JPH06291295A - Solid-state image sensor - Google Patents

Abstract

PURPOSE:To provide a miniaturized solid-state image sensor having a large photoelectric storage section by forming a diffused layer that overlaps an adjacent transfer electrode. CONSTITUTION:In a solid-state image sensor, an n-type diffused layer 103 in a photoelectric storage section is formed to overlap a transfer electrode 101 in a vertical CCD section, rather than in self-alignment. On the other hand, the n-type diffused layer 103 may be self-aligned with an n-type diffused layer 104 in the vertical CCD section. As a result, it is possible to enlarge the aperture of the photoelectric storage section in the event of device miniaturization. Since the photoelectric storage section is formed relatively large even in a miniaturized device, a solid-state image sensor of high sensitivity can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device having a reduced size, and more particularly to a solid-state image pickup device having high sensitivity and a solid-state image pickup device having good smear resistance.

[0002]

[Prior art]

 <First Conventional Technique>

A solid-state image pickup device is a device used as an image pickup element in a video camera, an electronic still camera, or the like. This device converts input light into a signal charge, stores it in a photoelectric conversion storage unit, transfers it by a charge-coupled device (hereinafter abbreviated as CCD), and outputs it.

In recent years, in order to reduce the size and weight of the camera, it is required to reduce the size of the solid-state image pickup device. In the future, the size of the photoelectric conversion storage unit will be 5 μm from the current 9 μm cell.
There is a demand for further miniaturization into cells of m or less.

However, in the conventional technique, since the photoelectric conversion storage section and the vertical transfer CCD are formed by separate lithography processes, there is a drawback that the area of the photoelectric conversion storage section cannot be increased. For this reason, as miniaturization progresses, the sensitivity decreases, and there arises a problem that the specifications cannot be satisfied.

FIG. 7 shows a photoelectric conversion storage unit and a vertical transfer CCD.
FIG. 6 is a schematic cross-sectional view showing an example of a conventional pixel portion in which and are formed in separate lithography steps. In this example, the vertical transfer electrode 101 and the n-type diffusion region 103 of the photoelectric conversion storage unit are formed in a self-aligned process. Therefore, the transfer electrode 101 of the vertical transfer CCD and the photoelectric conversion storage unit 103
It does not overlap with, nor is it separated. Further, in this case, the photoelectric conversion storage unit 103 and the n-type diffusion region 104 of the vertical transfer CCD cannot necessarily be formed in a self-aligned process.

Therefore, considering the misalignment in the lithography process, it is necessary to increase the distance between the photoelectric conversion storage portion and the vertical transfer CCD, and as a result, it is difficult to increase the aperture ratio.

Here, the reason why the n-type diffusion region 103 of the photoelectric conversion storage portion and the vertical transfer electrode 101 are formed by self-alignment in the prior art will be described with reference to FIG. That is, before, as shown in FIG. 8, the p-type impurity diffusion layer was not formed on the photoelectric conversion storage portion. In this case, assuming that the n-type diffusion region 103 of the photoelectric conversion storage unit and the vertical transfer electrode 101 are not self-aligned,
There is a possibility that the n-type diffusion region 103 of the photoelectric conversion storage unit and the vertical transfer electrode 101 may overlap due to misalignment in the lithography process. In this case, capacitive coupling occurs between the n-type diffusion region 103 of the photoelectric conversion storage unit and the vertical transfer electrode 101, which makes complete reading difficult during charge reading. Therefore, in order to avoid the influence of the capacitive coupling, as described above, the n-type diffusion region 103 of the photoelectric conversion storage unit and the vertical transfer electrode 101 are formed in self-alignment to avoid the generation of the coupling capacitance. Was. In recent years, as shown in FIG. 7, a structure in which a p-type impurity diffusion layer is formed above the photoelectric conversion storage part has been introduced. However, the photoelectric conversion like the conventional one has been adopted because of the advantage of following the manufacturing process up to that point. The n-type diffusion region 103 of the storage portion and the vertical transfer electrode 10
1 and 1 were formed by self-alignment. <Second conventional technology>

In recent years, semiconductor devices have been highly integrated, and are composed of pixel cells each including a vertical charge transfer electrode (hereinafter abbreviated as VCCD) and a photodiode (hereinafter abbreviated as PD). Also in the solid-state image pickup device, the research for reducing the pixel cell size is progressing. When such a pixel cell is reduced in size, deterioration of image characteristics due to a decrease in the aperture area of the PD and a decrease in the transfer charge amount due to the miniaturization of the VCCD becomes a problem.

FIG. 13 shows an example of a sectional view of a pixel cell portion of a conventional solid-state image pickup device. In this pixel cell portion, a diffusion layer (not shown) for forming a photodiode and a vertical transfer channel (not shown) are formed on a semiconductor substrate 241, and a gate insulating film 242 is formed thereon. Then, in the VCCD area, a relatively thick thickness H (eg,
A gate electrode 243 of 200 to 400 nm), an interlayer insulating film 244 for electrically insulating the gate electrode 243 and the light shielding layer 245, and a light shielding layer 245.
Is formed and formed. Here, in the PD portion, the distance between the light shielding layer 245 and the substrate 241 with the interlayer insulating film 244 and the gate insulating film 242 sandwiched therebetween is d.

FIG. 12 shows the relationship between the film thickness d between the light shielding layer and the substrate and the smear. The smear may be suppressed to -80 dB or less, and for that purpose, the light shielding layer-substrate distance d is 600 n.
It is known that it should be m or less. That is, the distance d between the light-shielding layer and the substrate should satisfy the formula (1).

However, in the conventional solid-state image pickup device, the inactive region 24 for satisfying the formula (1) is considered in consideration of misalignment.
6 is required, it is difficult to increase the aperture ratio of the PD portion, and it is impossible to reduce the pixel cell.

Further, the light-shielding layer 245 in the pixel cell portion is shown in FIG.
As shown in FIG. 3, it is formed on the thick gate electrode 243 so as to be dropped into the substrate 241 via the interlayer insulating film 244. Therefore, when the step H corresponding to the gate electrode between the VCCD section and the PD section is large, there is a problem that the light-shielding layer 245 is broken and the smear resistance is deteriorated.

[0014]

In the above-mentioned conventional solid-state image pickup device, the photoelectric conversion storage portion and the vertical transfer CCD are formed in separate steps. Therefore, when misalignment during exposure is considered, There is a problem that it is difficult to realize high sensitivity when the miniaturization is advanced because the aperture ratio cannot be designed large. The present invention has been made in view of the above circumstances, and an object thereof is to provide a solid-state imaging device having a small area and high sensitivity.

On the other hand, in the conventional solid-state image pickup device, it is necessary to provide an inactive region in order to secure a necessary smear characteristic, it is difficult to increase the aperture ratio of the PD portion, and it is impossible to reduce the pixel cell. there were. Further, there is a problem that a large step due to the gate electrode causes step breakage of the light shielding layer and deteriorates smear resistance. Another object of the present invention is to provide a solid-state imaging device that includes a reduced pixel cell and a PD having a large aperture ratio and that has a good anti-smear characteristic.

[0016]

[Means for Solving the Problems] In order to solve the above problems and achieve the object, the following measures were taken.

(1) In the solid-state image pickup device according to the present invention, a plurality of photoelectric conversion storage units arranged two-dimensionally on a semiconductor substrate, which are signals for storing signal charges generated by incident light. A photoelectric conversion storage unit having an impurity diffusion layer forming a charge storage diode, a plurality of vertical transfer CCDs having transfer electrodes for reading and transmitting charges stored in the impurity diffusion layer of the photoelectric conversion storage unit, and the vertical transfer CC.
A solid-state image pickup device comprising a horizontal transfer CCD which receives a D signal and horizontally transfers it, wherein the impurity diffusion layer and a transfer electrode adjacent thereto are formed to overlap each other. .

(2) In the solid-state image pickup device according to the present invention, a photodiode formed on the surface of the semiconductor substrate for converting incident light into an electric signal to accumulate charges, and a gate insulation on the semiconductor substrate. A vertical transfer electrode, which is formed through a film and constitutes a charge-coupled device for taking out the electric charge accumulated in the photodiode to the outside of the device, and a whole device including the photodiode and the vertical transfer electrode. In the solid-state imaging device, the interlayer insulating film is provided, and a light-shielding layer is provided on the interlayer insulating film so as to cover the vertical transfer electrodes and prevents light from entering the vertical transfer electrodes. , The distance d between the light shielding layer and the semiconductor substrate with the interlayer insulating film, the vertical transfer electrode, and the gate insulating film sandwiched is d ≦ 600 nm (1) And wherein the Succoth.

[0019]

As a result of taking the above-mentioned means, the following effects occur.

(1) The impurity diffusion layer and the transfer electrode adjacent thereto are formed to overlap each other. This allows
Even when miniaturization is advanced, the photoelectric conversion storage unit and the vertical transfer C
By forming the CD in a self-aligned process, it is possible to increase the area of the photoelectric conversion storage portion. Therefore, the aperture ratio can be increased even if the area of the photoelectric conversion storage unit is reduced due to miniaturization, and thus a solid-state imaging device having high sensitivity can be provided.

(2) The vertical transfer electrodes are thinned so that the distance d between the light shielding layer and the semiconductor substrate sandwiching the gate electrode is 600 n.
m or less. Therefore, since the distance between the light shielding layer and the substrate satisfies the formula (1) everywhere where the active region exists,
The effect of blocking the light that tries to leak in works sufficiently, and the smear level can be made -80 dB or less.

Therefore, it is not necessary to provide an inactive region as in the conventional image pickup device, and the aperture ratio of the PD can be increased accordingly. Furthermore, it is possible to widen the margin for misalignment.

Further, since the light shielding layer can be formed with a uniform thickness by thinning the gate electrode, it is possible to prevent breakage of the light shielding layer as in the conventional case, and improve smear resistance. Can be expected. Therefore, by improving the smear resistance and expanding the design margin, it is possible to increase the density of the image sensor by miniaturizing the pixel cells.

[0024]

Embodiments will be described below with reference to the drawings. The same parts are designated by the same reference numerals and detailed description thereof will be omitted. <First, Second and Third Embodiments>

FIG. 1 is a schematic sectional view of a pixel portion of a solid-state image pickup device according to the first embodiment of the present invention. In this pixel portion, the n-type impurity diffusion layer 104 of the vertical CCD portion and the n-type impurity diffusion layer 103 of the photoelectric conversion storage portion are formed on the n-type semiconductor substrate 106, and further, P is formed on the surface portion of the diffusion region 103. A type diffusion region 102 is formed, and then a transfer electrode 101 of the vertical CCD section is formed via a gate insulating film 107.

At this time, in the present invention, the n-type impurity diffusion layer 103 of the photoelectric conversion storage section and the transfer electrode 101 of the vertical CCD section are not formed in a self-aligned process, but the n-type impurity of the photoelectric conversion storage section is not formed. The diffusion layer 103 and the transfer electrode 101 of the vertical CCD section are formed to overlap each other.

As a result, the n-type impurity diffusion layer 103 of the photoelectric conversion storage section and the n-type impurity diffusion layer 104 of the vertical CCD section are provided.
Can be formed in a self-aligned process.
Therefore, it is possible to increase the aperture ratio of the photoelectric conversion storage unit even when miniaturization is advanced. As a result, the area of the photoelectric conversion storage section can be made larger even if the element area becomes smaller due to miniaturization, and thus a solid-state imaging device having high sensitivity can be realized.

Here, in the present invention, n of the photoelectric conversion storage unit is used.
The point that the type diffusion region 103 and the vertical transfer electrode 101 are not formed by self-alignment will be described. In FIG.
The n-type diffusion region 103 of the photoelectric conversion storage unit is the P-type diffusion region 1
It is covered with 02. Therefore, for example, the P-type diffusion region 1
If 02 is grounded, even if a voltage is applied to the vertical transfer electrode 101 during charge reading, the p-type impurity diffusion layer 1
Since it is shielded by 02, no coupling capacitance as in the conventional case is generated, and the potential in the n-type diffusion region 103 below the vertical transfer electrode hardly changes. Therefore, complete reading does not become difficult unlike the conventional case. Therefore, the vertical transfer electrode 101 and the n-type diffusion region 10 of the photoelectric conversion storage unit
There is no adverse effect even if 3 and 3 overlap. Focusing on this point, the present inventors have adopted a structure in which the photoelectric conversion storage portion and the vertical transfer electrode are not formed by self-alignment as in the conventional technique but are formed so as to overlap each other.

FIG. 2 is a diagram showing an example of a process flow for making the device of FIG. First, FIG.
As shown in (a), the oxide film 108 is formed on the p-well 105 on the n-type substrate 106, and after the SiN 109 is formed, the SiN film 109 in the photoelectric conversion storage portion and the vertical CCD portion is etched. Next, as shown in FIG. 2B, a resist 110 is applied, the resist 110 in the vertical transfer CCD portion is etched, and the remaining resist 110 and the SiN film 109 are etched.
Using as a mask, ions are implanted into the vertical transfer CCD section to form the n-type impurity diffusion layer 104. Furthermore, FIG.
As shown in (c), after the resist 110 is peeled off, the resist 111 is applied again, this time the resist in the photoelectric conversion storage portion is etched, and ions are implanted into the photoelectric conversion storage portion to form an n-type impurity diffusion layer. 103 and P-type diffusion region 102
Are sequentially formed. Through the above process, the photoelectric conversion storage unit and the vertical transfer CCD can be formed in a self-aligned process.

FIG. 3 is a diagram showing another example of the process flow for making the device of FIG. As shown in FIG. 3A, the oxide film 1 is formed on the p-well 105 on the n-type substrate 106.
08, then SiN109 and then resist 1
10 is applied, and the resist 110 and the SiN film 109 in the photoelectric conversion storage part and the vertical transfer CCD part are etched. Next, as shown in FIG. 3B, the resist 110 and the S
Ions are implanted into the vertical transfer CCD section and the photoelectric conversion storage section using the iN film 109 as a mask to simultaneously form the n-type impurity diffusion layer 104 and the n-type impurity diffusion layer 103.
Further, as shown in FIG. 3C, after removing the resist 110, the resist 111 is applied again, the resist in the photoelectric conversion storage portion is etched, and ions are implanted into the photoelectric conversion storage portion to perform P-type diffusion. A region 102 is formed. In this case, the impurities of the n-type impurity diffusion layer 103 of the photoelectric conversion storage unit are implanted by ion implantation twice.

Through the above steps, the photoelectric conversion storage section and the vertical transfer CCD can be formed in self-alignment. This process flow is particularly effective when the impurity concentration of the vertical transfer CCD unit is lower than the impurity concentration of the photoelectric conversion storage unit, and the number of steps can be reduced as compared with the process flow described in FIG.

FIG. 4 is a diagram showing yet another example of the process flow for producing the device of FIG. Figure 4
As shown in (a), an oxide film 108 is formed on the p-well 105 on the n-type substrate 106, a resist 110 is applied, and the resist of the photoelectric conversion storage part and the vertical transfer CCD part is etched. Next, as shown in FIG. 4B, ion implantation is performed on the vertical transfer CCD and the photoelectric conversion storage unit using the resist 110 as a mask as it is. Further, as shown in FIG.
The second layer resist 11 while leaving the resist 110
2 is applied, the second layer resist of the photoelectric conversion storage portion is etched, and ions are implanted into the photoelectric conversion storage portion.

Through the above steps, the photoelectric conversion storage section and the vertical transfer CCD can be formed in self-alignment. Similar to the process flow described with reference to FIG. 3, this process flow is particularly effective when the impurity concentration of the vertical transfer CCD is lower than the impurity concentration of the photoelectric conversion storage unit. Also, the number of steps can be further reduced by the SiN film step.

FIG. 5 is a schematic sectional view of a pixel portion of a solid-state image pickup device according to the second embodiment of the present invention. In this pixel portion, the n-type impurity diffusion layer 104 of the vertical CCD portion and the n-type impurity diffusion layer 115 of the photoelectric conversion storage portion are formed on the n-type semiconductor substrate 106, and P is formed on the surface portion of the diffusion region 115. A type diffusion region 114 is formed, and then a transfer electrode 101 of the vertical CCD section is formed via a gate insulating film 107.

Also in this embodiment, n of the photoelectric conversion storage unit is
-Type impurity diffusion layer 115 and transfer electrode 101 of vertical CCD section
Is not formed in a self-aligned process, but the n-type impurity diffusion layer 115 of the photoelectric conversion storage portion and the transfer electrode 101 of the vertical CCD portion are formed separately. Therefore, it becomes possible to form the n-type impurity diffusion layer 115 of the photoelectric conversion storage section and the n-type impurity diffusion layer 104 of the vertical CCD section in a self-aligned process.

Therefore, since the photoelectric conversion storage portion and the transfer electrode are not overlapped, it is effective when the aperture ratio can be increased and the sensitivity specifications are strict. In particular, it is effective in a single-layer metal electrode CCD that also serves as a light shielding layer (not shown) and a CCD transfer electrode.

FIG. 6 is a schematic sectional view of a pixel portion of a solid-state image pickup device according to the third embodiment of the present invention. In this pixel portion, the n-type impurity diffusion layer 104 of the vertical CCD portion and the n-type impurity diffusion layer 116 of the photoelectric conversion storage portion are formed on the n-type semiconductor substrate 106, and the vertical CCD is provided via the gate insulating film 107. And a transfer electrode 101 is formed.

Also in this embodiment, n of the photoelectric conversion storage unit is
-Type impurity diffusion layer 116 and transfer electrode 101 of vertical CCD section
Is not formed in a self-aligned process, but the n-type impurity diffusion layer 116 of the photoelectric conversion storage portion and the transfer electrode 101 of the vertical CCD portion are formed separately. Therefore, it is possible to form the n-type impurity diffusion layer 116 of the photoelectric conversion storage section and the n-type impurity diffusion layer 104 of the vertical CCD section in a self-aligned process.

Thereby, the impurity distribution in the substrate depth direction of the n-type impurity diffusion layer 116 of the photoelectric conversion storage portion and the impurity distribution in the substrate depth direction of the n-type impurity diffusion layer 104 forming the channel of the vertical transfer CCD. Can be the same. Here, if the photoelectric conversion layer and the CCD have the same concentration profile, it is effective because the number of ion implantation steps is reduced once. <Fourth Embodiment>

FIG. 9 is a plan view of a pixel cell portion of a solid-state image pickup device according to the fourth embodiment of the present invention, and FIG.
-A 'line sectional drawing is shown. As shown in the figure, one pixel cell includes a PD portion having an opening and a gate electrode 223.
It is composed of a VCCD having In this pixel cell, a diffusion layer (not shown) for forming a photodiode and a vertical transfer channel (not shown) are formed on a semiconductor substrate 221 and a gate insulating film 222 is formed thereon. Then, a thin film gate electrode (vertical transfer electrode) 223 is formed in the VCCD region, and the gate electrode 223 and the light shielding layer 2 are formed.
25, an interlayer insulating film 224 is formed to electrically insulate the insulating layer 25 from the insulating layer 225, and then a light shielding layer 225 is formed.

In the manufacturing process of the present image pickup device, for example, the gate insulating film 222 on the silicon substrate 221 is formed with a thermal oxide film of about 70 nm, and the gate electrode 223 is formed of Ti.
Is deposited by sputtering to a thickness of 70 nm, and is cut out to form a pattern as shown in FIG. 9 by anisotropic etching. The interlayer insulating film 224 is deposited by CVD to 400 nm, and the light shielding layer 225 is deposited by sputtering 800 nm of Al.
The photodiode part may be formed by opening.

Here, in the VCCD portion, the interlayer insulating film 22 is formed.
4, the distance between the light shielding layer 225 and the substrate 221 sandwiching the gate electrode 223 and the gate insulating film 222 is d.
In the present invention, the light shielding layer 225 and the semiconductor substrate 22 are formed by thinning the gate electrode 223 of the VCCD section.
The distance d between 1 and 1 is set to 600 nm or less.

With this structure, the light-shielding layer-substrate distance satisfies the formula (1) everywhere the active region is present. Therefore, the effect of blocking the leaking light works sufficiently, and it becomes possible to reduce the smear level to −80 dB or less.

Here, since the distance d between the light shielding layer and the substrate in the VCCD section satisfies the mathematical expression (1), it is not necessary to provide an inactive region as in the conventional image pickup element, and the aperture ratio of the PD is correspondingly increased. It is possible to raise.

Further, even if misalignment occurs at the time of patterning the light-shielding layer and the edge of the light-shielding layer 235 shifts to the VCCD side as shown in FIG. As long as 1) is satisfied, the smear characteristic does not deteriorate. Therefore, it is possible to widen the margin for misalignment.

As described above, the design margin can be widened by eliminating the inactive region on the PD which satisfies the formula (1) required for the conventional image sensor and widening the margin for misalignment. Becomes

Further, in such a structure, Al
Even if misalignment occurs during the patterning of the light shielding layer 225, the thin film of the gate electrode 223 reduces the PD portion and the VCC.
Since the step difference with the D section is suppressed to be small, before and after the boundary area extending from the PD section to the VCCD section,
Since the light-shielding layer 225 can be formed to have a uniform thickness, it is possible to prevent the light-shielding layer 225 from being disconnected, and improvement of smear resistance can be expected. This makes it possible to prevent a decrease in yield due to deterioration of smear characteristics due to step breakage of the light shielding layer 225, which has been a problem in the past. As described above, the use of the present invention improves the smear resistance and
By increasing the design margin, it is possible to increase the density of the image sensor by miniaturizing the pixel cells. Further, the present invention is not limited to the above-described embodiments, and various modifications can be carried out without departing from the scope of the invention.

[0048]

According to the present invention, the following operational effects can be expected.

(1) The n-type impurity diffusion layer of the photoelectric conversion storage portion and the transfer electrode of the vertical CCD portion are formed to overlap each other. As a result, the photoelectric conversion storage unit and the vertical transfer CCD
Can be formed in a self-aligned process, and the aperture ratio of the photoelectric conversion storage part can be increased even when miniaturization is advanced. Therefore, even if the element area becomes smaller due to miniaturization, the area of the photoelectric conversion storage section can be made larger, so that a solid-state imaging device having high sensitivity can be realized.

(2) The gate electrode is thinned, and the distance d between the light shielding layer and the semiconductor substrate sandwiching the gate electrode is 600 nm.
Below. As a result, the light-shielding layer-substrate distance satisfies Expression (1) everywhere the active region is present, and the smear level can be set to −80 dB or less.

Therefore, it is not necessary to provide an inactive region unlike the conventional image pickup device, and the aperture ratio of the PD can be increased accordingly. Furthermore, it is possible to widen the margin for misalignment.

Since the light shielding layer can be formed with a uniform thickness by thinning the gate electrode, it is possible to prevent the breakage of the light shielding layer as in the conventional case and improve the smear resistance. Can be expected. Therefore, by improving the smear resistance and expanding the design margin, it is possible to increase the density of the image sensor by miniaturizing the pixel cells.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a pixel portion of a solid-state imaging device according to a first embodiment of the present invention.

2 is an example of a process flow for making the device of FIG.

FIG. 3 is another example of a process flow for making the device of FIG.

FIG. 4 is yet another example of a process flow for making the device of FIG.

FIG. 5 is a schematic cross-sectional view of a pixel portion of a solid-state imaging device according to a second embodiment of the present invention.

FIG. 6 is a schematic sectional view of a pixel portion of a solid-state imaging device according to a third embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing an example of a pixel portion of a conventional solid-state imaging device in which a photoelectric conversion storage portion and a vertical transfer CCD are formed by separate lithography steps.

FIG. 8 is a diagram illustrating the reason why the photoelectric conversion storage unit and the vertical transfer CCD are formed in different lithography steps in the manufacture of the conventional solid-state imaging device.

FIG. 9 is a plan view of a pixel cell portion of a solid-state imaging device according to Example 4 of the present invention.

10 is a sectional view of a pixel cell portion of the solid-state imaging device of FIG.

FIG. 11 is a diagram for explaining an influence when the size of the light shielding layer in FIG. 9 varies.

FIG. 12 is a diagram showing a relationship between a film thickness d between a light shielding layer and a substrate and smear.

FIG. 13 is a cross-sectional view showing an example of a pixel cell portion of a conventional solid-state image sensor.

[Explanation of symbols]

101 ... Transfer electrodes of vertical transfer CCD, 102 ... P-type impurity diffusion layer of photoelectric conversion storage unit, 103 ... N-type impurity diffusion layer (impurity diffusion layer) of photoelectric conversion storage unit, 104 ... N-type impurity diffusion of vertical transfer CCD Layers, 105 ... P-well, 106 ... N-type substrate, 107 ... Gate insulating film, 108 ... Oxide film, 109 ... SiN film, 110, 111 ... Resist, 112 ... Second layer resist, 221 ... Semiconductor substrate, 222 ... Gate insulating film, 223 ... Gate electrode (vertical transfer electrode), 224 ... Interlayer insulating film, 225 ... Light-shielding layer.

Claims (2)

[Claims] 1. A plurality of photoelectric conversion storage units arranged two-dimensionally on a semiconductor substrate, wherein an impurity diffusion layer forming a signal charge storage diode for storing signal charges generated by incident light is provided. A photoelectric conversion storage unit having the same, a plurality of vertical transfer CCDs having transfer electrodes for reading and transmitting the charges stored in the impurity diffusion layer of the photoelectric conversion storage unit, and a horizontal transfer for receiving signals from the vertical transfer CCDs in the horizontal direction. A solid-state image pickup device comprising a transfer CCD, wherein the impurity diffusion layer and a transfer electrode adjacent to the impurity diffusion layer overlap each other. 2. A photodiode formed on the surface of a semiconductor substrate for converting incident light into an electric signal to accumulate charges, and a photodiode formed on the semiconductor substrate via a gate insulating film. A vertical transfer electrode forming a charge-coupled device for taking out the electric charge stored in the device to the outside of the device, an interlayer insulating film formed so as to cover the entire device including the photodiode and the vertical transfer electrode, and the interlayer insulating film. In the solid-state imaging device, which is provided on the film so as to cover the vertical transfer electrodes and includes a light shielding layer for preventing light from entering the vertical transfer electrodes, the interlayer insulating film and the vertical transfer electrodes And a distance d between the light shielding layer and the semiconductor substrate with the gate insulating film sandwiched therebetween: d ≦ 600 nm (1)