Nec Corporation

Michihiro Morimoto

Takashi Sato

Masayuki Furumiya

Keisuke Hatano

Nobukazu Teranishi

Shinichi Kawai

Takao Tamura

Ichiro Murakami

Chihiro Ogawa

Yasuaki Hokari

Nobuhiko Mutoh

Kouichi Arai

Kozo Orihara

Shinobu Suwazono

Hiroaki Utsumi

A charge transfer device is provided, capable of preventing degradation of the charge transfer efficiency when the channel width becomes narrower due to the narrow channel effect. The charge transfer device of the present invention is obtained by forming a charge transfer electric field in a channel below a boundary portion between a terminal storage electrode and a terminal barrier electrode, which constitute a pair of charge transfer electrodes located closest to the output electrode, to be higher than a charge transfer electric field in a channel below a boundary portions of pairs of storage electrodes and barrier electrodes, which constitute pairs of storage electrodes and barrier electrodes other than the pair of the terminal electrodes.

Charge transfer device and solid image pickup apparatus using the same

Shunt wirings (12) in the form of a conductive light intercepting film which covers over vertical CCD registers and also serves to supply power, project into locations between adjacent photoelectric transducers (11) in the vertical direction, and the distance between the projecting portions of adjacent ones of the metal wirings is set to 0.2 .mu.m or less and is limited to a distance with which an electric field between adjacent ones of the metal wirings is 10.sup.7 V/cm or less and the adjacent metal wirings do not suffer from short-circuiting.

Solid state imaging apparatus having a plurality of metal wirings for

By segmenting an image sensing area into a plurality of partial areas and changing the number of stages of dummy vertical electrodes to be inserted between vertical CCD registers and horizontal CCD registers, the output gate electrode, floating diffusion layer, reset gate electrode and rest drain of each horizontal CCD register can be aligned in a line to the main body of the horizontal CCD register. It is therefore possible to avoid the reduction of the transfer efficiency at the time of transferring charges, which have reached the channel under the horizontal transfer electrode, to the channel under a dummy horizontal transfer electrode.

Solid state image sensing device

In a solid-state image pickup device having photoelectric converting sections, vertical charge transfer sections, and a horizontal charge transfer section, the vertical charge transfer sections include first, second, and third vertical charge transfer electrodes The third (final) vertical charge transfer electrode, which is adjacent to the horizontal charge transfer section, is electrically connected to a shunt wire (a first shading film) via lining contacts. A second shading film is formed electrically separated from the shunt wire, for light-shielding areas between photoelectric converting sections in a vertical direction.

Solid-state image pickup device capable of reducing fixed pattern noise

In the solid-state image pickup device of the present invention, a two-layer structure of the second diffusion layer of the first conductive type and the third diffusion layer of the first conductive type that has a higher density is uniformly formed as an isolation area along a transfer channel between each photodiode string and each vertical CCD register. Therefore, a constant effective width for the transfer channel is provided and a preferable transfer efficiency is achieved. Further, the occurrence of a punch-through between the photodiode and the vertical CCD register can be prevented, isolation between the photodiode and the vertical CCD register can be ensured, and the reading of electric charges from the photodiode to the vertical CCD register can be performed at a lower voltage.

Solid-state image pickup device

A charge transfer device comprises an array of photodiodes, vertical registers having channels for receiving charge packets from the photodiodes and vertical electrodes for shifting the charge packets along the channels of the vertical registers. A horizontal register has channels for receiving the charge packets from the vertical registers and horizontal electrodes for successively shifting the charge packets across the channels of the horizontal register. An overflow barrier region extends across and is embedded below the channels of the horizontal register for establishing a barrier potential. An overflow drain region is connected to the channels of the horizontal register for discharging charge packets which exceed the barrier potential.

CCD image sensor with overflow barrier for discharging excess electrons

In a solid state image pick-up device having a vertical overflow drain structure, a voltage to be applied to a semiconductor substrate is lowered in stepwise manner during a period, in which a charge photoelectrically converted by a photodiode is accumulated in the photodiode. Expansion of a dynamic range relative to an incident light intensity can be realized without performing high speed transfer in a vertical CCD register. Then, lowering power consumption and lowering of noise of the solid state image pick-up device becomes possible.

Driving method for driving a solid state image pick-up device

The solid-state image sensor disclosed has a photodiode including a P-type layer provided on a surface of a semi-conductor substrate, an N-type layer provided in the N-type layer, and a P.sup.+ -type region which is disposed on a surface of the N-type layer. A P.sup.++ -type region is disposed in a region surrounding the photodiode excepting in a read region for reading out charges in the photodiode, and this P.sup.++ -type region has a higher impurity concentration and a greater depth than the P.sup.+ -type region. That is, the P.sup.++ -type region which isolates photodiode regions and vertical CCD regions from one another is formed as a high impurity concentration diffusion layer or an electron trap region containing a large amount of electron trap centers. Thus, it is possible to reduce smear generation in unit pixels and to produce sharp images.

Solid-state image sensor with element isolation region of high impurity

In a solid-state image sensing device in which metallic wirings for supplying drive pulses to every transfer electrodes of vertical CCD registers are provided on the vertical CCD registers, the spacings between the metallic wirings are given mutually different sizes for an effective image sensing region and an optical black region. The shape of the step part beneath a light shielding film in the optical black region is improved, and the transmission of light is prevented. Accordingly, a correct black reference level can be obtained.

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Tokyo, Japan

Michihiro Morimoto