JP2001154356A - Positive type photosensitive resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive type photosensitive resin composition excellent in low film thickness reducing property. SOLUTION: The positive type photosensitive resin composition comprises 100 pts. wt. polyamide of formula 1 [where X is a tetravalent aromatic group; Y is a divalent aromatic group; Z is a group of formula 2 (where R1 and R2 are each a divalent organic group; and R3 and R4 are each a monovalent organic group); E is an aliphatic, alicyclic or cyclic compound having at least one alkenyl or alkynyl group; (a) and (b) show mole fraction, a+b=100 mol%, (a) is 60.0-100.0 mol%, (b) is 0-40.0 mol%; and (n) is 2-500], 1-100 pts.wt. photosensitive diazoquinone compound and 0.01-20 pts.wt. novolak type phenolic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photosensitive resin composition having excellent low film loss.

[0002]

2. Description of the Related Art Conventionally, a polyimide resin having excellent heat resistance and excellent electrical and mechanical properties has been used for a surface protective film and an interlayer insulating film of a semiconductor element. There is a demand for remarkable improvement in heat cycle resistance and heat shock resistance due to the increase in size, increase in size, thinner and smaller package, shift to surface mounting by solder reflow, etc., and further high-performance resin is required. It has become On the other hand, a technique for imparting photosensitivity to the polyimide resin itself has recently attracted attention, and the use of this technique can simplify a part of the pattern forming process, and has the effect of shortening the process and improving the yield. Requires a solvent such as N-methyl-2-pyrrolidone, which is problematic in terms of safety and handling.

Therefore, recently, a positive photosensitive resin which can be developed with an alkaline aqueous solution has been developed. For example, Japanese Patent Publication No. 1-46862 discloses a positive photosensitive resin composed of a polybenzoxazole precursor and a diazoquinone compound. It has high heat resistance, excellent electrical properties and fine workability, and has the potential not only as a wafer coat but also as an interlayer insulating resin.

When such a photosensitive resin is used as a surface protective film of a semiconductor element, a part of a pattern forming process can be simplified, and there is an effect of shortening the process and improving the yield. However, with the recent trend toward higher integration of devices and miniaturization of packages, the design rules for patterns have been miniaturized, and a surface protective film having a high resolution has been required. Especially when the line width and line interval of the processing pattern are narrow,
It is very difficult to process the surface protection film which is reduced in film thickness during development because the shape of the remaining line width is incomplete or collapsed.

Generally, the photosensitive resin such as polyimide used as a surface protective film is coated on a wafer and then subjected to an exposure and development process to reduce the film thickness. When the line width and the line interval of the processing pattern are small, the developer is etched not only in the depth direction of the resin film but also in the lateral direction, so that the shape of the remaining line width is considered to be affected. Therefore, if it is determined that processing with a surface protective film such as polyimide is impossible, a process of processing the target pattern using a photoresist, etching the inorganic film, and removing the photoresist film is required. Becomes

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positive photosensitive resin composition which is excellent in low film loss.

[0007]

According to the present invention, there is provided a compound represented by the general formula (1):
100 parts by weight of a polyamide, 1 to 100 parts by weight of a photosensitive diazoquinone compound, and 0.01 to phenol resin
It is a positive photosensitive resin composition comprising 20 parts by weight.

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A more preferred embodiment is a positive photosensitive resin composition in which the phenol resin is a novolak type phenol-formaldehyde resin. Further, the present invention is a semiconductor device manufactured using the positive photosensitive resin composition.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyamide of the formula (1) comprises bisaminophenol having the structure of X, dicarboxylic acid having the structure of Y, and acid anhydride having the structure of E. When heated at up to 400 ° C., the ring is dehydrated and closed to change to a heat-resistant resin called polybenzoxazole.

X of the polyamide (1) of the present invention is, for example,

Embedded image Etc., but are not limited to these.

Among them, particularly preferred are:

Embedded image It is more chosen.

In addition, Y in the formula (1) is, for example,

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However, the present invention is not limited to these. Particularly preferred among these are:

[0014]

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[0015] It is more selected. Also, E of the formula (1)
Is, for example,

[0016]

Embedded image And the like, but are not limited thereto.

Among them, particularly preferred are:

Embedded image It is more chosen.

According to the present invention, a polyamide is synthesized by reacting a dicarboxylic acid derivative having the structure of Y with a bisaminophenol having the structure of X, and then at least one alkenyl group or alkynyl group represented by E in the formula (1) is obtained. The terminal amino group is capped with an acid anhydride having the acid anhydride.

Further, Z in the formula (1) is, for example,

Embedded image Etc., but are not limited to these.

Z in the formula (1) is used when particularly good adhesion is required to a substrate such as a silicon wafer, for example, and its use ratio b is up to 40.0 mol%. . If it exceeds 40.0 mol%, the solubility of the resin is extremely reduced, and undeveloped portions (scum) are generated, so that pattern processing cannot be performed. In using these X, Y, E, and Z, one type or a mixture of two or more types may be used.

The photosensitive diazoquinone compound used in the present invention is a compound having a 1,2-benzoquinonediazide or 1,2-naphthoquinonediazide structure, and is disclosed in US Pat. Nos. 2,772,972 and 2,797, 21
No. 3,669,658. For example, the following are mentioned.

[0022]

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[0023]

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Among these, the following are particularly preferred in terms of high sensitivity and high residual film ratio.

[0025]

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The photosensitive diazoquinone compound is added to the polyamide in an amount of 1 to 100 parts by weight of the polyamide.
When the amount is less than 1 part by weight, the patterning property of the resin is poor. On the contrary, when the amount exceeds 100 parts by weight, not only the sensitivity is significantly reduced, but also the tensile elongation of the film is significantly reduced. I do. A semiconductor device in which a film having a small tensile elongation is applied to the element surface is not preferable because reliability such as thermal stress deteriorates.

A dihydropyridine derivative can be added to the positive photosensitive resin composition of the present invention, if necessary, to enhance the photosensitive characteristics. Examples of the dihydropyridine derivative include, for example, 2,6-dimethyl-3,5-diacetyl-4- (2′-nitrophenyl) -1,4-dihydropyridine, 4- (2′-nitrophenyl) -2,6-dimethyl -3,5-dicarbethoxy-1,4-dihydropyridine, 4- (2 ', 4'-dinitrophenyl) -2,
6-dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine and the like can be mentioned.

The present invention is characterized in that a phenol resin is added to the polyamide represented by the general formula (1) and the photosensitive diazoquinone compound. The phenolic resin has a dissolution inhibiting effect at the unexposed portion of the photosensitive diazoquinone compound, while the exposed portion has a dissolution promoting action to generate a contrast and form a pattern. The phenolic resin used in the present invention is not particularly limited and is a commercially available phenolic resin, and is obtained by adding a non-thermally reactive novolak-type phenolic resin obtained by adding an acid-based catalyst to phenol and formalin to form a phenol resin having a general formula A low film-thinning property can be imparted to the polyamide represented by (1). Phenols can be synthesized by, for example, phenol, o-cresol, m-cresol, p-cresol, xylenol, catechol, resorcinol, hydroquinone, biphenol, ethylphenol, butylphenol, octylphenol and the like. Is preferably a novolak-type phenol-formaldehyde resin represented by the following formula (2).

[0029]

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The amount of the phenol resin to be mixed with the polyamide (1) is 0.01 to 2 parts by weight based on 100 parts by weight of the polyamide.
When the amount is 0 part by weight and the amount is less than 0.01 part by weight, there is no effect of suppressing the film loss by mixing. Conversely, if the amount exceeds 20 parts by weight, a problem arises that undeveloped portions are generated at pattern corners opened after development.

In the present invention, these components are dissolved in a solvent and used in the form of a varnish. Examples of the solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-
Dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene Glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxypropionate, etc., may be used alone or in combination.

In the method of using the positive photosensitive resin composition of the present invention, the composition is first applied to a suitable support, for example, a silicon wafer, a ceramic substrate, an aluminum substrate or the like.
In the case of a semiconductor device, the amount of coating is 0.1 μm for the final film thickness after curing.
It is applied so as to have a thickness of 1 to 20 μm. When the thickness is 0.1 μm or less, it is difficult to sufficiently exert the function as a protective surface film of the semiconductor element, and when it is 20 μm or more, it becomes difficult to obtain a fine processing pattern, In addition, processing takes time and the throughput is reduced.
Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating. Next, after pre-baking at 60 to 130 ° C. to dry the coating film, a desired pattern shape is irradiated with actinic radiation. As the actinic radiation, X-rays, electron beams, ultraviolet rays, visible rays and the like can be used, but those having a wavelength of 200 to 500 nm are preferable. Next, a relief pattern is obtained by dissolving and removing the irradiated portion with a developer. Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, and di-n. Secondary amines such as propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine,
An aqueous solution of an alkali such as a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide, and an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as alcohol such as methanol or ethanol or a surfactant. Can be suitably used. As a developing method, a system such as spray, paddle, immersion, and ultrasonic wave can be used. Next, the relief pattern formed by development is rinsed. As the rinse liquid,
Use distilled water. Next, heat treatment is performed to form an oxazole ring, and a final pattern having high heat resistance is obtained.

The positive photosensitive resin composition according to the present invention comprises
It is not only useful for semiconductors, but also useful as interlayer insulation for multilayer circuits, cover coats for flexible copper-clad boards, solder resist films, liquid crystal alignment films, etc., but is particularly useful and highly reliable when used in semiconductor devices. A semiconductor device can be obtained. As a method for manufacturing a semiconductor device, a conventionally known method can be used.

[0034]

The present invention will be described below in detail with reference to examples. << Example 1 >> * Synthesis of polyamide Dicarboxylic acid derivative 443. obtained by reacting 1 mol of diphenyl ether-4,4'-dicarboxylic acid with 2 mol of 1-hydroxy-1,2,3-benzotriazole.
2 g (0.9 mol) and hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane 36
6.3 g (1.0 mol) was put into a four-neck separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet tube, and N-methyl-2-pyrrolidone was 3000 g.
And dissolved. Then use an oil bath at 75 ° C
For 12 hours. Next, 5-norbornene-2,3- dissolved in 500 g of N-methyl-2-pyrrolidone.
32.8 g (0.2 mol) of dicarboxylic anhydride were added,
The reaction was further stirred for 12 hours to complete the reaction. After the reaction mixture was filtered, it was poured into a mixed solution of water / methanol = 3/1, the precipitate was collected by filtration, sufficiently filtered with water, dried under vacuum, and represented by the desired general formula (1). , X is the following formula X-1,
Y is the following formula Y-1, E is the following formula E-1, a = 100, b
= 0 (polyamide (A-1)).

* Preparation of positive photosensitive resin composition 100 g of synthesized polyamide (A-1), 25 g of diazoquinone (Q-1) having a structure of the following formula, and P-1 of the following formula
Phenol-formaldehyde resin having the structure
3 g was dissolved in 200 g of N-methyl-2-pyrrolidone,
Stir for 3 hours. Then stop stirring and leave at room temperature.
When the appearance was visually observed after a lapse of time, no bubbles were observed. Thereafter, the mixture was filtered through a 0.2 μm Teflon filter to obtain a photosensitive resin composition.

* Characteristic evaluation After coating this positive photosensitive resin composition on a silicon wafer by using a spin coater, it was dried at 120 ° C. for 4 minutes on a hot plate to form a coating film having a thickness of about 7.0 μm. Obtained. In addition, an i-line stepper exposure machine NSR-22
Exposure was performed using a 05i12C (manufactured by Nikon Corporation) through a reticle at an exposure of 100 to 800 mJ / cm ²
The exposed portion was dissolved and removed by immersion in a 2.38% aqueous solution of tetramethyl hydroxide for 60 seconds, followed by rinsing with pure water for 30 seconds to form a pattern. When the film thickness after development was measured, it was 6.45 μm, and the amount of film reduction during development was 0.55 μm. When this wafer was observed with a microscope, the film thickness of 50 μm □ became 0 at an exposure dose of 300 mJ / cm ² . The exposure amount at this time is defined as Eth sensitivity. The pattern corner at 300 mJ / cm ² was observed, and it was confirmed that there was no development residue and a good pattern was formed. Next, when the exposure amount is 400 mJ /
In cm ² , the dimension of the remaining portion (line portion) of the 5 μm line & space repetition pattern was measured with a measuring microscope and found to be 2.5 μm.

Example 2 A prototype was produced and evaluated in the same manner as in Example 1 except that the amount of the phenol-formaldehyde resin was changed to 1.0 g. Example 3 In the synthesis of the polyamide in Example 1, 132.8 g (0.8 mol) of terephthalic acid and 33.2 g (0.2 mol) of isophthalic acid were used instead of 1 mol of diphenyl ether-4,4'-dicarboxylic acid. ) To react with 2 moles of 1-hydroxy-1,2,3-benzotriazole to obtain a dicarboxylic acid derivative 36
0.4 g (0.9 mol) of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane 3
66.3 g (1.0 mol), and represented by the general formula (1), wherein X is the following formula X-1, Y is the following formula Y-2 and Y-
3, a polyamide was synthesized in which E = a = 100 and b = 0 in the following formula E-1. Example 4 In the synthesis of the polyamide in Example 1, 132.8 g (0.8 mol) of terephthalic acid and 33.2 g (0.2 mol) of isophthalic acid were used instead of 1 mol of diphenyl ether-4,4′-dicarboxylic acid. ), And a dicarboxylic acid derivative obtained by reacting with 2 mol of 1-hydroxy-1,2,3-benzotriazole.
4 g (0.9 mol) and hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane 36
6.3 g (1.0 mol) and represented by the general formula (1), wherein X is the following formula X-1, Y is the following formula Y-2 and Y-
3, a polyamide was synthesized in which E = a = 100 and b = 0 in the following formula E-1. Example 5 In the synthesis of the polyamide in Example 1, hexafluoro-2,2-bis (3-amino-4-
3,3'- instead of (hydroxyphenyl) propane
Using 280.0 g (1.0 mol) of diamino-4,4'-dihydroxydiphenyl sulfone, represented by the general formula (1), X is the following formula X-2, Y is the following formula Y-1, and E is the following formula: A polyamide consisting of a = 100 and b = 0 in the following formula E-1 was synthesized, and the others were subjected to the same trial manufacture and evaluation as in Example 1. Example 6 In the synthesis of the polyamide in Example 1, 348.0 g (0.95 g) of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane was used.
Mol), and 12.4 g (0.05 mol) of 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane was added instead, and represented by the general formula (1). X is the following formula X-1, Y is the following formula Y-1, Z is the following formula Z-1, and E is the following formula E-1 to synthesize a polyamide consisting of a = 95 and b = 5; The same trial manufacture and evaluation as in Example 1 were performed.

Comparative Example 1 A prototype was produced and evaluated in Example 1 without adding a phenol-formaldehyde resin. << Comparative Example 2 >> A trial production and evaluation were performed in the same manner as in Example 1 except that the blending amount of the phenol-formaldehyde resin was changed to 0.005 g. << Comparative Example 3 >> A trial production and evaluation were performed in the same manner as in Example 1 except that the amount of the phenol-formaldehyde resin was changed to 30 g. << Comparative Example 4 >> A trial production and evaluation were performed in the same manner as in Example 1 except that the amount of the phenol-formaldehyde resin was changed to 30 g.

The formulations and evaluation results of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Tables 1 and 2.

[Table 1]

[0040]

[Table 2]

[0041]

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[0042]

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[0043]

According to the present invention, it is possible to obtain a positive photosensitive resin composition excellent in low film-thinning property without lowering the sensitivity.

Claims (6)

[Claims] 1. A polyamide 10 represented by the general formula (1)
A positive photosensitive resin composition comprising 0 parts by weight, 1 to 100 parts by weight of a photosensitive diazoquinone compound, and 0.01 to 20 parts by weight of a phenol resin. Embedded image 2. X in the polyamide of the general formula (1)
The positive photosensitive resin composition according to claim 1, wherein is selected from the following. Embedded image 3. Y in the polyamide of the general formula (1)
Is selected from the following: The positive photosensitive resin composition according to claim 1 or 2, wherein Embedded image 4. The polyamide of the general formula (1)
Is selected from the following: The positive photosensitive resin composition according to claim 1, 2 or 3. Embedded image 5. The positive photosensitive resin composition according to claim 1, wherein the phenol resin is a novolak phenol-formaldehyde resin represented by the general formula (2). Embedded image 6. A semiconductor device manufactured using the positive photosensitive resin composition according to claim 1.