JPH1123824A - Manufacture of color filter and developing solution to be used for its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove the residues of the developing solution after development processing and to avoid frilling of the color filter by incorporating a nonionic surfactant in the organic alkaline developing solution to be used for the color filter. SOLUTION: The organic alkaline developing solution containing the nonionic surfactant is used for the color filter. The substrate on which the color filter is to be formed is coated with a color photoresist, and the obtained photoresist coat film is patternwise exposed, and in the development process, subjected to development processing in at least >=2 times, and in the second developing process or later, to development with a developing solution having the nonionic surfactant added, thus permitting the residues of the developing solution to be effectively removed, and frilling of the color filter to be effectively avoided in a process for removing the developing solution residue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color filter applied to a solid-state image pickup device such as a charge-coupled device (CCD) and a liquid crystal display device (LCD) and a color filter used in the same. It relates to a developer for filters.

[0002]

2. Description of the Related Art For example, in a solid-state image pickup device using a CCD, a liquid crystal display device, etc., a color filter constituting these is subjected to pattern formation by exposure and development processing.

For example, an example of a CCD type color solid-state imaging device will be described with reference to FIG. In this example, the n-type semiconductor substrate 1 has p
A first well region 2 is formed, an n-type impurity introduction region 3 forming a photoelectric conversion element, for example, a photodiode is formed in a region where a light receiving portion is formed, and a p-type high-concentration positive charge is formed on the surface thereof. The light receiving section 5 in which the accumulation region 4 is formed is formed. A large number of the light receiving sections are formed on the semiconductor substrate 1 along the horizontal and vertical directions. Then, for example, a vertical shift register having a CCD configuration is formed adjacent to the light receiving units 5 arranged in a common vertical direction. In this vertical shift register, an n-type transfer region 8 is formed on a second p-type well region 7, and an Si-type transfer region 8 is formed thereon.
The transfer electrode 10 is formed via an insulating layer 9 such as O ₂ .
The transfer electrode 10 includes a plurality of sets of transfer electrodes that are vertically insulated from each other, and a clock voltage is applied between the sets of transfer electrodes. The generated charges are extracted and sequentially transferred in the vertical direction. A p-type high-concentration channel stop region 14 is formed in a portion of the semiconductor substrate 1 where charge transfer is to be avoided.

On the upper surface of the solid-state imaging device, a light-shielding film 11 made of an Al layer or the like having a light-receiving window 11w opened on the light-receiving portion 5 is formed almost entirely. Further, a light-transmissive planarizing film 12 is entirely formed on the light-shielding film 11, and the color filter 1 is formed on the planarizing film 12.
3 is formed.

The color filter 13 is, for example, shown in FIG.
As shown in the example of the arrangement pattern, for example, a light receiving unit 5 in which a red filter element R, a green filter element G, and a blue filter element B respectively correspond to a mosaic pattern.
It is arranged above.

The color filter 13 is formed of, for example, a pigment-dispersed photoresist. The color filter 13 can be formed by subjecting a pigment-dispersed photoresist to a known photoresist method, performing resist coating by spin coating of each color, and then performing exposure and development processing.

In the formation of the color filter 13, as shown in FIG. 3, due to poor development, a development residue 15 is generated in the vicinity of the pattern of the color filter element bodies R, G, and B and between these element bodies. In a solid-state imaging device and a liquid crystal display device using a color filter which can be obtained in a conventional manner, image defects are caused and the yield is reduced.

In order to remove the residue, a method of removing the residue by performing pure water washing in a process of manufacturing the color filter 13 has been adopted. Table 1 shows a developing process and a washing process of an example of a conventional color filter.

[0009]

[Table 1]

As shown in (Table 1), in step 1,
The substrate is rotated at a high speed and the developer is discharged for one second to spread the developer over the entire substrate. Here, the substrate is, for example, the above-described flattening film 1 for forming the color filter 13.
2 is a substrate such as a solid-state image sensor substrate or a glass substrate on which a glass substrate is formed. Examples of the developer include an inorganic developer such as a CD manufactured by Fuji Film Ohlin Co., and an organic developer such as a CD2 manufactured by Fuji Film Ohlin Co.
000 etc. can be applied.

Next, in step 2, while the developing solution is being discharged, the rotation speed of the substrate is reduced to 30 rpm and held for 3 seconds. Thereafter, in step 3, the discharging of the developing solution is stopped and left for 60 seconds. And develop.

After the development process, in step 4, the substrate is rotated at 50 rpm and rinsed with pure water for 40 seconds. This rinse is performed by spray cleaning in which nitrogen gas is mixed into pure water. Further, in step 5,
Cleaning is performed by pressurizing and spraying pure water at 00 rpm for 20 seconds to physically remove residues.

After passing through the step of removing the residue by the above-described method, in step 6, the substrate is rotated at a high speed of 3000 rpm for 15 seconds to perform a so-called spin dry step of shaking off pure water.

[0014]

However, as shown in the above-mentioned (Table 1), in the process of producing the color filter 13, after the development process, pure water is sprayed or the pressure is blown to remove the residue. If so, the adhesion between the color filter 13 and the flattening film 12 of the underlying film shown in FIG.
3 may peel off.

In particular, in the solid-state image pickup device, since the pattern size of the color filter 13 is finer than that in the case of the liquid crystal display device, the influence of the separation of the color filter 13 is more serious.

Therefore, in the present invention, a developer capable of effectively removing the residue of the developer after the development processing and effectively preventing the color filter from being peeled off in the residue removing step, and And a method for producing a color filter using the same.

[0017]

The color filter developer of the present invention is obtained by adding a nonionic surfactant to an organic alkaline developer.

The method of manufacturing a color filter according to the present invention includes a step of applying a color photoresist to a surface on which the color filter is formed, an exposure step of performing pattern exposure on a coating film of the color photoresist, and a developing step. In the developing process, at least two or more development processes are performed, and in the second and subsequent development processes,
The developing process is performed at least once using a developing solution obtained by adding a nonionic surfactant to an organic alkali developing solution.

According to the present invention, in the step of forming the color filter, after the development processing of the color photoresist,
The removal of the developer residue could be effectively performed.

Further, by forming a color filter using the developer for a color filter of the present invention,
The separation of the color filter in the step of removing the developer residue of the color filter could be effectively avoided.

[0021]

Embodiments of the present invention will be described below. The present invention relates to a solid-state image pickup device and a liquid crystal display device in which a pigment-based color filter is formed of a pigment-dispersed photoresist. The present invention relates to a liquid and a method for producing a color filter using the liquid.

Next, an example in which the present invention is applied to the above-described CCD type solid-state imaging device will be described. However, the present invention is not limited to this example, and can be applied to a liquid crystal display device. .

For example, an example of a CCD type color solid-state imaging device will be described with reference to FIG. In this example, the n-type semiconductor substrate 1 has p
A first well region 2 is formed, an n-type impurity introduction region 3 forming a photoelectric conversion element, for example, a photodiode is formed in a region where a light receiving portion is formed, and a p-type high-concentration positive charge is formed on the surface thereof. The light receiving section 5 in which the accumulation region 4 is formed is formed. A large number of the light receiving sections are formed on the semiconductor substrate 1 along the horizontal and vertical directions. Then, for example, a vertical shift register having a CCD configuration is formed adjacent to the light receiving units 5 arranged in a common vertical direction. In this vertical shift register, an n-type transfer region 8 is formed on a second p-type well region 7, and an Si-type transfer region 8 is formed thereon.
The transfer electrode 10 is formed via an insulating layer 9 such as O ₂ .
The transfer electrode 10 includes a plurality of sets of transfer electrodes that are vertically insulated from each other, and a clock voltage is applied between the sets of transfer electrodes. The generated charges are extracted and sequentially transferred in the vertical direction. A p-type high-concentration channel stop region 14 is formed in a portion of the semiconductor substrate 1 where charge transfer is to be avoided.

On the upper surface of the solid-state imaging device, a light-shielding film 11 composed of an Al layer or the like having a light-receiving window 11w opened on the light-receiving portion 5 is formed almost entirely. Further, a light-transmissive planarizing film 12 is entirely formed on the light-shielding film 11. The flattening film 12 is formed by depositing plasma SiN by a known low pressure CVD method, a thermosetting acrylic resin such as Optmer SS2211S (manufactured by Nippon Synthetic Rubber Co., Ltd.), or a polyimide resin such as PIQ-2200.
(Manufactured by Hitachi Chemical Co., Ltd.) can be applied.

After the transparent flattening film 12 is subjected to a surface treatment, a color filter is formed thereon by a color photoresist. The above-mentioned thermosetting acrylic resin,
For an organic film such as a polyimide resin, an ashing process is performed by a known dry asher before applying a color photoresist. That is, the surface is removed by ashing by about 10 to 30 nm. Thereby, the developability of the color filter can be improved.

The ashing conditions will be described below. Ashing equipment used: Single-wafer microwave ashing equipment Power: 500 W O ₂ (oxygen gas flow rate): 200 SCCM Stage temperature: 120 ° C. Pressure: 135 Pa Ashing time: 10 sec (acrylic resin) 20 sec (polyimide resin)

As shown in FIG. 2, the color filter 13 has, for example, a red filter element R, a green filter element G and a blue filter element B in a mosaic pattern. It is arranged on the light receiving section 5.

The color filter 13 is formed of, for example, a pigment-dispersed photoresist. For example, CG-6030L (manufactured by Fuji Film Ohlin Co., Ltd.) for G (green) and CR-62 for R (red) are used as pigment-dispersed photoresists constituting these color filters 13.
CB-6030L can be applied to 00L and B (blue), respectively.

The color filters 13 are formed by a photoresist method using a pigment-dispersed photoresist. The order of the photoresist for forming each color is not limited, but a color resist film is formed by spin coating using a known resist coater.

At this time, when plasma SiN, which is an inorganic film, is used as the flattening film 12 as a pretreatment for resist coating, HMDS (hexamethyldisilazane) is used.
The vapor treatment is performed for 60 seconds on a hot plate heated to 60 ° C. under normal pressure. On the other hand, when a thermosetting acrylic resin or a polyimide resin, which is an organic film, is used as the flattening film 12, this process can be omitted as necessary.

After coating and forming a color resist film on the flattening film 12 by a spin coater, a baking process using a known hot plate is performed, for example, at 90 ° C. for 60 seconds. The thickness of the color resist film after the baking process is, for example, about 1.5 μm.

Next, as an exposure process, for example, a known reduction type exposure apparatus (stepper) is used to set the exposure wavelength to i-line (365).
(nm).

As described above, after performing the resist coating by each color spin coating and the exposure processing, the development processing of the color resist is performed. In the present invention, a color filter developer in which a nonionic surfactant is added to an organic alkali-based developer is used in this development process.

The color filter developer includes:
For example, a volume ratio of 0.01 to 3 (%), preferably 0.5
(%) A nonionic surfactant is added to an aqueous solution of tetramethylammonium hydroxide at a concentration of about (%) with respect to the aqueous solution of tetramethylammonium hydroxide, for example, in a volume ratio of 0.01 to 5 (%), preferably 0 to 5%. .25 (%) can be used.

FIG. 4 is a schematic view of a developing apparatus for performing a developing process and a cleaning process for the color filter. This development processing apparatus has a processing chamber 90 in which development and cleaning are performed. An object to be processed 92, that is, a substrate 92 on which a color filter is formed, such as a semiconductor substrate 1 on which the image sensor described with reference to FIG. And a rotation base 91 which can be rotated. The processing chamber 90 is provided at its bottom with a discharge port for discharging each processing liquid described later, that is, a developing liquid, a cleaning liquid, and the like.

Further, first and second tanks 61 and 62 are provided, and these tanks 61 and 62 contain a first developer 61a and a second developer 62a, respectively. The first and second tanks 61 and 62 are supplied with nitrogen gas from a nitrogen gas supply unit 63 through filters 63 and 64, respectively.
The developing solutions 61a and 62a supplied at controlled flow rates by the nitrogen gas are supplied to the processing chamber 90
The first and second developer supply pipes 71 are provided to the first and second developer discharge nozzles 81 and 82 disposed above the
And 72 allow filters 73 and 74, respectively.
, The flow rate of which is controlled by the valves 75 and 76 so as to be supplied.

Further, first and second pure water discharge nozzles 101 and 102 are disposed above the processing chamber 90, and the first pure water discharge nozzle 101 has a pure water supply unit 10.
Pure water from 0 is passed through the filter 105 to the valve 10
6, while being supplied by the nitrogen gas from the nitrogen gas supply unit 63 via the filter 107, while being controlled by the valve 108.

The second pure water discharge nozzle 102 also has
Pure water from the pure water supply unit 100 is supplied through a filter 109 under the control of a valve 110.

Further, the object to be processed 92 is located below the processing chamber 90.
A third pure water discharge nozzle 103 for spraying pure water on the lower surface of the device is disposed, and pure water from the pure water supply unit 100 is supplied to the lower surface of the third nozzle by a valve 112 via a filter 111. Is done.

The process of developing and cleaning the color filter using the developing apparatus shown in FIG. 4 will be described below.

Table 2 shows a developing process and a washing process of an example of the color filter of the present invention.

[0042]

[Table 2]

As shown in (Table 2), in step 1,
For example, the first developer 61a is supplied to the first developer discharge nozzle 8
The liquid is discharged from the substrate 1 and sent onto the substrate to be processed 92. At this time, the substrate 92 to be processed is
The developer is rotated at a high speed of 00 rpm for 1 second to spread the developer over the entire object.

Next, in step 2, the first developer 61a
Is discharged, the rotation speed of the object to be processed 92 is set to, for example, 3
After dropping to 0 rpm and holding for 3 seconds, in step 3, the discharge of the developing solution is stopped, and development is performed by leaving for 30 seconds.

After this development processing, in step 4, a second development processing is performed. In this step 4, the second developing solution 62a shown in FIG. 4 is discharged from the second developing solution discharge nozzle 82 and sent onto the substrate 92 to be processed. At this time, the object to be processed 92 is, for example, 1
The developer is rotated at a high speed of 2,000 rpm for 2 seconds so that the developing solution can be spread over the entire object.

In the present invention, in the step 4 in which the second development process is performed, the developing solution according to the present invention, that is, the color obtained by adding a nonionic surfactant to an organic alkali developing solution is always used. Use a developer for the filter.

The developer for a color filter is, for example, 0.01 to 3 (%) in volume ratio, preferably 0.5 (%).
It is possible to apply a solution containing a nonionic surfactant in an aqueous solution of tetramethylammonium hydroxide having a concentration of, for example, 0.01 to 5 (%) in volume ratio to the aqueous solution of tetramethylammonium hydroxide. it can.

The nonionic surfactant contained in the color filter developer includes, for example, polyethylene 2
A grade alcohol ether, a polyoxyethylene alkylphenyl ether, a polyoxyethylene polyoxypropylene alkyl ether, a fatty acid alkanolamide, an alkylamine oxide, or the like can be used alone or as a mixture. Next, in step 5, the discharge of the developing solution is stopped, and the developing is performed by leaving for 30 seconds.

Next, in step 6, the substrate to be processed 92 is rotated by the rotating base 91 at, for example, 50 rpm, and
Rinse with pure water for 0 seconds. In this step 5, cleaning is performed by spraying pure water together with nitrogen gas from the first pure water discharge nozzle 101 shown in FIG. At the same time, the third pure water discharge nozzle 10
From 3, cleaning is performed by discharging pure water to the back surface of the target object 92.

Further, in step 7, the object to be processed 92 is rotated at, for example, 500 rpm by the rotation
Wash for 0 seconds. In this step 6, the supply of pure water from the first pure water discharge nozzle 101 is stopped, and pure water is pressurized from the second pure water discharge nozzle 102 instead of Cleaning is performed by discharging.

As described above, after cleaning is performed after the second development processing, the supply of pure water is stopped, and in the subsequent step 8, the substrate 92 to be processed is
A so-called spin dry is performed by rotating at a high speed of 000 rpm for 15 seconds to shake off pure water.

In the embodiment described above, the developing process is
Although the case where the processing is performed separately has been described, the present invention is not limited to this example, and can be applied to a case where the development processing is performed three or more times. In this case,
In the second and subsequent development processes, the development process is performed at least once using a developer obtained by adding a nonionic surfactant to the organic alkali-based developer according to the present invention. Also, depending on the developer concentration and the surfactant concentration described below,
Parameters such as time and number of revolutions in each step shown in (Table 2) are set to appropriate values.

As described above, when a color photoresist is applied to the surface on which the color filter is to be formed, pattern exposure is performed on the coating film of the color photoresist, and then development is performed, the development processing is performed at least twice. In the second and subsequent development processes, at least one development process using a developer in which a nonionic surfactant is added to an organic alkali-based developer is performed to produce a final color filter. FIG. 5 shows the state of the color filter obtained in FIG.

As shown in FIG. 5, the development residue 15 in the vicinity of the pattern of the color filter element bodies R, G, B and between these element bodies is a diagram of a state diagram when a color filter is formed by a conventional method. It can be seen that the number was significantly reduced as compared with No. 3.

Next, with respect to the color filter developer obtained by adding a nonionic surfactant to the organic alkali-based developer of the present invention, when an aqueous solution of tetramethyl hydroxide is applied to the organic alkali-based developer, The relationship between the concentration (volume ratio) (%) of the aqueous solution of tetramethylammonium hydroxide and the state of peeling of the test pattern of the color filter 13 will be described below.

FIG. 6 shows an arrangement diagram of the test pattern 30 of the color filter. The vertical and horizontal arrangement pitch of the test pattern 30 is, for example, 14 (mm) × 14 (mm). FIG. 7 shows an enlarged view 40 of the test pattern of the filter shown in FIG. 6, and FIG. 8 shows an enlarged view of the test pattern of the color filter shown in FIG. As shown in FIG. 8, the minimum test pattern of the color filter is, for example, 7 (μm) × 7 (μm).

Concentration (%) of aqueous solution of tetramethylammonium hydroxide as a developer for a color filter
And G (green), R (red), and B are the number of stripped color filter test patterns at each density.
It measured about each color filter of (blue). FIG. 9 shows the measurement results.

In this case, Optomer SS2211S (manufactured by Nippon Synthetic Rubber Co., Ltd.) is used as a flattening film serving as a base of the test pattern, and other various manufacturing conditions are the same as in the above-described embodiment.

Although the adhesion to the underlying flattening film varies depending on the color of the color photoresist used for the color filter, as shown in FIG. 9, the concentration of the aqueous solution of tetramethylammonium hydroxide (TMAH) is It can be seen that when the content is 0.01 to 3%, peeling of the color filter hardly occurs, and a color filter in a good state can be manufactured.

In the color filter developer of the present invention, the concentration (volume ratio) (%) of the nonionic surfactant contained in the organic alkali-based developer and the concentration near the color filter finally obtained were determined. The relationship with the state of the residue will be described below. In this case, NCW-601A (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the nonionic surfactant.

By changing the concentration (%) of the nonionic surfactant contained in the organic alkaline developer of the color filter developer, the density of the residue of 0.3 μm or more in the vicinity of the color filter at each concentration was reduced. The same color filter pattern as described above was measured. FIG. 10 shows the measurement results.

As shown in FIG. 10, when the concentration (%) of the nonionic surfactant contained in the organic alkaline developer is 0.01 (%) or more by volume, the residue near the color filter is It can be seen that the density can be significantly reduced. On the other hand, when the concentration (%) of the nonionic surfactant becomes high and exceeds 5%, it becomes difficult to completely remove the surfactant in the step of washing the developer. Therefore, the concentration of the nonionic surfactant is preferably set to 5% or less by volume.

In the embodiment described above, the developing step
In the case where the color filter of the liquid crystal display element is formed, the developing solution of the present invention is used, and the developing process is performed only once. Was effectively removed.

[0064]

According to the developer for a color filter constituting the solid-state imaging device and the liquid crystal display device of the present invention, in the process of forming the color filter, the residue of the developer is removed after the development of the color photoresist. Removal can now be performed effectively.

By forming a color filter using the developer for a color filter of the present invention,
The separation of the color filter in the step of removing the developer residue of the color filter could be effectively avoided.

Further, by reducing the residue of the developer of the color filter and avoiding the peeling of the color filter,
A solid-state imaging device using this color filter,
In addition, the yield of liquid crystal display elements and the like and the image quality can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a light receiving section of a solid-state imaging device.

FIG. 2 is a plan view illustrating an example of a configuration of a color filter.

FIG. 3 shows a state diagram of a color filter pattern and a residue when a color filter is produced by a conventional method.

FIG. 4 is a schematic view of an apparatus for performing a developing process and a cleaning process of a color filter.

FIG. 5 shows a pattern diagram of a color filter and a residue when a color filter is produced by the method of the present invention.

FIG. 6 shows a test pattern of a color filter.

FIG. 7 is an enlarged view of a test pattern of a color filter.

FIG. 8 is an enlarged view of a minimum test pattern of a color filter.

FIG. 9 shows the relationship between the concentration of trimethylammonium hydride and the number of peeled test patterns on a color filter.

FIG. 10 shows the relationship between the concentration of a surfactant in a developer and the residue density of a test pattern of a color filter.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 semiconductor base, 2 first well region, 3 impurity introduction region, 4 positive charge accumulation region, 5 light receiving section, 6 vertical shift register, 7 second well region, 8 transfer region,
Reference Signs List 9 insulating layer, 10 transfer electrode, 11 light shielding film, 12 flattening film, 13 color filter, 14 channel stop region, 30, 40, 50 color filter pattern, 61 first tank, 61 a first developer, 62
Second tank, 62a Second developer, 63, 64,
73, 74, 105, 107, 109, 111 filters, 65, 66, 75, 76, 106, 108, 11
0,112 valve, 71 first developer supply pipe, 72
Second developer supply pipe, 81 First developer discharge nozzle, 82 Second developer discharge nozzle, 90 Processing chamber, 9
Reference Signs List 1 rotating base, 92 substrate to be processed, 100 pure water supply unit, 101 first pure water discharge nozzle, 102 second pure water discharge nozzle, 103 third pure water discharge nozzle

Claims (3)

[Claims] 1. A color filter developer comprising a nonionic surfactant added to an organic alkali developer. 2. An aqueous solution of tetramethylammonium hydroxide having a concentration of 0.01 to 3% by volume as the organic alkali-based developer, wherein the concentration of the nonionic surfactant is tetramethylammonium hydroxide. The color filter developer according to claim 1, wherein the volume ratio of the developer to the aqueous solution of the oxide is 0.01 to 5%. 3. A step of applying a color photoresist on a surface on which a color filter is formed, an exposure step of performing pattern exposure on a coating film of the color photoresist, and a developing step, wherein the developing step includes: Perform development processing at least twice or more,
A method for producing a color filter, comprising, in the second and subsequent development processes, performing a development process using a developer in which a nonionic surfactant is added to at least one organic alkali-based developer.