JPH09246517A - Amplification type solid-state image sensor - Google Patents

Abstract

(57) Abstract: In an amplification type solid-state imaging device, by reducing the capacitance and resistance of the horizontal read line and arranging the sizes, delay and loss of the output signal are reduced, and fixed pattern noise is canceled. Increase. In an amplification type solid-state imaging device, a bridging portion 19a between a horizontal switch element 5 and a corresponding horizontal readout line 3 is connected by using aluminum wiring. Further, the horizontal read lines 3 and the horizontal switch elements are alternately arranged, and the horizontal switch elements 5 are adjacent to the corresponding horizontal read lines 3, whereby the horizontal read lines 3 are arranged.
The connection wiring between the horizontal switch 5 and the horizontal switch 5 is shortened, and variations in resistance and capacitance between wirings are suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplification type solid-state image pickup device, and more particularly, by reducing the capacitance and resistance of the horizontal read line and eliminating the line-to-line variation, the loss and size variation of the output signal can be reduced. Regarding technology to reduce.

[0002]

2. Description of the Related Art An amplification type solid-state image pickup device uses, for example, a pixel composed of an electrostatic induction transistor (SIT) or a plurality of MOS transistors, and the pixel converts the image light of a subject into an electric signal, amplifies and outputs the electric signal. Is what you can do. In the amplification type solid-state image sensor, unlike the CCD solid-state image sensor, the signal output of the pixels arranged in a matrix is sequentially sent to the vertical signal line for each row, and the horizontal signal is further read horizontally in the horizontal direction from the vertical signal line. It is connected to the line and output.

Further, in the amplification type solid-state image pickup device, noise called fixed pattern noise (FPN) is apt to occur due to variations in the light receiving elements and the amplification elements forming the pixels. As one method for correcting fixed pattern noise, there is a method in which both the dark state output (Vdark) and the bright state output (Vsig) are read from each pixel and the difference between them is used as a signal output. In this way,
Generally, two horizontal read lines are required for the dark signal and the bright signal. Further, in general, since odd-numbered pixels and even-numbered pixels in the horizontal direction are simultaneously read as channel 1 and channel 2 for speeding up, lines for dark signal (Vdark) and bright signal (Vsig) are used for each. In that case, a total of four horizontal read lines are required.

FIG. 7 shows an example of a circuit configuration in the vicinity of a horizontal read line of such an amplification type solid-state image pickup device. The amplification type solid-state imaging device of FIG. 7 includes a pixel matrix 1 configured by amplification type photoelectric conversion pixels arranged in the row and column directions, a horizontal readout line 3 having, for example, a total of four lines, and a horizontal readout switch. A group 5, a storage capacitor group 7, a signal transfer switch group 9, a horizontal shift register 11, and an output amplifier group 12 are provided.

The horizontal read line 3 is provided with a dark signal line HL1D and a bright signal line HL1S of the channel 1, a dark signal line HL2D and a bright signal line HL2S of the channel 2. The vertical signal line 13 extending in the vertical direction from the pixel matrix 1 and connected to the pixels in each column is connected to the dark signal transfer switch QTD and the bright signal transfer switch QTS in each column by the vertical signal line 15 to store the dark signal storage capacitance. It is connected to one terminal of the CTD and the bright signal storage capacitor CTS. (Although 13 and 15 are different wirings, they are called with the same name for convenience.) The other terminals of these storage capacitors CTD and CTS are connected to, for example, the ground. The one terminal of each of the storage capacitors CTD and CTS is connected to the dark signal line HL1D of the channel 1 of the horizontal read line 3 by the vertical connection line 17 via the dark signal horizontal switch QHD and the bright signal horizontal switch QHS, respectively. It is connected to the bright signal line HL1S or the dark signal line HL2D and the bright signal line HL2S of the channel 2.

In the amplification type solid-state image pickup device having such a configuration, first, the dark signal transfer switch QTD is turned on by the control pulse φTD, and the dark signal from the pixel of the selected row in the pixel matrix 1 is supplied to each vertical signal line 13. And is stored in the dark signal storage capacitor CTD. After the transfer operation is completed, QTD is turned off. Then, the pixels in the selected row of the pixel matrix 1 are set to the signal output state, and the signal transfer switches QTS are set by the control signal φTS.
Is turned on, the signal output from the pixel in the selected row is transferred through each vertical signal line 13, and is stored in the signal storage capacitor CTS. After the transfer operation is completed, the QTS is turned off. During these operations, the dark signal horizontal switch QHD and the bright signal horizontal switch QHS are kept in the off state.

Next, with the dark signal transfer switch QTD and the bright signal transfer switch QTS being kept off, a read control signal from the horizontal shift register 11, for example, φH.
m are sequentially supplied, and signals are sequentially read out for every two channels. That is, for example, the horizontal switches QHD and QHS for the dark signal and the bright signal for two channels are turned on by the horizontal read pulse φHm, and the dark signal charge and the bright signal from the dark signal storage capacitor CTD and the bright signal storage capacitor CTS are turned on. The charges are transferred to the dark signal line HL1D and the bright signal line HL1S or the dark signal line HL2D and the bright signal line HL2S of the horizontal read line 3, respectively. The dark signal and the bright signal of channel 1 are respectively the dark signal line HL1D and the bright signal line HL1S.
To the dark signal output VO from each output amplifier 12
1D and a bright signal output VO1S. Further, the dark signal and the bright signal of the channel 2 are output as the dark signal output VO2D and the bright signal output VO2S from the dark signal line HL2D and the bright signal line HL2S via the output amplifiers 12 respectively. Therefore, in each channel 1 and 2, if the dark signal output is subtracted from the bright signal output, a signal output with fixed pattern noise corrected can be obtained. That is, in channel 1, VO1S-VO
1D becomes a signal output, and VO2S-VO on channel 2
2D becomes a signal output.

FIG. 8 shows a wiring pattern on the integrated circuit from the horizontal switch 5 to the horizontal read line 3 of the solid-state image sensor shown in FIG. 8, parts corresponding to the components shown in FIG. 7 are indicated by the same reference numerals or symbols. In addition, FIG.
FIG. 3 shows a sectional view along the line.

In the solid-state image sensor shown in FIGS. 8 and 9, the vertical signal line 13 (FIG. 7) and the horizontal read line 3 are used.
Is formed by using the first layer of aluminum. Further, the vertical signal line 15 connected to each vertical signal line 13 via the signal transfer switch 9 (FIG. 7) and the vertical connection line 17 extending from each horizontal switch 5 to the horizontal read line 3 are also formed by using the first layer aluminum. ing.

However, in order to connect the vertical connection line 17 and the horizontal read line 3 to each other, a bridging portion of the wiring is required. Polycrystalline silicon (polysilicon) wiring is used for the bridging portion 19 of these wirings to make so-called cross-under connection. The polysilicon wiring 19 is formed below the vertical connection line 17 via an insulating film 21. In addition, each polysilicon wiring 1
In order to eliminate the line-to-line variation in the wiring resistance of 9, all the bridging portions 19 have the same length, and the lines that do not need to be bridged are intentionally bridged.

The portion including the horizontal switches 5 is covered with a light-shielding aluminum 23 made of a second layer of aluminum. The light-shielding aluminum 23 is provided to prevent the horizontal switch 5 or the like from malfunctioning due to the incident light.

Each of the MOS transistors QHD and QHS forming the horizontal switch 5 has a substantially U-shaped drain 27 and a source 29 formed at the center thereof, as shown in detail in FIG. I have it. The drain 27 and the source 29 are connected to the vertical signal line 15 and the vertical connection line 17 via contact holes 31 and 33, respectively. Further, on the substrate between the drain 27 and the source 29, a gate wiring 35 also serving as an annular gate electrode is formed of polysilicon via an insulating film (not shown). The gate wirings 35 are connected together for every four horizontal switching transistors for two channels and are connected to the horizontal shift register 11 (FIG. 7).

[0013]

In the conventional solid-state image pickup device having the above-mentioned structure, since the bridging portion from the horizontal switch 5 to the horizontal read line 3 is formed by using the polysilicon wiring, it is various. Inconvenience has occurred.

As described above, the storage capacitors CTD and C
The charge accumulated in TS is applied to each horizontal switch QHD.
When the QHS and QHS are sequentially turned on to read out to the horizontal read line 3, the output signal is lost due to the capacitance of the horizontal read line 3. Now, for example, each storage capacity CTD,
The capacitances of the CTS are the same and the value is CT, and the capacitance of one horizontal line of the horizontal read line 3 is C.
H. At this time, the signal charge of the storage capacitor CTD or CTS is distributed by the capacitors CT and CH, and CT /
It becomes (CT + CH) times smaller and is transmitted to the input section of the output amplifier 12. Therefore, in order to reduce the loss of charge, it is preferable that the value of the capacitor CH is small.

The value of the capacitance CH of the horizontal read line is [capacitance by the horizontal read line 3] and [capacitance of the source 29 of the horizontal switching transistors QHD and QHS] × [1
Number of horizontal switch transistors QH per line]
And [capacity due to bridging part] x [Q per line
The number of H]. In this case, [capacitance due to horizontal read line 3] and [capacity due to bridging part] are
Each of them has two components, that is, a capacitance formed between the horizontal read line and the conductive layer of the bridging portion with the underlying portion such as the substrate 25, and a capacitance formed between the conductive layer and the light shielding aluminum 23.

Therefore, if the bridging portion 19 is formed by using the polysilicon wiring, the following problems occur. (1) Since polysilicon with high resistance is used for wiring,
Not only the capacitance (CH) of the horizontal read line, but also the voltage division and the signal delay of the signal due to the wiring resistance (RH) of the horizontal read line are not negligible and become a problem. (2) In order to reduce the resistance of the bridging portion 19, the wiring may be thickened, but thickening the wiring conversely increases the capacitance of the bridging portion 19. Therefore, the time constant (CH ×
RH) cannot be made too small. (3) The horizontal read line capacitance CH is different for each horizontal read line because the aluminum wiring length from the bridge portion 19 of polysilicon to the source 29 of the horizontal switch transistor 5 is different for each horizontal read line. For this reason,
The output size varies from line to line. This causes an error in the subtraction of (Vsig-Vdark), which makes it impossible to appropriately cancel fixed pattern noise, or causes a difference in the output levels of channel 1 and channel 2.

Therefore, the object of the present invention has been made in view of the problems in such a conventional apparatus,
By reducing the horizontal read line capacitance (CH) and resistance (RH), eliminating the loss and delay of the output signal,
It is to realize a high-sensitivity solid-state imaging device.

Another object of the present invention is to more appropriately remove fixed pattern noise and reduce variations in output for each channel by making the sizes of the capacitance CH and the resistance RH for each horizontal read line uniform. It is in.

[0019]

In order to achieve the above object, in an amplification type solid-state image pickup device according to the present invention, signals from a plurality of amplification type pixels for accumulating and amplifying signal charges corresponding to respective optical signals are provided in each row. A plurality of vertical signal lines sequentially output for each, a horizontal read line for sequentially selecting and outputting the signal from each vertical signal line, connected between the vertical signal line and the horizontal read line, A horizontal switch element that sequentially couples the signal from the vertical signal line to the horizontal read line is provided for each column, and a bridge portion between the horizontal switch element and the horizontal read line is connected using aluminum wiring. .

In such a configuration, signals from a plurality of amplification type pixels are sequentially coupled to the horizontal read line by the horizontal switch element and output, whereby signal reading in the horizontal scanning line direction is performed. In this case, the connection of the bridging portion between the horizontal switch element and the horizontal read line is made by using aluminum wiring instead of the polysilicon which has been conventionally used, so that the resistance of the wiring connection at the bridging portion is significantly increased. It can be reduced. Therefore, a sufficiently low wiring resistance can be obtained even if the wiring width of the bridging portion is narrowed, so that the capacitance between the bridging portion and the substrate and the like can be reduced. Therefore, the time constant of the circuit from the horizontal switch element to the horizontal read line can be reduced, and the delay of the output signal and the signal loss due to charge distribution by the capacitance can be significantly reduced.

In this case, at least the light-shielding aluminum near the bridging portion extending from the horizontal switch element to the horizontal read line is eliminated, and an aluminum layer forming the light-shielded aluminum is used to provide a space between the horizontal switch element and the horizontal read line. You can also connect the bridging part of.

As a result, the light-shielding aluminum in the vicinity of the bridging portion from the horizontal switch element to the horizontal read line is eliminated, so that a strong light hitting the vicinity of the horizontal switch element may cause malfunction. However, when such an amplification type solid-state imaging device is used as an electronic still camera with a mechanical shutter, the reading operation starts after the shutter is closed after exposure. Therefore, the horizontal switching element is not exposed to light during operation. Moreover, since the signal read circuit is reset immediately before the signal is transferred from the pixel section to the horizontal read circuit such as the horizontal read line via the vertical signal line, the light incident on the horizontal switch element section at the time of exposure is prevented. It does not affect the horizontal read output. Therefore, for example, when the electronic still camera with such a mechanical shutter is used, there is no problem even if the light-shielding aluminum near the horizontal read switch element is eliminated.

Further, the vertical signal line and the horizontal read line are formed by a first layer aluminum, and the bridge portion between the horizontal switch element and the horizontal read line is connected by using a second layer aluminum. You can also

In this case, if the second-layer aluminum for connecting the bridging portions is the light-shielding aluminum, there is a problem if the solid-state image pickup element is used in an electronic still camera with a mechanical shutter as described above. There is no. Further, it is also possible to shield light by using another light shielding layer on the second layer aluminum, for example, a third layer aluminum or a black filter.

In the amplification type solid-state image pickup device according to another aspect of the present invention, a plurality of vertical signals for sequentially outputting, for each row, signals from a plurality of amplification type pixels for accumulating and amplifying signal charges corresponding to respective optical signals. Line, at least one set of horizontal read lines for dark signal and read signal for sequentially outputting the dark signal and the read signal of the pixel from each vertical signal line, respectively, and provided for each vertical signal line. Two storage capacitors for storing a signal charge and a read signal charge, a transfer switch element for selectively connecting each vertical signal line to the dark signal storage capacitor or the read signal storage capacitor, and the dark switch of each column. A horizontal switch element for sequentially coupling the signal storage capacitor and the read signal storage capacitor to the dark signal read horizontal lines and the read signal horizontal read lines, respectively. Line and the horizontal read lines is formed by a first layer aluminum, and connecting the bridging portion between the said horizontal switching element horizontal read line is carried out in the second layer aluminum.

In such an amplification type solid-state image pickup device, a dark signal and a read signal or a bright signal from each pixel to each vertical signal line for each row are stored in the dark signal storage capacitor and the read signal via the transfer switch element. Is stored in the storage capacity for storage. Then, they are transferred from the respective storage capacitors to the horizontal read lines for the dark signal and the read signal through the respective horizontal switch elements and the bridging connection wirings and outputted.

In this case, the vertical signal lines and the horizontal read lines for the dark signal and the read signal are formed of the first layer aluminum, and the horizontal switch elements for the dark signal and the read signal and the corresponding horizontal read lines are provided. By connecting the respective bridging portions with the second layer aluminum, the wiring resistance and capacitance of these bridging portions can be reduced. Therefore, the capacitance and resistance of each horizontal read line can be reduced to reduce the delay of the output signal and the signal loss. Further, since there are horizontal read lines for dark signals and read signals, and a plurality of horizontal read lines for these dark signals and read signals are provided as necessary, the length of the bridging portion becomes long. However, the wiring resistance and the capacitance rarely increase, so that the delay of the output signal and the signal loss can be reduced even in such a case.

The amplification type pixels may be arranged two-dimensionally in the row and column directions. In this case, the amplification type solid-state image pickup device serves as an image sensor for an electronic still camera, various image pickup devices, and image input. It can be used for devices.

When the second layer aluminum is used for connecting the bridging portion between the horizontal switch element and the horizontal read line, the second layer aluminum can be used for any purpose other than the connecting portion of the bridging portion. It can also be used, for example, for shielding light at desired portions, and the influence of irradiation of light on those portions can be eliminated.

In an amplification type solid-state image pickup device according to still another aspect of the present invention, a plurality of signals from a plurality of amplification type pixels for respectively accumulating and amplifying signal charges corresponding to optical signals are sequentially output for each row. A vertical signal line, a horizontal read line for sequentially selecting and outputting signals from the vertical signal lines, and a signal from the vertical signal line connected between the vertical signal line and the horizontal read line. A horizontal switch element sequentially connected to the horizontal read line is provided for each column,
By arranging the horizontal read lines and the horizontal switch elements in an alternating manner, and by arranging a horizontal switch element connected to the horizontal read line adjacent to the horizontal read line, a wiring connecting the horizontal read line and the horizontal switch element is formed. Shorten the distance.

In such a configuration, since the horizontal read line and the horizontal switch connected to the horizontal read line are arranged adjacent to each other, the wiring connecting the horizontal read line and the horizontal read switch element is shortened, and The wiring length can be made uniform. Therefore, the size of the capacitance and the resistance can be made uniform for each horizontal read line, and the variation in the output size for each line can be reduced. As a result, by obtaining the dark signal and the read signal from each pixel and taking the difference between the dark signal and the read signal, it is possible to significantly increase the fixed pattern noise removal rate even in the solid-state imaging device that removes the fixed pattern noise.

In such a configuration, the vertical signal line and the horizontal read line are formed of the first layer aluminum, and the horizontal switch element corresponding to the horizontal read line is directly connected by the first layer aluminum without bridging. You can Therefore, the capacitance and resistance of each horizontal read line can be made extremely small, and the delay of the output signal and the signal loss can be greatly reduced.

Further, in this case, by connecting the horizontal switch element and the corresponding vertical signal line with the second layer aluminum, the resistance and capacitance between the horizontal switch element and the vertical signal line are reduced, and the delay of the output signal is delayed. Moreover, the signal loss can be further reduced.

When the horizontal switch element and the vertical signal line are connected by the second layer aluminum, the necessary area other than this connecting portion can be shielded by using the second layer aluminum. It is possible to eliminate the adverse effect of the irradiation of light on the.

Alternatively, the horizontal switching element and the corresponding vertical signal line may be connected by a polycrystalline silicon layer, and the second layer aluminum may shield the horizontal switching element portion. A capacitance for accumulating charges of a dark signal or a read signal is connected to the vertical signal line, and each vertical signal line is driven by an amplification type pixel. Therefore, even if the capacitance of the vertical signal line increases, it works as a part of the capacitance for accumulating charges, and therefore, there is no loss of signal charges. Further, since the horizontal switch element and the vertical signal line are connected to each other by the polycrystalline silicon layer, the second layer aluminum can be used to shield the horizontal switch element portion, and the element is stable against incident light. Can be realized.

Further, the horizontal switching element portion can be shielded from light by using a third layer aluminum or a black filter. In these cases, the first layer aluminum and the second layer aluminum can be utilized for the connection between the horizontal switch element and the horizontal read line, the connection between the horizontal switch element and the vertical signal line, and the like, and the high performance and the incident light can be obtained. A stable element can be realized.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION An amplification type solid-state image pickup device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a wiring pattern on an integrated circuit in a portion from a horizontal switch 5 to a horizontal read line 3 of an amplification type solid-state imaging device according to a first embodiment of the present invention. The structure of FIG. 1 corresponds to the circuit shown in FIG. 7, and the same parts are designated by the same reference numerals. 2 shows a sectional view taken along the line AA of FIG.

In the solid-state image pickup device shown in FIGS. 1 and 2, the vertical signal line 13 (FIG. 7) and the horizontal read-out line 3 are the first as in the conventional solid-state image pickup device shown in FIGS. 8 and 9. It is formed by using a layer of aluminum. Further, the vertical signal line 15 connected to each vertical signal line 13 via the signal transfer switch 9 (FIG. 7) and the vertical connection line 17a at a portion extending from each horizontal switch 5 to the horizontal read line 3 (these are vertical as described above). (It may be considered as a part of the signal line 13) is also formed by using the first layer aluminum.

However, in order to connect the vertical connection line 17a and the horizontal read line 3 to each other, there is a portion where a wiring bridging portion is required. Bridging part 1 of these wirings
In the present embodiment, 9a is formed by using the second layer aluminum. That is, the vertical connection line 17a is connected to the bridging portion 19a via the through hole 20, and the bridging portion 19a is connected to the horizontal read line 3 via another through hole 20. That is, the bridging portion of the wiring that was conventionally connected by polysilicon is used as the second layer aluminum 1
9a is connected.

As a result, the resistance from the horizontal switch 5 to the horizontal read line, that is, the horizontal read line resistance (R
H) can be reduced, the capacitance between the horizontal read line and the light-shielding aluminum is eliminated, and the horizontal read line capacitance (CH) is also reduced. As a result, it is possible to reduce loss of signal output and signal delay. Other parts are the same as those shown in FIG. 8, and the same parts are denoted by the same reference numerals.

In the structure shown in FIG. 1, since the light-shielding aluminum is eliminated, strong light on the part of the MOS transistor forming the horizontal switch 5 may cause malfunction. However, when such an amplification type solid-state imaging device is used as an electronic still camera with a mechanical shutter, the reading operation starts after the shutter is closed after exposure. That is, since the shutter is closed during the operation of the horizontal switch 5, no light is emitted. Moreover, the horizontal read line is reset by a reset circuit (not shown) immediately before the signal is transferred from the pixel section to the horizontal read circuit section. Therefore, the influence of the light incident on the horizontal switch 5 portion at the time of exposure is eliminated. Therefore, when used as an electronic still camera with a mechanical shutter, there is no problem even if the horizontal switch 5 is not shielded.

FIG. 3 shows a horizontal read line 3 from the horizontal switch 5 of the solid-state image sensor according to the second embodiment of the present invention.
The structure of the part up to is shown. In the structure of FIG. 3, as in the case of FIG. 1, light shielding by the second layer aluminum is eliminated, and each line of the horizontal read line 3 and the MOS transistor of the horizontal switch 5 are arranged alternately.
For this reason, in the solid-state imaging device according to the conventional example and the first embodiment, wiring is bridged on the source 29 side of each horizontal switch 5 in order to connect the horizontal switch 5 and the horizontal read line. In this embodiment, the source 29 of the MOS transistor of each horizontal switch 5 is the first layer aluminum and is directly connected to the corresponding horizontal read line at a short distance. Accordingly, in order to connect the vertical signal line 15a and each horizontal switch 5, each horizontal switch 5
Wiring is bridged by the bridging wiring 37 on the drain 27 side. The bridging wiring 37 is made of the second layer aluminum in the embodiment of FIG. Therefore, the second layer of light-shielding aluminum is eliminated, but there is no problem when it is used in an electronic still camera with a mechanical shutter as described above.

In the solid-state image sensor according to the second embodiment shown in FIG. 3, the connecting portion 17b between each horizontal switch 5 and the horizontal read line 3 can be significantly shortened, and the first layer aluminum is used. Can be connected as it is and the line width can be reduced.
This is because the line width cannot be reduced to some extent because a through hole is required when bridging with polysilicon or the second layer aluminum. Therefore, according to the structure of FIG. 3, not only the horizontal read line resistance (RH) can be reduced, but also the horizontal read line capacitance (CH) can be significantly reduced. Also, the horizontal read line resistance RH and the horizontal read line capacitance CH can be made uniform for each line.

FIG. 4 shows the horizontal read line 3 from the horizontal switch 5 of the solid-state image sensor according to the third embodiment of the present invention.
The structure of the part up to is shown. The structure of FIG. 4 is the same as that of FIG. 3, but in the embodiment of FIG. 4, a third layer aluminum 39 is further used for light shielding.

Therefore, the solid-state image pickup device shown in FIG. 4 can be used not only for an electronic still camera with a mechanical shutter, but also for an electronic shutter still camera or a moving image pickup.

FIG. 5 shows the horizontal read line 3 from the horizontal switch 5 of the solid-state image sensor according to the fourth embodiment of the present invention.
The structure of the part up to is shown. The circuit pattern of the solid-state image sensor according to this embodiment is the same as that shown in FIG. 3, but the black filter 41 is used to shield light. Generally, a solid-state image sensor is often used as a color image sensor. Therefore, color filters of R, G, and B colors and a black filter for preventing color mixture are provided on the element.
In this embodiment, the black filter 41 is used to shield light. Not only the black filter 41 but also R, G, B3
If the color filters are also overlapped, more reliable light shielding can be performed.

Therefore, the solid-state image pickup device according to the embodiment shown in FIG. 5 can be used not only for the electronic still camera with the mechanical shutter but also for the electronic shutter still camera and moving image pickup, as in the case of FIG. Can be used. Also,
In this embodiment, a solid-state image sensor with light shielding can be realized without adding a special manufacturing process.

FIG. 6 shows a horizontal read line 3 from the horizontal switch 5 of the solid-state image pickup device according to the fifth embodiment of the present invention.
The structure around the part up to is shown. The structure shown in FIG.
The bridging wiring 37a in the portion from the drain 6 of the horizontal switch 5 to the vertical signal line 15b is formed of polycrystalline silicon. The capacity of this bridging wiring 37a is
Since it works as a part of the storage capacitor 7, there is no loss of signal charge. Here, in order to eliminate the variation in the size of the output for each line due to the wiring resistance of the polycrystalline silicon, the transistor (QHD) of the bottom horizontal switch 5 that does not originally need to be bridged has the same dummy as the bridged wire. A pattern is provided, and the bridging wiring 37a has the same length with respect to the four vertical signal lines 15b. The dummy pattern portion of the bridging wiring 37a is meandering in order to realize the same wiring length in a small area.

In the structure of FIG. 6, since the bridging wiring 37a is made of polycrystalline silicon, it is possible to shield light by using the second layer aluminum. Reference numeral 43 indicates a light-shielding aluminum formed by using such a second layer aluminum.

In the embodiments shown in FIGS. 3 to 6, the signal wiring from the horizontal switch 5 to the horizontal read line 3 can be made extremely short, and the horizontal read line resistance RH and the horizontal read line capacitance CH are also greatly increased. The signal output loss and the signal delay can be reduced. Also, the horizontal read resistance RH for each horizontal line
Also, the horizontal read line capacity can be made uniform, the variation in the output size for each line can be reduced, and the fixed pattern noise removal effect can be greatly enhanced.

[0051]

As described above, according to the present invention, the bridging portion between the horizontal switch 5 and the horizontal read line 3 is connected using aluminum wiring, or the horizontal switch 5 and the horizontal read line 3 are connected. Since it can be directly connected with aluminum wiring without bridging, the capacitance and resistance related to the horizontal read line can be made extremely small, and the output signal delay and signal loss due to charge distribution of the capacitance can be greatly reduced. Therefore, the sensitivity of the image sensor can be significantly increased.

Further, it is possible to make the size of the capacitance and resistance of each horizontal read line uniform, and it is possible to reduce the variation of the output size of each horizontal line.
Therefore, in order to cancel fixed pattern noise (Vsi
It is possible to significantly reduce the effect of canceling fixed pattern noise by reducing the calculation error during the subtraction of (g-Vdark). Further, in an element provided with horizontal read lines of a plurality of channels, it is possible to prevent the occurrence of an output level difference for each channel.

[Brief description of drawings]

FIG. 1 is an enlarged plan view showing a pattern structure near a horizontal switch of a solid-state image sensor according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a cross-sectional structure along the line AA in FIG.

FIG. 3 is an enlarged plan view showing a pattern structure in the vicinity of a horizontal switch of a solid-state image sensor according to a second embodiment of the present invention.

FIG. 4 is an enlarged plan view showing a pattern structure near a horizontal switch of a solid-state image sensor according to a third embodiment of the present invention.

FIG. 5 is an enlarged plan view showing a pattern structure near a horizontal switch of a solid-state image sensor according to a fourth embodiment of the present invention.

FIG. 6 is an enlarged plan view showing a pattern structure near a horizontal switch of a solid-state image sensor according to a fifth embodiment of the present invention.

FIG. 7 is a partial electric circuit diagram showing a circuit configuration in the vicinity of a horizontal switch of the amplification type solid-state imaging device.

FIG. 8 is an enlarged plan view showing a pattern structure near a horizontal switch of a conventional solid-state imaging device.

9 is a partial cross-sectional view showing a cross-sectional structure along the line AA in FIG.

FIG. 10 is an M constituting a horizontal switch used in a conventional solid-state image sensor and a solid-state image sensor according to the present invention.
FIG. 3 is an enlarged plan view showing the structure of an OS transistor.

[Explanation of symbols]

 1 Pixel Matrix 3 Horizontal Readout Line 5 Horizontal Switch 7 Storage Capacitance 9 Signal Transfer Switch 11 Horizontal Shift Register 12 Output Amplifier 13 Vertical Signal Lines 15, 15a, 15b Vertical Signal Lines 17, 17a, 17b Vertical Connection Lines 19, 19a Bridging Wiring 20 Through Hole 21 Insulating Layer 23 Light Shielding Aluminum (Second Layer Aluminum) 25 Semiconductor Substrate 27 Drain 29 Source 31, 33 Contact Hole 35 Gate Wiring 37, 37a Bridging Wiring 39 Light Shielding Layer (Third Layer Aluminum) 41 Light Shielding Layer (Black Filter) ) 43 Light-shielding layer (second aluminum layer)

Claims (13)

[Claims] 1. A plurality of vertical signal lines for sequentially outputting signals from a plurality of amplification type pixels for accumulating and amplifying signal charges corresponding to respective optical signals for each row, and signals from the respective vertical signal lines in order. A horizontal read element for selecting and outputting, and a horizontal switch element connected between the vertical signal line and the horizontal read line and sequentially coupling the signals from the vertical signal line to the horizontal read line for each column. And an amplification type solid-state imaging device, characterized in that the bridge portion between the horizontal switching device and the horizontal readout line is connected using aluminum wiring. 2. At least the light-shielding aluminum in the vicinity of a bridging portion extending from the horizontal switch element to the horizontal read line is eliminated, and an aluminum layer forming the light-shielded aluminum is used to provide a space between the horizontal switch element and the horizontal read line. The amplification type solid-state imaging device according to claim 1, wherein the bridging portion is connected. 3. The vertical signal line and the horizontal read line are formed by a first layer aluminum, and a bridge portion between the horizontal switch element and the horizontal read line is connected by using a second layer aluminum. The amplification type solid-state imaging device according to claim 1 or 2, characterized in that. 4. A plurality of vertical signal lines that sequentially output signals from a plurality of amplification type pixels that store and amplify signal charges corresponding to respective optical signals for each row, and pixel darkness from each of the vertical signal lines. At least one set of horizontal read lines for dark signal and read signal for sequentially outputting the signal and read signal, and two sets for each vertical signal line for accumulating dark signal charge and read signal charge, respectively. A storage capacitor, a transfer switch element for selectively connecting each vertical signal line to the dark signal storage capacitor or the read signal storage capacitor, and the dark signal storage capacitor and the read signal storage capacitor in each column are respectively darkened. A horizontal switch element for sequentially coupling to horizontal read lines for signals and read signals, the vertical signal line and the horizontal read line being a first
An amplification type solid-state image pickup device, characterized in that it is formed of a second layer of aluminum, and the bridging portion between the horizontal switch element and the horizontal read line is connected by a second layer of aluminum. 5. The amplification type pixel has 2 rows and 2 columns.
The amplification type solid-state imaging device according to claim 4, wherein the amplification type solid-state imaging device is arranged in a dimension. 6. The second layer of aluminum is used to shield light from a desired area other than a bridge portion between the horizontal switch element and the horizontal read line.
5. The amplification type solid-state image pickup device according to any one of items 1 to 5. 7. A plurality of vertical signal lines for sequentially outputting signals from a plurality of amplification type pixels for accumulating and amplifying signal charges corresponding to respective optical signals for each row, and signals from the respective vertical signal lines in order. A horizontal read element for selecting and outputting, and a horizontal switch element connected between the vertical signal line and the horizontal read line and sequentially coupling the signals from the vertical signal line to the horizontal read line for each column. And the horizontal read line and the horizontal switch element are alternately arranged, and the horizontal switch element connected to the horizontal read line is adjacent to the horizontal read line, thereby providing the horizontal read line and the horizontal switch element. An amplification type solid-state imaging device, characterized in that the wiring connecting to and is shortened. 8. The vertical signal line and the horizontal read line are formed of a first layer aluminum, and the horizontal switch element corresponding to the horizontal read line is also connected by the first layer aluminum. 7. The amplification type solid-state imaging device according to 7. 9. The amplification type solid-state imaging device according to claim 8, wherein the horizontal switching device and the corresponding vertical signal line are connected by a second layer aluminum. 10. The amplification type solid-state imaging device according to claim 9, wherein the second layer aluminum is used to shield light from a desired area other than a connection portion between the horizontal switch element and the vertical signal line. element. 11. The horizontal switching element and the corresponding vertical signal line are connected by a polycrystalline silicon layer, and the horizontal switching element portion is shielded from light by a second layer aluminum. 8. The amplification type solid-state imaging device according to item 8. 12. The amplification type solid-state imaging device according to claim 1, wherein at least the horizontal switch element portion is shielded from light by using a third layer aluminum. 13. The amplification type solid-state imaging device according to claim 1, wherein at least the horizontal switch element portion is shielded by using a black filter.