Described herein are techniques that improve the collection and readout of charge carriers in an integrated circuit. Some aspects of the present disclosure relate to integrated circuits having pixels with a plurality of charge storage regions. Some aspects of the present disclosure relate to integrated circuits configured to substantially simultaneously collect and read out charge carriers, at least in part. Some aspects of the present disclosure relate to integrated circuits having a plurality of pixels configured to transfer charge carriers between charge storage regions within each pixel substantially at the same time. Some aspects of the present disclosure relate to integrated circuits having three or more sequentially coupled charge storage regions. Some aspects of the present disclosure relate to integrated circuits capable of increased charge transfer rates. Some aspects of the present disclosure relate to techniques for manufacturing and operating integrated circuits according to the other techniques described herein.

An image reading apparatus includes an image reading chip for reading an image. The image reading chip includes a plurality of pixel units which include a light receiving element which receives light from the image so as to perform photoelectric conversion, an analog circuit, a logic circuit, and a power source pad to which a power source voltage is supplied. The image reading chip has a shape which includes a first side and a second side shorter than the first side. A distance between the analog circuit and a median point of the first side is shorter than a distance between the logic circuit and the median point of the first side, and a distance between the analog circuit and the power source pad is shorter than a distance between the logic circuit and the power source pad.

A high sensitivity image sensor comprises an epitaxial layer of silicon that is intrinsic or lightly p doped (such as a doping level less than about 10.sup.13 cm.sup.3). CMOS or CCD circuits are fabricated on the front-side of the epitaxial layer. Epitaxial p and n type layers are grown on the backside of the epitaxial layer. A pure boron layer is deposited on the n-type epitaxial layer. Some boron is driven a few nm into the n-type epitaxial layer from the backside during the boron deposition process. An anti-reflection coating may be applied to the pure boron layer. During operation of the sensor a negative bias voltage of several tens to a few hundred volts is applied to the boron layer to accelerate photo-electrons away from the backside surface and create additional electrons by an avalanche effect. Grounded p-wells protect active circuits as needed from the reversed biased epitaxial layer.

Various embodiments of the present disclosure are directed towards a semiconductor structure including a first substrate comprising a first semiconductor material. A first light sensor is disposed within the first substrate. The first light sensor is configured to absorb electromagnetic radiation within a first wavelength range. A second light sensor is disposed within an absorption structure underlying the first substrate. The second light sensor is configured to absorb electromagnetic radiation within a second wavelength range different from the first wavelength range. The absorption structure underlies the first light sensor and comprises a second semiconductor material different from the first semiconductor material.

Various embodiments of the present disclosure are directed towards an integrated chip comprising a first photodetector arranged in a first substrate. The first photodetector absorbs light in a first wavelength range. A second substrate underlies the first substrate. A second photodetector is arranged on the second substrate. The second photodetector absorbs light in a second wavelength range different from the first wavelength range. A dielectric structure is arranged between a first surface of the first substrate and a first surface of the second substrate.