Solid-state image pickup device having a level shift unit and signal processing unit where a voltage range supplied to the level shift unit is wider than a voltage range supplied to the signal processing unit
Dark current from a transfer transistor is suppressed and power-supply voltage in a second semiconductor substrate is lowered. A solid-state image pickup device includes a pixel array, a plurality of common output lines receiving signals read out from a plurality of pixels, a transfer scanning unit sequentially driving the plurality of transfer transistors, a signal processing unit processing the signals output to the common signal lines, and a level shift unit making amplitude of a pulse supplied to a gate of the transfer transistor larger than amplitude of a pulse supplied to a gate of a transistor constituting the signal processing unit. The pixel array and the level shift unit are arranged on a first semiconductor substrate, whereas the plurality of common output lines and the signal processing unit are arranged on a second semiconductor substrate.
1. A solid-state image pickup device comprising:
a pixel array including a plurality of pixels, each of the plurality of pixels including a photoelectric conversion unit and a transfer transistor configured to transfer charge generated in the photoelectric conversion unit;
a plurality of common output lines configured to receive signals generated in the plurality of pixels included in the pixel array;
a transfer scanning unit configured to sequentially drive the plurality of transfer transistors;
a signal processing unit configured to process the signals generated in the plurality of pixels; and
a level shift unit, arranged at an electrical path between the transfer scanning unit and the transfer transistor, configured to receive a pulse from the transfer scanning unit and increase an amplitude of the pulse and supply a gate of the transfer transistor with the pulse having the increased amplitude,
wherein the pixel array and the level shift unit are arranged on a first semiconductor substrate, whereas the plurality of common output lines, the signal processing unit, and the transfer scanning unit are arranged on a second semiconductor substrate, and
wherein a voltage range supplied to the level shift unit is wider than a voltage range supplied to the signal processing unit,
wherein a gate insulating film of a transistor arranged on the level shift unit is thicker than a gate insulating film of a transistor arranged on the signal processing unit.
2. The solid-state image pickup device according to claim 1 , wherein the pixel further includes an amplifying unit configured to amplify a signal based on the charge generated in the photoelectric conversion unit.
3. The solid-state image pickup device according to claim 1 , further comprising:
a transfer buffer unit in a path between the transfer transistors and the transfer scanning unit, the transfer buffer unit buffering a signal from the transfer scanning unit and including the level shift unit.
4. The solid-state image pickup device according to claim 1 , each of the plurality of pixels further including a reset unit, the solid-state image pickup device further comprising:
a reset scanning unit configured to sequentially drive the plurality of reset units; and
a reset buffer unit in a path between the reset units and the reset scanning unit, the reset buffer unit buffering a signal from the reset scanning unit.
5. The solid-state image pickup device according to claim 3 , each of the plurality of pixels further including a reset unit, the solid-state image pickup device further comprising:
a reset scanning unit configured to sequentially drive the plurality of reset units, and wherein
the transfer scanning unit and the reset scanning unit are integrated.
6. The solid-state image pickup device according to claim 2 , wherein
each of the plurality of pixels includes a reset transistor, and wherein
the transfer transistor is a MOS transistor having a first conductivity type, the reset transistor is a MOS transistor having a second conductivity type, and the amplifying unit includes a source follower constituted by a transistor having the second conductivity type.