JP3071161B2 - Photoelectric converter, image processing device, and photoelectric conversion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric converter and an image processing apparatus.
Related to optical devices and photoelectric conversion devices.
Converter with light-receiving part, light-receiving part, light-shielding part, signal processing
Processing unit having a memory unit, memory unit, light receiving unit, light shielding unit
Photoelectric conversion device equipped with multiple line sensors
Related .

[0002]

BACKGROUND ART facsimile, one photoelectric converter for use in an image reading apparatus used in a copying machine or the like, charges generated by light irradiation to accumulate, retrieve the amplified output corresponding to the accumulated charge there are photoelectric converter.

[0003] Such a single photoelectric converter, the base region of the phototransistor is irradiated with light, to accumulate carriers (holes), there is a photoelectric converter for taking out a current amplified from the emitter region. In this case, the base region of the phototransistor is formed in the light receiving portion, and the emitter region is formed in the light shielding portion. Photoelectric converter using the phototransistor, a photodiode, compared with having no photoelectric converter function of amplifying the photocurrent, it is possible to amplify a carrier of the light-receiving portion, to improve the sensitivity, reducing the random noise As a result, the S / N ratio can be improved.

[0004] Figure 15 is a schematic sectional view showing a conventional photoelectric converter. 10, reference numeral 1013 denotes an n-type layer, which is a collector of a phototransistor; 1003, an n ^- epitaxial layer; 1005, a p-layer, which is a base region of the phototransistor; 1006, an n-layer which is an emitter region of the phototransistor; Is an emitter electrode made of Al or the like, and 8 is a LOCOS oxide film. L indicates a light receiving unit, and D indicates a light shielding unit.

When such a photoelectric converter is used as a color line sensor 1101 as shown in FIG. 16, three line sensors for red (R), green (G) and blue (B) are provided. The line sensor includes a light shielding unit 1011 and a light receiving unit 1012. The lengths of the light shielding unit 1011 and the light receiving unit 1012 in the line sensor array direction (direction A in the drawing) are n bits and 1 bit, respectively (that is, the light shielding unit 1012).
Has a width that is an integral multiple of the width of the light receiving section. ) . One bit corresponds to the light receiving part of one photosensor cell, for example, one side is 10
the square shape of μm.

As described above, since each line sensor corresponding to RGB is different in position, when the R signal of a certain line of the document is obtained, the G signal is (n +
2) The original position of the line and the B signal are signals of the original position of the (2n + 3) th line. Therefore, in order to obtain the RGB signals at the same document position, the RGB signals output at least first through the sample hold circuit (S / H) 1014 and the A / D conversion circuit 1015 are stored in the external memory 1102. There is a need to.

[0007] Such a photoelectric converter is disclosed in, for example, European Patent Publication No. 0132076. FIG. 17 (A) is a schematic plan view for explaining a configuration example of a photoelectric converter and more specifically, FIG. 17 (B)
17A is taken along the line AA 'shown in FIG.
FIG. 4 is a schematic cross-sectional view of a case in which is cut.

In each figure, photoelectric conversion cells are arranged on an n silicon substrate 3201, and each cell is made of SiO ₂ ,
It is electrically insulated from adjacent cells by an element isolation region 3202 made of Si ₃ N ₄ or polysilicon or the like. Each cell has the following configuration.

A p-type impurity (for example, boron) is doped on n ⁻ region 3203 having a low impurity concentration formed by an epitaxial technique or the like, so that p − base region 3203 is formed.
204 and p region 3205 are formed, and n ⁺ emitter region 3206 is formed in p base region 3204.

[0010] The p base region 3204 and the p region 3205 also serve as the source and drain of a p-channel MOS transistor described later. An oxide film 3207 is formed on n ⁻ region 3203 where each region is formed as described above, and a gate electrode 3208 of the MOS transistor and a capacitor electrode 3209 are formed on oxide film 3207. Capacitor electrode 3209 faces p base region 3204 with oxide film 3207 interposed therebetween, and forms a capacitor for controlling the base potential.

In addition, an emitter electrode 3210 connected to the n ⁺ emitter region 3206, an electrode 3211 connected to the p region 3205, and a collector electrode 3212 are formed on the back surface of the substrate 3201 with an ohmic contact layer interposed therebetween. Next, the operation of the photoelectric conversion cell will be described.

Light enters from the p base region 3204 side,
Carriers (here, holes) corresponding to the light amount are accumulated in the p base region 3204 (accumulation operation). The base potential changes depending on the accumulated carriers, and by reading the change in the potential from the emitter electrode 3210, an electric signal corresponding to the amount of incident light can be obtained (read operation).

Next, a refresh operation for removing holes accumulated in p base region 3204 will be described.
FIGS. 18A and 18B are voltage waveform diagrams for explaining the refresh operation, respectively.

As shown in FIG. 18A, the MOS transistor is turned on only when a negative voltage higher than the threshold value is applied to gate electrode 3208. Also, FIG.
As shown in (B), to perform the refresh operation, the emitter electrode 3210 is grounded and the electrode 3211 is kept at the ground potential. Then, first, a negative voltage is applied to the gate electrode 3208 to turn on the p-channel MOS transistor. Thereby, the p base region 3
The potential of 204 has a constant value regardless of the level of the accumulated potential. Subsequently, by applying a refresh positive voltage pulse to the capacitor electrode 3209, the p base region 3204
Is forward biased with respect to the n ⁺ emitter region 3206, and the accumulated electrode is grounded to the emitter electrode 32.
Removed through 10. When the refresh pulse falls, p base region 3204 returns to the initial state of negative potential (refresh operation). in this way,
After the potential of the p base region 3204 is set to a constant potential by the MOS transistor, the refresh pulse is applied to erase the residual charges, so that a new storage operation can be performed without depending on the previous storage potential. Also,
Residual charges can be quickly eliminated, and high-speed operation can be performed.

Thereafter, the respective operations of accumulation, readout, and refresh are similarly repeated. Here, the potential V generated in the base by the holes accumulated in the base due to the light excitation
_P is given by V _P = Q / C. Q is the amount of charge of holes accumulated in the base, and C is the capacitance connected to the base. As is apparent from this equation, when highly integrated,
Q also by C becomes both smaller with little shrinkage of cell size, potential V _P which is generated by photoexcitation is kept substantially constant. Therefore, the scheme proposed here is:
This is also advantageous for higher resolution.

[0016]

However, in the above-mentioned photoelectric converter , it may be necessary to further increase the blue sensitivity and to further increase the response of the semiconductor transistor, and it is desired to further improve the characteristics. Was rare.

When image processing is performed using the color line sensor 1101 described with reference to FIGS. 15 and 16, in order to obtain RGB signals at the same original position, the previously output GB signals are stored in an external memory. In order to store the data, the capacity of the external memory is required to be equal to or larger than a certain value.

Furthermore, in the base region of the phototransistor, it is difficult to optimize the size and the impurity concentration of the phototransistor region because the optimum condition is different from the optimum condition for the photoelectric conversion region and the optimum condition for the bipolar transistor. Yes, further improvement was desired.

The present invention provides a photoelectric conversion device which can increase the blue sensitivity even if the sensitivity is even higher and can respond to an input signal at high speed.
The purpose is to provide a vessel . In addition, the present invention aims at optimizing the sensor unit and the switching unit, and more specifically, a photoelectric transistor capable of optimizing the optimum condition in the base region of the phototransistor and the optimum condition as the bipolar transistor. also an object to provide a transducer.

[0020] The present invention also aims to provide a photoelectric conversion device and an image processing apparatus which increases the degree of freedom in system design and optical design can be simplified it like design having a photoelectric converter .

[0021]

The photoelectric converter of the present invention comprises:
A plurality of sets each including a light receiving unit and a light blocking unit, wherein a photoelectric conversion unit is provided in the light receiving unit, and an amplification unit is provided in the light blocking unit to amplify an output from the photoelectric conversion unit; A conversion unit and an input area of the amplification unit are connected through a wiring,
At least one of the light blocking portions is separated by a predetermined distance from the light receiving portion, and at least two of the light receiving portions are adjacent to each other.

The image processing apparatus of the present invention, and a plurality of light receiving elements arranged in a line three light receiving portions including respectively it
A shielding portion provided along the light receiving portion of each for taking out the signal from the light receiving portion of les, a signal processing unit for processing a signal taken from each of the light receiving unit, the signal processing unit A memory unit for storing the signal processed by the
With at least two light-receiving side each other among the three light receiving portions arranged in a line are arranged adjacent to each other, opposite to the side where the light shielding portion according to the light receiving portion is adjacent the light receiving portion Is disposed on the side of

The photoelectric conversion device of the present invention has at least red,
A light-receiving section in which a plurality of light-receiving elements are arranged in a line for reading information corresponding to green and blue, and a light-shielding section provided along a light-receiving section of a line sensor for extracting a signal from the light-receiving element of the light-receiving section. and parts, a line sensor having a plurality, wherein the line sensor is disposed so as the light receiving portion of the other line sensors adjacent to the light receiving portion of the one line sensor among the line sensor is provided adjacent Is what it is.

[0024]

According to the photoelectric converter of the present invention, the photoelectric conversion unit is used as a light receiving unit.
Providing an amplification unit in the light shielding unit, the photoelectric conversion unit and the amplification unit
To the input through a wire, and
Separate one by a predetermined distance from the light receiving unit
And at least two of the light receiving sections are adjacent to each other.
The relationship provides an amplification function and
The light receiving parts are arranged adjacent to each other while separating the light part and the light shielding part.
It is possible to place it. According to the present invention,
Impurities in the semiconductor region that generate and accumulate charge by light incidence
Manufacturing conditions such as material concentration and thickness, and
Impurity concentration of the semiconductor region to be the source region
Fabrication conditions such as cloth and thickness are arbitrarily optimized for each semiconductor region.
It can be optimized.

The image processing apparatus of the present invention is arranged in a line.
At least two of the plurality of light receiving units
Are arranged adjacent to each other, and
Kisaegi light portion and the adjacent side of the light receiving portion is arranged on the opposite side
Output to the destination that should be memorized.
The amount of signal that
Things.

The photoelectric conversion device of the present invention comprises a plurality of line cells.
Adjacent to the light-receiving part of one of the line sensors
Of other line sensors or one line sensor
Light-shielding part of another line sensor adjacent to the light-shielding part of the sensor
Arrange the line sensors so that
This allows the information on the object to be read by the adjacent
To get closer or from the adjacent light shield
This is to extract a signal.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. Figure 1 is a schematic diagram for explaining a first embodiment of a photoelectric converter of the present invention, a schematic plan view of FIG. 1 (A) photoelectric conversion cells, FIG. 1 (B) 1
FIG. 2A is a schematic vertical cross-sectional view taken along line AA ′ of the schematic plan view of FIG.

This photoelectric conversion cell is shown in FIGS. 1A and 1B.
As shown in FIG. 2, an n-type silicon substrate 1 doped with atoms belonging to Group V of the periodic table such as phosphorus (Ph), antimony (Sb), and arsenic (As) as impurities or boron (B), aluminum A silicon substrate 4001 which is made into a p-type by doping an atom belonging to Group III of the periodic table such as (Al) as an impurity, a buried region (n ⁺ ) 4002 formed on the substrate 4001, and a buried region 40
N ⁻ region 4003, n ⁻ region 4003 having a low impurity concentration and formed on epitaxial layer 02 by an epitaxial technique or the like.
A light receiving portion p ⁻ region 4004 doped with an impurity such as boron (B) formed thereon by using impurity diffusion, ion implantation, epitaxial technology, etc., and a bipolar transistor formed using the same technology as the p ⁻ region 4004 p ⁺ region 40 to be the source of the base and the MOS transistor
05, an n ⁺ region 4006 serving as an emitter of a bipolar transistor formed in the p ⁺ region 4005, ap ⁺ region 4007 serving as a drain of a MOS transistor, an n ⁺ region 4008 serving as a channel stop, and a collector resistance of the bipolar transistor. N ⁺ region 40 for lowering
09, an electrode 4101 made of polysilicon or metal serving as a gate of a MOS transistor, an electrode wiring 4108 connected to the electrode 4101, an electrode wiring 4102, 4103 made of polysilicon or metal connected to an emitter of a bipolar transistor. 4104, an electrode wiring 4109 connected to the drain of the MOS transistor, a wiring electrode 4110 connected to the n ⁺ region 4009, an electrode,
Insulating films 4105 and 410 for separating wiring and elements
6,4107. Note that, for simplicity, FIG.
In (A), insulating films 4105, 4106, 410
7 and the electrode wiring 4104 are omitted. Embedding area
The region 4002 is different even on an n-type substrate of the same conductivity type.
On the p-type substrate, which is a conductive type
Good.

[0029] Hereinafter, the operation of the photoelectric converter. FIG. 2A shows FIG. 1B in FIG.
FIG. 2B is a schematic enlarged view showing a cut surface when cut at a portion B ′, and FIG. 2B is a depth direction of FIG.
It is a potential diagram in (left-right direction of (A)).

In FIG. 2A, W is a depletion layer width, x
p, xn are each p ^- region, n ^- region width of the depletion layer, p ^- the depth of the region is shown as xj. In FIG. 2B, W indicates a depletion layer width, and xd indicates a neutral region of ap ⁻ region.
When light is absorbed in the depletion layer (within the width W of the depletion layer), the generated electrons and holes move promptly due to drift, and their recombination does not occur. Therefore, the sensitivity to light is high, but the neutral region (neutral) When light absorption occurs within the region width xd), the generated electrons move by diffusion, and recombine with holes, resulting in low sensitivity to light. Therefore, in the light receiving section, it is better that the neutral region on the surface is small. However, when the surface is depleted, carriers are generated at the interface between the semiconductor and the insulating layer irrespective of the incidence of light, resulting in noise. Therefore, the surface is preferably in a neutral region.

FIG. 3 is a characteristic diagram for explaining the absorption coefficient of Si and Ge with respect to the wavelength of light. As shown in the figure, the shorter the wavelength, the larger the absorption coefficient for both Si and Ge. Now, assuming that Si is a material, the absorption coefficients of blue (λ = 0.45 μm), green (λ = 0.53 μm), and red (λ = 0.65 μm) are respectively blue to 2 × 10 ⁴ cm ^−1. Green to 7.5 × 10 ³ c
m ^-1 , red to 3 × 10 ³ cm ^-1. Considering the half width of the color to be about 0.05 μm, light absorption in Si is blue to
Performed well at a depth of 1 μm, green to 2 μm, red to 5 μm. Therefore, the thickness x of the neutral region on the semiconductor surface
Blue is most affected by d, and the sensitivity is reduced depending on the thickness.

The width of the depletion layer is represented by the following relational expression. 2εs NA + ND W = ───────── (Vbi + VR) (1) q NA · ND kT NA · ND V _bi = {ln} (2) q ni ² ND xp = ─ Ｗ W (3) NA + ND W: depletion layer width, xp: p ⁻ region depletion layer width, NA: p ⁻ region impurity density, ND: n ⁻ region impurity density, εs: dielectric constant, ni: genuine carrier density , VR: reverse bias voltage.

FIG. 4 is a characteristic diagram for explaining the relationship between the p ^- impurity density NA and the total depletion layer width W when the reverse bias voltage VR = 5V. In the figure, the horizontal axis represents the p ⁻ impurity density NA, the vertical axis represents the total depletion layer width W, and the parameter represents the n ⁻ region impurity density ND. For example, in order to efficiently detect all of blue, green, and red, the total depletion layer width is required to be about 5 μm. At this time, ND must be 2 × 10 ¹⁴ cm ⁻³ or less. You can read from the figure.

The spectral sensitivity of the photoelectric converter is approximately expressed by the following equation. λS (λ) = ─────exp (−αxd) 1.24 × (1−exp (−αW)) · T [A / W] (4) λ: wavelength of light, α: absorption of light Coefficient (cm ^-1 ), xd: dead area (neutral area), W: high sensitivity area (depletion layer width),
T: ratio of the amount of light incident on the semiconductor (transmittance).

As can be seen from the above equation (4), since the sensitivity xd is sensitively affected by the thickness, the xd is preferably thin. In addition, sensitivity has wavelength dependence, and blue is
Sensitivity decreases. It is also possible to optimize W by reducing W in order to relatively correct the spectral sensitivity.

As can be seen from FIG. 4 , the width W of the depletion layer can be changed by controlling the concentration of the n ⁻ region. In order to increase the sensitivity of blue, it is better to reduce the neutral region xd. FIG. 5 is a characteristic diagram illustrating the relationship between the p ⁻ impurity density NA and the thickness xp of the p-layer depletion layer.

In the figure, the horizontal axis is p ^- impurity density N
A, the vertical axis indicates the thickness xp of the p-layer depletion layer, and the parameter indicates the n ⁻ region impurity density ND. In the figure, if, for example, ND = 10 ¹⁴ cm ⁻³ and NA in the p region is 10 ¹⁵ cm ⁻³ , xp = 0.6 μm.

If xj of the p region is set to 0.7 μm, the dead region can be set to 0.1 μm, and optimization for increasing blue sensitivity can be performed. The impurity density is increased only in the surface of 0.1 μm, and the impurity density is decreased in the deep region.
A region deeper than 1 μm may be depleted.

In the present invention, the light-receiving surface is neutralized by forming the light-receiving portion into a p ^- region that accumulates charges generated by light incidence and a p ⁺ region that is a base region of the bipolar transistor. The region is kept, and the portion deeper than the vicinity of the surface is depleted, and the thickness of the entire depletion layer can determine the concentration of the n ⁻ region according to the use of spectral sensitivity.

[0040] Figure 6 is a schematic circuit diagram for explaining an embodiment of a drive circuit of a photoelectric converter according to the invention. In this embodiment, a line sensor in which sensors (S1, S3,...) Are arranged in a line will be described.

Each sensor S has a bipolar transistor and a reset transistor Qre connected to its base.
s. Carriers excited by incident light are accumulated at the base of the bipolar transistor and read out to the emitter. When Qres is turned on, it is reset to a constant potential.

The gate electrode of Qres of each sensor S has O
A pulse φres for N / OFF control is input, and Qr
A constant voltage Vbg is applied to the other main electrode of es. A fixed positive voltage is applied to the collector electrode of each sensor S, and the emitter electrodes are connected to the vertical lines L (L1, L2,...).

Each vertical line L has a transistor Qvrs
, And a pulse φres for ON / OFF control is input to the gate electrode of Qvrs. Each vertical line L is connected to a storage capacitor Ct, and a signal is output from the bipolar transistor BPT2 via the transistor Qt.

[0044] Hereinafter, a description will be given of another embodiment of the photoelectric converter of the present invention. Incidentally, the description thereof is omitted are denoted by the same reference numerals for Example the same components shown in FIG. 1 (A) and FIG. 1 (B). FIG. 7 is a schematic sectional view for explaining a second embodiment of the present invention.

As shown in the figure, in this embodiment, the p ⁺ region 4010 and the p ⁺ region 4010 are provided only on the surface of the p ⁻ region 4004 as the light receiving region.
An n region 4011 having a high impurity density is provided below the base of the bipolar transistor to reduce the collector resistance. N ⁻ region 4003 is a low impurity concentration region, n region 4
Reference numeral 011 denotes a high impurity concentration region.
N region 4011 includes p ⁺ region 4005 and n ⁺ region 400
6, between the p ⁺ region 4007 and the buried region 4002.
Have been killed.

FIG. 8 is a schematic sectional view for explaining a third embodiment of the present invention. As shown in the figure, the present embodiment has a structure in which the p ^- region 4004, which is a light receiving region, is extended to the lower portion of the emitter of the bipolar transistor, and the bipolar transistor is made to have a drift base type to measure high speed. That is, a part of the p ⁻ region 4004 is
And n ⁻ region 4003. Needless to say, the bipolar transistor BPT2 on the output side shown in FIG. 6 can also have this structure.

FIG. 9 is a schematic sectional view for explaining a fourth embodiment of the present invention. As shown in the figure, in the present embodiment, the n region 4011 is deepened, and reaches the buried region to lower the collector resistance. p ^- region 4004
Is provided between the p ⁺ region 4005 and the n region 4011
Have been.

FIG. 10 is a schematic sectional view for explaining a fifth embodiment of the present invention. As shown in the drawing, the present embodiment has a structure in which the buried region is limited to only a location such as a bipolar transistor. That is, the n ⁺ region 4002 is
provided except for a region corresponding to the p ^- region 4004.
You.

As shown in the figure, considering the n ⁻ region of the light receiving portion and the p substrate by design, there is no neutral region between the n ⁻ and p substrates, and the cause of the lateral carrier diffusion between sensor cells. And the improvement of smear and NTF is improved. In the embodiment described above, the present invention can be applied not only to Si but also to other semiconductor materials. Further, it can be used in a structure in which n and p are all replaced.

Further, as in the above embodiments, the characteristics of the transistor can be improved by lowering the collector resistance (specifically, the characteristics of the transistor,
Switching characteristics and the like can be improved). The above-described embodiment makes it possible to achieve the above-mentioned object more effectively.

[0051] Figure 11 is a schematic sectional view for explaining the sixth embodiment of the photoelectric converter of the present invention. This embodiment is a photoelectric converter in which the anode of the photodiode and the base region of the bipolar transistor are manufactured in different steps.

In the figure, 1001 is a p-type substrate, 1002 is an n-type buried layer which is a collector of a bipolar transistor, 1003 is an n ^- epitaxial layer,
Reference numeral 1004 denotes a p-layer serving as a base region of a bipolar transistor as an amplifying unit; 1005, a p-layer serving as an anode of a photodiode serving as a photoelectric conversion unit; 1006, an n-layer serving as an emitter region of the bipolar transistor;
_7-1 consists of a conductive material such as Al, wiring connecting the p layer 1004 is a base region of the p layer 1005 and the bipolar transistor is an anode of the photodiode, 10
_07-2 denotes an emitter electrode made of a conductive material such as Al or polysilicon, and 1008 denotes a LOCOS oxide film. L indicates a light receiving unit, and D indicates a light shielding unit.

[0053] As shown in the figure, the bipolar transistor is provided in the light shielding portion and the photodiode is provided on the light receiving unit are connected by a wiring 1007 _-1, to form a light shielding portion and the light receiving unit at a certain distance It becomes possible. When using a photoelectric converter of the present invention as a color line sensor, receiving the line sensor for red (R), as shown in FIG. 13
The light unit 12 and the light receiving unit 12 of the line sensor for green (G)
Arranged adjacently, the light-shielding part 11 of the green line sensor
(B) can be arranged outside the line sensor.
You. Therefore, when the R signal of a certain line of the document is obtained, the G signal is the position of the document on the second line from that line, B
The signal becomes each signal of the document position of the (n + 3) th line,
The R, B, and G signals are respectively applied to the sample and hold circuit (S /
H) 14, the signal is processed through the A / D conversion circuit 15,
At least the GB signal is stored in the external memory 102.
At this time, the amount of the previously output GB signal to be stored is reduced as compared with the color line sensor of FIG. 16 described above, and the capacity of the external memory can be smaller. As in FIG. 16, the light-shielding portion is an integer of the width of the light-receiving portion.
It has twice the width.

In this embodiment, the impurity diffusion of the p-layer 1004, which is the base region of the bipolar transistor, and the p-layer 1005, which is the anode of the photodiode, are independently controlled. Can be controlled independently, and the spectral sensitivity characteristics of the photodiode can be adjusted to a desired wavelength sensitivity.
In addition, it is possible to set characteristics such as the amplification factor and the response speed of the bipolar transistor to desired optimum values.

[0055] FIG. 12 is a schematic sectional view for explaining a seventh embodiment of the photoelectric converter of the present invention. In the present embodiment, a p ⁺ region is formed in a bipolar transistor,
The collector region of the bipolar transistor is a photoelectric converter manufactured separately. The same components as those in the above-described sixth embodiment are denoted by the same reference numerals, and description thereof is omitted.

[0056] In the figure, 1004 _-1 p layer is the anode of the photodiode, 1004 _-2 a p layer is a base region of a bipolar transistor is fabricated simultaneously. 1006 _-2 a n-layer is an emitter region of a bipolar transistor. Reference numeral 1009 denotes a p ⁺ layer in which a high impurity concentration region is provided for improving frequency characteristics. Reference numeral 1010 denotes an n layer which is a collector region of the bipolar transistor, 1006 _-3 denotes an n ⁺ layer, 1007
_-3 is a collector electrode made of a conductive material such as Al or polysilicon. n ^- layer 1003 is your contact with the p-layer 1004 _-1
Ri, n layer 1010 electrically to the collector electrode 1007 _-3
It is connected. p ⁺ layer 1009 and p layer 1004 _-2 increase
Configure the input part of the width part (bipolar transistor)
, The impurity concentration of the p ⁺ layer 1009 is
_−2, and the p ⁺ layer 1009 is
To p layer 1004 _-1 it is connected through a wiring 1007 _-1 consisting
ing.

[0057] are connected as shown in the figure, the bipolar transistor wiring 1007 _-1 provided to the photodiode and the light shielding portion provided in the light receiving portion which are separately formed,
The same effects as in the sixth embodiment can be obtained, and the color line sensor shown in FIG. 13 can be configured.

Next, an example of an image reading apparatus using the photoelectric converter of the present invention described above. FIG. 14 is a schematic configuration diagram of an example of the image reading device. In FIG.
Reference numeral 201 mechanically moves relative to the reading unit 5205 in the arrow Y direction. In addition, reading of an image is performed by scanning the image sensor 5204 in the arrow X direction.

First, the light from the light source 5202 is
1 and the reflected light passes through the imaging optical system 5203
An image is formed on the image sensor 5204 according to the present invention . As a result, carriers corresponding to the intensity of incident light are accumulated in the image sensor 5204, photoelectrically converted, and output as image signals. This image signal is converted into a digital signal by an AD converter 5206, and the image
Is captured as image data in a memory inside the printer. And
Processing such as shading correction and color correction is performed and transmitted to the personal computer 5208 or a printer.

When the transfer of the image signal for the scanning in the X direction is completed in this manner, the original 5201 relatively moves in the Y direction, and the same operation is repeated thereafter, thereby converting the previous image of the original 5201 into an electric signal and converting the image into image information. Can be taken out as

[0061]

As described in detail above, the light of the present invention
According to the electric converter, the input region of the amplification unit and the photoelectric conversion unit can be manufactured independently, and the size, impurity concentration, configuration, and the like of the diffusion region can be controlled independently, and the spectral characteristics of the photoelectric conversion unit can be controlled. Sensitivity characteristics can be adjusted to desired wavelength sensitivity, and characteristics such as amplification rate and response speed of the amplifier can be set to desired optimum values, and devices having desired performance can be designed. it can.

Further, according to the above-mentioned photoelectric converter , the impurity concentration of the semiconductor region which generates and accumulates electric charge by light incidence,
Optimal manufacturing conditions such as thickness and base of semiconductor transistor
The impurity concentration of the semiconductor region serving as a region, the impurity concentration distribution,
Optimal manufacturing conditions such as thickness can be arbitrarily set in each semiconductor region. As a result, the light receiving section and the semiconductor transistor section can be separately designed, and the blue sensitivity can be increased, and the speed of the semiconductor transistor can be increased.

Further , according to the photoelectric converter of the present invention, it is possible to provide an amplifying function, separate the light receiving portion and the light shielding portion from each other, and to form the light receiving portion adjacently.
As a result, system design and optical design can be simplified. A photoelectric converter formed by dividing a semiconductor region of the opposite conductivity type into a semiconductor region that accumulates charges generated by light incidence and a semiconductor region serving as a base region of a semiconductor transistor, and a photoelectric conversion unit as a light receiving unit. formed, the amplifying section is formed in the shielding portion, wherein the photoelectric conversion unit input region of the amplifying section by wired, the light receiving portion and said light shielding portion at a predetermined distance separating the formed photoelectric conversion By combining with the device , the performance can be further improved.

Further , according to the image processing apparatus of the present invention,
Reduce the amount of previously output signals that should be stored and
The capacity of Molly can be made smaller. Also book
According to the photoelectric conversion device of the present invention, reading is performed by the adjacent light receiving unit.
To get information on the object to be
Can take out the signal from the adjacent light shield
it can.

[Brief description of the drawings]

[1] (A), (B) is a schematic diagram for explaining a first embodiment of a photoelectric converter of the respective present invention,
(A) is a schematic plan view, (B) is a schematic longitudinal sectional view.

FIG. 2A is a sectional view taken along the line BB ′ of FIG.
It is a typical enlarged view when (B) is cut, and (B) is a potential diagram in the depth direction of (A).

FIG. 3 is a characteristic diagram illustrating an absorption coefficient with respect to wavelengths of light of Si and Ge.

FIG. 4 is a characteristic diagram illustrating the relationship between the p ⁻ impurity density NA and the total depletion layer width W at a reverse bias voltage VR = 5V.

FIG. 5 is a characteristic diagram illustrating a relationship between a p ⁻ impurity density NA and a thickness xp of a p-layer depletion layer.

6 is a schematic circuit diagram for explaining an embodiment of a drive circuit of a photoelectric converter according to the invention.

FIG. 7 is a schematic cross-sectional view for explaining a second embodiment of the present invention.

FIG. 8 is a schematic sectional view for explaining a third embodiment of the present invention.

FIG. 9 is a schematic sectional view for explaining a fourth embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view for explaining a fifth embodiment of the present invention.

11 is a schematic sectional view for explaining the sixth embodiment of the photoelectric converter of the present invention.

12 is a schematic sectional view for explaining a seventh embodiment of the photoelectric converter of the present invention.

13 is a schematic configuration diagram for the image reading system is described using a photoelectric converter of the present invention.

FIG. 14 is a schematic configuration diagram of an example of an image reading apparatus.

15 is a schematic cross-sectional view illustrating the structure of a conventional photoelectric converter.

16 is a schematic diagram for explaining an image reading system using the conventional photoelectric converter.

17] (A) is a schematic plan view of a configuration example of the photoelectric converter, (B) is a schematic cut sectional view, cut the (A) in line A-A '(A) It is.

FIGS. 18A and 18B are voltage waveform diagrams for explaining a refresh operation, respectively.

[Explanation of symbols]

4001 silicon substrate 4002 buried region 4003 n ^- region 4004 p ^- region 4005 p ⁺ region 4006 n ⁺ region 4007 p ⁺ region 4008 n ⁺ region 4009 n ⁺ region 4101 electrode 4102, 4103, 4104, 4108, 4109,
4110 electrode wiring 4105, 4106, 4107 insulating film

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 27/146 H04N 1/028 H04N 5/335

Claims (16)

(57) [Claims] A plurality of sets each including a light receiving section and a light blocking section, wherein a photoelectric conversion section is provided in the light receiving section, and an amplification section is provided in the light blocking section to amplify an output from the photoelectric conversion section. Provided, the photoelectric conversion unit and the input area of the amplification unit are connected through a wiring, at least one of the light shielding units is separated by a predetermined distance from the light receiving unit, and at least two of the light receiving units are mutually separated. Photoelectric converters in adjacent relationship. 2. The photoelectric converter according to claim 1, wherein an input region of said amplification unit to which a wiring is connected from said photoelectric conversion unit.
A photoelectric converter having regions having the same conductivity type and at least regions having different impurity concentrations. 3. A photoelectric converter according to claim 2, prior
A photoelectric converter in which a high impurity concentration region between regions having different impurity concentrations constituting an input region of the amplification unit is connected to the photoelectric conversion unit via a wiring. 4. and a plurality of light receiving elements arranged in a line three light receiving portion comprising respectively each for taking out a signal from each of the light receiving portion
A light shielding unit provided along the light receiving unit, a signal processing unit for processing a signal extracted from each light receiving unit, and a memory unit for storing the signal processed by the signal processing unit If, in the image processing apparatus having, with at least two light-receiving side with each other among the three light receiving portions arranged in a line are arranged adjacent to each other, the light shielding portion is said that according to the light receiving portion An image processing apparatus, which is disposed on a side opposite to a side adjacent to a light receiving section. 5. The image processing apparatus according to claim 4, wherein
The image processing device, wherein the light receiving unit is a line sensor corresponding to at least red, green, and blue. 6. The image processing apparatus according to claim 4, wherein
An image processing device, wherein the signal processing unit has a sample hold circuit or an A / D conversion circuit. 7. The image processing apparatus according to claim 4, wherein
The image processing device, wherein the memory unit is an external memory. 8. The image processing apparatus according to claim 4, wherein
An image processing apparatus having a light source for irradiating a document having information to be read. 9. The image processing apparatus according to claim 4, wherein
An image processing apparatus further comprising an optical unit for forming an image of image information input to the light receiving unit. 10. The image processing apparatus according to claim 4, wherein said memory unit is provided in the image processing unit. 11. The image processing apparatus according to claim 10, wherein said image processing unit has a function of shading correction or color correction. 12. The image processing apparatus according to claim 4, further comprising moving means for relatively moving a document having information to be read and said light receiving section. 13. An image processing apparatus according to claim 4, wherein said light receiving portion and said light blocking portion have at least a portion arranged in the order of a light blocking portion, a light receiving portion, a light receiving portion, and a light blocking portion. 14. An image processing apparatus according to claim 13 , wherein said light receiving section and said light shielding section are arranged in the order of the light receiving sections for reading information to be read. 15. Information corresponding to at least red, green, and blue.
A line sensor comprising: a light receiving section in which a plurality of light receiving elements are arranged in a line to read the light; and a light blocking section provided along the light receiving section of the line sensor to extract a signal from the light receiving element of the light receiving section. a a plurality, one of the line sensor of the light receiving portion and another adjacent light-receiving portion of the line sensors are arranged the line sensor to be provided adjacent to that photoelectric conversion device for arrangement in the line sensor. 16. The photoelectric conversion device according to claim 15 , wherein the light receiving section and the light blocking section are at least a light blocking section, a light receiving section,
A photoelectric conversion device having a part arranged in the order of a light receiving part and a light shielding part.