JP2002246576A - Image sensor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that an edge vicinity of a passivation film formed above a photodiode region is not flat, so a vertical component of light hitting the part is refracted and a light to the photodiode region attenuates. SOLUTION: An image sensor comprises a photodiode region where an incident light is photoelectric-converted on the surface of a semiconductor substrate into a signal charge and then accumulated, a gate which comprises an opening pattern to form the photodiode region and transfers the signal charge outward, a lower layer wiring formed on the gate using a wiring pattern matching the opening pattern through an insulating film a top wiring which is formed over it based on a light shielding pattern that matches the opening pattern of the gate through an interlayer insulating film while an opening region is enlarged by a prescribed shift width, and a passivation film so formed as to cover it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image sensor and a method of manufacturing the same, and more particularly to an improvement in the light condensing property of a photodiode region.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a schematic cross-sectional view showing a conventional typical image sensor disclosed in Japanese Patent Application Laid-Open Publication No. HEI 10-125, in which 11 is a P-type semiconductor substrate, 12 is an N-type active region, forming a photodiode region, Is a gate made of polysilicon or a silicide of a high melting point metal, 21 and 22 are lower wirings made of aluminum or other alloy, respectively, a first wiring and a second wiring arranged above the first wiring, and 23 is a wiring made of aluminum or other metal. It is a top wiring made of an alloy and works as a light shielding film. Reference numeral 14 denotes an insulating film formed by depositing BPSG, DPSG, or the like by a normal low-pressure CVD method,
Reference numerals 15 and 16 denote interlayer insulating films, each of which is a plasma CV.
First and second insulating films 17 formed by laminating planarizing films such as D method, SOG, and TEOS in a predetermined order, and 17 is a passivation film made of a nitride film or an oxide film. In the figure,
A section between XX ′ indicates a light receiving portion of the photodiode region 12 and usually forms a rectangular pattern, photoelectrically converts incident light to accumulate signal charges, and a circle A indicates an overhang of the passivation film 17. Is shown.

Next, a method of manufacturing a conventional image sensor will be briefly described. Photodiode region 1 in FIG.
The second light receiving portion is formed by ion-implanting N-type impurities such as boron and arsenic between adjacent gates 13 and performing heat treatment. Then, through a metallization, a lithography technology, and a planarization process using an SOG film,
The patterns are aligned and laminated so that at least the gate 13 and the side surface of the top wiring 23 on the photodiode region 12 side are vertically aligned. And the top wiring 2
A passivation film 17 is formed on the third and second insulating films by deposition using a plasma CVD method. Note that the passivation film 17 is overhanged at the shoulder of the top wiring 23 (circle A in the figure).

Next, the operation will be described. The incident light narrowed by the top wiring 23 as a light shielding film via the passivation film 17 is transmitted to the second insulating film 16 and the first insulating film 1.
5. After passing through the insulating film 14, the light reaches the photodiode region 12, which is a light receiving portion. After the light reaches the photodiode region 12, the light is photoelectrically converted and accumulated as signal charges. Through the gate 13, the signal is output to an external device as a video signal via an output unit.

[0005]

Since the conventional image sensor and its manufacturing method are configured as described above, the vicinity of the edge of the passivation film 17 formed above the photodiode region 12 is not flat. Due to the overhang (circle A), the vertical component of the light hitting that portion is refracted, and therefore, there is a problem that the light reaching the photodiode region 12 is attenuated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and eliminates an overhang portion of a passivation film on a photodiode region.
It is an object of the present invention to obtain an image sensor with improved sensitivity by eliminating a light attenuation region and a method for manufacturing the same.

[0007]

According to the present invention, there is provided an image sensor formed on a surface of a semiconductor substrate and photoelectrically converting incident light to accumulate as signal charges, and an opening pattern defining the photodiode region. A gate for transferring signal charges to the outside, a lower wiring formed on the gate with a wiring pattern matching the opening pattern via an insulating film, and a gate opening pattern on the gate via an interlayer insulating film And a top wiring formed on the basis of a light-shielding pattern in which an opening area is enlarged by a predetermined shift width and a passivation film formed so as to cover the top wiring.

In the image sensor according to the present invention, the light-shielding pattern of the top wiring has a shift width larger than that of the opening pattern by at least the thickness of the passivation film.

In the image sensor according to the present invention, the lower wiring has a multilayer wiring structure.

In the image sensor according to the present invention, the passivation film is formed by a multilayer film including a planarization film.

In the image sensor according to the present invention, the flattening film is composed of an SOG film and a TEOS film.

In the image sensor according to the present invention, an insulating sidewall is formed on a side surface of the top wiring.

In the image sensor according to the present invention, the top wiring has a predetermined taper angle with respect to a vertical direction and forms a forward taper.

According to a method of manufacturing an image sensor according to the present invention, a semiconductor substrate has a photodiode region for performing photoelectric conversion, and an opening pattern defining the region, and transmits a signal charge generated in the photodiode region to the outside. A second step of forming an insulating film on the entire surface, forming a lower layer wiring with a wiring pattern matching the opening pattern, and forming an interlayer insulating layer thereon. After the film is formed on the entire surface, a third step of aligning the top wiring with the opening pattern of the gate and forming the top wiring based on the light-shielding pattern in which the opening area is enlarged by a predetermined shift width, and covering the third step. And a fourth step of forming a passivation film as described above.

In the method of manufacturing an image sensor according to the present invention, the pattern of the top wiring is formed so as to have a shift width larger than the opening pattern by at least the thickness of the passivation film.

In the method of manufacturing an image sensor according to the present invention, in the second step, the interlayer insulating film includes the first and second insulating films, and the lower wiring is formed on the first insulating film. The method includes a step of forming one wiring and a second wiring formed on the second insulating film.

In the method of manufacturing an image sensor according to the present invention, in the fourth step, the passivation film is formed by a multilayer film including a flattening film.

In the method of manufacturing an image sensor according to the present invention, the flattening film is composed of an SOG film and a TEOS film.

The method of manufacturing an image sensor according to the present invention further comprises, in the fourth step, after forming an insulating sidewall film, etching the entire surface to form a sidewall on the side surface of the top wiring. Things.

The method of manufacturing an image sensor according to the present invention further comprises, in the third step, a step of forming a side surface of the top wiring with a predetermined forward taper angle.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a schematic cross-sectional structure diagram showing an image sensor according to Embodiment 1 of the present invention, and FIG. 2 is a process cross-sectional view of this image sensor, showing a device having a three-layer structure as an example. In the figure, reference numeral 11 denotes a P-type semiconductor substrate, and reference numeral 12 denotes an N-well active region obtained by ion-implanting N-type impurities such as boron and arsenic, which constitutes a photodiode region. Reference numeral 13 denotes a gate formed of polysilicon or a refractory metal silicide, for example, when viewed from the top, in a rectangular opening pattern to define the photodiode region 12, and 21 and 22 denote lower wirings made of aluminum or another alloy. A first wiring and a second wiring formed above the first wiring by a wiring pattern.
Wiring.

Reference numeral 23 designates a top wiring similarly formed of aluminum or another alloy, and formed by a light-shielding pattern having an opening area enlarged by a predetermined width in order to restrict the incident light reaching the photodiode area 12. Function as a light-shielding film. In the drawing, the wiring patterns of the lower layer wirings, that is, the wiring patterns of the first and second wirings 21 and 22 are drawn so as to be aligned with the opening pattern of the gate 13 in the vertical direction. May also expand outwardly.

Reference numeral 14 denotes B by a normal low pressure CVD method.
An insulating film formed by depositing PSG, DPSG, etc., 15,
Reference numeral 16 denotes an interlayer insulating film, a first and a second insulating film formed by laminating planarizing films such as a plasma CVD method, SOG, and TEOS in a predetermined order, a passivation film 17 including a nitride film or an oxide film, 51 is a register mask, X
And X ′ line are vertical lead lines along the side surface of the gate 13 defining the photodiode region 12, T1 is the thickness of the passivation film 17, and T2 is the top wiring 23.
Is the pattern shift width from the X and X 'lines outward. The first to third wirings may be made of aluminum alone or a mixture of aluminum and copper, titanium or the like.

Next, a method of manufacturing the image sensor according to the first embodiment will be described with reference to the process sectional views of FIGS. First, a gate 13 having a predetermined opening pattern is formed on a P-type semiconductor substrate 11 through lithography (ST1).
An active region is created between the adjacent gates 13 by implanting boron and arsenic ions through 1 to form a photodiode 12 (ST2). On top of this, the normal decompression CV
After the insulating film 14 is deposited or formed by the method D, a first wiring 21 having a predetermined wiring pattern matched with the opening pattern is formed through metallization and lithography.
Deploy.

Further, TEOS by plasma CVD is used.
A first insulating film 15 is formed by using a flattening film such as SOG and SOG, and a second wiring 22 having a predetermined other wiring pattern is similarly disposed thereon through metallization and lithography, as described above. A second insulating film 16 including a flattening film is formed using a plasma CVD method (ST3).

On top of this, the top wiring 23 is aligned with the opening pattern of the gate separating the photodiode region and the edges of the first and second wirings 21 and 22 of the lower wiring, and is shifted from the opening pattern by a predetermined shift width. A top wiring having a light shielding pattern is formed in the spreading direction. This shift width is possible under various conditions according to the device design, but is formed by a pattern shifted outward by at least the thickness (T1) of the passivation film 17 to be coated thereon. Note that FIG. 2D shows a line shifted from the vertical X and X 'lines by T2 (> T1).

Finally, an image sensor is completed by forming a passivation film 17 covering the entire surface with the above-mentioned thickness (T1) (ST4).

Next, the operation will be described. The incident light narrowed by the top wiring 23 as a light shielding film via the passivation film 17 is transmitted to the second insulating film 16 and the first insulating film 1.
5. After passing through the insulating film 14, the light reaches the photodiode region 12, which is a light receiving portion. After the light reaches the photodiode region 12, the light is photoelectrically converted and accumulated as signal charges. Through the gate 13,
Through the output unit, the video signal is extracted to an external element, for example, as a video signal.

At this time, the overhang portion generated near the edge of the top wiring 23 of the passivation film 17 over the photodiode region 12 is such that the light-shielding pattern of the top wiring 23 extends outward by T2 from the X and X 'lines. Therefore, only a flat portion can be formed above the photodiode region 12, and the light collecting property can be improved. As a result, such a problem that the incident light is attenuated due to refraction of the vertical component of light as in the related art is solved.

As described above, according to the first embodiment, since the overhang portion of the passivation film 17 can be excluded from the photodiode region 12, the effect of light scattering at that portion can be eliminated. ,
Passivation film 17 on photodiode region 12
Has an effect of enlarging the flat region and improving the sensitivity.

Embodiment 2 FIG. 3A is a schematic sectional structural view showing an image sensor according to a second embodiment of the present invention, and FIG. 3B is a process sectional view of the image sensor. In FIG. Is SOG
The film, 33 is a plasma TEOS film, and 34 is a passivation film, and the other configuration is the same as that of the first embodiment, and the description is omitted. In the figure, the second insulating film 1
The portion below 6 is omitted.

The feature of FIG. 3A is that the passivation film 17 according to the first embodiment is multi-layered. That is, after forming the top wiring 23 based on a light-shielding pattern in which the opening area of the top wiring 23 is enlarged by a predetermined shift width, for example, a pattern in which the opening pattern is enlarged by the thickness (T1) of the passivation film, Δ-TEOS
After a film 31, an SOG film 32, and a plasma TEOS film 33 are formed in this order and the uppermost layer is made flat, a passivation film 34 is formed. The passivation film 34 is formed thinner than the passivation film 17 described above.
A multilayer film is set to have this thickness. Note that the shift width corresponding to the above T1 can be set smaller by improving the flatness.

This advantage is achieved by using a multilayer film to reduce the step between the top wiring 23 and the interlayer film, and to reduce the overhang near the edge of the top wiring 23 when the passivation film 34 is formed. As a result, the passivation film 34 on the photodiode region 12 becomes flat, scattering of incident light is reduced, and the sensitivity is improved. The shift width can be set to be smaller than T2 due to the improvement of the flatness.

Next, a method of manufacturing the image sensor according to the second embodiment will be described with reference to a process sectional view of FIG. Until the top wiring is formed (ST2-1),
In the same manner as described in the first embodiment, the Δ-TEOS film 31 is formed by depositing the Δ-TEOS film 31 by the plasma CVD method on the top wiring 23 formed by a desired light-shielding pattern and the second insulating film serving as an interlayer insulating film. (ST2-2).
Then, the SOG film 32 as a planarizing film is spin-coated,
It is formed through a heat treatment (ST2-3). Further, Δ−T
A plasma TEOS film 33 is formed in the same manner as the EOS film 31 (ST2-4), and a passivation film 34 is formed thereon to complete (ST2-5).

The Δ-TEOS film 31 and the TEOS film 3
The difference of 3 is that the former improves the step coverage by selectively using two types of RF frequencies and depositing them.
Although there are some differences in physical properties in terms of refractive index, there is no significant difference in insulation, moisture resistance, and other film properties.

As described above, according to the second embodiment, as described in the first embodiment, the single-layer passivation film 17 is constituted by the Δ-TEOS film 31, the SOG film 32, and the TEOS film 33. By using a multilayer film to be formed, the flatness can be improved, whereby the effect of reducing the scattering of incident light and improving the sensitivity can be obtained.

Embodiment 3 FIG. 4A is a schematic sectional structural view showing an image sensor according to Embodiment 3 of the present invention, and FIG. 4B is a process sectional view of this image sensor. In FIG. Since the other structure is the same as that of the first embodiment, the description is omitted. In the figure,
The portion below the second insulating film 16 is omitted.

The feature of FIG. 4A is that the side wall 35 is formed on the side surface of the top wiring 23 in a state where the opening area of the light-shielding pattern of the top wiring 23 is enlarged as in the first embodiment. Overhang due to the passivation film 17 near the edge of the top wiring 23 can be reduced, and attenuation of incident light due to overhang can be reduced as in the first embodiment.
In addition, since the passivation film 17 can be formed conformally, that is, with good consistency, the thickness can be reduced to the extent that the function as a protective film is not impaired. By reducing the thickness of the passivation film, light attenuation can be further suppressed, which leads to an improvement in the sensitivity of the photodiode. Note that the thinning of the passivation film 17 also leads to a reduction in manufacturing cost.

Next, a method of manufacturing the image sensor according to the third embodiment will be described with reference to a process sectional view of FIG. Until the top wiring is formed (ST3-1),
The same as described in the first embodiment,
A TEOS film 35 is formed on the top wiring 23 formed by a desired light-shielding pattern and the second insulating film serving as an interlayer insulating film by deposition by a plasma CVD method (ST3-2).
The thickness of the TEOS film 35 is based on the thickness of the top wiring 23 and may be slightly larger. And this TEO
Etchback is performed on the S film 35 under the conditions of anisotropic etching of the entire surface of the insulating film (ST3-3). A passivation film 17 is formed thereon to complete the process (ST3-4).

The insulating film used for the side wall 35 is made of various plasma-based oxide films, nitride films, and SO.
A G film can also be used.

As described above, according to the third embodiment, the plasma TEOS film 3
Since the side wall of the insulating film made of 5 or the like is formed on the side surface of the top wiring 23, the thickness of the passivation film 17 can be made thinner than usual, and the overhang appearing near the edge of the top wiring 23 is reduced. Therefore, as in the first embodiment,
The attenuation of the incident light due to the overhang can be reduced, and the effect of reducing the manufacturing cost can be obtained. Furthermore, since the passivation film 17 can be formed with good consistency by forming the sidewalls, the passivation film 17 can be made thinner so as not to impair the function as a protective film, for example, moisture resistance, and the effect of suppressing light attenuation can be obtained.

Embodiment 4 5 is a schematic sectional view showing an image sensor according to Embodiment 4 of the present invention. In the figure, reference numeral 23 denotes a top wiring having a taper angle θ of 45 to 60 degrees with respect to a vertical direction and a side surface having a forward tapered shape. The other configuration is the same as that of the first embodiment, and the description is omitted. In the figure, the second insulating film 16
The lower part is omitted.

The feature of FIG. 5 is that, similarly to the above, the overhang of the passivation film 17 near the edge of the top wiring 23 is eliminated, and the thickness of the passivation film 17 itself functions as a protective film, for example, while maintaining moisture resistance. The point is that the attenuation of the incident light can be suppressed.
Further, since the top wiring 23 is formed with a predetermined taper angle, the oblique component light is not blocked from the top wiring 23 having a vertical side surface as shown in FIG. The light collecting property is improved.

The method of manufacturing the image sensor according to the fourth embodiment is the same as that of the first embodiment except that the method of forming the top wiring 23 is different. I do.

Although there is a method of performing this by an etching method, here, it is considered that a resist pattern serving as an etching mask is tapered. That is, regarding the formation of the resist pattern before etching for forming the light-shielding pattern of the top wiring 23, the resist pattern is tapered by shifting the focus from the optimum condition in the processing conditions of the exposure apparatus during the photolithography process. Then, if normal etching is performed based on the completed resist pattern, the top wiring 23 having the above taper angle can be obtained.

As described above, according to the fourth embodiment, since the top wiring 23 is formed so as to have a predetermined taper angle and to have a forward taper, the top wiring 23 has an oblique component as compared with the case where the side surface is vertical. The effect that the blocking of the incident light is suppressed and the light collecting property is improved is obtained.

It should be noted that the first to fourth embodiments are used.
In the above, the multilayer wiring including the first wiring and the second wiring has been described as the lower wiring, but the invention is not limited to this, and the lower wiring may be a single layer.

[0048]

As described above, according to the present invention, the top wiring is formed based on the light-shielding pattern matching the opening pattern of the gate defining the photodiode region, and the passivation film is formed so as to cover it. And
Since the light-shielding pattern of the top wiring is matched with the opening pattern of the gate and is formed based on the light-shielding pattern in which the opening area is enlarged by a predetermined shift width,
An overhang portion of the passivation film generated near the edge of the top wiring can be excluded from above the photodiode region, and the influence of light scattering at the overhang portion can be eliminated. As a result, the flat area of the passivation film on the photodiode is widened, so that the light collecting property is improved, and the sensitivity of the photodiode and thus the image sensor is improved.

According to the present invention, the light-shielding pattern of the top wiring is configured to have a shift width that is at least as large as the thickness of the passivation film than the opening pattern. It can be excluded from the upper part of the photodiode area to eliminate the influence of light scattering at the overhang part,
As a result, the flat region of the passivation film on the photodiode is expanded, so that there is an effect that the light collecting property is improved and the sensitivity is improved.

According to the present invention, since the lower wiring has a multilayer wiring structure, there is an effect of providing an image sensor having a three-layer structure of metal wiring.

According to the present invention, since the passivation film is formed of a multilayer film including a flattening film, the overhang at the edge of the top wiring is reduced by improving the flatness, and the manufacturing process is stabilized. ,
This has the effect of providing a highly sensitive image sensor with improved light collection. In addition, there is an effect that the shift width can be reduced.

According to the present invention, since the flattening film is composed of the SOG film and the TEOS film, if these are combined and laminated, there is an effect that the passivation film with improved flatness as described above can be realized.

According to the present invention, since the insulating side wall is formed on the side surface of the top wiring, the amount of overhang appearing near the edge of the top wiring is reduced, so that the overhang portion of the passivation film is reduced. It can be easily removed from the upper part of the photodiode region to eliminate the influence of light scattering at the overhang portion, and thereby the flat region of the passivation film on the photodiode is expanded, so that the light collecting property is improved and the There is an effect that sensitivity is improved.

According to the present invention, since the top wiring has a predetermined taper angle with respect to the vertical direction and is formed so as to form a forward taper, the amount of overhang is reduced, and the Since the flat region of the passivation film on the diode is widened, there is an effect that the light collecting property is improved and the sensitivity is improved.

According to the present invention, the first step is to form a gate having an opening pattern for defining a photodiode region and transmitting a signal charge to the outside, and the second step is to form an insulating film over the entire surface. The lower wiring is formed by a wiring pattern enlarged to be larger than the opening pattern, and the third step forms the interlayer insulating film on the entire surface, and then the top wiring is aligned with the opening pattern of the gate, and the opening area is enlarged by a predetermined shift width. Since the method for manufacturing the image sensor is formed based on the light-shielding pattern thus formed, and the fourth step forms the passivation film thereon, the overhang portion of the passivation film generated near the edge of the top wiring is formed above the photodiode region. And the effect of light scattering at the overhang portion can be eliminated. As a result, the flat area of the passivation film on the photodiode is widened, so that the light collecting property is improved, and the sensitivity of the photodiode and thus the image sensor is improved.

According to this invention, the pattern of the top wiring is formed so as to have a shift width that is at least as large as the opening pattern by the thickness of the passivation film. By eliminating the overhang portion from the upper portion of the photodiode region, the effect of light scattering at the overhang portion can be eliminated. There is an effect that sensitivity is improved.

According to the present invention, in the second step,
A step of forming a first wiring formed on the first insulating film and a second wiring formed on the second insulating film as a lower wiring, wherein the first and second insulating films are included in the interlayer insulating film; , The effect of realizing a multilayer wiring structure is obtained.

According to the present invention, in the fourth step,
Since the passivation film is formed of a multilayer film including a flattening film, the overhang at the edge of the top wiring is reduced due to the improvement in flatness, the manufacturing process is stabilized, and the light collecting property is improved and the sensitivity is high. There is an effect of providing an image sensor. In addition, there is an effect that the shift width can be reduced.

According to the present invention, since the flattening film is composed of the SOG film and the TEOS film, if these are combined and stacked, there is an effect that the passivation film with improved flatness as described above can be realized.

According to the present invention, in the fourth step,
After the insulating sidewall film is formed, the entire surface is etched to form a sidewall on the side surface of the top wiring. This further reduces the amount of overhang that appears near the edge of the passivation film. The overhang portion of the photodiode can be easily removed from the upper portion of the photodiode region to eliminate the influence of light scattering at the overhang portion, thereby expanding the flat region of the passivation film on the photodiode, and condensing light. And the sensitivity is improved.

According to the present invention, in the third step,
Since the top wiring is formed so as to have a predetermined forward taper angle on the side surface, the amount of overhang is reduced, and as described above, the flat region of the passivation film on the photodiode is expanded. And the sensitivity is improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional structural view showing an image sensor according to Embodiment 1 of the present invention.

FIG. 2 is a process sectional view illustrating the method for manufacturing the image sensor according to Embodiment 1 of the present invention.

FIGS. 3A and 3B are a schematic cross-sectional structure diagram showing an image sensor according to a second embodiment of the present invention, and a process cross-sectional diagram showing a manufacturing method thereof, respectively; FIGS.

FIG. 4A is a schematic cross-sectional structure diagram showing an image sensor according to Embodiment 3 of the present invention, and FIG. 4B is a process cross-sectional diagram showing a manufacturing method thereof.

FIG. 5 is a schematic sectional view showing an image sensor according to a fourth embodiment of the present invention.

FIG. 6 is a schematic sectional structural view showing a conventional image sensor.

[Explanation of symbols]

11 semiconductor substrate, 12 photodiode region, 13
Gate, 14 insulating film, 15 first insulating film (interlayer insulating film), 16 second insulating film (interlayer insulating film), 17, 34
Passivation film, 21 first wiring (lower wiring), 2
2 Second wiring (lower wiring), 23 Top wiring, 31
Δ-TEOS film (multilayer film, flattening film), 32 SOG film (multilayer film, flattening film), 33 plasma TEOS film (multilayer film, flattening film), 51 resist mask.

Continued on the front page (72) Inventor Masatoshi Kimura 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 4M118 AA01 CA03 5F033 MM19 QQ08 QQ09 QQ16 QQ31 QQ34 RR04 RR06 RR09 RR14 RR15 SS04 SS13 SS15 TT02 TT08 UU04 XX01 5F049 MA02 MB03 MB12 NA01 NB03 PA10 QA15 RA04 RA08 SS02 SZ12

Claims (14)

[Claims] 1. A photodiode region formed on a surface of a semiconductor substrate for photoelectrically converting incident light to accumulate as signal charges, and an opening pattern defining the photodiode region, and transferring the signal charges to the outside. A gate, a lower wiring formed on the gate with a wiring pattern matched with the opening pattern via an insulating film, and a predetermined shift from the lower wiring matched with the opening pattern of the gate via an interlayer insulating film. An image sensor comprising a top wiring formed based on a light-shielding pattern whose opening area is enlarged by a width, and a passivation film formed so as to cover the top wiring. 2. The image sensor according to claim 1, wherein the light-shielding pattern of the top wiring has a shift width larger than that of the opening pattern by at least the thickness of the passivation film. 3. The image sensor according to claim 1, wherein the lower wiring has a multilayer wiring structure. 4. The image sensor according to claim 1, wherein the passivation film is formed of a multilayer film including a flattening film. 5. The image sensor according to claim 4, wherein the flattening film comprises an SOG film and a TEOS film. 6. The image sensor according to claim 1, wherein an insulating sidewall is formed on a side surface of the top wiring. 7. The image sensor according to claim 1, wherein the top wiring has a predetermined taper angle with respect to a vertical direction and forms a forward taper. 8. A photodiode region for performing photoelectric conversion on a semiconductor substrate, and a gate having an opening pattern defining the region and for transmitting signal charges generated in the photodiode region to the outside. A first step, an insulating film is formed on the entire surface, a second step of forming a lower wiring with a wiring pattern matching the opening pattern, and an interlayer insulating film is formed on the entire surface. A third step of aligning the top wiring with the opening pattern of the gate and forming the top wiring based on a light-shielding pattern in which the opening area is enlarged by a predetermined shift width, and forming a passivation film so as to cover the upper part. A method of manufacturing an image sensor, comprising: 9. The method for manufacturing an image sensor according to claim 8, wherein the pattern of the top wiring is formed with a shift width larger than the opening pattern by at least the thickness of the passivation film. 10. In a second step, an interlayer insulating film includes first and second insulating films, and a lower layer wiring includes a first wiring formed on the first insulating film and a second insulating film. 9. The method according to claim 8, further comprising the step of forming a second wiring formed thereon. 11. The method according to claim 8, wherein in the fourth step, the passivation film is formed by a multilayer film including a planarization film. 12. The method according to claim 11, wherein the flattening film comprises an SOG film and a TEOS film. 13. The method according to claim 8, further comprising, after forming an insulating sidewall film, performing a whole surface etching to form a sidewall on a side surface of the top wiring. Method for manufacturing an image sensor. 14. The method according to claim 8, further comprising the step of forming the side surface of the top wiring with a predetermined forward taper angle in the third step.