JPH09162377A - Solid state image pickup element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a good solid state image pickup element by avoiding formation of an uneven layer with transparent resin charged in pixel recesses, this omitting the coating step of a flat layer. SOLUTION: A photoelectric signal interconnection layer 4 is formed on the surface layer part of a solid state image pickup element substrate 1, pixel recesses 2 are formed into this layer like a regular matrix, light receiving parts 3 are formed at the bottoms of the recesses 2. and light-transmissive layer 5 is formed by charging transparent resin in the recesses 2 and composed of first and second light-transmissive layers 6 and 7. A color filter layer 8 composed of a red, green and blue color layers R, G, B are formed on the layer 5.

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 such as CCD for picking up a monochromatic image or a color image,
In particular, the present invention relates to a solid-state image sensor including a light-transmissive layer obtained by filling a transparent resin in a pixel recess formed in a wiring layer formed on an image sensor substrate.

[0002]

2. Description of the Related Art In a conventional solid-state image pickup device, as shown in FIG. 3, a plurality of pixel concave portions are formed in a regular matrix on a wiring layer 4 formed on the surface of a solid-state image pickup device substrate 1 for propagating photoelectric signals. 2 is bored.

A light receiving portion 3 by a photodiode is provided at the bottom of the pixel concave portion 2, and a photosensitive transparent resin (for example, a negative photocurable resin) is filled in the concave portion 2 and the concave portion 2 is formed by pattern exposure. The transparent layer 5 is formed by curing only the resin filled inside and developing and removing the uncured resin.

[0004]

The upper surface of the transparent layer 5 made of transparent resin and filled in the pixel recess 2 is not always flush with the upper surface of the wiring layer 4, and the wiring layer 4 The unevenness is formed between the upper surface of the and.

Since these irregularities hinder the formation of the color filter layer 8 later, conventionally, after the transparent layer 5 is formed, a transparent resin is coated on the upper side of the irregularities to form the flat layer 9. Then, the color filter layers 8 of the red color layer R, the green color layer G, and the blue color layer B are patterned on the flat layer 9 in the portions corresponding to the respective pixel concave portions 2, and the light receiving portion 3 is thereby formed. And color filter layer 8
The distance between and is kept at an ideal constant distance of, for example, less than 4 μm.

For the flattening by the flat layer 9, it is necessary to form the coating film as thick as possible.

However, if the coating film thickness of the flat layer 9 is too thick, the distance between the light receiving portion 3 and the color filter layer 8 becomes, for example, 4 μm or more, and as a result,
The flat layer 9 needs to be formed as carefully as possible because of the occurrence of crosstalk and the deterioration of the sharpness and the color purity, which requires considerable labor in the manufacturing process.

An object of the present invention is to eliminate the unevenness due to the filling of the transparent resin in the concave portion of the pixel, omit the step of coating the flat layer, and efficiently manufacture a good solid-state image pickup device.

[0009]

According to the present invention, a plurality of pixel concave portions 2 formed in a regular matrix in a photoelectric signal wiring layer 4 formed on a surface portion of a solid-state image pickup device substrate 1 and the concave portions 2 are formed.
Is provided with a light-receiving portion 3 and a light-transmissive layer 5 formed by filling the concave portion 2 with a transparent resin, the light-transmissive layer 5 including a first light-transmissive layer 6 and a second light-transmissive layer 7. It is a solid-state imaging device characterized by being constituted by

Further, the present invention is the solid-state image pickup device according to the above-mentioned invention, in which each color filter layer 8 of red color layer R, green color layer G and blue color layer B is provided on the light transmitting layer 5. It is an element.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The solid-state image sensor of the present invention will be described in detail below according to the embodiment shown in FIG.

On the two-dimensional surface of the photoelectric signal wiring layer 4 formed on the surface layer portion of the solid-state image pickup device substrate 1, a plurality of pixel concave portions 2 are provided as matrix-shaped image pickup pixels which are regularly arranged. .

A light receiving portion 3 formed of a photodiode is formed in the bottom of each pixel concave portion 2, and a transparent photosensitive resin is filled in each pixel concave portion 2 and is formed by photo-curing treatment. The transparent layer 5 is formed.

In the solid-state image pickup device of the present invention, the light-transmitting layer 5 includes a lower first light-transmitting layer 6 and an upper second light-transmitting layer 7.
And the upper surface of the upper second light-transmitting layer 7 is substantially flush with the upper surface of the wiring layer 4 due to this two-layer structure.

The solid-state image pickup device of the present invention can be used not only for picking up a monochromatic image but also for picking up a color image.
A color filter layer 8 for color separation for capturing a color image is formed, and a red color layer R, a green color layer G, and a blue color layer B are patterned on the upper surface of each second light transmitting layer 7. There is something.

Each of the color patterns R, G and B of the color filter layer 8 is formed by using a dyeing resin and a dye, and dyeing the dyeing resin in a sequential pattern with a dye mask mask pattern. It can be formed by a dyeing method performed by the above, or a pigment dispersion method performed by a pattern exposure / development process using a pigment dispersion photoresist.

The solid-state image sensor of the present invention is, for example,
It is possible to previously provide a coating layer of silicon dioxide (SiO ₂ ) on the upper surface of the wiring layer 4 by sputtering, and the wiring whose conductivity is imparted by doping (implanting a conductive substance) mainly containing silicon. The affinity (adhesiveness) with the color filter layer 8 for the layer 4 is improved.

Next, specific examples of the solid-state image pickup device of the present invention will be described below in accordance with the manufacturing steps shown in FIGS.

Example 1 First, in FIG. 2A, the step between the light receiving portion 3 in the pixel recess 2 and the upper surface of the wiring layer 4 having the pixel recess 2 formed therein is about 1 μm or more and 1.5 μm. The following is a description of the transparent negative photosensitive resin 16 (for the CCD solid-state image sensor substrate 1 made of a silicon wafer (diameter 10 cm) in which 136 light receiving portions 3 are formed in a matrix. FVR-TP1 containing acrylic resin as the main component
0; Fuji Yakuhin Co., Ltd., spin coater (rotation speed; 12
It was applied to a film thickness of 1.5 μm at 00 rpm).

Subsequently, after drying, the pattern exposure mask 11 in which a light shielding pattern 11a is formed in a portion corresponding to the convex wiring layer 4 of the CCD type solid-state image pickup device substrate 1 is shown in FIG. 2B.
Was exposed to ultraviolet light for 15 seconds at a light intensity of 20 mW / cm ² to photo-cure only the photosensitive resin 16 in the recess 2.

Subsequently, a convex wiring layer 4 is formed with a dedicated developer.
The uncured resin film on the top is removed, and FIG.
As shown in, the transparent first light-transmitting layer 6 was formed in the recess 2.

Next, as shown in FIG. 2D, a transparent negative photosensitive resin 17 (same as above) is applied to the CCD type solid-state image pickup device substrate 1 having the first light transmitting layer 6 formed in the recess 2. FVR-TP10 mainly made of acrylic resin of No. 1; manufactured by Fuji Yakuhin Co., Ltd. using a spin coater (rotation speed: 1200 rpm)
To a film thickness of 1.5 μm.

[0023] Subsequently, after drying, using a pattern exposure mask 11 in the same manner as described above, by the light intensity 20 mW / cm ² 1
The photosensitive resin 17 in the concave portion 2 is exposed to ultraviolet light for 5 seconds.
Only the photocuring is performed, and the uncured resin film on the convex wiring layer 4 is removed with a dedicated developing solution to remove the transparent first film in the concave portion 2 as shown in FIG. 2 The light transmitting layer 7 was formed.

[0024]

According to the solid-state imaging device of the present invention, the recessed portion of the pixel is filled with the light-transmitting layer having a two-layer structure including the first transparent layer and the second transparent layer, and the recessed portion is filled with the transparent layer. The upper surface of the filled translucent layer and the upper surface of the wiring layer are flat and substantially flush with each other, and it is time-consuming to form a flat layer in the conventional manufacturing process of the solid-state imaging device. Can be omitted, troubles due to defective coating of the flat layer can be eliminated, and a good quality solid-state imaging device can be efficiently manufactured.

[Brief description of the drawings]

FIG. 1 is a partially enlarged side sectional view of a solid-state image sensor according to the present invention.

2A to 2E are side cross-sectional views illustrating a manufacturing process of the solid-state image sensor of the present invention.

FIG. 3 is a partially enlarged side sectional view of a conventional solid-state image sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Solid-state imaging element substrate 2 ... Imaging pixel recessed part 3 ... Light receiving part 4 ... Wiring layer 5 ... Translucent layer 6 ... 1st translucent layer 7 ... 2nd translucent layer 8 ... Color filter layer 9 ... Flat layer 11 ... Pattern Exposure mask 11a ... Shading pattern 16, 17 ... Transparent photosensitive resin L ... Incident light

Claims (2)

[Claims] 1. A plurality of pixel recesses 2 formed in a regular matrix in a photoelectric signal wiring layer 4 formed in a surface layer portion of a solid-state imaging device substrate 1, a light receiving portion 3 at the bottom of the recess 2, and the recesses. Two
A transparent layer 5 formed by filling transparent resin therein is provided, and the transparent layer 5 includes a first transparent layer 6 and a second transparent layer 7.
And a solid-state image sensor. 2. The solid-state image sensor according to claim 1, further comprising a colored color filter layer 8 of a red color layer R, a green color layer G, and a blue color layer B on the translucent layer 5.