CN100390186C - Organic iridium compound, method for producing the compound and method for producing film - Google Patents

Abstract

An organometallic iridium compound having low melting point, excellent vaporization characteristic and low film formation temperature on a substrate, a process for producing the compound, and a process for preparing iridium-containing films using the organometallic compound are provided. The organometallic iridium compound represented by the formula (1) (example of specific compound: (ethylcyclopentadienyl)bis(ethylene)iridium) is obtained by reacting a compound represented by the formula (4) with a compound represented by the formula (2) or (3) An iridium-containing film is prepared using the compound as a precursor. In the formulae, R 1 represents hydrogen atom or a lower alkyl group; R 2 represents a lower alkyl group; X represents a halogen atom; and M represents an alkali metal.

Description

Iridium organ metallic compound prepares its method, and the method for preparing film

Technical field

The present invention relates to and to relate to the method for preparing this compound, and to relate to the method for preparing the iridium base film as the organometallic compound of the parent of preparation iridium base film on substrate.

Background technology

In recent years, in unicircuit, thirst for the ferroelectric memory of the ferroelectric residual polarization effect of research and utilization.Specifically, lead zirconate titanate (PZT:Pb (Ti, Zr) O have been studied ₃), bismuth tantalate strontium (SBT:SrBi ₂Ta ₂O ₉) and the like material.As these ferroelectric electrode materialss, noble metal films such as ruthenium, platinum, iridium, or the sull of these precious metals becomes and is sought after.Consider especially in the future iridium or iridium oxide major portion as electrode materials.Method as producing iridium and iridium oxide film has adopted sputtering method and chemical vapor deposition processes (CVD method).Specifically, based on the following reasons, the CVD method is in the main flow of the method that in the future will be considered to produce membrane electrode.The CVD method is easy to produce uniform film and has excellent step coverage (step covarage), so this method can be to be suitable for to the highly dense generation of recent circuit and electronic unit.

As adopting this CVD method to come film forming parent, it is believed that among metallic compound, to have low melting point and the organometallic compound that is easy to process is fit to.Studied so far and three (two pivalyl methane) have been closed iridium, three (methyl ethyl diketone root) closes iridium, the organometallic compound that conducts such as iridium are used for deposit iridium or iridium oxide film is closed in (cyclopentadienyl) (1, the 5-cyclooctadiene).These iridic compounds have high stability and are nontoxic in atmosphere, therefore be suitable for use as the CVD parent.But these iridic compounds are solid at normal temperatures, but also have parent gasification and transfer to the problem of substrate difficulty.

In recent years, thirst for research and have low-melting iridium complex.Have the method for low melting point iridium complex as preparation, a kind of method is that at least one hydrogen atom that will close at cyclopentadienyl (1, the 5-cyclooctadiene) on the cyclopentadienyl rings of iridium replaces with alkyl.

For example,, disclose (1, the 5-cyclooctadiene) (ethyl-cyclopentadienyl) as cyclopentadienyl derivative and closed iridium (for example JP-A-11-292888).Because this metallic compound is liquid at normal temperatures, and to close that iridium compares be low its fusing point and (cyclopentadienyl) (1, the 5-cyclooctadiene), so it is considered to have the compound of the necessary characteristic of parent institute that is used for the CVD method.But this compound has high stability, and the decomposition temperature of this complex compound is high.Therefore, the substrate temperature that when film forms, must raise.Consequently meet with such problem: step coverage is low when film forms.Also meet with such problem: the formation of iridium oxide film is difficult.At the same time, about having report as the iridium complex of the ethene of ligand and cyclopentadienyl, the synthetic method that wherein has synthetic (cyclopentadienyl) two (ethene) to close iridium (is for example seen M.Dziallas, A.Hohn and H.Werner, J.Organomet.Chem, 330 (1987) 207-219).Yet this compound at room temperature is a solid, and is uncomfortable as the CVD parent.

Of the present invention open

Considering to have made the present invention after the above-mentioned technical problem.That is to say, the present invention relates to can be used as the organometallic compound of the parent for preparing the iridium base film, the purpose of this invention is to provide have low melting point, the organometallic compound of excellent evaporation characteristic and the low film formation temperature on substrate, prepare its method, and adopt this organometallic compound to prepare the method for iridium base film.

Inventor of the present invention has done extensive and deep research to address the above problem.The result, close in the ethene of iridium by low alkyl group being incorporated into cyclopentadienyl rings (being called " Cp ring " later on) or (cyclopentadienyl) two (ethene), developed a kind of iridium complex of novelty, it has at room temperature is the fusing point of liquid, good evaporation characteristic and resolution characteristic.

The invention provides the iridium organ metallic compound of a kind of following general formula (1) representative:

R in the formula ₁Represent hydrogen atom or low alkyl group; And R ₂Represent low alkyl group.

The present invention also provides the method for the iridium organ metallic compound of a kind of preparation general formula (1) representative, comprises the compound with following general formula (4) representative:

R in the formula ₂Represent low alkyl group, and M represents basic metal, reacts with the compound of following general formula (2) representative or the compound of general formula (3) representative:

R in the formula ₁With defined above identical, and X represents halogen atom,

R in the formula ₁With X with defined above identical.

The present invention also provides the method for preparing the iridium base film again, and it comprises that the iridium organ metallic compound that uses general formula (1) representative is as parent.

Brief description of drawings

Fig. 1 is the GC/MS graphic representation of the iridic compound that obtains among the embodiment 1 of expression.

Fig. 2 is the resolution characteristic figure of the iridic compound that obtains among the embodiment 1 of expression.

Fig. 3 is that (1, the 5-cyclooctadiene) (the ethyl cyclopentadienyl) that must get among the expression comparative example 1 closes the resolution characteristic figure of iridium.

Fig. 4 represents that (methyl cyclopentadienyl) two (ethene) that obtain among the embodiment 2 close the GC/MS graphic representation of iridium.

Fig. 5 is the equipment synoptic diagram that is used for the CVD method of embodiment 3.

In the accompanying drawings:

1. the container of parent

2. oil bath

3. reaction chamber

4. substrate

5. oxidizing gas

6. counter gas

7. carrier gas

8. mass flow controller

9. mass flow controller

10. mass flow controller

11. vacuum pump

12. waste gas

Implement best mode of the present invention

Details are as follows in the present invention.

The term definition and the object lesson thereof that are used for this specification sheets will be described below.

Terminology used here " low alkyl group " refers to contain straight chain, branching or the cyclic alkyl of 1-6 carbon atom.Therefore, at R ₁And R ₂The example of the middle low alkyl group that adopts comprises methyl, ethyl, n-propyl, sec.-propyl, normal-butyl, isobutyl-, sec-butyl, the tertiary butyl, amyl group, isopentyl, neo-pentyl, tert-pentyl, the 1-methyl butyl, the 2-methyl butyl, 1, the 2-dimethyl propyl, hexyl, isohexyl, the 1-methyl amyl, the 2-methyl amyl, the 3-methyl amyl, 1, the 1-dimethylbutyl, 2, the 2-dimethylbutyl, 1, the 3-dimethylbutyl, 2, the 3-dimethylbutyl, 3, the 3-dimethylbutyl, the 1-ethyl-butyl, the 2-ethyl-butyl, 1,1,2-trimethylammonium propyl group, 1,2,2-trimethylammonium propyl group, 1-ethyl-1-methyl-propyl, 1-ethyl-2-methyl-propyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, the cyclopropyl methyl, 1-cyclopropyl ethyl, 2-cyclopropyl ethyl and cyclobutylmethyl.

In the present invention, R ₁Represent hydrogen atom or low alkyl group.R ₁Preferably methyl or hydrogen atom are more preferably hydrogen atom.On the other hand, in the present invention, R ₂Represent low alkyl group.This low alkyl group is methyl, ethyl, propyl group or butyl preferably, is more preferably methyl or ethyl.In the present invention, X represents halogen atom.The example of halogen atom comprises fluorine, chlorine, bromine and iodine.In the middle of them, chlorine and bromine are preferred.In the present invention, M represents basic metal.Alkali-metal example comprises lithium, sodium and potassium.In the middle of them, lithium and sodium are preferred.

The iridium organ metallic compound of general formula of the present invention (1) representative can be by making general formula (4) representative compound and the compound of general formula (2) representative or the compound reaction of general formula (3) representative make.Reaction conditions is not particularly limited in this reaction.For example, these two kinds of compounds can add among the suitable solvent respectively for every kind, and each solution can be mixed, and reaction at low temperatures, and aftertreatment is not particularly limited.Usually the method that adopts is: after reaction finishes mixing solutions is concentrated; For example pentane, hexane or ether extract needed compound from the gained mixture with organic solvent; Select suitable carriers; The fluid of will coming together is carried out the column chromatography separation, uses suitable solvent as eluent; The collection fluid is distilled, can obtain needed iridium organ metallic compound thus.

The organic metal iridium chemical combination that uses general formula of the present invention (1) representative can prepare the iridium base film as parent.This preparation method's concrete mode is not particularly limited.For example, any in CVD method, atomic layer deposition method (ALD method) and the spin-coating method all can adopt.

By methods such as CVD methods, ALD method, when using the iridium organ metallic compound of general formula of the present invention (1) representative to prepare the situation of iridium base film, the method for parent being delivered to filming chamber is not particularly limited.For example, Bubbling method can be adopted, also the liquid injection method can be adopted.

In the present invention,, can use iridium organ metallic compound itself, perhaps it can be dissolved in the organic solvent, use with iridium organ metallic compound solution then preparing under the situation of iridium base film by CVD method or ALD method.

Under with solution situation with an organic solvent, representative examples of organic comprises alcohols (methyl alcohol for example, ethanol or Virahol), ester class (ethyl acetate for example, butylacetate or Isoamyl Acetate FCC), gylcol ether (ethylene glycol monoethyl ether for example, ethylene glycol monomethyl ether or ethylene glycol monobutyl ether), ethers (ether for example, glyme, diglyme, triglyme or tetrahydrofuran (THF)), ketone (propyl acetone for example, hexone, ethyl butyl ketone,3-heptanone, 4-Heptanone, valerone, methyl amyl ketone or pimelinketone), and hydro carbons (hexane for example, hexanaphthene, ethylcyclohexane, heptane, octane, benzene, toluene or dimethylbenzene).But the present invention is not subject to these solvents.

Embodiment

With reference to following embodiment the present invention is made more detailed description, but should be understood that the present invention should not be considered to be subject to these embodiment.

Embodiment 1

(ethyl cyclopentadienyl) two (ethene) close the synthetic and thermal decomposition characteristic of iridium

49mg four (ethene) is closed two μ-chlorination two iridium (I) add among the 10ml THF, reaction flask is cooled to-78 ℃, add the THF solution 10ml of 17mg ethyl cyclopentadienyl lithium (lithium ethylcyclopentadienide) then.The gained mixture was stirred 30 minutes at-78 ℃, then temperature is progressively risen to room temperature, and the mixture that obtains was reacted 1 hour again, concentrate subsequently, get the muddy mixture, with this muddy mixture of hexane extraction, and use aluminum oxide that this extraction solution is carried out column chromatography (eluent: hexane), obtain 14mg needed (ethyl cyclopentadienyl) two (ethene) and close iridium.

Faint yellow oily material.

¹H-NMR (500MHz, benzene-d6, δ ppm):

4.78-4.77(m，2H)，4.66-4.65(m，2H)，2.60-2.58(m，4H)，1.90(q，J＝2，5Hz，2H)，0.94(t，J＝2.5Hz，3H)，0.94-0.91(m，4H)

IR (pure, cm ^-1):

3040，2970，2920，2870，1480，1460，1435，1310，1165，1150，1035，1010，990，810，790

MS(GC/MS，EI)：

With ¹⁹³(ethyl cyclopentadienyl) two (ethene) that Ir represents close the molecular ion peak of iridium: m/z342 (Fig. 1)

The resolution characteristic of this compound that records the results are shown in Fig. 2.As can be seen from Figure 2, the kick off temperature of iridium organ metallic compound of the present invention is near 220 ℃, so it can decompose under than the low temperature of comparative example 1 compound of describing later that obtains (common compound).

Measuring condition is as follows.

Measuring method: power-compensation differential scanning calorimetry (DSC)

Measuring condition:

Reference substance: aluminum oxide

Rare gas element: nitrogen, 50ml/ minute

Heat up: 10 ℃/minute

The comparative example

The thermal decomposition characteristic of iridium is closed in (ethyl cyclopentadienyl) (1, the 5-cyclooctadiene)

Measure the resolution characteristic that iridium is closed in (ethyl cyclopentadienyl) (1, the 5-cyclooctadiene) in the mode identical with embodiment 1, gained the results are shown in Fig. 3.As can be seen from Figure 3, the kick off temperature of this common product is near 370 ℃

Embodiment 2

(methyl cyclopentadienyl) two (ethene) close the synthetic of iridium

0.97g four (ethene) is closed two μ-chlorination two iridium (I) add among the 50ml THF, again reaction flask is cooled to-78 ℃, add the THF solution 50ml of 178mg methyl cyclopentadienyl lithium (lithiummethylcyclopentadienide) then.Gained solution was stirred 1 hour 40 minutes at-78 ℃, then temperature is progressively risen to room temperature, and the mixture that obtains was reacted 1 hour again, concentrate subsequently, get the muddy mixture, with this muddy mixture of hexane extraction, and use aluminum oxide that this extraction solution is carried out column chromatography (eluent: hexane), obtain 409mg needed (methyl cyclopentadienyl) two (ethene) and close iridium.

Off-white solid

¹H-NMR (500MHz, benzene-d6, δ ppm):

4.84(t，J＝2.0Hz，2H)，4.59(t，J＝2.0Hz，2H)，2.55-2.44(m，4H)，1.51(s，3H)，0.95-0.93(m，4H)

MS(GC/MS，EI)：

With ¹⁹³(methyl cyclopentadienyl) that Ir represents two (ethene) closes the molecular ion peak of iridium: m/z328 (Fig. 4)

Embodiment 3

Close iridium with (ethyl cyclopentadienyl) two (ethene) and prepare iridium film

Use equipment shown in Figure 5, and adopt silicon substrate, and this silicon substrate has formed the thick SiO of 100nm on its surface as substrate 4 ₂Film.Add about 10g (ethyl cyclopentadienyl) two (ethene) in the parent container and close iridium, and this container is heated, make it to be in 50 ℃ of temperature constant states with oil bath 2.Use vacuum pump 11 and pressure controlled valve, reaction chamber 3 is transferred to 10 holders, and parent container 1 is transferred to 100 holders.As carrier gas 7, and make its flow set at 100sccm with nitrogen with mass flow controller 10.With oxygen as oxidizing gas 5, and with nitrogen as counter gas 6.With mass flow controller 8 with the flow set of oxidizing gas 10sccm and with mass flow controller 9 with the flow set of counter gas at 90sccm.Substrate 4 is arranged on 400 ℃, and carries out film generation 60 minutes, and keep the state of being heated simultaneously at it.The film that forms is the metal iridium film, and this film thickness is 300nm.

Though at length and with reference to specific embodiments the present invention has been made detailed description, for those skilled in the art, it is evident that under the situation that does not deviate from spirit of the present invention and scope, can carry out various improvement and change.

The application is based on the Japanese patent application NO.2003-295329 of application on August 19th, 2003, the NO.2003-383169 of application on November 12nd, 2003, and the NO.2004-5503 of application on January 13rd, 2004, their disclosure integrally is cited as a reference.

Industrial usability

Iridium organ metallic compound of the present invention is in the side that uses the CVD method as preparation iridium base film Under the gas sparging condition, be liquid in the situation of method, so they can be supplied quantitatively. In addition, This iridium organ metallic compound can thermal decomposition under than the low temperature of common material. As a result, can be at lining Form the iridium base film with excellent step spreadability at the end. The present invention may prepare the iridium base film in a large number.

Claims (6)

1. the iridium organ metallic compound of following general formula (1) representative:

R in the formula ₁Represent hydrogen atom or contain straight chain, branching or the cyclic alkyl of 1-6 carbon atom; And R ₂Representative contains straight chain, branching or the cyclic alkyl of 1-6 carbon atom.

2. the compound claimed, wherein R according to claim 1 ₁It is hydrogen atom.

3. preparation comprises the compound with following general formula (4) representative according to the method for claim 1 or 2 claimed iridium organ metallic compounds:

R in the formula ₂Representative contains straight chain, branching or the cyclic alkyl of 1-6 carbon atom, and M represents basic metal, reacts with the compound of following general formula (2) representative or the compound of general formula (3) representative:

R in the formula ₁Represents hydrogen atom or contain straight chain, branching or the cyclic alkyl of 1-6 carbon atom, and X represents halogen atom,

R in the formula ₁With X with defined above identical.

4. the method claimed, wherein R according to claim 3 ₁It is hydrogen atom.

5. the method for preparing the iridium base film, comprise use according to claim 1 or 2 claimed iridium organ metallic compounds as parent.

6. the method claimed, wherein R according to claim 5 ₁It is hydrogen atom.

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