JP2022068022A - Forming method, forming material, and novel compound - Google Patents

Abstract

To provide a method of forming a Ni-based material.SOLUTION: In a method of forming a Ni-based material, a compound represented by Ni[i-C3H7 NC(n-C3H7)N-i-C3H7]2 is transported from an ingredient container to a vaporizer, vaporized by the vaporizer, and transported to a chamber together with a carrier gas, so that the compound transported to the chamber reacts with one or more reactants selected from a group consisting of ammonia, hydrogen, water, oxygen, ozone and nitrous oxide so as to form a Ni-based material on a substrate.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a film forming technique.

Ni (metallic nickel (eg, membrane)) is used in the contact portion as nickel silicide in the field of semiconductors.
The Ni is a magnetic material. Therefore, the Ni is required in the field of MEMS (Micro Electro Mechanical Systems).
The Ni is used as a material for, for example, a next-generation memory (for example, MRAM).
The Ni has high corrosion resistance and is utilized as an optical reflective film.
The Ni is utilized as a catalyst.
The Ni is used as a material for batteries.
Nickel oxide is used in fields such as variable absorption of light and electrochromic display devices.

By the atomic layer controlled growth method (ALD method), a Ni-based film (for example, Ni film, nickel oxide film, etc.) is formed in a fine structure at a low temperature. In this case, for example, β-diketonath nickel complex and cyclopentadienyl nickel complex have been proposed as raw material.

Ni [i-C ₃ H ₇ NC (CH ₃ ) N-i-C ₃ H ₇ ] ₂ {bis (N, N'-diisopropylacetoamidinate) nickel} has been proposed (Non-Patent Document 1). ..

Nickel
η3-2-methylallyl N, N'-diisopropylacetamidinate has been proposed (Patent Document 1).

Booyong S. Lim, Antti Rahtu, Jin-Seong Park, and Roy G. Gordon, Inorganic Chemistry., 2003, 42, 7951-7958)

US2013 / 016861A1

When the β-diketonat nickel complex was used, it was difficult to form a film by the ALD method. The metallic nickel film could not be formed.

The cyclopentadienyl nickel complex has a high decomposition temperature. Therefore, there is a risk that C (carbon atom) may enter the inside of the film.

The β-diketonate metal complex (or the cyclopentadienyl metal complex) was difficult to react with a hydroxyl group (-OH) or an amino group (-NH ₂ ) on the surface of the substrate. Therefore, the compound was unsuitable for the ALD method.

The metal aminate complex had good reactivity with the hydroxyl group (-OH) and the amino group (-NH ₂ ) on the substrate. Therefore, the metal aminate complex was suitable for the ALD method.

The proposed bis (N, N'-diisopropylacetamide) nickel {Ni [i-C ₃ H ₇ NC (CH ₃ ) N-i-C ₃ H ₇ ] ₂ } is a solid (melting point: about 69 ° C.). )Met. The heated and melted vapor of the compound is transported to the film forming chamber. At this time, the pipe (steam transport pipe) had to be heated to 70 ° C. or higher (at least 69 ° C. or higher). If the pipe was not heated to the temperature, the compound would solidify and deposit in the pipe. The pipe was blocked. At the melting point (69 ° C.) as described above, there may not be much problem in film formation at the laboratory level (small scale). However, the problem becomes greater at the mass production level at the factory. For example, if there is a cold spot in the pipe, the compound solidifies at that spot. The piping is blocked. The production line stops. At the mass production level, many wafers are wasted because they have undergone a series of processes. The loss will be large. In recent semiconductor mass production factories, a large amount of raw material compounds are sent to the reaction chamber. A system called direct liquid injection is adopted. In this method, the raw material is directly fed into the vaporization chamber as a liquid. The compound (gas) vaporized in the vaporization chamber is sent to the film formation reaction chamber. The solid (melting point: 69 ° C.) becomes a liquid when heated to 70 ° C. or higher (at least 69 ° C. or higher). This required a lot of heat energy. There was also concern about solidification blockage in the piping. It is also conceivable to heat the entire room in which the equipment is placed to a high temperature. However, raising the room temperature (overall) to 69 ° C or higher consumes a large amount of energy. The cost will be high. Workability is poor. High-purity products are required for semiconductor factories. Distillation is indispensable to obtain high-purity products. A sublimation method was used to purify the solid (melting point: 69 ° C.). However, high-purity products could not be obtained by sublimation purification.

The metal aminate complex has good reactivity with the hydroxyl group (-OH) and amino group (-NH ₂ ) on the substrate. Therefore, the aminated complex of the metal is suitable for the ALD method. The metal aminate complex chemically adsorbed on the substrate (hydroxyl group (-OH) or amino group (-NH ₂ ) on the surface of the substrate) reacts with water (or ammonia). A reactive end is formed with the metal aminate complex introduced in the next cycle. For example, if one of the organic groups coordinating to the metal is an aminate group and all of the remaining organic groups coordinating to the metal are other than the amidinate group, the amidinate group of the metal complex supplied in the first cycle will be. It reacts with a hydroxyl group (-OH) or an amino group (-NH ₂ ) on the substrate. However, the metal complex chemically adsorbed on -OH (or -NH ₂ ) no longer has an aminate group that can react in the next step. Therefore, it cannot react with the next supplied water or ammonia. That is, no end group capable of reacting with the metal complex introduced in the next cycle is formed. Therefore, ALD does not progress. The compound of Patent Document 1 was a compound of this kind. Therefore, when the compound of Patent Document 1 is used, ALD cannot be used. When the compound of Patent Document 1 is used, the plasma method must be used. However, ammonia plasma (hydrogen plasma) destroys the intermediate structure of the compound (compound of Patent Document 1) chemically adsorbed on the substrate. As a result, C and N may be mixed in the film. Therefore, it was found that it is desirable that all metal ligands (organic groups) are amidate groups.

For the above reasons, when the ALD method is used for film formation, a liquid Ni-aminated complex (even if it is a solid, having a melting point of about 35 ° C. to 40 ° C.) may be desired as a raw material compound. You can understand. That is, when transporting the raw material compound from the raw material container to the film forming chamber, a Ni-aminated complex that does not require high-temperature heating in the path (piping) (even if heating is necessary, the heating temperature is 40 ° C. or lower) is desired. You can understand what it is. For example, it will be understood that a liquid (or solid with a melting point of 40 ° C. or lower) Ni-aminated complex at 25 ° C. (1 atm) will be desired.

It can also be understood that a high-purity product of the Ni-aminated complex satisfying the above conditions can be easily obtained by a distillation operation.

However, a Ni aminate complex (all ligands are an aminate group) satisfying the above conditions has not been proposed so far. In the first place, it is not known what kind of structure the Ni aminate complex is a liquid (or a solid having a melting point of 40 ° C. or lower) at 25 ° C. (1 atm).

Therefore, the present invention is to solve the above-mentioned problems.
For example, it is to provide a technique capable of easily providing a high quality Ni material (for example, a film). For example, providing a Ni aminate complex that is liquid at 40 ° C.

Examinations and researches to solve the above-mentioned problems have been enthusiastically promoted.
As a result, the new compound {Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ } synthesized this time had a melting point of about 33 ° C.
The compound was easily obtained as a high-purity product by a distillation operation.
When the above compound was used and the film was formed by the ALD method, a high quality film was obtained.

The present invention has been achieved based on such findings.

The present invention
We propose a novel compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ .

The present invention
It is a material for forming Ni-based materials.
We propose a Ni-based material forming material having a compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ .

The present invention
It is a method of forming Ni-based materials.
The compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ is transported to the chamber, and the compound is transported to the chamber.
The compound transported to the chamber reacts with one or more reactants selected from the group of ammonia, hydrogen, water, oxygen, ozone and nitrous oxide.
We propose a method for forming Ni-based materials on a substrate.

The present invention
It is a method of forming Ni-based materials.
The compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) NI-C ₃ H ₇ ] ₂ is transported from the raw material container to the vaporizer and vaporized by the vaporizer to carry the carrier. Transported to the room with gas
The compound transported to the chamber reacts with one or more reactants selected from the group of ammonia, hydrogen, water, oxygen, ozone and nitrous oxide.
We propose a method for forming Ni-based materials on a substrate.

The present invention is the above-mentioned method, from the raw material container of the compound represented by the above-mentioned Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ to the vaporizer. We propose a method in which the transportation route is heated to a temperature of 30 to 40 ° C.

The present invention proposes the above method performed by the ALD method.

The compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ has a melting point of about 32 to 33 ° C. Therefore, the heating energy of the transportation route (piping) from the raw material container to the vaporizer can be reduced. There is no major problem in adopting the system used in semiconductor mass production factories, that is, direct liquid injection. The film formation cost is low. Since the compound is a liquid at 35 ° C to 40 ° C, a high-purity product can be easily obtained by a distillation operation. By the ALD method, high quality material was obtained at low cost. Good film formation efficiency. For example, a high-quality metallic Ni film (Ni alloy film) was efficiently formed.

Schematic diagram of ALD device Schematic diagram of ALD device

The first invention is a novel compound. The compound is a compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ . The compound is represented by the following [Formula 1]. In the compound (Ni amidinate complex), all the ligands were aminate groups. The compound had a melting point of 32 to 33 ° C. A high-purity product of the compound was easily obtained by a distillation operation. The vapor pressure (90 ° C.) of Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ was 0.5 Torr. The gas saturation method was used for the measurement of the vapor pressure. Since the vapor pressure is high, it was easy to form a film by the ALD method.

[Equation 1]

The second invention is a forming material. It is a material for forming a Ni-based material. For example, a Ni metal film. For example, a Ni oxide film. It is not limited to the above-mentioned substances. The material is not limited to a film. It may be thicker than the concept of membrane. The material has the compound Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ ). When the compound was used, a high quality film was efficiently obtained by the ALD method.

The third invention is a method. The method is a method for forming a Ni-based material. In the method, the compound {Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) NI-C ₃ H ₇ ] ₂ } is transported to the film forming chamber, and the transported compound ( This is a method in which the Ni-based material is provided on the substrate by reacting the complex) on the substrate. For example, the compound is transported to a chamber, and the compound transported to the chamber is one or more reactants selected from the group of reactants (ammonia, hydrogen, water, oxygen, ozone, nitrous oxide). ), And the Ni-based material is provided on the substrate. For example, the compound is transported from a raw material container to a vaporizer, vaporized by the vaporizer and transported to a chamber together with a carrier gas, and the compound transported to the chamber is a reactant (ammonia, hydrogen, water, oxygen, ozone). , One or more reactants selected from the group of nitrous oxide) to form a Ni-based material on the substrate. The reactant is transported to the chamber separately from the compound (eg, by another route or at different times). The transportation route (piping) from the raw material container of the compound to the vaporizer is heated to a temperature of, for example, 30 to 40 ° C. (about 33 ° C. or higher, for example, about 35 ° C.). The method comprises, for example, a step of transporting the compound to a chamber. The method comprises a step of providing the Ni-based material on the substrate by the reaction of the compound transported to the chamber. The ALD method is adopted as the method. The chamber is, for example, a film forming chamber (also referred to as a reaction chamber).

The Ni-based material (for example, a film) obtained as described above had an extremely small amount of C (impurity component). That is, the purity was high.

In the film forming process, it was difficult for trouble to occur. For example, film formation was performed by vaporization / reaction of the compound (raw material (X (g)). After 0.7 · X (g) of the raw material was consumed, the film formation work was stopped. The inside of the pipe connecting the raw material container and the film forming chamber was observed. No blockage inside the pipe (blockage due to solidification of the raw material) was observed.

Specific examples are given below. However, the present invention is not limited to the following examples. Various modifications and applications are also included in the present invention as long as the features of the present invention are not significantly impaired.

[Example 1]
[Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ : Bis (N, N'-diisopropylbutane amidate) nickel]
The reaction was carried out in an atmosphere of an inert gas. 0.29 mol of N, N'-diisopropylcarbodiimide was slowly added dropwise to 250 ml of a diethyl ether solution containing 0.28 mol of normal propyl lithium. After that, stirring was performed at room temperature for 4 hours. This reaction mixture was gradually added dropwise to a solution in which 0.12 mol of nickel dimethoxyethane chloride adduct (NiCl ₂ · DME) was suspended in 100 ml of tetrahydrofuran. After this, stirring was performed for 24 hours. After distilling off the solvent, 500 ml of normal hexane was added. The insoluble material was filtered. After distilling off the solvent, distillation under reduced pressure (0.1 torr) was performed. Bis (N, N'-diisopropylbutaneaminated) nickel was obtained in 80% yield.

The obtained compound was distilled under reduced pressure (purification). The vaporized bis (N, N'-diisopropylbutaneaminated) nickel (steam) was liquefied while passing through the air-cooled tube and collected in the receiver. At this time, the air-cooled pipe was heated to 35 ° C to 40 ° C. The recovery rate was 98%.

The refined product (bis (N, N'-diisopropylbutaneamidinate) nickel) was crystallized by cooling. The crystallized compound was gradually warmed. It melted at 32 ° C to 33 ° C. The boiling point was 92 ° C. in vacuum distillation using an oil rotary vacuum pump.

The purity of the refined product was high. The analytical values (unit: wt.ppm) by metal impurity analysis (ICP-MS) were as follows. Na <0.1, Mg <0.1, Fe = 0.4, Zn = 0.3, Ti <0.1, Cu = 0.1, Cd <0.1, Mn <0.1, Co = 0.1, Pb <0.1

[Example 2]
The film forming operation was performed using the film forming device of FIG. 1. FIG. 1 is a schematic view of a film forming apparatus. In FIG. 1, reference numeral 1 is a raw material container. Reference numeral 2 is a substrate heater (holding and heating the substrate). Reference numeral 3 is a film forming chamber (decomposition reaction furnace). Reference numeral 4 is a substrate. Reference numeral 5 is a flow rate controller. 6 is a shower head. Reference numeral 7 is a carrier gas (an inert gas such as Ar or _N2 ). Reference numeral 10 is an additive gas (for example, an inert gas such as Ar and N ₂ and a reducing gas such as H ₂ and NH ₃ ) introduced into the film forming chamber 3 at the time of film formation.

The film formation work was performed using the apparatus shown in FIG. The refined product (the Ni-aminated complex) was placed in the raw material container 1. The raw material container 1 was heated to 80 ° C. by a heater attached to the raw material container 1. Nitrogen gas (carrier gas) was supplied at a rate of 20 ml / min. Bubbling was done. As a result, the compound (the Ni aminate complex) was guided into the film forming chamber 3 together with nitrogen gas for 5 seconds. The inside of the film forming chamber 3 was exhausted by the pump for 12 seconds. A predetermined amount of the added gas (Ar gas 40 sccm, NH ₃ gas 20 sccm, H ₂ gas 80 sccm) 10 was supplied into the film forming chamber 3 for 5 seconds. The inside of the film forming chamber 3 was exhausted by the pump for 12 seconds. Again, the compound was introduced into the film forming chamber 3 together with nitrogen gas for 5 seconds. This cycle was repeated 100 times. The substrate 4 is heated (200 to 250 ° C.) by the substrate heater 2. A film (metal Ni thin film) was formed on the substrate 4.

The film formed as described above was uniformly applied to the inner wall of the hole (opening 100 nm, depth 1 μm). Excellent step coverage. The membrane was examined by XPS. The amount of C in the membrane was 2 at% or less. The amount of N in the membrane was 1 at% or less.

[Example 3]
The film forming operation was performed using the film forming device of FIG. FIG. 2 is a schematic view of the film forming apparatus. In FIG. 2, reference numeral 1 is a raw material container. Reference numeral 2 is a substrate heater. Reference numeral 3 is a film forming chamber (decomposition reaction furnace). Reference numeral 4 is a substrate. Reference numeral 5 is a flow rate controller. 6 is a shower head. 8 is a vaporizer. Reference numeral 9 is a gas for pumping the raw material (for example, an inert gas such as He or Ar. The raw material is pumped from the raw material container 1 to the vaporizer 8). Reference numeral 10 is an additive gas (for example, an inert gas such as Ar and N ₂ and a reducing gas such as H ₂ and NH ₃ ) introduced into the film forming chamber 3 at the time of film formation. Reference numeral 11 is a pressure controller for the raw material pressure feeding gas 9. Reference numeral 12 is a liquid flow rate controller (controlling the pressure feeding flow rate of the raw material liquid to the vaporizer 8).

The film formation work was performed using the apparatus shown in FIG. The refined product (the Ni-aminated complex) was placed in the raw material container 1. It was heated to 35 ° C to 40 ° C. _N2 gas was used as the raw material pumping gas 9. The pressure was adjusted to 0.1 MPa by the pressure controller 11. The compound (aminated complex) was pumped (the pumping amount was adjusted to 0.1 mg / min) by the liquid flow rate controller 12. The compound was fed into the vaporizer 8. The pipe in which the compound was transported to the vaporizer 8 was heated to 35 ° C to 40 ° C. The compound sent to the vaporizer 8 was guided into the film forming chamber 3 together with 50 sccm of Ar gas (carrier gas) for 5 seconds. The inside of the film forming chamber 3 was exhausted by the pump for 12 seconds. A predetermined amount of added gas (Ar gas 40 sccm, NH ₃ gas 20 sccm, H ₂ gas 80 sccm) 10 was supplied into the film forming chamber 3 for 2 seconds. The inside of the film forming chamber 3 was exhausted by the pump for 12 seconds. Again, the compound was guided into the film forming chamber 3 together with the carrier gas for 5 seconds. This cycle was repeated 100 times. The pipe from the raw material container 1 to the vaporizer through which the compound was transported was heated to 35 ° C to 40 ° C. The substrate 4 is heated (200 to 250 ° C.) by the substrate heater 2. A film (metal Ni thin film) was formed on the substrate 4.

The film formed as described above was excellent in in-plane uniformity. The membrane was examined by XPS. The amount of C in the membrane was 2 at% or less. The amount of N in the membrane was 1 at% or less.

1 Raw material container 2 Substrate heater 3 Film formation chamber 4 Substrate 5 Flow controller 6 Shower head 7 Carrier gas 8 Vaporizer 9 Raw material pressure feed gas 10 Raw material pressure feed gas 11 Raw material pressure feed gas pressure controller 12 Liquid flow rate controller

Claims (5)

It is a method of forming Ni-based materials.
The compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ is transported to the chamber, and the compound is transported to the chamber.
The compound transported to the chamber reacts with one or more reactants selected from the group of ammonia, hydrogen, water, oxygen, ozone and nitrous oxide.
A method of forming a Ni-based material on a substrate. It is a method of forming Ni-based materials.
The compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) NI-C ₃ H ₇ ] ₂ is transported from the raw material container to the vaporizer and vaporized by the vaporizer to carry the carrier. Transported to the room with gas
The compound transported to the chamber reacts with one or more reactants selected from the group of ammonia, hydrogen, water, oxygen, ozone and nitrous oxide.
A method of forming a Ni-based material on a substrate. The temperature of the transport route from the raw material container of the compound represented by Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] ₂ to the vaporizer is 30 to 40 ° C. The method of claim 1 or claim 2 which is heated to. It is a material for forming Ni-based materials.
Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] A Ni-based material forming material having a compound represented by ₂ . Ni [i-C ₃ H ₇ NC (n-C ₃ H ₇ ) N-i-C ₃ H ₇ ] A novel compound represented by ₂ .

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