US 6,359,159 B1Grant
MOCVD precursors based on organometalloid ligands
Issue Date:2002-03-19
•22 Claims
Abstract
Chemical vapor deposition processes utilize as precursors volatile metal complexes with ligands containing metalloid elements silicon, germanium, tin or lead.
Metadata
Assignee
- Research Foundation of State University of New York
Inventors
- John T. Welch
- Paul J. Toscano
- Rolf Claessen
- Andrei Kornilov
- Kulbinder Kumar Banger
Application Information
Application Number:US 09/729,115
Filing Date:2000-12-04
Priority Date:1999-05-19
Art Unit:7
Classifications
IPC:
C07F 702C07F 108C07F 110C07F 1506
Field of Search:
556 87556 1556 12556 28556465556466556 45556 57556 95556137556146556147534 15427248142758542725528
Patent Drawings
This patent does not have any drawings.
Description
RELATED APPLICATIONS
[0002] This application is a continuation-in-part of Ser. No. 09/314,311, filed on May 19, 1999, now U.S. Pat. No.6,184,409 B1 the contents of which incorporated herein by reference.
FIELD OF INVENTION
[0003] This invention relates to organometalloid compounds and metal complexes thereof, which are of use for chemical vapor deposition processes and in other chemical processes.
BACKGROUND OF THE INVENTION
[0004] As the microelectronics industry moves into ultralarge scale integration (ULSI), enhancement in performance speeds of integrated circuits will be achieved by reducing the device feature size and thereby the overall die size. As a result, density constraints will require multilevel structures with vertical interconnects. It is expected that the use of metals with lower resistivity, such as gold, silver and especially copper, will be necessary because of the submicron geometries.
[0005] Fabrication of interconnect structures includes one or more metallization steps. Metallization is commonly accomplished by physical vapor deposition (PVD) processes, including evaporating and sputtering. Chemical vapor deposition (CVD) processes have an advantage over these so-called “line of sight” processes in the fabrication of submicron vertical interconnects because conformal layers of metals are more easily produced.
[0006] In CVD, a volatile precursor, usually a complex of a metal with an organic ligand, serves as a source of the metal. The precursor is delivered to the substrate in the vapor phase and decomposed on the surface to release the metal. The precursor must exhibit sufficient thermal stability to prevent premature degradation or contamination of the substrate and at the same time facilitate easy handling. Vapor pressure, the adsorption/desorption behaviour, the chemical reaction pathways, and the decomposition temperature can directly affect the purity of the deposited metal film and the rate of thin-film formation.
[0007] CVD precursors very frequently are based on complexes of metals with β-diketonates such as 2,2,6,6-tetramethyl-3,5-heptanedione (thd) and acetylacetonate (acac) and fluorinated b-diketonates, such as 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (hfa or hfac) and 2,2-diethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (fod). Volatility of the non-fluorinated precursors is insufficient for many applications. The fluorinated analogs possess greater volatility, but also have a tendency to fragment, a consequence of fluorine migration/carbon-fluorine bond cleavage at elevated temperatures, leading to contamination of the substrate. Consequently, a need exists for precursors which retain volatility yet release the metal without degradation of the ligand and for ligands which are not labile or disposed toward fragmentation.
[0008] It is therefore an object of this invention to develop metal complexes for CVD precursors that are highly volatile and yet stable at the sublimation point and also retain desirable processing features. It is a further object to develop ligands for use in CVD precursors which can induce high volatility in a metal and can release the metal without degradation of the ligand. It is a further object to provide new synthetic routes for the synthesis of these ligands from commercially available starting materials in good yields.
SUMMARY OF THE INVENTION
[0009] It has been surprisingly discovered that certain organic compounds containing silicon, germanium, tin or lead, when complexed with a metal, can induce high volatility in the metal complex. The resulting complexes are stable at the sublimation point and retain desirable processing features. The compounds have the structure of formula I:
[0010] wherein
[0011] R1is C2or higher alkyl, substituted alkyl, haloalkyl, cycloalkyl, C7or higher aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, acyl, alkyl carboxylate, aryl carboxylate, alkenyl, alkynyl, or E2(R6)(R7)(R8);
[0012] R2is H, halogen, nitro, or haloalkyl;
[0013] E1and E2are independently Si, Ge, Sn, or Pb;
[0014] R3, R4, R5, R6, R7, and R8are independently chosen from alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, alkoxy, alkenyl, alkynyl or R4and R5,or R7and R8taken together form a divalent alkyl radical;
[0015] Y and Z are independently O, S or NR9; and
[0016] R9is alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, alkenyl, or alkynyl.
[0017] The present invention also relates to metal-ligand complexes that are highly volatile and yet stable at the sublimation point. The complexes also retain desirable processing features. The metal complexes of the present invention have the structure of formula II:
[0018] M Ln·pD (II)
[0019] wherein
[0020] M is a metal chosen from the group consisting of: Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Ti, Zr, Hf, Pr, V, Nb, Ta, Nd, Cr, Mo, W, Mn, Re, Sm, Fe, Ru, Eu, Os, Co, Rh, Ir, Gd, Ni, Pd, Pt, Tb, Cu, Ag, Au, Dy, Ho, Al, Ga, In, Tl, Er, Ge, Sn, Pb, Tm, Sb, Bi, Yb, Lu, Th, and U;
[0021] D is a neutral coordinating ligand;
[0022] n is equal to the valence of M;
[0023] p is zero or an integer from 1 to 6; and
[0024] L is a compound of formula III:
[0025] wherein
[0026] R1is alkyl, substituted alkyl, haloalkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, acyl, alkyl carboxylate, aryl carboxylate, alkenyl, alkynyl, or E2(R6)(R7)(R8);
[0027] R2is H, halogen, nitro, or haloalkyl;
[0028] E1and E2are independently Si, Ge, Sn, or Pb;
[0029] R3, R4, R5, R6, R7, and R8are independently chosen from alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, alkoxy, alkenyl, alkynyl or R4and R5, or R7and R8taken together form a divalent alkyl radical;
[0030] Y and Z are independently O, S or NR9; and
[0031] R9is alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, alkenyl, or alkynyl.
[0032] In another aspect, the present invention relates to a method of depositing a metal-containing layer on a substrate comprising vaporizing a metal-ligand complex of formula II and decomposing the metal-ligand complex in the presence of the substrate.
[0033] In yet another aspect, the present invention relates to ligands having haloalkyl-substituted metalloid substituents, particularly fluoroalkyl-substituted. In this case, R3, R4, R5,R6,R7, and R8are independently alkyl or haloalkyl, and at least one of R3,R4,R5,R6, R7, and R8is haloalkyl.
[0034] New synthetic routes for the synthesis of the ligands of formula I from commercially available starting materials in good yields have been discovered. In yet another aspect, the present invention relates to processes for preparing the ligands of formula I and metal complexes of formula II.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The present invention relates to organometalloid compounds that confer volatility on a metal when complexed therewith. Metalloids are defined herein as the elements silicon, germanium, tin and lead. Organometalloids are defined as compounds containing one or more metalloid atoms bonded to a carbon atom. The organometalloid compounds of the present invention have the structure of formula I:
[0036] wherein
[0037] R1is C2or higher alkyl, substituted alkyl, haloalkyl, haloalkyl, cycloalkyl, C7or higher aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, acyl, alkyl carboxylate, aryl carboxylate, alkenyl, alkynyl, or E2(R6)(R7)(R8);
[0038] R2is H, halogen, nitro, or haloalkyl;
[0039] E1and E2are independently Si, Ge, Sn, or Pb;
[0040] R3, R4, R5, R6, R7, and R8are independently chosen from alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, alkoxy, alkenyl, alkynyl or R4and R5, or R7and R8taken together form a divalent alkyl radical;
[0041] Y and Z are independently O, S or NR9; and
[0042] R9is alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, alkenyl, or alkynyl.
[0043] In a preferred embodiment, I is a silyl β-diketonate or a silyl β-thioketonate and R1is C2or higher alkyl, C7or higher aryl, or haloalkyl; R2is H; R3, R4, and R5are methyl; E1is Si; and Y and Z are independently O or S.
[0044] In a more preferred embodiment, R1is ethyl, isopropyl, n-propyl, isobutyl, n-butyl, t-butyl, trifluoromethyl, heptafluoropropyl, 2-propenyl or phenyl; E1is Si; and Y and Z are O or Y is S and Z is O.
[0045] In an even more preferred embodiment the compound is one of those appearing in Table 1:
| TABLE 1 | |
|---|---|
[0046] In another embodiment, R1is methyl, ethyl, isopropyl, n-propyl, isobutyl, s-butyl, n-butyl, CF3,C2F5, i-C3F7, n-C3F7, or —C(CH3)(CF3)2; R2is H; E1is Si or Ge; R3, R4, and R5are independently C6or lower alkyl; and Y and Z are O. α-Germa-β-diketones (formula I, where E1is Ge) are of particular interest.
[0047] In yet another embodiment, R3, R4, and R5are independently haloalkyl or alkyl. In this embodiment, R3, R4, R5, R6, R7, and R8are independently alkyl or haloalkyl, and at least one of R3, R4, R5, R6, R7, and R8is haloalkyl. In particular, E1is Si, or at least one of R3, R4, R5, R6, R7, and R8are independently fluoroalkyl, specifically C3or higher fluoroalkyl. The organometalloid compound may be an α-sila, β-diketonate wherein R1is alkyl, or haloalkyl; R2is H; E1is Si; X and Y are O; and R3, R4, and R5are independently alkyl or haloalkyl, and at least one of R3, R4, R5, R6, R7, and R8is haloalkyl. In particular, R1may be alkyl or haloalkyl, R3and R4methyl, and R5is (CH2)2(CF2)5CF3or (CH2)2(CF2)7CF3; in specific embodiments, R1is methyl, n-propyl, t-butyl, CF3,C2F5, or n-C3F7.
[0048] The volatile metal complexes of the present invention are useful in processes which deposit a metal on a substrate from a vapor phase, such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) and atomic layer epitaxy (ALE). They have the structure of formula II:
[0049] M Ln·pD (II)
[0050] wherein
[0051] M is a metal chosen from the group consisting of: Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Ti, Zr, Hf, Pr, V, Nb, Ta, Nd, Cr, Mo, W, Mn, Re, Sm, Fe, Ru, Eu, Os, Co, Rh, Ir, Gd, Ni, Pd, Pt, Tb, Cu, Ag, Au, Dy, Ho, Al, Ga, In, Tl, Er, Ge, Sn, Pb, Tm, Sb, Bi, Yb, Lu, Th, and U;
[0052] D is a neutral coordinating ligand;
[0053] n is equal to the valence of M;
[0054] p is zero or an integer from 1 to 6; and
[0055] L is a ligand of formula III:
[0056] wherein
[0057] R1is alkyl, substituted alkyl, haloalkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, acyl, alkyl carboxylate, aryl carboxylate, alkenyl, alkynyl, or E2(R6)(R7)(R8);
[0058] R2is H, halogen, nitro, or haloalkyl;
[0059] E1and E2are independently Si, Ge, Sn, or Pb;
[0060] R3, R4, R5, R6, R7, and R8are independently chosen from alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, alkoxy, alkenyl, alkynyl or R4and R5, or R7and R8taken together form a divalent alkyl radical;
[0061] Y and Z are independently O, S or NR9; and
[0062] R9is alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, heteroaryl, arylalkyl, alkoxy, alkenyl, or alkynyl.
[0063] Preferred metals are Cu, Co, Mn, Ag, In, Ce, Sr, Ba, Ru, or Au. More preferred metals are Cu and Ag. In some embodiments, Pd and Pt are preferred metals. Preferred ligands are the preferred organometalloid compounds described above. In particular, ligands of formula III, wherein R1is methyl, ethyl, isopropyl, n-propyl, isobutyl, s-butyl, n-butyl, CF3, C2F5, i-C3F7, n-C3F7, or —C(CH3)(CF3)2; R2is H; E1is Si or Ge; R3, R4, and R5are independently C6or lower alkyl; and Y and Z are O, may be used. α-Germa-β-diketones (formula III, where E1is Ge) may also be used.
[0064] Ligands having reduced oxygen content can reduce oxygen contamination of the substrate during metal deposition. Preferred metal complexes are listed in Table 2:
| TABLE 2 | |
|---|---|
| CU((CH | CU(CF |
| CU((CH | CU((CH |
| CU(CH | CU(CF |
| CU(CH | CU(C |
| CU(CH | CU(H |
| CU((CH | Co((CH |
| Ag((CH | Mn((CH |
[0065] The term “complex” is intended to be broadly construed to encompass compounds as well as coordination complexes wherein at least one metal atom is covalently, ionically or associatively coordinated to at least one organic ligand group. Accordingly, the metal complexes of the present invention may contain one or more neutral coordinating ligands (D in formula II) in addition to the organometalloid ligands described above, in particular when the metal has a valence of one. Suitable coordinating ligands include Lewis bases such as vinyltrimethylsilane (VTMS), bis-(trimethylsilyl) acetylene, 1,5-cyclooctadiene (COD), 1,6-dimethyl-1,5-cyclooctadiene, alkyl phosphines, alkynes, such as trimethylsilylalkyne (TMSA) and mixtures thereof.
[0066] In another embodiment, the present invention relates to metal complexes with fluorinated ligands, that is, where R3, R4, R5, R6, R7, and R8are independently chosen from alkyl and haloalkyl, and at least one of R3, R4, R5, R6, R7, and R8is haloalkyl. These complexes exhibit unexpected order in the solid state, in particular where E1is Si and at least one of R3, R4, or R5is C3or higher fluoroalkyl. This is illustrated by the crystal structure of a complex where M is copper, R3and R4are methyl and R5is (CH2)2(CF2)7CF3, as determined by x-ray diffraction. The structure is shown in FIG. 1. It can be seen from the figure that the perfluoroalkyl groups of one molecule associate with the perfluoroalkyl groups of other molecules in an orderly, interdigitated manner. The result is formation of a distinct fluorous region in the crystal.
[0067] Nanostructured materials composed of these complexes may contain separate fluorine- and /or metal-containing regions, domains, areas or layers, depending on the composition of the complex(es) employed, and method of fabricating the nanostructured materials. These regions may have oxophilic, fluorophilic, lipophilic and/or hydrophilic properties, and are, therefore, are useful in many applications. Fluoroalkyl domains are typically optically transparent and possess low k properties. Nanostructured materials having such domains may be used as nanoscale slits for microelectrooptical devices or as micromagnetic domains for data storage. Where self-organized Langmuir Blodget films are formed, the nanostructured materials may be used as magnetically sensitive thin films. In addition, the materials may be useful as organized catalysts. For example, a fluorocarbon interlayer may facilitate selective accumulation of reactants in oxidative transformations where the oxidized product might be protected from overoxidation due to limited solubility of the more polar product in the fluorous or fluorophilic phase. In particular, where the nanostructured material consists of a bimetallic catalyst created by combination of a mixture of two or more complexes, such as a mixture of a copper complex with a palladium complex, thin film catalysts for oxidative transformations may be formed.
[0068] Synthetic methods for the preparation of β-diketones are numerous and well documented. However, application of these strategies to the synthesis of silyl β-diketonates is frequently unsuccessful, due to the reactivity of the product to the reagents or reaction conditions, and to the occurrence of side reactions via the cleavage of the carbonyl-silicon bond. Therefore, it is preferred that the organometalloid compounds of the present invention be prepared by the processes of the present invention.
[0069] The organometalloid compounds may be prepared by a Claisen condensation between a lithium enolate anion and an acyl, thioacyl or imino compound having a leaving group adjacent to the unsaturated group. This reaction is illustrated in Scheme 1:
[0070] In Scheme 1, R1, R2, R3, R4, R5, R6, R7, R8, R9, E1, Y and Z are as defined for the compounds of formula I, above, R is alkyl, and Q is a leaving group. Suitable leaving groups for the process are halo, acyl, alkoxy, phenoxy, amido, dialkylamino, and alkoxyamino. Preferably, R1C(Y)Q is an acid chloride or an ester. In the synthesis of non-fluorinated silyl-β-diketones, R1C(Y)Q is preferably an acid chloride. The procedure may also be used for the synthesis of fluorinated derivatives, that is, where one or more of R1, R3, R4, or R5are fluoroalkyl groups. Yields are typically lower than with non-fluorinated derivatives, presumably because of the enhanced acidity of the fluorinated β-diketonates and the pursuant rapid protonation of the enolate. Therefore, it may be desirable to employ a variation of the process of Scheme 1, illustrated in Scheme 1a, for the preparation of fluorinated β-diketones. In this procedure, base is added to a mixture of the two starting materials. Either lithium diamine (LDA) or NaH may be utilized as bases. Even in the presence of good electrophiles, the desired β-diketones may be formed. When the perfluoroacid ester or acid fluorides were employed instead of acid chlorides at elevated temperature (−20° to −40° C.), higher yields of the fluorinated β-diketones, with almost complete consumption of the starting acylsilanes, resulted.
[0071] In another embodiment, the organometalloid compounds are prepared as illustrated in Scheme 2. A thioketal-protected acylmetalloid is reacted with an alkyllithium compound, such as n-butyl lithium, and the product is subsequently reacted with a copper salt to form a protected lithium dithianylmetalloid cuprate. The cuprate is then reacted with an appropriate α-bromoketone or α-bromo-thioketone. The thioketal protecting group can be removed by methods described in the literature. Preferably the deprotection is accomplished by treatment with a suitable mercury reagent. An example of an effective mercury reagent is a combination of mercuric oxide and mercuric chloride.
[0072] The metal complexes of the present invention may be prepared by reacting the organometalloid compounds synthesized as described above with a metal salt under protic or aprotic conditions. The ligand is dissolved in a suitable solvent and the anion of the ligand is formed by abstraction of a proton with base. The metal salt is then added, and the resulting metal ligand complex is isolated by removal of the solvent and crystallized. Under protic conditions, a protic base such as sodium hydroxide, may be used, with a protic solvent, such as an aqueous alcohol. Similarly under aprotic conditions, aprotic bases and solvents may be used. An example of a suitable aprotic solvent is tetrahydrofuran; an example of a suitable aprotic base is potassium hydride.
[0073] In another embodiment, the metal complexes may be prepared directly as shown in Scheme 3.
[0074] In Scheme 3, R1, R2, R3, R4, R5, R6, R7, R8, R9, E1, Y and Z are as defined for the compounds of formula III, above, and R is alkyl or phenyl. The starting lithium metalloid compound of formula E1R3R4R5Li is prepared according to the method described in the literature(Still, W. C., J. Org. Chem.,41, 3063-3064 (1976)). The lithiummetalloid compound is then reacted with an appropriate compound, as depicted in Scheme 3, for example, a β-diketone, a β-thioketone, or a β-ketoimine, to yield a ligand of formula III. Without isolating the product, a metal salt is added to form a complex of the metal with the ligand.
[0075] Acylgermane compounds for use in synthesis of α-germa-β-diketones may be prepared via the metallation of ethyl vinyl ether. Scheme 4 illustrates a process in which acetyl trimethylgermane is prepared from ethyl vinyl ether and chlorotrimethyl-germane. Chlorotrimethylgermane, alternately listed as trimethylgermanium chloride, is commercially available, for example, from Aldrich. α-Germa-β-diketones may be synthesized by the procedures described for the synthesis of the α-sila-β-diketones, including those illustrated in Schemes 1 and 1a, and particularly by that in Scheme 1. Similarly, metal complexes with α-germa-β-diketones may be prepared by the methods shown in Schemes 2 and 3.
[0076] Processes whereby metals are deposited from volatile precursors are utilized in many different microelectronics applications. Metals such as Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, or Ce are typically used in applications such as high k dielectrics, superconductors, and high refractive index materials, although their use is not limited to these applications. Metals such as Ti, Zr, Hf, Pr, V, Nb, Ta, Nd, Cr, Mo, W, Mn, Re, or Sm are typically used in microelectronic applications chemically combined with nitrogen or silicon as the nitride or silicide for use as barrier materials or hard coatings, although, again, their use is not limited to these applications. Metals such as Fe, Ru, Eu, Os, Co, Rh, Ir, Gd, Ni, Pd, Pt, Tb, Cu, Ag, Au, Dy, Zn, Cd, Hg, Ho, Al, Ga, In, Tl, and Er are typically used in electronics applications as metals, or metal alloys, in particular, as metal or metal alloy films for interconnects, electrodes, and mirrors, although, again, their use is not limited to these applications. Metals and metalloids such as Si, Ge, Sn, Pb, Tm, Sb, Bi, Yb, and Lu are typically used in microelectronic devices and as semiconductors, although, again, their use is not limited to these applications.
[0077] The metal complexes of the present invention may be deposited on a substrate to form a layer of one or more metals in the form of the metal or of particular inorganic compounds, for example as an oxide, a hydroxide, a carbonate, a silicide or a nitride. It will be apparent to a person skilled in the art that, if desired, he may use not only a particular compound of formula II but also mixtures of such compounds in which M, L, or both vary. A metal complex is advantageously decomposed in the vapor phase by a metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) or atomic layer epitaxy (ALE) process. The principle of these processes and suitable apparatuses for these purposes are well known in the art.
[0078] Typically, an apparatus for deposition from the vapor phase is pressure tight and can be evacuated. The substrate which is to be coated is to be introduced into this apparatus. Under reduced pressure the complex of formula II is vaporized. If desired, inert or reactive gas may be present in the apparatus in addition to the complex of the present invention in the vapor state.
[0079] The metal complex, in vapor form, is typically continuously or intermittently introduced into the apparatus via a special line. In some cases the metal complex may be introduced into the apparatus together with the substrate which is to be coated and not vaporized until it is within the apparatus. A carrier gas may optionally be used to aid in transporting the metal complex into the apparatus. The vaporization of the metal complex can be promoted by heating and if desired by the addition of the carrier gas.
[0080] Decomposition of the substrate may be effected by known methods. In general, these are thermal decomposition, plasma-or radiation-induced decomposition and/or photolytic decomposition. Thermal decomposition from the vapor phase is usually performed so that the walls of the apparatus are kept cold and the substrate is heated to a temperature at which the desired layer is deposited on the substrate. The minimum temperature required for decomposition of the compound may be determined in each case by simple testing. Usually, the temperature to which the substrate is heated is above about 80° C. The substrate may be heated in a conventional manner, for example, by resistance heating, inductive heating, or electric heating, or the substrates may be heated by radiation energy. Laser energy is particularly suitable for this. Laser heating is particularly advantageous in that lasers can be focused, and therefore can specifically heat limited areas on the substrate.
[0081] An apparatus for thermal chemical vapor deposition is typically pressure tight such as are used in high vacuum techniques as this process is typically carried out under reduced pressure. The apparatus may comprise gas lines which can be heated for carrying the metal complexes or the inner gas, blockable gas inlets and outlets, temperature measuring means if decomposition is to be induced by radiation, a radiation source must also be present. In operation, the metal complex is introduced into the apparatus in the vapor phase. An inert or reactive carrier gas may be included.
[0082] Decomposition of the metal complex may be brought about as discussed above. For example, the decomposition may be plasma induced by a D.C. plasma, high-frequency plasma, microwave plasma or glow discharge plasma. Alternately photolytic decomposition may be effected by using a laser operating at a suitable wavelength.
[0083] The thickness of the layer deposited typically depends on the length of the deposition, on the partial pressure in the gas phase, on the flow rate of the gas and on the decomposition temperature. Depending on the desired layer thickness, a person skilled in the art can readily determine the time and deposition temperature required to produce a layer of a given thickness by simple tests.
[0084] If the metal complex is decomposed under an atmosphere of an inert gas, for example, argon, metal-containing layers are typically deposited in which the metal is essentially metallic form. The decomposition may also be carried out under a reactive gas atmosphere, including a reducing atmosphere, an oxidizing atmosphere, and a hydrolyzing or carbonizing atmosphere. A reducing atmosphere with hydrogen as the reactive gas is typically used for deposition of layers containing metals, for example, copper. Where the decomposition is carried out under an oxidizing atmosphere, for example, one containing oxygen, nitrogen dioxide or ozone, layers containing the metal in the form of an oxide are formed. Alternatively, it is also possible to operate in a hydrolyzing or carbonizing atmosphere, for instance, in the presence of water and/or carbon dioxide. The metal carbonate or hydroxide which is produced as an intermediate stage may be subsequently calcined to form the metal oxide. In addition, use of ammonia as a reactive gas yields layers containing the metal in the form of a nitride.
[0085] The process according to the invention is also suitable for depositing layers which contain one or more metals. In this case, the deposition process is characterized in that for depositing layers containing more than one metal, one or more compounds of formula II or other formulas are decomposed simultaneously or successively.
EXAMPLES
Example 1
[0086] Preparation of (CH3)3CCOCH2COSi(CH3)3(IV) via Claisen Condensation of a Lithium Enolate and an Acid Chloride
[0087] A two liter 3-neck flask held at 0°-C. was equipped with a magnetic stirrer, a rubber septum and a silicon oil bubbler under a positive flow of nitrogen gas. The flask was charged with anhydrous diethyl ether (250 mL) and diisopropylamine, (11.3 mL, 86.2 mmol), 2.5 M solution of n-BuLi in hexane (34.5 mL, 86.2 mmol) was added very slowly to the stirred solution. Once addition of the n-BuLi was complete the reaction temperature was maintained at 0° C. for 1 h to ensure generation of lithium diisopropylamide, (LDA). The temperature was lowered to −85° C. and acetyltrimethylsilane (10.0 g, 86.2 mmol), was then added slowly to the mixture. A smooth exothermic reaction ensued which resulted in the formation of corresponding organolithium anion, (Me3Si(C)(OLi)CH2). A second one-liter single-neck flask held at −110° C. equipped with a magnetic stirrer, a rubber septum and under a positive flow of nitrogen gas, was charged with anhydrous diethyl ether (250 mL) and trimethylacetylchloride, (10.6 mL, 86.2 mmol). After 10 minutes the labile trimethylsilylorganolithium anion, (Me3Si(C)(OLi)CH2), was slowly transferred to the second flask via a cannula the reaction temperature was maintained between −110° C. and −75° C. After 1 hour, the reaction was essentially complete and was quenched with saturated ammonium chloride solution. Purification of the silyl β-diketonate was effected via flash column chromatography using a 100:1 (hexane: diethyl ether) eluant.
Example 2
[0088] Preparation of IV via Claisen Condensation of a Lithium Enolate and an Ester
[0089] A two liter 3-neck flask held at 0° C. equipped with a magnetic stirrer, a rubber septum and a silicon oil bubbler and under a positive flow of nitrogen gas was charged with anhydrous diethyl ether (250 mL) and diisopropylamine, (11.3 mL, 86.2 mmol). n-Butyllithium (34.4 mL, 86.2 mmol, 2.5 M in hexane) was added very slowly to the stirred solution. Once addition of the n-BuLi was complete, the reaction temperature was maintained at 0° C. for 1 hour to ensure generation of lithium diisopropylamide, (LDA). The temperature was then lowered to −85° C. and acetyltrimethylsilane (10.0 g, 86.2 mmol) was added slowly to the mixture. A smooth exothermic reaction ensued which resulted in the formation of corresponding lithium enolate, (Me3Si(C)(OLi)CH2). A second one-liter single-neck flask held at −110° C. equipped with a magnetic stirrer, a rubber septum and under a positive flow of nitrogen gas, was charged with anhydrous diethyl ether (250 mL) and methyl pivaloate, (10.6 mL, 86.2 mmol). After 10 minutes, the reactive lithium enolate, (Me3Si(C)(OLi)CH2), was slowly transferred to this mixture via a cannula while the reaction temperature was maintained between −110° C. and −75° C. After 2 hours, the reaction was essentially complete and was then quenched with saturated ammonium chloride solution. Purification of the silyl β-diketonate was effected via flash column chromatography using a 100:1 (hexane: diethyl ether) solvent system.
Example 3
[0090] Preparation of IV via Pseudo Barbier Conditions
[0091] Trimethylsilyllithium, (18 mmol) was prepared according to the literature method (Still, W. C., J. Org. Chem.,41, 3063-3064 (1976)) and then transferred via cannula to a second reaction flask held at −78° C., charged with anhydrous diethyl ether, (150 mL) and methyl 4,4-dimethyl-3-oxopentanoate, (CH3)3CCOCH2CO2CH3(2.09 g, 18 mmol), which resulted in the dissipation of the red colour. (Gasking, E. I.; Whitman, G. H. J. Chem. Soc., Perkin Trans.1, 1985, 409-414) After 30 minutes the reaction was quenched with saturated ammonium chloride, (100 mL) and copper acetate(II) monohydrate, (3.60 g, 18 mmol) was added to yield the crude silyl β-diketonate copper complex. Subsequent purification yielded pure metal complex.
Example 4
[0092] Preparation of IV by the Dithiane Route
[0093] A 3-neck flask held at −30° C. was equipped with a magnetic stirrer, a rubber septum and a silicon oil bubbler was under a positive flow of nitrogen gas. The flask was charged with anhydrous THF (30 mL) and 2-trimethylsilane-1,3-dithiane, (3.8 mL, (20 mmol). n-Butyllithium (8.0 mL, 20 mmol, 2.5 M in hexane) was added very slowly to the stirred solution. Once addition of n-BuLi was complete the reaction temperature was maintained at −30° C. for 24 hour to ensure generation of 2-lithio-1,3 dithiane. The anion was transferred via a cannula to a second flask maintained at −60° C. and charged with an ethereal solution of CuBr.Me2S (2.06 g, 10 mmol). After approximately one hour the formation of the 2-lithio-1,3-dithianylcuprate was essentially complete. Bromo pinacolone, (CH3)3CCOCH2Br, dissolved in ether, was then added slowly to the organocuprate and was allowed to react for 24 hour at −30° C. The reaction was quenched with saturated ammonium chloride solution. Vacuum distillation (125-130° C., 0.5 mm Hg) afforded the pure product.
[0094] Deprotection of the dithiane protected silyl β-diketonate was achieved by treatment with mercuric oxide and mercuric chloride in an aqueous alcoholic solution for 1.5 hours, yielding the desired the silyl β-diketonate upon filtration and concentration.
Example 5
[0095] Formation of Co((CH3)3CCOCHCOSi(CH3)3)3Under Protic Conditions
[0096] A solution of IV (0.54 g, 2.7 mmol) prepared as in Example 1 in aqueous ethanol (80 mL) was prepared. To the stirred solution, an aqueous ethanolic solution of sodium hydroxide (0.1 g, 3 mmol) was slowly added and allowed to react approximately 15 minutes. The slow addition of this solution to cobalt (II) chloride hexahydrate, (0.30 g, 1.4 mmol) dissolved in aqueous ethanol resulted in the formation of a deep green solution. The solvent was removed in vacuo to leave behind the crude cobalt (III) silyl β-diketonate complex. Addition of pentane and water, followed by subsequent work-up and sublimation resulted in isolation of the analytically pure metal complex.
Example 6
[0097] Formation of Cu((CH3)3CCOCHCOSi(CH3)3)2Under Aprotic Conditions
[0098] Under aprotic conditions, IV (0.25 g 1.3 mmol), prepared as in Example 1, was dissolved in THF (100 mL). To the stirred solution, potassium hydride, (KH), (0.05 g, 1 mmol) was added slowly and allowed to react for approximately 30 minutes. The addition of copper (II) chloride dihydrate, (0.11 g, 6.3 mmol) portionwise resulted in the formation of a deep green solution. The reaction was then quenched carefully with water and extracted with pentane. The solvent was then removed in vacuo to leave behind the copper (II) silyl β-diketonate complex, which on sublimation yielded the analytically pure metal complex.
Example 7
[0099] Formation of Cu((CH3)3CCOCHCOSi(CH3)3)2Under Protic Conditions
[0100] Under protic conditions, IV (0.25 g, 1.3 mmol), prepared as in Example 1, was dissolved in aqueous ethanol (80 mL). To the stirred solution, an aqueous ethanolic solution of sodium hydroxide (0.1 g, 3 mmol) was slowly added and allowed to react approximately 15 minutes. Copper (II) chloride dihydrate, (0.11 g, 6.3 mmol) was then added which resulted in the formation of a deep green solution. The solvent was then removed in vacuo to leave behind the copper (II) silyl β-diketonate complex. Sublimation resulted in the isolation of analytically pure metal complex.
Example 8
[0101] Direct Formation of Cu((CH3)3CCOCHCOSi(CH3)3)2Using Crude IV
[0102] To a stirred solution of crude IV (2.73 g, 13.8 mmol) dissolved in THF (100 mL), a slurry of excess copper (II) acetate hydrate, (5.46 g, 27.4 mmol) in aqueous THF was added. Upon addition, a deep green solution formed. Extraction, washing, drying, and concentration resulted in isolation of a green oil. Column chromatography on silica gel using a 100:1 hexane-ether eluant system yielded semi-pure silyl β-diketonate copper (II) complex. Controlled sublimation resulted in the formation of analytically pure metal complex.
Example 9
[0103] Direct Formation of Cu((Ch3)3CCOCHCOSi(Ch3)3)2Using Pure IV
[0104] To a stirred solution of pure IV, (5.00 g, 25 mmol) dissolved in THF (100 mL), a slurry of copper (II) acetate hydrate, (3.00 g, 15 mmol) in aqueous THF was added. Upon addition, a deep green solution formed. Extraction, washing, drying, and concentration in vacuo resulted in isolation of the copper(II) silyl β-diketonate complex. Sublimation resulted in the formation of analytically pure metal complex.
Example 10
[0105] Preparation of Cu(I)((Ch3)3CCOCHCOSi(Ch3)3).COD
[0106] Under anaerobic conditions, 1,5-cyclooctadiene (0.1 g, 1 mmol) was added dropwise to a suspension of copper (I) chloride in THF. The suspension was stirred for 10 minutes, after which a solution of the potassium salt of IV (prepared by the addition of potassium hydride (0.05 g, 1 mmol) over 30 minutes to a solution of IV (0.25 g, 1.3 mmol)), was carefully added via syringe and allowed to react for approximately 3 hours. The resultant copper(I) silyl β-diketonate complex was isolated by subsequent anhydrous work-up.
Example 11
[0107] Formation of Mn((Ch3)3CCOCHCOSi(CH3)3)3via Lewis Base
[0108] A solution of IV (0.54 g, 2.7 mmol) in aqueous ethanol (80 mL) was prepared. To the stirred solution was slowly added an aqueous ethanolic solution of sodium hydroxide (0.1 g, 3 mmol). The resultant solution was stirred for approximately 15 minutes and then slowly added to manganese (II) chloride (0.176 g, 1.4 mmol) dissolved in aqueous ethanol which resulted in the formation of a dark green solution. The solvent was removed in vacuo to leave behind the crude manganese(III) silyl β-diketonate complex. Addition of pentane and water followed by subsequent work-up and sublimation yielded an analytically pure metal complex.
Example 12
[0109] Preparation of Cu((Ch3)3CCSCHCOSi(Ch3)3)2via Claisen Condensation of Lithium Enolate and Thioacid Chloride
[0110] A two liter 3-neck flask held at 0° C. was equipped with a magnetic stirrer, a rubber septum and a silicon oil bubbler under a positive flow of nitrogen gas. The flask was charged with anhydrous diethyl ether (250 mL) and diisopropylamine (11.3 mL, 86.2 mmol). n-Butyllithium (34.5 mL of a 2.5 M solution in hexane, 86.2 mmol) was added very slowly to the stirred solution. Once the addition of BuLi was complete, the reaction temperature was held at 0° C. for 1 hour to ensure generation of lithium diisopropylamide, (LDA). The temperature was lowered to −85° C. and acetyltrimethylsilane (10.0 g, 86.2 mmol) was added slowly to the mixture. A smooth exothermic reaction ensued which resulted in the formation of corresponding organolithium enolate, (Me3Si(C)(OLi)CH2). A second one liter single-neck flask held at −110° C. and equipped with a magnetic stirrer, a rubber septum under a positive flow of nitrogen gas, was charged with anhydrous diethyl ether (250 mL) and trimethylthioacetylchloride, (10.6 mL, 86.2 mmol). After 10 minutes, the labile trimethylsilylorganolithium anion, (Me3Si(C)(OLi)CH2), was slowly transferred to the second flask via cannula while maintaining the reaction temperature between −110° C. and −75° C. After 1 hour the reaction was quenched with saturated ammonium chloride solution. Purification of the silyl β-thioketonate can be effected by flash column chromatography using a 100:1 (hexane: diethyl ether) eluant. The proton NMR spectrum of the product gave the expected results.
Example 13
[0111] Volatility of Metal Complexes with Silyl β-Diketonates and Silyl β-Thioketonates
[0112] Thermogravimetric analysis (TGA) was performed on samples of the metal complexes listed in Table 3. The samples were heated at a rate of 10° C./min under an argon atmosphere. Weight loss was associated with transformation of the complexes into the vapor phase. The TGA curves showed rapid and complete volatilization of the complexes over a narrow temperature range, indicating the absence of decomposition under the conditions employed. The inflection point of the curve is taken as the temperature at which approximately 50% of the sample by weight has volatilized. This temperature, listed as T50%in the table, is a measure of relative volatility, and is tabulated for each compound. The T50%values range from a low of about 111° C. for the fluorinated compound Cu(CF3COCHCOSi(Ch3)3)2, to a high of about 170° C. for a complex with a phenyl-substituted ligand, Cu(C6H5COCHCOSi(Ch3)3)2. The last entry in the table, for Cu(H2C=(Ch3)COCHCOSi(Ch3)3)2, showed a two-stage volatilization.
| TABLE 3 |
|---|
| Volatility of Metal Diketonate Complexes |
Example 14
[0113] Chemical Vapor Deposition of Copper
[0114] Copper films were deposited on fragments of silicon wafers, including wafers having surfaces composed of silicon, silicon dioxide, patterned silicon dioxide, and tungsten nitride, using a copper (II) silyl β-diketonate precursor of composition Cu((Ch3)3CCOCHCOSi(Ch3)3)2.
[0115] A cold wall stainless steel single wafer CVD reactor was employed for the depositions. The wafers were loaded into the chamber through a door and placed on a resistively heated stainless steel pedestal bearing a quartz plate and heated to 300° C. under a flowing hydrogen ambient atmosphere. The actual temperature of the wafer was measured via a thermocouple contacting the top side of the wafer. The system pressure was then reduced to the desired deposition pressure of 500 mTorr. The pressure was maintained throughout the time of the deposition using an automated throttle valve.
[0116] A source of the precursor was maintained at 140° C. The precursor was delivered to the reactor by means of a hydrogen carrier/reactant gas bubbler at a flow rate of 60 sccm at approximately 500 mTorr. After the deposition, the carrier gas flow was terminated, the source was closed to the reactor, and the chamber was evacuated to less than 20 mTorr and then flushed with nitrogen gas. The heater was allowed to cool under a flow of nitrogen. The test wafers were retrieved from the reactor through the door of the reactor.
[0117] The resulting copper films were smooth and exhibited high conformality at thicknesses ranging from 100 Å to 3000 Å (10 nm to 300 nm).
Example 15
Preparation of Cu(II) Complex with 2,2,6,6-Tetramethyl-2-Germa-3,5-heptanedione (Cu(tmghd)
[0118] Preparation of Acetyltrimethylgermane
[0119] The addition of one equivalent of tert-butyllithium to a THF solution of distilled ethyl vinyl ether at −110° C. resulted in a highly exothermic reaction, the internal temperature rose to −78° C. with concomitant formation of a yellow precipitate. On completion of the addition, the yellow solid dissolved when the temperature of the reaction was maintained at −25° C. After 30 minutes, metallation was essentially complete with no evidence of decomposition of the lithium reagent. The solution was then cooled to −85° C. and chlorotrimethylgermane was added slowly so that the reaction temperature did not exceed −80° C. After allowing the reaction to warm to room temperature over 4 h, the crude germylated product was isolated by quenching with saturated NaHCO3solution, extracted with pentane, dried over Na2SO4and concentrated in vacuo. 1H and 13C NMR of the clear solution was consistent with the formation of H2C=C(OEt)GeMe3. 1H NMR (CDCl3): δ4.49 (d, J=1.78 Hz 1H,=CH2),4.41 (d,J=1.78 Hz 1H,=CH2),3.68 (q,2H, —CH2),1.26 (t, 3H, CH2—CH3),0.23 (s, 9H, Ge—CH3). 13C NMR (CDCl3): δ171.84 (C—OEt), 91.38 (=CH2), 62.20 (O—CH2CH3) 14.49 (CH3—CO), −2.48 (Ge—CH3); yield =77.6%.
[0120] The α-germa-vinyl ether was then hydrolyzed to acetyltrimethylgermane with acid. The yield of the hydrolysis was dependent on the scale of hydrolysis. On a 0.010 mol scale, acidic hydrolysis (3N HCl/Et2O) gave the acetyl derivative in greater than 90% yields. However, on larger scale (0.14 mol), even with vigorous mechanical stirring, at best only 82% conversion was possible. The hydrolysis was monitored via TLC (10:1, hexane/ethyl acetate) to ascertain complete conversion to the ketone. After work-up and short path flash distillation at 62° C. and 40 mmHg, multinuclear NMR spectroscopy confirmed the product as acetyltrimethylgermane. 1H NMR (CDCl3):δ2.32 (s, 3H, —CH3), 0.35 (s, 9H,(Ge(Ch3)3). 13C NMR (CDCl3): δ244.92 C═O), 36.37 (Ch3—CO),−3.10 (Ge—CH3); Anal. Calcd for C5H12OGe: C, 37.36; H, 7.52. Found: C, 37.47; H, 7.76.
Preparation of 2,2,6,6-Tetramethyl-2-germa-3,5-heptanedione (tmghdH)
[0121] The germa-β-diketone, tmghH, was prepared by the reaction of acetyltrimethyl-germane (10 mmol) with freshly prepared LDA (10 mmol) in dry diethyl ether (50 mL) to generate the lithium enolate. After 30 minutes the enolate was slowly transferred to the second flask charged with anhydrous diethyl ether (50 mL) and trimethylacetylchloride, (10 mmol) and the reaction temperature was maintained between −110° C. and −85° C. After 1 hour, the reaction was essentially complete and was quenched with saturated ammonium chloride solution. Purification of the germa-β-diketone via flash column chromatography using hexane as eluant afforded the product. (61% yield) 1H and 13C NMR spectroscopy showed the diketone to exist as the enolic tautomer. 1H NMR (CDCl3): δ15.17 (s, 1H, OH), 5.84 (s, 1H,═CH), 1.14 (s, 9H, tBu—CH3),−0.33 (s, 9H, Ge—CH3). 13C NMR (CDCl3): δ207.80 (C═O), 199.17 (C—OH), 103.60 (═CH), 41.27 (C(Ch3)3), 27.02 (tBu—CH3), −3.10 (Ge—CH3); Anal. Calcd for C10H20O2Ge: C, 49.05; H, 8.23. Found: C, 50.71; H, 8.49.
[0122] The copper(II) complex, Cu(tmghd)2, was prepared by the method used above and was purified via sublimation (99° C., 0.1 mm Hg) (48% yield). Anal. Calcd for C20H38CuO4Ge2: C, 43.57; H, 6.95. Found: C, 43.80; H, 7.48. M.p.: 148° C.
[0123] Crystals of Cu(tmghd)2suitable for single crystal X-ray diffraction studies were obtained by controlled growth from pentane at 5° C. over 7 days. The complex was square planar with the copper atom located on a center of symmetry. Disorder associated with occupancy of the t-butyl and trimethylgermyl sites limited the accuracy of the structure determination. Modifying crystal growth parameters, such as solvent system, temperature, or even growth by slow sublimation, all yielded crystals with the same unit cell. Incorporation of the germanium atom into the βdiketonate architecture imposed modest structural differences when compared with a copper complex with the sila-β-diketonate 2,2,6,6-tetramethyl-2-sila-3,5-heptanedione (Cu(tmshd)2), consistent with the larger van der Waals radius of germanium.
[0124] Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) facilitated evaluation of the volatility and thermal stability of the copper complex. Following drying in vacuo,(60° C., 0.5 mm Hg) the complexes were analyzed in a dynamic dinitrogen atmosphere at ambient pressure. The sublimation of Cu(tmghd)2has an onset of 89° C., with less then 1% residue. Calculation of the derivative weight loss, (%/°C.), reveals the maximum rate of weight loss to occur at 155° C. Although Cu(tmghd)2has a molecular weight 28% greater than Cu(tmhd)2,it is more volatile. DSC analysis of a hermetically sealed sample of had a phase change attributed to melting at 148° C., with complete decomposition occurring after 200° C. is reached. Although Cu(tmghd)2displays apparently lower volatility than Cu(tmshd)2,Cu(tmghd)2has a much higher decomposition temperature.
Example 16
[0125] TGA and DSC Analysis of Copper Complexes α-Germa-β-Diketones
[0126] The thermal properties of copper complexes of other germyl ligands were prepared by the process illustrated in Example 15 were evaluated. Results appear in Table 4.
| TABLE 4 |
|---|
| Copper Complexes With Germyl Ligands |
Example 17
Preparation of Copper (II) Complex With (6,6-dimethyl-9,9,10,10,11,11,12, 12,13,13,14,14,15,15,16,16,16-heptadecafluoro-6-silahexadeca-3,5-dionate)(Cu[C
[0127] Acetyldimethyl-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecylsilane was synthesized from ethyl vinyl ether and chlorodimethyl-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-heptadecafluorodecylsilane after the procedure of Cunico and Kuan (J. Org. Chem.1985, 50, 5410-5413).
Preparation of 6,6-dimethyl-9,9,10,10,11,11,12,12,13,13,14,14,15,15,16,16,16-heptadecafluoro-6-silahexadeca-3,5-dione (C
[0128] A stirring solution of diisopropylamine (0.51 mL, 3.6 mmol) and Et2O (70 mL) in a 250 mL Schlenk flask was cooled to 0° C. n-BuLi (1.4 mL, 3.6 mmol, 2.5 M in hexanes) was added and the solution stirred for 1 h and then cooled to −50° C. A solution of acetyldimethyl-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecylsilane (2.0 g, 3.6 mmol) dissolved in Et2O (10 mL) was added slowly. After 1 h, the mixture of the enolate was cannulated to another 250 mL Schienk flask containing a solution of methyl pentafluoropropionate (0.47 mL, 3.7 mmol) in Et2O (40 mL) at −50° C. The mixture was stirred for 3 h at −50° C. and then quenched with aqueous saturated NH4Cl solution. The organic layer layer was separated, washed with water and dried with Na2SO4. Filtration followed by evaporation of the solvent in vacuo gave the crude product as a light yellow oil. Yield: 2.2 g, 87%. 1H NMR (CDCl3): δ6.12 (s, 1H), 2.2-2.0 (m, 2H), 1.0-0.9 (m, 2H), 0.30 (s, 6H). 19F: δ−81.66 (t, 3F, J=10.0 Hz),−83.71 (s, 3F),−116.77 (m, 2F),−122.64 (br, 6F),−123.46 (br, 2F),−123.98 (br, 2F),−124.9 (s, 2F),−126.90 (br, 2F).
Preparation of Copper(II) bis(6,6-dimethyl-9,9,10,10,11,11,12,12,13,13,14,14,15,15, 16,16,16-heptadecafluoro-6-silahexadeca-3,5-dionate) (Cu[C
[0129] The copper (II) complex with the heptadecafluorodecylsilane ligand above was prepared and isolated according to the procedure in Example 9. Single crystals suitable for X-ray diffraction studies were grown from CH2Cl2/ Hexane at room temperature. Anal. Calcd (found) for C34H22O4F44Si2Cu: C, 28.16 (28.37); H, 1.53 (1.76).
Examples 18-21
[0130] TGA and DSC Analysis of Copper Complexes
[0131] Volatility of copper (II) complexes with alkyl-substituted and fluoroalkyl-substituted silyl ligands was determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Following drying in vacuo,(60° C., 0.5 mm Hg) the complexes were analyzed in a dynamic nitrogen atmosphere at ambient pressure. Conditions for the DSC analyses were: ramp rate at 1° C./min in dry N2stream (100 cm3/min). Measurement conditions for TGA were: ramp rate at 10° C./min in dry N2stream (40 cm3/min). Derivative weight loss, (%/° C.), the maximum rate of weight loss was calculated and is listed in the following Tables as T50%.
Example 18
[0132] Copper (II) Complexes with Non-fluorinated Ligands
[0133] Thermal properties of copper (II) complexes with non-fluorinated ligands were determined as described above. Results appear in Table 5.
| TABLE 5 |
|---|
| Copper Complexes With Non-Fluorinated Ligands |
Example 20
[0134] Copper (II) Complexes with Ligands Containing Short-Chain Fluoroalkyl Group
[0135] Thermal properties of copper (II) complexes with ligands containing short-chain fluoroalkyl groups were determined as described above. Results appear in Table 6.
| TABLE 6 |
|---|
| Copper Complexes with Ligands Containing |
| Short-Chain Fluoroalkyl Groups |
Example 21
[0136] Copper (II) Complexes with Ligands Containing Long-Chain Fluoroalkyl Group
[0137] Thermal properties of copper (II) complexes with ligands containing long-Chain fluoroalkyl groups were determined as described above. Results appear in Table 7.
| TABLE 7 |
|---|
| Copper Complexes with Ligands Containing |
| Long-Chain Fluoroalkyl Group |
Example 22
[0138] Formation of Pd((Ch3)3CCOCHCOSi(Ch3)3)2
[0139] Palladium dichloride (0.12 g) was added to the sodium salt of IV in about 100 ml distilled THF. After about 13 hours, color of the solution changed from red to reddish green. The crude product was recovered and sublimed for purification, yielding an off-yellow product, 28% yield.
[0140] TGA: T50%142° C., 99.1% weight loss.
[0141] DSC: Melting point 147° C.; decomposition 347° C.
[0142] Elemental analysis: Calculated: C,47.56; H,7.58; Found: C,47.53; H,7.68,
Claims
What is claimed:
1. A compound of formula I:
wherein
R1is methyl, ethyl, isopropyl, n-propyl, isobutyl, s-butyl, n-butyl, CF3, C2F5,i-C3F7, n-C3F7, or —C(CH3)(CF3)2;
R2is H;
E1is Si or Ge;
R3, R4, and R5are independently C6or lower alkyl; and
Y and Z are O.
2. A compound according to claim 1, wherein E1is Ge.
3. A compound according to claim 2, wherein R1is methyl.
4. A compound according to claim 2, wherein R1is ethyl.
5. A compound according to claim 2, wherein R1is isopropyl.
6. A compound according to claim 2, wherein R1is n-propyl.
7. A compound according to claim 2, wherein R1is isobutyl.
8. A compound according to claim 2, wherein R1is s-butyl.
9. A compound according to claim 2, wherein R1is s-butyl.
10. A compound according to claim 2, wherein R1is n-butyl.
11. A compound according to claim 2, wherein R1is CF3.
12. A compound according to claim 2, wherein R1is C2F5.
13. A compound according to claim 2, wherein R1is i-C3F7.
14. A compound according to claim 2, wherein R1is n-C3F7.
15. A compound according to claim 2, wherein R1is C(CH3)(CF3)2.
16. A compound according to claim 1, wherein E1is Si.
17. A compound according to claim 16, wherein R3, R4, and R5are methyl.
18. A compound according to claim 16, wherein R3, R4, and R5are ethyl.
19. A compound according to claim 16, wherein R3, R4, and R5are t-butyl.
20. A compound according to claim 16, wherein R3, R4, and R5are isopropyl.
21. A compound according to claim 16, wherein R3and R4are methyl, and R5is C(CH3)2CH(CH3)2.
22. A metal-ligand complex of formula II:
M Ln·pD (II)
wherein
M is a metal chosen from the group consisting of: Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Ti, Zr, Hf, Pr, V, Nb, Ta, Nd, Cr, Mo, W, Mn, Re, Sm, Fe, Ru, Eu, Os, Co, Rh, Ir, Gd, Ni, Pd, Pt, Tb, Cu, Ag, Au, Dy, Ho, Al, Ga, In, Tl, Er, Ge, Sn, Pb, Tm, Sb, Bi, Yb, Lu, Th, and U, and mixtures thereof;
D is a neutral coordinating ligand;
n is equal to the valence of M;
p is zero or an integer from 1 to 6; and
L is a ligand of formula III:
wherein
R1is methyl, ethyl, isopropyl, n-propyl, isobutyl, s-butyl, n-butyl, CF3, C2F5, i-C3F7, n-C3F7, or —C(CH3)(CF3)2;
R2is H;
E1is Si or Ge;
R3, R4, and R5are independently C6or lower alkyl; and
Y and Z are O.
Patent Citations (2)
Non-Patent Literature (6)
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- Welch et al., “Silver Complexes for MOCVD”, Spring 2000 ACS National Meeting, Abstract only, 1 p., Mar. 2000.Applicant
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- Banger et al., “Facile Preparation and Isolation of Fluoroalkyl Sila-B-dikentones: The Influence of Silicon Substitution on the Properties of Fluoroalkyl Containing B-diketonate Cu(II) Complexes”, 16th International Symposiym Fluorine Chemistry, University of Durham, UK, (Jul. 16-21. 2000), Abstractonly, 2 pp.Applicant
- Claessen et al., “The 2,2,6,6-Tetramethyl-2-Sila-3,5-Heptanedione Route to the Chemical Vapor Deposition of Copper for Gigascale Interconnect Applications”, Spring MRS, San Francisco, California, (Apr. 24-Apr. 28, 2000), Abstract only, 2 pp.Applicant