JPWO2009011425A1 - Organic platinum complex and method for producing platinum-containing thin film by chemical vapor deposition using the platinum complex - Google Patents

Abstract

The organic platinum complex of the present invention is a novel platinum complex represented by the general formula (1), has a low melting point, is excellent in stability to moisture, air and heat, and is a platinum-containing thin film by CVD. Suitable for manufacturing. (Wherein X and Y each independently represent a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group, Z represents a hydrogen atom, Alternatively, it represents a linear or branched alkyl group having 1 to 4 carbon atoms, and L represents an alkoxyalkenyl group (a linear or branched alkenyl group substituted with an alkoxy group).

Description

  The present invention relates to a novel organic platinum complex and a method for producing a platinum-containing thin film by a chemical vapor deposition method (hereinafter referred to as a CVD method) using the platinum complex.

  In recent years, the use of platinum-containing thin films, preferably metallic platinum thin films, having excellent electrical characteristics, has been studied as thin film electrode materials for memory devices such as DRAM and FeRAM. As a method for producing these platinum-containing thin films, for example, film formation by the CVD method, which is easy to produce a uniform thin film, has been most widely adopted, and a raw material compound suitable for the film formation is required.

  By the way, as a platinum complex used in thin film formation by CVD method, (beta) -diketonato platinum complex and alkyl platinum complex are disclosed, for example (for example, refer nonpatent literature 1 and patent document 1). However, for example, a platinum complex consisting only of a β-diketonato ligand generally has a high melting point, and an alkyl platinum complex is chemically and thermally unstable. It was not always satisfactory in terms of physical properties.

Non-Patent Document 2 discloses a β-diketonato platinum complex having a cyclooctenyl group substituted with a methoxy group as a ligand, but there is no description regarding the production of a platinum-containing thin film by a CVD method. Moreover, since the platinum complex described is solid at room temperature, there is a concern about problems in use in the CVD method.
JP 2004-203744 A J. et al. Am. Chem. Soc. , 111 (24), 8779 (1989) Synth. React. Inorg. Met. -Org. Chem. 16 (2), 213 (1986)

  An object of the present invention is to solve the above problems, have a low melting point, and have excellent stability to moisture, air and heat, and a platinum-containing thin film by the CVD method, particularly a metal platinum thin film. The object is to provide a novel platinum complex suitable for production. The subject of this invention is also providing the manufacturing method of the platinum containing thin film by CVD method using the said platinum complex, especially the manufacturing method of a metal platinum thin film.

  The present invention relates to the following matters.

  1. General formula (1)

（式中、Ｘ及びＹは、それぞれ独立に、アルコキシ基で置換されていても良い炭素数１〜８の直鎖又は分枝状のアルキル基を示し、
Ｚは、水素原子、あるいは炭素数１〜４の直鎖又は分枝状のアルキル基を示し、
Ｌは、アルコキシアルケニル基（アルコキシ基で置換された直鎖又は分枝状のアルケニル基）を示す。）
で示される有機白金錯体。

(Wherein, X and Y each independently represent a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group,
Z represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,
L represents an alkoxyalkenyl group (a linear or branched alkenyl group substituted with an alkoxy group). )
An organic platinum complex represented by

  2. 2. The organoplatinum complex according to 1 above, wherein the alkoxy group in L has 1 to 4 carbon atoms.

  3. 2. The organoplatinum complex according to 1 above, wherein the alkenyl group in L has 4 to 10 carbon atoms.

  4). A method for producing a platinum-containing thin film by chemical vapor deposition using the organic platinum complex described in 1 above.

  5. 5. The method for producing a platinum-containing thin film according to 4 above, wherein an organic platinum complex or a solvent solution of the organic platinum complex is used as a platinum supply source.

  6). 6. The method for producing a platinum-containing thin film as described in 5 above, further using a hydrogen source.

  7). 7. The method for producing a platinum-containing thin film according to 6 above, wherein the hydrogen source is hydrogen gas.

  8). 6. The method for producing a platinum-containing thin film according to 5 above, further using an oxygen source.

  9. 9. The method for producing a platinum-containing thin film according to 8 above, wherein the oxygen source is oxygen gas.

  10. 6. The method for producing a platinum-containing thin film according to 5 above, wherein the solvent used is at least one solvent selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, and ethers.

  The organoplatinum complex represented by the general formula (1) of the present invention has a low melting point and excellent stability to moisture, air and heat, and is suitable for the production of a platinum-containing thin film by the CVD method. . Furthermore, by using this organic platinum complex as a platinum supply source, a metal platinum film substantially free of oxygen atoms can be produced by the CVD method.

It is a figure which shows the structure of a vapor deposition apparatus.

Explanation of symbols

1A mass flow controller 1B mass flow controller 2 stop valve 3 vaporizer 4 reactor 5 pressure gauge 6 valve 7 trap 10A preheater 10B vaporizer heater 10C reactor heater 20 raw material organic platinum complex melt 21 substrate

  In the general formula (1), X and Y each independently represent a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group. X and Y are preferably an alkyl group having 1 to 6 carbon atoms which may be substituted with an alkoxy group, and particularly preferably an alkyl group having 1 to 3 carbon atoms which may be substituted with an alkoxy group. As an alkoxy group which is a substituent, a C1-C3 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is especially preferable.

  Examples of X and Y include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 1-methoxy group. Examples thereof include an ethyl group and a 1-ethoxyethyl group, preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and a 1-methoxyethyl group, and particularly preferably a methyl group. It is also particularly preferred that X is an isopropyl group and Y is a 1-methoxyethyl group.

  Z represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

  Examples of Z include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group, and preferably a hydrogen atom, a methyl group, or an ethyl group. A group, particularly preferably a hydrogen atom.

  As the β-diketonato ligand, X and Y are methyl groups and Z is a hydrogen atom, or X is an isopropyl group, Y is a 1-methoxyethyl group, and Z is a hydrogen atom Particularly preferred are those wherein X and Y are methyl groups, and Z is a hydrogen atom.

  L represents an alkoxyalkenyl group, that is, a linear or branched alkenyl group substituted with an alkoxy group. As shown by the formula described below, the carbon-carbon double bond of the alkenyl group is usually considered to be coordinated to Pt.

  As an alkoxy group in L, a C1-C4 thing is preferable, a methoxy group, an ethoxy group, and an isopropoxy group are more preferable, and a methoxy group and an ethoxy group are especially preferable.

  The alkenyl group in L is preferably one having 4 to 10 carbon atoms, more preferably one having 4 to 6 carbon atoms, and particularly preferably one having 6 carbon atoms (hexenyl group).

  The substitution position of the alkoxy group is not particularly limited, but is preferably the 2-position when the carbon atom bonded to Pt is the 1-position. Even when the alkenyl group is branched, the substitution position of the alkoxy group is not particularly limited, and the alkoxy group may be bonded to any carbon atom.

  As L, those represented by the following general formulas (1-1) to (1-3) are preferable, and those represented by the following general formula (1-1) are particularly preferable.

（式中、ＯＲは、炭素数１〜４のアルコキシ基を示し、
Ｒａは、炭素数２〜４の直鎖アルケニル基を示し、
Ｒｂは、メチル基又はエチル基を示す。）

(In the formula, OR represents an alkoxy group having 1 to 4 carbon atoms,
Ra represents a linear alkenyl group having 2 to 4 carbon atoms,
Rb represents a methyl group or an ethyl group. )

  As L, for example, 2-methoxy-5-hexenyl group, 2-methoxy-4-pentenyl group, 2-methoxy-3-butenyl group, 2-ethoxy-5-hexenyl group, 2-ethoxy-4-pentenyl group 2-ethoxy-3-butenyl group, 2-butoxy-5-hexenyl group, 2-butoxy-4-pentenyl group, 2-butoxy-3-butenyl group, 1-methyl-2-methoxy-3-pentenyl group, 1-methyl-2-ethoxy-3-pentenyl group, 2-isopropoxy-5-hexenyl group, 2-isopropoxy-4-pentenyl group, 2-isopropoxy-3-butenyl group, 1-methoxymethyl-4- Pentenyl group, 1-ethoxymethyl-4-pentenyl group and the like can be mentioned, but preferably 2-methoxy-5-hexenyl group, 2-methoxy-4-pentenyl group 2-ethoxy-5-hexenyl group, 2-ethoxy-4-pentenyl group, 2-isopropoxy-5-hexenyl group, 2-isopropoxy-4-pentenyl group, 1-ethoxymethyl-4-pentenyl group, Particularly preferred are 2-methoxy-5-hexenyl group, 2-ethoxy-5-hexenyl group, 2-isopropoxy-5-hexenyl group, 1-ethoxymethyl-4-pentenyl group, and more preferred is 2-methoxy- 5-hexenyl group, 2-ethoxy-5-hexenyl group, 1-ethoxymethyl-4-pentenyl group.

  Examples of specific compounds of the organic platinum complex of the general formula (1) of the present invention are represented by the following formulas (2) to (33).

  Especially, as a raw material compound for CVD, the organic platinum complex shown by said formula (2)-(5), (22)-(25), (26)-(27) is preferable, and said formula (2)-( 4) The organic platinum complexes represented by (26) to (27) are more preferred, and the organic platinum complexes represented by the above formulas (2) to (3) and (26) to (27) are particularly preferred.

  The organoplatinum complex represented by the general formula (1) of the present invention includes, for example, a platinum compound such as a halogenated platinic acid, for example, hexachloroplatinic acid, and a ligand (in the ligand L) in water or an organic solvent. The platinum complex (diene complex) having one diene ligand is synthesized by reacting with a diene compound to be an alkenyl group of the above-mentioned alkenyl group, and then isolated, and then the obtained diene complex in an organic solvent And a metal alkoxide containing an alkoxy group that becomes an alkoxy group in the ligand L and a β-diketone compound that becomes a ligand to synthesize the organoplatinum complex of the present invention, which is then isolated. Can be obtained. Further, the organic platinum complex of the present invention comprises a platinum compound such as a halogenated platinate, for example, potassium tetrachloroplatinate (II), and a ligand (ligand L) in water or a water-organic solvent mixed solvent. After the reaction with the diene compound to be an alkenyl group in the solvent, the solvent is removed, and then an organic solvent is added thereto, and a metal alkoxide containing an alkoxy group to be an alkoxy group in the ligand L is added to react. Then, a β-diketone compound as a ligand is added and reacted to synthesize the organoplatinum complex of the present invention, and then it can be isolated.

  In the CVD method of the present invention, it is necessary to vaporize the organic platinum complex in order to form a thin film. As a method of vaporizing the organic platinum complex of the present invention, for example, the organic platinum complex itself is filled or transported into the vaporization chamber. In addition to the method of vaporizing, an organic platinum complex is converted into an appropriate solvent (for example, aliphatic hydrocarbons such as hexane, methylcyclohexane, ethylcyclohexane, and octane; aromatic hydrocarbons such as toluene; tetrahydrofuran, dibutyl ether, etc. The method can be used in which the solution diluted in (1) is introduced into the vaporizing chamber by a liquid transfer pump and vaporized (solution method).

  The metal can be deposited on the substrate by a known CVD method. For example, the organic platinum complex can be converted into a hydrogen source (for example, a reducing gas such as hydrogen gas or alcohol under normal pressure or reduced pressure). ), An oxygen source (for example, oxygen gas), or a method in which a platinum-containing thin film is deposited by feeding it onto a substrate heated with an inert gas. Moreover, the method of vapor-depositing a platinum containing thin film by plasma CVD method can also be used. Note that a gas serving as a hydrogen source such as hydrogen and a gas serving as an oxygen source such as oxygen may be diluted with an inert gas.

  When the platinum-containing thin film is deposited using the organic platinum complex and a hydrogen source, an oxygen source or an inert gas, the pressure in the reaction system is preferably 1 Pa to 200 kPa, more preferably 10 Pa to 110 kPa. The temperature of the object (substrate temperature) is preferably 50 to 500 ° C, more preferably 100 to 400 ° C. The content ratio of the hydrogen gas or oxygen gas to the total gas amount when the metal thin film is deposited by hydrogen gas or oxygen gas is preferably 0.01 to 95% by volume, more preferably 0.1 to 90% by volume. is there.

  Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

Reference Example 1 [Synthesis of dichloro (1,5-hexadiene) platinum (II)]
3.97 g (7.66 mmol) of hexachloroplatinic acid hexahydrate was placed in a flask having an internal volume of 100 ml equipped with a stirrer, a thermometer and a dropping funnel, and dried at 65 ° C. for 1 hour under reduced pressure. Then, after cooling to room temperature, 18 ml of acetic acid was added. Subsequently, it heated to 65 degreeC and 4.15 g (50.5 mmol) of 1, 5-hexadiene was dripped, and it was made to react at the same temperature for 10 hours, stirring. After completion of the reaction, the reaction solution was cooled to room temperature, 35 ml of methylene chloride and 50 ml of water were added, and the organic layer was separated and concentrated. 100 ml of hexane was added to the obtained concentrated liquid to precipitate a white solid. After filtration, the residue was washed with hexane and dried at room temperature under reduced pressure to obtain 2.12 g of dichloro (1,5-hexadiene) platinum (II) as a white solid (isolated yield; 80% ).

  The physical properties of dichloro (1,5-hexadiene) platinum (II) were as follows.

IR (neat (cm ⁻¹ )); 3070, 3016, 2964, 2941, 1511, 1457, 1425, 1402, 1306, 1115, 1009, 941, 862, 776, 595, 508
¹ H-NMR (CDCl ₃ , δ (ppm)); 2.29 to 2.41 (2H, m), 2.68-2.80 (2H, m), 4.04 to 4.28 (2H, m), 4.50-5.24 (2H, m), 5.67-5.78 (2H, m)
MS (m / e); 348, 312, 274, 233, 67, 41

Example 1 Synthesis of [(acetylacetonato) (2-methoxy-5-hexenyl) platinum (II) (compound of formula (2); hereinafter referred to as [Pt (acac) (moh)]), starting material; Dichloro (1,5-hexadiene) platinum (II)]
To a 100 ml flask equipped with a stirrer, thermometer and dropping funnel, 3.53 g (18.3 mmol) of 28% sodium methoxide methanol solution was added, and dichloro (1,5-hexadiene) platinum (II) was cooled with water. ) A solution prepared by dissolving 1.56 g (4.49 mmol) in 15 ml of methylene chloride was added dropwise. Next, 2.10 g (21.0 mmol) of acetylacetone was added and reacted at the same temperature for 1 hour with stirring. After completion of the reaction, the organic layer was separated from the reaction solution, washed with water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated, and the concentrate was distilled under reduced pressure (140 ° C., 47 Pa) to give (acetylacetonato) (2-methoxy-5-hexenyl) platinum (II) 1. 70 g was obtained (isolation yield; 93%). The pale yellow viscous liquid became a white solid (melting point: 88-91 ° C.) with time.

  In addition, (acetylacetonato) (2-methoxy-5-hexenyl) platinum (II) is a novel compound represented by the following physical property values.

IR (neat (cm ⁻¹ )); 2928, 2874, 2820, 1584, 1515, 1386, 1263, 1134, 1080, 949, 903, 775, 618, 451
(A peak peculiar to β-diketone (1622 cm ⁻¹ ) disappeared, and a peak peculiar to β-diketonato (1584 cm ⁻¹ ) was observed)
Elemental analysis _{(C 12 H 20 O 3 Pt} ); Carbon: 35.5%, hydrogen: 4.98% platinum: 47.9%
(Theoretical value: carbon: 35.38%, hydrogen: 4.95%, platinum: 47.89%)
MS (m / e); 407, 375, 307, 275, 235, 43

Example 2-1 Synthesis and start of [(acetylacetonato) (2-ethoxy-5-hexenyl) platinum (II) (compound of formula (3); hereinafter referred to as [Pt (acac) (eoh)]) Raw material; dichloro (1,5-hexadiene) platinum (II)]
Sodium ethoxide (3.53 g, 18.3 mmol) and ethanol (8 ml) were added to a 100 ml flask equipped with a stirrer, thermometer and dropping funnel, and dichloro (1,5-hexadiene) platinum (II) was added with water cooling. A solution prepared by dissolving 1.62 g (4.66 mmol) in 12 ml of methylene chloride was added dropwise. Next, 3.00 g (30.0 mmol) of acetylacetone was added, and the mixture was reacted at the same temperature for 1 hour with stirring. After completion of the reaction, the organic layer was separated from the reaction solution, washed with water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated, and the concentrate was distilled under reduced pressure (140 ° C., 33 Pa) to give (acetylacetonato) (2-ethoxy-5-hexenyl) platinum (II) as a pale yellow viscous liquid. 71 g were obtained (isolation yield; 87%).

  In addition, (acetylacetonato) (2-ethoxy-5-hexenyl) platinum (II) is a novel compound represented by the following physical property values.

IR (neat (cm ⁻¹ )); 2971, 2926, 1583, 1516, 1389, 1265, 1083, 780, 614, 447
(A peak peculiar to β-diketone (1622 cm ⁻¹ ) disappeared, and a peak peculiar to β-diketonato (1583 cm ⁻¹ ) was observed)
Elemental analysis _{(C 13 H 22 O 3 Pt} ); Carbon: 37.1%, hydrogen: 5.30% platinum: 46.3%
(Theoretical value: carbon: 37.05%, hydrogen: 5.26%, platinum: 46.29%)
MS (m / e); 421, 376, 321, 276, 235, 43

Example 2-2 Synthesis of [(acetylacetonato) (2-ethoxy-5-hexenyl) platinum (II) (compound of formula (3); hereinafter referred to as [Pt (acac) (eoh)]), starting Raw material: Potassium tetrachloroplatinate (II)]
To a 100 ml flask equipped with a stirrer, a thermometer and a dropping funnel, 5.55 g (13.4 mmol) of potassium tetrachloroplatinate (II) was added, 20 ml of water and 10 ml of acetic acid were added, and 1,5 -Hexadiene 11.7g (143 mmol) was added and it stirred at 60 degreeC for 6 hours. The resulting suspension was allowed to stand overnight at room temperature, and then the suspension was concentrated to give a pale yellow solid. 25 ml of ethanol was added to the obtained solid, and 13.65 g (59.3 mmol) of a 20% sodium ethoxide ethanol solution was added dropwise at 10 ° C. with stirring. After dropping, the mixture was stirred at 10 ° C. for 2 hours to obtain a pale yellow suspension. To the resulting suspension, 5.35 g (53.4 mmol) of acetylacetone was added dropwise and reacted at the same temperature for 1 hour with stirring. After completion of the reaction, the reaction solution was concentrated to obtain a yellow slurry. After adding methylcyclohexane and water to the slurry, the organic layer was separated, washed with water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated, and the concentrate was distilled under reduced pressure (140 ° C., 11 Pa) to give 4.65 g of (acetylacetonato) (2-ethoxy-5-hexenyl) platinum (II) as a pale yellow viscous liquid. (Isolated yield; 82%).

Examples 3 to 6 (deposition experiment; production of metal platinum thin film)
Using the organoplatinum complexes obtained in Examples 1 and 2-1 ([Pt (acac) (moh)] and [Pt (acac) (eoh)])), a vapor deposition experiment by a CVD method was performed, and film formation characteristics were obtained. Evaluated.

  The apparatus shown in FIG. 1 was used for the evaluation test. The organoplatinum complex 20 in the vaporizer 3 (glass ampule) is heated and vaporized by the heater 10B, exits the vaporizer 3 along with the helium gas introduced after preheating by the preheater 10A via the mass flow controller 1A. The gas exiting the vaporizer 3 is introduced into the reactor 4 together with the hydrogen gas or oxygen gas introduced through the mass flow controller 1B and the stop valve 2. The pressure in the reaction system is controlled to a predetermined pressure by opening and closing the valve 6 in front of the vacuum pump, and is monitored by the pressure gauge 5. The central part of the glass reactor has a structure that can be heated by the heater 10C. The platinum complex introduced into the reactor is set in the center of the reactor and reacts on the surface of the deposition target substrate 21 heated to a predetermined temperature by the heater 10C, so that a metal platinum thin film is deposited on the substrate 21. . The gas exiting the reactor 4 is exhausted to the atmosphere via a trap 7 and a vacuum pump.

  The deposition conditions and deposition results (film characteristics) are shown in Table 1. In addition, as a to-be-deposited board | substrate, the rectangular thing of 7 mm x 20 mm size was used.

  The results show that the organoplatinum complexes ([Pt (acac) (moh)] and [Pt (acac) (eoh)]) have excellent film forming properties at low temperatures.

  According to the present invention, a novel organic platinum complex having a low melting point and excellent stability to moisture, air and heat, and suitable for producing a platinum-containing thin film by a CVD method, and the organic platinum complex The manufacturing method of the metal platinum containing thin film by the used CVD method can be provided.

Claims (10)

General formula (1)

(Wherein, X and Y each independently represent a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group,
Z represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,
L represents an alkoxyalkenyl group (a linear or branched alkenyl group substituted with an alkoxy group). )
An organic platinum complex represented by   The organoplatinum complex according to claim 1, wherein the alkoxy group in L has 1 to 4 carbon atoms.   The organoplatinum complex according to claim 1, wherein the alkenyl group in L has 4 to 10 carbon atoms.   A method for producing a platinum-containing thin film by chemical vapor deposition using the organic platinum complex according to claim 1.   The method for producing a platinum-containing thin film according to claim 4, wherein an organic platinum complex or a solvent solution of the organic platinum complex is used as a platinum supply source.   Furthermore, the manufacturing method of the platinum containing thin film of Claim 5 using a hydrogen source.   The method for producing a platinum-containing thin film according to claim 6, wherein the hydrogen source is hydrogen gas.   Furthermore, the manufacturing method of the platinum containing thin film of Claim 5 using an oxygen source.   The method for producing a platinum-containing thin film according to claim 8, wherein the oxygen source is oxygen gas.   The method for producing a platinum-containing thin film according to claim 5, wherein the solvent to be used is at least one solvent selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons and ethers.

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