JPS6325602A - Color filter for color solid-state image pickup element - Google Patents

Abstract

PURPOSE:To develope uniformly a required color with inexpensive mass production and to improve stability and reliability of color development by selectively implanting metal ions to the surface of a sapphire substrate and executing heat treatment to develope the color. CONSTITUTION:When a window part 4 is opened on the sapphire substrate 1 with 0.3mu thickness by photoresist, about 1X10<17>cm<-2> Co ions are implanted and the whole surface is heated for 3hr at about 800 deg.C, green is developed on the ion implanted part 2. Then, the window part 4 is changed, metal ions developing red and blue constituting the three primary colors are implanted and heat treatment is executed to develope the colors. A color filter 10 for a color solid-state image pickup element arranging three colors 2R, 2G, 2B like stripes can be obtained on the substrate 1 by forming the window part 4 like slits. Thereby, a required color can be uniformly and stably developed by the selection of the metal ions without a change in the passage of time and the reliability of color development can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color filter for a color solid-state image sensor used as a color filter for a solid-state image sensor such as a color video camera.

[Summary of the invention]

The present invention enables mass production at low cost by selectively implanting metal ions into the surface of a sapphire substrate and applying heat treatment to develop color, which can be used as a filter for color solid-state imaging devices such as color video cameras. It is an object of the present invention to provide a color filter for a color solid-state image sensor that has excellent ε conversion properties and stability.

[Conventional technology]

In recent years, color video cameras for business and home use have become popular.
Is the image pickup tube equipped with a charge-coupled device (CCD), a so-called color solid-state image sensor, which converts the brightness and darkness of each part of the object to be photographed into electrical signals proportional to the brightness and darkness of each part of the object to be photographed? (-7 is now used.

By the way, in a color solid-state image pickup device used in a color video camera, in order to perform color densification, it is necessary to laminate or paste a color filter for the first color solid-state image element on the surface of the device, which separates the color information of the subject. be.

The above-mentioned color filters for solid-state imaging elements are generally formed by coating a colored organic material film such as gelatin on a glass substrate, and then partially dyeing the organic material film using photoresist forming technology. It is manufactured by repeating this process to create a three-primary color filter.

However, since such color filters are made of colored organic materials such as gelatin, they have extremely low heat resistance, and are susceptible to deterioration, resulting in changes in filter characteristics over time.
There are various problems such as difficulty in achieving uniformity when fixing dyes to gelatin.

In addition, the use of interference filters as color filters is being considered, but this requires extremely high precision in the thickness of the interference film, making it difficult and expensive to manufacture. It is not practical as a color filter.

[Problem that the invention seeks to solve]

As mentioned above, when color filters are made from organic materials, there are issues to be solved in terms of stability and reliability due to the characteristics of the material, and in the case of interference filters, there are issues to be resolved in terms of manufacturing and cost. There is a problem.

The present invention was proposed to solve the above-mentioned conventional problems, and aims to provide a color filter for a color solid-state image sensor that can be mass-produced at low cost and has excellent reliability and stability. purpose.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention is characterized in that metal ions are selectively implanted into the surface of a sapphire substrate and then heat treated to develop color.

[Effect]

The color filter of the present invention uses a sapphire substrate, which is an extremely chemically and thermally stable material, and therefore has excellent stability without changing over time.

Furthermore, since the color filters are colored using the technically well-established method of metal ion implantation, reliability and productivity are significantly improved.

Furthermore, the desired color can be easily obtained by selecting the metal ion.

〔Example〕

The present invention will be explained below.

The present inventor completed the present invention by focusing on the phenomenon that, by implanting predetermined metal ions onto a sapphire substrate and subjecting the substrate to heat treatment, the portion into which the metal ions are implanted develops a predetermined color.

Regarding the coloring phenomenon of the metal ion implanted part, Saito et al.
ed Physics (Giabanese Journal of Applied Physics) 24 (1985)
880) reported that, for example, metal ions such as Fe", Go", etc. were implanted onto a sapphire substrate at a concentration of 1X10" to 3X10" ions/C.
It is reported that when heat treated at 0° C. for 3 hours, the areas into which these metal ions were implanted developed a yellowish-brown or bright blue color, respectively.

As a result of further investigation by the present inventor, it was confirmed that other metal ions also develop colors as shown in the following table, for example.

(Note: The concentration represents the ion implantation concentration, 3000
This is the concentration when injecting to the depth of a person. ) Therefore, in the present invention, the sapphire substrate is selectively colored by ion implantation of the aforementioned metal ions, and this is used as a color filter.

In fact, the following method may be used to manufacture a color filter for a color solid-state image sensor using such a phenomenon.

First, as shown in FIG.
Selectively open windows using O□, photoresist (3), or the like. And the window part (4) formed in this way
As shown in Fig. 2, when producing a color filter composed of, for example, three primary colors using a normal ion implantation method, co After that, heat treatment is performed at a temperature of about 800° C. for about 3 hours using an electric furnace or the like.

By performing the above-described processing, the Co'' ion implanted portion (2) develops a green color.

Next, the window portion (
The position of 4) is changed, and metal ions that produce red and blue, which constitute the three primary colors, are implanted there, and heat treatment is performed to cause the metal ion implanted portion (2) to develop each color.

Here, if the window part (4) is made into a slit shape, for example, the third
As shown in the figure, there is a red part 2R on the sapphire substrate (1).
, the green part 2G and the blue part 2B are colored in a stripe pattern,
It becomes a striped color filter.

Of course, the shape of the color scheme formed on the sapphire substrate (1) is not limited to this, and may be formed in a mosaic shape that is substantially like the eyes of the base.

The shape of the above color scheme is simply determined by the shape of the window (4) provided in the CVD5 i O2, photoresist (3), etc. The window (4) can be formed very easily, and It is also possible to easily implant metal ions into the window portion (4).

Metal ions that develop a predetermined color are injected into the window portion (4) thus formed, and heat treatment is performed to develop the metal ion implanted portion (2) into a desired color solid-state image sensor color filter (10). Become.

Note that in this example, heat treatment is applied immediately after metal ion implantation to develop color for each metal ion, but heat treatment is performed after several types of metal ions that produce the desired color have been implanted in advance, and the color is created by heat treatment at -degrees. It may also be manufactured to serve as a filter.

When producing a color filter composed of complementary colors, the same method as when producing a color filter of three primary colors may be used. For example, Fe" ions are irradiated with an energy of about 4QQkeV at about I x 10 "cm-". When the Fe' ions are implanted and heat treated at a temperature of about 800° C. for about 3 hours in an electric furnace or the like, the Fe' ion implanted portion (2) develops a yellow color.

The color filter (10) for a color solid-state imaging element produced in this way is very small, measuring about 1/4 to 2/3 inch, and therefore has a size of about several inches (2 to 4 inches). It is also possible to obtain a large number of color solid color filters (10) for color solid-state fii and image elements at once by preparing one and dividing it into predetermined sizes.

A color solid-state imaging device can be obtained by adhering a color filter as described above to the surface of the solid-state imaging device.

〔Effect of the invention〕

As described above, the color filter for a color solid-state image element of the present invention is produced by injecting metal ions exhibiting a predetermined color onto a sapphire substrate using an ion implantation method and heat-treating the sapphire substrate under predetermined conditions. , a color filter.

Therefore, since the color filter of the present invention uses a sapphire substrate which is extremely chemically and thermally stable, it has excellent stability without being subject to change over time.

Furthermore, since a technically established method called metal ion implantation is used, its controllability, uniformity of color development, and reliable φR properties are high.

Furthermore, since it is possible to produce a large filter at a time and then divide it to obtain a filter of a desired size, productivity is excellent.

Furthermore, depending on the predetermined conditions and selection of metal ions,
Since a desired color can be easily obtained, color filters can be easily mass-produced at low cost.

[Brief explanation of drawings]

1 and 2 are enlarged sectional views of main parts showing the manufacturing process of the color filter for a color solid-state image sensor according to the present invention. Each process is shown below. FIG. 3 is a schematic plan view showing an example of a color filter for a color solid-state image sensor. 1...Sapphire substrate 2...Metal ion implantation portion 10...Color filter for color solid-state imaging device Patent applicant Sony Corporation representative Patent attorney Kodo Koike Tamura To Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A color filter for a color solid-state imaging device, characterized in that metal ions are selectively implanted into the surface of a sapphire substrate and colored by heat treatment.