Solid-state imaging apparatus and driving method thereof
AssigneeSony Corporation
InventorsRyoji Suzuki, Takahisa Ueno, Keiji Mabuchi
Life of this patent
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Abstract
Each unit pixel includes a photodiode, a reading selection transistor, a reading transistor, an amplifying transistor, a reset transistor, and a horizontal selection transistor, and thus a MOS image sensor of a dot-sequential reading 5-Tr type is formed. The reading selection transistor and the reading transistor are formed with a two-layer gate structure, and gate potential of the reading selection transistor and the reading transistor is set to a negative potential. Thereby, a lower layer of a gate region of the reading transistor and the reading selection transistor is controlled to a negative potential. Thus, depletion in the lower layer region is suppressed to reduce leakage current.
Claims19
A solid-state imaging apparatus comprising:
- a plurality of pixels arranged in a two-dimensional matrix form;
- and, said pixels, being comprised of:
- a photoelectric converting element providing a signal according to an amount of light received;
- a floating diffusion portion receiving the signal charge accumulated by said photoelectric converting element;
- an amplifying transistor for amplifying a signal level of said floating diffusion portion;
- a reading transistor for transferring the signal accumulated by said photoelectric converting element to the floating diffusion portion;
- and
- a reading selection transistor for controlling said reading transistor;
- wherein a gate potential of at least one of said reading transistor and said reading selection transistor proximate said photoelectric converting element is set to a negative potential with respect to a well region.
A driving method of a solid-state imaging apparatus, said solid-state imaging apparatus comprising:
- exposing light upon a plurality of pixels arranged in a two-dimensional matrix form;
- and,
- photoelectric converting the light and
- accumulating a signal according to an amount of light received at each pixel;
- transferring the accumulated signal to a floating diffusion portion;
- amplifying a signal level of said floating diffusion portion;
- controlling said reading transistor via a reading selection transistor;
- wherein gate electrodes of said reading transistor and said reading selection transistor are formed by using two electrode layers different from each other, a gate potential of at least the transistor proximate the photoelectric converting element is set to a negative potential, and the gate electrode of said transistor proximate a photoelectric converting element is controlled to a negative potential during at least a part of a non-selection period.
Dependencies are inferred from the claim text.