Patent Application
20200277512
The present invention relates to a composition for film deposition and a film deposition apparatus.
In a film deposition process such as vapor deposition polymerization, a molecule supplied with gas is adsorbed on a substrate and polymerized by thermal energy of the substrate, and a thin film of polymer is formed. Patent Document 1 discloses a film deposition method of forming a polyimide film by supplying a first processing gas that includes a first monomer and a second processing gas that includes a second monomer to a substrate, and performing vapor deposition and polymerization of the first monomer and the second monomer on a surface of a wafer.
Crystallization in a film may occur in a polymer film formed by a film deposition process. Such crystallization may reduce the uniformity of a film (hereinafter referred to as film roughness) and cause structural defects.
It is an object of the present invention to provide a composition for film deposition that can suppress the occurrence of crystallization in a film.
In order to achieve the object described above, one aspect of the present invention provides a composition for film deposition that includes a first component that polymerizes with a second component to form a nitrogen-containing carbonyl compound, and wherein the molecular structure of the first component and the molecular structure of the second component are asymmetric with each other.
According to one aspect of the present invention, the occurrence of crystallization in a film can be suppressed.
In the following, an embodiment of the present invention will be described in detail.
<Composition for Film Deposition>
A composition for film deposition according to the embodiment of the present invention includes a first component that polymerizes with a second component to form a nitrogen-containing carbonyl compound, and wherein a molecular structure of the first component and a molecular structure of the second component are asymmetric with each other.
<Nitrogen-Containing Carbonyl Compound>
In the composition for film deposition according to the embodiment, the nitrogen-containing carbonyl compound formed by polymerization of the first component and the second component is a polymer containing a carbon-oxygen double bond and nitrogen. The nitrogen-containing carbonyl compound constitutes a component of a film deposited by polymerization of the first component and the second component. The nitrogen-containing carbonyl compound can be, for example, a protective film for preventing a specific portion of a wafer from being etched, as a polymer film.
The nitrogen-containing carbonyl compound is not particularly limited. With respect to the stability of a formed film, examples of the nitrogen-containing carbonyl compound include polyureas, polyurethanes, polyamides, and polyimides. These nitrogen-containing carbonyl compounds may be used either singly or in combinations of two or more compounds. In the embodiment, among these nitrogen-containing carbonyl compounds, polyureas and polyimides are preferable, and polyureas are more preferable. Here, these nitrogen-containing carbonyl compounds are examples of the nitrogen-containing carbonyl compound in the composition for film deposition according to the subject matter of this application.
<First Component>
The first component included in the composition for film deposition according to the embodiment is a monomer that can polymerize with the second component to form the nitrogen-containing carbonyl compound. Compounds suitable as a first component are not particularly limited, but includes, for example, isocyanates, amines, acid anhydrides, carboxylic acids, and alcohols. These compounds are examples of suitable first components to be included in the composition for film deposition according to the subject matter of this application.
Isocyanates, which are examples of the first component, are a chemical species that can polymerize with amines to form polyureas and can polymerize with alcohols to form polyurethanes. The number of carbon atoms of the isocyanate is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, 2 to 12 more preferably, and 2 to 8 still more preferably.
Additionally, the structure of the isocyanate is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Isocyanates including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the isocyanate is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the isocyanate is preferably a monofunctional compound or a bifunctional compound.
Specific examples of suitable isocyanates include 4,4′-diphenylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,3-bis(isocyanatomethyl)benzene, paraphenylene diisocyanate (PPDI), 4,4′-methylene diisocyanate, benzyl isocyanate, 1,2-diisocyanatoethane, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,10-diisocyanatodecane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1,2-diisocyanatopropane, 1,1-diisocyanatoethane, 1,3,5-triisocyanatobenzene, 1,3-bis(isocyanato-2-propyl)benzene, isophorone diisocyanate, and 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane. The above-described isocyanate compounds may be used either singly or in combinations of two or more compounds.
Amines, which are examples of the first component, are a chemical species that can polymerize with isocyanates to form polyureas, and also can polymerize with acid anhydrides to form polyimides. The number of carbon atoms of the amine is not particularly limited, but with respect to obtaining a sufficient deposition rate, the number of carbon atoms is preferably 2 to 18, more preferably 2 to 12, and still more preferably 4 to 12.
Additionally, the structure of the amine is not particularly limited, and, for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Amines including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the amine is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the amine is preferably a monofunctional or bifunctional compound.
Specific examples of suitable amines include 1,3-bis(aminomethyl)cyclohexane (H6XDA), 1,3-bis(aminomethyl)benzene, paraxylylenediamine, 1,3-phenylenediamine (MPDA), paraphenylenediamine (PPDA), 4,4′-methylenedianiline (MDA), 3-(aminomethyl)benzylamine (MXDA), hexamethylenediamine(HMDA), benzylamine, 1,2-diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecan, 1,12-diaminododecan (DDA), 2-aminomethyl-1,3-propanediamine, methanetriamine, bicyclo[2.2.1]heptanedimethaneamine, piperazine, 2-methylpiperazine, 1,3-di-4-piperidylpropane, 1,4-diazepane, diethylenetriamine, N-(2-aminoethyl)-N-methyl-1,2-ethanediamine, bis(3-aminopropyl)amine, triethylenetetramine, and spermidine. The above-described amine compounds may be used either singly or in combinations of two or more compounds.
Acid anhydrides, which are examples of the first component, are a chemical species that can polymerize with amines to form polyimides. The number of carbon atoms of the acid anhydride is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, more preferably 2 to 12, and still more preferably 4 to 12.
The structure of the acid anhydride is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Acid anhydrides including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the acid anhydride is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the acid anhydride is preferably a monofunctional or bifunctional compound.
Specific examples of suitable acid anhydrides include pyromellitic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, 2,2′,3,3′-benzophenone tetracarboxylic dianhydride, 2,3,3′,4′-benzophenone tetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,4,5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, naphthalene-1,2,6,7-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,4,5,8-tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 3,3″,4,4″-p-terphenyltetracarboxylic dianhydride, 2,2″,3,3″-p-terphenyltetracarboxylic dianhydride, 2,3,3″,4″-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, perylene-2,3,8,9-tetracarboxylic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride, phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, and 2,3,6,7-naphthalenetetracarboxylic dianhydride. The above-described acid anhydride compounds may be used either singly or in combinations of two or more compounds.
Carboxylic acids, which are examples of the first component, are a chemical species that can polymerize with amines to form polyamides. The number of carbon atoms of the carboxylic acid is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, is 2 to 12 more preferably, and is 2 to 8 still more preferably.
The structure of the carboxylic acid is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like may be employed. Carboxylic acids including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the carboxylic acid is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the carboxylic acid is preferably a monofunctional or bifunctional compound.
Specific examples of suitable carboxylic acids include butanedioic acid, pentanedioic acid, hexanedioic acid, octanedioic acid, 2,2′-(1,4-cyclohexanediyl)diacetic acid, 1,4-phenylenediacetic acid, 4,4′-methylenedibenzoic acid, phenyleneacetic acid, benzoic acid, salicylic acid, acetylsalicylic acid, succinyl chloride, glutaryl chloride, adipoyl chloride, suberoyl chloride, 2,2′-(1,4-phenylene) diacetyl chloride, terephthaloyl chloride, and phenylacetyl chloride. The above-described carboxylic acid compounds may be used either singly or in combinations of two or more compounds.
Alcohols, which are examples of the first component, are a chemical species that can polymerize with isocyanates to form polyurethanes. The number of carbon atoms of the alcohol is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, is more preferably 2 to 12, and is still more preferably 4 to 12.
The structure of the alcohol is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Alcohols including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the alcohol is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the alcohol is preferably a monofunctional or bifunctional compound.
Specific examples of suitable alcohols include 1,3-cyclohexanediyldimethanol, 1,3-phenylenedimethanol, hydroquinone, benzyl alcohol, 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2,5-norbonandiol, methantriol, diethylene glycol, triethylene glycol, and 3,3′-oxydipropane-1-ol. The above-described alcohol compounds may be used either singly or in combinations of two or more compounds.
The desorption energy of the first component is the activation energy needed to remove the first component from an interface, and is expressed in the unit of kJ/mol. The range of the desorption energy of the first component is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the range of the desorption energy of the first component is preferably 10 to 130 kJ/mol, is more preferably 30 to 120 kJ/mol, and is still more preferably 50 to 110 kJ/mol. If a minimum value of the range of the desorption energy is too low, the first component that does not contribute to polymerization is also adsorbed, and the purity of a formed polymer may be reduced. If a maximum value of the range of the desorption energy is too high, there is a possibility that a film of the nitrogen-containing carbonyl compound cannot be sufficiently formed or the uniformity of a formed film is reduced.
Another physical property of the first component is not particularly limited. To maintain adsorption of the first component, a boiling point of the first component is preferably 100° C. to 500° C. Specifically, the boiling point of the first component is 100° C. to 450° C. for amines, is 100° C. to 450° C. for isocyanates, is 120 to 500° C. for carboxylic acids, is 150° C. to 500° C. for acid anhydrides, and is 150° C. to 400° C. for alcohols.
<Second Component>
The second component included in the composition for film deposition according to the embodiment is a monomer that can polymerize with the first component to form the nitrogen-containing carbonyl compound. Compounds suitable as a second component are not particularly limited, but includes, for example, isocyanates, amines, acid anhydrides, carboxylic acids, and alcohols. These compounds are examples of suitable second components to be included in the composition for film deposition according to the subject matter of this application.
Isocyanates, which are examples of the second component, are a chemical species that can polymerize with amines to form polyureas and can polymerize with alcohols to form polyurethanes. The number of carbon atoms of the isocyanate is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, 2 to 12 more preferably, and 2 to 8 still more preferably.
Additionally, the structure of the isocyanate is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Isocyanates including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the isocyanate is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the isocyanate is preferably a monofunctional compound or a bifunctional compound.
Specific examples of suitable isocyanates include 4,4′-diphenylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,3-bis(isocyanatomethyl)benzene, paraphenylene diisocyanate (PPDI), 4,4′-methylene diisocyanate, benzyl isocyanate, 1,2-diisocyanatoethane, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,10-diisocyanatodecane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1,2-diisocyanatopropane, 1,1-diisocyanatoethane, 1,3,5-triisocyanatobenzene, 1,3-bis(isocyanato-2-propyl)benzene, isophorone diisocyanate, and 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane. The above-described isocyanate compounds may be used either singly or in combinations of two or more compounds.
Amines, which are examples of the second component, are a chemical species that can polymerize with isocyanates to form polyureas, and also can polymerize with acid anhydrides to form polyimides. The number of carbon atoms of the amine is not particularly limited, but with respect to obtaining a sufficient deposition rate, the number of carbon atoms is preferably 2 to 18, more preferably 2 to 12, and still more preferably 4 to 12.
Additionally, the structure of the amine is not particularly limited, and, for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Amines including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the amine is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the amine is preferably a monofunctional or bifunctional compound.
Specific examples of suitable amines include 1,3-bis(aminomethyl)cyclohexane (H6XDA), 1,3-bis(aminomethyl)benzene, paraxylylenediamine, 1,3-phenylenediamine (MPDA), paraphenylenediamine (PPDA), 4,4′-methylenedianiline (MDA), 3-(aminomethyl)benzylamine (MXDA), hexamethylenediamine (HMDA), benzylamine, 1,2-diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecan, 1,12-diaminododecan (DDA), 2-aminomethyl-1,3-propanediamine, methanetriamine, bicyclo[2.2.1]heptanedimethaneamine, piperazine, 2-methylpiperazine, 1,3-di-4-piperidylpropane, 1,4-diazepane, diethylenetriamine, N-(2-aminoethyl)-N-methyl-1,2-ethanediamine, bis(3-aminopropyl)amine, triethylenetetramine, and spermidine. The above-described amine compounds may be used either singly or in combinations of two or more compounds.
Acid anhydrides, which are examples of the second component, are a chemical species that can polymerize with amines to form polyimides. The number of carbon atoms of the acid anhydride is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, more preferably 2 to 12, and still more preferably 4 to 12.
The structure of the acid anhydride is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Acid anhydrides including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the acid anhydride is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the acid anhydride is preferably a monofunctional or bifunctional compound.
Specific examples of suitable acid anhydrides include pyromellitic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, 2,2′,3,3′-benzophenone tetracarboxylic dianhydride, 2,3,3′,4′-benzophenone tetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,4,5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, naphthalene-1,2,6,7-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,4,5,8-tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 3,3″,4,4″-p-terphenyltetracarboxylic dianhydride, 2,2″,3,3″-p-terphenyltetracarboxylic dianhydride, 2,3,3″,4″-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl) ethane dianhydride, perylene-2,3,8,9-tetracarboxylic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride, phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, and 2,3,6,7-naphthalenetetracarboxylic dianhydride. The above-described acid anhydride compounds may be used either singly or in combinations of two or more compounds.
Carboxylic acids, which are examples of the second component, are a chemical species that can polymerize with amines to form polyamides. The number of carbon atoms of the carboxylic acid is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, is 2 to 12 more preferably, and is 2 to 8 still more preferably.
The structure of the carboxylic acid is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like may be employed. Carboxylic acids including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the carboxylic acid is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the carboxylic acid is preferably a monofunctional or bifunctional compound.
Specific examples of suitable carboxylic acids include butanedioic acid, pentanedioic acid, hexanedioic acid, octanedioic acid, 2,2′-(1,4-cyclohexanediyl)diacetic acid, 1,4-phenylenediacetic acid, 4,4′-methylenedibenzoic acid, phenyleneacetic acid, benzoic acid, salicylic acid, acetylsalicylic acid, succinyl chloride, glutaryl chloride, adipoyl chloride, suberoyl chloride, 2,2′-(1,4-phenylene)diacetyl chloride, terephthaloyl chloride, and phenylacetyl chloride. The above-described carboxylic acid compounds may be used either singly or in combinations of two or more compounds.
Alcohols, which are examples of the second component, are a chemical species that can polymerize with isocyanates to form polyurethanes. The number of carbon atoms of the alcohol is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the number of carbon atoms is preferably 2 to 18, is more preferably 2 to 12, and is still more preferably 4 to 12.
The structure of the alcohol is not particularly limited, and for example, a basic structure of an aromatic compound, a xylene-based compound, an alicyclic compound, an aliphatic compound, and the like can be employed. Alcohols including such a basic structure may be used either singly or in combinations of two or more compounds.
The functionality of the alcohol is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the alcohol is preferably a monofunctional or bifunctional compound.
Specific examples of suitable alcohols include 1,3-cyclohexanediyldimethanol, 1,3-phenylenedimethanol, hydroquinone, benzyl alcohol, 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2,5-norbonandiol, methantriol, diethylene glycol, triethylene glycol, and 3,3′-oxydipropane-1-ol. The above-described alcohol compounds may be used either singly or in combinations of two or more compounds.
The desorption energy of the second component is the activation energy needed to remove the second component from an interface, and is expressed in the unit of kJ/mol. The range of the desorption energy of the second component is not particularly limited, but with respect to obtaining a sufficient film deposition rate, the range of the desorption energy of the second component is preferably 10 to 130 kJ/mol, is more preferably 30 to 120 kJ/mol, and is still more preferably 50 to 110 kJ/mol. If a minimum value of the range of the desorption energy is too low, the second component that does not contribute to polymerization is also adsorbed, and the purity of a formed polymer may be reduced. If a maximum value of the range of the desorption energy is too high, there is a possibility that a film of the nitrogen-containing carbonyl compound cannot be sufficiently formed or the uniformity of a formed film is reduced.
Another physical property of the second component is not particularly limited. To maintain adsorption of the second component, a boiling point of the second component is preferably 100° C. to 500° C. Specifically, the boiling point of the second component is 100° C. to 450° C. for amines, is 100° C. to 450° C. for isocyanate, is 120° C. to 500° C. for carboxylic acids, is 150° C. to 500° C. for acid anhydrides, and is 150° C. to 400° C. for an alcohols.
The combination of the first component and the second component is not particularly limited, but either the first component or the second component is preferably isocyanate, and the isocyanate is more preferably a bifunctional alicyclic compound. Still more preferably, the bifunctional alicyclic compound is 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI).
Additionally, the other component of the first component or the second component is preferably amine, and the amine is more preferably a bifunctional alicyclic compound. Still more preferably, the bifunctional alicyclic compound is 1,3-bis(aminomethyl)cyclohexane (H6XDA).
A method of polymerizing the first component and the second component is not particularly limited as long as a nitrogen-containing carbonyl compound can be formed. However, with respect to obtaining a sufficient film deposition rate, a vapor deposition polymerization method is preferred. The vapor deposition polymerization method is a method of polymerization in which two or more monomers are simultaneously heated and evaporated in a vacuum so that the monomers are polymerized on a substrate.
The polymerization temperature is the temperature required for polymerization of the first component and the second component. The polymerization temperature is not particularly limited and may be adjusted based on a type of a nitrogen-containing carbonyl compound to be formed, and the specific first component and second component to be polymerized, for example. The polymerization temperature is indicated by temperature of the substrate for example when the first component and the second component are vapor-deposited and polymerized on the substrate. The specific polymerization temperature, for example, is 20° C. to 200° C. when polyureas are formed as a nitrogen-containing carbonyl compound, is 100° C. to 300° C. when polyimides are formed as a nitrogen-containing carbonyl compound, and is more preferably 38° C. to 150° C. when polyimides are formed as a nitrogen-containing carbonyl compound.
In the embodiment, the molecular structure of the first component and the molecular structure of the second component are asymmetric with each other. Here, a description that the molecular structures are asymmetric with each other indicates that basic skeletons of two molecules, excluding a substituent or a functional group, do not have point symmetry, line symmetry, plane symmetry, or rotational symmetry. For example, if the two molecules are a cyclic compound and a stranded compound, aromatic compounds with different orientations, and alicyclic compounds with cis-trans isomers (also called geometric isomers), the molecular structures of the two molecules are asymmetric with each other.
In this embodiment, the asymmetry between the molecular structure of the first component and the molecular structure of the second component reduces the occurrence of crystalline aggregation in a polymer as a polymer of the nitrogen-containing carbonyl compound grows by the film deposition process. Additionally, the occurrence of crystallites in a film due to heat treatment after film deposition is also reduced. Therefore, in the embodiment, the occurrence of crystallization in a film can be suppressed, and the occurrence of film roughness and structural defects can be prevented.
<Film Deposition Apparatus>
Next, a film deposition apparatus 1 according to the embodiment of the present invention will be described with reference to a cross-sectional view illustrated in
The treatment vessel 11 is configured as a circular shape and an airtight vacuum vessel to create a vacuum atmosphere inside. A side wall heater 12 is provided in a side wall of the treatment vessel 11. A ceiling heater 13 is provided in a ceiling (i.e., a top board) of the treatment vessel 11. A ceiling surface 14 of the ceiling (i.e., the top board) of the treatment vessel 11 is formed as a horizontal flat surface and the temperature of the ceiling surface 14 is controlled by the ceiling heater 13. Here, when the film deposition gas that can form a film at a relatively low temperature is used, the heat by the side wall heater 12 or the ceiling heater 13 is not necessary.
The stage 21 is provided at a lower side of the treatment vessel 11. The stage 21 constitutes the pedestal on which the substrate (i.e., the wafer W) is placed. The stage 21 is formed as a circular shape and the wafer W is placed on a horizontally formed surface (i.e., a top surface). Here, the substrate is not limited to the wafer W, and alternatively a glass substrate for manufacturing a flat panel display may be processed.
A stage heater 20 is embedded in the stage 21. The stage heater 20 heats a placed wafer W so that a protective film can be formed on the wafer W placed on the stage 21. Here, when the film deposition gas that can form a film at a relatively low temperature is used, it is not necessary to heat the placed wafer W by the stage heater 20.
The stage 21 is supported by the treatment vessel 11 through a support column 22 provided on a bottom surface of the treatment vessel 11. Lift pins 23 that are vertically moved are provided at positions outside of the periphery of the support column 22 in a circumferential direction. The lift pins 23 are inserted into respective through-holes provided at intervals in a circumferential direction of the stage 21. In
An exhaust port 31, which is opened, provided in the side wall of the treatment vessel 11. The exhaust port 31 is connected to an exhaust mechanism 32. The exhaust mechanism 32 is constituted by a vacuum pump, a valve, and so on with an exhaust pipe to adjust an exhaust flow rate from the exhaust port 31. Adjusting the exhaust flow rate by the exhaust mechanism 32 controls pressure in the treatment vessel 11. Here, a transfer port of the wafer W, which is not illustrated, is formed to be able to open and close at a position different from the position where the exhaust port 31 is opened in the side wall of the treatment vessel 11.
The gas nozzle 41 is also provided in the side wall of the treatment vessel 11. The gas nozzle 41 supplies the film deposition gas that includes the composition for film deposition described above into the treatment vessel 11. The composition for film deposition contained in the film deposition gas includes a first component M1 and a second component M2. The first component M1 is included in a first film deposition gas, the second component M2 is included in a second film deposition gas, and the first component M1 and the second component M2 are supplied into the treatment vessel 11.
The first component M1 included in the first film deposition gas is a monomer that can polymerize with the second component M2 to form a nitrogen-containing carbonyl compound. In the embodiment, 1,3-bis(isocyanatomethyl)cyclohexane (hereinafter referred to as H6XDI), which is a bifunctional alicyclic isocyanate, is used as the first component M1. Here, the first component M1 is not limited to H6XDI, and may be any compound that is suitable for use as the first component of the above-described composition for film deposition.
The second component M2 included in the second film deposition gas is a monomer that can polymerize with the first component M1 to form a nitrogen-containing carbonyl compound. In the embodiment, 1,3-bis(aminomethyl)cyclohexane (which will be hereinafter referred to as H6XDA) that is a two-functional alicyclic amine is used as the second component M2. Here, the second component M2 is not limited to H6XDA, and may be any compound that is suitable for use as the second component of the above-described composition for film deposition.
The gas nozzle 41 constitutes the supply (i.e., a film deposition gas supply) to supply the film deposition gas (i.e., the first film deposition gas and the second film deposition gas) for forming the protective film described above. The gas nozzle 41 is provided in the side wall of the treatment vessel 11 on a side opposite to the exhaust port 31 as viewed from the center of the stage 21.
The gas nozzle 41 is formed to project from the side wall of the treatment vessel 11 toward the center of the treatment vessel 11. An end of the gas nozzle 41 horizontally extends from the side wall of the treatment vessel 11. The film deposition gas is discharged from a discharging port opened at the end of the gas nozzle 41 into the treatment vessel 11, flows in a direction of an arrow of a dashed line illustrated in
When the end of the gas nozzle 41 is shaped to extend obliquely upward toward the ceiling surface 14 of the treatment vessel 11, the discharged film deposition gas collides with the ceiling surface 14 of the treatment vessel 11 before being supplied to the wafer W. An area where the gas collides with the ceiling surface 14 is, for example, at a position closer to the discharging port of the gas nozzle 41 than the center of the stage 21 and is near an end of the wafer W in a planar view.
As described, the film deposition gas collides with the ceiling surface 14 and is supplied to the wafer W, so that the film deposition gas discharged from the gas nozzle 41 travels a greater distance to reach the wafer W than the film deposition gas travels when the film deposition gas is directly supplied from the gas nozzle 41 toward the wafer W. When a distance in which the film deposition gas travels in the treatment vessel 11 increases, the film deposition gas diffuses laterally and is supplied with high uniformity in a surface of the wafer W.
The exhaust port 31 is not limited to a configuration in which the exhaust port 31 is provided in the side wall of the treatment vessel 11 as described above. The exhaust port 31 may be provided in the bottom surface of the treatment vessel 11. Additionally, the gas nozzle 41 is not limited to a configuration in which the gas nozzle 41 is provided in the side wall of the treatment vessel 11 as described above. The gas nozzle 41 may be provided in the ceiling of the treatment vessel 11. Here, it is preferable that an exhaust port 31 and a gas nozzle 41 are provided in the side wall of the treatment vessel 11 as described above in order to form an air flow of the film deposition gas so that the film deposition gas flows from one end to the other end of the surface of the wafer W and film deposition is performed on the wafer W with high uniformity.
The temperature of the film deposition gas discharged from the gas nozzle 41 is selectable, but the temperature observed until the film deposition gas is supplied to the gas nozzle 41 is preferably higher than the temperature in the treatment vessel 11 in order to prevent the film deposition gas from condensing in a flow path before the film deposition gas is supplied to the gas nozzle 41. In this case, the film deposition gas cools upon being discharged into the treatment vessel 11 and is supplied to the wafer W. The wafer W then adsorbs the film deposition gas being supplied to the treatment vessel 11 with the decrease in the temperature of the film deposition gas, adsorption of the film deposition gas for the wafer W becomes high, and the film deposition proceeds efficiently. Additionally, with respect to further increasing the adsorption of the film deposition gas for the wafer W, it is preferable that the temperature in the treatment vessel 11 is higher than the temperature of the wafer W (or the temperature of the stage 21 in which the stage heater 20 is embedded).
The film deposition apparatus 1 includes a gas supply pipe 52 connected to the gas nozzle 41 from the outside of the treatment vessel 11. The gas supply pipe 52 includes gas introduction pipes 53 and 54 branched at an upstream side. An upstream side of a gas introduction pipe 53 is connected to a vaporizing part 62 through a flow adjustment part 61 and a valve V1 in the indicated order.
In the vaporizing part 62, the first component M1 (H6XDI) is stored in a liquid state. The vaporizing part 62 includes a heater (which is not illustrated) for heating the H6XDI. One end of a gas supply pipe 63A is connected to the vaporizing part 62, and the other end of the gas supply pipe 63A is connected to an N2 (nitrogen) gas supply source 65 through a valve V2 and a gas heater 64 in the indicated order. With such a configuration, heated N2 gas is supplied to the vaporizing part 62, H6XDI in the vaporizing part 62 is vaporized, and mixed gas of the N2 gas used for vaporizing and H6XDI gas can be introduced to the gas nozzle 41 as the first film deposition gas.
The gas supply pipe 63A branches to form a gas supply pipe 63B at a position in a downstream direction from the gas heater 64 and in an upstream direction from the valve V2. A downstream end of the gas supply pipe 63B is connected to the gas introduction pipe 53 at a position in a downstream direction from the valve V1 and in an upstream direction from the flow adjustment part 61 through a valve V3. With such a configuration, when the first film deposition gas described above is not supplied to the gas nozzle 41, the N2 gas heated by the gas heater 64 is introduced to the gas nozzle 41 without going through the vaporizing part 62.
In
An upstream side of a gas introduction pipe 54 is connected to a vaporizing part 72 through a flow adjustment part 71 and a valve V4 in the indicated order. In the vaporizing part 72, the second component M2 (H6XDA) is stored in a liquid state. The vaporizing part 72 includes a heater (which is not illustrated) to heat the H6XDA. One end of a gas supply pipe 73A is connected to the vaporizing part 72, and the other end of the gas supply pipe 73A is connected to an N2 (nitrogen) gas supply source 75 through a valve V5 and a gas heater 74 in the indicated order. With such a configuration, heated N2 gas is supplied to the vaporizing part 72, H6XDA in the vaporizing part 72 is vaporized, and mixed gas of the N2 gas used for vaporizing and H6XDA gas can be introduced to the gas nozzle 41 as the second film deposition gas.
The gas supply pipe 73A branches to form a gas supply pipe 73B at a position in a downstream direction from the gas heater 74 and in an upstream direction from the valve V5. A downstream end of the gas supply pipe 73B is connected to the gas introduction pipe 54 at a position in a downstream direction from the valve V4 and in an upstream direction from the flow adjustment part 71 through a valve V6. With such a configuration, when the second film deposition gas described above is not supplied to the gas nozzle 41, the N2 gas heated by the gas heater 74 is introduced to the gas nozzle 41 without going through the vaporizing part 72.
In
For the gas supply pipe 52 and the gas introduction pipes 53 and 54, a pipe heater 60, for example, is provided around each of the pipes to heat the inside of a corresponding pipe to prevent H6XDI and H6XDA in the flowing film deposition gas from condensing. The pipe heater 60 adjusts the temperature of the film deposition gas to be discharged from the gas nozzle 41. In the embodiment, for convenience of illustration, the pipe heater 60 is illustrated only in a part of the pipe, but the pipe heater 60 is provided over the entire length of the pipe to prevent condensation.
When gas supplied from the gas nozzle 41 into the treatment vessel 11 is simply described as N2 gas, the gas indicates N2 gas alone supplied without going through the vaporizing parts 62 and 72 (i.e., bypassed) as described above, and is distinguished from N2 gas contained in the film deposition gas.
The gas introduction pipes 53 and 54 are not limited to the configuration in which the gas supply pipe 52 connected to the gas nozzle 41 branches. The gas introduction pipes 53 and 54 may be configured as separate gas nozzles that respectively supply the first film deposition gas and the second film deposition gas into the treatment vessel 11. This configuration can prevent the first film deposition gas and the second film deposition gas from reacting with each other and forming a film in a flow path before being supplied into the treatment vessel 11.
The film deposition apparatus 1 includes a controller 10 that is a computer, and the controller 10 includes a program, a memory, and a CPU. The program includes an instruction (each step) to proceed processing for the wafer W, which will be described later. The program is stored in a computer storage medium such as a compact disk, a hard disk, a magneto-optical disk, and a DVD, and installed in the controller 10. The controller 10 outputs a control signal to each part of the film deposition apparatus 1 by the program and the controller 10 controls an operation of each part. Specifically, operations such as control of an exhaust flow rate by the exhaust mechanism 32, control of a flow rate of each gas supplied into the treatment vessel 11 by the flow adjustment parts 61 and 71, control of an N2 gas supply from the N2 gas supply sources 65 and 75, control of power supply to each heater, and control of the lift pins 23 by the lifting mechanism 24 are controlled by the control signal.
In the film deposition apparatus 1, with the configuration described above, the composition for film deposition that includes the first component M1 and the second component M2 is supplied into the treatment vessel 11, and the first component M1 and the second component M2 are polymerized to form a nitrogen-containing carbonyl compound. In the embodiment, polymerization of the first component M1 (H6XDI) and the second component M2 (H6XDA) forms a polymer (polyurea) containing a urea bond as a nitrogen-containing carbonyl compound.
The nitrogen-containing carbonyl compound is deposited as a polymer film on the wafer W by the first film deposition gas and the second film deposition gas being vapor-deposited and polymerized on the surface of the wafer W. The polymer film that is formed of a nitrogen-containing carbonyl compound can be a protective film that prevents a specific portion of the wafer W from being etched for example, as described below.
Here, the cis and trans isomers are present in H6XDI constituting the first component M1 included in the first film deposition gas. Thus, the molecular structure of H6XDI contains cis isomers and trans isomers in a constant ratio. Additionally, the cis and trans isomers are also present in H6XDA that constitutes the second component M2 included in the second film deposition gas. Thus, the molecular structure of H6XDA contains cis isomers and trans isomers in a constant ratio.
Accordingly, in the film deposition apparatus 1, the molecular structure of the first component M1 (H6XDI) included in the first film deposition gas supplied into the treatment vessel 11 and the molecular structure of the second component M2 (H6XDA) included in the second deposition gas are asymmetric with each other. Therefore, in the film deposition process using the film deposition apparatus 1, the occurrence of crystallization in a film can be suppressed, and the occurrence of film roughness and structural defects can be prevented.
In the embodiment, cis isomers and trans isomers are present in both the first component M1 and the second component M2. However, a mixture of cis isomers and trans isomers may be present in only one of either the first component M1 or the second component M2 so that the molecular structure of the first component M1 and the molecular structure of the second component M2 are asymmetric.
Additionally, a case in which the molecular structure of the first component M1 and the molecular structure of the second component M2 are asymmetric, is not limited to the case in which either the first component M1 or the second component M2 contains cis-trans isomers as described above. For example, the molecular structure of the first component M1 and the molecular structure of the second component M2 are asymmetric with each other in a case of a cyclic compound and a chain compound, aromatic compounds with different orientations, and the like.
Next, a process performed on the wafer W using the film deposition apparatus 1 described above will be described with reference to
The first film deposition gas that includes H6XDI is supplied from the first film deposition gas supply mechanism 5A to the gas nozzle 41 and the N2 gas is supplied from the second film deposition gas supply mechanism 5B to the gas nozzle 41. These are mixed to be at 140° C. and discharged from the gas nozzle 41 into the treatment vessel 11 (see
Subsequently, the N2 gas is supplied from the first film deposition gas supply mechanism 5A instead of the first film deposition gas, and only N2 gas is discharged from the gas nozzle 41 (time t2). The N2 gas operates as a purge gas and the first film deposition gas that is not adsorbed on the wafer W in the treatment vessel 11 is purged.
Subsequently, the second film deposition gas that includes B6XDA is supplied to the gas nozzle 41 from the second film deposition gas supply mechanism 5B. These are mixed to be at 140° C. and discharged from the gas nozzle 41 (time t3). The mixed gas including the second film deposition gas is cooled down in the treatment vessel 11, is flowed through the treatment vessel 11, is supplied to the wafer W, and is further cooled down on the wafer W surface, in a manner similar to the mixed gas that includes the first film deposition gas supplied into the treatment vessel 11 from the time t1 to the time t2. The second film deposition gas included in the mixed gas is adsorbed on the wafer W.
The adsorbed second film deposition gas polymerizes with the first film deposition gas already adsorbed on the wafer W, and a polyurea film is formed on the surface of the wafer W. Consequently, the N2 gas is supplied from the second film deposition gas supply mechanism 5B instead of the second film deposition gas, and only N2 gas is discharged from the gas nozzle 41 (time t4). The N2 gas operates as a purge gas to purge the second film deposition gas that is not adsorbed on the wafer W in the treatment vessel 11.
In a series of the processes described above, the gas nozzle 41 first discharges the mixed gas including the first film deposition gas, then discharges only the N2 gas, and finally discharges the mixed gas including the second film deposition gas. When this series of the processes is defined as one cycle, the cycle is repeated after the time t4, and the polyurea film thickness increases. When a predetermined number of cycles are performed, the discharge of gas from the gas nozzle 41 stops.
In the embodiment, the molecular structure of the first component M1 (H6XDI) included in the first film deposition gas and the molecular structure of the second component M2 (H6XDA) included in the second film deposition gas are asymmetric with each other. In the film deposition apparatus 1, because the first film deposition gas and the second film deposition gas are supplied to the wafer W in the treatment vessel 11, it is possible to obtain an effect similar to a case in which the composition for film deposition described above is used. That is, according to the film deposition apparatus 1 of the embodiment, the occurrence of crystallization in a film can be suppressed, and the occurrence of film roughness and structural defects can be prevented in a film deposition process.
An example of a process performed using the film deposition apparatus 1 and an etching apparatus will be described.
First, after a recess 85 is formed in the interlayer insulating film 82 by the etching apparatus (
As illustrated in
If the temperature of the first film deposition gas and the temperature of the second film deposition gas are relatively high, adsorption and film deposition on a surface tend to be difficult to occur. Thus, as illustrated in a timing chart of
As illustrated in
In the following, the present invention will be described specifically with reference to examples. In the examples and a comparative example, measurement and evaluation were performed as follows.
[Film Deposition]
A film deposition apparatus 101 illustrated in
[Heat Treatment]
A wafer W on which a polymer film is formed, is placed in a hot plate (which is not illustrated) of a nitrogen atmosphere and heated at 250° C. for 5 minutes.
[Dark Field Observation]
The surface of the polymer film deposited on the wafer W was observed before and after heat treatment in the dark field using an optical thin film and scatterometry (OCD) measuring device (which is a device named “n&k Analyzer” and manufactured by n&k Technology). When light scattering was observed by the dark field observation, it was evaluated that film roughness (crystallization) occurred. The evaluation was performed using pictures of the surface of the film imaged in the dark field (as illustrated in
In the following, an example and a comparative example will be described.
1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) was supplied as the first component M1, 1,3-bis(aminomethyl)cyclohexane (H6XDA) was supplied as the second component M2, and a polymer film is formed on the wafer W. Both H6XDI constituting the first component M1 and H6XDA constituting the second component M2 are compounds in which cis isomers and trans isomers are present. In Example 1, the surface of the film was evaluated before and after the heat treatment. The results are indicated in Table 1 and
With the exception that 1,3-bis(isocyanatomethyl)benzene (XDI) was supplied instead of H6XDI as the first component M1, and 1,3-bis(aminomethyl)benzene (XDA) was supplied instead of H6XDA as the second component M2, the film was formed and evaluated in a manner similar to Example 1. Both XDI and XDA are meta-oriented aromatic compounds. The results are indicated in Table 1 and
From Table 1, when the cis-trans isomer exists in the first component M1 (Example 1), light scattering was not observed before and after the heat treatment.
With respect to this, when both the first component M1 and the second component are aromatic compounds and have the same orientation in the basic structure (Comparative example 1), light scattering was observed after the heat treatment.
From these results, it has been found that film roughness (crystallization in a film) is suppressed. This can be achieved by performing the film deposition process using a composition for film deposition in which the molecular structures of the first component that polymerizes with the second component to form a nitrogen-containing carbonyl compound is asymmetric with each other.
Example embodiments of the present invention have been described in detail above, but the present invention is not limited to a specific embodiment. The various modifications and alterations may be made within the scope of the invention described in the claims.
This international application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2018-108154, filed Jun. 5, 2018, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-108154 | Jun 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/020631 | 5/24/2019 | WO | 00 |
