JPS5866940A - Developer for heat resistant photosensitive resin - Google Patents

Abstract

PURPOSE:To obtain an insulating film pattern free from cracks of >=2mum size by patterning a photosensitive polyimide resin precursor with a developer consisting of an aprotic polar solvent and water or further contg. an org. solvent. CONSTITUTION:A preferred example of an aprotic polar solvent is N,N-dimethylformamide, N,N-dimethylacetoamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone or N-acetyl-epsilon-caprolactam, and ion exchanged water is desirably used as water from the requirement of the semiconductor industry. The preferred amount of water blended with the solvent is 10-50wt% basing on the total weight of the resulting developer. A conventional org. solvent may be added as a tertiary component. Development is carried out by an immersion method or a spraying method, and development by immersion is finished in 1-5min at room temp. The developed picture is rinsed to remove the developing solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel developer for patterning photosensitive BO1 imide thread resin precursors.

In recent years, in the field of the semiconductor industry, Boiiimide yarn M resin has been used in some areas as an interlayer insulating film for multilayer wiring. Furthermore, recently, a pattern forming ability such as that of a photoresist has been imparted to BoIimide resin precursors.

Attempts have been made to use a photosensitive bo-11 imide precursor to streamline the process. For example, the process of forming an interlayer film using a photosensitive polyimide resin precursor is shown below.

(1) Coating: Coating a photosensitive polyimide precursor face onto a predetermined substrate.

(2) Privilege: Dry the solvent and bond with the photosensitive polyimide resin coating.

(3) Exposure: Exposure ↑ through a photomask with constant Pk◎
At this time, the exposed areas 11 are crosslinked and become insoluble in the equalizing solution, giving a negative image.

(4) Development: Unexposed areas are dissolved and removed with a developer, and then washed with a rinse solution to obtain a pattern of the polyimide precursor.

(5) Post-bake: Heat treatment to remove developer and rinse fI! L'x is evaporated and the polyimide precursor is further converted to boimide.

Changes in the film Ji2 during the above series of steps
Then, the thickness of the coating film after prebaking decreases to approximately 80% to 4'kIJ after the two steps of development and postbaking, although the method of imparting photosensitization varies. Therefore, a coating of about 1.3 to 2.5 times as much as the final cured film of the staghorn rhinoceros will provide peace of mind. In semiconductor integrated circuits, wiring #14
Since Al is usually used for the body with a thickness of about 2 μm, K is required to have a final film thickness of at least 2 μm or more in order to insulate it.

However, conventional developers include, for example, dimethylacetamide alone or a mixture of dimethylacetamide and dioxane (tJL ratio 1:1).

In addition, in a developing solution consisting of a good solvent and a poor solvent for the precursor of bo-11imide, such as a 1:1 mixture of dimethylacetamide and methanol, if the film thickness after prebaking exceeds 3 μm, the film will crack during development. .

Even a final cured film with a thickness of 1.5 μm could not be obtained.

The purpose of the present invention is to eliminate the drawbacks of the prior art described above, and to
The object of the present invention is to provide a developer for obtaining a crack-free Fek film as described above.

This is the result of considering developing solvents for glazes for this purpose.

Contrary to his expectations, he discovered that water was an essential ingredient.

In other words, it was found that a mixed solvent obtained by adding water to an aprotic polar solvent can develop a coating film of a polyimide precursor having a thickness of 3 μm or more without causing cracks.

The aprotic polar solvent used in the present invention includes N.

N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoquinde, N-methyl-2-pyro1
1 ton, 1,3-dimethyl-2-imidazolidinone, N
Preferred examples include -acetyl-ε-caprolactam, but the present invention is not limited to this as long as the polyimide precursor in the unrodded base portion is soluble. Further, these 41 compounds may be used alone or in combination of two or more.

As the water used in the present invention, it is desirable to use ion-exchanged water in view of the requirements of the semiconductor industry. Is the amount of water mixed 1 to the total volume of developer? ]+l'+: Selected from the range of % by volume or more and 50% or less (when no M solvent is blended,
The aprotic polar solvent will be the remainder, 90% by weight or less, 5
0Φ″ amount% Kakigami is blended).

If 10% less work is done on the lid, a crack will appear on the second lid, and the 50
If the amount exceeds the percentage of heavy lids, the base portion will not be dissolved yet and development will not be possible.

The present invention is applicable even if a conventional organic solvent is added as the third component. The third component is methyl alcohol, isopropyl flucol, toluene, xylene, ryosetone, and methyl ethyl ketone.

Examples include methyl cellosolve and ethyl cellosolve. Further, these compounds may be used alone or in combination of two or more kinds. The amount added is a large amount of aprotic polar solvent.

Development is done by dipping, spraying, and immersion methods.

The immersion method takes 1 to 5 minutes to complete at room temperature. The developed image is washed with an 11-ounce solution that removes the developing solvent. The rinsing liquid uses a poor solvent of poly-11-amic acid (polyimide precursor) which is highly miscible with the developing solvent. Examples of IT solution include water. Methyl alcohol, ethyl alcohol, isoflobil alcohol, toluene, xylene, methyl alcohol, methyl ethyl ketone, methyl cellosol,
Examples include ethyl cellosolve.

The photosensitive po-IJ imide thread resin precursor according to the present invention may be any negative-working material that has been known up to now.

For example, JP-A-49-17374, JP-A-49-1 1
5541, JP-A-54-88116, JP-A-5←14
5794, JP-A-55-155347, JP-A-55-4
An example of this is the photosensitive poly-11imide resin precursor disclosed in No. 5748.

below. The present invention will be explained using specific examples.

Example 1 The photosensitive IJ imide precursor of the composition shown in Table 1 was
It was spin-coated onto an I-con wafer and kept dry at 70°C for 60 minutes to form a coating film with a N thickness of about 5 μm. This coating film was exposed to a high-pressure mercury lamp for 1 minute using a prescribed photomask. The ultraviolet ray moderation at this time is 10mW/3' (365℃m).
fc 0 next, 11 tons of N-methyl-2-pyro is 902,
1i for 2 minutes at room temperature with a developer consisting of 102 ion-exchanged water.
f! Developed by soaking and developing, then immersed in ethyl alcohol for 1 minute. Then 117 seconds. The M shore here was approximately 4.5 μm. Next, heat at 200℃ for 30 minutes. 20 per minute after I&!
A final cured film was obtained by heat treatment at 350°C for 30 minutes in a N2 atmosphere, and the film thickness was approximately 2.7 μm. After the Gengen process, the above-mentioned Katsukou film was observed with a 500x magnification magnification microscope, and no cracks were observed.
The fc final cured film had excellent electrical properties and heat resistance as an insulating film.

Example 2 In the same manner as in Example 1 (7), a photosensitive polyimide precursor having the composition shown in Table N111 was used to obtain a photosensitive film of about 5 μm.
Next, 75 tons of N-methyl-2-pyro I+ton.

2 at room temperature using a developer consisting of 25p of ion-exchanged water.
Developed by immersion for 1 minute, then immersed in ethyl alcohol for 1 minute, rinsed again, and the film thickness after rinsing was approximately 4.7 μm.
When observed with a metallurgical microscope at 500x magnification, there were no cracks. Next, at 200℃ for 60 minutes, and then at 20℃ per minute.
! When heat treated for 30 minutes at 350°C in a N2 atmosphere, approximately 2
．． A final cured film of 9μm was obtained, and this film had excellent heat resistance and excellent electrical properties.

Example 3 A photosensitive film of about 5 μm was obtained in the same manner as in Example 1 using a photosensitive boimide precursor having the composition shown in Na1 in the table. Next, 50 tons of N-methyl-2-pyroυton.

The film was developed by immersion at a comfortable temperature for 2 minutes using a developing solution consisting of 50 y of ion-exchanged water, and then immersed in ethyl alcohol for 1 minute for IJ rinsing. The membrane after IJ is approximately 4.6μ
m, and no cracks were observed when observed with a metallurgical microscope at 500x magnification. Next, heat treatment was performed at 200° C. for 60 minutes and then at 350° C. for 30 minutes in an N2 atmosphere of 20 Il/min, resulting in a final cured film of about 2.8 μm. This film had excellent heat resistance and excellent thermal properties.

Example 4 A coating film having a film thickness of about 8 μm after exposure was obtained using a photosensitive bo1]imide precursor having the T composition shown in Floor 2 of the table.

This KojikomeiN, N-dimethylacetamide is 75t.

2 at room temperature using a developer consisting of 25# ion-exchanged water.
The film was developed by dipping for one minute, and then rinsed by dipping in acetone for one minute. The film thickness after rinsing is approximately 7μm, 5θO
When observed with a metallurgical microscope at a magnification of 200℃, no cracks were observed.
A final cured film of approximately 4 μm was obtained by heat treatment at 350° C. for 50 minutes in a 2 atmosphere. This film has excellent heat resistance and electrical properties.Example 5 A coating film of about 4 μm was made in the same manner as in Example 1 using the photosensitive boimide precursor shown in Na3 in the table. I got it. This coating film is coated with a high-pressure mercury lamp through a photomask on the PJT foot.
The light was heavy for 0 minutes. The UV intensity at this time was 15mW/c
fc at m' (565°C m). Next, N-methyl-2-
75g of pyrrolidone, 25g of ion exchange water. The film was developed by immersing it in a developer consisting of the following at room temperature for 2 minutes, and then immersing it in ethyl alcohol for 1 minute for 11 seconds. The film thickness after II rinsing was about 5.9 μm, and there were no cracks when observed under a metallurgical microscope with a magnification of 500 times. Then 3 at 200℃
When the film was heated for 60 minutes at 350° C. in an N2 atmosphere at 2 on/min, a final cured film of about 2.1 μm was obtained, and this film was excellent in both heat resistance and electrical properties.

Comparative Example 1 In the same manner as in Comparative Example 1, a coating film having a thickness of about 3 μm after exposure was obtained using a photosensitive polyimide precursor having the composition shown in Table 1. This stick light film was developed by immersing it at room temperature for 2 minutes in a developer consisting of 8 g of N,N-dimethylacetamide and 2 parts of methyl alcohol, and then immersed in methyl alcohol for 1 minute to develop it. It was also observed with the naked eye that cracks had formed and parts of the film had fallen off.

The final cured film obtained by heat treatment under the same conditions as in Example 1 was not suitable for practical use as an insulating film and had a diameter of more than 60 μm. The photosensitive polyimide precursor coating can be developed without any cracks or holes. For this reason, in the semiconductor integrated circuit I/'1, a film with a thickness of 2 μm or more can be obtained as an interlayer insulating film for multilayer wiring in a hybrid integrated circuit, etc. ! The relationship performance has improved dramatically and the agent patent attorney Susuki 1) Toshiyuki

Claims (1)

[Scope of Claims] An aprotic polar solvent t is used in a developer used to form a polyimide resin having a predetermined pattern from a photosensitive polyimide resin precursor. A developer for photosensitive heat-resistant resins, characterized in that it consists of 10% by weight or more and 50% by weight or less of water, and an organic solvent added as necessary.