JPS62190871A - Manufacture of color solid-state image pickup device - Google Patents

Abstract

PURPOSE:To improve the manufacturing yield of a color solid-state image pickup device by forming a color mixture preventive film formed between color patterns and the protective film of the unit or inorganic thin films, and selectively etching the inorganic film on a wire bonding pad electrode to reduce photolithographic steps for opening a wire bonding hole to one processing. CONSTITUTION:A silicon oxide film is formed as an inorganic thin film by a photo-chemical vapor deposition method as an intermediate film 107b, a gelatin film is formed on a predetermined P-N junction photodiode, and dyed with predetermined dye such as blue dye to form a colored film 106B. Thereafter, to protect a color solid state image pickup unit, a silicon oxide film is formed as an inorganic thin film by a photo-chemical vapor deposition method as a protective film 108. Then, the film 108 is coated with a photoresist to form a photoresist pattern 109 in which only the photoresist on a pad electrode 104 for wire bonding is removed. The silicon oxide film on the electrode 104 is removed, and the pattern 109 is eventually removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a color solid-state imaging device.

2. Description of the Related Art A conventional method for manufacturing a color solid-state imaging device will be described with reference to the drawings.

FIG. 2 shows a step-by-step process for manufacturing a conventional color solid-state imaging device.

First, selective diffusion, etching, opening, etc. are performed on a P-type silicon substrate 1 by a known predetermined method to provide an N-type region necessary for a solid-state imaging device, and a PN junction photodiode 2 is formed.
．． Form the source/drain n+ layer 3 of the output circuit, open a contact hole in the interlayer insulating film 4, deposit an M film,
pattern, and connect one side through the contact hole.
A wire bonding pad electrode S is formed, which is connected to the positive layer 3 and whose other end extends onto the interlayer insulating film 4 .

(Fig. 2a) Next, an acrylic photosensitive resin is applied to protect the solid-state imaging device and to even out the unevenness of the surface, and the resin film on the wire bonding pad electrode is coated using the photorin method. is removed, and a passivation film 7 having bonding holes 6 is formed.

After that, a photosensitive gelatin is applied as a dyed film, and the gelatin film is left only on the predetermined PN junction photodiode by photolithography, and the gelatin film is dyed with a predetermined dye, such as a red dye, to form a colored film 8R. do. Further, the above-mentioned acrylic photosensitive resin is applied as a resist dye between the colored films, and the resin film on the wire boarding pad electrode is removed by the photorin method, and the intermediate film 9a with the bonding holes 6 formed therein is removed. form. (FIG. 2b) Next, in the same manner as above, a gelatin film is formed on a predetermined PN junction photodiode and dyed with a predetermined dye, such as a green dye, to form a colored film 8G. Thereafter, an intermediate film 9b having wire bonding holes 6 is formed using an acrylic photosensitive resin for resist dyeing. Furthermore, a gelatin film is formed on a predetermined PN junction photodiode and dyed with a predetermined dye, such as a blue dye, to form a colored film 8B. After that, the above-mentioned acrylic photosensitive resin is applied to protect the color solid-state imaging device.
The resin film on the wire bonding pad electrode is removed by photolithography to form a protective film 10 with bonding holes 6 formed therein. (Fig. 2C) Problems to be Solved by the Invention However, with the above configuration, half of the six photolithography steps in the color filter manufacturing process are required to open the bonding holes 6, and the manufacturing process is delayed. Reducing the number of photolithography processes in order to increase yields has become a problem to be solved in order to put color solid-state imaging devices into practical use.

The present invention has been made to solve these problems, and provides a method for manufacturing a color solid-state imaging device that can reduce the number of photolithography steps for forming bonding holes to one.

Means to Solve the Problems The method of manufacturing a color solid-state imaging device of the present invention includes forming a passivation film, an intermediate film, and a protective film using inorganic thin films to protect the solid-state imaging device and flatten surface irregularities. Then, a photoresist is formed on the top part only on the wire bonding pad electrode part by a photolithography process, and the inorganic thin film on the wire bonding pad electrode part is removed by an etching method using the photoresist as a mask. has been done.

Function: With this configuration, the film on the pad electrode portion for wire bonding can be removed all at once in a single photolithography process, and unlike the conventional method, the film on the pad electrode portion for wire bonding can be removed at once. Since it is no longer necessary to remove the molecular resin film by photolithography every time it is formed, it is possible to reduce the number of steps.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows step-by-step a method for manufacturing a color solid-state imaging device according to an embodiment of the present invention.

First, selective diffusion, etching, opening, etc. are performed on the P-type silicon substrate 100 by a known predetermined method to provide an N-type region necessary for a solid-state imaging device, and a P-N junction photodiode 1o1. N+ layer 10 of source and drain of output circuit
2 is formed, a contact hole is opened in the interlayer insulating film 103, At is deposited and patterned, one side is connected to the n+ layer 102 through the contact hole, and the other side is extended onto the interlayer insulating film 103. A wire bonding pad electrode 104 is then formed. (Fig. 1-a) Next, in order to protect the solid-state imaging device and to flatten the surface unevenness, a silicon oxide film is grown as a passivation film 10 by normal pressure vapor phase chemical growth.
Form as 5.

Next, photosensitive gelatin is applied as a dyed film, and the gelatin film is left only on the predetermined PN junction photodiode by photolithography, and the gelatin film is dyed with a predetermined dye, such as red dye, to form a colored film 1o6R. do. Next, an inorganic thin film is formed.

Gelatin membranes do not have good heat resistance, and usually have a temperature limit of 200 degrees. Therefore, when forming, for example, a silicon oxide film as an inorganic thin film, thermal oxidation, normal pressure vapor phase chemical growth, and reduced pressure vapor phase chemical growth cannot be used because the temperature exceeds the heat resistance limit.

Therefore, in the present invention, a photovapor phase chemical growth method is used as a method for forming an inorganic thin film within the heat-resistant limit temperature. The optical vapor phase chemical growth method allows growth at temperatures from 50 degrees to 200 degrees, and can form silicon oxide films, silicon nitride films, aluminum films, and the like.

In this example, a silicon oxide film was formed as an inorganic thin film by a photovapor phase chemical growth method to form an intermediate film 107a.

The formation temperature at this time was 200°C, which did not affect the gelatin film. (FIG. 1-b) Next, in the same manner as above, a gelatin film is formed on a predetermined PN junction photodiode and dyed with a predetermined dye, such as a green dye, to form a colored film 106G. Next, a silicon oxide film is formed as an inorganic thin film using a photochemical vapor deposition method, and the intermediate film 10 is
7b. Further, a gelatin film is formed on a predetermined PN junction photodiode and dyed with a predetermined dye, such as a blue dye, to form a colored film 106B.

After that, in order to protect the color solid-state image sensor, a silicon oxide film was formed as an inorganic thin film using photochemical vapor deposition.
A protective film 108 is used. (Figure 1-〇) Next, the protective film 10
8, a photoresist pattern 109 is formed by removing only the photoresist on the wire bonding pad electrode 104 by a photorin method. (FIG. 1-d) Next, using the photoresist pattern 109 as a mask, a silicon oxide film (passivation film 1o5, intermediate film 107a) on the wire bonding pad electrode 104 is etched by wet etching or dry etching.
, 107b, remove the protective film 1o8), and finally,
Photoresist pattern 109 is removed. (Figure 1-
e) In this example, the wire bonding electrode 1
Passivation film 1o6 on o4. Intermediate film 108 &
108b, the protective film 109 was removed, but if the film quality is the same as that of the passivation film, intermediate film, protective film, and interlayer insulating film 103, the eyebrow insulating film can also be removed at once.

Further, in this example, the inorganic thin film was formed by a photovapor phase chemical growth method, but it may be formed by a method that can be formed within the limit of the heat resistance temperature of the gelatin film.

Effects of the Invention As described above, the present invention can reduce the photolithography process for forming wire bonding holes, which was a problem in the conventional manufacturing method of color solid-state imaging devices, to one time, thereby increasing the manufacturing yield. The present invention has a significant effect on the method of manufacturing a color solid-state imaging device.

[Brief Description of the Drawings] Fig. 1 is a cross-sectional view showing a step-by-step method for manufacturing a color solid-state imaging device according to the present invention, and Fig. 2 is a cross-sectional view showing a step-by-step method for manufacturing a conventional color solid-state imaging device. It is a diagram. 100...Pa silicon substrate, 1o1...River...
PN junction photodiode, 104... Hat electrode for wire bond ink, 105... Passivation film, 106 R, 10eG, 106 B
, , Mountain - Colored film, 107a, 107b... Intermediate film, 108... Protection [, 109... Photoresist pattern. Name of agent Patent attorney Toshio Nakao and one other person (b
) /(II, -Rtsu, N-, @ /
4! Ltab scale - 1 color order, (C)! 07-”? IVI
IL Fig. 1 Fig. 2 (α)

Claims (1)

[Claims] The color mixture prevention film provided between each color pattern and the protective film of the color solid-state imaging device are formed of an inorganic thin film, and the wire bonding pad electrode is exposed by selectively etching the inorganic thin film on the wire bonding pad electrode part. A method of manufacturing a color solid-state imaging device, characterized in that: