JP2000122306A - Production of color filter for solid image pickup element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to drastically shorten the time for development and to improve the workability of development work by carrying out the development work while maintaining a developer in a specific temperature range. SOLUTION: The development processing is executed while the developer is maintained at a liquid temperature exceeding 30 deg.C and below 35 deg.C at the time of the development in the process for producing a color filter for a solid image pickup element by subjecting a colored lens (color resist) film of a pigment dispersion type having photosensitivity to exposure and development. As a result, the developability of the color resist film can be improved and the development speed can be increased while existing devices are used. Piping which is composed of a double piping structure by inserting inner piping 2 into outer piping 1 in which a warmed temperature medium, such as pure water, blows and passes the developer into the inner piping 2 is used at the method for regulating the liquid temperature to be exceeding 30 deg.C and below 35 deg.C. The inner piping 2 of the outer piping 1 and the inner piping 2, which comes at least directly into contact with the developer, is formed of a material having chemical resistance to the developer, for example, a fluororesin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter for a solid-state image sensor, and for example, relates to a CCD (Charge).
-Coupled Device) relates to a method of manufacturing a color filter for an image sensor.

[0002]

2. Description of the Related Art In recent years, in the manufacture of a CCD image pickup device for color display, a pigment-dispersed colored resist having photosensitivity (hereinafter referred to as a color resist) is used for a material of an on-chip color filter formed on a light receiving sensor portion. ) Is being used. As a method for manufacturing an on-chip color filter using such a color resist, a method using a lithography process having processing steps such as exposure, development, and baking (post-baking) is employed.

[0003] In the developing step of this lithography process, processing has conventionally been carried out at a standard solution temperature of a developing solution of 26 ° C. Usually, development using both a paddle development system and a spray development system is performed.

[0004]

However, pigment-dispersed color resists having photosensitivity generally have poor developability, such as being hardly developed, and tend to have a long development time. It is considered that this is because a large amount of pigment contained in the color resist functions as a dissolution inhibitor in the developer, and the solubility of the color resist is reduced. As a result, the workability of the development process is deteriorated, and the machine tact of an apparatus (spinner) that automatically performs a series of processes such as coating, exposure, development, and baking of a color resist is increased. .

[0005]

In order to solve the above-mentioned problems, the present invention provides a color dispersion for a solid-state imaging device by exposing and developing a photosensitive pigment-dispersed colored resist (color resist) film. In a method for producing a filter, a developing solution is allowed to exceed 30 ° C.
The developing process is performed while maintaining the solution temperature at 5 ° C. or lower.

In the present invention, since the developing process is performed with the temperature of the developing solution higher than the conventional standard solution temperature, the solubility of the color resist film in the developing solution is increased. In addition, since the temperature of the developing solution is not less than 30 ° C. and not more than 35 ° C. which does not adversely affect the existing apparatus and effectively enhances the solubility, the color resist film is formed using the existing apparatus. The developability can be effectively improved, and the development speed can be sufficiently increased.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for manufacturing a color filter for a solid-state imaging device according to an embodiment of the present invention will be described. Here, an example in which the present invention is applied to, for example, the manufacture of a color filter for a CCD imaging device will be described.

In the present embodiment, prior to manufacturing a color filter for a CCD image sensor, a semiconductor substrate is prepared which has been subjected to the manufacturing process of the CCD image sensor to a state before manufacturing the color filter. In other words, the semiconductor substrate has, for example, a light-receiving sensor unit that performs photoelectric conversion formed on the surface layer thereof, a plurality of vertical transfer electrodes formed on the upper surface of the semiconductor substrate via an oxide film, and a light-shielding film that covers the transfer electrodes vertically. And an interlayer film is formed so as to cover the light shielding film.

A pigment-dispersed colored resist (color resist) having photosensitivity is first applied to such a semiconductor substrate in the same manner as in a lithography process in a usual color filter manufacturing process. A resist film is formed. Here, a negative resist film is used as the color resist film.

Next, the color resist film is exposed, developed and post-baked to form a first color filter at a desired position on the semiconductor substrate. In this developing step, for example, an alkali developing solution is used as the developing solution, the developing solution is heated to a temperature of more than 30 ° C. and 35 ° C. or less, and development is performed while maintaining this temperature.

When the temperature of the developing solution is set to a temperature exceeding 30 ° C. and a temperature not exceeding 35 ° C., it is within this range that the developability of the color resist film can be effectively improved by using an existing apparatus. This is because the development speed can be sufficiently increased. That is, even if the temperature of the developing solution is 26 ° C. or more, which is the conventional standard solution temperature, if the temperature is 30 ° C. or less, the effect of promoting the developability is small, and the developing speed cannot be sufficiently increased. When the liquid temperature exceeds 35 ° C., no significant change is observed in the effect of increasing the developing speed, and the components such as the filters of the existing apparatus assume that the liquid temperature is about 26 ° C. This is because if the liquid temperature exceeds 35 ° C., there is a possibility that the above-mentioned components may be defective.

In the present embodiment, as a method of adjusting the liquid temperature to be higher than 30 ° C. and lower than 35 ° C., for example, a method of passing a developing solution through a pipe having an outer surface in contact with a warm medium is adopted. Then, the temperature-adjusted developer is supplied to the color resist film through a pipe. Specifically, as shown in the plan view of FIG. 1A and the cross-sectional view taken along the line XX in FIG. 1A, (b), an outer pipe through which a warm medium such as warm pure water flows. 1
The inner pipe 2 is inserted through the inner pipe 2 to form a double pipe structure, and the inner pipe 3 is a pipe through which the above-described developer passes. At least, of the outer pipe 1 and the inner pipe 2, at least the inner pipe 2 in direct contact with the developer is made of a material having chemical resistance to the developer, for example, a fluorine-based resin. .

By adopting the method of indirectly warming the developing solution as described above, it is possible to prevent the risk of directly warming the developing solution and to prevent a change in the concentration of the developing solution while keeping the temperature of the developing solution at a desired level. Temperature can be adjusted. There is also an advantage that it is not necessary to newly secure a space for installing a new device for warming the developer.

Various types of developing methods, such as a paddle developing method, a spray developing method, and a method in which paddle developing and spray developing are used in combination, can be used as the developing method. Examples of the alkali developer used include:
For example, a sodium hydrogen carbonate solution can be mentioned, but the type of the alkali developing solution is not particularly limited.

Further, in the present embodiment, for example, a spinner generally used conventionally is used in the above-described coating, developing and post-baking steps of the color resist, and a reduction step generally used in the exposure step is used. A projection exposure apparatus is used. However, it goes without saying that other devices can be used.

Then, the above-described series of steps of coating, forming, exposing, developing, and post-baking the color resist film are repeated for the number of colors of the desired color filter provided in the CCD image pickup device. For example, when forming color filters of three colors, it may be repeated three times. As a result, a color filter for a CCD imaging device having a desired number of colors is manufactured.

In the present embodiment, the developing process is performed at a temperature higher than the conventional standard solution temperature, that is, higher than 30 ° C. and lower than 35 ° C., so that the developing process is performed without adversely affecting the existing apparatus. The solubility of the color resist film in the liquid can be effectively increased. Therefore, the developability of the color resist film can be effectively improved using the existing apparatus, and the developing speed can be sufficiently increased.

FIGS. 2 and 3 show Blue, Red, and Gr.
When a color filter is manufactured using the color resists of the three primary colors, e.g.
This shows the transition of the development time at each developer temperature of each color when the development is performed at 35 ° C. and 35 ° C. FIG. 4
Are Blue, Re when the developer temperature is changed from 23 ° C. to 26 ° C. and when the developer temperature is changed from 26 ° C. to 35 ° C.
It shows the reduction time (time reduction) and the time reduction rate (time reduction rate) of the development time for each color of d and Green.

As apparent from FIGS. 2 and 3, the development time of each color is B at 26 ° C., which is the conventional standard solution temperature.
lue: 180 sec, Red: 305 sec, Gre
en: 160 sec. Normally, when developing a resist film in which a pigment is not dispersed by lithography, the development time is generally within 120 sec. Therefore, it is confirmed that the pigment suppresses dissolution of the resist in the developer.

On the other hand, when the development is carried out at a developer temperature of 35 ° C., the development time of each color is set to Blue: 120
sec, Red: 235 sec, Green: 120 s
ec, and it can be seen that the development time is extremely shortened. In particular, from FIG.
When the temperature is changed from 26 ° C. to 35 ° C., the time reduction ratio of the development time is higher than when the temperature is set to 25 ° C., and the developability can be improved effectively.
It is found that the developing speed can be sufficiently increased. In addition,
At each temperature, the characteristics after development, that is, pattern peeling,
There was no development residue or development residue, and the level of the characteristics after development was equivalent.

Thus, as is apparent from the above results, according to the present embodiment, the development speed of the color resist film can be sufficiently increased, and the development time can be greatly reduced. Workability can be improved, and machine tact can be shortened when a series of processes such as application, exposure, development, and baking of a color resist are performed by a spinner.

[0022]

As described above, according to the method of manufacturing a color filter for a solid-state imaging device according to the present invention, the temperature of the developer is set to be higher than 30.degree. Since the developing process is performed with the solubility increased, the developing speed of the color resist film can be sufficiently increased while using the existing apparatus. Therefore, the development time can be greatly reduced, the workability of the development processing can be improved, and the machine tact when a series of processing such as application, exposure, development, and baking of a color resist is performed by a spinner is reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a developer pipe used in a method of manufacturing a color filter for a solid-state imaging device according to the present invention, wherein (a) is a plan view and (b) is XX in (a). It is arrow sectional drawing.

FIG. 2 is a graph showing a relationship between a developing time and a developing solution temperature when color resists of three primary colors are used.

FIG. 3 is a table showing a relationship between a developing time and a developer temperature (23 ° C., 26 ° C., 35 ° C.) when color resists of three primary colors are used.

FIG. 4 shows that when the developer temperature is changed from 23 ° C. to 26 ° C.,
FIG. 6 is a diagram showing a reduction time (time reduction) and a time reduction rate (time reduction rate) of the development time for each of the three primary colors when the temperature is changed from 35 ° C. to 35 ° C.

[Explanation of symbols]

 1 ... Outer piping, 2 ... Inner piping

Claims (3)

[Claims] 1. A method for producing a color filter for a solid-state imaging device by exposing and developing a photosensitive pigment-dispersed colored resist film, wherein the developing solution is maintained at 30 ° C. A method for producing a color filter for a solid-state imaging device, wherein the development process is performed while maintaining the solution temperature at a temperature exceeding 35 ° C. or lower. 2. In the development, the temperature of the developing solution is adjusted to a temperature exceeding 30 ° C. and 35 ° C. or less by passing the developing solution through a pipe in which a heating medium is brought into contact with the outer surface. The method for producing a color filter for a solid-state imaging device according to claim 1, wherein the color resist film is supplied to the colored resist film via a pipe. 3. The method according to claim 2, wherein the pipe is an inner pipe inserted into an outer pipe through which the warm medium flows.