JPH04133062A - Developer for photosensitive polyimide - Google Patents

Abstract

PURPOSE:To prevent the degradation in developability by adding water further into a developer component consisting of a specific ratio of a bipolar non- protonic polar solvent and a specific ratio of arom. hydrocarbon at a prescribed ratio of the weight of the developer. CONSTITUTION:The compounding rate of the bipolar non-protonic polar solvent is specified to 60 to 80wt.% of the total weight of the developer and 10 to 30wt.% arom. hydrocarbon which is an org. solvent having 100 to 200 deg.C b. p. and >=5wt.% and <10wt.% water re mixed. The fall of the temp. of the developer and the unequal temp. of the soln. are obviated in this way and, therefore, the stable execution of spray development and paddle development without unequal development is possible. In addition, the cracking of the polyimide film is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a developer for a photosensitive polyimide composition useful as an electronic material.

[Prior Art] Conventionally, as a developer for a photosensitive polyimide composition, a dipolar aprotic polar solvent such as N-methylpyrrolidone is used.
~80 parts by weight and 20 to 50 parts by weight of a lower alcohol such as methanol as a poor solvent were mainly used. However, when using this type of developer, spray development or puddle development, which is commonly used in semiconductor manufacturing processes, lower alcohol components in the developer evaporate, causing the temperature of the developer to drop during development. However, there were drawbacks such as a longer development time.

For this reason, adding aromatic hydrocarbons such as xylene as a poor solvent to the developer is being considered;
If such a substance is added, the temperature of the developer during spray development or paddle development will not decrease much, but after the polyimide film is formed, it will take a long time before development, for example, if the production line is stopped for 1 to 2 days. However, when developing the film, cracks often occur in the film.

On the other hand, in order to prevent such racking, it has been proposed to use a developer consisting of an aprotic polar solvent and water in an amount of 10% to 50% by weight (Japanese Patent Laid-Open No. 58
-66940).

However, in the case of the developer according to the present invention, spray development and puddle development cannot be used because it is relatively easy to cause a temperature drop in the developer and liquid temperature unevenness, which causes uneven development.
There is a drawback that the method has no choice but to use the immersion development method.

[Problems to be Solved by the Invention] The present invention was devised in view of the various drawbacks of the prior art, and its purpose is to eliminate the temperature drop and unevenness of the developer solution, and to improve spray development and paddle development. It is an object of the present invention to provide a developer for photosensitive polyimide which can perform the process well and stably without causing uneven development, and which does not cause cracks even when the polyimide film is left for a long time after formation before development. .

[Means to solve the problem] The object of the present invention is achieved by the following configuration.

1. A developer for photosensitive polyimide, comprising 60 to 80% by weight of a dipolar aprotic polar solvent, 10 to 30% by weight of aromatic hydrocarbon, and 5% to less than 10% by weight of water.

2. The developer for photosensitive polyimide as described in the preceding item, which is an aromatic hydrocarbon or an organic solvent with a boiling point of 100 to 200°C.

3. The developer for photosensitive polyimide according to item 1 above, wherein the aromatic hydrocarbon is xylene.

The dipolar aprotic polar solvents used in the present invention include N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, γ-butyrolactone, sulfolane, N.

Examples include N-diethylformamide, but other materials can of course also be used.

The amount of the dipolar aprotic polar solvent to be blended must be 60 to 80% by weight, more preferably 63 to 76% by weight, based on the total weight of the developer.

If it is out of this range, the compositions of the developer will not be compatible with each other, leading to problems such as not being able to obtain a transparent developer or deterioration of developability, so care must be taken.

The aromatic hydrocarbon used in the present invention is preferably one that evaporates at an appropriate rate during development of the photosensitive polyimide and has the effect of suppressing temperature changes during development, such as benzene, toluene, xylene, Examples include those that consist of a single component such as ethylbenzene, and those that have a boiling point within a certain temperature range such as solvent naphtha. The preferred boiling point range of aromatic hydrocarbons is 10
It is preferably in the range of 0 to 200°C, more preferably in the range of 130 to 170°C. If the temperature is outside this range, the ability of the developer to control the temperature during development will be weakened, so care must be taken. These components may be used alone or in combination of two or more.

A particularly preferred aromatic hydrocarbon in the present invention is xylene.

The blending amount of aromatic hydrocarbon is 10% based on the total weight of the developer.
It needs to be in the range of ~30% by weight, more preferably 13-28% by weight.

If it deviates from this range, care must be taken because there is a risk that the developing solution will not be compatible or that cracks will easily form when developing the photosensitive polyimide.

As described above, the developer according to the present invention further includes a developer component consisting of a specific amount of a dipolar aprotic polar solvent and a specific amount of aromatic hydrocarbon, and further contains 5% by weight or more and 10% by weight based on the total weight of the developer. It is important to add less than % by weight of water. If the amount of water added is less than 5% by weight based on the total weight of the developer, the ability to suppress cracks will decrease, which is undesirable, and if it is more than 10% by weight, the components of the developer will not dissolve uniformly. , cannot be used.

Note that the water 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 of the semiconductor field where photosensitive polyimides are used.

The photosensitive polyimide used in the present invention includes:
A polyimide precursor varnish that is generally produced by combining a tetracarboxylic acid and a diamine in a dipolar aprotic polar solvent is mixed with an amino compound having a photosensitive group such as a methacrylic group (for example, 59-52
No. 822), those in which a light-dimerizable or polymerizable group is introduced through an ester bond (for example, US Pat. No. 395)
7512 specification), a mixture of an N-methylol acrylamide compound with a varnish of a polyimide precursor (for example, Proceedings of the Society of Polymer Science, p. 807, 1990), or a mixture of an acrylic monomer with a varnish of a polyimide precursor ( For example, Japanese Patent Application Laid-open No. 2-50161).

Next, a method for developing photosensitive polyimide using the developer of the present invention will be explained.

First, a photosensitive polyimide varnish is applied onto a silicon wafer using a method such as a spin cord, and a solvent is scattered on a hot plate or in an oven. after that,
After a predetermined amount of exposure has been performed, the wafer is fixed on a spinner, and a developer is sprayed onto the spinner at 100 to 3,000,000 revolutions per minute (spray development). Alternatively, a developer is placed on the wafer on a spinner and the wafer is left standing to develop (paddle development). Other developing methods include immersion development in which the wafer is immersed in a developer tank, and irradiation with ultrasonic waves during immersion development, but any method can be used for development. However, in view of the characteristics of the developer of the present invention, it is preferable to perform spray development or puddle development.

Thereafter, rinsing is performed using alcohols, acetic esters, etc. to obtain a predetermined pattern.

The finished product is heat-treated at about 100-450'C in an oven or hot plate to convert it into polyimide, resulting in the final product.

[Examples] The present invention will be specifically described below based on Examples, but the present invention is not limited thereto.

Example 1 UR-3 manufactured by Toshiku Co., Ltd. as a photosensitive polyimide varnish
140 on a 4-inch silicon wafer.
Spin coating was performed for 500,500 rotations for seconds. After that 80
After drying for 1 hour at
Exposure was performed at a wavelength of 200 mJ.

This sample was subjected to puddle development using a clean track manufactured by Tokyo Electron Ltd. using a developer consisting of 65% by weight of N-methylpyrrolidone, 2% by weight of xylene and 8% by weight of water.

The developing conditions were as follows: a developer was applied to the silicon wafer for 3 seconds at 100 revolutions, then the silicon wafer was left standing for 5 minutes for development, and isopropanol was sprayed at 500 revolutions for rinsing.

During development, the temperature at the center of the wafer was 22.0°C and the temperature at the periphery was 21.9°C in a 23°C clean room.

When the development results were observed with an optical microscope, it was found that the resolution was uniform from the center to the periphery.

Comparative Example 1 A polyimide film was formed, exposed, developed, and rinsed in the same manner as in Example 1, except that a developer containing 70% by weight of N-methylpyrrolidone and 30% by weight of methanol was used.

During development, the temperature at the center of the wafer was 19.6°C and the temperature at the periphery was 17.3°C in a 23°C clean room.

When the development results were observed using an optical microscope, it was found that the central part had good resolution, but the peripheral part had insufficient resolution.

Example 2 A polyimide film was prepared in the same manner as in Example 1, except that the exposed sample was left for 24 hours and then heat treated at 80°C for 15 minutes. Formation, exposure, development and rinsing were performed.

During development, the temperature at the center of the wafer was 22.0°C and the temperature at the periphery was 21.9°C in a 23°C clean room.

When the development results were observed with an optical microscope, it was found that the resolution was uniform from the center to the periphery.

Comparative Example 2 A polyimide film was formed, exposed, developed, and rinsed in the same manner as in Example 2, except that a developer containing 70% by weight of N-methylpyrrolidone and 30% by weight of methanol was used.

During development, the temperature at the center of Ueno 1- was 22.0°C and the temperature at the periphery was 21.9°C in a 23°C clean room.

When the development results were observed under an optical microscope, cracks were found around the through holes.

Example 3 A polyimide film was formed in the same manner as in Example 2, except that a developer containing 76% by weight of N-methylpyrrolidone, 15% by weight of xylene, and 9% by weight of water was used.
Exposure, development and rinsing were performed.

During development, the temperature at the center of the wafer is 21.8°C and the temperature at the periphery is 21.7°C in a 23°C clean room.
Met.

When the development results were observed with an optical microscope, it was found that the resolution was uniform from the center to the periphery.

Comparative Example 3 When a developer was prepared by blending 70 parts by weight of N-methylpyrrolidone with 30 parts by weight of xylene and 15 parts by weight of water, the solution became cloudy and could not be used.

[Effects of the Invention] Since the developer of the present invention is configured as described above, there is no temperature drop or temperature unevenness of the developer, so spray development or puddle development can be carried out well and stably without uneven development. There is an advantage that it can be done.

In addition, even if the polyimide film is left for a long time after being formed and before being developed, no cracks will occur, which provides remarkable practical effects.

Claims (1)

[Scope of Claims] 1. A photosensitive polyimide comprising 60 to 80% by weight of a dipolar aprotic polar solvent, 10 to 30% by weight of an aromatic hydrocarbon, and 5% to less than 10% by weight of water. developer solution. 2 Aromatic hydrocarbons have a boiling point of 100-200℃
The developer for photosensitive polyimide according to claim 1, which is an organic solvent. 3. The developer for photosensitive polyimide according to claim 1, wherein the aromatic hydrocarbon is xylene.