JP3358280B2 - Developer for photosensitive polyimide precursor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a developer for a photosensitive polyimide precursor composition useful as an electronic material.

[0002]

2. Description of the Related Art Conventionally, as a developer for a photosensitive polyimide precursor, a dipolar aprotic solvent such as N-methylpyrrolidone or the like, to which a lower alcohol such as methanol or water has been added as a poor solvent (for example, see 58-66940
JP, JP-A-58-223149, JP-A-58-223149
No. 127738) was mainly used. However, such a developing solution is used when performing spray development or paddle development generally performed in a semiconductor manufacturing process.
Since the lower alcohol component of the developer evaporates, the development time becomes longer, and spray development or paddle development cannot be adopted.
There was a drawback that the immersion development method had to be used.
For this reason, an aromatic hydrocarbon such as xylene has been used as a poor solvent to be added to the developer (for example, JP-A-2-255989).

However, the xylene used in this developer is said to be toxic, such as causing dermatitis, irritation of the eyes, nose and throat, and causing bone marrow disorders due to benzene mixed as an impurity in xylene. (Organic solvent work chief textbook, Central Occupational Accident Prevention Association (198
9)) It was difficult to use for safety.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is an object of the present invention to develop a spray developing method and a paddle developing method without reducing the temperature of a developing solution or unevenness in the temperature of the developing solution. An object of the present invention is to provide a developer for a photosensitive polyimide precursor which can be satisfactorily and stably performed without causing unevenness and is easy to use from the viewpoint of safety and work.

[0005]

According to the present invention, there are provided (1) a dipolar aprotic polar solvent having a boiling point of 60 to 85% by weight ,
0 to 300 ° C., achieved by a photosensitive polyimide precursor-body developer flash point characterized by comprising the ester 5-30% by weight of more than 21 ° C. at one atmosphere pressure, water 5% by weight or more and less than 10 wt% Is done.

The dipolar aprotic polar solvent used in the developer of the present invention includes N-methylpyrrolidone, N,
N-dimethylacetamide, N, N-dimethylformamide, sulfolane, N, N-diethylformamide and the like can be mentioned, but other substances can of course be used.

The amount of the dipolar aprotic polar solvent is as follows:
It must be 60 to 85% by weight, more preferably 63 to 82% by weight, based on the total weight of the developer. 60
When the amount is less than 10% by weight, the developing speed becomes slow.
If the content is more than the weight percentage, care must be taken because problems such as the occurrence of a film in the photosensitive polyimide precursor film during development may occur.

[0008] As esters used in the present invention, benzyl acetic acid, 2-ethylhexyl acetate, isopentyl butyrate, butyl stearate, pentyl stearate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, benzoic acid isopentyl, benzyl benzoate, ethyl cinnamate, ethyl abietate, benzyl abietic acid, adipic acid bis (2-ethylhexyl), shea oxalic acid diethyl, dibutyl oxalate, oxalic acid dipentyl, diethyl malonate, dimethyl maleate ,
Diethyl maleate, dibutyl maleate, tributyl citrate, bis (2-ethylhexyl) sebacate, dimethyl phthalate, diethyl phthalate, monoacetin, diacetin, triacetin, monobutyrin, ethylene carbonate, propylene carbonate, ethyl lactate, ethyl pyruvate,
Propylene glycol monomethyl ether acetate,
Methyl-3-methoxypropionate, ethyl-3-ethoxypropionate, pentyl formate, butyl acetate, pentyl acetate, isopentyl acetate, 3-methoxybutyl acetate, sec-hexyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, propionic acid Butyl, isopentyl propionate, ethyl butyrate, butyl butyrate, isobutyl isobutyrate, ethyl 2-hydroxy-2-methylpropionate, diethyl carbonate and the like. Preferably, ethylene carbonate, propylene carbonate, ethyl lactate, ethyl pyruvate, propylene glycol monomethyl ether acetate, methyl-3-methoxypropionate,
Ethyl-3-ethoxy propionate and. These esters may be used alone or in combination of two or more.

The boiling point range of the ester is 100 ° C.
The temperature is preferably in the range of from 300 to 300 ° C, and more preferably in the range of from 120 ° C to 250 ° C. If the temperature is outside this range, the ability to control the temperature during the development of the developing solution becomes weak, so care must be taken. The flash point of the ester is preferably 21 ° C. or more at 1 atm. If the temperature is less than 21 ° C. at 1 atm, it must be handled in accordance with the Fire Service Law, Article 2, Class 4, Class 1 petroleum because of its high flammability at room temperature. May occur.

The compounding amount of the ester must be 5 to 30% by weight, more preferably 5 to 28% by weight, based on the total weight of the developing solution. If you fall outside this range,
Care must be taken because there is a risk that the developer will not be compatible or that the photosensitive polyimide precursor film will be easily cracked during development.

As described above, the developer according to the present invention contains 5% by weight or more and 10% by weight or more based on the total weight of the developer in a developer component comprising a specific amount of a dipolar aprotic solvent and a specific amount of an ester. Adding less than% of water is by weight. 5% by weight of water based on the total weight of developer
If the amount is less, the ability to suppress cracks decreases, which is not preferable. If the amount is more than 10% by weight, the developer components are not uniformly dissolved, so that they cannot be used.

The water to be added to the developer of the present invention is preferably pure water such as ion-exchanged water or distilled water in view of the requirements in the field of semiconductors in which the photosensitive polyimide precursor is used.

As the photosensitive polyimide precursor used in these developers, a varnish of a polyimide precursor generally prepared by combining a tetracarboxylic acid and a diamine in a dipolar aprotic solvent may be used. A mixture of an amino compound having a photosensitive group (for example, JP-B-59-52822), a compound capable of introducing a dimerizable or polymerizable group by light through an ester bond (for example, US Pat. No. 3,957,512); A mixture of a methylol acrylamide compound with a varnish of a polyimide precursor (for example, Proceedings of the Society of Polymer Science, p. 807, 1990)
Year), or a mixture of an acrylic monomer and a varnish of a polyimide precursor (for example, JP-A-2-50161).

Next, a method for developing a photosensitive polyimide precursor using the developing solution of the present invention will be described.

First, a varnish of a photosensitive polyimide precursor is applied on a substrate such as a silicon wafer by a method such as spin coating, and the solvent is scattered in a hot plate or an oven. To perform a predetermined amount of exposure. Thereafter, heat treatment such as dehydration baking is performed in a hot plate or oven. The developing method is such that a substrate such as a silicon wafer is fixed on
A spray method in which a developer is sprayed while rotating from 00 to 3000 rotations. A substrate such as a silicon wafer is fixed on a spinner, the developer is poured on the substrate, and the substrate is allowed to stand for development. Paddle development, immersion development in which the substrate is immersed in a developing solution tank, ultrasonic application immersion development in which ultrasonic waves are applied by immersion development, and the like can be mentioned, and development can be performed by any method. After development, it is washed with a rinse solution to remove the developer. Examples of the rinsing liquid include methyl alcohol, ethyl alcohol, and isopropyl alcohol. Then, heat treatment is performed at about 100 to 450 ° C. on a hot plate or an oven to convert the polyimide to polyimide, thereby obtaining a final product.

[0016]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Example 1 As a varnish of a photosensitive polyimide precursor, UR-3140 manufactured by Toray Industries, Inc. was spin-coated at 1500 rpm for 30 seconds on a 4-inch silicon wafer.
Then, after drying in an oven at 80 ° C. for 30 minutes, a contact aligner PLA-5 manufactured by Canon Inc.
01F, through a chrome photomask, 36
Exposure at 200 mJ / cm ² was performed at a wavelength of 5 nm.

Using a developer consisting of 65% by weight of N-methylpyrrolidone, 27% by weight of propylene carbonate (boiling point: 238 ° C., flash point at 1 atm 132 ° C.), and 8% by weight of water, Tokyo Electron was used. Paddle development was performed using a clean truck manufactured by KK

As a developing condition, a developing solution was applied to a silicon wafer at 100 rotations for 3 seconds, then left standing for 5 minutes to perform development, and isopropyl alcohol was sprayed at 500 rotations for rinsing.

During development, the temperature of the wafer is 2 at the center.
2.2 ° C., 22.0 ° C. in the periphery (in a 23 ° C. clean room).

Observation of the development results with an optical microscope shows that
The through hole of 0 μm was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer. Further, there was no odor and the workability was good.

EXAMPLE 2 75% by weight of N-methylpyrrolidone and 16 parts of propylene carbonate
The pattern processing was performed under exactly the same conditions as in Example 1 except that a developing solution consisting of 9% by weight of water and 9% by weight of water was used.

During development, the temperature of the wafer is 2 at the center.
The temperature was 1.9 ° C. and the surrounding area was 21.8 ° C. (in a clean room at 23 ° C.).

When the result of the development was observed with an optical microscope,
The through hole of 0 μm was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer. Further, there was no odor and the workability was good.

Example 3 Example 3 was repeated except that a developer consisting of 65% by weight of N-methylpyrrolidone, 27% by weight of ethylene carbonate (boiling point: 242 ° C., flash point at 1 atm: 160 ° C.) and 8% by weight of water was used. Pattern processing was performed under exactly the same conditions as in Example 1.

During development, the temperature of the wafer is 2 at the center.
The temperature was 2.1 ° C and the surrounding area was 21.8 ° C (in a clean room at 23 ° C).

Observation of the development results with an optical microscope shows that
The through hole of 0 μm was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer. Further, there was no odor and the workability was good.

Example 4 A developer containing 82% by weight of N-methylpyrrolidone, 10% by weight of propylene glycol monomethyl ether acetate (boiling point: 146 ° C., flash point at 1 atm: 46 ° C.) and 8% by weight of water was used. The pattern processing was performed under exactly the same conditions as in Example 1.

The temperature of the wafer during development is 2
The temperature was 2.1 ° C and the surrounding area was 21.8 ° C (in a clean room at 23 ° C).

When the result of the development was observed with an optical microscope,
The through hole of 0 μm was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer. Further, there was no odor and the workability was good.

Example 5 65% by weight of N-methylpyrrolidone and ethyl-3-ethoxypropionate (boiling point 165 ° C., flash point at 1 atm.
(8 ° C.) Pattern processing was carried out under exactly the same conditions as in Example 1 except that a developer consisting of 27% by weight and 8% by weight of water was used.

The temperature of the wafer during development is 2
The temperature was 2.1 ° C and the surrounding area was 21.8 ° C (in a clean room at 23 ° C).

Although the development time required a little longer, when the development result was observed with an optical microscope, the 20 μm through hole was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer. Was. Further, there was no odor and the workability was good.

Comparative Example 1 90% by weight of N-methylpyrrolidone and ethyl acetate (boiling point 7
7 ° C, flash point at 1 atm-4 ° C) 7% by weight and 3% by weight of water
Pattern processing was performed under exactly the same conditions as in Example 1 except that a developing solution consisting of

During development, the temperature of the wafer is 1 at the center.
The temperature was 9.1 ° C. and the temperature at the periphery was 16.8 ° C. (in a clean room at 23 ° C.).

Observation of the development results with an optical microscope revealed that a 20 μm through-hole was resolved at the center of the wafer, but a 100 μm through-hole was not resolved at the periphery, resulting in uneven development. Was.

Comparative Example 2 65% by weight of N-methylpyrrolidone and 27% by weight of xylene
Example 1 except that a developer consisting of water and 8% by weight of water was used.
The pattern processing was performed under exactly the same conditions as described above.

The temperature of the wafer during development is 2
The temperature was 2.0 ° C. and the peripheral portion was 21.9 ° C. (in a clean room at 23 ° C.).

When the result of the development was observed with an optical microscope,
The 0 μm through-hole was completely resolved, and uniform resolution was obtained from the center to the periphery of the wafer, but the xylene odor was intense and irritated the eyes, nose and throat.

Comparative Example 3 Pattern processing was carried out under the same conditions as in Example 1 except that a developer consisting of 90% by weight of N-methylpyrrolidone, 5% by weight of propylene carbonate and 5% by weight of water was used. During the development, the temperature of the wafer was 22.3 ° C. at the center and 2% at the periphery.
2.2 ° C. (in a 23 ° C. clean room).

Observation of the result of the development with an optical microscope revealed that the photosensitive polyimide precursor film was roughened and reduced, and a good pattern could not be obtained.

[0042]

By using the developing solution of the present invention,
Since there is no temperature drop or temperature unevenness of the developer, there is an advantage that spray development or paddle development can be performed satisfactorily and stably without causing unevenness in development. In addition, it has remarkable practical effects such as easy use in terms of safety, storability and workability.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-133062 (JP, A) JP-A-58-127924 (JP, A) JP-A-58-223149 (JP, A) JP-A-6-127149 282081 (JP, A) JP-A-7-20639 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/32 G03F 7/027 514 H01L 21/027

Claims (1)

(57) [Claims] 1. A dipolar aprotic polar solvent of 60 to 85% by weight, a boiling point of 100 to 300 ° C. and a flash point of 1 atm.
A developer for a photosensitive polyimide precursor , comprising 5 to 30% by weight of an ester at 1 ° C or more and 5% to less than 10% by weight of water.