KR100244982B1 - Photosensitive ployimide of low shrinkage - Google Patents

Abstract

The present invention relates to a siloxane polyimide precursor composition comprising a tetracarboxylic dianhydride of formula (1), an aromatic diamine of formula (2) and a photoreactive monomer in an organic solvent. The photoreactive monomer is composed of a compound having a ring-opening polymerization cyclic monomer and a photocrosslinkable acrylic photosensitive group, and the content ratio of these components is in the range of 10:90 to 90:10.

H ₂ NR ₂ -NH ₂

Wherein R ₂ is an aromatic or aliphatic cyclic group and X is a photosensitive compound having a saturated aliphatic or unsaturated aliphatic group.

A photoinitiator, a sensitizer, a polymerization inhibitor and / or a colloidal inorganic additive may be further added to the polyimide precursor composition to improve photosensitivity, thermal stability and hardness of the film.

Description

Low shrinkage photosensitive polyimide precursor composition

The present invention relates to a low shrinkage photosensitive polyimide precursor composition. More specifically, the present invention relates to a low shrinkage photosensitive polyimide precursor composition composed of tetracarboxylic dianhydride, aromatic diamine and photoreactive monomer.

Recently, in the semiconductor device field mainly on semiconductors and liquid crystal display devices, as the movement of high integration, high density, high reliability, and high speed of electronic devices are rapidly spreading, active researches are being made to take advantage of organic materials that are easy to process and high purity. It's going on. However, in order for the organic polymer to be used in these fields, it must be thermally stable in a process requiring 200 ° C. or more during device fabrication. In addition to the excellent electrical properties such as high heat resistance, excellent mechanical strength, low dielectric constant and high insulation, the polyimide resin has good planarization characteristics of the coating surface, very low impurity content which degrades the reliability of the device, and can easily form fine shapes. There is a resin most suitable for the above purpose. A general method for synthesizing polyimide is a two-stage condensation polymerization, in which a diamine component and an acid dianhydride are polymerized in a polar organic solvent such as NMP (N-methyl-2-pyrrolidone), DMAc (demethylacetamide) or DMF (dimethylformamide) to form a polyimide precursor. A solution is obtained, which is coated on a silicon wafer or glass and then cured by heat treatment to obtain a polyimide film. Polyimide products for commercialized electronic materials are supplied in the form of polyimide precursor solutions or polyimide films, and are mainly supplied in the polyimide precursor solution state in the semiconductor device field. In resin-encapsulated LSIs, cracks in the passivation film of chips or damage to metal wiring may occur due to the thermal shrinkage of the resin after encapsulation and the thermal stress caused by the difference between the chip and the thermal expansion coefficient of the resin. . This problem is solved by using a polyimide between the chip and the encapsulant as a buffer layer, and a polyimide film thickness of 10 μm or more plays a buffer role. As the thickness of the coating film becomes thicker, the buffer effect is improved to improve the yield of semiconductor products. Can be. Polyimides require the formation of micro holes (via holes) such as inter-electrode connections and wire bonding pads. In order to form a fine pattern of polyimide, a method of coating a photoresist on an existing polyimide and etching is widely used, but recently, application of a photosensitive polyimide having a photosensitive function to the polyimide has been attempted.

Conventional non-photosensitive polyimide requires an etching process to process holes using a separate photoresist for wire-bonding and metal wiring, but the use of photosensitive polyimide If it is possible to omit some of the processes can greatly increase the productivity. Practical photosensitive polyimide was developed by Rubner et al. Of Siemen (US-A-3957512). This is a form in which the photosensitive group is bonded to the polyamic acid as a polyimide precursor through an ester bond. When the photosensitive polyimide precursor solution is coated on a substrate to form a film and exposed to ultraviolet light, photopolymerization occurs in the exposed portion to form a crosslinked structure. In this state, the unexposed portion is removed during development with the organic solvent, and the final heat treatment causes the ester-bonded photosensitive component to be decomposed and removed at the same time as the imidization reaction to obtain a desired pattern of polyimide. Meanwhile, Toray Corp., Japan, has developed a photosensitive polyimide in which a compound having a photosensitive group and an amino component in a polyamic acid is ion-bonded (US-A-4243743). Such photosensitive polyimide has advantages in that it is easy to manufacture and generates less harmful by-products than conventional photosensitive polyimide.

However, in order to manufacture the photosensitive polyimide by the above method, the photosensitive acrylic compound is introduced into the high molecular weight polyimide precursor in the form of a covalent bond or an ionic bond to form a photosensitive pattern by photocrosslinking. It is difficult to obtain accurate resolution due to the volume shrinkage of, and it is a major cause of cracking during the pattern formation process of the lack of adhesion between the wafer and the polyimide precursor, the development and the rinsing process.

Accordingly, the present inventors use the radical ring-opening polymerization monomer as part of the photosensitive composition to prevent shrinkage due to the photocuring reaction of the acrylic compounds, thereby improving accuracy, adhesion between the polyimide precursor and the wafer, and the degree of cracking during the pattern forming process. It came to manufacture the photosensitive polyimide precursor composition which can be reduced.

The technical problem to be achieved by the present invention is to prevent the shrinkage due to the photocuring reaction of the acrylic compounds by using a photoreactive monomer having a compound 10: 90 to 90: 10 ratio of the ring-opening polymerization cyclic monomer and a photocrosslinkable acrylic photosensitive group It is to provide a low shrinkage photosensitive polyimide precursor composition.

Another technical problem to be achieved by the present invention is to prevent the shrinkage of acrylic compounds by using a photoreactive monomer having a compound ring ratio of 10:90 to 90:10 having a ring-opening-type cyclic monomer and a photocrosslinkable acrylic photoreceptor, thereby preventing resolution and adhesiveness. It is to provide a photosensitive polyimide precursor composition that has been improved and cracking is reduced.

The above and other technical problems of the present invention can be achieved by the present invention described below.

The present invention relates to a siloxane polyimide precursor composition comprising a tetracarboxylic dianhydride of formula (1), an aromatic diamine of formula (2) and a photoreactive monomer in an organic solvent. The photoreactive monomer is composed of a compound having a ring-opening polymerization cyclic monomer and a photocrosslinkable acrylic photosensitive group, and the content ratio of these components is in the range of 10:90 to 90:10.

Formula 1

Formula 2

H ₂ NR ₂ -NH ₂

Wherein R ₂ is an aromatic or aliphatic cyclic group and X is a photosensitive compound having a saturated aliphatic or unsaturated aliphatic group.

In the organic solvent, an aromatic tetracarboxylic dianhydride of Formula 3 may be used as a pretreatment with alcohol, in which case a part of the aromatic tetracarboxylic dianhydride of Formula 1 is converted into a compound of Formula 3.

Wherein R ₁ is an aromatic or aliphatic cyclic group, and X is a photosensitive compound having a saturated aliphatic or unsaturated aliphatic group.

Each of these components is described in detail below.

Tetracarboxylic dianhydride is classified into aromatic tetracarboxylic dianhydride and alicyclic dianhydride. The tetracarboxylic dianhydride includes cyclopentanetetracarboxylic dianhydride, bicyclopentanetetracarboxylic dianhydride, cyclopropanetetracarboxylic dianhydride, methyl Methylcyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride (3,3', 4,4'-benzophenonetetracarboxylic dianhydride), pyromellitic dianhydride Water (pyromellitic acid dianhydride), 3,4,9,10-perylenetetracarboxylic dianhydride (3,4,9,10-perylenetetracaboxylic dianhydride), 4,4-sulfonyldiphthalic dianhydride (4,4- sulfonyldiphthalic dianhydride), 3,3'4,4'-biphenyl tetracarboxylic dianhydride (3,3'4,4'-biphenyltetracarboxylic dianhydride), 1,2,5,6-naphthalenetetracarboxylic dianhydride (1,2,5,6-naphthalenetetraca boxylic dianhydride), 2,3,6,7-naphthalenetetracarboxylic dianhydride (2,3,6,7-naphthalenetetracaboxylic dianhydride), 1,4,5,8-naphthalenetetracarboxylic dianhydride (1, 4,5,8-naphthalenetetracaboxylic dianhydride), 2,3,5,6-pyridinetetracarboxylic dianhydride (2,3,5,6-pyridinetetracaboxylic dianhydride), m-terphenyl-3,3 ', 4, 4 ',-tetracarboxylic dianhydride (m-terphenyl-3,3', 4,4 ',-tetracaboxylic dianhydride), p-terphenyl-3,3', 4,4 ',-tetracarboxylic acid Dianhydrides (p-terphenyl-3,3 ', 4,4',-tetracaboxylic dianhydride), 4,4-oxydiphthalic dianhydride, 1,1,1,3,3, 3, -hexafluoro-2,2-bis (2,3 or 3,4-dicarboxyphenoxy) phenylpropane dianhydride (1,1,1,3,3,3, -hexafluoro-2,2- bis (2,3 or 3,4-dicarboxyphenoxy) phenylpropane dianhydride), 2,2-bis [4- (2,3 or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride (2,2-bis [ 4- (2,3 or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride), and 1,1,1,3,3,3,- Safluoro-2,2-bis [4- (2,3 or 3,4-dicarboxyphenoxy) phenol] propane dianhydride (1,1,1,3,3,3, -hexafluoro-2,2 -bis [4- (2,3 or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride).

Aromatic diamines that can be used in the present invention include m-phenylene diamine, p-phenylenediamine, m-xylylenediamine, 1,5-diamino Naphthalene (1,5-diaminonaphthalene), 3,3'-dimethylbenzidine, 4,4- (or 3,4'-, 3,3'-, 2,4'- or 2 , 2 '-) diaminodiphenylmethane (4,4- (or 3,4'-, 3,3'-2,4'- or 2,2'-) diaminodiphenylmethane), 4,4- (or 3 , 4'-, 3,3'-, 2,4'- or 2,2 '-) diaminodiphenylether (4,4- (or 3,4'-, 3,3'-, 2,4 '-or 2,2'-) diaminodiphenylether), 4,4- (or 3,4'-, 3,3'-, 2,4'- or 2,2 '-) diaminodiphenylsulfide (4 , 4- (or 3,4 '-, 3,3'-2,4' or-2,2 '-) diaminodiphenylsulfide), 4,4- (or 3,4'-, 3,3'-, 2 , 4'- or 2,2 '-) diaminodiphenylsulfone (4,4- (or 3,4'-, 3,3'-2,4 'or-2,2'-) diaminodiphenylsulfide), 1 , 1,1,3,3,3, -hexafluoro-2,2-bis (4-aminophenyl) propane ((1,1,1,3,3,3, -hexafluoro-2,2-bis (4-aminophenyl) propane), 2,2-bis (4- (4-aminophenoxy) phene Yl) propane (2,2-bis (4- (4-aminophenoxy) phenyl) propane), 4,4-benzophenonediamine, 4,4'-di- (4-aminophenoxy ) Phenyl sulfone (4,4'-di- (4-aminophenoxy) phenylsulfone), 3,3-dimethyl-4,4-diaminodiphenylmethane, 4,4 4'-di- (3-aminophenoxy) phenylsulfone (4,4'-di- (3-aminophenoxy) phenylsulfone), 2,4-diaminotoluene, 2,5-dia Minotoluene (2,5-diaminotoluene), 2,6-diaminotoluene, benzidine, o-tolidine, 4,4'-diaminoterphenyl ( 4,4'-diaminoterphenyl), 2,5-diaminopyridine, 4,4'-bis (p-aminophenoxy) biphenyl (4,4'-bis (p-aminophenoxy) biphenyl), and hexahydro-4,7-methanoindanylene dimethylene diamine.

In addition, siloxane diamine or siloxane dianhydride components may be used to improve adhesion to substrates such as wafers and the like.

In the present invention, the siloxane diamine or siloxane dianhydride is used in an amount of 1 to 10 mol% based on the monomers. If the amount of the siloxane-based diamine is less than 1 mol%, the adhesive strength is lowered, and if more than 10 mol% is used, the thermal properties are poor.

Organic solvents used in the preparation of the polyamic acid include N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, hexamethylphosphoric triamide, gamma-butyrolactone And common organic solvents.

A photoreactive monomer component, a photopolymerization initiator, a photosensitizer and the like may be added to impart a photosensitive function to the polyimide precursor solution obtained above. As the photoreactive monomer component used in the present invention, a compound having a ring-opening polymerization type cyclic monomer component and an addition type carbon-carbon unsaturated group is used.

As the ring-opening polymerization type cyclic monomer added to the polyimide precursor solution, a vinyl cyclopropane component of Formula 4a, a cyclic ketene acetal component of Formula 4b, and a cyclic acrylate component of Formula 4c and Formula 4d may be used. Can be.

Wherein X and Y are halogen compounds, R 'is an aliphatic group compound, and Z is H or CH ₃ .

Examples of the compound having a photoreactive addition type carbon-carbon unsaturated group added to the polyimide precursor solution include N-methylacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, and N, N-dimethylacrylamide. , N, N-diethylacrylamide, N-acryloyl yl morpholine, N-vinylpyrrolidone and the like. There is no restriction on the compound including the carbon-carbon unsaturated group used in the present invention. However, when the unsaturated group is bonded to an amino group, the carboxyl group of the polyamic acid is preferably bonded in the form of a salt, and the photoreactivity is superior to that of the photoreactive compound containing no amino group. Examples of the compound including both the carbon-carbon unsaturated group and the amino group having photoreactivity include N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate, N, N-diethylaminopropylacrylate, N, N-dimethylaminobutylacrylate, and the like. Instead of acrylate, 2-vinylpyridine, 4-vinylpyridine, arylamine, 2-methylarylamine, diarylamine, etc. There is no restriction on these compounds.

The use ratio of the ring-opening polymerization monomer component and the compound having an additional type carbon-carbon unsaturated group in the photoreactive monomer component used in the present invention is preferably in the range of 10:90 to 90:10.

Alcohol compounds used for R ₁ OH in the present invention include methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol and allyl alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacryl. There are alcohols having a photoreceptor such as a rate.

Photopolymerization initiators that can be used in the present invention include 2,6-di- (p-azidobenzal) -4-methylcyclohexanone (2,6-di- (p-azidobenzal) -4-methylcyclohexanone), and Bisazide compounds such as 2,6-di- (p-azidobenzal) -cyclohexanone, benzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylaminobenzophenone), 4,4-bis (diethylaminobenzophenone), 4,4-dichlorbenzophenone, 4-benzoyl-4'-methyldiphenylketone, dibenzylketone, florenone, 2,2'diethoxyacetophenone , 1-phenyl-1,2-butanedione-2- (o-ethoxycarbonyl) oxime (1-phenyl-butandione-2- (o-ethoxycarbonyl) oxime), 1,3-diphenyl-propanedione- 2- (o-ethoxycarbonyl) oxime (1,3-diphenyl-propandione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanedione-2- (o-benzyl) oxime ( 1-phenyl-3-ethoxy-propandione-2- (o-benzyl) oxime), miharazketone, N-phenylglycidine, 3-phenyl-5-isoxazolone, 1-hydroxycyclohexylphenylketone, 2-methyl- (4- (methyltea ) Phenyl) -2-morpholino-1-propanone, naphthalenesulfonylchloride, quinolinesulfonyl chloride, N-phenylthioacridone, 4,4'-azobisisobutyronitrile, diphenyldisulfide , Benzthiazoledisulfide, triphenylpolspin, campolquinone, carbon tetrabromide, tribromophenylsulfone, and benzoyl peroxide; and eosin and methylene blue containing reducing agents such as ascorbic acid and triethanolamine; It can be used in combination with the same photoreducing dye The photoinitiator can be used in combination of one or two or more.

The quantity of the photoinitiator contained in the siloxane polyimide precursor of this invention is 0.1-30 weight% based on a polyamic acid resin, and 2-15 weight% is preferable. If the amount of the photopolymerization initiator is 0.1% by weight or less, the photosensitivity of the composition is lowered.

In the present invention, a sensitizer may be used to improve photosensitivity. Such sensitizers include 2,5-bis (4'-diethylaminobenzal) cyclopentanone, 2,6-bis (4'-dimethylaminobenzal) cyclohexanone, miharazketone, 4,4'-bis ( Diethylamino) benzophenone, 4,4'-bis (dimethylamino) chalcone, 4,4'-bis (diethylamino) chalcone, p-dimethylaminobenzylidene indanone, 2- (p-dimethylaminophenylvinyl Ene) -isonnaphthothiazole, 2- (p-dimethylaminophenylvinylene) benzothiazole, 1,3-bis (4'-dimethylaminobenzal) acetone, 1,3-bis (4'-diethylamino Benzal) acetone, 3,3'-carbonyl-bis- (7-diethylaminocumalin), N-phenyldiethanoldiamine, N-tolyldiethanolamine, N-phenylethanoldiamine, dimethylaminobenzoic acid isoamyl, 3-phenyl-5-isoxazolone, 1-phenyl-5-benzoylthio-tetrazole, 1-5-ethoxycarbonylthio-tetrazole and the like. One or more sensitizers may be used, and 0.1 to 30% by weight based on the polyamic acid is preferably 0.5 to 15% by weight. If the added amount of the sensitizer is 30% by weight or more, the thickness of the film decreases and the mechanical properties deteriorate during curing of the film. If the amount is less than 0.1% by weight, the photosensitivity of the composition is lowered.

When preserving the siloxane polyimide precursor of the present invention, a thermal polymerization inhibitor may be added to improve thermal stability. Examples of the thermal polymerization inhibitor include hydroquinone, N-nitrosodiphenylamine, phenoxyazine, pt-butylcatechol, N-phenylnaphthylamine, 2,6-di-t-butyl-p-methylphenol, and Nanil, pyrogallol and the like.

In addition, in order to improve the hardness of the formed polyimide film, colloidal inorganic fine particles may be added. The inorganic fine particles include silica sol, titania sol, zirconia sol and the like. The amount of the colloidal inorganic fine particles used is 1 to 50% by weight based on the polyamic acid, preferably 2 to 30% by weight. When mixing all the components constituting the siloxane polyimide precursor composition or when dissolving the additive in the composition, it can be prepared as a coating solution by adding colloidal inorganic fine particles and the like.

The present invention will be further illustrated by the following examples, which are only described for the purpose of illustrating the present invention and are not intended to limit the protection scope of the present invention.

Example

Example 1

147.1 g (0.5 mole) of 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride, 95 g (0.475 mole) of oxydianiline, 6.2 g (0.025) of bis-3- (aminopropyl) tetramethylsiloxane Mole) and 1200 g of N-methyl-2-pyrrolidone were placed in a polymerization tank and stirred at 60 ° C. for 5 hours under a nitrogen stream to obtain a polyamic acid solution as a polymer having a viscosity of 13,000 centipoise at room temperature. 20 g of the polyamic acid prepared above was added with 3.2 g of dimethylaminoethyl methacrylate and 3 g of a cyclic methacrylate component as a ring-opening polymerization type cyclic monomer component as a compound having an additional type carbon-carbon unsaturated group. 0.01 g of -di- (p-azidobenzal) -4-methylcyclohexanone and 0.05 g of sensitizer 1-phenyl-1,2-butadione-2- (o-methoxycarbonyl) oxime The mixture was stirred for 30 minutes to obtain a siloxane polyimide precursor composition having a viscosity of 12,500 centipoise. The viscosity was measured using a Brookfield Viscometer No. 40 spindle. The obtained siloxane polyimide composition was coated on a silicon wafer for 30 seconds at a rotational speed of 2,300 rpm and then cured at 95 ° C. for 4 minutes to form a film of polyimide precursor having a coating having a thickness of 18 μm. When the photomask was covered and developed with an N-methylpyrrolidone solution after ultraviolet irradiation, the 8 µm pattern of the photomask showed a resolution having a deviation range within ± 0.2 µm even on the wafer. Then, after curing at 200 ° C. for 30 minutes and 350 ° C. for 30 minutes in a nitrogen gas atmosphere, the film thickness of the polyimide was 10 μm, thereby forming a very thick coating film. The adhesion characteristics of the polyimide were evaluated by scotch tape after preliminary storage of the polyimide film on the wafer for 100 hours under PCT (Pressure Cooking Test). The heat resistance of the obtained polyimide film was evaluated under a nitrogen atmosphere using TGA, and showed a very good heat resistance property with a 5% weight reduction temperature of 515 ° C. The mechanical strength of the film was measured by Instron, and good values of tensile strength of 130 MPa and elongation of 50% or more were obtained.

Comparative Example 1

The same procedure as in the above example was carried out except that the ring-opening acrylic component was not added. The photosensitive pattern on the wafer formed by the above method showed a photosensitive pattern having a deviation of -0.2 μm or more on the basis of the 8 μm pattern on the photomask, indicating that the deviation range due to shrinkage at the time of photocuring was large. In addition, as the development time was longer, the degree of crack generation on the film was increased as compared with the above example, and some pattern peeling phenomenon was observed. The properties such as other mechanical strength of the polyimide after the final curing were not significantly different from those of the above examples.

The present invention minimizes volume reduction during photocuring by using a photoreactive monomer having a compound 10:90 to 90:10 ratio having a ring-opening-type cyclic monomer and a photocrosslinkable acrylic photosensitive group. It has the effect of obtaining a line width substantially the same as the mask pattern in the high resolution region.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (4)

Tetracarboxylic dianhydride of the formula (1) to an organic solvent; Aromatic diamines of Formula 2; And Photoreactive monomer which has a compound 10: 90-90: 10 ratio which has a ring-opening-type cyclic monomer and a photocrosslinkable acrylic photosensitive group; A low shrinkage photosensitive polyimide precursor composition produced by reacting: Formula 1 Formula 2 H ₂ NR ₂ -NH ₂ Wherein R ₂ is an aromatic or aliphatic cyclic group, X is a photosensitive compound having a saturated aliphatic or unsaturated aliphatic group. The siloxane polyimide precursor composition according to claim 1, wherein a part of the tetracarboxylic dianhydride is converted into a compound represented by the following Chemical Formula 3 by pretreating the aromatic tetracarboxylic dianhydride of Formula 1 to the organic solvent. : Formula 3 Wherein R ₁ is an aromatic or aliphatic cyclic group, X is a photosensitive compound having a saturated aliphatic or unsaturated aliphatic group. The method of claim 2, wherein the alcohol is methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol and allyl alcohol (allyl alcohol), 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate from the group consisting of A siloxane polyimide precursor composition, characterized in that it is selected. According to claim 1, wherein the ring-opening polymerization type cyclic monomer is selected from the group consisting of a vinyl cyclopropane component of formula 4a, a cyclic ketene acetal component of formula 4b, and a cyclic acrylate component of formula 4c and formula 4d A low shrinkage photosensitive polyimide precursor composition, characterized in that: Formula 4a Formula 4b Formula 4c Formula 4d Wherein X and Y are halogen compounds, R 'is an aliphatic group compound, and Z is H or CH ₃ .