JP2001094084A - Solid state color imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a solid state color imaging device comprising a color filter and a convex lens formed for the light receiving element in the sensor in which photosensitivity can be enhanced without causing any trouble even in case of a solid state imaging device where a light shielding layer is present partially on the central plane of the light receiving element. SOLUTION: A ring type convex lens is provided on a light receiving element in order to avoid condensation of light onto a light shielding layer present in the center of the light receiving element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color solid-state image pickup device (charge-coupled device:
CCD).

[0002]

2. Description of the Related Art Conventionally, when a color solid-state image sensor is manufactured, a color filter is formed on a wafer on which a circuit of the solid-state image sensor is formed before cutting into individual chips. Thereafter, chips of the individual color solid-state imaging devices are cut out, embedded in a member on which a peripheral circuit is appropriately formed, and electrically connected to each other to obtain a completed product. Peripheral member layers other than the color separation filters are also formed in a wafer state.

As shown in FIG. 2, a color solid-state imaging device of this type includes a plurality of light-receiving elements 2 embedded in a substrate 1 made of silicon or the like, and a red light-receiving element provided on the light incident side of each light-receiving element 2. , Green and blue color filter layers 7 are known as main components. In addition, the surface is flattened by forming the lower smoothing layer 5 made of a transparent material before forming the black matrix 6 and the color filter layer 7 which are provided at the portions corresponding to the gaps of the light receiving element 2, Techniques for improving their shapes are also used.

[0004] Here, quality issues required for the color solid-state imaging device include improvement of light sensitivity and prevention of crosstalk. For this purpose, usually, as shown in FIG. 3, a convex lens-shaped member (group of convex lens bodies 9) is provided on a color filter via an overcoat layer 8 made of a transparent resin.
The image light of the external world is condensed and incident on the light receiving element 2 on the solid-state imaging device. Thereby, the improvement of the light sensitivity is achieved.

However, some light-receiving elements of solid-state imaging devices have a light-shielding electrode layer partially present on the central surface of the element. In this case, the above-mentioned conventional convex lens body is placed on a color filter. In this case, since incident light concentrates on the light-shielding electrode layer, the conventional configuration in which a color filter and a convex lens body are combined cannot be adopted.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a light-receiving element in which a light-shielding electrode layer is partially formed on the central surface. It is an object of the present invention to provide a color solid-state imaging device capable of improving the light sensitivity without causing the above-mentioned problem, while employing a convex lens body on a color filter even in the existing types of solid-state imaging devices.

[0007]

According to the present invention, there is provided a color solid-state imaging device having at least a color filter and a convex lens body formed on a light-receiving element of a solid-state imaging device. A color solid-state imaging device is characterized in that a ring-shaped convex lens body is provided on a light receiving element so as to prevent light from condensing on the light receiving element.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below together with an embodiment. As shown in FIGS. 1A and 1B, the color solid-state imaging device according to the present invention includes at least a silicon substrate 1 and a plurality of light receiving devices 2 arranged in a matrix in the silicon substrate 1. The light receiving element 2
A central portion and an electrode layer 3 extending from the pixel region to the outside of the pixel region; a transparent lower smoothing layer 5 provided on the silicon substrate 1 and the electrode layer 3; A lattice-like black matrix 6 composed of chromosomes stained with a black dye provided at a portion corresponding to the gap between each light receiving element portion, and also on the lower smoothing layer 5 and corresponding to each light receiving element portion A red, green, blue (R, G, B) color filter layer 7 provided on the portion; a transparent overcoat layer 8 provided on the black matrix 6 and the color filter layer 7; The main part of the light-receiving element 8 is composed of a ring-shaped convex lens body 9a provided so as to prevent light from condensing on the light-shielding electrode layer existing in the central part of the light receiving element. In FIG. 1A, the black matrix 6 and the like are omitted for easy viewing.

In the above structure, before the lower smoothing layer 5 is provided, the filling layer 4 may be provided so as to fill the concave portion of the silicon substrate 1 around the portion where the light receiving element 2 is provided. May be asked.

The formation of the color solid-state image pickup device having this structure was performed according to the following procedure. Silicon substrate 1
A plurality of light receiving elements 2 are formed in a matrix at a pitch of, for example, about 10 μm by a conventional method, and an electrode layer 3 extending from the center of the formed light receiving element 2 to the outside of the pixel area is formed of aluminum. did.

Next, the filling layer 4 is filled with a photosensitive acrylic resin "FVR" manufactured by Fuji Pharmaceutical Co., Ltd. so that the concave portion around the portion where the light receiving element 2 is formed in the silicon substrate 1 is filled.
Using “−10 G”, pattern exposure was performed at 20 mW / cm ² for 15 seconds to form a film having a thickness of 2.5 μm.

Further, a lower smoothing layer 5 was formed from above the filling layer 4 using the same material as the above-mentioned filling layer 4 to a thickness of 2.0 μm under the same conditions as in the entire surface exposure.

Next, a lattice-like black matrix 6
Is formed by patterning a chromosome and dyeing it with a black dye, and then forming a color filter layer 7 with a pigment-dispersed colored photosensitive resist to a thickness of 1.0 to 1.4 μm by a conventional method, red,
Each color of green and blue was sequentially and repeatedly formed. On top of that, a transparent overcoat layer 8 was formed according to a conventional method. The color filter layer 7 can be formed by a dyeing method or the like.

Next, a photosensitive resin material "MFR345" manufactured by JSR Co., Ltd.
And above the portion corresponding to the position of each light receiving element 2,
An exposure time of 190 m using a pattern mask so as to form a ring-shaped pattern that avoids condensing light at the end of the light-shielding electrode layer located at the center of the light receiving element.
The pattern was formed under the conditions of 200 ° C. and 180 seconds for hardening and baking to obtain a ring-shaped convex lens body 9a. In the course of this baking, the cross-sectional shape of each of the patterned ring-shaped formed bodies became a gentle mountain shape, resulting in a ring-shaped convex lens body having a condensing function. The height (film thickness) up to the apex of the convex lens body 9a was about 1.5 μm.

[0015]

According to the present invention, even in a solid-state imaging device of a type in which a light-shielding electrode layer is partially present on the central surface of a light-receiving device, a solid-state imaging device having a convex lens body having the above-described shape on a color filter is provided. The light sensitivity of the element can be improved without causing a problem due to the incident light being condensed on the light-shielding electrode layer on the central surface of the light receiving element. Further, most of the incident light is efficiently condensed on the light receiving element portion in the corresponding pixel, and light leakage (crosstalk) to a portion other than the corresponding pixel is reduced, so that there is an effect of preventing color mixing.

[0016]

[Brief description of the drawings]

FIG. 1A is a plan view of one pixel of a color solid-state imaging device of the present invention, and FIG. 1B is a cross-sectional view thereof.

FIG. 2 is a cross-sectional view illustrating an example of a conventional color solid-state imaging device.

FIG. 3 is a cross-sectional view illustrating an example of a conventional color solid-state imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon base 2 Light receiving element 3 Electrode layer 4 Filling layer 5 Lower smoothing layer 6 Black matrix 7 Color filter layer 8 Overcoat layer 9, 9a Convex lens body

Claims (1)

[Claims] In a color solid-state imaging device having at least a color filter and a convex lens body formed on a light-receiving device of a solid-state imaging device, light is not focused on a light-shielding electrode layer located at a central portion of the light-receiving device. A color solid-state imaging device, wherein a ring-shaped convex lens body is provided on a light receiving element.