each of the plurality of the pixels simultaneously, and changing the potential of the signal charge accumulation portion in each of the plurality of the pixels;
• turning off the charge accumulation control transistor in each of the plurality of the pixels simultaneously, and holding the potential of the signal charge accumulation portion;
• and
• turning on the selection transistors per row sequentially, and outputting a signal corresponding to the potential of the signal charge accumulation portion in each of the plurality of the pixels from the amplifying transistor in each of the plurality of the pixels,
• wherein a channel formation region in at least one of the charge accumulation control transistor and the reset transistor comprises an oxide semiconductor.