JP6708698B2 - Photoelectric conversion device and imaging system using the photoelectric conversion device - Google Patents

Description

The present invention relates to a stacked photoelectric conversion device.

In recent years, a CMOS-type photoelectric conversion device in which a plurality of substrates (so-called chips) are stacked has been studied for miniaturization and improvement of characteristics.

Patent Document 1 discloses that in a stacked photoelectric conversion device, a first chip is provided with a circuit that requires pixels and analog characteristics and noise characteristics, and a second chip is provided with a circuit that operates at high speed with a low voltage. Has been done.

JP, 2011-159958, A

The inventors of the present invention have found that in the configuration of Patent Document 1, heat is generated in each circuit, so that noise increases and image quality deteriorates. This is to increase the dark noise in the photoelectric conversion region provided so that the heat of the circuits overlaps.

Therefore, an object of the present invention is to provide a stacked photoelectric conversion device with reduced noise.

A photoelectric conversion device of the present invention includes a first substrate including a photoelectric conversion region and a peripheral region, and a circuit that processes a signal from the photoelectric conversion region, overlaps with the first substrate, and includes the photoelectric conversion region and the photoelectric conversion region. In a photoelectric conversion device including a second substrate having a main surface including an orthogonal projection of a peripheral region, a circuit that processes a signal from the photoelectric conversion region includes a first circuit and a driving frequency higher than that of the first circuit. The second circuit is provided only in a region of the orthogonal projection of the peripheral region on the main surface of the second substrate.

The photoelectric conversion device of the present invention makes it possible to provide a stacked photoelectric conversion device in which noise is reduced.

(A) Block diagram for explaining the entire photoelectric conversion device of the first embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the first embodiment, (c) First embodiment FIG. 3 is a block diagram for explaining the second substrate of the photoelectric conversion device of the embodiment, and (d) a schematic cross-sectional view for explaining the entire photoelectric conversion device of the first embodiment. (A) Block diagram for explaining the whole photoelectric conversion device of the second embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the second embodiment, (c) Second embodiment. It is a block diagram for explaining the 2nd substrate of the photoelectric conversion device of the form. (A) Block diagram for explaining the whole photoelectric conversion device of the third embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the third embodiment, (c) Third embodiment. It is a block diagram for explaining the 2nd substrate of the photoelectric conversion device of the form. (A) Block diagram for explaining the whole photoelectric conversion device of the fourth embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the fourth embodiment, (c) Fourth embodiment. It is a block diagram for explaining the 2nd substrate of the photoelectric conversion device of the form. (A) Block diagram for explaining the whole photoelectric conversion device of the fifth embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the fifth embodiment, (c) Fifth embodiment. It is a block diagram for explaining the 2nd substrate of the photoelectric conversion device of the form. (A) Block diagram for explaining the whole photoelectric conversion device of the sixth embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the sixth embodiment, (c) Sixth embodiment. Block diagram for explaining the second substrate of the photoelectric conversion device of the embodiment, (d) a block diagram for explaining the third substrate of the photoelectric conversion device of the sixth embodiment, (e) photoelectric conversion of the sixth embodiment It is a cross-sectional schematic diagram for demonstrating the whole apparatus. (A) Block diagram for explaining the whole photoelectric conversion device of the seventh embodiment, (b) Block diagram for explaining the first substrate of the photoelectric conversion device of the seventh embodiment, (c) Seventh embodiment. It is a block diagram for demonstrating the 2nd board|substrate of the photoelectric conversion apparatus of the form, (d) Block diagram for demonstrating the 3rd board|substrate of the photoelectric conversion apparatus of 7th Embodiment.

The photoelectric conversion device of the present invention includes a first substrate and a second substrate. The first substrate includes a photoelectric conversion region and a peripheral region. The second substrate includes a circuit that processes a signal from the photoelectric conversion region and overlaps the first substrate. Here, on the main surface of the second substrate, a circuit that processes a signal from the photoelectric conversion region including the orthogonal projection of the photoelectric conversion region and the peripheral region is a first circuit and a second circuit having a driving frequency higher than that of the first circuit. And circuit. The second circuit is provided in the area of the orthogonal projection of the peripheral area.

With such a configuration, since a circuit serving as a heat source is provided outside the photoelectric conversion region, it is possible to suppress an increase in noise.

In addition, if the arrangement of the circuits that generate heat is uneven in the plane of the photoelectric conversion region, large unevenness may occur in the image. This is because the heat distribution occurs in the plane of the photoelectric conversion region, and the dark noise has a distribution. On the other hand, by providing the circuit uniformly in the photoelectric conversion region, it is possible to reduce the unevenness of noise.

The photoelectric conversion region is a region in which a plurality of pixels including photoelectric conversion elements are provided, and the photoelectric conversion region can also be referred to as an imaging region. The signal of the photoelectric conversion region may be used for focus detection and light amount detection as well as imaging. For example, in a CMOS photoelectric conversion device, it is a region where pixels including photodiodes, which are photoelectric conversion elements, and pixel cells including a plurality of photoelectric conversion elements are arranged. For example, a current source provided for each column and a pixel drive circuit provided for each row are not included in the photoelectric conversion region.

The peripheral region is a region other than the photoelectric conversion region of the first substrate on which the photoelectric conversion region is provided. A circuit that processes a signal from the photoelectric conversion region may be provided in this peripheral region, similarly to the second substrate.

The first substrate and the second substrate each include a semiconductor substrate, a wiring layer, and an insulating film. The surface on the wiring layer side of the substrate is the front surface, and the opposite side is the back surface. The main surface of the substrate is the surface of the semiconductor substrate on which the element is provided, for example, the interface with the gate insulating film of the MOS transistor. In the following embodiments, it is assumed that the orthogonal projection is performed on the main surface of the second substrate, and the provision of the circuit on the area where the circuit overlaps the area where the circuit exists indicates the orthogonal projection on the main surface of the second substrate. It means that the circuit in the area is provided. Alternatively, it indicates that the orthogonal projection of the circuit and the area on the main surface of the second substrate overlaps. In addition, the element formation range on the surface of the semiconductor substrate on which the elements are provided, that is, the main surface is regarded as the range where the circuit is formed. In addition, in the following embodiments, it is assumed that the first substrate and the second substrate are overlapped so that the surface of the first substrate and the surface of the second substrate face each other. However, the first substrate and the second substrate may be overlapped so that any surfaces face each other.

Hereinafter, a specific description will be given with reference to the drawings.

(First embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. First, the entire photoelectric conversion device of this embodiment will be described with reference to FIG.

FIG. 1A is a block diagram for explaining the entire photoelectric conversion device. The photoelectric conversion device has a photoelectric conversion region 103. A plurality of pixels including photoelectric conversion elements are arranged in the photoelectric conversion region 103, and photoelectric conversion for imaging is performed. In the photoelectric conversion area 103, column signal lines for outputting signals from each pixel are arranged. That is, the photoelectric conversion region is a region including pixels and column signal lines. In addition, each pixel includes a transfer transistor, a reset transistor, and a source follower transistor that configures a source follower circuit in the present embodiment, but the configuration is arbitrary.

The photoelectric conversion device further includes a column circuit 104, a comparison circuit 105, a reference power supply circuit 106, a counter circuit 107, a timing generator circuit (hereinafter, TG circuit) 108, a signal holding circuit 109, a horizontal scanning circuit 110, a vertical scanning circuit 111, The pixel drive circuit 112 is included. The column circuit 104 is provided for each column signal line and includes a current source forming a source follower circuit. In addition, the column circuit 104 may have an amplification unit provided for each column. The comparison circuit 105, the reference power supply circuit 106, the counter circuit 107, and the signal holding circuit 109 can convert a signal from the photoelectric conversion region 103 which is an analog signal into a digital signal. That is, they can function as analog-to-digital converters. The comparison circuit 105 is also referred to as a comparator. The reference power supply circuit can supply a reference voltage having a ramp (RAMP) waveform, but the reference power supply circuit may include a digital-analog converter (DAC). The TG circuit 108 generates control signals for controlling the operations of the vertical scanning circuit 111, the column circuit 104, the reference power supply circuit 106, the horizontal scanning circuit 110, and the like. The pixel drive circuit 112 is a circuit that generates a signal for driving a transistor of a pixel based on a signal from the vertical scanning circuit 111. The horizontal scanning circuit 110 controls an operation of sequentially reading out signals based on a plurality of signal lines (here, column signal lines) processed in parallel to a common signal line. In this embodiment, the signal holding circuit 109 includes a common signal line. Further, the signal holding circuit 109 includes a plurality of signal holding elements such as so-called memories. The signal holding circuit 109 may include an addition element. A circuit that processes a signal from the photoelectric conversion region is a circuit that amplifies and converts a signal and includes a column circuit 104, a comparison circuit 105, a signal holding circuit 109, an analog-digital converter, and the like.

The photoelectric conversion device of this embodiment has the image signal processing unit 113. The image signal processing unit 113 has an image signal processing circuit 114, a microprocessor 115, and a signal holding circuit 116. Like the signal holding circuit 109, the signal holding circuit 116 includes a plurality of memories, so-called signal holding elements. Further, the photoelectric conversion device has an input interface (hereinafter, input IF) 117 and an output interface (hereinafter, output IF) 118.

In the photoelectric conversion device of this embodiment, each component is provided on two substrates.

FIG. 1D schematically shows a cross section of two substrates of the photoelectric conversion device of this embodiment. A first substrate 101 having a front surface 120 and a back surface 190 and a second substrate 102 having a front surface 121 and a back surface 122 are stacked. The structure of FIG. 1D is obtained by joining or adhering the two substrates so that the surface 120 of the first substrate 101 and the surface 121 of the second substrate 102 face each other. These two substrates can be electrically connected by through electrodes or bumps. The photoelectric conversion device of this embodiment is a so-called backside illumination type photoelectric conversion device in which light 123 is incident on the backside 119 side of the first substrate 101.

FIG. 1B and FIG. 1C are block diagrams for explaining the first substrate and the second substrate. FIG. 1B and FIG. 1C are schematic diagrams when the configuration of each substrate is projected on the main surface of the second substrate, and can be said to be a so-called planar layout of each substrate. Here, it is assumed that the projection is performed from the direction indicated by the light 123 shown in FIG.

As shown in FIG. 1B, the first substrate 101 is provided with a photoelectric conversion region 103 and a current source 104a that is a part of the column circuit 104. The current source 104a is provided in the peripheral region 129 which is a region other than the photoelectric conversion region 103. The peripheral region 129 has a first portion 129a and a second portion 129b that sandwich the photoelectric conversion region 103. The two current sources 104a are provided so as to sandwich the photoelectric conversion region 103. In other words, the current source 104a is provided on each of the two sides in the X-axis direction of the rectangular photoelectric conversion region 103 having the sides in the X-axis direction and the sides in the Y-axis direction. At this time, the two current sources 104a are preferably equivalent circuits in order to enhance the symmetry.

As shown in FIG. 1C, the second substrate 102 is provided with a configuration other than the photoelectric conversion region 103 and the current source 104a. Specifically, the amplification unit 104b that is a part of the column circuit 104, the comparison circuit 105, the reference power supply circuit 106, the counter circuit 107, the TG circuit 108, the signal holding circuit 109, the horizontal scanning circuit 110, the vertical scanning circuit 111, and the pixel. The drive circuit 112. The second board 102 is also provided with an input IF 117 and an output IF 118. A region 130 that overlaps with the photoelectric conversion region 103 when the first substrate 101 and the second substrate 102 are stacked includes the first circuit driven by the first clock. The first circuit includes an amplification unit 104b, a comparison circuit 105, a TG circuit 108, a vertical scanning circuit 111, and a pixel drive circuit 112. These circuits overlap the photoelectric conversion region 103. In other words, the first circuit is provided in the region of the orthogonal projection of the photoelectric conversion region 103 on the main surface of the second substrate 102. The other area 131 includes a second circuit driven by a second clock having a frequency higher than the first clock. That is, the second circuit is driven at a higher drive frequency than the first circuit. The second circuit includes a reference power supply circuit 106, a counter circuit 107, a signal holding circuit 109, a horizontal scanning circuit 110, an image signal processing unit 113, an input IF 117, and an output IF 118. These circuits are not provided in the orthogonal projection region of the photoelectric conversion region 103 on the main surface of the second substrate 102, but are provided only in the orthogonal projection region of the peripheral region 129. In the present embodiment, the second circuit includes the counter circuit 107 and the horizontal scanning circuit 110. With such a structure, it is possible to provide a stacked photoelectric conversion device with reduced noise.

Since the second circuit has a higher driving frequency and higher power consumption than the first circuit, it generates a large amount of heat. Therefore, if such a circuit that serves as a heat source is provided so as to overlap the photoelectric conversion region 103, heat is transferred to the photoelectric conversion region 103 and noise is increased. For example, if a part of the photoelectric conversion area 103 is provided in the orthogonal projection area, heat may be transferred to a part of the photoelectric conversion area 103, which may cause unevenness in the image. Therefore, it is preferable that at least the second circuit of the second substrate 102 is provided only in the region of the orthogonal projection of the peripheral region 129 on the main surface of the second substrate 102.

Here, for example, the first clock is related to the speed of vertical scanning, and the second clock is related to horizontal scanning. For example, the first clock is a signal or a clock for driving a portion where the operation is parallel processing, and the second clock is the signal or the processing when the parallel processing is converted to the serial processing. This is a clock for driving the part that is being operated. Therefore, the first clock has a higher frequency than the second clock. Specifically, the frequency of the second clock is higher than the frequency of the first clock by 100 times or more, for example, about 500 times, or even about 1200 times.

Note that the area of the counter circuit 107 is generally less than or equal to 1/100 of the area of the photoelectric conversion region 103, and it is difficult to arrange the counter circuit 107 uniformly in the photoelectric conversion region 103. When the counter circuit 107 is provided for each column, the current consumption may differ depending on the signal, which may cause heat distribution. Further, the horizontal scanning circuit 110 is, for example, a shift register circuit or a decoder, but these may also have an area that is one-fourth or less of the area of the photoelectric conversion region 103, so that the photoelectric conversion region 103 is evenly distributed. Difficult to place. If they cannot be arranged uniformly, unevenness or streaky noise may occur and the image quality may deteriorate. Therefore, a circuit which is the second circuit and whose orthogonal projection area is half or less of the orthogonal projection area of the photoelectric conversion region is arranged so as to overlap the peripheral region 129 of the first substrate 101. Is more desirable.

In the present embodiment, the peripheral region 129 includes the first portion 129a and the second portion 129b, and the overlapping region 131 also overlaps corresponding to the first portion 129a, the third portion 131a and the second portion 129b. And a fourth portion 131b. Further, the circuits provided in the first portion 129a and the second portion 129b are both current sources 104a and are equivalent circuits. The circuits provided in the third portion 131a and the fourth portion 131b are the reference power supply circuit 106, the counter circuit 107, the signal holding circuit 109, the horizontal scanning circuit 110, the image signal processing unit 113, and the output IF 118, respectively, and are equivalent. It is a circuit. With such a configuration, the symmetry of the signal output path can be improved, and the image quality can be improved.

Further, in this embodiment, the reference power supply circuit 106 is also provided in the region 131. The reference power supply circuit 106 may serve as a heat source even in the case of a DAC or a form having many resistors. In addition, since the reference power supply circuit 106 generally has an area that is one-tenth or less that of the photoelectric conversion region 103, it is difficult to uniformly arrange the reference power supply circuit 106 with respect to the photoelectric conversion region 103. By providing such a circuit in the region 131, noise of the photoelectric conversion device can be further reduced.

Further, in the region 130, the two comparison circuits 105 are provided so as to sandwich the amplifying unit 104b, and the TG circuit 108 and the vertical scanning circuit 111 are provided so as to sandwich the amplifying unit 104b. Since the two comparison circuits 105 are provided, the signals can be output from the two output IFs 118 with good symmetry, and the reading speed can be improved.

Since the image signal processing unit 113 includes the microprocessor 115 and the image signal processing circuit 114 which are driven at a frequency higher than the first clock, it is desirable that the image signal processing unit 113 is provided in the other area 131. However, in the image signal processing unit 113 having a large area, by arranging the circuits so that the heat generation points become uniform in the image signal processing unit 113, the orthogonal projection of the photoelectric conversion region on the main surface of the second substrate is obtained. It can be provided in the area. Alternatively, the image signal processing unit 113 may be provided outside the photoelectric conversion device.

The peripheral region 129 is not limited to the region of this embodiment as long as it is a portion that is not the photoelectric conversion region 103.

(Second embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. 2 is a drawing corresponding to FIG. 1. FIG. 2(a) is shown in FIG. 1(a), FIG. 2(b) is shown in FIG. 1(b), and FIG. 2(c) is shown in FIG. 1(c). Each corresponds. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device according to the present embodiment is different from the photoelectric conversion device according to the first embodiment in the arrangement of circuits in the region 230 overlapping the photoelectric conversion region 103 and the circuits provided in the peripheral region 229 of the first substrate 101.

As shown in FIGS. 2A and 2B, the photoelectric conversion device according to the present embodiment includes a photoelectric conversion region 103 on the first substrate 101, a current source 104 a according to the first embodiment, and an amplification. A column circuit 104 having both parts 104b. That is, the peripheral region 229 of this embodiment includes the column circuit 104. Then, as shown in FIG. 2C, in the region 230 overlapping the photoelectric conversion region 103 of the second substrate 102, the comparison circuit 105, the TG circuit 108, the vertical scanning circuit 111, the pixel drive circuit 112, and the non-circuit portion 224. including. The non-circuit part 224 is a part where no circuit is provided. By disposing such a circuitless portion 224 so as to overlap the photoelectric conversion region 103, it is possible to reduce noise in the photoelectric conversion region 103.

Also in this embodiment, the vertical scanning circuit 111 and the pixel driving circuit 112 are provided corresponding to the sides of the photoelectric conversion region 103 in the Y-axis direction. A signal for driving a pixel is supplied from the side of the photoelectric conversion region 103 in the Y-axis direction. Therefore, with such a configuration, it becomes possible to supply the signal for driving the pixel to the photoelectric conversion region 103 in the shortest distance.

Further, in the regions 220 and 221, two comparison circuits 105, two signal holding circuits 109, and the like are provided in the Y-axis direction (in the vertical direction), so that a signal from the photoelectric conversion region 103 is generated in the Y-axis direction. It is possible to sort and process (up and down). That is, it is possible to improve the read speed as in the first embodiment.

(Third Embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. FIG. 3 is a drawing corresponding to FIGS. 1 and 2. Here, FIG. 3 will be described in comparison with the second embodiment (FIG. 2). 3A corresponds to FIG. 2A, FIG. 3B corresponds to FIG. 2B, and FIG. 3C corresponds to FIG. 2C. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device according to the present embodiment is different from the photoelectric conversion device according to the second embodiment in the arrangement of circuits in a region 330 overlapping the photoelectric conversion region 103. That is, FIGS. 3(a) and 3(b) are the same as FIGS. 2(a) and 2(b), and thus the description thereof will be omitted.

In the photoelectric conversion device of this embodiment, as shown in FIG. 3C, in the region 330 overlapping the photoelectric conversion region 103 of the second substrate 102, there is no comparison circuit 105, the TG circuit 108, the vertical scanning circuit 111, The pixel drive circuit 112 and the non-circuit part 224 are included. That is, the first circuit does not include the comparison circuit 105, but includes the TG circuit 108, the vertical scanning circuit 111, the pixel drive circuit 112, and the non-circuit section 224. With such a configuration, it is possible to reduce noise in the photoelectric conversion device also in this embodiment.

Further, the two regions 331 are provided so as to sandwich the region 330 in the Y-axis direction. Each of the areas 331 has a highly symmetrical circuit arrangement, and the signal from the photoelectric conversion area 103 can be distributed and processed in the Y-axis direction (vertical direction).

Note that the signal holding circuit may have an area equal to that of the photoelectric conversion region 103. In that case, it is preferable to provide the non-circuit part 224.

(Fourth Embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. FIG. 4 is a drawing corresponding to FIGS. 1 to 3. Here, FIG. 4 will be described in comparison with the second embodiment (FIG. 2). FIG. 4A corresponds to FIG. 2A, FIG. 4B corresponds to FIG. 2B, and FIG. 4C corresponds to FIG. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device of the present embodiment is different from the photoelectric conversion device of the second embodiment in the arrangement of circuits in a region 430 overlapping the photoelectric conversion region 103 and the circuits provided in the peripheral region 429 of the first substrate 101.

In the photoelectric conversion device of this embodiment, as shown in FIGS. 4A and 4B, the first substrate 101 has a photoelectric conversion region 103, a column circuit 104, a vertical scanning circuit 111, and a pixel driving circuit. 112 is included. That is, the peripheral region 229 of the present embodiment includes the column circuit 104, the vertical scanning circuit 111, and the pixel driving circuit 112. Then, as shown in FIG. 4C, only the comparison circuit 105 and the TG circuit 108 are arranged in a region 430 overlapping the photoelectric conversion region 103 of the second substrate 102. That is, the first circuit includes the comparison circuit 105 and the TG circuit 108. With such a configuration, it is possible to reduce noise in the photoelectric conversion device also in this embodiment.

Further, in the present embodiment, the number of output IFs 118 is one, and it is possible to reduce the number of terminals.

(Fifth Embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. FIG. 5 is a drawing corresponding to FIGS. 1 to 4. Here, FIG. 5 will be described in comparison with the fourth embodiment (FIG. 4). 5A corresponds to FIG. 4A, FIG. 5B corresponds to FIG. 4B, and FIG. 5C corresponds to FIG. 4C. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device of the present embodiment is different from the photoelectric conversion device of the fourth embodiment in the arrangement of circuits in a region 530 overlapping the photoelectric conversion region 103 and the circuits provided in the peripheral region 529 of the first substrate 101.

In the photoelectric conversion device of this embodiment, as shown in FIGS. 5A and 5B, the first substrate 101 includes a photoelectric conversion region 103, a vertical scanning circuit 111, and a pixel driving circuit 112. .. The peripheral region 229 of the present embodiment includes the vertical scanning circuit 111 and the pixel driving circuit 112. That is, it differs from the fourth embodiment in that the column circuit 104 is not provided on the first substrate 101. Then, as shown in FIG. 5C, a column circuit 104, a comparison circuit 105, and a TG circuit 108 are arranged in a region 530 overlapping the photoelectric conversion region 103 of the second substrate 102. That is, the first circuit includes the column circuit 104, the comparison circuit 105, and the TG circuit 108. With such a configuration, it is possible to reduce noise in the photoelectric conversion device also in this embodiment.

(Sixth Embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. Here, FIG. 6 will be described in comparison with the first embodiment (FIG. 1). 6(a) is shown in FIG. 1(a), FIG. 6(b) is shown in FIG. 1(b), FIG. 6(c) is shown in FIG. 1(c), and FIG. 6(e) is shown in FIG. 1(e). It corresponds to each. FIG. 6D is a block diagram illustrating a third substrate newly provided in this embodiment. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device of this embodiment is significantly different from the photoelectric conversion device of the first embodiment in that it has a third substrate 603.

As shown in FIG. 6A, the image signal processing unit 113 and the output IF 118 are provided on the third substrate 603 of this embodiment. The third substrate 603 is arranged so as to overlap the first substrate 101 and the second substrate 102. As shown in FIG. 6E, the surface 626 of the third substrate 603 having the front surface 626 and the back surface 627 is provided so as to be in contact with the back surface 122 of the second substrate 102.

In such a photoelectric conversion device, only the photoelectric conversion region 103 is provided in the first substrate 101, and a circuit or the like is not provided in the peripheral region 629. The second substrate 102 includes a column circuit 104, a comparison circuit 105, a TG circuit 108, a vertical scanning circuit 111, a pixel driving circuit 112, a reference power supply circuit 106, a counter circuit 107, a signal holding circuit 109, a horizontal scanning circuit 110, and an input IF 117. Including. Here, the column circuit 104, the comparison circuit 105, the TG circuit 108, the vertical scanning circuit 111, and the pixel driving circuit 112 which are included in the first circuit are provided in the region 630 which overlaps with the photoelectric conversion region 103. The other region 631 including the second circuit overlaps the peripheral region 629. An image signal processing unit 113 and an output IF 118 are provided on the third substrate 603. Here, the image signal processing unit 113 often includes a microprocessor 115 and an image signal processing circuit 114 that process a signal in synchronization with a clock having a frequency higher than the second clock. However, the influence of heat is small because the second substrate 102 is interposed between the first substrate 101 provided with the photoelectric conversion region 103. Therefore, the photoelectric conversion region 103 and the image signal processing unit 113 may be arranged so as to overlap each other. With such a configuration, it is possible to reduce noise in the photoelectric conversion device also in this embodiment.

(Seventh embodiment)
The photoelectric conversion device of this embodiment will be described with reference to FIG. 7. Here, FIG. 7 will be described in comparison with the sixth embodiment (FIG. 6). FIG. 7A is FIG. 6A, FIG. 7B is FIG. 6B, FIG. 7C is FIG. 6C, and FIG. 7D is FIG. 6D. It corresponds to each. The same components are designated by the same reference numerals and description thereof will be omitted. The photoelectric conversion device of the present embodiment is different from the photoelectric conversion device of the sixth embodiment in the circuit provided on the first substrate 101 and the circuit in the region 730 overlapping the photoelectric conversion region 103. The third substrate 603 of the photoelectric conversion device of this embodiment is the same as that of the sixth embodiment, and thus the description is omitted.

As shown in FIGS. 7A and 7B, a photoelectric conversion region 103 and a column circuit 104 are provided on the first substrate 101 of this embodiment. That is, the column circuit 104 is provided in the peripheral region 729. The area 730 of the second substrate 102 is a non-circuit portion 724 in which no circuit is arranged. Even with such a configuration, it is possible to reduce noise in the photoelectric conversion device.

As an application example of the photoelectric conversion device described above, an image pickup system incorporating the photoelectric conversion device will be exemplarily described. The concept of the imaging system includes not only a device whose main purpose is shooting (for example, a still camera or a camcorder) but also a device which additionally has a shooting function (for example, a personal computer or a mobile terminal). The imaging system includes the photoelectric conversion device according to the present invention exemplified as the above embodiment, and a processing unit that processes a signal output from the photoelectric conversion device. Alternatively, it has an optical system (for example, a lens) for forming an image on the photoelectric conversion device according to the present invention.

As described in the above embodiments, according to the photoelectric conversion device of the present invention, noise can be reduced and a high quality image can be obtained.

The photoelectric conversion device of the present invention is not limited to the above embodiment. For example, the respective embodiments can be appropriately modified and combined.

101 First Substrate 102 Second Substrate 103 Photoelectric Conversion Area 104 Column Circuit (Current Source + Column Amplifier)
106 reference power supply circuit 107 counter circuit 108 timing generation circuit 109 signal holding circuit 110 horizontal scanning circuit 111 vertical scanning circuit

Claims (11)

A photoelectric conversion device,
A first substrate including a photoelectric conversion region in which a plurality of pixels each having a photoelectric conversion element are two-dimensionally arranged;
A second substrate having a pixel drive circuit for generating a signal for driving a transistor of the pixel;
A third substrate that includes a memory and a microprocessor and that has an image signal processing unit that processes a signal output from the photoelectric conversion element ;
The photoelectric conversion device, wherein the first substrate, the second substrate, and the third substrate are laminated in this order . A photoelectric conversion device,
A first substrate including a photoelectric conversion region in which a plurality of pixels each having a photoelectric conversion element are two-dimensionally arranged;
A second substrate having a pixel drive circuit that generates a signal for driving the transistor of the pixel and a comparison circuit of an analog-digital conversion unit;
A third substrate having an image signal processing unit that processes a signal output from the photoelectric conversion element,
The photoelectric conversion device, wherein the first substrate, the second substrate, and the third substrate are laminated in this order. And the photoelectric conversion region, the image signal processing unit, the photoelectric conversion device according to claim 1 or 2, characterized in that overlap in plan view. The photoelectric conversion region, the pixel driving circuit, the photoelectric conversion device according to any one of claims 1 to 3, characterized in that overlap in plan view. The photoelectric conversion device according to claim 2 , wherein the photoelectric conversion region and the comparison circuit of the analog-digital conversion unit overlap in a plan view. The photoelectric conversion device according to claim 1, further comprising an output interface on the third substrate. The photoelectric conversion device according to any one of claims 1 to 6, wherein the second substrate has an input interface. A timing generator circuit on the second substrate,
The photoelectric conversion device according to any one of claims 1 to 7, wherein the photoelectric conversion region and the timing generator circuit overlap each other in a plan view. The photoelectric conversion according to any one of claims 1 to 8, wherein the second substrate has a non-circuit section not provided with a circuit, and the photoelectric conversion region and the non-circuit section overlap each other in plan view. apparatus. The photoelectric conversion device according to claim 1, wherein the second substrate includes a signal holding circuit. A photoelectric conversion device according to any one of claims 1 to 10 ,
An image pickup system comprising: a processing circuit that processes a signal from the photoelectric conversion device.