JPS6078402A - Solid-state color image pickup device and its production - Google Patents

Abstract

PURPOSE:To improve controllability of spectral characteristics with high accuracy and good reproducibility by unitizing color filters and a solid-state image pickup element and forming a part of the color filters as color monitors for measuring the spectral characteristics via a metallic reflecting film pattern on the above-mentioned element. CONSTITUTION:Color filters 5, 6, 7 are united to a solid-state image pickup element 1 and a part of color filters 5, 6, 7 are formed as color monitors for measuring the spectral characteristic on the element 1 via a metallic reflecting film pattern 20. Such solid-state color image pickup device is formed by forming a metallic reflecting film pattern 20 for forming the color monitors 5, 6, 7 to a part on the element 1, then providing the color filters 5, 6, 7 thereon and a picture element part 2. Said device controls the spectral characteristic of the formed color filters while measuring the reflected light with the filters 5, 6, 7 on the pattern 20 as color monitors. The similar operation is repeated with the other color filters as well. The spectral transmission characteristics of the filters 5, 6, 7 are thereby determined with high accuracy and good reproducibility. Controllability is thus improved and the good color characteristic is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color solid-state imaging device and a method of manufacturing the same. More specifically, the present invention provides a method for easily and accurately measuring the spectral characteristics of the formed color filter when the color filter is directly formed on a solid-state image sensor, and an element structure that makes it possible. It is.

Conventional configuration and its problems Generally, in order to colorize a solid-state image sensor.

It is necessary to attach color filters of multiple colors to the front of the pixel section of the device. However, using a method of directly forming color filters on the device instead of bonding them, although the alignment accuracy of the color filters is greatly improved, it is difficult to measure the spectral characteristics, and therefore it is difficult to control the spectral characteristics (a1id is not easy). .

For example, methods for monitoring the spectral characteristics of a color filter formed on an element include forming a color filter on a glass plate together with the element and indirectly measuring the spectral characteristics using this as a color monitor. , a method is used in which a color filter formed on an element is measured by direct reflection spectrophotometry and calculation processing is performed to determine the spectral characteristics.

However, in the method of forming color filters on a glass plate, since the uneven shape of the substrate surface is different from that of the element, the thickness of the color filter at the time of formation is large and it is not possible to obtain effective spectral characteristic data.

On the other hand, in the method of directly measuring the color filter formed on the device, an apparatus as shown in Figure 1 is used to directly measure the spectral characteristics of the color filter on the silicon photodiode by reflection photometry, and calculate the required transmission spectrometry. A method was used to obtain the characteristics. In this method, spectrophotometry is performed on the light that is reflected back from the Si photodiode surface, but since the visible light reflectance of Si is generally low, the interference of the color filter constituent films is large, resulting in accurate measurements. Reflection spectroscopy could not be performed. Reflection photometry data is shown in FIG. 2, but it is clear that it is not easy to determine the transmission spectral characteristics (FIG. 3) from this data.

In FIG. 1, 1 is a solid-state image sensor, 2 is a photodiode, 3 is a wiring, 4 is a passivation film, and 6 is a photodiode.
Hanan (Cy) filter, 6 is a yellow (7) filter, 7 is a transparent color separation film, 8 is a bonding pad, and constitutes a color solid-state image sensor, 9 is an objective lens,
10 is a filter, 11 is a light source, 12 is a collimator, 1
3 is the slit, 14 is the reflector%, 15 is the eyepiece, 1
6 is a slit, 17 is a detector, and 18 is a concave diffraction grating, which constitutes a reflection spot spectrometer B.

Purpose of the Invention In view of the shortcomings of the conventional color filter spectral characteristic monitoring method described above, it is an object of the present invention to reduce interference of color filter constituent films as much as possible even when a color filter is formed directly on a solid-state image sensor. However, it is an object of the present invention to provide an element structure that allows the spectral characteristics of a color filter to be measured with higher precision, and a manufacturing method thereof.

Structure of the Invention The present invention relates to a colored solid-state image sensor and a method for manufacturing the same, and in particular, when forming a color filter directly on a solid-state image sensor, the spectral characteristics of the color filter can be measured with high precision. In order to achieve this, the color tints are formed on a pre-fabricated metal reflective film pattern with good light reflectivity.

DESCRIPTION OF THE EMBODIMENTS When directly forming color filters and filters on a solid-state image sensor, a metal reflective film pattern 2o is formed on the photodiode 2 in advance as shown in FIG. 4 before forming the color filter. Color filters formed on reflective film patterns (
The spectral characteristics of a color monitor (hereinafter referred to as a color monitor) are measured as one reflection spectral characteristics. In Fig. 4, the color monitor is formed on the photodiode at the periphery of the pixel portion via a reflective film pattern 2o made of a thin film, which allows the color filter spectral characteristics of the effective pixel portion to be adjusted with higher precision. However, if very high precision is not required, a color monitor may be formed in an empty space in the drive section without destroying pixels on one peripheral edge. next.

This reflection spectral data is subjected to computer processing to obtain transmission spectral characteristics when formed on a glass plate as shown in FIG.

At this time, the density of the color filter is controlled so as to have predetermined spectral characteristics while observing the transmission spectral characteristics.

FIG. 5 shows the reflection spectral characteristics obtained by the element structure of the present invention, and it is clear that the interference of light is significantly reduced compared to FIG. 2. In other words, by using the method of the present invention, when forming a color filter directly on a solid-state image sensor, it is possible to measure the spectral characteristics of the color filter with higher precision, and as a result, the spectral characteristics of the color filter can be measured with higher accuracy. controllability is greatly improved.

Thereafter, by forming color filters of other colors using the same method, a colored solid-state imaging device can be manufactured.

Effects of the Invention With the colored solid-state image sensor structure of the present invention, even when a color filter is formed directly on the element, the transmission spectral characteristics of the color filter can be improved with high degree of separation and good reproducibility. The controllability of the spectral characteristics of the filter is improved, and as a result, the color characteristics of the color solid-state image sensor can be significantly improved.

[Brief explanation of drawings]

Figure 1 is a diagram showing the concept of the reflection photometry method for measuring the spectral characteristics of color filters, which has been used in the past. Part A is an enlarged cross section of the pixel part of a color solid-state image sensor, and part B is a diagram for measuring the spectral characteristics of color filters. A schematic diagram of the system, Fig. 2 is a reflection spectral characteristic diagram of a color filter obtained by the conventional method, Fig. 3 is a diagram showing custom transmission spectroscopy, and Fig. 4 explains the element structure of an embodiment of the present invention. FIG. 5 is a cross-sectional view of the device showing the color monitor and the metal reflective film pattern at the periphery of the blank pixel, and is a diagram showing the reflection spectral characteristics obtained from the device having the structure of the present invention. 20...Metal reflective film pattern. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 5

Claims (3)

[Claims] (1) A color filter is integrated with a solid-state imaging device consisting of a pixel section and a drive section, and a part of the color filter is formed on the device via a metal reflective film pattern as a color monitor for measuring spectral characteristics. A color solid-state imaging device characterized by: (2) The colorized solid state according to claim 1, wherein the color monitor for measuring spectral characteristics is formed via a metal reflective film pattern formed on a photodiode at the periphery of the pixel portion. Imaging device. (3) Forming a metal reflective film pattern for forming a color monitor on a part of the solid-state image sensor consisting of a pixel part and a drive part, and forming a color filter on the metal reflective film pattern and on the pixel part. , a step of controlling the spectral characteristics of the color filter to be formed while performing reflection photometry using the color filter on the metal reflective film pattern as a color monitor, and thereafter forming color filters of other colors in the same manner and measuring the spectral characteristics. - A method for manufacturing a color solid-state imaging device characterized by repeating a control process.