JPH04181784A - Semiconductor element and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a semiconductor element having a light absorption film for reducing light to be emitted on a semiconductor substrate by providing the film made of organic resin containing light absorption material above the substrate so as to shield the light irradiated to the substrate. CONSTITUTION:In order to reduce a reflected light to a substrate by a metal film 4, a light absorption film 2 made of organic resin containing light absorption material is provided above the film 4. Thus, the film 2 is provided above the film 4 to reducing a reflected light from the film 4, thereby reducing an error signal component of an output. Thus, reflection of the irradiated light from the surface of a chip to the semiconductor substrate can be suppressed. Even if a strong and bright light source is moved to any position of an element, generation of a quasi-signal caused by the light source can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use] The present invention relates to a semiconductor device on which a photoelectric conversion element is formed and a method for manufacturing the same.

[Prior Art] Conventionally, in general devices formed on a semiconductor substrate, the device is encapsulated in black molding resin as a whole because electrons or holes are generated in the semiconductor substrate by irradiation light, causing the device to malfunction. was.

In addition, conventional photoelectric conversion elements formed on semiconductor substrates cannot be encapsulated in black mold resin because they use light, and a light-shielding film is provided above the semiconductor substrate except for the light-receiving area, and the entire structure is transparent molded. It was sealed in resin. However, the light reflected by this light-shielding film is reflected again on the surface of the encapsulating resin and irradiates the semiconductor substrate, causing an erroneous signal. Therefore, by making the encapsulating resin thicker, the reflected light from the light-shielding film is directed toward the periphery of the chip, so that the semiconductor substrate located in the center is not irradiated, and instead of being encapsulated in resin, it is possible to package it in a hollow state using ceramic or other materials. Was.

[Problems to be Solved by the Invention] However, if the encapsulating resin is made too thick, the semiconductor element is likely to crack due to stress, air bubbles are generated in the resin, and foreign matter gets mixed into the resin, which makes manufacturing difficult. In addition, to overcome this drawback, there is a method of reducing the thickness of the encapsulating resin to the conventional level and then attaching a substance with a refractive index similar to that of the encapsulating resin to the surface of the encapsulating resin. In this case, the same effect as encapsulating with thick resin can be obtained, but it is necessary to bond each element individually, making it inefficient and unsuitable for mass production.Also, using ceramic packages, etc. However, there were disadvantages such as the overall size of the device and the expensive package.

Therefore, it is an object of the present invention to provide a semiconductor element equipped with a light absorption film that can significantly reduce the light irradiated onto a semiconductor substrate, and to manufacture a semiconductor element by producing the light absorption film at low cost and with excellent mass productivity. The purpose is to provide a method.

[Means and effects for solving the problems] That is, the present invention provides a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate, in which a light-absorbing material is provided above the substrate in order to block light irradiated to the substrate. A semiconductor device characterized by being provided with a light absorption film made of an organic resin containing
Another method of manufacturing a semiconductor device is to provide a light-absorbing film by applying a photo-reactive organic resin containing a light-absorbing material and then exposing and developing the film.

The present invention also provides a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate and a highly reflective metal film is provided above the substrate for blocking light irradiated onto the substrate, in which the substrate is formed by the metal film. A semiconductor element characterized in that a light absorbing film made of an organic resin containing a light absorbing material is provided above the metal film in order to reduce light reflected from the metal film; This method of manufacturing a semiconductor device is characterized in that a light-absorbing film is provided by applying a reactive organic resin, followed by exposure and development.

Conventionally, as shown in FIG. 2 (a diagram showing a molded state), light enters the sensor light receiving section 5 through a transparent mold resin. However, since the light hits the entire surface of the chip, the metal film 4 for shielding light is also irradiated. This light is reflected by the light-shielding film, and then a part of it is reflected again by the surface of the molding resin, as shown by the broken line, and then enters the light receiving section. In this case, the output is ■ as shown in Figure 5 (signal reading diagram of the photoelectric conversion element). Since the amount changes depending on the intensity of the input light, the signal output becomes larger than the original incident amount due to the incidence of reflected light, and the output signal becomes high.

In contrast, in the present invention, by providing a light absorption film on the light shielding film 4, it is possible to reduce the amount of reflected light from the light shielding film, thereby reducing the erroneous signal component of the output. The light shielding film is the third
Diagram (Plan view showing a molded state with a light absorption film provided)
It is formed so as to surround the light receiving section, and a light absorption film may be provided above the light receiving section within the range where the reflected light reaches the light receiving section.

In the present invention, examples of the photoreactive organic resin include polyimide, acrylic, polyamide, and the like to which a photopolymerizing agent is added. Examples of light-absorbing materials include carbon, general pigments, and dyes. A light absorbing material is dispersed or dissolved in the organic resin and dyed to form a light absorbing film. Commercially available products include OK (acrylic, carbon) manufactured by Fuji Hunt Co., Ltd., which has photoreactivity, and DARC, manufactured by Brewer Science, Inc. (USA), which does not have photoreactivity.

In order to form a light-absorbing film in the present invention, after coating the organic resin above the semiconductor substrate by spin coating using a spin coater or the like, a highly reflective metal film (hereinafter referred to as a light-shielding metal film) is provided below except for the light receiving area. A desired light-absorbing film can be formed above the substrate by patterning the film. Since the organic resin for forming the light-absorbing film has photoreactivity, pattern formation is performed by aligning masks, exposing, and developing.

[Example] Next, the present invention will be explained by giving examples.

A resin in which carbon is dispersed is applied using a spin coater onto a semiconductor substrate on which photoelectric conversion elements (BASIS, COD, etc.) are formed. Next, this film is formed into a desired pattern using photolithography technology.

In this case, since the resin has photoreactivity, a pattern is formed by mask alignment, exposure, and development.

After pattern formation, the resin is cured at a predetermined temperature.

FIG. 1 is a sectional view of a state in which an element on which a light absorption film is formed is encapsulated in a transparent mold resin. In the figure, 1 is a transparent mold resin, 2 is a light absorption film, 3 is a passivation film, 4 is a light-shielding metal film, 5 is a light receiving part, 6 is a wiring, and 7 is an interlayer insulating film.

Further, the reflection spectral characteristics obtained at that time are shown in FIG. In the same figure, the solid line is the reflection spectral characteristic when there is no light absorption film, and the broken line is the reflection spectral characteristic when the light absorption film is provided.

Further, the light absorption film according to the present invention does not need to be provided on the passivation film. That is, it is also possible to form it directly in contact with the light-shielding metal film. Also in this case,
A passivation film can be formed on the light absorption film.

In addition, by forming a light absorbing film immediately after forming a light shielding metal film, patterning it, and etching the underlying light shielding metal film using this as a mask, a desired light shielding film can be formed using Selfa Line.

Furthermore, if this light-absorbing film sufficiently absorbs light over a wide range of wavelengths, the light-shielding metal film becomes unnecessary, and as a result, the capacitance of the entire device decreases, making it possible to increase the output and speed of the device.

[Effects of the Invention] As explained above, by forming a light-absorbing film above a highly reflective light-shielding metal film, it is possible to suppress the reflection of irradiated light from the chip surface to the semiconductor substrate. . As a result, no matter where a strong and bright light source comes from with respect to the element, the generation of condensation signals caused by the light source can be suppressed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a state in which an element on which a light absorption film is formed is encapsulated in a transparent mold resin according to the present invention. FIG. 2 is a sectional view showing a conventional device encapsulated in a transparent mold resin. FIG. 3 is a plan view showing an example of a state in which an element on which a light absorption film is formed is encapsulated in a transparent mold resin according to the present invention. FIG. 4 is a circuit diagram of an example of the photoelectric conversion element of the present invention. FIG. 5 is a signal reading diagram of an example of the photoelectric conversion element of the present invention. FIG. 6 is a diagram showing reflection spectral characteristics. 1...Transparent mold resin, 2...Light absorption film, 3
... Passivation film, 4... Light-shielding metal film, 5.
... Light receiving section, 6... Wiring, 7... Interlayer insulating film. Agent Patent Attorney Jo Taira Yamashita Figure 1 (#U) Figure 2 Figure 3 Figure 4 (Elμ illusion

Claims (1)

[Claims] 1. In a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate, a light absorbing material made of an organic resin containing a light absorbing material is placed above the substrate to block light irradiated onto the substrate. A semiconductor element characterized by being provided with a film. 2. In a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate and a highly reflective metal film is provided above the substrate for blocking light irradiated to the substrate, light reflected by the metal film onto the substrate A semiconductor device characterized in that a light absorbing film made of an organic resin containing a light absorbing material is provided above the metal film in order to reduce the amount of light absorbed. 3. In a method for manufacturing a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate, an organic resin containing a light-absorbing material and having photoreactivity is placed above the substrate to block light irradiated onto the substrate. 1. A method for manufacturing a semiconductor device, comprising applying a light-absorbing film, followed by exposure and development. 4. A method for manufacturing a semiconductor device in which a photoelectric conversion element is formed on a semiconductor substrate and a highly reflective metal film is provided above the substrate for blocking light irradiated onto the substrate, in which the metal film is applied to the substrate. In order to reduce reflected light, a light-absorbing film is provided above the metal film by coating an organic resin containing a light-absorbing material and having photoreactivity, followed by exposure and development. A method for manufacturing semiconductor devices. 5. The method of manufacturing a semiconductor device according to claim 3 or 4, wherein the coating is performed by spin coating.