KR101769716B1 - Electrochemical migration preventive additives and method for inhibiting electrochemical migration by using the same - Google Patents

Abstract

According to one embodiment of the present invention, an electrochemical migration preventing additive delays or prevents growth or generation of dendrite generated between metal wiring to restrain electrochemical migration. Therefore, the present invention can ultimately prevent a short-circuit of a circuit. Moreover, reliability of a semiconductor device can be increased when the additive is mixed with an EMC or an underfill material of a packaging process such as a semiconductor to be used.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrochemical migration preventive additive and a method for preventing electrochemical migration using the electrochemical migration preventive additive.

The present invention relates to a preventive additive for inhibiting electrochemical migration causing electrical shorting and a method of using the same.

As the industrial society develops, high performance and high reliability electronic components are required, and their application fields are greatly expanded. Therefore, electronic components such as semiconductors are becoming higher in density and higher in integration. As a result, the line widths and spacing of the metal wiring and the bonding layer used for such electronic components are reduced, and new reliability problems have arisen. Wiring of electronic components generally uses copper with good electrical conductivity and thermal conductivity and low cost. However, when the wiring of the electronic component is exposed to moisture and electric current flows between the two wiring, ECM (Electrochemical migration) occurs on the circuit, which causes an electrical short in the electronic circuit, shortening the lifetime of the electronic component .

The reaction mechanism of this ECM can be distinguished by the following three steps.

Step 1: Anodic reaction (metal dissolution)

M (Metal) ^{- >} M ^{n +} + ne ^-

H ₂ O → (1/2) O ₂ + 2H ⁺ + 2e ^-

M + H ₂ O ^- & gt ^; MO + 2H ⁺ + 2e ^-

Step 2: Cathode reaction (metal or metal oxide precipitation)

M ^{n +} + ne ^- > M

O ₂ + 2H ₂ O + 4e ^- ? 4OH ^-

2H ₂ O + 2e ^- ? H ₂ + 2OH ^-

Step 3: Inter-electrode reaction (metal ion transfer & metal oxide precipitation)

2M ⁺ + 2OH ^- > M ₂ O + H ₂ O

In the ECM, the anode metal is electrochemically ionized, and the ionized metal ion is reduced at the cathode due to the potential difference between the anode and the cathode, and is precipitated into the metal. As this reaction continues, the precipitated metal generates a dendrite that grows from the cathode to the anode, causing electrical shorting. The occurrence and growth rate of ECM depends on environmental factors such as humidity, temperature, electrode spacing, and so on. There is a method of applying a polymer-based material between adjacent metal wiring layers in order to prevent ECM, but this leads to time and money loss by carrying out additional processes in conventional metal wiring fabrication and packaging. Therefore, it is necessary to carry out a study to prevent ECM easily without requiring an additional process.

An object of the present invention is to provide a preventive additive which can prevent ECM which is likely to occur in metal wiring and a method using the same.

The preventive additive for electrochemical migration, which is an embodiment of the present invention, may be selected from the group consisting of polyethyleneglycol (PEG), imidazole, benzotriazole (BTA), poly-diallyldimethylammonium chloride diallyldimethylammonium chloride (PolyDADMAC), thiourea, didecyl-dimethylammonium chloride (DDAC), diazine black (DB), 1-butyl- (1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM] HSO ₄ ), Nitrotetrazolium blue chloride (NTBC), 6-aminobenzo -thiazole, N-butyl-methylpiperidinium bromide (PP ₁₄ Br), polyethyleneimine (PEI), 4-amino-2,1,3-benzothiadi (4-amino-2,1,3-benzothiadiazole), denatomium benzoate (D enatonium benzoate, a branched quaternary ammonium surfactant, 4-nitrophenol, diallylmethylamine hydrochloride and sulfur dioxide copolymer, di An allylamine hydrochloride maleic acid copolymer (410C), an epichlorohydrin diallylamine hydrochloride quaternary amine copolymer (880), methyl diallylamine hydrolyzate Wherein at least one of methyldiallylamine hydrochloride sulfur dioxide copolymer (220 lCl), dodecyltrimethylammonium bromide (DTAB), pyridine, and gelatin is contained, and the dendritic definition Generation and Growth Also it may delay one.

The prevention additive is a chloride ion (Cl ^-) it may further comprise a.

The preventive additive may comprise polyethylene glycol and further chloride ions.

The preventive additive may comprise imidazole and further chloride ions.

The preventive additive may comprise benzotriazole and further chloride ions.

The preventive additive may comprise polyethylene glycol, imidazole and further chloride ions.

A method for preventing electrochemical migration, which is another embodiment of the present invention, is a method for preventing electrochemical migration, which comprises the steps of: (1) mixing a mixture of polyethylene glycol (PEG), imidazole, benzotriazole (BTA), poly-diallyldimethylammonium chloride Di-tert-butyldimethylammonium chloride (PolyDADMAC), Thiourea, Didecyl-dimethylammonium chloride (DDAC), Diazine black (DB) Methylimidazolium hydrogen sulfate ([BMIM] HSO ₄ ), Nitrotetrazolium blue chloride (NTBC), 6-aminobenzo-thiazole (6 aminobenzo-thiazole, N-butyl-methylpiperidinium bromide (PP ₁₄ Br), polyethyleneimine (PEI), 4-amino- 4-Amino-2,1,3-benzothiadiazole, Denatonium Benzoate (Dena tonium benzoate, a branched quaternary ammonium surfactant, 4-nitrophenol, diallylmethylamine hydrochloride and sulfur dioxide copolymer, di An allylamine hydrochloride maleic acid copolymer (410C), an epichlorohydrin diallylamine hydrochloride quaternary amine copolymer (880), methyl diallylamine hydrolyzate An electrochemical anti-migration additive comprising at least one of methyldiallylamine hydrochloride sulfur dioxide copolymer (220 lCl), dodecyltrimethylammonium bromide (DTAB), pyridine, and gelatin, Get ready A step; And mixing the prepared preventive additive with an epoxy molding compound (EMC) or an underfill material to mold the metal wiring.

Thereby delaying at least one of dendrite generation and growth between the metal wirings.

The prevention additive is a chloride ion (Cl ^-) it may further comprise a.

The preventive additive may comprise polyethylene glycol and further chloride ions.

The preventive additive may comprise imidazole and further chloride ions.

The preventive additive may comprise benzotriazole and further chloride ions.

The preventive additive may comprise polyethylene glycol, imidazole and further chloride ions.

Through the present invention, electrochemical migration can be suppressed by delaying or preventing the generation or growth of the dendritic definition occurring between metal wirings. Through this, it is possible to ultimately prevent a short circuit. In addition, when such a preventive additive is mixed with EMC or an underfill material in a packaging process such as a semiconductor, the reliability of the semiconductor device can be increased.

Figure 1 is a schematic and corrosion type image of a semiconductor bond.
2 is a schematic and corrosion type image of a semiconductor package (Flip chip).
3 is a schematic diagram of a general corrosion mechanism occurring between electrodes.
Figure 4 is a schematic diagram showing dendritic growth and inhibition.
5 is a graph showing an average and a standard error of the ECM time of Experimental Example 1. FIG.
6 is a graph showing the dendrite definition length for ECM time in Experimental Example 1. Fig.
7 is a graph showing an average and a standard error of the ECM time of Experimental Example 2. FIG.
8 is a graph showing the dendrite definition length for the ECM time in Experimental Example 2. Fig.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term "comprises" or "having" is intended to designate the presence of stated features, elements, etc., and not one or more other features, It does not mean that there is none.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

As described above, in particular, in the semiconductor package process, when electricity flows between two wirings, an electrochemical migration occurs on the circuit, which causes an electrical short in the electronic circuit, . Figure 1 shows the schematic and corrosion type of a semiconductor bond. As shown in Fig. 1, electrochemical migration occurs, and a short circuit of the lead frame tends to occur. FIG. 2 shows a schematic diagram and a corrosion type of a semiconductor package (flip chip). As shown in Fig. 2, the distance between electrodes is finer, electrochemical migration occurs between bumps, and a short circuit phenomenon is likely to occur as well. The general corrosion mechanism is shown in FIG. As shown in FIG. 3, when moisture is absorbed between the electrodes, dissolution occurs in one of the electrodes, and ions of the electrode metal dissociate. These metal ions are deposited on the other electrode. After deposition, dendrite is generated through growth and short circuit occurs.

The present inventors have found that when additives such as EMC (Epoxy Mold Compound) or underfill material, which is a packaging material existing between conductors, which is one embodiment of the present invention, are used, even if moisture is absorbed, And a deprovision is generated, so that a short circuit phenomenon can be delayed or suppressed. Thus, a technique for preventing electrochemical migration of the present invention has been derived.

In addition, mass transport is limited and dendritic deposition occurs. Mass transport refers to the transfer of material between the bulk solution and the electrode surface during an electrode reaction, which is caused by diffusion, and diffusion is known to determine the rate of the reaction. It is known that the use of a leveler and a grain refiner can reduce a circuit short circuit due to the assumption of a resin.

Thus, dendritic growth occurs when the electroplating is partially diffused. That is, on a micro-rough surface, the peak portion is more deposited than the trough portion. That is, the role of the leveler and the flattening agent is very important to suppress the dendritic growth. FIG. 4 is a schematic diagram showing this. As shown in Fig. 4 (a), a resin image is gradually formed at the peak position. On the other hand, as shown in Fig. 4 (b), when a leveling agent and a leveling agent are present, the resin appearance is suppressed.

An electrochemical antig migration additive, which is an embodiment of the present invention, may be selected from the group consisting of polyethylene glycol (PEG), imidazole, benzotriazole (BTA), poly-diallyldimethylammonium chloride (DIP), di-tert-butyl-3-methylimidazole (DIP), diisobutylaluminium chloride (1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM] HSO ₄ ), Nitrotetrazolium blue chloride (NTBC), 6-aminobenzo-thiazole thiazole, N-butyl-methylpiperidinium bromide (PP ₁₄ Br), polyethyleneimine (PEI), 4-amino-2,1,3-benzothiadiazole (4-amino-2,1,3-benzothiadiazole), denatomium benzoate (Dena tonium benzoate, a branched quaternary ammonium surfactant, 4-nitrophenol, diallylmethylamine hydrochloride and sulfur dioxide copolymer, di An allylamine hydrochloride maleic acid copolymer (410C), an epichlorohydrin diallylamine hydrochloride quaternary amine copolymer (880), methyl diallylamine hydrolyzate Wherein at least one of methyldiallylamine hydrochloride sulfur dioxide copolymer (220 lCl), dodecyltrimethylammonium bromide (DTAB), pyridine, and gelatin is contained, and the dendritic definition Less production and growth It may delay one. Preferably, the preventive additive is polyethylene glycol. Preferably, the preventive additive is imidazole. Preferably, the preventive additive is benzotriazole. The preventive additive preferably comprises polyethylene glycol and imidazole.

The prevention additive is a chloride ion (Cl ^-) it may further comprise a. EMC or the underfill manufacturing process. However, when the amount of the chloride ion is small, the corrosion resistance is improved, but the process is difficult. On the other hand, in the case of a large amount, the opposite shape appears. Therefore, it is preferable that the preventive additive contains polyethylene glycol and further chloride ions. The preventive additive preferably comprises an imidazole and further a chloride ion. Preferably, the preventive additive comprises benzotriazole and further chloride ions. Preferably, the preventive additive comprises polyethylene glycol and imidazole and further chloride ions.

In the electrochemical migration prevention method according to another embodiment of the present invention, one of the above-mentioned preventive additives is prepared, and the prepared preventive additive is mixed with an epoxy molding compound (EMC) or an underfill material, Lt; / RTI > Thereby delaying at least one of dendrite generation and growth between the metal wirings.

Hereinafter, the present invention will be described in detail with reference to examples and examples.

(Experimental Example 1)

As a reference solution for confirming the effect of the present invention, a solution having a chloride ion concentration of 100 ppb was prepared by using deionized water having an electric conductivity of 15 MΩ or more and sodium chloride (NaCl) Respectively. Deionized water is generally used for water droplet testing, and a 100 ppb chloride ion solution is used as a solution to accelerate the ionization reaction of the anodic metal. In this experimental example, a polyethylene glycol (100 ppm) + a chloride ion (100 ppb) solution and an imidazole (100 ppm) + chloride ion (100 ppb) were used as a preventive additive. Each solution was sufficiently agitated and given a sufficient aging time for stabilization. As described above, the experiment of measuring the ECM Time by dropping the prepared four kinds of solutions onto the copper wiring was carried out at least five times for each solution. This experiment is a water drop test, in which water droplets are dropped on a copper wiring fabricated as a comb type in accordance with IPC-TM-650, a voltage is applied to both copper wiring, This is an evaluation method for measuring the process and time. The water droplet test is an experimental method which is useful for growing the resin under severe conditions and observing it in a short time, when compared with other test methods. Based on the report that the difference in the assumed rate of growth of 1000 times compared with that of the conventional constant temperature and humidity test, the difference in ECM time in this test result will be effective to prevent the ECM of the copper wiring used in the actual field . In this experiment, a voltage of 3 V was applied in the atmospheric state (atmospheric temperature, atmospheric humidity), and at the same time, the ECM time was measured.

FIG. 5 shows the average and standard error of the ECM time for the reference solution and the preventive additive solution. As shown in FIG. 5, it was confirmed that the time elapsed until the resin assumption was generated in the polyethylene glycol + chloride ion solution and the imidazole + chloride ion solution was longer than that in the deionized water and chloride ion solution.

FIG. 6 is a graph showing the growth length of the resin composite at predetermined intervals during the process of connecting the resin composite. In addition, this graph is a graph in which the distance between two copper interconnections when the resin interconnections are connected is calculated as 1, and the fraction is calculated. As shown in Fig. 6, it can be seen that there is a difference between the point at which the initial resin assumption is generated and the growth rate depending on the solution used in the water droplet test. Especially, it was confirmed that the addition of polyethylene glycol and imidazole, which are ECM preventive additives, prevents ECM through different mechanisms. In the case of polyethylene glycol, the time required for the formation of dendrites was the longest, which means that it plays a role in delaying the generation of the initial dendritic state. In the case of polyethylene glycol, the ether group of polyethylene glycol prevents copper ions from being reduced in the cathode by trapping copper ions eluted from the anode. When the concentration of eluted copper ion is supersaturated with respect to the concentration of polyethylene glycol, the reduction of copper ion occurs at the cathode, and the resin is expected to grow. Copper ion trapping of polyethylene glycol is considered to inhibit the formation of the initial resin phase definition. On the other hand, in the case of imidazole, it plays a role of retarding the formation time of the resin phase similar to polyethylene glycol, but it plays a role of delaying the growth of the resin phase. The resin assumption occurs when the plating process is partially controlled by diffusion, and a material having a surface roughness of micrometres causes more adsorption than the concave region of the convex region. Imidazole containing a nitrogen functional group is believed to be adsorbed on the convex region of the surface of the copper wiring to prevent reduction of the copper ion, thereby delaying the positive growth of the resinous phase.

(Experimental Example 2)

Experiments were carried out under the same experimental conditions as in Experimental Example 1. In addition to the reference solution, polyethylene glycol and imadazole, polyethylene glycol + imidazole + chloride ion and benzotriazole + chloride ion solution were tested as a preventive additive.

In FIG. 7, as in FIG. 5, the average and standard error of the ECM time for the reference solution and the preventive additive solution are shown. In FIG. 8, as in FIG. 6, the growth length of the resin assumption is measured at a predetermined time in the process of connecting the resin assumption, and is shown in a graph. As shown in FIGS. 7 and 8, the two reference solutions, the polyethylene glycol + chloride ion solution, and the imidazole + chloride ion solution were the same as those of Experimental Example 1. The average ECM time of the polyethylene glycol + imidazole + chloride ion solution was the longest, and the time required to produce the resin solution was longer than that of the polyethylene glycol + chloride ion solution. It was also judged to play a role in delaying the growth rate of some resinous crystals like imidazole + chloride ion solution. In the case of the benzotriazole + chloride ion solution, the time required for the formation of the resin phase was longer than that of the imidazole + chloride ion solution, but shorter than that of the polyethylene glycol + chloride ion solution. It was also judged to play a role in delaying the growth rate of some resinous crystals like imidazole + chloride ion solution.

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Claims (13)

Polyimides such as polyethylene glycol (PEG), imidazole, benzotriazole (BTA), poly-diallyldimethylammonium chloride (PolyDADMAC), thiourea, Dimethyl-3-aminomethyl chloride (DDAC), diazine black (DB), 1-butyl-3-methylimidazolium hydrogensulfite, methylimidazolium hydrogen sulfate ([BMIM] HSO ₄ ), Nitrotetrazolium blue chloride (NTBC), 6-aminobenzo-thiazole, N-butyl-methylpyridinium bromide (N-butyl-methylpiperidinium bromide (PP ₁₄ Br)), polyethyleneimine (PEI), 4-amino-2,1,3-benzothiadiazole ), Denatonium benzoate, Branched quaternary amm (Branched quaternary ammonium < RTI ID = 0.0 > amm) onium surfactant, 4-nitrophenol, diallylmethylamine hydrochloride and sulfur dioxide copolymer, diallylamine hydrochloride maleic acid copolymer (Diallylamine hydrochloride and sulfur dioxide copolymer), diallylamine hydrochloride maleic acid copolymer 410C), epichlorohydrin diallylamine hydrochloride quaternary amine copolymer (880), methyl diallylamine hydrochloride sulfur dioxide copolymer (220 lCl) At least one of dodecyltrimethylammonium bromide (DTAB), pyridine, and gelatin,
Which suppresses the generation of dendrite definition of the copper wiring,
Electrochemical migration preventive additive of copper. delete delete delete delete delete Polyimides such as polyethylene glycol (PEG), imidazole, benzotriazole (BTA), poly-diallyldimethylammonium chloride (PolyDADMAC), thiourea, Dimethyl-3-aminomethyl chloride (DDAC), diazine black (DB), 1-butyl-3-methylimidazolium hydrogensulfite, methylimidazolium hydrogen sulfate ([BMIM] HSO ₄ ), Nitrotetrazolium blue chloride (NTBC), 6-aminobenzo-thiazole, N-butyl-methylpyridinium bromide (N-butyl-methylpiperidinium bromide (PP ₁₄ Br)), polyethyleneimine (PEI), 4-amino-2,1,3-benzothiadiazole ), Denatonium benzoate, Branched quaternary amm (Branched quaternary ammonium < RTI ID = 0.0 > amm) onium surfactant, 4-nitrophenol, diallylmethylamine hydrochloride and sulfur dioxide copolymer, diallylamine hydrochloride maleic acid copolymer (Diallylamine hydrochloride and sulfur dioxide copolymer), diallylamine hydrochloride maleic acid copolymer 410C), epichlorohydrin diallylamine hydrochloride quaternary amine copolymer (880), methyl diallylamine hydrochloride sulfur dioxide copolymer (220 lCl) Preparing an electrochemical anti-migration additive comprising at least one of dodecyltrimethylammonium bromide (DTAB), pyridine, and gelatin; And
And mixing the prepared preventive additive with an epoxy molding compound (EMC) or an underfill material to mold the copper wiring,
And the generation of resin intention between the copper wirings is suppressed,
A method for preventing electrochemical migration of copper. delete delete delete delete delete delete

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