JP2005166826A - Solid-state imaging apparatus and camera including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging apparatus which can save the number of pixels in the horizontal direction and output at a high speed the high quality image signal without generation of moire and false signal. <P>SOLUTION: The solid-state imaging apparatus comprises an imaging section 140 formed of a plurality of photoelectric converter 100 and a vertical transfer 110, a horizontal transfer 120, and a sharing transfer 130 allocated between the imaging part 140 and the horizontal transfer 120. The sharing transfer 130 is provided with a plurality of independent electrodes for independently controlling, for each column, the read operation of signal charges to the horizontal transfer 120 from the vertical transfer 110. The wiring connected to the independent electrodes is formed bridging over the horizontal transfer 120. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solid-state imaging device that converts received light into an electrical signal and outputs it as a video signal.

Conventionally, a solid-state imaging device that converts received light into an electrical signal and outputs it as a video signal is known, and a camera such as a digital still camera that displays a video signal obtained from the solid-state imaging device as a still image is known. ing. In recent years, a camera using such a solid-state imaging device has been demanded to further improve image quality and function, and the density of image quality has been increasing.
In such a solid-state imaging device, in order to improve the output speed of the video signal, a driving method that reduces the number of pixels in the output video signal by thinning out pixels from which signal charges are read has been proposed. For example, in Patent Document 1, signal charges of two pixels (two pixels at both ends) excluding the central pixel in each block are mixed in the solid-state imaging device, with three pixels in the horizontal direction as one block, and one pixel at the center of the block is mixed. A driving method is disclosed in which the number of pixels in the horizontal direction in the output video signal from the solid-state imaging device is reduced by mixing the signal charge with the signal charge of one pixel at the center of the adjacent block.
Japanese Patent Laid-Open No. 11-234688

  However, when sampling at the normal 1/3 frequency by thinning out or the like, the high frequency component is folded back at the Nyquist frequency 1 / 3F, so the (2/3) F component is added to the DC component. In the solid-state imaging device according to the conventional driving method, as shown in g1 of the graph showing the horizontal spatial frequency response in FIG. As a result, there is a problem that the image quality of the output video signal deteriorates due to the occurrence of moire or the generation of a false signal.

  Therefore, in view of such problems, the present invention has an object to provide a solid-state imaging device that can reduce the number of pixels in the horizontal direction and can output a high-quality video signal at high speed without generating moire or false signals. To do.

In view of the above circumstances, the present inventors have realized a solid-state imaging device capable of reducing the number of pixels in the horizontal direction, and capable of outputting a high-quality video signal at high speed without causing moire or false signals. Although not disclosed, the technology described in Japanese Patent Application No. 2002-328868 has already been proposed.
FIG. 1A is a schematic configuration diagram of a solid-state imaging device disclosed in Japanese Patent Application No. 2002-328868. FIG. 1B is a diagram for controlling reading of signal charges from the pixel unit 300 to the horizontal transfer unit 120. It is a schematic block diagram of the distribution transfer part 130 which has an independent drive electrode in the column direction.

  As shown in FIG. 1A, the solid-state imaging device shown in the above Japanese Patent Application No. 2002-328868 is two-dimensionally arranged corresponding to pixels, and is red (R), green (G) and blue ( B) a plurality of photoelectric conversion units 100 each having three color filters disposed thereon, and a CCD (Charge Coupled Device) having drive electrodes V1 to V6, V3R, V3L, V5R and V5L, and a drive pulse φV1 ˜V6, φV3R, φV3L, φV5R, and φV5L are constituted by a plurality of vertical transfer units 110 that transfer signal charges generated by the photoelectric conversion unit 100 in the column direction in response to the application, and a CCD that includes the drive electrodes H1 and H2. A horizontal transfer unit 120 that transfers signal charges in the row direction in response to application of drive pulses φH1 and φH2, and a plurality of photoelectric conversion units 100 and vertical transfer units 110 are formed. Distributing and transferring unit disposed between the imaging unit 140 and the horizontal transfer unit 120 and having independent drive electrodes formed in the column direction for controlling reading of signal charges from the pixel unit 300 to the horizontal transfer unit 120 130.

  As shown in FIG. 1B, the vertical transfer unit 110 of the distribution transfer unit 130 has the same electrode structure for every 2n + 1 (n is an integer of 1 or more) columns, and drive pulses φV1 to φV6, φV3R, φV3L. , .Phi.V5R and .phi.V5L are applied to a CCD having drive electrodes V1 to V6, V3R, V3L, V5R and V5L. Here, the drive electrodes V1, V2, V4, and V6 are common electrodes over all the columns, and the drive electrodes V3, V3R, V3L, V5, V5R, and V5L are independent electrodes separated into islands in each column, and are distributed and transferred. The unit 130 controls reading of signal charges from the vertical transfer unit 110 to the horizontal transfer unit 120 independently for each column.

  In the solid-state imaging device having the above-described configuration, the driving pulses are applied to the vertical transfer unit 110, the horizontal transfer unit 120, and the distribution transfer unit 130 according to the timing chart shown in FIG. Are mixed with signal charges of three pixels. When drive pulses φV1 to φV6, φV3R, φV3L, φV5R, and φV5L are at a high level, the drive electrode to which the drive pulse is applied becomes a storage unit, and drive pulses φV1 to φV6, φV3R, φV3L, φV5R, and φV5L In the case of a high level, the drive electrode to which the drive pulse is applied becomes a barrier portion.

  According to the solid-state imaging device having the above-described configuration, since signal charges are not discarded in pixel mixing, a video signal with high sensitivity can be obtained. Further, since the center of gravity of each mixed pixel group has an equal interval in the horizontal transfer unit, the 2 / 3F component becomes 0 as shown in g2 of the graph showing the horizontal spatial frequency response in FIG. Is almost eliminated, and an image signal with little moire and false signals can be obtained.

In the above description, the electrode structure having the same electrode structure with a cycle of 2n + 1 columns has been described. However, pixel mixing can be realized with a cycle of 2n (n is an integer of 1 or more) columns. However, moire and false signals become large.
However, in the solid-state imaging device, since the distribution transfer unit 130 includes a plurality of independent drive electrodes, the wiring transfer as shown in FIG. 12 in the past, that is, the horizontal transfer unit 120 is made of aluminum for light shielding. A layout in which the pixel portion 1200 including the sorting transfer portion 130 and the imaging portion 140 is covered with tungsten, and wirings connected to the independent electrodes V3, V3R, V3L, V5, V5R, and V5L are formed in the horizontal direction from the side of the pixel portion 1200. Then, since the distance between the pixel unit 1200 and the horizontal transfer unit 120 is short, it is difficult to realize the solid-state imaging device, and a new wiring layout is required.

  Based on the above knowledge, the present inventors have scrutinized the wiring layout in the distribution transfer unit of the solid-state imaging device, and have reached the present invention. In order to achieve the above object, a solid-state imaging device of the present invention generates a signal charge, transfers a signal charge in a column direction, and receives a signal charge from the pixel part and transfers the signal charge in a row direction. A solid-state imaging device including a transfer unit, wherein the pixel unit includes a plurality of independent drive electrodes in a column direction for controlling readout of signal charges from the pixel unit to a horizontal transfer unit, and the drive electrodes The first wiring connected to is formed on the horizontal transfer portion. Here, a first light shielding layer may be formed on the horizontal transfer unit, and the horizontal transfer unit may be shielded from light by the first wiring and the first light shielding layer.

As a result, independent electrode wiring can be formed regardless of the distance between the pixel portion and the horizontal transfer portion, so that the number of pixels in the horizontal direction can be reduced and high quality without causing moire or false signals. It is possible to realize a wiring layout of a solid-state imaging device that facilitates realization of a solid-state imaging device that can output a simple video signal at high speed.
The drive electrode and the first wiring are formed in different layers, and the pixel portion includes a first plug that vertically connects the drive electrode layer and the first wiring layer. A first flat electrode is formed below the drive electrode layer and the first wiring layer, and the first flat electrode is formed under the first plug under the first plug. It may have an area larger than the bottom surface of the plug. Here, the driving electrode and the first flat electrode may be different polysilicon layers.

In addition, a second light shielding layer may be formed on the pixel portion, and the second light shielding layer may have an opening at a position where the first plug is disposed.
As a result, the region excluding the plug connected to the drive electrode for controlling the signal readout from the pixel portion to the horizontal transfer portion is shielded, so that light is incident on the vertical transfer portion formed under the drive electrode. Can be prevented.

Since the contact between the independent electrode and the wiring can be stabilized and manufacturing variation can be prevented, damage such as yield can be greatly reduced, and a low-cost solid-state imaging device can be realized.
In addition, a first light shielding layer may be formed on the horizontal transfer unit, and the horizontal transfer unit may be shielded from light by the first wiring and the first light shielding layer. Here, the first wiring may be an aluminum layer, the first light shielding layer may be a tungsten layer, and the first wiring and the first light shielding layer may be different aluminum layers. It may be.

  As a result, the horizontal transfer unit is shielded by the light shielding layer and the wiring, so that it is possible to realize a solid-state imaging device that prevents deterioration in image quality caused by light entering the horizontal transfer unit.

  In addition, a third light shielding layer is formed on the pixel portion, and the second wiring connected to the driving electrode other than the driving electrode connected to the first wiring is connected to the third light shielding layer. A third wiring formed using part of the layer may be included.

  As a result, a part of the light-shielding layer is used as the wiring for the independent electrode, and it is not necessary to provide a new layer for the independent electrode to form the wiring, thereby suppressing an increase in cost without adding a new manufacturing process. be able to.

Further, it may be arranged so as not to intersect with the end portion of the drive electrode overlapping the end portion of the third wiring.
As a result, the end portions intersect, and a step portion having irregularities is formed at the intersecting portion, and the wiring cannot be performed according to the intended patterning at the intersecting portion, and an unnecessary pattern is formed. Therefore, it is possible to avoid an insulation failure that is not secured.

The second wiring may further include a fourth wiring, and at least a part of the fourth wiring may be formed along a signal charge transfer path of the pixel portion. Here, the third light shielding layer may be a tungsten layer, the fourth wiring may be an aluminum layer, and the third wiring and the fourth wiring may be two different layers. It may be a tungsten layer.
As a result, the vertical transfer unit is shielded by the wiring of the independent electrode, so that it is possible to realize a solid-state imaging device that prevents deterioration in image quality caused by light entering the vertical transfer unit.

  In addition, the third wiring and the fourth wiring are formed in different layers, respectively, and the pixel portion includes a second plug that connects the third wiring and the fourth wiring vertically. And a second flat electrode is formed under the third wiring and the fourth wiring, and the second flat electrode is formed under the second plug under the second plug. It may have a larger area than the bottom surface. Here, the second flat electrode is composed of two different polysilicon layers, and the first polysilicon layer has a larger area under the second plug than the bottom surface of the second plug. You may have a flat surface.

  As a result, the contact between the wirings can be stabilized and manufacturing variations can be prevented, so that damage such as yield can be greatly reduced, and a low-cost solid-state imaging device can be realized.

Further, a colored on-chip lens layer may be formed on the horizontal transfer unit, or a black on-chip lens layer may be formed on the drive electrode independent in the column direction, A plurality of, for example, R and B colors may be stacked to form an on-chip lens layer close to black.
As a result, it is possible to prevent light from entering the transfer unit without adding a new manufacturing process, and thus it is possible to realize a solid-state imaging device that can easily prevent deterioration in image quality.

The first wiring may include a plurality of wiring patterns, and a dummy wiring having substantially the same shape as at least one of the wiring patterns may be formed adjacent to the plurality of wiring patterns.
As a result, it is possible to realize a solid-state imaging device that can form the wiring of the independent electrode with high dimensional accuracy.

The independent drive electrodes in the column direction may have the same electrode structure for every n (n is an integer of 2 or more) columns.
As a result, the number of pixels in the horizontal direction can be reduced to 1 / n without discarding signal charges in pixel mixing, and the center of gravity of each mixed pixel group is equally spaced, resulting in moire and false signals. And a solid-state imaging device capable of outputting a high-quality video signal at high speed.

The present invention may be a camera including the solid-state imaging device according to any one of claims 1 to 18.
Thereby, since data is output from the solid-state imaging device at high speed, a camera capable of high-speed operation and excellent in image quality can be realized.

According to the solid-state imaging device according to the present invention, signal charges are not discarded in pixel mixing, and the center of gravity of each mixed pixel group is equally spaced in the horizontal transfer unit, so that the number of pixels in the horizontal direction is reduced, and There is an effect that it is possible to realize a solid-state imaging device capable of outputting a high-quality video signal at high speed without generating moire or a false signal. In addition, according to the solid-state imaging device according to the present invention, the wiring of the independent electrode can be formed regardless of the distance between the pixel unit and the horizontal transfer unit, thereby reducing the number of pixels in the horizontal direction, and There is an effect that it is possible to realize a wiring layout of the solid-state imaging device that facilitates realization of a solid-state imaging device capable of outputting a high-quality video signal at high speed without generating moire or false signals.
Further, according to the solid-state imaging device according to the present invention, a part of the light shielding layer made of tungsten and the light shielding layer made of aluminum are used as wirings connected to the independent electrode, and a new layer is formed for the independent electrode. Since there is no need to provide the wiring, it is possible to suppress an increase in cost without adding a new manufacturing process.

Further, according to the solid-state imaging device according to the present invention, the vertical transfer unit can be shielded by the wiring connected to the independent electrode, so that the solid-state that prevents the deterioration of the image quality caused by the light entering the vertical transfer unit is prevented. There is an effect that an imaging device can be realized.
In addition, according to the solid-state imaging device according to the present invention, it is possible to stabilize the contact in the region where the wires constituting the wire connected to the independent electrode are in contact with each other and the region where the independent electrode and the wire are in contact with each other. , Manufacturing variations can be prevented, and since the overlapping wiring and the end face of the drive electrode do not cross each other, they can be sufficiently electrically isolated, greatly reducing yield and other damage, and reducing the cost of solid-state imaging devices. There is an effect that it can be realized.

  Therefore, according to the present invention, it is possible to provide a solid-state imaging device capable of reducing the number of pixels in the horizontal direction and outputting a high-quality video signal at high speed without generating moire or false signals, and has practical value. high.

(First embodiment)
Hereinafter, solid-state imaging devices according to embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic configuration diagram of the solid-state imaging device according to the first embodiment, and FIG. 1B is a column direction for controlling reading of signal charges from the pixel unit 300 to the horizontal transfer unit 120. FIG. 1C is a schematic configuration diagram of the distribution transfer unit 130 having independent drive electrodes, and FIG. 1C is a schematic cross-sectional view of the distribution transfer unit 130.

  The solid-state imaging device of the present embodiment is intended to realize a solid-state imaging device that can reduce the number of pixels in the horizontal direction and can output a high-quality video signal at high speed without causing moire or false signals. As shown in FIG. 1 (a), three color filters of red (R), green (G), and blue (B) are arranged in two dimensions corresponding to the pixels. And a plurality of photoelectric conversion units 100 and a CCD having drive electrodes V1 to V6, V3R, V3L, V5R, and V5L, and photoelectrically responding to application of drive pulses φV1 to φV6, φV3R, φV3L, φV5R, and φV5L. It is composed of a plurality of vertical transfer units 110 that transfer signal charges generated by the conversion unit 100 in the column direction, and a CCD having drive electrodes H1 and H2, and applies drive pulses φH1 and φH2. In accordance with the horizontal transfer unit 120 that transfers signal charges in the row direction, the image pickup unit 140 formed with a plurality of photoelectric conversion units 100 and vertical transfer units 110, and the horizontal transfer unit 120. The distribution transfer unit 130 includes independent drive electrodes formed in the column direction for controlling reading of signal charges to the transfer unit 120.

  As shown in FIG. 1B, the vertical transfer unit 110 of the distribution transfer unit 130 has the same electrode structure for every 2n + 1 (n is an integer of 1 or more) columns, and drive pulses φV1 to φV6, φV3R, φV3L. , ΦV5R and φV5L are constituted by a CCD having drive electrodes V1 to V6, V3R, V3L, V5R and V5L. Here, the drive electrodes V1, V2, V4, and V6 are common electrodes over all the columns, and the drive electrodes V3, V3R, V3L, V5, V5R, and V5L are independent electrodes separated into islands in each column, and are distributed and transferred. The unit 130 controls reading of signal charges from the vertical transfer unit 110 to the horizontal transfer unit 120 independently for each column.

  In addition, as shown in FIG. 1C, the distribution transfer unit 130 includes a drive electrode having a two-layer structure in which a first layer polysilicon 150 and a second layer polysilicon 160 are stacked, The first wiring 170, which is an aluminum layer that also serves as a light shield for the vertical transfer unit 110, the second wiring 180, which is a tungsten layer, and the first wiring 170 and the second-layer polysilicon 160 made of tungsten. Alternatively, a plug 190 that electrically connects the second wiring 180 is formed.

  In the solid-state imaging device having the above-described configuration, the driving pulses are applied to the vertical transfer unit 110, the horizontal transfer unit 120, and the distribution transfer unit 130 according to the timing chart shown in FIG. Are mixed with signal charges of three pixels. When drive pulses φV1 to φV6, φV3R, φV3L, φV5R, and φV5L are at a high level, the drive electrode to which the drive pulse is applied becomes a storage unit, and drive pulses φV1 to φV6, φV3R, φV3L, φV5R, and φV5L In the case of a high level, the drive electrode to which the drive pulse is applied becomes a barrier portion.

FIG. 3 is a diagram showing an outline of the wiring layout of the solid-state imaging device according to the embodiment. The same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted here.
As shown in FIG. 3, in the solid-state imaging device of the embodiment, the portion of the imaging unit 140 excluding the photoelectric conversion unit 100 is covered with tungsten for light shielding, and the horizontal transfer unit 120 and the distribution transfer unit 130 are shielded from light. For this purpose, it is covered with tungsten and aluminum, and the horizontal transfer unit 120 is vertically connected from the bottom of the pixel unit 300 including the imaging unit 140 and the distribution transfer unit 130 to form wirings connected to the independent electrodes V5, V5R, and V5L. A wiring layout that forms wirings connected to the independent electrodes V3, V3R, and V3L in the horizontal direction from the side of the pixel portion 300 is used.

4 and 5 are diagrams showing details of the wiring layout of the distribution transfer unit 130, FIG. 4 shows the wiring layout of the layer made of polysilicon, and FIG. 5 shows the wiring layout of the layer made of tungsten and aluminum. Yes. 1 and 3 are denoted by the same reference numerals, and detailed description thereof will be omitted here.
As shown in FIG. 4, in the distribution transfer unit 130, the vertical transfer unit 110 is covered with the first wiring 170 and the light shielding layer 400 that is a tungsten layer, and from the side of the pixel unit 300 (from the lower side or the upper side in the drawing). The second wiring 180 is wired, the second wiring 180 and the first wiring 170 are brought into contact with each other by a plug 190 at an appropriate position 410, and the first wiring 170 and the second-layer polysilicon 160 are further contacted. Are connected to the independent electrodes V3, V3R, and V3L by opening the light-shielding layer 400 at a predetermined position 420 and making contact with the plug 190, and are formed from the bottom of the pixel portion 300 (right side in the drawing). One wiring 170 is wired, and the light shielding layer 400 is opened at the position 420 between the first wiring 170 and the second-layer polysilicon 160, and the plug 190. Wiring layout is used to form a wiring which is connected to the independent electrodes V5, V5R and V5L by more contacts.

Further, the second wiring 180 is arranged so that the end portions thereof do not intersect with the driving electrodes (lower side or upper side in the drawing) overlapping with the second wiring 180 shown in FIG.
Further, as shown in FIG. 5, in the distribution transfer unit 130, the second-layer polysilicon 160 is formed on the vertical transfer unit 110, thereby forming the independent electrodes V3, V3R, V3L, V5, V5R, and V5L. Then, a wiring layout is used in which a common electrode is formed by forming the first layer of polysilicon 150 over the entire vertical transfer portion 110.

FIG. 6 is a diagram illustrating details of the wiring layout of the horizontal transfer unit 120.
As shown in FIG. 6, in the horizontal transfer unit 120, the horizontal transfer unit 120 is covered with the first wiring 170 and the light-shielding layer 600 that is a tungsten layer for light shielding, and below the horizontal transfer unit 120 (on the left side in the figure). The wiring layout for forming the first wiring 170 on the horizontal transfer unit 120 is used so that the first wiring 170 wired from (1) is brought into contact with the second layer polysilicon 160 at the position 420.

FIG. 7A is a diagram showing details of the wiring layout (enlarged view of portion A in FIG. 5), and FIG. 7B is a detailed sectional view (cross section taken along the line cc ′ of FIG. 7A). 8A is a diagram showing details of the wiring layout (enlarged view of portion B in FIG. 5), and FIG. 8B is a detailed sectional view (d-- in FIG. 8A). It is sectional drawing in d 'line | wire.
As shown in FIG. 7B, the distribution transfer unit 130 at the position 410 has a first layer polysilicon 150, a second layer polysilicon 160, a second wiring 180, and a second wiring. The plug 190 that contacts the first wiring 170 and the first wiring 170 and the first wiring 170 are sequentially stacked.

Further, as shown in FIG. 8B, the distribution transfer unit 130 at the position 420, the first layer polysilicon 150, the second layer polysilicon 160, and the second layer polysilicon. The plug 190 that contacts the 160 and the first wiring 170 and the first wiring 170 are sequentially stacked.
Here, in each of the positions 410 and 420, the first-layer polysilicon 150 is located under the plug 190 and has a flat surface larger than the bottom area of the plug 190.

  As described above, according to the solid-state imaging device of the present embodiment, the number of pixels in the horizontal direction can be reduced to 1 / (2n + 1) without discarding signal charges in pixel mixing, and the horizontal transfer unit 120 can be reduced. , The center of gravity of each mixed pixel group is equally spaced. Therefore, the solid-state imaging device of the present embodiment can realize a solid-state imaging device capable of outputting a high-quality video signal at high speed without generating moire or a false signal.

  Further, according to the solid-state imaging device of the present embodiment, the wiring connected to the independent electrodes V5, V5R, and V5L is formed through the horizontal transfer unit 120 from the bottom of the pixel unit 300 in the vertical direction. Accordingly, since the wiring connected to V5, V5R, and V5L can be formed regardless of the distance between the pixel portion and the horizontal transfer portion, the solid-state imaging device according to the present embodiment has the number of pixels in the horizontal direction. In addition, it is possible to realize a wiring layout of a solid-state imaging device that facilitates the realization of a solid-state imaging device that can output high-quality video signals at high speed without generating moire or false signals.

  In addition, according to the solid-state imaging device of the present embodiment, a part of the light shielding layer made of tungsten that has been conventionally used only for light shielding of the pixel unit 300 is connected to the independent electrodes V3, V3R, and V3L. Use as wiring. Therefore, since there is no need to provide a new layer and form a wiring for the independent electrodes V3, V3R, and V3L, the solid-state imaging device according to the present embodiment suppresses an increase in cost without adding a new manufacturing process. can do.

  Further, according to the solid-state imaging device of the present embodiment, the first wiring 170 serves not only as the wiring of the sorting and transferring unit 130 but also as a light shielding. Therefore, since the vertical transfer unit of the distribution transfer unit can be shielded by the first wiring, the solid-state imaging device according to the present embodiment prevents deterioration in image quality caused by light entering the vertical transfer unit 110. The solid-state imaging device can be realized.

  Further, according to the solid-state imaging device of the present embodiment, the independent electrode V <b> 5 that also serves as the light-shielding layer of the horizontal transfer unit 120 is used as the light-shielding layer made of aluminum that has been conventionally used only for light shielding of the horizontal transfer unit 120. , Used as wiring connected to V5R and V5L. Therefore, since there is no need to provide a new layer and form a wiring for the independent electrodes V5, V5R, and V5L, the solid-state imaging device of the present embodiment suppresses an increase in cost without adding a new manufacturing process. can do.

  Further, according to the solid-state imaging device of the present embodiment, the first layer polysilicon 150 has a larger area than the bottom surface of the plug 190 at the position 410 where the first wiring 170 and the second wiring 180 are in contact. The first-layer polysilicon 150 has a larger area than the bottom surface of the plug 190 at a position 420 where the first wiring 170 and the second-layer polysilicon 160 are in contact with each other. It has a flat surface. Therefore, the second wiring and the second-layer polysilicon have a flat surface with an area larger than the bottom surface of the plug, so that the contact can be stabilized, manufacturing variations can be prevented, and overlapping wirings can be obtained. Since the electrodes are arranged so that the end surfaces of the drive electrodes do not cross each other, they can be sufficiently electrically isolated, so that the solid-state imaging device of this embodiment significantly reduces damage such as yield and realizes a low-cost solid-state imaging device The effect that it can be done is produced.

In the solid-state imaging device of this embodiment, the horizontal transfer unit 120 is shielded by the light shielding layer 600 that is a tungsten layer and the first wiring 170 that is an aluminum layer. However, the horizontal transfer unit may be formed of aluminum having a two-layer structure, and the horizontal transfer unit may be shielded from light by a light shielding layer that is an aluminum layer and a first wiring that is an aluminum layer.
In the solid-state imaging device of the present embodiment, wirings connected to the independent electrodes V3, V3R, and V3L are formed by the first wiring 170 that is an aluminum layer and the second wiring 180 that is a tungsten layer. However, tungsten having a two-layer structure is formed on the distribution transfer portion, and wirings connected to the independent electrodes V3, V3R, and V3L are formed by the first wiring that is the tungsten layer and the second wiring that is the tungsten layer. May be.

  In addition, an on-chip lens layer may be formed on the horizontal transfer unit 120, or a black on-chip lens layer may be formed on the distribution transfer unit 130. Further, the black on-chip lens layer may be a lens layer close to black in which a plurality of colors are stacked, for example, R and B are stacked. At this time, the on-chip lens layer is formed, for example, in the process of forming the color film of the photoelectric conversion unit. As a result, it is possible to prevent the light from entering the transfer unit without adding a new manufacturing process, and thus it is possible to easily prevent the image quality from being deteriorated.

Further, as shown in the top view of the horizontal transfer unit 120 in FIG. 9, the first transfer line 170 on the horizontal transfer unit 120 and the other line having a width larger than the first transfer line 170 may be A dummy wiring 900 having substantially the same shape as at least one of the one wiring 170 may be formed. As a result, the first wiring can be formed with high dimensional accuracy.
In the above-described embodiment, the electrode structure having the same electrode structure with a period of 2n + 1 columns has been described. However, pixel mixing can be realized with a period of 2n (n is an integer of 1 or more) columns.
The color filter has been described as an RGB three-color filter, but may be a four-color filter such as cyan, magenta, yellow, and green.

(Second Embodiment)
Hereinafter, a camera equipped with a solid-state imaging device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 10 is a block diagram of a camera according to the second embodiment.
As illustrated in FIG. 10, the camera includes a lens 1000, a solid-state imaging device 1010, a drive circuit 1020, a signal processing unit 1030, and an external interface unit 1040.
In the camera having the above configuration, processing until a signal is output to the outside is performed in the following order.
(1) Light passes through the lens 1000 and enters the solid-state imaging device 1010.
(2) The signal processing unit 1030 drives the solid-state imaging device 1010 through the drive circuit 1020 and takes in an output signal from the solid-state imaging device 1010.
(3) The signal processed by the signal processing unit 1030 is output to the outside through the external interface unit 1040.

  As described above, according to the camera of the present embodiment, data is output from the solid-state imaging device at high speed. Therefore, the camera of this embodiment can realize a camera that can operate at high speed and has excellent image quality.

  The present invention can be used for a solid-state imaging device, and in particular, can be used for a digital still camera or the like.

(A) It is a schematic block diagram of the solid-state imaging device of the 1st Embodiment of this invention. (B) It is a schematic block diagram of the distribution transfer part 130 of the solid-state imaging device of the embodiment. (C) It is a schematic sectional drawing of the distribution transfer part 130 of the solid-state imaging device of the embodiment. It is an operation | movement timing chart in the case of performing pixel mixing of the solid-state imaging device of the embodiment. It is a figure which shows the outline of the wiring layout of the solid-state imaging device of the embodiment. It is a figure which shows the detail of the wiring layout of the layer which consists of polysilicon of the solid-state imaging device of the embodiment. It is a figure which shows the detail of the wiring layout of the layer which consists of tungsten and aluminum of the solid-state imaging device of the embodiment. It is a figure which shows the detail of the wiring layout of the horizontal transfer part 120 of the solid-state imaging device of the embodiment. (A) It is a figure (detailed drawing of the A section of FIG. 5) which shows the detail of the wiring layout of the distribution transfer part 130 of the solid-state imaging device of the embodiment. FIG. 8B is a detailed cross-sectional view (cross-sectional view taken along the line c-c ′ in FIG. 7A) of the distribution transfer unit 130 of the solid-state imaging device according to the embodiment. (A) It is a figure (the enlarged view of the B section of FIG. 5) which shows the detail of the wiring layout of the distribution transfer part 130 of the solid-state imaging device of the embodiment. FIG. 8B is a detailed cross-sectional view (cross-sectional view taken along the line d-d ′ in FIG. 7A) of the distribution transfer unit 130 of the solid-state imaging device according to the embodiment. It is a top view of the horizontal transfer part 120 of the solid-state imaging device of the embodiment. It is a block diagram of the camera of a 2nd embodiment. It is a graph which shows the horizontal spatial frequency response of the solid-state imaging device of 1st Embodiment. It is a figure which shows the outline of the wiring layout of the conventional solid-state imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Photoelectric conversion part 110 Vertical transfer part 120 Horizontal transfer part 130 Distribution transfer part 140 Image pick-up part 150 1st layer polysilicon 160 2nd layer polysilicon 170 1st wiring 180 2nd wiring 190 Plug 300, 1200 Pixel unit 400, 600 Light blocking layer 410, 420 Position 900 Dummy wiring 1000 Lens 1010 Solid-state imaging device 1020 Drive circuit 1030 Signal processing unit 1040 External interface

Claims (19)

A solid-state imaging device comprising: a pixel unit that generates a signal charge and transfers the signal charge in a column direction; and a horizontal transfer unit that receives the signal charge from the pixel unit and transfers the signal charge in a row direction.
The pixel unit includes a plurality of independent drive electrodes in a column direction for controlling readout of signal charges from the pixel unit to a horizontal transfer unit,
The solid-state imaging device, wherein the first wiring connected to the drive electrode is formed on the horizontal transfer unit. A first light shielding layer is formed on the horizontal transfer unit,
The solid-state imaging device according to claim 1, wherein the horizontal transfer unit is shielded from light by the first wiring and the first light shielding layer. The first wiring is composed of a plurality of wiring patterns,
2. The solid-state imaging device according to claim 1, wherein a dummy wiring having substantially the same shape as at least one of the wiring patterns is formed adjacent to the plurality of wiring patterns. The first wiring is an aluminum layer;
The solid-state imaging device according to claim 2, wherein the first light shielding layer is a tungsten layer. The solid-state imaging device according to claim 2, wherein the first wiring and the first light shielding layer are different aluminum layers. The drive electrode and the first wiring are formed in different layers,
The pixel portion includes a first plug that vertically connects the drive electrode layer and the first wiring layer;
A first flat electrode is formed under the drive electrode layer and the first wiring layer,
The solid-state imaging device according to claim 1, wherein the first flat electrode has an area larger than a bottom surface of the first plug under the first plug. A second light shielding layer is formed on the pixel portion,
The solid-state imaging device according to claim 6, wherein the second light shielding layer has an opening at a position where the first plug is disposed. The solid-state imaging device according to claim 6, wherein the drive electrode and the first flat electrode are respectively different polysilicon layers. A third light shielding layer is formed on the pixel portion,
The second wiring connected to the driving electrode other than the driving electrode connected to the first wiring includes a third wiring formed using a part of the third light shielding layer. The solid-state imaging device according to claim 1 or 8. 10. The solid-state imaging device according to claim 9, wherein an end of the third wiring does not intersect with an end of an overlapping drive electrode among the plurality of drive electrodes. The second wiring further includes a fourth wiring,
The solid-state imaging device according to claim 9, wherein at least part of the fourth wiring is formed along a signal charge transfer path of the pixel portion. The third wiring and the fourth wiring are formed in different layers,
The pixel portion includes a second plug that connects the third wiring and the fourth wiring vertically,
A second flat electrode is formed under the third wiring and the fourth wiring,
The solid-state imaging device according to claim 11, wherein the second flat electrode has a larger area under the second plug than a bottom surface of the second plug. The second flat electrode is composed of two different polysilicon layers,
13. The solid-state imaging device according to claim 12, wherein the first polysilicon layer has a flat surface with an area larger than a bottom surface of the second plug under the second plug. The third light shielding layer is a tungsten layer;
The solid-state imaging device according to claim 11, wherein the fourth wiring is an aluminum layer. The solid-state imaging device according to claim 11, wherein the third wiring and the fourth wiring are two different tungsten layers. (The drive electrode is an independent electrode)
The solid-state imaging device according to claim 1, wherein the drive electrodes independent in the column direction have the same electrode structure for every n (n is an integer of 2 or more) columns. The solid-state imaging device according to claim 1, wherein a black on-chip lens layer is formed on the drive electrodes independent in the column direction. The solid-state imaging device according to claim 1, wherein a colored on-chip lens layer is formed on the horizontal transfer unit. A camera comprising the solid-state imaging device according to claim 1.

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