JP3012100B2 - Method for manufacturing solid-state imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for manufacturing a solid-state imaging equipment.

[0002]

2. Description of the Related Art In recent years, a solid-state imaging device and a method of manufacturing the same have been used for a small video camera for business use, a high-resolution video movie for business use, and a high-definition still camera.

Hereinafter, an example of a conventional solid-state imaging device and a method of manufacturing the same will be described.

In a conventional solid-state imaging device, all parts are initially formed using inorganic substances such as aluminum wiring and a silicon oxide film formed on a silicon substrate. Accordingly, an organic material is directly formed on the upper part of the solid-state imaging device to achieve colorization of the solid-state imaging device and increase sensitivity by using an on-chip microlens.

[0005]

However, in the above-mentioned conventional structure, an organic color filter which is discolored by ultraviolet rays or the like, or a white filter or cracks caused by ultraviolet rays, is formed on a highly reliable solid-state image sensor made of an inorganic substance. The microlens composed of the resulting organic matter is directly formed. For this reason, there is a problem that a solid-state imaging device that forms an organic material and achieves higher performance has a shorter product life than a product life of a solid-state imaging device that does not use an organic material alone.

An object of this invention to reduce the deterioration of optical characteristics due to influence of ultraviolet rays, is to provide a method for manufacturing a solid-state imaging equipment that can reduce the extension of the reliability and product life.

[0007]

A solid-state imaging device according to the present invention.
Is to form a glass flat film on a solid-state imaging device.
Process and a convex semi-elliptical organic micro
A lens forming step and a convex semi-elliptical organic micro lens
Pseudo-sine wave by applying organic microlens material
Of forming an organic microlens and a pseudo sine waveform
Etching rate of organic microlens and glass flat film
Pseudo-sinusoidal organic microlens under conditions of equality
Pseudo dry sine
Forming a corrugated glass microlens
It is characterized by that.

[0008]

SUMMARY OF According to the manufacturing method of the solid-state imaging equipment of the present invention,
By configuring the microlens formed directly on the solid-state imaging device with an inorganic material, it is possible to reduce the deterioration of the optical characteristics due to the influence of ultraviolet rays and the like, thereby improving the reliability of the solid-state imaging device and the product life. Can be extended.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 shows a solid-state imaging device according to an embodiment of the present invention.
FIG. 2 is a process cross-sectional view illustrating a method for manufacturing an image device, and FIG.
Sectional view of a solid-state imaging device manufactured by the manufacturing method shown in
It is. FIGS. 5, 7, and 8 show the present invention.
Steps showing a method of manufacturing a solid-state imaging device as a basis of an embodiment
FIGS. 1, 3 and 4 are sectional views, respectively.
7. Solid-state imaging device manufactured by the manufacturing method shown in FIG.
FIG.

First, the manufacturing which is the basis of the embodiment of the present invention
The solid-state imaging device of FIG. 1 manufactured by the method will be described.
I do. In Figure 1, 1 is a solid-state imaging device, 2 is concave photodiodes, 3 SiO ₂ [glass] transparent planarization film, 4 is a semi-elliptical SiO ₂ micro lenses.

[0011] The solid-state imaging device, the concave photodiode gelled high visible light transmittance, which is formed of a glass material SiO ₂ transparent planarization film 3 on top of 2 in the solid-state imaging device 1 is provided, further SiO ₂ transparent planarization A semi-elliptical SiO 2 is formed on the upper portion of the film 3 by using a gel glass material having a high visible light transmittance.
_Two micro lenses 4 are provided. For this reason, the visible light incident on the semi-elliptical SiO ₂ microlens 4 is condensed on the concave photodiode 2 to enhance the sensitivity of the solid-state imaging device, improve the reliability by all-inorganization, and extend the product life. be able to.

Next, FIG. 2 shows an embodiment of the present invention.
The solid-state imaging device will be described. In FIG. 2, reference numeral 5 denotes a sinusoidal waveform SiO ₂ microlens, and the other components are the same as those in FIG.

In the example of FIG . 1, visible light incident on the flat inter-lens area of the semi-elliptical SiO ₂ microlens 4 is Si
Since the light is perpendicularly incident on the O ₂ transparent flat film 3, it is not focused on the concave photodiode 2. Therefore, in this embodiment, by replacing the sine wave SiO ₂ microlens 5 showing the semi-elliptical SiO ₂ microlenses 4 of FIG. 1 in FIG. 2, the visible light incident perpendicularly to the SiO ₂ transparent planarization film 3 And the amount of visible light that can be collected on the concave photodiode 2 is increased.
This makes it possible to further increase the sensitivity of the solid-state imaging device.

Next, the example of FIG. 3 will be described. 3, 6 is a SiO ₂ transparent flat film, 7 is a magenta pigment dispersion film, 8 is a yellow pigment dispersion film, 9 is a green pigment dispersion film, 10 is a cyan pigment dispersion film, and the others are the same as FIG. .

In FIG . 1 and FIG. 2 , the SiO ₂ transparent flat film 3 is colorless and transparent and transmits all visible light, so that it cannot cope with the colorization of the solid-state imaging device. Therefore, in this example , as shown in FIG. 3, a magenta pigment dispersion film in which an inorganic pigment is pulverized into fine particles having a diameter of 50 nm or less which does not cause reduction in visible light transmittance and uniformly dispersed in a gel glass material. 7, a yellow pigment dispersion film 8, a green pigment dispersion film 9 and a cyan pigment dispersion film 10 are arranged on the SiO ₂ transparent flat film 3, respectively.
An inorganic color filter block is provided by blocking so as to obtain a desired color. And covering these inorganic color filter blocks with SiO ₂ transparent planarization film 6, a semi-elliptical SiO ₂ on top of the SiO ₂ transparent flat film 6
A micro lens 4 is provided.

According to this embodiment, it is possible to improve the reliability and extend the product life of the solid-state imaging device by increasing the sensitivity and all-inorganic, and to obtain a highly reliable solid-state imaging device which is less affected by fading due to ultraviolet rays. The device can be colored.

Next, the example of FIG. 4 will be described. 4, the same reference numerals as those in FIG. 3 denote the same parts.

In the example of FIG . 3, an inorganic color filter block of a total of four colors of a magenta pigment dispersion film 7, a yellow pigment dispersion film 8, a green pigment dispersion film 9 and a cyan pigment dispersion film 10 is formed on the SiO ₂ transparent flat film 3. They were provided on the same plane.
However, because a mineral pigment dispersion film without color mixture be laminated,
In this example , as shown in FIG.
By laminating a cyan pigment dispersion film 10 on top of this, the same color as that of the green pigment dispersion film 9 in FIG. 3 can be synthesized, and the number of pigments required for colorization is reduced from four to three.
The number of types can be reduced, and the manufacturing process can be shortened.

In the examples of FIGS. 3 and 4, instead of the semi-elliptical SiO ₂ microlens 4, a sinusoidal SiO ₂ microlens 5 in the embodiment of FIG. 2 may be provided. Further, an organic dye having high light resistance may be used in place of the inorganic pigment.

Next, the manufacturing which forms the basis of the embodiment of the present invention will be described.
The method will be described with reference to FIG. In FIG. 5, 3
a is a gel glass film, 11 is a thermoplastic organic flat film, 12
Is a SiO ₂ transparent flat film, 13 is a photosensitive organic microlens material, and 14 is a convex semi-elliptical organic microlens.

In FIG. 5A, a sol glass liquid (tetraethoxysilane = TEOS) is spin-coated on the upper surface of the concave photodiode 2 in the solid-state imaging device 1, and
5 μm thick gel-like glass film 3a heated at 50 ° C. for 5 minutes
To form After spin-coating a thermoplastic synthetic resin on the upper surface of the gel glass film 3a, it is heated and softened at 130 ° C. for 5 minutes to form a thermoplastic organic flat film 11.

In FIG. 5B, CF ₄ : O ₂ = 1: 4 at a vacuum of 0.05 Torr at which the etching rates of the thermoplastic organic flat film 11 and the gel glass film 3a become equal.
The thermoplastic organic flat film 11 and the gel glass film 3a are continuously dry-etched at a gas flow ratio of.

In FIG. 5 (c), the gel-like glass film 3a is over-etched until the thermoplastic organic flat film 11 completely disappears to form the SiO ₂ transparent flat film 3.

In FIG. 5D, the sol glass liquid is spin-coated on the upper surface of the SiO ₂ transparent flat film 3 and then heated at 150 ° C.
And heated for 5 minutes to form a SiO ₂ transparent flat film 1 to 3 μm thick
Form 2 A photosensitive organic microlens material 13 is spin-coated on the upper surface of the SiO ₂ transparent flat film 12 and then selectively exposed.

In FIG. 5E, the photosensitive organic microlens material 13 is developed.

In FIG. 5F, the photosensitive organic microlens material 13 is heated and deformed at 150 ° C. for 2 minutes to form a convex semi-elliptical organic microlens 14.

[0027] In FIG. 5 (g), the convex semi-elliptical organic microlens 14 and convex under conditions etching rate of the SiO ₂ transparent planarization film 12 is equal semi-elliptical organic microlens 14 and the SiO ₂ transparent flat film 12 is continuously dry-etched.

[0028] Figure 5 in (h), the convex semi-elliptical SiO overetching the SiO ₂ transparent flat film 12 until the convex semi-elliptical organic microlens 14 has completely disappeared
_Two micro lenses 4 are formed.

As described above, according to this example , the semi-elliptical S
A solid-state imaging device capable of condensing the visible light incident on the iO ₂ microlens 4 on the concave photodiode 2 to improve the sensitivity of the solid-state imaging device, improve reliability by all-inorganization, and extend the product life. Can be realized.

Next, the solid-state imaging device according to the embodiment of the present invention will be described.
The manufacturing method will be described with reference to FIG. In FIG. 6, reference numeral 15 denotes a sine waveform organic micro lens (pseudo sine waveform organic micro lens). The sine waveform Si
O ₂ microlens 5 is a pseudo-sinusoidal waveform condensing glass microlenses, SiO ₂ transparent planarization film 12 is glass flat
It is a membrane.

In FIG. 6A, the steps of forming the convex semi-elliptical organic microlenses 14 on the SiO ₂ transparent flat film 12 are the same as those in FIGS. 5A to 5F.

In FIG. 6B, an organic microlens material whose viscosity is reduced to 10 to 20 cp is spin-coated on the upper surface of the convex semi-elliptical organic microlens 14 to form a continuous sinusoidal organic microlens 15. I do.

[0033] In FIG. 6 (c), under conditions in which the etching rate of the sinusoidal organic microlens 15 and the SiO ₂ transparent planarization film 12 are equal, continuous dry etching a sine waveform organic microlens 15 and the SiO ₂ transparent planarization film 12 Thus, a sinusoidal waveform SiO ₂ microlens 5 is formed.

As described above, according to this embodiment, a sinusoidal SiO ₂ microlens 5 is formed instead of the semi-elliptical SiO ₂ microlens 4 in FIG.
The amount of visible light that can be focused on the concave photodiode 2 is increased by reducing the amount of visible light that is perpendicularly incident on the SiO ₂ transparent flat film 3, and a solid-state imaging device with higher sensitivity can be realized.

Next, the example of FIG. 7 will be described. In FIG. 7, reference numeral 16 denotes a resist pattern formed of a photosensitive resist.

In FIG. 7A, the step of forming the SiO ₂ transparent flat film 3 is the same as in FIGS. 5A to 5C. A magenta pigment dispersing material, which is obtained by pulverizing the magenta inorganic pigment into fine particles having a diameter of not more than 50 nm not to reduce the transmittance of visible light and uniformly dispersing the same in a sol-like glass liquid, is spin-coated on the SiO ₂ transparent flat film 3. C. for 5 minutes to form a magenta pigment dispersion film 7a having a thickness of 0.5 to 2 .mu.m. A photosensitive resist is spin-coated on the magenta pigment dispersion film 7a, and is selectively exposed and developed to form a desired resist pattern 16.

In FIG. 7B, the resist pattern 1
6 is used as a mask to dry-etch the magenta pigment dispersed film 7a to form a desired block-shaped magenta pigment dispersed film 7.

In FIG. 7C, FIG. 7A and FIG.
A yellow pigment dispersion film 8, a green pigment dispersion film 9, and a cyan pigment dispersion film 10 having desired block shapes are formed in the same manner as described above.

In FIG. 7D, the SiO ₂ transparent flat film 3 is covered with SiO 2 so as to cover the pigment dispersion film of four colors.
_{2 The} transparent flat film 6 is formed in the same manner as the SiO ₂ transparent flat film 3.

In FIG. 7 (e), FIGS. 5 (d) to 5 (h)
A convex semi-elliptical SiO ₂ microlens 4 is formed on the SiO ₂ transparent flat film 6 in the same manner as described above.

According to this example, it is possible to improve the reliability and extend the product life of the solid-state imaging device by increasing the sensitivity and all-inorganic, and to achieve the coloration with less influence of fading by ultraviolet rays. , A solid-state imaging device with high performance can be realized.

Next, the example of FIG. 8 will be described.

In FIG. 8A, FIG. 7A to FIG.
A magenta pigment dispersion film 7 and a yellow pigment dispersion film 8 are formed on the SiO ₂ transparent flat film 3 in the same manner as described above. A cyan pigment dispersion film 10 is formed on the yellow pigment dispersion film 8 by spin coating. A photosensitive resist is spin-coated on the cyan pigment dispersion film 10 and then selectively exposed and developed to form a resist pattern.
To form a down 1 7.

In FIG. 8B, the resist pattern 1
7 is used as a mask to dry-etch the cyan pigment dispersed film 10 to form a yellow pigment dispersed film 8 and a cyan pigment dispersed film 10.
To form a two-stage green composite color filter.

In FIG. 8C, a SiO ₂ transparent flat film 6 is formed so as to cover the pigment dispersion film in the same manner as in FIG. 7D.

In FIG. 8D, a semi-elliptical microlens 4 is formed on the SiO ₂ transparent flat film 6 in the same manner as in FIG. 7E.

[0047] According to this embodiment, as compared with FIG. 7, by laminating a cyan pigment dispersion film 10 on the yellow pigment dispersion film 8, the same as the green pigment dispersion film 9 in FIG. 7 (see FIG. 7) Colors can be synthesized, the number of kinds of pigments required for colorization can be reduced from four to three, and the manufacturing process can be shortened.

In the examples shown in FIGS. 7 and 8 , a sinusoidal SiO ₂ microlens 5 is formed instead of the semielliptical SiO ₂ microlens 4 as in the embodiment of FIG. The amount of visible light that can be condensed into the light is increased, and a solid-state imaging device with higher sensitivity can be realized.

In each of the examples including the above embodiment, tetraethoxysilane (TEO) was used as the inorganic transparent glass material.
Although S) was used, the inorganic transparent glass material is not limited to tetraethoxysilane, but may be any glass material capable of forming a low-temperature glass film by a sol-gel method.

Further, inorganic color filter materials in which fine particles are dispersed in tetraethoxysilane are magenta, yellow,
The color is not limited to four colors of green and cyan, and may be any color. For example, there are red, blue, and black. Note that an organic dye having high light resistance may be used instead of the inorganic pigment.

[0051]

According to the present invention as described above, according to the present invention, by constructing the microlens directly formed on the solid-state imaging device of an inorganic material, it is possible to reduce deterioration of optical characteristics due to influence of ultraviolet rays, It is possible to improve the reliability of the solid-state imaging device and extend the product life.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a solid-state imaging device on which an embodiment of the present invention is based.

2 is a sectional view of a solid-state imaging device of the actual施例of the present invention.

FIG. 3 is a cross-sectional view of a solid-state imaging device that is a basis of an embodiment of the present invention.

FIG. 4 is a sectional view of a solid-state imaging device which is a basis of the embodiment of the present invention.

FIG. 5 is a process sectional view illustrating a method for manufacturing a solid-state imaging device which is a basis of the embodiment of the present invention.

6 is a process cross-sectional views showing a manufacturing method of a solid-state imaging device of the actual施例of the present invention.

FIG. 7 is a process sectional view illustrating the method of manufacturing the solid-state imaging device which is the basis of the embodiment of the present invention.

FIG. 8 is a process sectional view illustrating the method of manufacturing the solid-state imaging device which is the basis of the embodiment of the present invention.

[Explanation of symbols]

1 solid-state imaging element 2 concave photodiode 3a gel glass film 3 SiO ₂ transparent planarization film 4 semi-elliptical SiO ₂ microlens 5 sinusoidal SiO ₂ microlenses 6 SiO ₂ transparent planarization film 7a magenta pigment dispersion film 7 Magenta pigment dispersion film Reference Signs List 8 yellow pigment dispersion film 9 green pigment dispersion film 10 cyan pigment dispersion film 11 thermoplastic organic flat film 12 SiO ₂ transparent flat film 14 convex semi-elliptical organic microlens 15 sinusoidal organic microlens 16 resist pattern 17 resist pattern

Continuation of front page (56) References JP-A-4-73968 (JP, A) JP-A-4-1602 (JP, A) JP-A-58-224310 (JP, A) JP-A-2-151804 (JP) , A) JP-A-61-102602 (JP, A) JP-A-56-13479 (JP, A) Japanese Translation of PCT International Publication No. 3-500834 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB (Name) G02B 5/20 101

Claims (1)

(57) [Claims] A glass flat film is formed on a solid-state imaging device.
And forming a convex semi-elliptical organic electrode on the glass flat film.
Forming a chlorolens, and the convex semi-elliptical organic polymer.
Apply organic microlens material on the
Forming a similar sinusoidal organic microlens;
Pseudo sinusoidal organic microlens and glass flat film
The pseudo sine wave under the condition that the etching rate of
Continuous organic microlens and the glass flat film
Etching and pseudo-sinusoidal condensing glass microlens
Solid-state imaging comprising:
Device manufacturing method.