TW202130856A - A structure containing a tin layer or a tin alloy layer - Google Patents

Abstract

The structure containing a tin layer or a tin alloy layer according to the present invention includes a substrate (10), a tin layer or a tin alloy layer (12) formed on the substrate (10), and a under barrier metal (11) formed between the substrate (10) and the tin layer or tin alloy layer (12). The under barrier metal (11) is a nickel alloy layer composed of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth. The under barrier metal (11) can sufficiently suppress the situation that the reaction between the metal and the tin in the tin layer or tin alloy layer (12) and forming an intermetallic compound (13) due to the metal diffusion of the metal in the substrate (10).

Description

Structure containing tin layer or tin alloy layer

The present invention relates to a structure containing a tin layer or a tin alloy layer, and more particularly to a structure containing a tin layer or a tin alloy layer provided as a conductive member such as an electrode, a wiring, or a bonding member of an electronic component.

In the past, tin and tin alloys have been used as bonding materials for electronic components and the like because of their low melting points and excellent ductility. In this case, tin and tin alloy are mainly applied on the substrate through ball mounting process, paste process, plating process, ink-jet process, etc. As the substrate, when copper or copper alloy-based substrates, nickel alloy-based substrates, etc. are used, or other non-metallic substrates are used, copper or nickel layers are usually applied on the substrate by plating, sputtering, etc. . For example, commonly used structures are: in flip chip bumps, etc., a nickel plating layer of several microns is provided on the copper sputtering layer of the substrate, and then tin or tin is provided on the nickel plating layer. Series alloy plating. The nickel plating layer provided on the substrate is usually called under barrier metal (under barrier metal, also referred to as UBM hereinafter). One of the purposes of forming UBM is to suppress metal diffusion between copper and tin or tin-based alloys. The formation of intermetallic compounds.

However, even if the UBM is provided with a nickel plating layer, due to the miniaturization of electronic circuits in recent years, the following problems have arisen: intermetallic compounds in the junction of the copper substrate or the copper sputtering layer on the substrate and the tin layer or tin-based alloy layer The increase in the ratio of electrical characteristics and connection reliability deteriorates. In order to solve this problem, it has been studied to reduce the generation of intermetallic compounds by providing a cobalt plating layer or a nickel-iron alloy plating layer as a UBM under the tin layer or the tin alloy layer (for example, refer to Patent Document 1 and Non-Patent Document 1, etc.). Prior art literature Patent literature

Patent Document 1: Specification of US Patent No. 9082762. Non-patent literature

Non-Patent Document 1: Ja-Kyung Koo and Jae-Ho Lee, Journal of Materials Transactions, Volume 58 (2017), No. 2, pages 148-151.

-The problem to be solved by the invention-

Certain effects can be obtained by using the UBM disclosed in Patent Document 1 and Non-Patent Document 1. However, under more severe conditions, it is difficult to sufficiently suppress the formation of intermetallic compounds in the cobalt plating layer and the nickel-iron alloy plating layer. A more novel composition of UBM.

The present invention was completed in view of the above-mentioned problems, and its object is to obtain a UBM capable of further suppressing the generation of intermetallic compounds between a metal-containing substrate and a tin layer or a tin alloy layer. -Solution to solve the problem-

In order to achieve the above object, the inventors conducted intensive studies and found that in a structure containing a tin layer or a tin alloy layer, a nickel alloy composed of nickel and at least one of tungsten, iridium, platinum, gold and bismuth is used. As the UBM, the layer can significantly inhibit the formation of intermetallic compounds, thereby completing the present invention.

Specifically, the structure containing a tin layer or a tin alloy layer according to the present invention is characterized by comprising: a substrate, a tin layer or a tin alloy layer formed on the substrate, and a structure formed on the substrate and The lower barrier metal between the tin layers or tin alloy layers, and the lower barrier metal is a nickel alloy layer composed of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth.

According to the structure containing a tin layer or a tin alloy layer according to the present invention, a lower barrier metal is formed between the base material and the tin layer or tin alloy layer, and the lower barrier metal is made of nickel, tungsten, iridium, platinum, A nickel alloy layer composed of at least one of gold and bismuth. Therefore, through the lower barrier metal, it is possible to prevent the metal from reacting with tin in the tin layer or tin alloy layer to generate intermetallic compounds due to the metal diffusion of the metal in the base material. Therefore, the structure has good electrical characteristics and connection reliability, and is suitable for electronic components and the like.

As described above, the lower barrier metal is a nickel alloy layer composed of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth. In this case, it is preferably composed of nickel-tungsten alloy, nickel-iridium alloy, and nickel- A nickel alloy layer composed of platinum alloy, nickel-gold alloy or nickel-bismuth alloy.

Furthermore, as described above, when the lower barrier metal is a nickel alloy layer composed of a nickel-tungsten alloy, a nickel-iridium alloy, a nickel-platinum alloy, a nickel-gold alloy, or a nickel-bismuth alloy, it is preferably 50% The following mass ratios contain nickel alloy layers of tungsten, iridium, platinum, gold, or bismuth.

In this way, the ability of the lower barrier metal to inhibit the formation of intermetallic compounds can be further improved. -The effect of the invention-

According to the structure containing a tin layer or a tin alloy layer according to the present invention, it is possible to sufficiently suppress the formation of intermetallic compounds due to the metal diffusion of the metal in the base material and the reaction of the metal with the tin in the tin layer or the tin alloy layer. Case. Therefore, the structure has good electrical characteristics and connection reliability, and is suitable for electronic components and the like.

Hereinafter, embodiments of the present invention will be described based on the drawings. The following description of the preferred embodiments is merely an example in nature, and is not intended to limit the present invention, the applicable method of the present invention, or the use of the present invention.

1, a structure containing a tin layer or a tin alloy layer according to an embodiment of the present invention will be described.

As shown in FIG. 1, in the structure according to the present embodiment, a lower layer barrier metal (UBM) 11 is formed on a base material 10, and a tin layer 12 is formed on the lower layer barrier metal 11. The base material 10 is not particularly limited, and for example, a metal substrate, a glass substrate, a silicon substrate, a sapphire substrate, an organic material substrate, or the like made of copper, nickel, or the like can be used. However, in addition to the metal substrate, a metal thin film made of copper, nickel, or an alloy containing copper and nickel is sometimes formed on the upper surface of the substrate by plating or sputtering, and then a metal thin film made of copper, nickel or copper is formed on the metal thin film. A protruding structure formed by an alloy containing copper and nickel. It should be noted that, among them, the metal thin film and the structure formed on the upper surface of such a substrate are collectively referred to as the substrate 10. In addition, the base material 10 is not limited to a flat substrate, and may be, for example, a rod-shaped or linear strip. The tin layer 12 is formed of a single metal tin or a tin alloy containing tin. In particular, as tin alloys, for example, tin-silver, tin-silver-copper, tin-copper, tin-bismuth, tin-indium, etc., but it is not limited to these. The tin layer 12 may be formed by, for example, a ball planting method, a solder paste method, a plating method, an inkjet method, etc., but it is not limited thereto.

In the case of forming the tin layer 12 by the electroplating method, the tin plating solution used basically contains a soluble stannous salt and an acid or its salt as a liquid base, as well as antioxidants, stabilizers, and complexes added as needed. Mixtures, surfactants, brighteners, slip agents, pH adjusters, conductive salts, preservatives and other additives. In addition, as the above-mentioned soluble stannous salt, for example, organic compounds such as methanesulfonic acid, ethanesulfonic acid, 2-propanol sulfonic acid, sulfosuccinic acid, and p-phenolsulfonic acid can be used. The stannous salt of sulfonic acid, as well as stannous fluoroborate, stannous sulfate, stannous oxide, stannous chloride, sodium stannate, potassium stannate, etc. In addition, when the tin layer 12 is made of tin alloy, for example, a plating solution containing tin salt and other metal salts such as silver or copper can be used to form a tin alloy film. After lamination, heat treatment is performed to melt to form an alloy film.

The above-mentioned antioxidants are used to prevent ^{the oxidation of Sn 2+} in the plating bath. For example, hypophosphorous acid or its salt, ascorbic acid or its salt, hydroquinone, catechol, resorcinol, phloroglucinol, Cresol sulfonic acid or its salt, phenol sulfonic acid or its salt, catechol sulfonic acid or its salt, hydroquinone sulfonic acid or its salt, hydrazine, etc.

The above stabilizers are used to stabilize the plating bath or prevent the decomposition of the plating bath. For example, sulfur-containing compounds such as cyanide compounds, thioureas, thiosulfates, sulfites, acetylcysteine, and hydroxycarboxylic acids such as citric acid can be used. Well-known stabilizers such as acids.

The above-mentioned complexing agent is used to stabilize Sn ²⁺ in the neutral region to prevent the formation of white precipitates or the decomposition of the plating bath. For example, hydroxycarboxylic acid, polycarboxylic acid, monocarboxylic acid, etc. can be used. Specifically, gluconic acid, Citric acid, glucoheptonic acid, gluconolactone, glucoheptonic acid lactone, formic acid, acetic acid, propionic acid, butyric acid, ascorbic acid, oxalic acid, malonic acid, succinic acid, glycolic acid, malic acid, tartaric acid , Diglycolic acid, or their salts, etc. In particular, gluconic acid, citric acid, glucoheptonic acid, glucoheptonic acid lactone, glucoheptonic acid lactone, or a salt thereof is preferable. Furthermore, ethylenediamine, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), iminodipropionic acid can also be used (IDP), hydroxyethylethylenediaminetriacetic acid (HEDTA), triethylenetetraminehexaacetic acid (TTHA), ethylenedioxybis(ethylamine)-N,N,N',N'-tetraacetic acid (ethylenedioxybis(ethylamine)-N,N,N',N'-tetraacetic acid), glycines, nitrilotrimethyl phosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid ( 1-hydroxyethane-1,1-diphosphonic acid), or their salts, etc.

The above-mentioned surfactant helps to improve the appearance, compactness, smoothness, adhesion, etc. of the plating film, and various conventional nonionic, anionic, amphoteric, or cationic surfactants can be used. As the said anionic surfactant, alkyl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylphenyl ether sulfate, alkylbenzene sulfonate, alkyl naphthalene sulfonate, etc. can be used. Examples of cationic surfactants include mono-trialkylamine salts, dimethyldialkylammonium salts, and trimethylalkylammonium salts. As non-ionic surfactants, it can be used in C ₁ ~C ₂₀ alkanols, phenols, naphthols, bisphenols, C ₁ ~C ₂₅ alkyl phenols, aryl alkyl phenols, C ₁ ~C ₂₅ alkanes Naphthol, C ₁ ~ C ₂₅ alkoxy phosphoric acid (salt), sorbitan ester, polyalkylene glycol, C ₁ ~ C ₂₂ aliphatic amine, etc., 2 ~ 300 moles of ethylene oxide ( EO) and/or propylene oxide (PO). As the amphoteric surfactant, carboxybetaine, sultaine, imidazoline betaine, aminocarboxylic acid, etc. can be used.

As the brightener or semi-brightener, for example, benzaldehyde, o-chlorobenzaldehyde, 2,4,6-trichlorobenzaldehyde, m-chlorobenzaldehyde, p-nitrobenzaldehyde, p-hydroxybenzaldehyde, furfural, 1-naphthaldehyde, 2-naphthaldehyde, 2-hydroxy-1-naphthaldehyde, 3-acenaphthaldehyde, benzylidene acetone, pyridylideneacetone, furfurylideneacetone, cinnamaldehyde , Anisaldehyde, salicylaldehyde, crotonaldehyde, acrolein, glutaraldehyde, metaldehyde, vanillin and other aldehydes; triazine, imidazole, indole, quinoline, 2-vinylpyridine, aniline, phenanthroline , New cuprous reagent, picolinic acid, thiourea, N-(3-hydroxybutylene)-p-sulfanilic acid, N-butylenesulfanilic acid, N-cinnamoylidene sulfanilic acid (cinnamoylidene sulfanilic acid), 2, 4-diamino-6-(2'-methylimidazolyl(1'))ethyl-1,3,5-triazine, 2,4-diamino-6-(2'-ethyl-4- Methylimidazolyl(1'))ethyl-1,3,5-triazine, 2,4-diamino-6-(2'-undecylimidazolyl(1'))ethyl-1, 3,5-triazine, phenyl salicylate; or benzothiazole, 2-methylbenzothiazole, 2-mercaptobenzothiazole, 2-aminobenzothiazole, 2-amino-6-methoxybenzene Thiazole, 2-methyl-5-chlorobenzothiazole, 2-hydroxybenzothiazole, 2-amino-6-methylbenzothiazole, 2-chlorobenzothiazole, 2,5-dimethylbenzothiazole Benzothiazoles such as thiazole and 5-hydroxy-2-methylbenzothiazole.

As the above-mentioned slip agent, repeating with the above-mentioned brightener, etc., β-naphthol, β-naphthol-6-sulfonic acid, β-naphthalene sulfonic acid, m-chlorobenzaldehyde, p-nitrobenzaldehyde, p-nitrobenzaldehyde, etc. can also be used. Hydroxybenzaldehyde, (ortho, p) methoxybenzaldehyde, vanillin, (2,4-, 2,6-)dichlorobenzaldehyde, (ortho, p)chlorobenzaldehyde, 1-naphthaldehyde, 2- Naphthaldehyde, 2(4)-hydroxy-1-naphthaldehyde, 2(4)-chloro-1-naphthaldehyde, 2(3)-thiophene formaldehyde, 2(3)-furaldehyde, 3-indole formaldehyde, water Salicaldehyde, o-phthalaldehyde, formaldehyde, acetaldehyde, metaldehyde, butyraldehyde, isobutyraldehyde, propionaldehyde, n-valeraldehyde, acrolein, crotonaldehyde, glyoxal, aldol, succinaldehyde, acetaldehyde Aldehydes, isovaleraldehyde, acrolein, glutaraldehyde, 1-benzylidene-7-heptanal, 2,4-hexadienal, cinnamaldehyde, benzylcrotonaldehyde, amine aldehyde condensate, isopropylene Acetone, isophorone, diacetyl, 3,4-hexanedione, acetone, 3-chlorobenzylidene acetone, substituted pyridylene acetone, substituted furfurylideneacetone, substituted thiophene methylene Acetone, 4-(1-naphthyl)-3-buten-2-one, 4-(2-furyl)-3-buten-2-one, 4-(2-phenylthio)-3 -Butene-2-one, curcumin, benzylidene acetone, benzylidene acetone, acetophenone, (2,4-,3,4-)dichloroacetophenone, benzylidene acetophenone Ketones, 2-cinnamylthiophene, 2-(ω-benzoyl) vinyl furan, vinyl phenyl ketone, acrylic acid, methacrylic acid, ethacrylic acid, ethyl acrylate, methyl methacrylate , Butyl methacrylate, crotonic acid, propylene-1,3-dicarboxylic acid, cinnamic acid, (ortho, m, p) toluidine, (ortho, p) aminoaniline, aniline, (ortho, p) Chloroaniline, (2,5-,3,4-)chloromethylaniline, N-monomethylaniline, 4,4'-diaminodiphenylmethane, N-phenyl-(α-, β-) Naphthylamine, methylbenzitriazole, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, 1,2,3-benzotriazine , Imidazole, 2-vinylpyridine, indole, quinoline, monoethanolamine and o-vanillin reactants, polyvinyl alcohol, catechol, hydroquinone, resorcinol, polyethyleneimine, ethylene dichloride Disodium aminetetraacetic acid, polyvinylpyrrolidone, etc. In addition, gelatin, polypeptone, N-(3-hydroxybutylene)-p-sulfanilic acid, N-butylenesulfanilic acid, N-cinnamylidenesulfanilic acid, 2,4-diamino-6- (2'-Methylimidazolyl (1')) ethyl-1,3,5-triazine, 2,4-diamino-6-(2'-ethyl-4-methylimidazolyl (1' )) ethyl-1,3,5-triazine, 2,4-diamino-6-(2'-undecylimidazolyl(1'))ethyl-1,3,5-triazine, Phenyl salicylate or benzothiazoles are also effective as slip agents. As the above-mentioned benzothiazoles, benzothiazole, 2-methylbenzothiazole, 2-mercaptobenzothiazole, 2-(methylmercapto)benzothiazole, 2-aminobenzothiazole, 2-amino- 6-Methoxybenzothiazole, 2-methyl-5-chlorobenzothiazole, 2-hydroxybenzothiazole, 2-amino-6-methylbenzothiazole, 2-chlorobenzothiazole, 2,5 -Dimethylbenzothiazole, 6-nitro-2-mercaptobenzothiazole, 5-hydroxy-2-methylbenzothiazole, 2-benzothiazole thioacetic acid, etc.

As the above-mentioned pH adjuster, various acids such as hydrochloric acid and sulfuric acid, various bases such as ammonia, potassium hydroxide, sodium hydroxide, etc. can be used. Further, monocarboxylic acids such as formic acid, acetic acid, and propionic acid, boric acids, phosphoric acids, and the like can be used. Dicarboxylic acids such as oxalic acid and succinic acid, hydroxycarboxylic acids such as lactic acid and tartaric acid, etc.

As the above-mentioned conductive salt, sodium salt, potassium salt, magnesium salt, ammonium salt, amine salt, etc. of sulfuric acid, hydrochloric acid, phosphoric acid, sulfamic acid, and sulfonic acid can be used. Agent sharing.

As the above-mentioned preservative, boric acid, 5-chloro-2-methyl-4-isothiazolin-3-one, benzalkonium chloride, phenol, phenol polyethoxylate, thymol, intercalated Hydroquinone, isopropylamine, guaiacol, etc.

The lower barrier metal 11 is provided to prevent the metal in the base 10 from reacting with the tin of the tin layer 12 due to metal diffusion of the metal contained in the base material 10 to generate the intermetallic compound 13.

The lower barrier metal 11 is a nickel alloy layer composed of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth. In this embodiment, as the nickel alloy layer, a nickel alloy layer composed of nickel, tungsten, iridium, platinum, gold, or bismuth can be cited, namely, a nickel-tungsten alloy, a nickel-iridium alloy, and a nickel-platinum alloy. , Nickel-gold alloy or nickel-bismuth alloy composed of nickel alloy layer, or made of, for example, nickel-gold-bismuth alloy, nickel-gold-platinum alloy, nickel-gold-iridium alloy, nickel-gold-tungsten alloy, nickel-platinum -Iridium alloy, nickel-platinum-tungsten alloy, nickel-platinum-bismuth alloy, nickel-iridium-tungsten alloy, nickel-iridium-bismuth alloy, nickel-tungsten-bismuth alloy and other nickel, as well as tungsten, iridium, platinum, gold and A nickel alloy layer composed of at least two kinds of bismuth. Among them, from the viewpoint of a significant effect of suppressing the formation of intermetallic compounds 13, a nickel alloy layer composed of a nickel-tungsten alloy, a nickel-iridium alloy, a nickel-platinum alloy, a nickel-gold alloy, or a nickel-bismuth alloy is more preferable .

When the lower barrier metal 11 is a nickel alloy layer composed of the above-mentioned nickel-tungsten alloy, nickel-iridium alloy, nickel-platinum alloy, nickel-gold alloy, or nickel-bismuth alloy, it is preferably 50% or less, more preferably The nickel alloy layer containing tungsten, iridium, platinum, gold, or bismuth is preferably 35% or less, particularly preferably 25% or less by mass ratio. By using such a nickel alloy layer as the lower barrier metal 11, the effect of suppressing the formation of the intermetallic compound 13 can be further improved. It should be noted that in the nickel alloy layer composed of nickel-tungsten alloy, nickel-iridium alloy, nickel-platinum alloy, nickel-gold alloy, or nickel-bismuth alloy, the quality of tungsten, iridium, platinum, gold or bismuth The ratio is preferably 1% or more, more preferably 3% or more. If the mass ratio of tungsten, iridium, platinum, gold, or bismuth is less than the above lower limit, the effect of suppressing the formation of the intermetallic compound 13 may not be sufficiently exhibited.

Furthermore, when the lower barrier metal 11 is a nickel alloy layer composed of the above-mentioned nickel and at least two of tungsten, iridium, platinum, gold, and bismuth, it is preferably 50% or less, more preferably 35% or less, particularly It is preferably a mass ratio of 25% or less, and a nickel alloy layer containing at least two of tungsten, iridium, platinum, gold, and bismuth in a mass ratio of 1% or more, more preferably 3% or more.

The lower barrier metal 11 can be formed by methods such as plating, sputtering, evaporation, ball planting, paste printing, and the like. For example, in the case of forming the lower barrier metal 11 by electroplating, a solution containing at least one of a water-soluble nickel salt and a water-soluble tungsten salt, iridium salt, platinum salt, gold salt, and bismuth salt can be used as a suitable substrate. A plating solution containing various additives such as the above-mentioned antioxidant, stabilizer, complexing agent, surfactant, brightener, slip agent, pH adjuster, conductive salt, antiseptic, etc., as necessary.

In the structure according to the present embodiment using the lower barrier metal 11 of the above composition, although the intermetallic compound 13 is formed as shown in FIG. 1, the thickness of the structure can be much smaller than that of the conventional structure.

The structure according to this embodiment can be applied to electronic components such as printed wiring boards, semiconductor integrated circuits, resistors, capacitors, filters, thermistors, crystal oscillators, switches, leads, or solar cells, but is not limited to this. [Example]

Hereinafter, examples for explaining in detail the structure containing the tin layer or the tin alloy layer according to the present invention are shown.

In this example, the structure (Examples 1 to 12) including the tin-containing layer or tin alloy layer of the UBM described in the present invention, and the tin-containing layer or tin alloy layer including the conventional UBM different from the above-mentioned UBM In the layer structure (Comparative Examples 1 to 5), the thickness of the produced intermetallic compound was measured and compared.

Specifically, in Examples 1 to 12 and Comparative Examples 1 to 5, a copper plating layer was applied as a substrate on the upper surface of a semiconductor wafer, and UBM and a tin layer or a tin alloy layer were sequentially formed on the substrate through electroplating. Electroplating adopts conventional and well-known methods. According to the type of coating film formed, in Examples 1 to 12, water-soluble nickel salt and water-soluble tungsten salt, iridium salt, platinum salt, gold salt and bismuth salt are used. A plating solution containing various additives in at least one of the solutions. In Comparative Examples 1 to 5, water-soluble nickel salts, or water-soluble nickel and iron salts, or water-soluble gold salts, or water-soluble It is a plating solution containing various additives in the bismuth salt solution. In addition, the plating conditions were 50°C, 2 A/dm ² , and the film thickness of each plating film was 3 μm.

Table 1 shows the composition of the UBM and the tin layer or tin alloy layer formed in the respective examples and comparative examples. It should be noted that the numbers in the UBM column of Table 1 indicate the mass ratio. For example, "Nickel 90 Gold 10" indicates an alloy containing 90% by mass of nickel and 10% by mass of gold.

The structures in Examples 1 to 12 and Comparative Examples 1 to 5 were heat-treated at 180° C. for 150 hours, and then the thickness of the intermetallic compound generated under the tin layer or tin alloy layer was measured. The measurement results are shown in Table 1. In addition, the thickness of the intermetallic compound in Examples 1-12 and Comparative Examples 2-5 is represented by the ratio based on the result of Comparative Example 1 (100%).

Table 1 UBM Tin layer or tin alloy layer Thickness of intermetallic compound after heat treatment at 180℃ for 150 hours (%) Example 1 Nickel 90 Gold 10 Tin-silver-copper 88.1 Example 2 Nickel 95 gold 5 Tin-silver 67.6 Example 3 Nickel 80 Bismuth 20 tin 61.2 Example 4 Nickel 95 Bismuth 5 Tin-silver 51.8 Example 5 Nickel 80 Tungsten 20 Tin-bismuth 58.6 Example 6 Nickel 90 Tungsten 10 tin 55.7 Example 7 Nickel 90 Iridium 10 Tin-copper 62.9 Example 8 Nickel 90 Platinum 10 Tin-bismuth 66.1 Example 9 Nickel 90 Gold 2 Bismuth 8 Tin-silver 68.2 Example 10 Nickel 80 Tungsten 10 Bismuth 10 Tin-silver 67.2 Example 11 Nickel 75 platinum 5 bismuth 20 tin 69.7 Example 12 Nickel 90 Tungsten 5 Gold 5 tin 68.3 Comparative example 1 nickel Tin-silver 100 Comparative example 2 Nickel 30 iron 70 Tin-silver 189.1 Comparative example 3 Nickel 42 iron 58 tin 126.8 Comparative example 4 gold tin 110.5 Comparative example 5 bismuth Tin-silver 120.8

As shown in Table 1, compared to the case where a nickel layer is used as the UBM and a tin-silver alloy layer is formed thereon as in the conventional UBM (Comparative Example 1), when a nickel-iron alloy layer is used as the UBM, no matter what Whether the tin-silver layer was formed on the UBM (Comparative Example 2) or the tin layer (Comparative Example 3), the thickness of the produced intermetallic compound was larger than that of Comparative Example 1.

In addition, even if a gold layer containing no nickel is used as the UBM to form the tin layer (Comparative Example 4), or a bismuth layer containing no nickel is used as the UBM to form the tin-silver layer (Comparative Example 5), the thickness of the intermetallic compound produced It is still larger than Comparative Example 1.

On the other hand, when a nickel alloy layer made of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth is used as the UBM (Examples 1 to 12), whether the tin layer is formed or the tin alloy layer is formed, The thickness of the produced intermetallic compound is smaller than that of Comparative Example 1. That is, it is shown that by using such a nickel alloy layer composed of nickel and at least one of tungsten, iridium, platinum, gold, and bismuth as the UBM, the formation of intermetallic compounds can be sufficiently suppressed compared with the conventional UBM. -Industrial availability-

According to the structure containing a tin layer or a tin alloy layer according to the present invention, it is possible to sufficiently suppress the formation of intermetallic compounds due to the metal diffusion of the metal in the base material and the reaction of the metal with the tin in the tin layer or the tin alloy layer. Case. Therefore, the structure of the present invention has good electrical characteristics and connection reliability, and is suitable for electronic components and the like.

10: Substrate 11: Lower barrier metal (UBM) 12: Tin layer (or tin alloy layer) 13: Intermetallic compounds

FIG. 1 is a diagram showing a structure containing a tin layer or a tin alloy layer according to an embodiment of the present invention.

without.

10: Substrate

11: Lower barrier metal (UBM)

12: Tin layer (or tin alloy layer)

13: Intermetallic compounds

Claims (3)

A structure containing a tin layer or a tin alloy layer is characterized in that the structure containing a tin layer or a tin alloy layer comprises: A substrate; A tin layer or tin alloy layer formed on the substrate; and A lower barrier metal formed between the substrate and the tin layer or tin alloy layer; Wherein, the lower barrier metal is a nickel alloy layer containing nickel and at least one of tungsten, iridium, platinum, gold, and bismuth. The structure containing a tin layer or a tin alloy layer according to claim 1, wherein the lower barrier metal comprises nickel-tungsten alloy, nickel-iridium alloy, nickel-platinum alloy, nickel-gold alloy or nickel-bismuth alloy Layer of nickel alloy. The structure containing a tin layer or a tin alloy layer according to claim 2, wherein the lower barrier metal is a nickel alloy layer containing tungsten, iridium, platinum, gold, or bismuth in a mass ratio of 50% or less.

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