JP2016141882A - Production method of aluminum-containing oxide thin film, and aluminum-containing oxide thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an aluminium-containing oxide thin film capable of improving a deposition rate of the aluminium-containing oxide thin film, and to provide an aluminium-containing oxide thin film produced by the production method.SOLUTION: An aluminium-containing oxide thin film is deposited by an atomic layer deposition method by using an aluminium-containing composition containing trimethylaluminum and dimethylaluminum hydride and an oxygen-containing compound containing oxygen atoms as raw materials.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing an aluminum-containing oxide thin film and an aluminum-containing oxide thin film.

  Conventionally, aluminum-containing oxide thin films such as aluminum oxide thin films have been widely used as coating films for various machine parts, gate insulating films for semiconductor integrated circuits, barrier films in the field of organic electronics, and the like.

As a method for producing such an aluminum-containing oxide thin film, for example, a method of forming an aluminum oxide film by atomic layer deposition (ALD) using trimethylaluminum and O ₂ or O ₃ is proposed. (For example, refer to Patent Document 1).

JP 2010-98141 A

  The atomic layer deposition method, which is one of the thin film deposition methods, is widely used from the viewpoint of film thickness uniformity and high step coverage. On the other hand, the slow deposition rate has been pointed out as a problem.

  As described in Patent Document 1, the atomic layer deposition method is also used in a method of forming an aluminum oxide film, and trimethylaluminum is used as the only aluminum source for the aluminum source.

  The present invention is produced by a method for producing an aluminum-containing oxide thin film capable of improving the film formation rate of an aluminum-containing oxide thin film by using an aluminum source in place of trimethylaluminum, and produced by the method. The object is to provide an aluminum-containing oxide thin film.

  The method for producing an aluminum-containing oxide thin film of the present invention includes an aluminum-containing oxide thin film formed by an atomic layer deposition method using an aluminum-containing composition containing trimethylaluminum and dimethylaluminum hydride and an oxygen-containing compound containing oxygen atoms as raw materials. It is characterized by forming a film.

  According to such a method, by using an aluminum-containing composition containing trimethylaluminum and dimethylaluminum hydride as an aluminum source, the deposition rate of an aluminum-containing oxide thin film can be improved in an atomic layer deposition method. Thus, productivity of the aluminum-containing oxide thin film can be improved.

  In addition, since the number of moles of methyl groups contained in the aluminum-containing composition is reduced as compared with the case where the aluminum-containing composition is made of only trimethylaluminum, the aluminum-containing oxide film is formed by atomic layer deposition. It can suppress that the carbon originating in a methyl group remains in a thin film. Therefore, the film performance of the aluminum-containing oxide thin film can be improved.

  In the aluminum-containing composition, it is preferable that a molar ratio of the trimethylaluminum to the dimethylaluminum hydride is 4: 6 to 8: 2.

  According to such a method, in the aluminum-containing composition, when the molar ratio of trimethylaluminum: dimethylaluminum hydride is in the range of 4: 6 to 8: 2, trimethylaluminum and dimethylaluminum hydride in the vapor of the aluminum-containing composition. The composition ratio becomes a constant value.

  Therefore, when forming a film by the atomic layer deposition method, the molar ratio of trimethylaluminum: dimethylaluminum hydride can be stably maintained at a single value even in the gas of the aluminum-containing composition. As a result, the aluminum-containing oxide thin film can be stably formed.

  The aluminum-containing oxide thin film is preferably an aluminum oxide thin film.

  According to such a method, since the aluminum-containing oxide thin film is an aluminum oxide thin film, an aluminum oxide thin film having excellent film performance can be efficiently produced.

  Moreover, the aluminum containing oxide thin film of this invention is manufactured by said manufacturing method of an aluminum containing oxide thin film.

  Therefore, the aluminum-containing oxide thin film is efficiently produced by the above-described manufacturing method, carbon remaining in the aluminum-containing oxide thin film can be reduced, and film performance can be improved.

  In the method for producing an aluminum-containing oxide thin film of the present invention, the film forming speed of the aluminum-containing oxide thin film can be improved, and the productivity of the aluminum-containing oxide thin film can be improved.

  In addition, the aluminum-containing oxide thin film of the present invention can be produced efficiently and the film performance can be improved.

FIG. 1 shows the correlation between temperature and vapor pressure of an aluminum-containing composition in which the molar ratio of trimethylaluminum (TMA), dimethylaluminum hydride (DMAH) and trimethylaluminum: dimethylaluminum hydride is 6.6: 3.4. It is a graph to show. FIG. 2 shows the molar ratio of DMAH to the total number of moles of TMA and DMAH in the mixtures of Preparation Examples 1-7 and the total number of moles of TMA and DMAH in the vapor of the aluminum-containing composition of Preparation Examples 1-7. It is a graph which shows the correlation with the molar ratio of DMAH. FIG. 3 is a graph showing the correlation between the growth temperature and the growth film thickness per unit cycle in Examples 1 to 6 and Comparative Examples 1 to 6.

The method for producing an aluminum-containing oxide thin film according to the present invention is formed by atomic layer deposition (ALD) using an aluminum-containing composition as an aluminum source and an oxygen-containing compound as an oxygen source as raw materials. An aluminum-containing oxide thin film is formed on the object.
1. Aluminum-containing composition The aluminum-containing composition is an aluminum precursor, which is a mixture of trimethylaluminum and dimethylaluminum hydride.

  Trimethylaluminum can be produced, for example, by the method described in JP2009-263326A. Moreover, as trimethylaluminum, a commercial item can be used, for example, it can be purchased from Trichemical Laboratories, Japan Air Liquide, ADEKA, etc.

  The vapor pressure of trimethylaluminum (TMA) is shown in FIG.

  Dimethylaluminum hydride can be produced, for example, by the method described in JP-A No. 2000-72780. Moreover, as dimethylaluminum hydride, a commercial item can be used, for example, it can be purchased from Sigma-Aldrich.

  The vapor pressure of dimethylaluminum hydride (DMAH) is shown in FIG.

  In the aluminum-containing composition, the molar ratio of trimethylaluminum: dimethylaluminum hydride is, for example, 4: 6-8: 2, preferably 6: 4-7: 3, and more preferably 6.4: 3.6. 6.8: 3.2. In addition, the molar ratio in an aluminum containing composition can be measured by the method as described in the Example mentioned later.

  In addition, in the aluminum containing composition, the vapor pressure of the aluminum containing composition whose molar ratio of trimethylaluminum: dimethylaluminum hydride is 6.6: 3.4 is shown in FIG.

  That is, as shown in FIG. 1, an aluminum-containing composition (Al-containing composition) prepared by mixing trimethylaluminum and dimethylaluminum hydride has a higher vapor pressure than trimethylaluminum, and trimethylaluminum at each temperature: A constant vapor pressure is observed when the molar ratio of dimethylaluminum hydride is in the range of 4: 6 to 8: 2.

  The aluminum-containing composition is preferably composed of trimethylaluminum and dimethylaluminum hydride.

  It does not restrict | limit especially as a manufacturing method of such an aluminum containing composition, It can manufacture by a well-known manufacturing method.

  More specifically, first, trimethylaluminum, dimethylaluminum hydride, and, if necessary, a solvent are stirred and mixed to prepare a mixture.

  The blending ratio of dimethylaluminum hydride is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 40 parts by mass or more, for example, 200 parts by mass or less, preferably 100 parts by mass of trimethylaluminum. 150 parts by mass or less, more preferably 120 parts by mass or less, and particularly preferably 60 parts by mass or less.

  The solvent is not particularly limited as long as it is a reaction inert solvent with respect to trimethylaluminum and dimethylaluminum hydride, and examples thereof include known solvents such as hydrocarbons. Examples of the hydrocarbons include aliphatic saturated hydrocarbons (eg, heptane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, etc.), aromatic hydrocarbons (toluene, xylene, mesitylene). , Cumene, cymen, tetralin, etc.), liquid paraffin, mineral oil and the like.

  Among such solvents, liquid paraffin is preferable. Solvents can be used alone or in combination of two or more.

  The mixing ratio of the solvent is not particularly limited as long as it does not adversely affect the stirring.

  The mixing temperature is not particularly limited as long as it is not lower than the melting point and not higher than the decomposition temperature.

  Such a mixing step is preferably performed in an inert gas (for example, nitrogen gas, argon gas) atmosphere.

  Thus, a mixture containing trimethylaluminum and dimethylaluminum hydride is prepared.

  In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride is, for example, 3: 7 to 9: 1, preferably 4: 6 to 8: 2.

  The mixture is then purified by distillation.

  Examples of the distillation method include known distillation methods, and preferably include batch distillation and continuous distillation using a distillation column. Examples of the distillation tower include known distillation towers such as a packed tower and a plate tower.

2. Oxygen-containing compound The oxygen-containing compound is a compound containing an oxygen atom, and examples thereof include oxygen, ozone, nitrogen dioxide, water, hydrogen peroxide, formic acid, acetic acid, and acetic anhydride. Of the oxygen-containing compounds, water is preferable. The oxygen-containing compounds can be used alone or in combination of two or more.

3. Film Forming Method Next, an aluminum-containing oxide thin film is formed on the film formation object by an atomic layer deposition apparatus. In the present embodiment, the case where the aluminum-containing oxide thin film is an aluminum oxide thin film will be described in detail.

  The atomic layer deposition apparatus is a known atomic layer deposition apparatus (ALD apparatus), which includes a first raw material container that contains an aluminum-containing composition, a second raw material container that contains an oxygen-containing compound, and a first raw material container. A chamber (reaction chamber) capable of supplying an aluminum-containing composition and capable of supplying an oxygen-containing compound from a second raw material container.

  Such an atomic layer deposition apparatus may be a single wafer type apparatus or a batch type apparatus capable of simultaneously processing a large number of sheets. As a vaporization supply method of the atomic layer deposition apparatus, a baking method can be cited.

  Further, the film formation target is not particularly limited. Examples of the material of the film formation target include silicon, fine ceramics (for example, ceramics such as silicon nitride, titanium nitride, tantalum nitride, titanium oxide, titanium nitride, ruthenium oxide, zirconium oxide, hafnium oxide, lanthanum oxide), glass, and the like. , Metals (for example, ruthenium) and the like.

  In addition, examples of the shape of the film formation target include a plate shape, a spherical shape, a fiber shape, and a scale shape. The film formation surface of the film formation target may be a flat surface or may have a three-dimensional structure such as a trench structure. Among such film formation objects, a silicon wafer on which silicon is formed in a plate shape is preferable.

  In order to form an aluminum oxide thin film on a film formation object by the atomic layer deposition apparatus, first, the film formation object is placed in the chamber of the atomic layer deposition apparatus.

  Next, the temperature in the chamber of the atomic layer deposition apparatus is raised to the reaction temperature (growth temperature) and adjusted to a predetermined reaction pressure.

  The reaction temperature (growth temperature) is not particularly limited as long as the aluminum oxide thin film is formed. For example, the reaction temperature is 10 ° C. or higher, preferably 100 ° C. or higher, more preferably 150 ° C. or higher, for example 500 ° C or lower, preferably 400 ° C or lower, and more preferably 300 ° C or lower.

  If the reaction temperature (growth temperature) is not less than the above lower limit and not more than the upper limit, the growth film thickness per unit cycle described later can be reliably improved.

  The reaction pressure is, for example, 1 Pa or more, preferably 10 Pa or more, more preferably 100 Pa or more, for example 10,000 Pa or less, preferably 1000 Pa or less, more preferably 200 Pa or less. Note that the inside of the chamber of the atomic layer deposition apparatus is preferably replaced with an inert gas atmosphere. As an inert gas, helium, argon, nitrogen etc. are mentioned, for example, Preferably nitrogen is mentioned.

  Next, the vaporized aluminum-containing composition is supplied to the film formation target in a state where the inside of the chamber is maintained at the reaction temperature and the reaction pressure (first supply step).

  In the atomic layer deposition apparatus, the aluminum-containing composition may be vaporized in the first raw material container or in the chamber.

  The vaporization temperature (baking temperature) for vaporizing the aluminum-containing composition is, for example, 0 ° C. or higher, preferably 20 ° C. or higher, for example, 150 ° C. or lower, preferably 40 ° C. or lower.

  As a result, trimethylaluminum and dimethylaluminum hydride are adsorbed (deposited) on the surface of the film formation target (film formation surface) to form a single-layer precursor thin film.

  Next, excess (non-adsorbed) aluminum-containing composition gas or by-produced gas is exhausted from the chamber (first exhaust process).

  As an exhaust method, for example, an inert gas is supplied into the chamber and the inside of the chamber is purged, and the inside of the chamber is reduced to, for example, 0.01 Pa to 300 Pa, preferably 0.01 to 100 Pa. Examples include a method of exhausting the gas in the chamber, a method combining them, and the like. As such an exhausting method, preferably, an inert gas is supplied into the chamber and the inside of the chamber is purged.

  As an inert gas, the inert gas similar to the above is mentioned, for example, Preferably nitrogen is mentioned.

  The supply time of the inert gas is not particularly limited.

  In the first evacuation step, it is preferable to completely exhaust excess aluminum-containing composition gas or by-product gas from the chamber.

  In the first exhaust process, the temperature and pressure in the chamber are preferably maintained at the above reaction temperature and pressure.

  Next, an oxygen-containing compound is supplied to the precursor thin film while maintaining the inside of the chamber at the above reaction temperature and pressure (second supply step).

  When the oxygen-containing compound is liquid at room temperature, the oxygen-containing compound is supplied to the precursor thin film after being vaporized. In this case, the oxygen-containing compound may be vaporized in the second raw material container or vaporized in the chamber in the atomic layer deposition apparatus. The vaporization temperature for vaporizing the oxygen-containing compound is appropriately changed depending on the boiling point of the oxygen-containing compound.

  Thereby, the aluminum-containing composition comprising trimethylaluminum and dimethylaluminum hydride and the oxygen-containing compound react to form an aluminum oxide thin film.

  Next, excess (unreacted) oxygen-containing compound gas, generated gas, and the like are exhausted from the chamber by the exhaust method described above (second exhaust process).

  In the second evacuation step, it is preferable to completely exhaust excess oxygen-containing compound gas, generated gas, and the like from the chamber.

  In the second evacuation step, the temperature and pressure in the chamber are preferably maintained at the above reaction temperature and reaction pressure.

  Such a 1st supply process, a 1st exhaust process, a 2nd supply process, and a 2nd exhaust process are one reaction cycle.

  The growth thickness of the aluminum oxide thin film per reaction cycle (unit cycle) depends on the reaction temperature (growth temperature) of the vapor.

  The reaction cycle may be performed once, but is preferably performed a plurality of times from the viewpoint of adjusting the film thickness of the aluminum oxide thin film.

  When the reaction cycle is performed a plurality of times, the number of reaction cycles is, for example, 10 times or more, preferably 100 times or more, more preferably 200 times or more, for example, 1000 times or less, preferably 600 times or less, More preferably, it is 400 times or less.

  Thus, an aluminum oxide thin film having a predetermined film thickness is formed.

  Such aluminum oxide thin films include, for example, hard coating films for machine parts and tools, wiring materials for integrated circuits, gate insulating films for semiconductor memories, passivation films for solar cells, barrier films for organic electronics, and dielectrics for optical devices. It can be used for body films, electronic components such as MR heads for hard disks, optical glass such as circuits for optical communication, and catalysts.

  In addition, the film thickness of the aluminum oxide thin film is appropriately changed depending on the application.

4). Action Effect However, as a thin film forming method in the gas phase, in addition to the atomic layer deposition method, for example, a chemical vapor deposition (CVD) method is known. In the case where an aluminum-containing oxide thin film is formed by such a chemical vapor deposition method, an example of the aluminum source is trimethylaluminum. However, when trimethylaluminum is used as the aluminum source, carbon derived from the methyl group of trimethylaluminum remains in the aluminum-containing oxide thin film formed by the chemical vapor deposition method, and the film performance deteriorates. There is a problem that.

  Therefore, in order to reduce the residual carbon in the aluminum-containing oxide thin film, it is considered to use dimethylaluminum hydride having fewer methyl groups as an aluminum source than trimethylaluminum.

  However, dimethylaluminum hydride has a problem that its vapor pressure is lower and its viscosity is remarkably higher than that of trimethylaluminum. An aluminum-containing oxide thin film is obtained by chemical vapor deposition using dimethylaluminum hydride as a raw material (aluminum source). It has been difficult to produce the product efficiently.

  Therefore, an aluminum-containing composition that is a mixture of trimethylaluminum and dimethylaluminum hydride has been proposed as an aluminum source for vapor deposition for forming an aluminum-containing oxide thin film with low residual carbon. However, there is no report on thin film formation using an atomic layer deposition method using this aluminum-containing composition as an aluminum source, and there is no report on the use of aluminum-containing oxide thin films, especially aluminum oxide thin films.

  The chemical vapor deposition method and the atomic layer deposition method are different in film formation process, and it is said that the raw materials used in the chemical vapor deposition method cannot be used in the atomic layer deposition method in many cases. Moreover, it cannot be predicted whether the raw material used for the chemical vapor deposition method can be used for the atomic layer deposition method.

  Here, in the above method for producing an aluminum-containing oxide thin film, an aluminum-containing composition that is a mixture of trimethylaluminum and dimethylaluminum hydride is used as an aluminum source in the atomic layer deposition method.

  Compared to the case where an aluminum oxide thin film (aluminum-containing oxide thin film) is formed by the atomic layer deposition method using trimethylaluminum, which has been the only practical aluminum source for the atomic layer deposition method, By using an aluminum-containing composition, which is a mixture of trimethylaluminum and dimethylaluminum hydride, as the aluminum source, it is possible to improve the deposition rate of the aluminum oxide thin film and improve the productivity of the aluminum oxide thin film. . Therefore, such a method for producing an aluminum-containing oxide thin film can be suitably used as an industrial production method for an aluminum oxide thin film (aluminum-containing oxide thin film).

  In addition, since the number of moles of methyl groups contained in the aluminum-containing composition is reduced as compared with the case where the raw material is composed only of trimethylaluminum, the aluminum-containing oxide thin film formed by atomic layer deposition is used in the aluminum-containing oxide thin film. It is possible to suppress the carbon derived from the methyl group from remaining. Therefore, the film performance of the aluminum-containing oxide thin film can be improved.

  In the aluminum-containing composition, the molar ratio of trimethylaluminum: dimethylaluminum hydride is 4: 6 to 8: 2. Therefore, the composition ratio of trimethylaluminum and dimethylaluminum hydride in the vapor of the aluminum-containing composition has a constant value.

  As a result, when the film is formed by atomic layer deposition, the molar ratio of trimethylaluminum: dimethylaluminum hydride can be stably maintained at a single value even in the gas of the aluminum-containing composition. Therefore, the aluminum-containing oxide thin film can be stably formed.

  Moreover, since an aluminum containing oxide thin film is efficiently produced by said manufacturing method, the carbon which remains in an aluminum containing oxide thin film can be reduced, and the improvement of film | membrane performance can be aimed at.

  In addition, the aluminum-containing composition has a higher vapor pressure than that of dimethylaluminum hydride alone (see FIG. 1). Therefore, in the film formation of an aluminum-containing oxide thin film (aluminum oxide thin film), the aluminum-containing composition can be easily vaporized as compared with the case where dimethylaluminum hydride alone is a raw material. As a result, in forming an aluminum-containing oxide thin film (aluminum oxide thin film), the vaporization temperature for vaporizing the aluminum-containing composition can be reduced, and energy saving can be achieved.

  Further, the viscosity of the aluminum-containing composition is smaller than that of dimethylaluminum hydride alone. Therefore, the handleability of the aluminum-containing composition can be improved. Moreover, since an aluminum containing composition is stable compared with a dimethylaluminum hydride single-piece | unit, an aluminum containing composition can be stored stably.

5. Modification In addition, in said embodiment, the case where an aluminum containing oxide thin film is an aluminum oxide thin film is explained in full detail. However, the aluminum-containing oxide thin film is not limited to the aluminum oxide thin film.

  Examples of the aluminum-containing oxide thin film include an aluminum oxynitride thin film, an aluminum-containing composite oxide film represented by the following general formulas (1) to (4), in addition to the aluminum oxide thin film.

General formula (1): AlSixOy (1)
General formula (2): ZrAlxSiyOz (2)
General formula (3): TiAlxSiyOz (3)
General formula (4): HfAlxSiyOz (4)
In the general formulas (1) to (4), each of x, y, and z represents a numerical value, and the value is not particularly limited.

  In such a case, in the first supply step of the film formation method, a precursor corresponding to the target aluminum-containing oxide thin film is supplied to the film formation target together with the aluminum-containing composition.

  As a precursor, a well-known material is mentioned as a raw material of the target aluminum containing oxide thin film, for example.

  In such a case, the aluminum-containing composition and the precursor may be vaporized separately, or the aluminum-containing composition and the precursor can be vaporized after being mixed in advance according to a predetermined formulation.

  In the above-described method for forming an aluminum-containing oxide thin film, energy such as plasma, light, and voltage can be applied. The timing for applying these energies is not particularly limited, and may be any of the first supply process, the first exhaust process, the second supply process, and the second exhaust process, and between these processes. There may be.

  In addition, in the method for forming an aluminum-containing oxide thin film, in order to obtain better electrical characteristics after the formation of the aluminum-containing oxide thin film, an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere is used. An annealing treatment can also be performed.

  Further, in the above method for forming an aluminum-containing oxide thin film, when step filling is necessary, after the formation of the aluminum-containing oxide thin film, for example, 200 ° C. to 1000 ° C., preferably 250 ° C. to 500 ° C. And a reflow process can also be implemented.

  Also according to these modified examples, the same effects as those of the above-described embodiment can be obtained.

  In addition, each of said embodiment and modification can be combined suitably.

Preparation Examples, Examples and Comparative Examples are shown below to further illustrate the present invention, but the present invention is not limited to them. Specific numerical values such as blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and the corresponding blending ratio (content ratio) ), Physical property values, parameters, etc. The upper limit value (numerical value defined as “less than” or “less than”) or lower limit value (number defined as “greater than” or “exceeded”) may be substituted. it can.
[Preparation Example 1]
330.5 g of trimethylaluminum (manufactured by Albemarle, electrical material grade) and 182.0 g of dimethylaluminum hydride (including 13.8 g of tri-n-propylamine) (manufactured with reference to the method described in International Publication No. WO2014 / 56821) Then, 331.5 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.) was stirred and mixed at 60 ° C. for 0.5 hour in a nitrogen atmosphere to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum (TMA): dimethylaluminum hydride (DMAH) was 6.1: 3.9. Table 1 shows the formulation of the mixtures of Preparation Examples 1 to 7 and the molar ratio of TMA: DMAH.

  Subsequently, the mixture was distilled by a distillation tower to obtain 429.1 g of an aluminum-containing composition that was a mixture of trimethylaluminum and dimethylaluminum hydride. The pressure inside the tower was 10 kPa, and the top temperature was 56 ° C.

  Moreover, the aluminum atom concentration of the aluminum-containing composition was 40.2% by mass.

The aluminum atom concentration of the aluminum-containing composition was measured by a silver nitrate titration method.
[Preparation Example 2]
17.1 g of trimethylaluminum, 4.5 g of dimethylaluminum hydride (including tri-n-propylamine 0.4 g), and 262.7 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.) The mixture was stirred for an hour to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 7.7: 2.3.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 28.5 g of an aluminum-containing composition.
[Preparation Example 3]
A mixture is obtained by mixing 490.3 g of trimethylaluminum, 268.6 g of dimethylaluminum hydride (including 20.4 g of tri-n-propylamine), and 216.7 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.). It was. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 6.1: 3.9.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 633.8 g of an aluminum-containing composition.
[Preparation Example 4]
In a nitrogen atmosphere, 17.2 g of trimethylaluminum, 19.0 g of dimethylaluminum hydride (including tri-n-propylamine 1.4 g) and 250.7 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.) The mixture was stirred and mixed at 0 ° C. for 0.5 hour to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 4.4: 5.6.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 29.3 g of an aluminum-containing composition.
[Preparation Example 5]
In a nitrogen atmosphere, 15.9 g of trimethylaluminum, 20.1 g of dimethylaluminum hydride (including tri-n-propylamine 1.5 g), and 242.8 g of Daphne Oil KP-15 (Idemitsu Kosan Co., Ltd.) The mixture was stirred and mixed at 0 ° C. for 0.5 hour to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 4.1: 5.9.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 24.6 g of an aluminum-containing composition.
[Preparation Example 6]
In a nitrogen atmosphere, 15.1 g of trimethylaluminum, 21.3 g of dimethylaluminum hydride (including tri-n-propylamine 1.6 g) and 270.2 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.) The mixture was stirred and mixed at 0 ° C. for 0.5 hour to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 3.8: 6.2.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 27.2 g of an aluminum-containing composition.
[Preparation Example 7]
In a nitrogen atmosphere, 14.9 g of trimethylaluminum, 21.7 g of dimethylaluminum hydride (including tri-n-propylamine 1.6 g), and 265.4 g of Daphne Oil KP-15 (manufactured by Idemitsu Kosan Co., Ltd.) The mixture was stirred and mixed at 0 ° C. for 0.5 hour to obtain a mixture. In the mixture, the molar ratio of trimethylaluminum: dimethylaluminum hydride was 3.7: 6.3.

Thereafter, the mixture was separated and purified in the same manner as in Preparation Example 1 to obtain 29.2 g of an aluminum-containing composition.
[Example 1]
In a chamber of an atomic layer deposition apparatus (BENEQ, trade name: TFS-200), a silicon wafer (film formation target, manufactured by TPOSIL, trade name: FZ-SILICON-PV-FZ WAFER (4 "P1001-5 Note that the vapor deposition supply method of the atomic layer deposition apparatus was a baking method, and the baking temperature was room temperature.

  Thereafter, nitrogen gas was introduced into the chamber, the temperature in the chamber was increased to 158 ° C. (growth temperature), and the pressure was reduced to 0.15 kPa.

  Next, a gas (aluminum source) of the aluminum-containing composition of Preparation Example 1 was supplied to the silicon wafer for 150 milliseconds, and then purged (washed) with nitrogen gas for 280 milliseconds, followed by water vapor (oxygen-containing compound, oxygen Source) for 150 milliseconds and then purged (washed) with nitrogen gas for 420 milliseconds. Then, supply of gas of the aluminum-containing composition (first supply process), purge with nitrogen gas (first exhaust process), supply of water vapor (second supply process), and purge with nitrogen gas (second exhaust process) Was a single reaction cycle, and the reaction cycle was repeated 275 cycles.

  Thus, an aluminum oxide thin film was formed on the silicon wafer.

  The film composition of the aluminum oxide thin film was confirmed by an X-ray photoelectron spectrometer (manufactured by CRATOS, trade name: AXIS-NOVA).

The thickness of the aluminum oxide thin film was 35.1 nm. The film thickness of the aluminum oxide thin film was measured by an optical ellipsometer (manufactured by JA WOOLLAM, trade name: M-2000).
[Example 2]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the growth temperature was changed to 208 ° C. The aluminum oxide thin film had a thickness of 37.5 nm.
[Example 3]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the growth temperature was changed to 256 ° C. The thickness of the aluminum oxide thin film was 37.7 nm.
[Example 4]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the growth temperature was changed to 306 ° C. The aluminum oxide thin film had a thickness of 35.9 nm.
[Example 5]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the growth temperature was changed to 357 ° C. The thickness of the aluminum oxide thin film was 33.3 nm.
[Example 6]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the growth temperature was changed to 408 ° C. The aluminum oxide thin film had a thickness of 28.4 nm.
[Comparative Example 1]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 1 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum.

The thickness of the aluminum oxide thin film was 38.6 nm.
[Comparative Example 2]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 2 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum. The aluminum oxide thin film had a thickness of 40.0 nm.
[Comparative Example 3]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 3 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum. The aluminum oxide thin film had a thickness of 38.1 nm.
[Comparative Example 4]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 4 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum. The aluminum oxide thin film had a thickness of 35.7 nm.
[Comparative Example 5]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 5 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum. The thickness of the aluminum oxide thin film was 32.3 nm.
[Comparative Example 6]
An aluminum oxide thin film was formed on a silicon wafer in the same manner as in Example 6 except that the aluminum-containing composition in Preparation Example 1 was changed to trimethylaluminum. The aluminum oxide thin film had a thickness of 28.7 nm.
[Evaluation]
-Composition of aluminum-containing composition (molar ratio):
About the aluminum containing composition obtained in Preparation Examples 1-7, the molar ratio of trimethylaluminum (TMA): dimethylaluminum hydride (DMAH) was measured. The results are shown in Table 1.

  The molar ratio of TMA: DMAH in the aluminum-containing composition was obtained by analyzing the gas generated by hydrolyzing the aluminum-containing composition by gas chromatography (manufactured by GL Sciences, trade name: GC-323). The measured values of methane and hydrogen were converted.

  In the gas chromatograph, no peak derived from Daphne oil KP-15 was observed. That is, Daphne oil KP-15 was separated by distillation and was not contained in the aluminum-containing composition.

  Also, the molar ratio of DMAH to the total number of moles of trimethylaluminum (TMA) and dimethylaluminum hydride (DMAH) in the mixture, and the molar ratio of DMAH to the total number of moles of TMA and DMAH in the vapor of the aluminum-containing composition A graph showing the correlation is shown in FIG.

  In FIG. 2, in the aluminum-containing composition (mixture), when the molar ratio of trimethylaluminum: dimethylaluminum hydride is in the range of 4.1: 5.9 to 7.7: 2.3, the aluminum-containing composition As for the vapor composition of the product, it was confirmed that the molar ratio of trimethylaluminum: dimethylaluminum hydride was constant, more specifically, in the range of 6.5: 3.5 to 6.7: 3.3. .

  That is, in the aluminum-containing composition, when the molar ratio of trimethylaluminum: dimethylaluminum hydride is in the range of 6.5: 3.5 to 6.7: 3.3, the aluminum-containing composition was vaporized. In the gas, it was confirmed that the molar ratio of trimethylaluminum: dimethylaluminum hydride was constant.

・ Growth film thickness per unit cycle:
The growth film thickness per unit cycle (one reaction cycle) was calculated for each of the aluminum oxide thin films obtained in Examples 1 to 6 and the aluminum oxide thin films obtained in Comparative Examples 1 to 6. The results are shown in Table 2. A graph showing the correlation between the growth temperature and the growth film thickness per unit cycle is shown in FIG.

Claims (4)

  An aluminum-containing oxide film characterized by forming an aluminum-containing oxide thin film by atomic layer deposition using an aluminum-containing composition containing trimethylaluminum and dimethylaluminum hydride and an oxygen-containing compound containing oxygen atoms as raw materials. Method of manufacturing a thin film.   2. The method for producing an aluminum-containing oxide thin film according to claim 1, wherein in the aluminum-containing composition, a molar ratio of the trimethylaluminum to the dimethylaluminum hydride is 4: 6 to 8: 2.   The said aluminum containing oxide thin film is an aluminum oxide thin film, The manufacturing method of the aluminum containing oxide thin film of Claim 1 or 2 characterized by the above-mentioned.   The aluminum containing oxide thin film manufactured by the manufacturing method of the aluminum containing oxide thin film as described in any one of Claims 1-3.

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