JP2005268564A - Solid-state imaging device and manufacturing method of solid-state imaging device - Google Patents

Abstract

The present invention relates to a solid-state imaging device that suppresses deterioration of afterimage characteristics at low cost and without causing a decrease in dynamic range, and a method for manufacturing the solid-state imaging device.
A solid-state imaging device 1 has a charge readout side of charges photoelectrically converted by a photoelectric conversion unit 2 on an upper layer of a second conductivity type region 4 constituting a photoelectric conversion unit 2 together with a substrate region 3 of a first conductivity type. A conductive material 6 having optical transparency is formed through an insulating film 5 from the potential application side opposite to the charge readout side, and a voltage application unit is provided on the charge readout direction side of the conductive material 6 and on the opposite side thereof. 7 and the voltage application unit 8 are provided, and different voltages are applied to the voltage application unit 7 and the voltage application unit 8. The potential distribution of the second conductivity type region 4 is inclined by the potential distribution generated in the conductive material 6, the signal charge is moved to the charge reading side, and the afterimage phenomenon due to the unread reading of the charge is suppressed at a low cost, High-speed reading can be performed.
[Selection] Figure 2

Description

  The present invention relates to a solid-state imaging device and a method for manufacturing the solid-state imaging device, and more particularly, to a solid-state imaging device that suppresses deterioration of afterimage characteristics at low cost and without causing a decrease in dynamic range, and a method for manufacturing the solid-state imaging device. .

  In recent years, with the increase in signal processing speed, the readout time of signal charges in a solid-state image sensor has also become shorter. When the signal charge readout time in the solid-state image sensor is shortened, the afterimage phenomenon caused by unreading the signal charge in the photoelectric conversion unit has become a problem. Is required.

  In the circuit configuration shown in FIG. 12, the signal charge stored in the photoelectric conversion unit is read out by applying a voltage to the charge read gate 101 of the MOS structure adjacent to the photoelectric conversion unit, so that the potential immediately below the read gate 101 becomes photoelectric. It becomes higher than the potential of the conversion unit, and the signal charge is transferred to the transfer gate 101. In the circuit configuration example shown in FIG. 13, the potential of the photoelectric conversion unit is directly connected to the amplifier, and the potential at the connection point is read out.

  However, since the potential structure of the photoelectric conversion unit is generally flat in the charge reading direction, the charge transfer rate in the photoelectric conversion unit is slow, and it takes time to completely read out the signal charge. Further, it is difficult to completely read out all signal charges.

  Conventionally, as a solid-state imaging device manufacturing technique, a technique has been reported in which a diffusion layer of a photodiode is divided into a plurality of regions and the impurity concentration in each region is changed. That is, as shown in FIG. 14A, the photodiode region is divided into three regions 201, 202, and 203, and each region 201, 202, and 203 is subjected to P using photolithography and ion implantation techniques. An N-type impurity is introduced into the mold substrate 200. At this time, the amount of ion implantation is controlled so that the impurity concentration increases in order according to the reading direction, that is, the impurity concentration satisfies region 203> region 202> region 201. Since the potentials 201p to 203p of the regions 201 to 203 of the photodiode portion depend on the impurity concentration, as shown in FIG. 14B, potentials 201p to 203p that increase in the order of region 201 <region 202 <region 203 are formed. Is done. Since the signal charge moves to the high potential portion, forming the photodiode composed of the photodiode regions 201 to 203 in which the impurity concentration is changed eliminates the unread reading of the charge, and enables high-speed reading. It is realizable (refer patent document 1).

  However, in this example, it is necessary to perform photoengraving and ion implantation for forming a photodiode a plurality of times, and as the number of steps increases, the cost increases and the potential distribution within each same concentration region is increased. Since it becomes flat, it is necessary to further improve the movement of signal charges within the same concentration region.

  Conventionally, as shown in FIG. 15, a technique of laying out so that the impurity diffusion layer 300 serving as a photodiode is branched in a direction opposite to the charge reading direction has been reported. In this case, the same conductive impurities as the substrate introduced to prevent the inversion of the parasitic transistor in the substrate region 301 serving as the LOCOS diffuse in the lateral direction to the photodiode diffusion region. As a result, the effective impurity concentration of the photodiode diffusion decreases.

  Therefore, by creating an impurity distribution whose concentration decreases in the direction opposite to the reading direction, a potential distribution that increases in the reading direction is formed as in the case of FIG.

JP 2000-150853 A

  However, in the prior art shown in FIG. 15, since the area of the photodiode is reduced, the junction capacitance of the photodiode is reduced, the dynamic range is reduced, the image characteristics are deteriorated, and the aperture is opened. There was a problem that the sensitivity was lowered due to the decrease in the rate.

  Therefore, an object of the present invention is to provide a solid-state imaging device and a manufacturing method of the solid-state imaging device that can suppress deterioration of afterimage characteristics at low cost without causing a decrease in dynamic range.

  Specifically, in the first aspect of the present invention, a conductive material having light transmissivity is formed on an upper layer of the second conductivity type region constituting the photoelectric conversion portion together with the first conductivity type substrate region via an insulating film. Forming a voltage application section on the charge readout side of the conductive material and the opposite side thereof, and applying a voltage so that the voltage application section on the charge readout side has a higher potential, thereby forming the conductive material The potential distribution corresponding to the potential generated in the conductive material is generated near the surface of the second conductivity type region, and the signal charge generated in the photoelectric conversion unit is transferred to the charge readout side having a high potential. An object of the present invention is to provide a solid-state imaging device that can be moved to suppress an afterimage phenomenon caused by unread reading of charges at a low cost and perform high-speed reading.

  According to the second aspect of the present invention, an electrically conductive material having light transmittance through an insulating film is formed on the upper layer of the second conductivity type region constituting the photoelectric conversion unit together with the first conductivity type substrate region. A plurality of photoelectrically converted charges are formed in a strip shape extending in a direction substantially orthogonal to the charge readout direction, and a voltage that is higher in potential as the conductive material on the charge readout side is applied to the plurality of conductive materials. By generating a potential distribution deeper toward the charge readout side in the second conductivity type region, the signal charge generated in the photoelectric conversion unit is moved to the charge readout side having a higher potential, and the afterimage phenomenon is suppressed at a low cost, Providing a solid-state imaging device with low current consumption by enabling high-speed readout and forming a potential distribution in the second conductivity type region while reducing current consumption by preventing current from flowing through the conductive material. To do It is the target.

  According to a third aspect of the present invention, a depletion layer is generated by forming a light-transmitting conductive material on a first conductive type substrate region via an insulating film and applying a voltage to the conductive material. As a light receiving part, a voltage application part is formed on the charge reading side and the opposite side of the conductive material, and a voltage that is higher in the voltage application part on the charge reading side is applied to the conductive material. A potential distribution corresponding to the potential generated in the conductive material is generated near the surface of the substrate with the potential distribution, and the signal charge generated in the photoelectric conversion unit is moved to the charge reading side having a high potential to generate the charge. An object of the present invention is to provide a solid-state imaging device capable of suppressing the afterimage phenomenon caused by the unreadness of the image at low cost and performing high-speed reading.

  According to a fourth aspect of the present invention, a depletion layer is generated by forming a light-transmitting conductive material on a first conductivity type substrate region via an insulating film and applying a voltage to the conductive material. Are formed as a plurality of conductive materials extending in a strip shape in a direction substantially perpendicular to the charge reading direction of the charges photoelectrically converted by the light receiving portions, and charge is applied to the plurality of conductive materials. By applying a higher voltage to the readout side conductive material, a deeper potential distribution is generated in the substrate toward the charge readout side, and the signal charge generated in the photoelectric conversion unit is moved to the charge readout side with a higher potential. Therefore, the afterimage phenomenon can be suppressed at low cost and high-speed readout can be performed, and the current is not passed through the conductive material, thereby reducing the current consumption and forming a potential distribution in the substrate. Less solid photography And its object is to provide a device.

  According to a fifth aspect of the present invention, the conductive material according to any one of the first to fourth aspects is formed at the same time as the gate electrode of the transistor in the step of forming the gate electrode of the CMOS process. It aims at providing the manufacturing method of the solid-state image sensor which manufactures the solid-state image sensor which suppressed the afterimage phenomenon.

  In the solid-state imaging device according to the first aspect of the present invention, a light-transmitting conductive material is formed on an upper layer of the second conductive type region constituting the photoelectric conversion portion together with the first conductive type substrate region through an insulating film. In addition, a voltage application section is formed on the charge reading side and the opposite side of the conductive material, and a higher voltage is applied to the voltage reading section on the charge reading side, thereby achieving the above object.

  In the solid-state imaging device according to the second aspect of the present invention, a conductive material having light transmittance through an insulating film is formed on the upper layer of the second conductivity type region constituting the photoelectric conversion unit together with the first conductivity type substrate region. A plurality of strips extending in a direction substantially perpendicular to the charge reading direction of charges photoelectrically converted by the photoelectric conversion unit are formed, and the higher the conductive material on the charge reading side, the higher the conductive material on the charge reading side. The above object is achieved by applying a voltage to be a potential.

  According to a third aspect of the present invention, there is provided a solid-state imaging device in which a light-transmitting conductive material is formed on a first conductive type substrate region via an insulating film, and a voltage is applied to the conductive material. In a solid-state imaging device using a generated depletion layer as a light receiving portion, a voltage application portion is formed on the opposite side to the charge reading side of the conductive material, and a higher voltage is applied to the voltage reading portion on the charge reading side. The above-mentioned purpose is achieved.

  According to a fourth aspect of the present invention, there is provided a solid-state imaging device in which a light-transmitting conductive material is formed on a first conductive type substrate region via an insulating film, and a voltage is applied to the conductive material. In the solid-state imaging device using the generated depletion layer as a light receiving portion, a plurality of the conductive materials are formed to extend in a band shape in a direction substantially orthogonal to the charge reading direction of the charge photoelectrically converted by the light receiving portion. The above object is achieved by applying a voltage having a higher potential to the plurality of conductive materials as the conductive material on the charge readout side.

  A method for manufacturing a solid-state image sensor according to a fifth aspect of the present invention is a method for manufacturing a solid-state image sensor for manufacturing the solid-state image sensor according to any one of the first to fourth aspects. The above object is achieved by forming the conductive material according to any one of 4 in the step of forming the gate electrode of the CMOS process at the same time as the gate electrode of the transistor.

  According to the solid-state imaging device of the first aspect of the present invention, the conductive material having light transmissivity on the upper layer of the second conductivity type region constituting the photoelectric conversion portion together with the first conductivity type substrate region via the insulating film. Forming a voltage application portion on the charge reading side of the conductive material and the opposite side thereof, and applying a voltage so that the voltage application portion on the charge reading side has a higher potential. Potential distribution according to the potential generated in the conductive material can be generated near the surface of the second conductivity type region, and the signal charge generated in the photoelectric conversion unit can be By moving to the reading side, the afterimage phenomenon caused by the unread reading of the charges can be suppressed at a low cost, and high-speed reading can be performed.

  According to the solid-state imaging device of the second aspect of the present invention, the conductive material having optical transparency on the upper layer of the second conductivity type region constituting the photoelectric conversion portion together with the first conductivity type substrate region via the insulating film. Are formed in a strip shape extending in a direction substantially orthogonal to the charge reading direction of the charge photoelectrically converted by the photoelectric conversion unit, and the higher the conductive material on the charge reading side, the higher the conductive material on the charge reading side. Since a potential voltage is applied, a potential distribution deeper toward the charge readout side is generated in the second conductivity type region, and the signal charge generated in the photoelectric conversion unit is moved to the charge readout side having a higher potential, thereby causing an afterimage phenomenon. In addition to being able to control at low cost, it is possible to perform high-speed reading, and by not passing current through the conductive material, a potential distribution is formed in the second conductivity type region while reducing current consumption. Power consumption It can be reduced.

  According to the solid-state imaging device of the third aspect of the present invention, the conductive material having optical transparency is formed on the substrate region of the first conductivity type via the insulating film, and a voltage is applied to the conductive material. Since the depletion layer generated by this is used as a light receiving part, a voltage application part is formed on the charge reading side of the conductive material and the opposite side, and the voltage application part on the charge reading side applies a higher voltage. The potential distribution according to the potential generated in the conductive material can be generated near the surface of the substrate by giving the potential distribution to the conductive material, and the signal charge generated in the photoelectric conversion unit can be By moving to the reading side, the afterimage phenomenon caused by the unread reading of the charges can be suppressed at a low cost, and high-speed reading can be performed.

  According to the solid-state imaging device of the fourth aspect of the present invention, a conductive material having optical transparency is formed on the first conductive type substrate region via the insulating film, and a voltage is applied to the conductive material. The depletion layer generated in this way is used as a light receiving portion, and the conductive material is formed in a plurality of strips extending in a band shape in a direction substantially perpendicular to the charge reading direction of the charge photoelectrically converted by the light receiving portion. Since a voltage having a higher potential is applied to the conductive material as the conductive material on the charge reading side, a deeper potential distribution is generated in the substrate toward the charge reading side, and the signal charge generated in the photoelectric conversion unit has a higher potential. By moving to the charge readout side, the afterimage phenomenon can be suppressed at low cost, high-speed readout can be performed, and current consumption can be reduced by not passing current through the conductive material. it can.

  According to a method for manufacturing a solid-state imaging device of a fifth aspect of the present invention, the conductive material according to any one of the first to fourth aspects of the present invention is formed in a step of forming a gate electrode of a CMOS process. Since it is formed at the same time, it is possible to manufacture a solid-state imaging device that suppresses the afterimage phenomenon at low cost.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The scope of the present invention limits this invention especially in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

  1 to 4 are diagrams showing a first embodiment of a solid-state imaging device and a manufacturing method of the solid-state imaging device according to the present invention. FIG. 1 shows a first example of the solid-state imaging device and the manufacturing method of the solid-state imaging device according to the present invention. 1 is a plan view of a solid-state imaging device 1 to which one embodiment is applied, and FIG.

  1 and 2, the solid-state imaging device 1 includes an insulating film 5 on the first conductive type substrate region (P) 3 and the second conductive type (N−) region 4 constituting the photoelectric conversion unit 2. A light-transmitting conductive material (electrode) 6 is disposed therethrough. In the solid-state imaging device 1, a voltage application unit 7 is provided on the charge reading side of the photodiode of the conductive material 6, and a voltage application unit 8 is provided on the side opposite to the voltage application unit 7.

  In the solid-state imaging device 1, the conductive material 6 is formed at the same time as the step of forming polysilicon that serves as an electrode of a transistor used in a conventional CMOS process. In this case, the thickness of the polysilicon layer is controlled to such an extent that light absorption by the polysilicon does not affect the sensitivity of the solid-state imaging device 1.

Further, as the conductive material 6 disposed on the upper layer of the photodiode via the insulating film 5, a transparent electrode material such as ITO, SnO ₂ , ZnO or the like may be used in addition to polysilicon.

  In the solid-state imaging device 1, when a voltage that satisfies the voltage application unit 7> the voltage application unit 8 is applied to the voltage application unit 7, a current flows through the conductive material 6.

  At this time, since the conductive material 6 has a certain electric resistance, the potential of the conductive material 6 sequentially increases from the voltage application unit 8 side toward the voltage application unit 7 side as shown in FIG. . The potential near the surface of the second conductivity type (N−) region 4 in the substrate generated by the potential of the conductive material 6 is directed from the voltage application unit 8 side to the voltage application unit 7 side as shown in FIG. And gradually increase.

  Therefore, the charge generated by the light irradiation moves to the charge reading side along this potential gradient.

  As described above, the solid-state imaging device 1 according to the present embodiment has light transmittance through the insulating film 5 on the upper layer of the second conductivity type region 4 constituting the photoelectric conversion unit 2 together with the first conductivity type substrate region 3. The conductive material 6 is formed, the voltage application unit 7 and the voltage application unit 8 are formed on the charge reading side of the conductive material 6 and the opposite side thereof, and the voltage application unit 7 and the voltage application unit 8 are subjected to the voltage application. The unit 7 applies a voltage having a higher potential than the voltage application unit 8.

  Therefore, the conductive material 6 can have a potential distribution, and a potential distribution corresponding to the potential generated in the conductive material 6 can be generated near the surface of the second conductivity type region 4. The generated signal charge can be moved to the charge reading side having a high potential, so that the afterimage phenomenon caused by unread reading of charges can be suppressed at a low cost and high-speed reading can be performed.

  5 to 7 are diagrams showing a second embodiment of the solid-state imaging device and the manufacturing method of the solid-state imaging device of the present invention, and FIG. 5 is a diagram of the solid-state imaging device of the present invention and the manufacturing method of the solid-state imaging device. FIG. 6 is a plan view of the solid-state imaging device 10 to which the second embodiment is applied, and FIG.

  5 and 6, in the solid-state imaging device 10, the photoelectric conversion unit 11 includes a first conductivity type substrate region 12 and a second conductivity type (N−) region 13, and this second conductivity type (N -) A plurality of electrodes 15 a to 15 f made of a strip-like conductive material having light permeability are formed on the region 13 through the insulating film 14. These electrodes 15a to 15f are sequentially given higher voltages as they approach the reading direction.

  In the solid-state imaging device 10, the electrodes 15 a to 15 f made of a conductive material are formed simultaneously with the step of forming polysilicon that serves as an electrode of a transistor used in a conventional CMOS process. In this case, the film thickness of the polysilicon layer is controlled to such an extent that light absorption by the polysilicon does not affect the sensitivity of the solid-state imaging device 10.

In addition to polysilicon, a transparent electrode material such as ITO, SnO ₂ , or ZnO may be used as the conductive material that becomes the electrodes 15 a to 15 f disposed above the photodiode via the insulating film 14.

  The solid-state imaging device 10 is an electrode made of a conductive material formed on an upper layer of a first conductivity type substrate region 12 and a second conductivity type (N−) region 13 constituting the photoelectric conversion unit 11 via an insulating film 14. When a higher potential is sequentially applied to the reading direction in 15a to 15f, as shown in FIG. 7, a higher stepwise potential distribution is obtained as the reading direction is approached, that is, as the electrode 15f moves from the electrode 15a to the electrode 15f. The optical signal charge can be moved to the reading side.

  As described above, the solid-state imaging device 10 according to the present exemplary embodiment has light transmittance through the insulating film 14 on the upper layer of the second conductivity type region 13 constituting the photoelectric conversion unit 11 together with the first conductivity type substrate region 12. A plurality of electrodes 15a to 15f made of a conductive material are formed extending in a band shape in a direction substantially orthogonal to the charge reading direction of the charges photoelectrically converted by the photoelectric conversion unit 11, and the plurality of conductive materials A voltage having a higher potential than the electrodes 15a to 15f of the conductive material on the charge readout side is applied to the electrodes 15a to 15f.

  Therefore, a deeper potential distribution is generated in the second conductivity type region 13 toward the charge reading side, and the signal charge generated in the photoelectric conversion unit 11 is moved to the charge reading side having a higher potential, thereby suppressing the afterimage phenomenon at low cost. In addition to being able to perform high-speed reading, a current distribution is not applied to the electrodes 15a to 15f made of the conductive material, so that a potential distribution is formed in the second conductivity type region 13 while reducing current consumption. Thus, current consumption can be reduced.

  8 and 9 are diagrams showing a third embodiment of the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, and FIG. 8 is a diagram illustrating the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention. FIG. 9 is a cross-sectional view taken along the line CC in FIG. 8. FIG. 9 is a plan view of the solid-state imaging device 20 to which the third embodiment is applied.

  8 and 9, the solid-state imaging device 20 is a conductive material having optical transparency through an insulating film 22 without providing a second conductive type layer on the first conductive type substrate region (P) 21. An electrode 23 of material is provided, and a voltage application unit 24 and a voltage application unit 25 are formed on the charge reading side of the electrode 23 of the conductive material and the opposite side thereof, and the voltage application unit 24 is connected to the voltage application unit 25. A voltage having a higher potential is applied.

  In the solid-state imaging device 20, a readout gate 26 is formed on the charge readout section 29 side at a predetermined interval from the electrode 23 of the conductive material. The readout gate is provided in the first conductivity type substrate region (P) 21. 26, a diffusion layer 28 and a diffusion layer 27 are formed on the electrode 23 side and the charge readout unit 29 side of the conductive material.

  That is, the solid-state imaging device 20 uses a depletion layer on the surface of the substrate 21 generated by applying a voltage to the electrode 23 of the conductive material disposed on the substrate 21 via the insulating film 22 as a light detection unit. It is an image sensor.

  In the solid-state imaging device 20, the electrode 23 made of a conductive material is formed at the same time as the step of forming polysilicon that serves as an electrode of a transistor used in a conventional CMOS process. In this case, the thickness of the polysilicon layer is controlled to such an extent that light absorption by the polysilicon does not affect the sensitivity of the solid-state imaging device 20.

In addition to polysilicon, a transparent electrode material such as ITO, SnO ₂ , or ZnO may be used as the conductive material that becomes the electrode 23 disposed on the upper layer of the photodiode via the insulating film 22.

  In the solid-state imaging device 20, when the voltage application unit 24 and the voltage application unit 25 are applied with a voltage that is higher in the voltage application unit 24 and a potential distribution is generated in the electrode 23 of the conductive material, the substrate 21 Inclination occurs in the potential generated near the surface of the light, and the optical signal charge moves to the charge readout side. This signal charge is transferred to the diffusion layer 28 and then applied to the read gate 26, so that the signal charge is transferred to the diffusion layer 27 and output to the subsequent amplifier.

  As described above, the solid-state imaging device 20 according to the present embodiment forms the electrode 23 with the light-transmitting conductive material on the first conductive type substrate region 21 through the insulating film 22, and Using a depletion layer generated by applying a voltage to the electrode 23 as a light receiving portion, a voltage applying portion 24 and a voltage applying portion 25 are formed on the charge reading side and the opposite side of the conductive material. The voltage application unit 24 applies a voltage that is higher than the voltage application unit 25 to the voltage application unit 25.

  Therefore, the potential distribution can be generated in the vicinity of the surface of the substrate region 21 in accordance with the potential generated in the electrode 23 of the conductive material by giving the potential distribution to the electrode 23 of the conductive material. The generated signal charge can be moved to the charge reading side having a high potential, so that the afterimage phenomenon caused by unread reading of charges can be suppressed at a low cost and high-speed reading can be performed.

  10 to 11 are diagrams showing a fourth embodiment of the solid-state imaging device and the manufacturing method of the solid-state imaging device of the present invention, and FIG. 10 is a diagram of the solid-state imaging device of the present invention and the manufacturing method of the solid-state imaging device. The top view of the solid-state image sensor 30 to which 4 Example is applied, FIG. 11 is DD sectional drawing of FIG.

  10 and 11, the solid-state imaging device 30 is a conductive material having optical transparency through an insulating film 32 without providing a second conductive type layer on the first conductive type substrate region (P) 31. A plurality of electrodes 33a to 33f are formed of a material, and a charge reading gate 34 is provided on the charge reading side of the electrodes 33a to 33f of the conductive material. In the solid-state imaging device 30, a diffusion layer 35 is formed on the side opposite to the light receiving portion of the charge readout gate 34.

  In the solid-state imaging device 30, the electrodes 33a to 33f made of a conductive material are formed at the same time as the step of forming polysilicon to be an electrode of a transistor used in a conventional CMOS process. In this case, the thickness of the polysilicon layer is controlled to such an extent that light absorption by the polysilicon does not affect the sensitivity of the solid-state imaging device 30.

In addition to polysilicon, a transparent electrode material such as ITO, SnO ₂ , or ZnO may be used as the conductive material that becomes the electrodes 33a to 33f disposed above the photodiode via the insulating film 32.

  Then, when the solid-state imaging element 30 applies voltages that sequentially increase in the reading direction to the electrodes 33a to 33f of the conductive material, as in FIG. Can do. Therefore, signal charges are easily transferred to the diffusion layer 35 by applying a voltage to the charge readout gate 34.

  As described above, the solid-state imaging device 30 according to the present embodiment forms the electrodes 33a to 33f with the light-transmitting conductive material on the first conductivity type substrate region 31 through the insulating film 32, thereby forming the conductive material. A depletion layer generated when a voltage is applied to the electrodes 33a to 33f is used as a light receiving portion, and the electrodes 33a to 33f of the conductive material are substantially orthogonal to the charge reading direction of the electric charge photoelectrically converted by the light receiving portion. A plurality of conductive material electrodes 33a to 33f are applied to the plurality of conductive material electrodes 33a to 33f.

  Accordingly, a deeper potential distribution is generated on the charge reading side on the substrate 31, and the signal charge generated in the photoelectric conversion unit is moved to the charge reading side having a higher potential, so that the afterimage phenomenon can be suppressed at a low cost. In addition to being able to perform reading, it is possible to form a potential distribution in the substrate 31 while reducing current consumption by preventing current from flowing through the conductive material.

  In each embodiment, the conductive materials 6, 15a to 15f, 23, and 33a to 33f are formed at the same time as the gate electrode of the transistor in the step of forming the gate electrode of the CMOS process. Therefore, the solid-state imaging devices 1, 10, 20, and 30 that suppress the afterimage phenomenon can be manufactured at low cost.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention can be applied to a solid-state imaging device capable of suppressing an afterimage characteristic and operating at high speed without causing a decrease in dynamic range and a method for manufacturing the solid-state imaging device.

The top view of the solid-state image sensor to which the 1st example of the solid-state image sensor of the present invention and the manufacturing method of a solid-state image sensor is applied. AA arrow sectional drawing of the solid-state image sensor of FIG. The figure which shows the electric potential distribution of the electrode of the solid-state image sensor of FIG.1 and FIG.2. The figure which shows potential distribution near the surface of the 2nd conductivity type (N-) area | region in the board | substrate generated with the electric potential of the electrode of the solid-state image sensor of FIG.1 and FIG.2. The top view of the solid-state image sensor to which 2nd Example of the solid-state image sensor of this invention and the manufacturing method of a solid-state image sensor is applied. BB arrow sectional drawing of the solid-state image sensor of FIG. FIG. 7 is a diagram showing a potential distribution near the surface in the substrate generated by the potential of the electrodes of the solid-state imaging device of FIGS. 5 and 6. The top view of the solid-state image sensor to which 3rd Example of the solid-state image sensor of this invention and the manufacturing method of a solid-state image sensor is applied. CC arrow sectional drawing of the solid-state image sensor of FIG. The top view of the solid-state image sensor to which 4th Example of the solid-state image sensor of this invention and the manufacturing method of a solid-state image sensor is applied. DD sectional view of the solid-state imaging device of FIG. FIG. 3 is a diagram illustrating an example of a circuit configuration for reading signal charges from a photoelectric conversion unit of a solid-state imaging device. FIG. 10 is a diagram showing another example of a circuit configuration for reading out signal charges from the photoelectric conversion unit of the solid-state imaging device. The front expanded sectional view (a) of the conventional solid-state image sensor, and the figure (b) which show the potential of the photodiode part. The layout diagram of the other conventional solid-state image sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor 2 Photoelectric conversion part 3 1st conductivity type board | substrate area | region (P)
DESCRIPTION OF SYMBOLS 4 2nd conductivity type (N-) area | region 5 Insulating film 6 Conductive material 7 Voltage application part 8 Voltage application part 10 Solid-state image sensor 11 Photoelectric conversion part 12 1st conductivity type board | substrate area | region 13 2nd conductivity type (N-) area | region 14 Insulating film 15a-15f Electrode 20 Solid-state image sensor 21 1st conductivity type board | substrate area | region (P)
DESCRIPTION OF SYMBOLS 22 Insulating film 23 Electrode 24 Voltage application part 25 Voltage application part 26 Read gate 27, 28 Diffusion layer 29 Potential read part 30 Solid-state image sensor 31 1st conductivity type board | substrate area | region (P)
32 Insulating film 33a to 33f Electrode 34 Charge readout gate 35 Diffusion layer

Claims (5)

  A conductive material having optical transparency is formed on an upper layer of the second conductivity type region that constitutes the photoelectric conversion unit together with the substrate region of the first conductivity type through an insulating film. A solid-state imaging device, wherein a voltage application unit is formed on the opposite side, and a higher voltage is applied to the voltage application unit on the charge readout side.   A conductive material having a light transmitting property through an insulating film is formed on the second conductivity type region constituting the photoelectric conversion unit together with the substrate region of the first conductivity type, and the charge of the electric charge photoelectrically converted by the photoelectric conversion unit A plurality of strips extending in a direction substantially perpendicular to the readout direction are formed, and a voltage having a higher potential is applied to the plurality of conductive materials as the conductive material on the charge readout side. A solid-state imaging device.   A solid-state imaging device in which a light-transmitting conductive material is formed on a substrate region of the first conductivity type through an insulating film, and a depletion layer generated by applying a voltage to the conductive material is a light receiving unit In the solid-state imaging device, a voltage application section is formed on the charge reading side and the opposite side of the conductive material, and a higher voltage is applied to the voltage reading section on the charge reading side.   A solid-state imaging device in which a light-transmitting conductive material is formed on a substrate region of the first conductivity type through an insulating film, and a depletion layer generated by applying a voltage to the conductive material is a light receiving unit A plurality of the conductive materials are formed to extend in a band shape in a direction substantially orthogonal to the charge reading direction of the charges photoelectrically converted by the light receiving portion, and the charge reading is performed on the plurality of conductive materials. A solid-state imaging device, wherein a higher potential is applied to a conductive material on the side. 5. A method of manufacturing a solid-state imaging device for manufacturing the solid-state imaging device according to claim 1, wherein the conductive material according to any one of claims 1 to 4 is used in a CMOS process. A method for manufacturing a solid-state imaging device, wherein the step of forming a gate electrode is performed simultaneously with a gate electrode of a transistor.

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