JPH05106045A - Metallic acetyl acetonato-complex for forming oxide thin film - Google Patents

Abstract

PURPOSE:To develop a raw material which can form an oxide thin film with good reproducibility by a chemical vapor deposition method at a low temp. by combining a metallic complex contg. specific acetyl acetone and the adduct of an orthophenanthroline deriv., etc. CONSTITUTION:The metal acetyl acetonato [Ba(acac)2(phen)2]complex is produced by bringing the adduct of the orthophenanthroline deriv., etc., such as 1,10-phenanthroline [phen], or the adduct of a 2,2'-pyridyl deriv., such as 4,4'-dimethyl-2,2'-bipyridyl, into reaction with the bis-2,4-pentadionatobarium [Ba(acac)2] contg. the acetyl acetone expressed by general formula [I] (where M is a metal of (n) valency) as the orientation position. The oxide thin film is stably formed with the excellent reproducibility on a substrate by a vapor phase deposition method under a reduced pressure using such complex as the raw material and using the reaction with O2, water, NO, O3, etc., and He, Ar, etc., as a carrier gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal complex for forming an oxide thin film, which is composed of an adduct of a metal acetylacetonato complex and is used in a vapor deposition method or the like.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Regarding β-diketone complexes of alkaline earth metals, Ino
organic Chemistry Vol. 2 No.
1, P. 73, 1963, the synthetic method and the purification method, and Analytical Chemistry Vol.
42 No. 14, P.I. In 1828 and 1970, vaporization characteristics and the like due to thermal weight reduction are reported. When these raw materials are used in the chemical vapor deposition method, there is a problem that the vaporization temperature is high and the piping and the like have to be heated to 200 ° C. or higher. For this reason, it has been desired to lower the vaporization temperature. An attempt to lower the vaporization temperature of a raw material gas by mixing tetrahydrofuran or 1,4-dioxane into a carrier gas has been reported in Autumn 1989, 50th Annual Meeting of the Society of Applied Physics, Lecture No. 30a-M-2.

In addition, EUROPEAN PATEN
It has been reported in APPLICATION 902014855.1 that the supply amount of the raw material gas is stabilized by a volatile metal complex composed of an alkaline earth metal β-diketone complex and a neutral oxygen or neutral nitrogen donor ligand. However, in the method in which tetrahydrofuran is mixed in the carrier gas, a large amount of tetrahydrofuran is present during the production of the thin film, and thus this decomposition product is easily incorporated as an impurity.
In addition, M (DPM) ₂ −L ₂ {M = Ba, Sr, Ca,
Mg: L = alcohol, cyclic ether, acyclic ether, ketone, diamine, aldehyde, pyridine, amii, imine, diimine} is required to vaporize 200
It was found that when heated to a temperature of ℃ or more, the added ligand L is dissociated and the initial vaporization characteristics cannot be continued.

As a result of extensive studies, the present inventor has found that an adduct of a metal complex having an acetylacetone ligand as a ligand and an orthophenanthroline derivative or 2,2-
We have found that the vaporization temperature of a compound consisting of an adduct of a bipyridyl derivative can be extremely lowered, and that it is useful as a material for forming an oxide thin film, and completed the present invention.

[0005]

That is, the present invention is based on the general formula (Wherein M is an n-valent metal) and a metal complex having acetylacetone as a ligand and an adduct of an orthophenanthroline derivative or an adduct of a 2,2′-bipyridyl derivative. It is a metal acetylacetonato complex for forming an oxide thin film.

[0006]

The present invention will be described in more detail below. The present invention relates to an adduct of a metal complex having acetylacetone as a ligand and an orthophenanthroline derivative or 2,2'-
The most important feature is that the compound is an adduct of a bipyridyl derivative.

As described above, the metal acetylacetonato complex as an adduct is excellent as a raw material for forming an oxide thin film. The vaporization temperature is significantly lower than that of the conventional one. For example, Ba (DPM) ₂ (phen) ₂ has a pressure of 15
Torr-N ₂ carrier flow rate 20 ml / min. The vaporization start temperature is about 200 ° C under the conditions of
ac) ₂ (phen) ₂ has a vaporization start temperature of about 1 under the same conditions.
It is 20 ° C., and the vaporization temperature is reduced to about 80 ° C., which is extremely useful industrially.

An example of a metal complex represented by the formula (1) and having acetylacetone as a ligand is as follows: bis-2,4-pentanedionatobarium [Ba (acac) ₂ ] bis-2,4- Pentanedionatostrontium [Sr (acac) ₂ ] bis-2,4-pentanedionatocalcium [Ca (acac) ₂ ] bis-24-pentanedionatemagnesium [Mg (acac) ₂ ] bis-2,4-pentane Dionato copper [Cu (acac) ₂ ] bis-2,4-pentanedionatnickel [Ni (acac) ₂ ] bis-2,4-pentanedionatolead [Pb (acac) ₂ ] Tris-2,4- Pentanedionat Bismuth [Bi (acac) ₃ ] Bis-2,4-pentanedionato Silver [Ag (acac) ₂ ] Lis-2,4-pentanedionato indium [In (acac) ₃ ] Tris-2,4-pentanediononatrantanide [La (acac) ₃ ] and the like can be mentioned.

Examples of orthophenanthroline derivatives include 1,10-phenanthroline [phen] 4,7-dimethyl-1,10-phenanthroline 4,7-diphenyl-1,10-phenanthroline 4,7-diphenyl-2,9-dimethyl. -1,10-phenanthroline etc. are mentioned.

Examples of the 2,2'-bipyridyl derivative include 2,2'-bipyridyl [bpy] 4,4'-dimethyl-2,2'-bipyridyl.

The vaporization characteristics can be seen in the thermogravimetric reduction by a thermobalance. Thermal weight reduction means vacuum 15 to 20 torr
A nitrogen carrier of about 20 ml / min. 5 ° C /
min. Is the value of the weight reduction when the temperature is raised from room temperature to 500 ° C. at a constant heating rate. From this, the vaporization start temperature can be seen.

When a thin film is formed using the metal complex for forming an oxide thin film of the present invention, there are a liquid phase deposition method and a vapor phase deposition method, and a vapor phase deposition method is particularly preferable.

When a thin film is formed using the metal complex for forming an oxide oxide thin film of the present invention, it is preferably under pressure, under normal pressure or under reduced pressure.

When a thin film is formed using the metal complex for forming an oxide thin film of the present invention, the entrained gas may be helium, argon, nitrogen, etc., and the reaction gas may be oxygen, water, nitrous oxide, ozone, etc. is there.

[0015]

The present invention will be described in detail below, but the present invention is not limited to these examples.

Preparation and Example 1 Preparation Example of [Ba (acac) ₂ (phen) ₂ ] 2.4 g of 1,10-phenanthroline 1 in an aqueous solution in which 1.7 g of barium hydroxide octahydrate was dissolved. The ethanol solution in which the hydrate was dissolved was added dropwise at room temperature, and after stirring and mixing, 1.37 g of acac was added dropwise at room temperature to complete the reaction in about 1 hour. Next, water was added to this reaction solution for crystallization,
It was filtered to obtain 3.6 g of the target compound. Furthermore, this target compound was purified by recrystallization using ethanol, and 3.2 g of the target compound was recovered. Elemental analysis: measured value (calculated value) (%) C58.59 (58.62); H4.97 (4.8)
8); N 8.04 (8.05); Ba 19.73 (1)
9.73)

In FIG. 1A, Ba (DPM) ₂ (phe
n) ₂ and Ba (acac) ₂ (phen) in FIG. 1 (b).
₂ shows a thermal weight loss of ₂ . Ba (DPM) ₂ (phen)
Vaporization start temperature of ₂ is about 200 ℃, Ba (aca
c) The vaporization starting temperature of ₂ (phen) ₂ is about 120 ° C. and B
The temperature of a (DPM) ₂ (phen) _{2 is} lowered by 80 ° C. It is extremely useful industrially to realize vaporization at 200 ° C or lower.

Preparation and Example 2 [Sr (acac) ₂ (phen) ₂ ] An aqueous solution containing ₂ g of strontium hydroxide octahydrate and a methanol solution containing 3.1 g of 1,10-phenanthroline were dissolved. After stirring and mixing at 45 ° C. for 6 hours, acac 1.7 g
The mixture was added dropwise at room temperature and the reaction was completed in about 3 hours. Next, methanol was removed from this reaction solution under reduced pressure for crystallization, and then filtration was performed to obtain 4.7 g of the target compound. Further, this target compound was purified by recrystallization using methanol to recover 4.2 g of the target compound. Elemental analysis: measured value (calculated value) (%) C63.08 (63.13); H5.33 (5.2)
6); N8.64 (8.67); Sr13.56 (1
3.56)

The vaporization start temperature of Sr (DPM) ₂ is about 2
It was 00 ° C., and the vaporization start temperature of Sr (acac) ₂ (phen) ₂ was about 115 ° C. The vaporization start temperature of about 85 ° C. could be lowered.

Production and Example 3 [Sr (acac) ₂ (bpy)] 2.1 g of an aqueous solution containing strontium hydroxide octahydrate dissolved therein and 1.6 g of methanol containing 2,2′-bipyridyl dissolved therein. 4 solutions
After stirring and mixing at 5 ° C. for 6 hours, 1.8 g of acac was added dropwise at room temperature to complete the reaction in about 3 hours. Next, methanol was removed from this reaction solution under reduced pressure for crystallization, and then filtration was performed to obtain 3.3 g of the target compound. Further, this target compound was recrystallized and purified using methanol to recover 2.9 g of the target compound. Elemental analysis: measured value (calculated value) (%) C54.24 (54.30); H5.00 (4.9)
8); N6.31 (6.33); Sr19.82 (1
9.82)

The vaporization start temperature of Sr (DPM) ₂ is about 2
The temperature was 00 ° C., and the vaporization start temperature of Sr (acac) ₂ (bpy) was about 110 ° C. The vaporization start temperature of about 90 ° C could be lowered.

Preparation and Example 4 [Cu (acac) ₂ (phen)] 30 g of copper acetate 1
37.24 g of 1,10 in an aqueous solution of hydrate
-Methanol solution containing phenanthroline was added dropwise at room temperature, and the mixture was stirred and mixed for about 1 hour.
3.4 g of acac was added dropwise and stirred to complete the reaction in about 2 hours. Next, methanol was removed from this reaction solution under reduced pressure for crystallization, and then filtration was performed to obtain 64 g of the target compound. Furthermore,
The target compound was purified by recrystallization using methanol to recover 60 g of the target compound. Elemental analysis: measured value (calculated value) (%) C59.69 (59.73); H5.49 (5.4)
3); N6.36 (6.33) Ba14.38 (14.
38)

The vaporization starting temperature of Cu (DPM) ₂ is about 1
The temperature was 10 ° C., and the vaporization start temperature of Cu (acac) ₂ (bpy) was about 50 ° C. It was possible to lower the vaporization start temperature of about 60 ° C.

Experimental Example 1 Using a metal organic chemical vapor deposition (hereinafter referred to as MOCVD) apparatus, a MgO substrate was heated to 300 ° C. in a reaction chamber and argon was used as a carrier gas for Ba (acac) _2.
(Phen) ₂ was vaporized and introduced. Further, by introducing oxygen into this reaction chamber at the same time, a good BaO thin film could be formed. The film forming rate was 1 to 10 μm / h.

Ba (acac) ₂ (phen) ₂ container temperature; 100 to 130 ° C. Carrier gas flow rate; 150 sccm Oxygen gas flow rate; 200 sccm * sccm is Standard Cubic Cen
It is an abbreviation for "timer per Minute" and is a volume (cm ³ ) of a gas flowing in 1 minute at 0 ° C. and 1 atm.

Experimental Example 2 Using an apparatus for MOCVD, the MgO substrate was heated to 750 ° C. and argon was used as a carrier gas for Sr (aca).
c) ₂ (phen) ₂ was vaporized and introduced. Here, by introducing oxygen at the same time, a good BaO thin film could be formed. The film forming rate was 1 to 10 μm / h.

Sr (acac) ₂ (phen) ₂ container temperature; 90 to 120 ° C. Carrier gas flow rate; 150 sccm

Experimental Example 3 Using an apparatus for MOCVD, a SrTiO ₃ substrate was heated to 750 ° C. in a reaction chamber, and Sr (acac) ₂ (bpy) was vaporized and introduced using argon gas as a carrier gas. By introducing oxygen at the same time, good SrO
A thin film could be formed.

The film forming rate was 3 to 15 μm / h. Sr (acac) ₂ (bpy) Container temperature; 90 to 120 ° C. Carrier gas flow rate; 150 sccm Oxygen flow rate; 200 sccm

Experimental Example 4 Using an apparatus for MOCVD, a SrTiO ₃ substrate was heated to 800 ° C. in a reaction chamber, and Cu (acac) ₂ (phen) was vaporized and introduced using argon gas as a carrier gas. By introducing steam at the same time, good S
An rO thin film could be formed. Deposition rate is 5 to 20
It was μm / h.

Cu (acac) ₂ (phen)) container temperature; 50 to 70 ° C. carrier gas flow rate; 200 sccm water vapor flow rate; 150 sccm

[0032]

By using the metal acetylacetonato complex for forming an oxide thin film of the present invention, it becomes possible to form an oxide thin film at a low temperature. Further, it is possible to form a stable and highly reproducible oxide thin film by the chemical vapor deposition method, which is extremely useful in industry.

[Brief description of drawings]

FIG. 1A shows a conventional Ba (DPM) ₂ (phe).
n) ₂ shows the thermogravimetric reduction (%), and (b) shows Ba (a
It is a diagram which shows the thermogravimetric reduction (%) of cac) ₂ (phen) ₂ .

Claims (1)

[Claims] 1. General formula Oxidation comprising a metal complex represented by the formula (M is an n-valent metal) having acetylacetone as a ligand and an adduct of an orthophenanthroline derivative or an adduct of a 2,2′-bipyridyl derivative. Metal acetylacetonato complex for thin film formation.