JPH05226624A - Solid-state image pick-up device and its manufacture - Google Patents

Abstract

PURPOSE:To provide a stable solid image pick-up device and its manufacturing method which do not induce deterioration of characteristics even if the cell size of a picture element is miniaturized. CONSTITUTION:The surface of a passivation film 31 in the title device is flattened. Then, a light-absorbing film 32 is formed on a light-screening film 3 which is formed on the surface of a transfer part 5 so that light for exposure which is used for exposure process used when forming a film of a color filter 4 does not induce unneeded reflection, thus improving the edge cutting property of colored regions 41-43 of the film, eliminating horizontal streaks and color mixing.

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 structure suitable for miniaturization and a manufacturing method thereof.

[0002]

2. Description of the Related Art A solid-state image pickup device is an LSI that fulfills three functions of photoelectric conversion, storage, and scanning. For scanning, an electronic beam in an image pickup tube is not used, and pulses are sent in a circuit to form a mosaic pattern. Signals are taken out sequentially from independent pixels. This device is promising as a camera for various monitoring televisions and high-definition televisions. This is because it cannot be obtained with the image pickup tube, there is no image distortion, low voltage, low power consumption, small size and light weight, little afterimage, no burning due to direct sunlight, and strong against shock, etc. Development is progressing toward high image quality, high sensitivity, and low cost. The photoelectric conversion and scanning can basically be mentioned as the functions required for the image pickup device which becomes the pixel of the image pickup device. In a solid-state imaging device, these functions can be created on one chip, and therefore, devices having various characteristics are being developed by combining various photoelectric conversion methods and scanning methods. In particular, a color filter for colorization is formed on the photoelectric conversion unit, which is a light receiving unit, and a microlens or the like is attached on each light receiving unit to increase the amount of light received. is the current situation.

In particular, for example, CCD (Charge Coupled
A solid-state imaging device using a charge-coupled device such as a device) in a transfer unit is roughly divided into a frame transfer system and an interline transfer system. In the inter-line transfer method, as shown in FIG. 13, the light receiving portions 2 including the light receiving elements 21 are separated from each other, and a block of the signal charges for each of the light receiving portions is the transfer portion 5 through the transfer gate. Once transferred to the vertical CCD. Then, a group of signal charges of each line is sequentially sent out from the vertical CCD to the horizontal CCD on the output side and read out as a time series signal. The above-described color filter formed on the photoelectric conversion portion is known as a single-plate color solid-state imaging device.

FIG. 14 shows an example of a conventional single-plate color solid-state image pickup device, and partially shows a sectional view of a light receiving portion and a transfer portion formed on a semiconductor substrate. Light receiving portions and transfer portions are formed alternately on the semiconductor substrate 1. One solid-state image sensor includes the light receiving section and the transfer section to form a pixel. These solid-state imaging devices are shown in FIG.
As shown in FIG. 3, it is formed in the surface region of the semiconductor substrate 1 aligned vertically and horizontally. First, an impurity diffusion layer having a high impurity concentration is formed at predetermined intervals, and these are used as a photo diode 2 serving as a light receiving portion. As shown in the figure, a transfer unit 5 is provided between the photodiodes 2, converts the received light into electric charges, and outputs the generated electric charges through the transfer unit. The transfer unit 5 has, for example, a CCD structure. Since the generation and recombination of charges due to the surface states at the oxide film-silicon interface of the transfer portion causes noise, a buried channel CCD (BCCD: Buried channel) is generated.
CCD) is often used. In this type, a thin opposite conductivity type layer is formed on a semiconductor substrate, and majority carriers separated by a depletion layer are transferred in this layer, which enables high speed operation. By using this BCCD, noise of this kind is reduced and at the same time transfer efficiency is improved.

Above the transfer unit 5, mainly around the light receiving unit,
The light shielding film 3 is formed to prevent light from leaking from the outside. As the light shielding film 3, an Al film made of Al or its alloy is usually used. Other than the Al film, Cr, W or the like is used. A passivation film 31 is provided so as to cover the light receiving portion 2, the transfer portion 5, the light shielding film 3, and the like. As the material of the passivation film, a material transparent to the received light such as an acrylic film is usually used. The color filter 4 is formed on the passivation film 31. Color filter 4
Is composed of a colored film such as gelatin or casein,
Each region 41, 42, 43 of this colored film is dyed with a predetermined color. For example, the colored film 41 is red and the colored film 42 is
Is dyed in green, and the colored film 43 is dyed in blue.

An example of the conventional method of manufacturing the solid-state image pickup device will be described with reference to FIGS. 14 and 15. For example,
A p-type well region (not shown) is formed on the n-type silicon semiconductor substrate 1, and a plurality of n ⁺ diffusion layers are formed in a predetermined region on the surface thereof by an ion implantation method or the like to form a photo diode. 21 to constitute the light receiving section 2.
A transfer unit 5 is formed between the light receiving elements 21, and has a CCD structure (vertical CCD), for example. The light shielding film 3 made of an Al film is formed on the surface of the transfer portion (FIG. 15A). Next, the semiconductor substrate 1
A passivation film 31 is formed on the surface of the. As the material, an acrylic film or the like which is transparent to the received light is used. A film to be dyed 40 made of a filter material such as casein or gelatin is applied on the passivation film 31, and the film to be dyed 40 is first exposed through a photomask 6 by using a normal lithography technique (see FIG. 15
(B)). Next, this is developed and dyed to form a colored film 41 on the passivation film 31 (FIG. 15).
(C)). Further, second and third colored films 42 and 43 are deposited on the exposed portion of the passivation film 31,
A color filter 4 including these colored films 41 to 43 is formed (FIG. 14).

[0007]

As described above, in the conventional solid-state image pickup device, the colored film 41 of the color filter is used.
Etc. are patterned by a lithographic technique. But,
As shown in FIG. 14, the side surface of the edge of each colored film is not formed vertically, but has a shape with a long skirt and sunk under another colored film. This is due to the underlying layer on which the color filter is mounted. That is, the light receiving unit 2
Since the transfer portion 5 has a step, and the passivation film 31 thereabove also has a step, the alignment accuracy between the semiconductor substrate 1 and the photomask 6 apparently deteriorates. ), The irradiation light at the time of exposure is reflected by the Al-based film used for the light shielding film 3 and the wiring (not shown), so that the predetermined position of the film to be dyed 40 is patterned. Becomes difficult. As described above, when the colored films are formed so as to overlap with each other, flicker, horizontal stripes, color mixing, and the like occur, and the characteristics of the imaging device are deteriorated. Therefore, it is difficult to miniaturize the solid-state imaging device. The above is the problem regarding the color filter, but the same problem occurs in the case of the microlens. In order to form one lens, the film of the lens material is processed using the photolithography technique, and if there is reflected light from the underlayer of this film in the exposure process, it is affected by this and the accurate lens The shape of will not be obtained. The present invention has been made under such circumstances, and an object of the present invention is to provide a stable solid-state imaging device that does not deteriorate in characteristics even if the cell size of a pixel is miniaturized, and a manufacturing method thereof.

[0008]

The present invention provides a passivation film having a planarized surface of a solid-state image pickup device having a plurality of pixel regions having a light receiving portion and a transfer portion, and
It is characterized in that the light absorption layer is formed at least on the light shielding film formed on the transfer portion. That is, the solid-state imaging device of the present invention includes a semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, A passivation film which covers the pixel region and the light shielding film and has a flattened surface, and a color filter or a microlens formed on the flattened passivation film are formed on the surface. The first feature is that the color filter is provided. Further, a semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, the pixel region and the light shielding film. The second feature is that it has a passivation film that covers the surface and has a flattened surface, and a microlens formed on the flattened passivation film. A light absorption film may be formed on the light shielding film, and the passivation film absorbs the exposure light used in the exposure process for forming the color filter or the microlens. Can be provided with sex. Further, a semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, the pixel region and the light shielding film. A passivation film, a light absorbing film formed on the light shielding film, and a color filter formed on the passivation film or a color filter formed on the surface of a microlens. The third feature is the provision. A semiconductor substrate; a plurality of pixel regions formed on the semiconductor substrate, each having a light receiving part made of a photodiode and a transfer part made of a charge-coupled device; a light shielding film formed on the transfer part of the pixel region; A passivation film that covers the pixel region and the light shielding film and has a flattened surface, a light absorption film formed on the light shielding film, and a passivation film that has the flattened surface. The fourth feature is that the color filter is provided on the film.

The solid-state imaging device manufacturing method of the present invention comprises the steps of forming a plurality of pixel regions having a light receiving portion and a transfer portion on a semiconductor substrate, and forming a light shielding film on the transfer portion of the pixel region. , Passivate the pixel region and the light shielding film.
A passivation film, a step of flattening the surface of the passivation film by heating and softening the passivation film, and a color filter or a microlens on the flattened surface of the passivation film. The first feature is that it includes a step of forming a color filter having a microlens formed on the surface. Also,
Forming a plurality of pixel regions having a light receiving portion and a transfer portion on a semiconductor substrate; forming a light shielding film on at least the transfer portion of the pixel region; and passivating the pixel region and the light shielding film. Of the passivation film, irradiating the region on the light receiving portion of the passivation film with light to make the region transparent, and heating the passivation film to flatten its surface. And a region of the passivation film on the light receiving portion is formed into a light absorbing film having a spectrum that absorbs exposure to light when forming a color filter or a microlens, and the passivation film. Forming a color filter or a microlens or a color filter having a microlens formed on the surface thereof on the flattened surface of the application film. The is a second feature. A photosensitizer may be added to the passivation film in advance.

[0010]

[Function] The passivation film is flattened and the light absorption layer is formed, so that the colored films overlap with each other due to a step or light reflection, and the pattern size variation due to misalignment of the photomask becomes large. There is no adverse effect.

[0011]

Embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of the solid-state imaging device, and FIGS. 2 to 4 are cross-sectional views of the manufacturing process thereof. The one shown in this figure is a single-plate color solid-state image pickup device having a color filter attached, and has, for example, an interline transfer system structure as shown in FIG. The light receiving section 2 including the light receiving element 21 is separated from each other, and a block of signal charges is transferred once to each light receiving section through the transfer gate to the shielded vertical CCD which is the transfer section 5. Then, a group of signal charges of each line is sequentially sent out from the vertical CCD to the horizontal CCD and read out as a time series signal. The light receiving portions 2 and the transfer portions 5 are alternately formed on the semiconductor substrate 1. One solid-state image pickup device is provided with one light receiving unit and one transfer unit to form a pixel. As shown in FIG. 13, these solid-state imaging devices are formed in a surface region of the semiconductor substrate 1 aligned vertically and horizontally. First, an impurity diffusion layer having a high impurity concentration is formed at predetermined intervals, and these are used as a photo diode 21 which becomes the light receiving portion 2. As shown in the figure, a transfer unit 5 is provided between the photodiodes 21, converts the received light into electric charges, and outputs the generated electric charges through the transfer unit. This transfer unit 5 is, for example, CC
It has a D structure. Since the generation and recombination of charges due to the surface states at the oxide film-silicon interface of the transfer part causes noise generation, the BCCD may be used.
This use reduces noise and at the same time improves transfer efficiency.

A light shielding film 3 is formed around the light receiving portion 2 and mainly on the transfer portion 5 to prevent light from leaking from the outside. As the light shielding film 3, an Al film made of Al or its alloy is usually used. Other than the Al film, Cr or W can be used. A passivation film 31 is provided so as to cover the light receiving portion 2 and the transfer portion 5. Then, another passivation film 32 is formed on the main part of the light shielding film 3. The passivation film 32 has a function of absorbing light used in an exposure process when forming a color filter by a lithographic technique, and thus can be used as the light absorbing film 32. For the passivation film, a material transparent to the received light, such as a positive photoresist, is usually used. A color is formed on the passivation films 31 and 32.
The filter 4 is formed. The color filter 4 is, for example,
It is composed of a film to be dyed such as gelatin or casein, and this film to be dyed is divided into predetermined regions, and each region is dyed with a predetermined color to form colored films 41 to 43. For example, the colored film 41 corresponds to red, the colored film 42 corresponds to green, and the colored film 43 corresponds to blue. The passivation film 32 is the colored film 4.
It is formed under the boundary of each region of 1 to 43. Since light absorption at this portion is sufficiently performed during exposure, reflection of the light shielding film 3 is prevented, and pattern edge deformation of the colored film is eliminated. Both the passivation films 31 and 32 are
Since the common flat surface is formed, the photomask and the semiconductor substrate 1 are accurately aligned with the colored films 41 to 43 formed thereon. As a result, the colored films 41 to 43 serving as the color filter 4 are formed by a predetermined pattern, and flicker, color mixing, horizontal stripes, etc. are significantly reduced. The passivation film 31 is generally used as a solid-state image pickup device 400.
It is transparent to visible light with a wavelength of up to 700 nm, while the passivation film 32 on the light shielding film 3 is colored.
It is a spectrum that absorbs the irradiation light in the exposure process of lithography at the time of making the filter. For example, when the i-line is used, for example, a positive photoresist having absorption at a wavelength of 365 nm is used as the material of the passivation film 32. Thus, the present invention can be easily implemented by appropriately selecting the material of the passivation film according to the wavelength of light used in the exposure step.

Next, a manufacturing method of the first embodiment will be described with reference to sectional views of manufacturing steps of the solid-state image pickup device shown in FIGS. A p-type well region (not shown) is formed in an n-type silicon semiconductor substrate 1 used as a semiconductor substrate, and a plurality of n ⁺ diffusion layers are formed in a predetermined region on the surface thereof by an ion implantation method or the like to obtain a photo diode, These are the light receiving elements 21
To form the light receiving unit 2. The surface on which the light receiving element is formed is covered with a silicon oxide film (SiO ₂ ), and a p-type high impurity concentration region is provided between the silicon oxide film and the n ⁺ diffusion layer so as to separate the two. Can be formed and the photodiode can be embedded to reduce noise generation. A transfer unit 5 is formed between the light receiving elements 21, which has, for example, a CCD structure (vertical CC).
D). An Al film 3 serving as a light-shielding film is formed on the surface of this transfer portion by a vapor deposition method or the like (FIG. 2). Next, the passivation film 32 is formed on the surface of the semiconductor substrate 1. As the material, a film such as a positive photoresist such as polystyrene or polymethylmethacrylate that is transparent to received light is used. The passivation film 32 is deposited to cover the light receiving portion 2, the transfer portion 5, and the light shielding film 3 on the transfer portion. Next, the passivation film 3
2 is exposed to light and the exposed part is made transparent (FIG. 2). As shown in the figure, a photomask 6 is interposed when light is applied to prevent the light from hitting the portion above the light shielding film 3. The passivation film 32 in the portion of the light shielding film 3 does not become transparent because it is not exposed to light and becomes a light absorption film 32 having a spectrum that absorbs i-line (wavelength 365 nm). The portion exposed to light, that is, the portion of the passivation film on the light receiving portion 2 becomes transparent and becomes the passivation film 31 (FIG. 3). Next, heat treatment of the passivation films 31 and 32 is performed. The passivation film (light-absorbing film) 32 is fixed by this heat step and is not changed by the subsequent light. At the same time, the heat treatment softens and fluidizes the passivation film to flatten its surface (FIG. 3).

By this heat step, it is possible to add a curing agent so that the curing proceeds, and immobilize it so as not to react in the subsequent steps. Further, here, although it is immobilized by heat, it may be immobilized by a chemical reaction. Although the passivation film serving as the light absorption film 32 is formed integrally with the passivation film 31, another material can be formed as the passivation film 31 after the light absorption film 32 is formed. .. Conversely, it is also possible to form the passivation film 31 and then form the light absorption film 32. Next, this passivation film 31, 3
2 is coated with a dyed film 40 made of a filter material such as casein or gelatin, and the dyed film 40 is first exposed through the photomask 6 using a normal lithographic technique, and then developed and dyed. Then, the colored film 41 is formed (FIG. 4). Continuing, passivation film 3
The second and third colored films 42 and 43 are deposited on the exposed portion of No. 1 to form the color filter 4 made of these colored films (FIG. 1). Flat passivation films 31, 32
Since the light absorption film 32 is formed on the above, the light shielding film 3 does not reflect the light and each colored film 4 is formed.
The edges 1 to 43 are formed almost vertically.

Next, a second embodiment will be described with reference to FIG. FIG. 5 is a partial cross-sectional view of the solid-state imaging device. The difference of this embodiment from the above-mentioned embodiments is that the passivation film is entirely composed of the light absorption film 32 shown in FIG. This passivation film 3
As the film 2, a film such as a positive photoresist fixed by the above-mentioned heat is used. If this is used, in the step of forming the passivation film, the step of making transparent is not necessary, and only the heat step is necessary. According to the characteristic diagram (FIG. 12) showing the relationship between the light transmittance T of this material and the wavelength, it is transparent in the visible region having a wavelength of about 400 to 700 nm, and the lithography forming the color filter 4 is performed. It is a spectrum that absorbs a wavelength of 365 nm of i-line, which is a typical example of light used for exposure of the technology. Moreover, the passivation film 32 covering the light receiving portion 2 and the transfer portion 5
However, since it has a flattened surface like the solid-state imaging device of the above-mentioned embodiment, it is possible to provide a good color filter pattern shape without degrading the characteristics of the color filter. it can.

Next, a third embodiment will be described with reference to FIG. The figure is a partial cross-sectional view of the solid-state imaging device. In this example, the passivation film is not provided with the light absorption film 32, only the passivation film 31 transparent to visible light is formed, and the surface thereof is flattened. This is the same as the first embodiment in which light is used for transparency and heat is used for flattening. However, since a mask is not used for the transparentization process, the light absorption film is not formed and only the transparent passivation film 31 is formed. On the flat passivation film 31, colored films 41, 42 and 43 which form the color filter 4 are formed. Since the light absorbing film is not formed, the light of the exposure process at the time of forming the colored film is reflected by the light shielding film 3 and affects the edge formation of the colored film, but the passivation film 31 is flattened. Therefore, the deformation of the pattern edges of these colored films is improved. Moreover, since a mask is not required in the transparentization process, the manufacturing process is simplified.

Next, a fourth embodiment will be described with reference to FIGS. 7 is a partial cross-sectional view of the solid-state imaging device, and FIG. 8 is a cross-sectional view of the manufacturing process thereof. In this example,
The color filter 4 composed of the colored films 41, 42 and 43 is formed on the flattened passivation films 31 and 32, and each of the light receiving portion 2 and the transfer portion 5 is formed thereon. The microlens 7 made of a convex lens is formed so as to be arranged above the pixel. Since the amount of light is increased by the action of this convex lens, the sensitivity of the solid-state imaging device is improved. Further, the passivation film 31 may be interposed between the microlens 7 and the color filter 4. In forming a lens by etching, which will be described later, a lens material may be used for the passivation film.

There are three possible methods for forming the microlens 7, as shown in FIGS. 8 and 9. First, the first is a lens forming method by etching. As shown in FIG. 8, a lens material film (lens film) 70 is colored.
It is deposited on the filter 4. As the material, an acrylic or polystyrene film is usually used. Then, a novolac-based positive photoresist or the like is used, and an appropriate etching process is performed to form a surface region having a plurality of convex portions. The surface is heat-treated to form the convex portion into a convex lens shape. Then, the entire surface is subjected to etching treatment such as oxygen plasma etching to reduce the thickness of this film while maintaining the state where the convex portion is present, and finally a microlens having the convex portion as a lens is formed. With this method, it is possible to select a lens material that is not easily affected by heat (FIG. 9).
(A)). The second is a method using a lithographic technique. After depositing the lens film 70 on the color filter 4, a plurality of convex portions are formed, and then heat treatment is performed to form the surface into a convex lens shape (FIG. 8). Although this method limits the lens material, it is suitable for miniaturization of semiconductor devices. A third method is to form a plurality of convex portions 71 made of a negative photoresist and deposit the lens film 70 on the convex portions 71. Since a convex lens-shaped convex portion is formed on the convex portion, this is referred to as a microlens 7 (FIG. 9B). In this method, microlenses are easily formed, but the degree of freedom of light converging property is
It is inferior to the lens shape obtained by the first and second methods.

Next, a fifth embodiment will be described with reference to FIG. The figure is a partial cross-sectional view of the solid-state imaging device. No color filter is formed in this image pickup device,
The microlens 7 is directly formed on the passivation film 31. The lens is formed by using one of the methods shown in the previous embodiment, for example, the third method.

Next, a sixth embodiment will be described with reference to FIG. The figure is a partial cross-sectional view of the solid-state imaging device. In this solid-state imaging device, the surface of the passivation film 31 is not flattened. However, since the light absorption film 32 that absorbs the exposure light in the exposure process in forming the color filter 4 made of, for example, a positive photoresist such as acrylic resin is provided on the light shielding film 3, The influence of reflected light from the light shielding film 3 is eliminated, and patterns such as color filters are formed with high accuracy. In order to form the light absorption film 32, in the exposure step of making the passivation film 31 transparent, only this portion is masked so that light is not applied to prevent the passivation film 31 from becoming transparent. That is, a part of the passivation film 31 is used as a light absorbing film.

As described above, in the above-described embodiments, the passivation film and the microlenses are made of a positive photoresist such as acrylic or polystyrene. This is used because it is a spectrum that easily becomes transparent in the visible light region by exposure and absorbs the i-line (wavelength 365 nm) used in the exposure process in the current semiconductor device manufacturing process. The invention is
The material is not limited to this material, and any material having such characteristics can be used.
The present invention can also be applied to the case where excimer laser light or X-rays is used as the light used in this exposure step. That is, any material that absorbs these lights and is transparent in the visible light region can be applied.

FIG. 12 is a characteristic diagram for explaining the wavelength λ dependence of the light transmittance T of this positive photoresist. When exposed to positive photoresist, this material yields nearly 100
The light transmittance of% is shown. However, heat treatment without exposure,
When fixed, the wavelength λ becomes 36 as shown by the curve A in the figure.
It absorbs i-rays of 5 nm and absorbs visible light (400-70
Since it exhibits about 50% absorption at 400 nm at the edge of (0 nm), it does not become transparent. Therefore, in the present invention, in order to utilize the positive photoresist, for example, naphthoxydiazide, which is a diazo-based photosensitizer, is mixed in the photoresist, and the photoresist is exposed to light such as represented by a curve B in the figure. A material having transmittance-wavelength characteristics is obtained. By blending this photosensitizer at an appropriate ratio, a material having a desired light transmittance-wavelength characteristic can be obtained. This material is almost transparent in the visible light region and has a spectrum that absorbs i-rays. In the present invention, a material having such characteristics is used for the passivation film and the microlens.

In the above embodiment, the photodiode is used as the light receiving portion and the CCD is used as the transfer portion. However, the present invention is not limited to these elements. The solid-state image sensor basically has photoelectric conversion and scanning functions. Since these functions have many photoelectric conversion methods and scanning methods, these can be combined in various ways in the present invention. It is possible. In the photoelectric conversion method, there are a MOS capacitor type, a photoconductive film laminated type, etc. in addition to the photodiode type. The scanning system includes a system using a CCD, a system using a blocking diode, a MOS switch, a MOS switch-CCD, a CID (Charge Injection Device) and the like, and these can be appropriately combined. Furthermore, although the n-type silicon semiconductor substrate is used in these examples, the conductivity type of the semiconductor substrate is arbitrary in the present invention. For example, a p-type silicon semiconductor substrate can be used, but in that case, it is not necessary to form the p-type well region.

[0024]

As described above, according to the present invention,
The pattern shape of the color filter used in the solid-state imaging device may be greatly varied or the mask may be misaligned due to the step difference of the passivation film formed thereunder or the reflection of the light shielding film. As a result, it is possible to increase the degree of integration without causing characteristic deterioration such as flicker, horizontal stripes, and color mixing.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a manufacturing process of the solid-state imaging device of FIG.

3A and 3B are cross-sectional views of manufacturing steps of the solid-state imaging device of FIG.

4A to 4C are cross-sectional views of manufacturing steps of the solid-state imaging device in FIG.

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

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

FIG. 7 is a sectional view of a solid-state imaging device according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view of a manufacturing process of the solid-state imaging device of FIG.

FIG. 9 is a cross-sectional view illustrating the method of manufacturing the solid-state imaging device of the present invention.

FIG. 10 is a sectional view of a solid-state imaging device according to a fifth embodiment of the present invention.

FIG. 11 is a sectional view of a solid-state imaging device according to a sixth embodiment of the present invention.

FIG. 12 is a characteristic diagram showing wavelength dependency of light transmittance of a passivation film.

FIG. 13 is a plan view showing a main part of the solid-state imaging device.

FIG. 14 is a sectional view of a conventional solid-state imaging device.

FIG. 15 is a sectional view of a manufacturing process of a conventional solid-state imaging device.

[Explanation of symbols]

 1 semiconductor substrate 2 light receiving part 21 light receiving element 3 light shielding film 31 passivation film 32 light absorbing film 4 color filter 40 film to be dyed 41 colored film 42 colored film 43 colored film 5 transfer part 51 vertical CCD 52 horizontal CCD 6 photomask 7 Microlens 70 Lens film 71 Convex portion in lens film

Claims (9)

[Claims] 1. A semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, the pixel region and the light. A passivation film that covers the shielding film and has a flattened surface; and a color filter formed on the flattened passivation film or a color filter formed on the surface of the microlens. A solid-state image pickup device comprising. 2. A semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, the pixel region and the light. A solid-state imaging device comprising: a passivation film that covers a shielding film and has a flattened surface; and a microlens formed on the flattened passivation film. 3. The solid-state imaging device according to claim 1, wherein a light absorption film is formed on the light shielding film. 4. The passivation film is the color film.
The solid-state imaging device according to claim 1 or 2, wherein the solid-state imaging device has a light absorbing property with respect to exposure light used in an exposure process for forming a filter or a microlens. 5. A semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate and having a light receiving portion and a transfer portion, a light shielding film formed on the transfer portion of the pixel region, the pixel region and the light. A passivation film covering the shielding film; a light absorbing film formed on the light shielding film; a color filter formed on the passivation film or formed on the passivation film. And a color filter having a microlens formed on the surface thereof. 6. A semiconductor substrate, a plurality of pixel regions formed on the semiconductor substrate, each pixel region having a light receiving part made of a photodiode and a transfer part made of a charge-coupled device, and a light formed on the transfer part of the pixel region. A light-shielding film, a passivation film covering the pixel region and the light-shielding film and having a flattened surface, a light-absorbing film formed on the light-shielding film, and the surface being flattened. And a color filter formed on the passivation film. 7. A step of forming a plurality of pixel regions having a light receiving part and a transfer part on a semiconductor substrate, a step of forming a light shielding film on the transfer part of the pixel region, the pixel region and the light shielding film. With a passivation film, a step of flattening the surface by heating and softening the passivation film, and a color filter on the flattened surface of the passivation film. Or a step of forming a microlens or a color filter having a microlens formed on the surface thereof. 8. A step of forming a plurality of pixel regions having a light receiving portion and a transfer portion on a semiconductor substrate, a step of forming a light shielding film on at least the transfer portion of the pixel region, the pixel region and the light shielding A step of covering the film with a passivation film, a step of applying light to an area on the light receiving portion of the passivation film to make the area transparent, and heating the passivation film. A step of flattening the surface of the passivation film and forming a region on the light receiving portion of the passivation film into a light absorption film having a spectrum that absorbs exposure to light when forming a color filter or a microlens. And a step of forming the color filter or the microlens on the flattened surface of the passivation film or the color filter having the microlens formed on the surface. Method for manufacturing a solid-state imaging device characterized in that it comprises a. 9. The method for manufacturing a solid-state imaging device according to claim 7, wherein a photosensitizer is added to the passivation film in advance.