JP5124111B2 - Film forming material - Google Patents

Description

  The present invention relates to a molecular assembly, in particular, an assembly of small organic molecules.

  In the manufacture of semiconductor integrated circuits, especially VLSI, advanced microfabrication technology is required to achieve high density and high integration, and development of high-resolution resists applicable to this microfabrication technology Is underway.

  For example, Patent Document 1 describes a positive photosensitive composition containing a resin soluble in an alkaline aqueous solution, an acid generator, and a compound having at least two groups that are decomposed by an acid. Patent Document 2 discloses that an alkali-soluble resin in which a part of an alkali-affinity functional group is protected with an acid-dissociable group, a radiation-sensitive acid generator, and a hydrogen atom of a low-molecular phenolic compound are bonded to an alkoxyalkyl group or t- A radiation sensitive resin composition containing a compound substituted with an alkoxycarbonylalkyl group is described.

JP-A-6-51519 Japanese Utility Model Publication No. 6-167711

The compositions described in the above patent documents are intended to realize a high-resolution resist by increasing the sensitivity to short-wavelength exposure sources such as KrF excimer laser, ArF excimer laser, and F ₂ excimer laser. Each of the resists is a polymer film, that is, a polymer aggregate. Since the polymer has a distribution in the degree of polymerization and the molecular weight is not constant, the film is not exposed to the exposed area even if it is derived from a composition with enhanced sensitivity to short wavelength exposure sources. The generation state tends to be unstable or non-uniform in the boundary area with the exposure part, and there is an obstacle in achieving the essential high resolution. That is, in order to realize a high-resolution resist essentially, it is not sufficient to increase the sensitivity of the photosensitive composition, and it is necessary to improve the resist at the molecular level.

  An object of the present invention is to realize an assembly of small organic molecules that can be used, for example, as a resist.

The present invention relates to a film-forming material for forming a molecular film on the surface of a substrate. This film-forming material comprises compound A in which an organized atomic group is bonded to a fluorene skeleton, and 1-aminopentane. Preparing a solution in which at least one compound B selected from the group consisting of 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid and cyanuric acid is dissolved in a solvent, and stirring the solution It is obtained by a production method including a step and a step of separating a solid produced by stirring the solution from the solution.

Another film-forming material according to the present invention relates to a film-forming material for forming a molecular film on the surface of a substrate. Compound A in which an organized atomic group is bonded to a fluorene skeleton, and 1-amino Adding at least one compound B selected from the group consisting of pentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid and cyanuric acid to a medium to prepare a suspension; It is obtained by a production method including a step of stirring a suspension and a step of separating a solid produced by stirring the suspension from the suspension.

The organized atomic group of compound A used in the production of the film-forming material of the present invention is an atomic group containing at least one structure selected from the group consisting of a carboxyl group, a hydroxyl group , an amino group, and an aromatic ring.

The method for forming a molecular film according to the present invention is a method for forming a molecular film on the surface of a substrate, a step of preparing a solution in which the film-forming material of the present invention is dissolved in a solvent , and the prepared solution as a substrate. And applying to the substrate.

The paint for forming a molecular film of the present invention is for forming a molecular film on the surface of a substrate, and contains the film forming material of the present invention and a solvent in which the film forming material is dissolved.

The molecular film of the present invention is formed using the film forming material of the present invention. Further, the molecular film of the present invention comprises an organized compound A in which an organized atomic group is bonded to a fluorene skeleton, 1-aminopentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid, and cyanur. At least one selected from the group consisting of a carboxyl group, a hydroxyl group , an amino group, and an aromatic ring, having a structural unit comprising at least one compound B selected from the group consisting of acids. It is an atomic group containing one structure, and the structural units are regularly arranged.

The present invention uses the compound A in which the organized atomic group is bonded to the fluorene skeleton, and the compound A and the compound B that can be organized. Therefore, the molecular film in which the structural unit composed of the compound A and the compound B is organized. Can be realized. This molecular film is useful, for example, as a resist used during microfabrication for manufacturing a semiconductor integrated circuit.

  The molecular assembly of the present invention is prepared using a fluorene-based low molecular compound, and the fluorene-based low molecular compound and an organic low-molecular compound that can be organized. Here, “organization” means a gradual action between compounds not based on a covalent bond, for example, hydrogen bond, van der Waals force, permanent dipole interaction, permanent dipole-induced dipole interaction, Temporary dipole-induced dipole interaction, charge transfer force interaction between electron donor and electron acceptor, coordination bond, ionic bond, electrostatic interaction, and hydrophilic and hydrophobic affinity This means that molecules are assembled by forming loose bonds between molecules.

  The fluorene-based low molecular weight compound used in the present invention is a compound in which an atomic group including an organized structure (hereinafter referred to as “organized atomic group”) is bonded to a fluorene skeleton represented by the following formula (1), and has a molecular weight Is fixed. Therefore, even a compound having a fluorene structure to which organized atomic groups are bonded does not belong to the concept of a fluorene-based low molecular weight compound. The organized atomic group may be bonded to any position of 1 to 9 shown in Formula (1). In the fluorene skeleton, the organized atomic group may be bonded to two or more positions 1 to 9 described above. In this case, two or more kinds of organized atomic groups may be bonded to the fluorene skeleton.

  The organized structure included in the organized atomic group is a chemical structure that can form a loose bond between molecules, not based on the covalent bond as described above, such as a carboxyl group, a carbonyl group, a hydroxyl group, an amino group, and an aromatic group. It has at least one structure selected from the group consisting of rings.

  Specific examples of the above-described fluorene-based low molecular weight compound usable in the present invention include 9-fluorenol, 2,7-dibutylfluorene-9-carboxylic acid, 9,9-bis (4-aminophenyl) fluorene, 2-acetylfluorene, 2,7-diaminofluorene, 2-amino-7-bromofluorene, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) fluorene 9,9-bis (4-amino-3-fluorophenyl) fluorene, 9,9-bis (4-amino-3-hydroxyphenyl) fluorene, and the like.

  The fluorene-based low molecular weight compound used in the present invention and the organic low-molecular weight compound that can be organized contain the same organized atomic groups as those mentioned for the fluorene-based low molecular weight compound, and the molecular weight is determined. Is. Therefore, even an organic compound containing an organized atomic group does not belong to the concept of a low molecular weight organic compound.

  Examples of the above-mentioned organic low molecular weight compounds that can be used in the present invention include 1-aminopentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid, cyanuric acid, barbituric acid, parabanic acid, 2, 4 -Other than fluorene compounds such as dioxohexahydro-1,3,5-triazine, uracil, thymine, pyrogallol, pyridine and 4-methylpyridine. Further, the organic low molecular weight compound may be another fluorene based low molecular weight compound different from that used as the fluorene based low molecular weight compound among the fluorene based low molecular weight compounds having the above-mentioned conditions. Two or more organic low molecular weight compounds may be used. For example, two or more organic low molecular compounds other than fluorene low molecular compounds, a combination of organic low molecular compounds other than fluorene low molecular compounds and fluorene low molecular compounds, or two or more fluorene low molecular compounds Molecular compounds may be used.

  However, in the present invention, the organic low-molecular compound includes an organized structure that can be organized with a fluorene-based low-molecular compound by interaction with the organized structure of the organized atomic group of the fluorene-based low-molecular compound. It is necessary to select and use. Moreover, it is necessary to select an organic low molecular weight compound which can produce | generate a solid substance by interaction with a fluorene type low molecular weight compound in the stirring process of the manufacturing method mentioned later.

  The molecular assembly of the present invention can be obtained by the following two production methods.

Manufacturing method 1
In this production method, first, a solution in which the above-described fluorene-based low molecular compound and organic low molecular compound are dissolved in a solvent is prepared. The solvent used here is capable of simultaneously dissolving a fluorene-based low molecular weight compound and an organic low molecular weight compound. For example, alcohols such as methanol, ethanol, n-propanol, iso-propanol and butanol, dimethyl ether, diethyl Mention may be made of ethers such as ether, 1,4-dioxane and tetrahydrofuran, ketones such as acetone, methyl isobutyl ketone and diethyl ketone, and aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene.

  In this case, the amount of the organic low molecular compound used is usually preferably set to 0.1 to 2 equivalents and more preferably set to 0.5 to 1 equivalents of the fluorene low molecular compound. When the amount of the organic low molecular compound used is less than 0.1 times equivalent, the target molecular assembly may not be obtained. On the other hand, when it exceeds 2 times equivalent, a by-product may be generated.

  Next, a solution in which the fluorene-based low molecular weight compound and the organic low molecular weight compound are dissolved in the solvent is stirred by a conventional method. Stirring may be performed at room temperature (usually 23 to 26 ° C.) or may be performed while heating. However, in general, the target molecular assembly can be prepared more rapidly by heating. In the case of heating, the temperature of the solution is usually preferably set to 40 to 80 ° C.

  The stirring of the solution is not limited in time, but is continued at least until a precipitated or suspended solid is formed in the solution. Incidentally, when stirring a solution at room temperature, stirring time is about 4 to 8 hours normally.

  Next, the solid produced by stirring the solution is separated from the solution. The separation method can be carried out by a conventional method such as a method of removing the solvent by filtration, centrifugation and vacuum distillation. The separated solid can be appropriately washed with a solvent.

  The solid separated from the solution is the molecular assembly of the present invention. This molecular assembly has structural units composed of organized fluorene-based low molecular weight compounds and organic low molecular weight compounds, and these structural units are regularly arranged. This can be confirmed by structural analysis such as X-ray powder method and infrared absorption spectrum method.

Manufacturing method 2
In this production method, first, the above-mentioned fluorene-based low molecular weight compound and organic low molecular weight compound are charged into a medium to prepare a suspension. The medium used here is one that does not dissolve the fluorene-based low molecular weight compound and the organic low molecular weight compound, and is usually water. The medium may be a mixture of water, alcohols, ketones, and ethers.

  The fluorene-based low molecular weight compound and the organic low molecular weight compound to be charged into the medium are preferably charged into the medium in the form of a solution previously dissolved in a solvent. The solvent used in this case can be suspended in a medium, for example, an aromatic hydrocarbon solvent such as benzene, toluene, xylene and mesitylene, methanol, ethanol, n-propanol, iso-propanol, butanol, Polar solvents such as dimethyl ether, diethyl ether, 1,4-dioxane, tetrahydrofuran and acetone.

  In this production method, the use amount of the organic low molecular weight compound is preferably set to 0.1 to 2 times equivalent of the fluorene-based low molecular weight compound as in Production Method 1, and is set to 0.5 to 1 time equivalent. Is more preferable.

  Next, the suspension prepared as described above is stirred by a conventional method. Stirring may be performed at room temperature (usually 23 to 26 ° C.) or may be performed while heating. However, in general, the target molecular assembly can be prepared more rapidly by heating. In the case of heating, the temperature of the suspension is usually preferably set to 40 to 80 ° C.

  Stirring of the suspension is not limited in time, but is continued until at least a suspended solid is formed in the suspension. Incidentally, when stirring a suspension at room temperature, the stirring time is usually about 4 to 8 hours.

  Next, the solid produced by stirring the suspension is separated from the suspension. At this time, a separation method similar to the manufacturing method 1 can be employed. The separated solid can be washed with a solvent or water as appropriate.

  The solid separated from the suspension is the molecular assembly of the present invention. This molecular assembly has structural units composed of organized fluorene-based low molecular weight compounds and organic low molecular weight compounds, and these structural units are regularly arranged. This can be confirmed by structural analysis such as X-ray powder method and infrared absorption spectrum method.

  The molecular assembly of the present invention can be used as a film forming material. For example, the molecular assembly of the present invention can be used as a material for forming a molecular film on the surface of a substrate. In this case, first, a paint using the molecular assembly of the present invention is prepared. This paint can be prepared by dissolving the molecular assembly obtained by the above-described production method 1 or production method 2 in a solvent. The solvent used here can dissolve the molecular assembly and can be easily volatilized at room temperature or by heating. For example, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate And solvents for dissolving resist such as diacetalcohol and general-purpose solvents such as tetrahydrofuran, methyl isobutyl ketone, methanol and ethanol.

  Next, the prepared coating material is applied to the substrate to volatilize the solvent. Thereby, the thin layer by the molecular assembly of this invention is formed in the surface of a base material. Various methods such as a brush coating method, a spray method, a spin coating method, and a casting method can be employed as a method for applying the paint to the substrate. However, the spin coating method is particularly preferable. In addition, the paint applied to the substrate may be allowed to stand at room temperature to volatilize the solvent naturally, or the solvent may be forcibly volatilized by blowing or heating.

  The thin layer obtained on the base material by the above-described coating material is one in which the molecular assembly of the present invention is organized in a plane. That is, it has structural units composed of organized fluorene-based low molecular weight compounds and organic low molecular weight compounds, and these structural units are regularly organized and arranged in a planar shape. Therefore, this thin layer can control the film formation state by the structural unit or the molecular unit of the fluorene-based low molecular compound or the organic low molecular compound. For this reason, this thin layer is useful as a high-resolution resist that is demanded in a microfabrication technique at the time of manufacturing a semiconductor integrated circuit, particularly, an VLSI.

Example 1
0.56 g 1-aminodecane (3.5 mmol) and 1.01 g 2,7-dibutylfluorene-9-carboxylic acid (3.1 mmol) are dissolved in 20 ml 1,4-dioxane and the solution Was prepared. When this solution was stirred at room temperature (25 ° C.) for 6 hours, a precipitate was formed in the solution. The solution was filtered to separate the precipitate, which was washed with methanol. And the precipitate after washing | cleaning was vacuum-dried at 60 degreeC for 8 hours, and 1.56 g of powder was obtained.

The obtained powder was analyzed by infrared absorption spectroscopy (IR), and as a result, new absorption not observed in the raw material, that is, formation of a primary ammonium salt that is a molecular aggregate was suggested at 1600 cm ⁻¹ and 1500 cm ^−1. Nearby absorption was observed. Moreover, the result of having analyzed the obtained powder by the powder X ray analysis method is shown in FIG. FIG. 1 shows a peak indicating that the molecules are arranged and organized, and the obtained powder is a structural unit in which 2,7-dibutylfluorene-9-carboxylic acid and 1-aminodecane are organized. (Ie, primary ammonium salt) is an ordered molecular assembly.

Example 2
A solution was prepared by dissolving 5.46 g 9-fluorenol (30 mmol) and 2.10 g trimesic acid (10 mmol) in 50 ml 1,4-dioxane. When this solution was stirred at room temperature (25 ° C.) for 6 hours, a precipitate was formed in the solution. The solution was filtered to separate the precipitate, which was washed with methanol. The white solid thus obtained was vacuum-dried at 60 ° C. for 8 hours to obtain 7.51 g of powder.

The obtained powder was analyzed by infrared absorption spectroscopy (IR), and as a result, characteristic absorption of 3200 to 2500 cm ⁻¹ indicating a hydrogen bond between a hydroxyl group and a carboxyl group, suggesting the formation of a molecular assembly. Was observed.

Example 3
A solution of 1.77 g 9,9-bis (4-aminophenyl) fluorene (5 mmol) and 1.96 g cyanuric acid (15 mmol) dissolved in 50 ml toluene was prepared. This toluene solution was suspended in 50 ml of water and suspended at room temperature (25 ° C.) for 8 hours. Then, the suspension was filtered to separate the suspended matter, and this suspended matter was washed with water to obtain a white solid. The white solid was vacuum dried at 80 ° C. overnight to give 3.37 g of powder.

  The obtained powder was analyzed by infrared absorption spectroscopy (IR), and as a result, absorption due to amino groups present in the raw material was shifted to the short wavelength side. This means the formation of hydrogen bonds between the raw materials, suggesting the formation of molecular aggregates.

Example 4
The powder obtained in Example 1 was dissolved in propylene glycol monomethyl ether to prepare a paint having a concentration of 15% by weight. This paint was applied to a silicon wafer at a rotational speed of 1500 rpm for 20 seconds using a spin coater, and prebaked at 110 ° C. for 1 minute on a hot plate. As a result, a thin film was formed on the silicon wafer. An atomic force microscope (AFM) photograph of this film is shown in FIG.

Example 5
The powder obtained in Example 2 was dissolved in propylene glycol monomethyl ether to prepare a paint having a concentration of 15% by weight. This paint was applied to a silicon wafer at a rotational speed of 1500 rpm for 20 seconds using a spin coater, and prebaked at 110 ° C. for 1 minute on a hot plate. As a result, a thin film was formed on the silicon wafer.

2 is a chart showing X-ray analysis results of the powder obtained in Example 1. FIG. 4 is an atomic force micrograph of the thin film obtained in Example 4.

Claims (6)

A film forming material for forming a molecular film on the surface of a substrate,
Compound A having an organized atomic group bonded to a fluorene skeleton, and at least one compound B selected from the group consisting of 1-aminopentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid and cyanuric acid A step of preparing a solution in which is dissolved in a solvent;
Stirring the solution;
Separating the solid produced by the stirring from the solution, and
The organized atomic group of Compound A is an atomic group including at least one structure selected from the group consisting of a carboxyl group, a hydroxyl group , an amino group, and an aromatic ring.
Film forming material. A film forming material for forming a molecular film on the surface of a substrate,
Compound A having an organized atomic group bonded to a fluorene skeleton, and at least one compound B selected from the group consisting of 1-aminopentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid and cyanuric acid To prepare a suspension by adding
Stirring the suspension;
Separating the solid produced by the stirring from the suspension, and
The organized atomic group of Compound A is an atomic group including at least one structure selected from the group consisting of a carboxyl group, a hydroxyl group , an amino group, and an aromatic ring.
Film forming material. A method of forming a molecular film on the surface of a substrate,
Preparing a solution in which the film-forming material according to claim 1 or 2 is dissolved in a solvent;
Applying the solution to the substrate;
A method for forming a molecular film comprising: A paint for forming a molecular film on the surface of a substrate,
The film-forming material according to claim 1 or 2,
A solvent in which the film-forming material is dissolved;
A coating for forming a molecular film.   A molecular film formed using the film forming material according to claim 1. At least selected from the group consisting of a compound A having an organized atomic group bonded to a fluorene skeleton, and 1-aminopentane, 1-aminooctane, 1-aminododecane, 1-aminodecane, trimesic acid and cyanuric acid Having a structural unit consisting of one compound B;
The organized atomic group of Compound A is an atomic group including at least one structure selected from the group consisting of a carboxyl group, a hydroxyl group , an amino group, and an aromatic ring, and the structural units are regularly arranged. Yes,
Molecular film.