JP2004228328A - Solid-state imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging device in which the process accuracy and uniformity of a transfer electrode of a plurality of layers are enhanced by a simple process method. <P>SOLUTION: A photodiode part 30, a transfer gate 4 and a vertical CCD (charge coupled device) part 50 are juxtaposed in a p-type well 2 provided in an n-type silicon substrate 1. Further, transfer electrodes 7, 8 are formed on the upper surfaces of the transfer gate 4 and the vertical CCD 50 through an oxide film 6. Further, the transfer electrode 7 of the first layer is buried in the p-type well 2, and the upper surface of the transfer electrode 7 is positioned flush with the upper surface of the photodiode 30. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solid-state imaging device having a plurality of layers of transfer electrodes.
[0002]
[Prior art]
In recent years, with the development of semiconductor integrated circuit technology, electronic devices or services that handle image information using charge coupled devices (hereinafter, referred to as CCDs) have become very familiar. The performance of CCDs has been increasing with the acceleration of semiconductor integrated circuit technology.
In general, a solid-state imaging device is formed on a semiconductor substrate of one conductivity type, a well of another conductivity type in which a photodiode portion, a transfer gate portion, and a vertical CCD portion are juxtaposed, and an upper surface of the transfer gate portion and the vertical CCD portion. A plurality of unit cells each having a plurality of transfer electrodes provided via an insulating film are arranged in an array (for example, see Patent Documents 1 and 2).
In the following, a case where the number of transfer electrodes is two is illustrated, but three or more layers may be used.
[0003]
FIG. 7 is a cross-sectional view of a unit cell provided in a conventional solid-state imaging device.
In the figure, reference numeral 1 denotes an N-type silicon substrate, and a P-type well 2 is provided in an upper region in the N-type silicon substrate 1. An N-type region 3 which is a part of the photodiode portion 30 is selectively provided inside the P-type well 2, and further, a vertical CCD is provided with a transfer gate portion 4 adjacent to the photodiode portion 30 interposed therebetween. An N-type well 5 which is a part of the unit 50 is provided.
[0004]
Further, a first-layer transfer electrode 7 and a second-layer transfer electrode 8 made of, for example, polysilicon are stacked on the upper surface of the transfer gate portion 4 and the upper surface of the N-type well 5 via an oxide film 6, respectively. Further, the upper and side surfaces of the transfer electrodes 7 and 8 are covered with a light shielding film 11 made of, for example, tungsten (hereinafter, referred to as W) via the oxide film 6. Each unit cell is separated by channel stoppers 9, 9, and a surface P + layer 10, which is a part of the photodiode 30, and an oxide film 6 are formed above the N-type region 3. . The channel stopper section 9 is adjacent to the photodiode section 30 (or the vertical CCD section 50) of one unit cell and the vertical CCD section 50 (or the photodiode section 30) of another unit cell.
Further, the flattening film 12 covers the upper side of the photodiode unit 30 and the vertical CCD unit 50, that is, the light-shielding film 11 and the oxide film 6, and furthermore, the flattening film 12 and the oxide film 6 On the upper side, a micro lens 13 is formed.
[0005]
FIG. 8 is a plan view of a transfer electrode included in a conventional solid-state imaging device. In this case, FIG. 7 corresponds to a cross-sectional view taken along line II in FIG. 8, and FIG. 9 described below corresponds to a cross-sectional view taken along line II-II in FIG.
(Or transfer electrodes 8, 8,...) Between transfer electrodes 7, 7,... (Or transfer electrodes 8, 8,...) (Or transfer electrodes 8, 8,. , 70, ... (intervals 80, 80, ...). In this case, an overlap region 78 in which the transfer electrodes 8 are stacked (via the oxide film 6) is provided on the transfer electrodes 7 in order to alternately apply a pulse voltage to the transfer electrodes 7 and 8 to sequentially transfer the pulse voltages. ing. That is, a solid-state imaging device requires two or more transfer electrodes.
[0006]
The shapes of the first-layer transfer electrodes 7, 7, ... and the second-layer transfer electrodes 8, 8, ... are respectively complicated, and the transfer electrodes 8, 8, ... to the transfer electrodes 7, 7, ... Are also very complicated.
When three or more transfer electrodes are formed, the shape becomes more complicated.
[0007]
FIG. 9 is an explanatory view of the procedure for forming the transfer electrodes 7 and 8 provided in the conventional solid-state imaging device, and the formation of the oxide film 6 and the semiconductor layer 20 shown in FIG. 7 is omitted. The semiconductor layer 20 includes the N-type silicon substrate 1, the P-type well 2, the photodiode unit 30, the transfer gate unit 4, the vertical CCD unit 50, and the channel stopper unit 9 shown in FIG.
[0008]
First, a polysilicon film serving as the transfer electrode 7 is formed on the semiconductor layer 20, and then a resist pattern 14 serving as a mask is formed by photolithography. (FIG. 9 (a)).
Next, by performing etching, the polysilicon film (unnecessary portion of the polysilicon film) not covered with the resist pattern 14 is removed to form the transfer electrodes 7, 7,..., And then the resist pattern 14 is removed. Further, a polysilicon film serving as the transfer electrode 8 is formed on the semiconductor layer 20 and the transfer electrodes 7, 7,... (FIG. 9B).
Next, after a resist pattern 14 serving as a mask is formed by photolithography, the transfer electrode 8 is formed by etching (FIG. 9C).
Finally, the resist pattern 14 is removed (not shown).
[0009]
[Patent Document 1]
JP-A-5-315584 [Patent Document 2]
JP 2001-94090 A
[Problems to be solved by the invention]
However, as shown in FIG. 9B, when a polysilicon film serving as the transfer electrode 8 is formed, a step due to the transfer electrode 7 is reflected. As shown in FIG. 9C, the thickness of the resist film greatly varies locally. For this reason, there has been a problem that it is difficult to precisely and uniformly process the transfer electrode 8 of the second layer.
[0011]
Further, when the unit cell is miniaturized, a step due to the transfer electrode 7 with respect to the size of the unit cell becomes large, and the variation in the film thickness of the resist pattern 14 becomes relatively large. For this reason, a defective overlap region of the transfer electrodes 7 and 8 or a variation in the shape of each unit cell occurs. Further, when a solid-state imaging device having such a processing defect is used, a defect such as image unevenness occurs.
In order to reduce a step caused by three or more transfer electrodes, for example, it is conceivable to reduce the number of transfer electrode layers. However, since the minimum number of transfer electrodes is two, it is not possible to eliminate a step due to the first-layer transfer electrode when forming the second-layer transfer electrode.
[0012]
In Patent Literatures 1 and 2, a transfer electrode is not formed on a semiconductor layer, and the transfer electrode is embedded in the semiconductor layer to eliminate a step due to the transfer electrode.
FIG. 10 is a sectional view of a unit cell provided in another conventional solid-state imaging device. FIG. 11 and FIG. 12 are explanatory diagrams of the procedure for forming the transfer electrodes 7 and 8 provided in the solid-state imaging device.
The unit cell of the solid-state imaging device shown in FIG. 10 is different from the unit cell of the solid-state imaging device shown in FIG. 7 in that a trench (groove) is formed in the P-type well 2 and a transfer gate portion which is a bottom surface of the trench. A first-layer transfer electrode 7 and a second-layer transfer electrode 8 are formed on the upper surface 4 and the upper surface of the N-type well 5 via an oxide film 6. In this case, the upper surface of the transfer electrode 8 and the upper surface of the photodiode unit 30 are flat surfaces having substantially the same height, and the upper surfaces of the transfer electrodes 7 and 8 are covered with the light shielding film 11.
[0013]
When such transfer electrodes 7 and 8 are formed, first, a resist pattern 14 serving as a mask is formed on the semiconductor layer 20 by photolithography (FIG. 11A).
Next, the first trenches 21, 21,... Are formed by etching (FIG. 11B), the resist pattern 14 is removed, and the bottom surfaces of the first trenches 21, 21,. A polysilicon film serving as the transfer electrode 7 is formed on the semiconductor layer 20 (FIG. 11C).
Next, the polysilicon film having a step due to the trench is flattened by etching back (the hatched portion in FIG. 11C is removed) (FIG. 11D).
[0014]
Next, in order to perform patterning, a resist pattern 14 serving as a mask is formed by photolithography on the planarized polysilicon film (FIG. 12A).
Next, transfer electrodes 7, 7,... Are formed by etching. At this time, the transfer electrode 7 has a convex cross section, and the second trenches 22, 22,... Are formed so as to be sandwiched between the transfer electrodes 7 (FIG. 12 ( b)).
Next, the resist pattern 14 is removed, and a polysilicon film to be the transfer electrode 8 is formed on the semiconductor layer 20 including the bottom surfaces of the second trenches 22, 22,... And the transfer electrodes 7, 7,. FIG. 12 (c).
[0015]
Finally, the unevenness of the polysilicon film is flattened by etching back (the hatched portion in FIG. 12C is removed). At this time, the transfer electrodes 8, 8,... Are formed by flattening so that the upper surface of the polysilicon film and the uppermost surfaces of the transfer electrodes 7, 7,. )).
In the solid-state imaging device described above, when forming the transfer electrodes 7 and 8, it is necessary to perform photolithography, etching (trench formation), and etch-back twice each.
[0016]
FIG. 13 is a sectional view of a unit cell provided in still another conventional solid-state imaging device.
The unit cell of the solid-state imaging device shown in FIG. 13 is different from the unit cell of the solid-state imaging device shown in FIG. 7 or 10 (the transfer electrodes 7 and 8 are substantially parallel to the N-type silicon substrate 1). , 8 are arranged in the vertical direction (substantially perpendicular to the N-type silicon substrate 1).
In the unit cell of the solid-state imaging device illustrated in FIG. 13, a small opening trench that is not adjacent to the transfer gate unit 4 and is adjacent to the N-type well 5 of the vertical CCD unit 50 is formed. A channel stopper 9 is provided below the small opening trench and adjacent to the small opening trench on the side opposite to the N-type well 5.
[0017]
Further, a transfer electrode 7 and a transfer electrode 8 are formed vertically in the small opening trench via an oxide film 6. In this case, the upper end surfaces of the transfer electrodes 7 and 8 and the upper surface of the photodiode portion 30 are flat surfaces having substantially the same height, and the upper end surfaces of the transfer electrodes 7 and 8 and the upper surface of the N-type well 5 are Is covering.
In the solid-state imaging device described above, it is difficult to form the transfer electrodes 7 and 8.
[0018]
The present invention has been made in view of such circumstances, and, among a plurality of transfer electrodes, some transfer electrodes are buried in another conductive type well, and another transfer electrode is stacked on the other conductive type well. Accordingly, an object of the present invention is to provide a solid-state imaging device that can easily improve the processing accuracy and uniformity of each transfer electrode.
[0019]
[Means for Solving the Problems]
The solid-state imaging device according to the present invention is a photodiode part that photoelectrically converts and stores charges in a well of another conductivity type provided in a semiconductor substrate of one conductivity type, a vertical CCD part in which charges from the photodiode part are transferred, In the solid-state imaging device including a transfer gate portion which is a path of a charge to the vertical CCD portion, a plurality of transfer electrodes formed on an upper surface of the vertical CCD portion and the transfer gate portion with an insulating film interposed therebetween, Wherein the transfer electrode located on the one conductivity type semiconductor substrate side is buried in the other conductivity type well.
[0020]
The solid-state imaging device according to the present invention is characterized in that an upper surface of the transfer electrode is located on substantially the same plane as an upper surface of the photodiode section.
[0021]
The solid-state imaging device according to the present invention includes a flattening film formed on the upper surface side of the one conductivity type semiconductor substrate, a color filter layer formed on the flattening film, and a color filter layer formed on the color filter layer. And a micro lens.
[0022]
According to the present invention, for example, when a transfer electrode of two layers is formed, the transfer electrode of the first layer is buried in a well of another conductivity type. The step due to the transfer electrode is reduced.
Further, when the upper surface of the first-layer transfer electrode is located on substantially the same plane as the upper surface of the photodiode portion, the step due to the first-layer transfer electrode is eliminated.
Further, the trench is formed only once when the first-layer transfer electrode is buried in the other conductivity type well, and the etch-back only needs to be performed once before forming the second-layer transfer electrode. The transfer electrode forming process is simpler than in the case where the transfer electrodes of all the layers are buried in the other conductivity type wells.
[0023]
In such a solid-state imaging device, since a step due to the lower transfer electrode does not hinder the formation of the upper transfer electrode, a processing defect such as a defective overlap region of the transfer electrode or a variation in the shape of each unit cell. Has been prevented. That is, in such a solid-state imaging device, the processing accuracy of the transfer electrodes is improved, and the uniformity is improved by preventing the variation of the shape of each transfer electrode.
Further, when such a solid-state imaging device includes a color filter layer, a color image can be detected by the solid-state imaging device with improved processing accuracy and uniformity of the transfer electrode.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments.
Embodiment 1.
FIG. 1 is a plan view of the solid-state imaging device according to Embodiment 1 of the present invention, and shows an arrangement of unit cells included in the solid-state imaging device.
In the figure, reference numeral 30 denotes a photodiode unit, and the photodiode units 30, 30,... Are arranged in a matrix. Also, a vertical CCD unit 50 long in the column direction of the photodiode units 30, 30,... Is arranged for each column of the photodiode units 30, 30,. Further, a horizontal CCD section 15 that is long in the row direction of the photodiode sections 30, 30,... Is arranged on one end side of the vertical CCD sections 50, 50,. Have been.
[0025]
FIG. 2 is a sectional view of a unit cell included in the solid-state imaging device, and is a sectional view taken along line III-III in FIG. FIG. 3 is a cross-sectional view of the transfer electrodes 7 and 8 included in the solid-state imaging device, and is a cross-sectional view taken along line IV-IV of FIG. Illustration of the lens 13 is omitted.
In FIG. 1, reference numeral 1 denotes an N-type silicon substrate which is a semiconductor substrate of one conductivity type, and a P-type well 2 which is a well of another conductivity type is provided on the upper surface side in the N-type silicon substrate 1.
[0026]
In the P-type well 2, the photodiode unit 30, the vertical CCD unit 50, and the space between the photodiode unit 30 and the vertical CCD unit 50 are sandwiched between the channel stopper units 9, 9 separating each unit cell. An intervening transfer gate section 4 is provided side by side. In this case, an N-type region 3 which is a part of the photodiode unit 30 is selectively provided in the P-type well 2, and the vertical CCD unit 50 is sandwiched by the transfer gate unit 4 adjacent to the N-type region 3. Is provided as an N-type well 5. The channel stopper section 9 is adjacent to the vertical CCD section 50 of one unit cell and a trench (or photodiode section 30) described later, and further has the photodiode section 30 (or vertical CCD section 50 and the trench section) of another unit cell. ).
On the upper surface of the N-type region 3, that is, on the upper part of the photodiode unit 30, a surface P + layer 10 for stabilizing the surface of the photodiode unit 30 is provided. The top surface of the surface P + layer 10, the channel stopper 9, and the transfer electrode 7 described later are covered with the oxide film 6.
[0027]
Further, a trench is formed in the P-type well 2 so as to be sandwiched between the photodiode portion 30 of one unit cell and the channel stopper 9 not adjacent to the photodiode portion 30. Has an upper surface of the transfer gate unit 4 and the N-type well 5 of the vertical CCD unit 50 on a part of the bottom surface thereof. The bottom and side surfaces in the trench are covered with an oxide film 6, and a transfer electrode 7 made of, for example, polysilicon is disposed inside the trench on the oxide film 6. The upper surface of the transfer electrode 7 is substantially at the same height as the upper surface of the photodiode unit 30.
In this way, the transfer electrode 7 of the first layer (that is, located on the N-type silicon substrate 1 side among the transfer electrodes 7 and 8 of the plurality of layers) is transferred via the oxide film 6 which is an insulating film. It is formed on the upper surface of the gate part 4 and the N-type well 5 of the vertical CCD part 50 and is buried in the P-type well 2. Further, the upper surface of the transfer electrode 7 and the upper surface of the photodiode unit 30 are located on substantially the same plane.
[0028]
A second-layer transfer electrode 8 made of, for example, polysilicon is formed on the transfer electrode 7 with an oxide film 6 interposed therebetween. That is, the transfer electrodes 7 and 8 are formed on the upper surfaces of the transfer gate unit 4 and the N-type well 5 of the vertical CCD unit 50 via the oxide film 6 which is an insulating film. It is stacked on the upper surface side of the mold well 2.
Further, the light-shielding film 11 made of, for example, W covers the upper and side surfaces of the transfer electrodes 7 and 8 via the oxide film 6.
[0029]
Further, the upper surface side of the N-type silicon substrate 1, that is, on the light shielding film 11 and the oxide film 6, is covered with a flattening film 12 for flattening unevenness due to the transfer electrode 8, and furthermore, the flattening film 12 and the oxide film On the upper side of the photodiode section 30 through the microlens 6, a microlens 13 which is a condenser lens is formed.
Also, as shown in FIG. 3, transfer electrodes 7, 7,... (Or transfer electrodes 8, 8,...) Are provided between transfer electrodes 7, 7,. (Or intervals 80, 80,...) For electrically interrupting are provided, and an overlap in which the transfer electrode 8 is stacked on the transfer electrode 7 (via the oxide film 6). An area 78 is provided.
[0030]
As shown by the arrow in FIG. 1, the electric charge that has been photoelectrically converted by the photodiode unit 30 and accumulated is collected by the vertical CCD unit 50 via the transfer gate unit 4. At this time, by applying a pulse voltage to the transfer electrodes 7 and 8 alternately, the charges collected in the vertical CCD unit 50 are sequentially transferred to the horizontal CCD unit 15 and further horizontally transferred to the output unit 16. The output section 16 converts the signal voltage into a signal voltage and outputs the signal voltage. As described above, the solid-state imaging device detects an image.
[0031]
4 and 5 are explanatory diagrams of a procedure for forming a solid-state imaging device.
First, a resist pattern serving as a mask is formed on an N-type silicon substrate 1 by photolithography, and a P-type well 2 is formed by ion implantation. Next, using the resist pattern as a mask, the P-type well 2 is etched to form a trench having a depth of several thousand Å at a position corresponding to the first-layer transfer electrode 7 (FIG. 4A). This depth is the thickness of the oxide film 6 formed in the transfer electrode 7 and the trench.
Next, an oxide film 6 is formed on the P-type well 2 including the bottom and side surfaces of the trench, and the N-type well 5 of the vertical CCD unit 50 and the channel stopper are formed by ion implantation using a resist pattern as a mask. 9 and the transfer gate unit 4 are provided, respectively (FIG. 4B).
If the required implantation profile can be achieved, the trench and the oxide film 6 are formed after the ion implantation, so that a reduction in resist pattern processing accuracy at the time of ion implantation due to a trench step can be avoided.
[0032]
Next, after using a transfer electrode material (for example, polysilicon) to be the transfer electrode 7 and forming a polysilicon film on the upper surface of the P-type well 2 including the bottom surface of the trench, the upper surface of the transfer electrode 7 is Perform etch-back so that the height is approximately the same as. That is, the transfer electrode 7 is formed by removing the polysilicon film and the oxide film outside the trench by etching and flattening (FIG. 4C).
Next, an oxide film 6 is formed on the transfer electrode 7 and the upper surface of the P-type well 2, and a second-layer transfer electrode 8 is formed on the upper surface of the transfer electrode 7 by photoetching via the oxide film 6 (FIG. 5). (A)). That is, a polysilicon film to be the transfer electrode 8 is formed on the formed oxide film 6, a resist pattern is formed on the formed polysilicon film, and the transfer electrode 8 is formed by etching. Form.
[0033]
Further, the N-type region 3 and the surface P + layer 10 of the photodiode section 30 are sequentially formed by ion implantation, and then an oxide film 6 covering the upper and side surfaces of the transfer electrode 8 is formed. As a result, a light-shielding film 11 that covers the upper and side surfaces of the transfer electrodes 7 and 8 via the oxide film 6 is formed (FIG. 5B).
Finally, a solid-state imaging device as shown in FIG. 2 is formed by forming the flattening film 12 and the microlenses 13.
[0034]
In the solid-state imaging device as described above, as shown in FIG. 4C, the upper surface of the unit cell is flat before the formation of the polysilicon film to be the transfer electrode 8 of the second layer. That is, there is no step due to the transfer electrode 7. Therefore, the upper surface of the formed polysilicon film becomes flat, and the thickness of the resist film becomes constant within the upper surface of the unit cell when the photoresist is applied.
Further, each of the trench forming step and the etch back step is performed only once, so that the step of forming the transfer electrodes 7 and 8 is simple.
[0035]
In the present embodiment, a solid-state imaging device in which one transfer electrode is buried among two transfer electrodes is illustrated, but transfer electrodes of N layers (N is a natural number of 3 or more) are illustrated. Among them, a solid-state imaging device in which one or more transfer electrodes of less than N layers are embedded may be used. In this case, the transfer electrode forming process is simpler than in the solid-state imaging device in which all N layers are embedded, and in comparison with the solid-state imaging device in which all N layers are stacked on the upper surface side of the P-type well 2. This improves the processing accuracy and uniformity.
[0036]
Embodiment 2.
FIG. 6 is a sectional view of a unit cell included in the solid-state imaging device according to Embodiment 2 of the present invention.
In the present embodiment, the color filter layer 17 is formed on the flattening film 12, and the microlenses 13 are formed on the color filter layer 17 above the photodiode section 30.
In addition, the same reference numerals are given to portions corresponding to the first embodiment, and description thereof will be omitted.
[0037]
Like the solid-state imaging device according to the first embodiment, the solid-state imaging device described above has no step due to the transfer electrode 7 before the formation of the polysilicon film to be the transfer electrode 8 of the second layer. The upper surface of the formed polysilicon film becomes flat, and the thickness of the resist film during the application of the photoresist becomes constant within the upper surface of the unit cell. Further, the process of forming the transfer electrodes 7 and 8 is simple. Further, such a solid-state imaging device detects a color image.
[0038]
【The invention's effect】
According to the solid-state imaging device of the present invention, by embedding the lower layer transfer electrode in the other conductive type well among the plurality of layers of transfer electrodes, the processing accuracy of the upper layer transfer electrode is dramatically improved, and Since the uniformity of the electrodes is improved, it is possible to prevent processing defects such as overlap failure of the transfer electrodes or variation in the shape of each unit cell, even when the unit cells are miniaturized. That is, such a solid-state imaging device can secure a matching margin between transfer electrodes and can reduce a performance difference / transfer difference between unit cells.
[0039]
Further, when such a solid-state imaging device is used, it is possible to prevent a defect such as image unevenness. In addition, a complicated process is not required when forming a solid-state imaging device.
Further, when such a solid-state imaging device includes a color filter layer, the present invention has excellent effects, such as a color image can be detected by a solid-state imaging device with improved processing accuracy and uniformity of a transfer electrode. .
[Brief description of the drawings]
FIG. 1 is a plan view of a solid-state imaging device according to Embodiment 1 of the present invention.
FIG. 2 is a sectional view of a unit cell included in the solid-state imaging device according to Embodiment 1 of the present invention;
FIG. 3 is a sectional view of a transfer electrode included in the solid-state imaging device according to the first embodiment of the present invention;
FIG. 4 is an explanatory diagram of a procedure for forming the solid-state imaging device according to the first embodiment of the present invention;
FIG. 5 is an explanatory diagram of a procedure for forming the solid-state imaging device according to the first embodiment of the present invention;
FIG. 6 is a sectional view of a unit cell included in a solid-state imaging device according to a second embodiment of the present invention;
FIG. 7 is a cross-sectional view of a unit cell included in a conventional solid-state imaging device.
FIG. 8 is a plan view of a transfer electrode included in a conventional solid-state imaging device.
FIG. 9 is an explanatory diagram of a procedure for forming a transfer electrode included in a conventional solid-state imaging device.
FIG. 10 is a sectional view of a unit cell provided in another conventional solid-state imaging device.
FIG. 11 is an explanatory diagram of a procedure for forming a transfer electrode included in another conventional solid-state imaging device.
FIG. 12 is an explanatory diagram of a procedure for forming a transfer electrode included in another conventional solid-state imaging device.
FIG. 13 is a sectional view of a unit cell provided in still another conventional solid-state imaging device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 N-type silicon substrate 2 P-type well 30 Photodiode part 4 Transfer gate part 50 Vertical CCD part 6 Oxide film 7, 8 Transfer electrode 12 Flattening film 13 Micro lens 17 Color filter layer

Claims (3)

A photodiode portion that photoelectrically converts and accumulates charges in a well of another conductivity type provided in a semiconductor substrate of one conductivity type, a vertical CCD portion to which charges from the photodiode portion are transferred, and a transfer of charges to the vertical CCD portion. In a solid-state imaging device including a transfer gate portion that is a passage, a vertical CCD portion, and a plurality of layers of transfer electrodes formed on an upper surface of the transfer gate portion via an insulating film,
A solid-state imaging device, wherein a transfer electrode located on the one conductivity type semiconductor substrate side among the plurality of layers of transfer electrodes is embedded in the other conductivity type well. 2. The solid-state imaging device according to claim 1, wherein an upper surface of the transfer electrode is located on substantially the same plane as an upper surface of the photodiode unit. 3. A flattening film formed on the upper surface side of the one conductivity type semiconductor substrate, a color filter layer formed on the flattening film, and a microlens formed on the color filter layer. The solid-state imaging device according to claim 1.

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