JP2010250118A - Fine pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming fine patterns which is made finer and has high dry etching resistance. <P>SOLUTION: The pattern forming method includes applying and curing a composition for fine pattern formation, having a silazane bond on surfaces of patterns formed on a substrate. A pretreatment composition, including a basic compound can be also applied prior to the application of the composition for fine pattern formation. By utilizing a cured layer of the composition for fine pattern formation formed by the method, other patterns being made finer can be formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fine pattern forming method for reducing the pitch size or pattern opening size of a resist pattern already formed when forming a resist pattern in a manufacturing process of a semiconductor or the like.

  In order to form a finer pattern using a general photolithography technique, it is necessary to improve the exposure apparatus. In particular, in order to form a pattern having a pitch size of 60 nm or less by an optical lithography technique, a special apparatus such as immersion optical lithography recently developed is required, and enormous investment is required.

  For this reason, various techniques for obtaining a fine pattern without using such an expensive apparatus have been studied. The most practical method is to refine the resist pattern by forming a coating layer on the formed resist pattern using a composition containing a water-soluble resin and, if necessary, an additive. Is. This technique can form a fine pattern that exceeds the limit of photolithography regardless of the exposure wavelength. Such a technique has a short history and has been implemented for about 10 years.

For example,
(1) A method of forming a resist pattern, then applying a mixing generation resist, baking to form a mixing layer, developing to a fine pattern dimension, and forming a pattern (Patent Document 1),
(2) A positive photoresist pattern is formed on a substrate and then uniformly irradiated with electromagnetic radiation, and then a water-based paint is uniformly applied, and the positive photoresist is dissolved and peeled off with an alkaline aqueous solution (lift-off). ) To form a fine pattern of water-based paint (Patent Document 2),
(3) The resist pattern containing a material that generates an acid upon exposure is covered with a resist containing a material that crosslinks in the presence of the acid, and an acid is generated in the resist pattern by heating or exposure to cause crosslinking at the interface. A method in which a layer is formed as a coating layer of a resist pattern, the resist pattern is thickened, and a reduction in the hole diameter or separation width of the resist pattern is achieved (Patent Document 3),
(4) A fine pattern forming material obtained by dissolving a completely water-soluble crosslinking agent selected from glycol lauryl in which at least one imino group hydrogen atom is substituted with a hydroxyalkyl group, and a water-soluble resin in an aqueous medium. In addition, after forming a resist pattern on the substrate using a chemically amplified resist containing an acid generator, a coating film made of the fine pattern forming material is provided on the resist pattern, and heat treatment is performed to coat the resist pattern and the resist pattern. A method of forming a fine pattern by forming a water-insoluble reaction layer at the interface with the film and then removing the non-reacted portion of the coating film with an aqueous solvent (Patent Document 4),
(5) The surface layer portion of the resist pattern is infiltrated with a chemical solution containing a crosslinking agent that crosslinks due to the presence of an acid and a swelling accelerator to swell the surface layer portion, and a crosslinked film is formed on the swollen surface layer portion of the resist pattern. A method of forming a resist pattern 2 (Patent Document 5),
(6) A resist pattern is covered with a first upper layer film containing an acid component, and a second upper layer film containing a basic component is further formed thereon, and then the acid component is put into the first resist pattern by heat treatment. The basic component is diffused into the first upper layer film to form a solubilized layer in the resist pattern, while the acid component is formed in the vicinity of the interface between the first upper layer film and the second upper layer film. A method of reducing the pattern width by removing the solubilized layer (Patent Document 6),
(7) A resist pattern refinement coating forming agent containing a copolymer of (meth) acrylic acid monomer and water-soluble vinyl monomer is applied to the entire surface or a part of the resist pattern formed on the substrate, and further heated. A method for making the pattern finer by thermally shrinking the resist pattern (Patent Document 7),
(8) A resist pattern forming method in which a resist pattern thickening material containing a resin and a surfactant is applied after applying the surfactant-containing liquid (Patent Document 8)
Etc. have been proposed.

  These methods can easily form a fine pattern that generally exceeds the resolution limit of photolithography. However, since the coating film formed on the pattern surface by these methods is generally formed of an organic substance, it tends to have poor etching resistance.

JP-A-5-166717 JP-A-7-191214 Japanese Patent Laid-Open No. 10-73927 JP 2000-267268 A Japanese Patent Application Laid-Open No. 2001-1000042 JP 2002-6512 A JP 2003-84459 A JP 2004-191465 A

  In the method of making a pattern fine as described above, in order to improve the etching resistance of a film formed on the pattern surface, it is conceivable to form the film with an inorganic material. According to the study by the present inventors, it was found that the etching resistance can be improved by forming the coating film with a siliceous material derived from the polysilazane composition, and the present invention has been completed. The present invention intends to provide a method capable of forming a thicker film, forming a finer pattern, and further improving dry etching resistance, not only using a polysilazane composition. Is.

A fine pattern forming method according to an embodiment of the present invention includes:
Forming a first convex pattern having convex portions on the surface of the substrate;
An application step of applying a resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern, and a solvent that dissolves the resin and does not dissolve the convex pattern,
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
The step of rinsing the substrate after the curing step to remove the uncured resin composition, and removing the cured layer formed on the upper surface of the convex portion, the first on the side wall of the convex portion The substance constituting the convex pattern includes a step of forming a layer made of a different kind of substance.

A fine pattern forming method according to another embodiment of the present invention includes:
Forming a first convex pattern having convex portions on the surface of the substrate;
A pretreatment step of applying a pretreatment composition comprising a basic compound on the first convex pattern;
An application step of applying a resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern;
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
Removing the uncured resin composition by rinsing the substrate after the curing step;
Removing the hardened layer formed on the upper surface of the convex part to form a layer made of a substance different from the substance constituting the first convex pattern on the side wall of the convex part; and It is characterized in that it includes a step of forming a fine second convex pattern made of the different kind of material by removing the portion.

A fine pattern forming method according to still another embodiment of the present invention includes:
Forming a first convex pattern having convex portions on the surface of the substrate;
A step of applying a pretreatment composition comprising a basic compound on the first convex pattern. A resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern. Coating process to apply,
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
Removing the uncured resin composition by rinsing the substrate after the curing step;
Removing a hardened layer formed on the upper surface of the convex part to form a layer made of a substance different from the substance constituting the first convex pattern on the side wall of the convex part;
The step of embedding a material equivalent to the first convex pattern in the space portion to form a compensation pattern for the first convex pattern, and removing the layer made of the different kind of substance, The method includes a step of forming a fine pattern including a pattern and a compensation pattern for the first convex pattern.

  According to the present invention, a pattern formed by a conventional method can be miniaturized, and at the same time, dry etching resistance can be improved. By combining the treatment with the pretreatment composition, the pattern can be further refined and the pattern size can be adjusted. Furthermore, higher dry etching resistance can be achieved at the same time by using a polymer in the pretreatment composition.

The figure which shows typically the fine pattern formation method by one embodiment of this invention. The figure which shows typically the fine pattern formation method by other one Embodiment of this invention. The figure which shows typically the fine pattern formation method by other one Embodiment of this invention.

Fine pattern forming method According to an embodiment of the present invention, a fine pattern forming method includes a resin comprising a repeating unit having a silazane bond as a fine pattern forming composition, a solvent that dissolves the resin and does not dissolve a resist pattern. A conventionally known method is used except that a composition for forming a fine pattern comprising is used. Therefore, the photoresist used for forming the resist pattern and the method for forming the resist using the photoresist may be either a conventionally known photoresist or a conventionally known resist forming method. In addition, the resist pattern can use the arbitrary thing generally used. In addition, as a method of coating the resist pattern with the composition for forming a fine pattern, any conventionally known method can be used.

  An embodiment of the fine pattern forming method according to the present invention will be described with reference to the drawings. In the following description, a case where a resist pattern is formed using an ArF resist will be described as an example.

  FIGS. 1A to 1G are conceptual diagrams for explaining a method of making a pattern finer by using the composition for forming a fine pattern of the present invention on the surface of a resist pattern. In each figure, the board | substrate 1, the resist pattern 2, the composition layer 3 for fine pattern formation, and the hardening layer 4 formed by hardening | curing the composition layer for fine pattern formation are shown as a schematic cross section.

  First, a resist (for example, a positive chemical amplification resist) is applied on a substrate 1 such as a semiconductor substrate, and exposed and developed by a normal method to form a positive resist pattern 2. Here, the resist used is not particularly limited and can be arbitrarily selected from those generally used. Further, depending on the purpose, a substrate made of glass or metal, a substrate in which a semiconductor layer or a resin layer is formed on a support, and the like can be used. In particular, using the pattern formed by the method of the present invention as a pattern mask, a semiconductor layer or a resin layer formed on the substrate surface is processed to form a fine pattern or a pattern mask for further pattern formation. In this case, a film suitable for such processing can be provided on the substrate. Details of such various substrates will be described later.

  Next, as necessary, a pretreatment composition is applied so as to cover the surface of the resist pattern 2 as shown in FIG. In other words, the pretreatment composition can be applied before application of the composition for forming a fine pattern, if necessary.

  The pretreatment composition used as necessary in the present invention contains a basic compound. This basic compound acts as a catalyst for a reaction in which a resin having a silazane bond contained in a composition for forming a fine pattern to be applied thereafter is cured, thereby thickening the cured layer and / or drying the cured layer. It is considered to have an effect of improving etching resistance, and pretreatment with a pretreatment composition is preferably performed.

  As such a basic compound, any compound can be used. However, a basic compound containing a metal ion may cause a problem when a pattern to be formed is used for a semiconductor element or the like. For this reason, the basic compound preferably contains no metal ions.

（式中、Ｒ^ａ〜Ｒ^ｄは、それぞれ独立に、水素、炭素数１〜４の飽和炭化水素基、および炭素数１〜４のアルカノール基からなる群から選択される基であるか、Ｒ^ａ〜Ｒ^ｄのうちの２つが共有結合により結合されて炭素数２〜５の炭素環、含酸素炭素環、または含窒素炭素環を形成しており、ただし、式（Ａ）および（Ｂ）において、Ｒ^ａ〜Ｒ^ｄは同時に水素ではなく、ｎは１〜３の数である。） One such basic compound is preferably selected from the group consisting of nitrogen-containing basic compounds having a relatively low molecular weight, for example, a molecular weight of 1000 or less. Such a nitrogen-containing basic compound is considered to act as a catalyst when the composition for forming a fine pattern is cured. Specifically, it is preferable that the nitrogen-containing basic compound is represented by the following general formulas (A) to (C).

(Wherein R ^{a to} R ^d are each independently a group selected from the group consisting of hydrogen, a saturated hydrocarbon group having 1 to 4 carbon atoms, and an alkanol group having 1 to 4 carbon atoms, or R ^{two of a to} R ^d are bonded by a covalent bond to form a carbocycle having 2 to 5 carbon atoms, an oxygen-containing carbocycle, or a nitrogen-containing carbocycle, provided that the formulas (A) and (B) R ^{a to} R ^d are not hydrogen at the same time, and n is a number from 1 to 3.)

  Among such nitrogen-containing basic compounds, ethylenediamine, propylenediamine, piperidine, piperazine, hydroxyethylpiperazine, ethanolamine, isopropanolamine, diethanolamine, N-methylethanolamine, N-ethylethanolamine, N, N-dimethylethanol Those selected from the group consisting of amine, N, N-diethylethanolamine, 2- (2-aminoethylamino) ethanol, morpholine, tetramethylammonium hydroxide, and tetraethylammonium hydroxide are readily available. At the same time, it is inexpensive and preferable from the viewpoint of handleability. Moreover, when a primary amine and a secondary amine are used among the nitrogen-containing basic compounds represented by the above general formula, the variation in the thickness of the film formed by the resin composition described later is small, and adjustment becomes easy. This is preferable because the mass productivity in production increases.

  If the nitrogen-containing basic compound used is liquid at room temperature, it may be used as a pretreatment composition without using a solvent. However, from the viewpoint of applicability and the like, the pretreatment composition in the present invention generally further comprises a solvent. Such a solvent is preferably one that does not impair the shape of the formed pattern. Specific examples include water, monohydric alcohols, ethers, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, and higher hydrocarbons. Among these, water is preferable because it hardly dissolves a pre-formed pattern or a resin composition layer that is subsequently formed, and has few adverse effects. Moreover, an organic solvent can be used in the range which does not impair the effect of this invention, when there exists a reason of the solubility improvement of the component of a pre-processing composition.

  These nitrogen-containing basic compounds are preferably added to the pretreatment composition at a concentration of 0.001 to 10 wt%, more preferably 0.01 to 6 wt%, based on the total weight of the pretreatment composition. The

  In addition, the pretreatment composition in the present invention is preferable because it includes a basic polymer having a molecular weight larger than that of the above-described nitrogen-containing basic compound, since the dry etching resistance of the formed film is improved. As such a basic polymer, a polymer containing vinylimidazole, ethyleneimine, vinylamine, allylamine, amine group-containing acrylic acid, amine group-containing methacrylic acid or a mixture thereof as a polymerization unit is preferable. Polyvinylimidazole, polyethyleneimine, polyvinylamine, and polyallylamine, which are homopolymers containing these as polymerization units, are examples of preferable basic polymers. Acrylic acid, methacrylic acid, vinyl pyrrolidone, vinyl alcohol, vinyl acetate These polymers may have other polymerized units and substituents as long as the effects of the present invention are not impaired. In particular, when an acidic polymerization unit is included, the whole polymer is preferably basic. The size of the polymer is not particularly limited, but in general, the weight average molecular weight is preferably 1000 or more.

  When these basic polymers are used, they are generally used at a concentration of 0.1 to 20% by weight, preferably 1 to 6% by weight, based on the total weight of the pretreatment composition. In addition, the basic polymer has different basicity depending on the type, but the pH of the pretreatment composition preferably exceeds 7, and it is preferable that the basic polymer contains an amount of the basic polymer in an amount of 8 to 12. This is because when the pH is 8 or more, the dry etching resistance is remarkably improved, and when the pH is 12 or less, it is easy to control the thickness of the film by the resin composition described later.

  These basic compounds can also be used in combination of two or more. In particular, it is preferable to use a combination of a nitrogen-containing basic compound and a basic polymer because the formed pattern can be made finer and the dry etching resistance can be remarkably improved. Moreover, although a pre-treatment composition contains a basic compound, it can also contain an additional component as needed. For example, polymers other than basic polymers, such as acrylic polymers, methacrylic polymers, polyvinyl alcohol, vinyl acetate polymers, and the like can be included. Further, a surfactant for improving the coating property can be used.

  After applying the pretreatment composition, it can be baked as necessary. The insoluble solvent can be removed by baking, and when a polymer component is included, it can be cured. The preferable conditions for such baking vary depending on the type of pretreatment composition used, but generally 40 to 180 ° C., preferably 70 to 140 ° C., 20 to 120 seconds, preferably 60 to 90 seconds, Do.

  It is sufficient that the pretreatment composition is applied to the surface of the pattern that is formed. However, for easy processing, as shown in FIG. 1A, it may be applied to the entire surface where the pattern is formed, including the exposed substrate.

  Thus, after apply | coating a pre-processing composition, it rinses with water etc. as needed, and can also remove an excess pre-processing composition.

  The fine pattern forming composition is subsequently applied to the pattern that has been pretreated as necessary (FIG. 1B). Although not shown in FIG. 1B, when the pretreatment is performed and the pretreatment composition contains a polymer, a layer of the pretreatment composition may be formed on the surface of the pattern 2. is there.

  The fine pattern forming composition used here comprises a resin comprising a repeating unit having a silazane bond. Here, the silazane bond means a Si—N bond, which has a bond for bonding to another unit, and the remaining bond is substituted with an arbitrary substituent. Generally, the substituent is hydrogen or a hydrocarbon group, but may be substituted with a silicon-containing group or a functional group such as a hydroxyl group, a carboxyl group, or an amino group. Further, when the number of bonds in the repeating unit is 2 or more and the number of bonds is 3 or more, the resin can have a two-dimensional or three-dimensional structure.

式中、Ｒ^１〜Ｒ^３は、それぞれ独立に、水素、炭素数１〜６の飽和炭化水素基、および炭素数１〜６の飽和炭化水素基を有するシラザン基からなる群から選択される基である。飽和炭化水素基は、線状、分岐鎖状、または環状のいずれであってもよい。 Preferable examples of such repeating units include those represented by the following formula (I).

In the formula, R ^{1 to} R ³ are each independently a group selected from the group consisting of hydrogen, a saturated hydrocarbon group having 1 to 6 carbon atoms, and a silazane group having a saturated hydrocarbon group having 1 to 6 carbon atoms. It is. The saturated hydrocarbon group may be linear, branched or cyclic.

The resin represented by the above formula (I) is generally called polysilazane. This polysilazane can take a two-dimensional or three-dimensional structure when any of R ^{1 to} R ³ is a silazane group represented by the formula (I). Moreover, the repeating unit represented by the said formula (I) can also combine 2 or more types.

Among such resins, perhydropolysilazane consisting only of silicon, nitrogen and hydrogen is one of the preferred ones. One of them is that in formula (I), all of R ^{1 to} R ³ are hydrogen. In addition, other perhydropolysilazanes are used as repeating units.
- _(SiH 2 NH) - and - _(SiH 2 N) have a <city, those ends are hydrogen or -SiH _3. This perhydropolysilazane can take various structures depending on the blending ratio of the repeating units, and examples thereof include the following structures.

  The molecular weight of such a resin is arbitrarily selected depending on the type of resist to be applied, the type of target pattern, and the like, but is preferably 500 to 100,000 in terms of weight average molecular weight, and 600 to More preferably, it is 10,000.

  The composition for forming a fine pattern used in the present invention comprises a solvent. This solvent needs to be capable of dissolving the resin. That is, when the composition is applied onto the resist pattern, the composition is preferably uniform. Therefore, the solubility of the resin with respect to the solvent may be dissolved to such an extent that the composition becomes uniform. On the other hand, when applied onto the resist pattern, if the solvent dissolves the pattern, the pattern may be destroyed before the pattern is refined, so the resist pattern must not be dissolved. is there. Furthermore, it is preferable that the resin does not react.

  As the solvent that can be used for the composition for forming a fine pattern, any solvent can be selected as long as it satisfies the above conditions. Moreover, it can select according to the kind of resin to be used, the material of the resist to apply, etc. Such solvents include (a) ethers such as dibutyl ether (DBE), dipropyl ether, diethyl ether, methyl-t-butyl ether (MTBE), and anisole, and (b) saturated hydrocarbons such as decalin, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, n-nonane, i-nonane, n-decane, i-decane, ethylcyclohexane (C) unsaturated hydrocarbons such as cyclohexene, and dipentene (limonene); (d) ketones such as methyl isobutyl ketone (MIBK), (e) aromatic hydrocarbons For example, benzene, toluene, xylene, ethylbenzene, di Ethylbenzene, trimethylbenzene, and triethylbenzene like, and the like. Among these, a solvent selected from the group consisting of (a) ethers and (b) saturated hydrocarbons is preferable. More specifically, dibutyl ether and decalin change the type of resin or resist material. Even so, it is widely applicable and is a preferred solvent. These solvents can be used in combination of two or more as required.

  The composition for forming a fine pattern used in the present invention is obtained by dissolving the resin in the solvent, but the concentration is not particularly limited. However, it can be appropriately adjusted according to the coating property on the resist surface, the desired degree of miniaturization and the like. In general, the content of the resin is preferably 0.01 to 30%, more preferably 0.3 to 5%, based on the total weight of the composition.

  The composition for forming a fine pattern in the present invention may contain other additives as necessary. Such additives include surfactants, leveling agents, plasticizers and the like.

  Such a composition for forming a fine pattern is applied to form the coating layer 3. By this application, the resin 6 in the composition is physically adsorbed to the resist pattern (FIG. 1C).

  The resin adsorbed on the resist surface penetrates into the resist and the resist film swells (FIG. 1D). Here, by heating the resist, the penetration of the resin and the reaction between the resin and the resist are promoted (FIG. 1 (e)). And in the part which was not exposed at the time of creation of a resist pattern, reaction with resin and a resist hardly arises, and the thickness of a hardened layer becomes thin. On the other hand, the reaction between the resin and the resist is likely to occur in the exposed part or in the vicinity of the exposed part, for example, the side wall of the resist pattern in FIG. 1, and the hardened layer is formed thick. When the reaction is completed, a hardened layer 4 is formed (FIG. 1 (f)). This hardened layer is a layer in which the resin physically adsorbed on the first resist surface has infiltrated not only into the resist surface but also into the inside of the resist, and as a result, the pattern shrinks. Finally, the unreacted composition for forming a fine pattern is removed by rinsing with a solvent to obtain a refined pattern (FIG. 1 (g)). Here, when the pretreatment described above is performed, it is considered that the basic compound supplied by the pretreatment composition contributes to the reaction between the resist and the resin as a catalyst. For this reason, a hardened layer becomes thicker compared with the case where pre-processing is not performed. In general, when the pretreatment composition is not used, when the cured layer is about 15 nm, the cured layer can be thickened up to about 3 times by pretreatment according to the present invention.

  As described above, by forming the hardened layer 4 mainly on the side wall of the resist pattern 2, specifically on the inner wall in the hole or trench, and on the outer wall in the line pattern, the width between the resist patterns is increased. As a result, the pitch size or the hole opening size of the resist pattern can be effectively miniaturized below the limit resolution.

  The radiation-sensitive resin composition that can be used for forming the resist pattern 2 may be any conventionally known and publicly used radiation-sensitive resin composition. Examples of the radiation-sensitive resin composition include a positive resist containing an alkali-soluble resin such as a novolak resin, a hydroxystyrene resin, an acrylic resin, and a quinonediazide compound, an acid generated by light irradiation, and a catalytic action of the generated acid Examples include chemically amplified positive or negative resists that form a resist pattern by using an acid, but the chemistry of generating a resist pattern by utilizing the catalytic action of the generated acid by light irradiation. An amplification type positive resist is preferable. Many resist materials have already been proposed and are commercially available, and any known or publicly available resist material may be used. Moreover, the resist pattern formation method using a radiation sensitive resin composition can use any conventionally known methods including a coating method, an exposure method, a baking method, a developing method, a developer, a rinsing method, and the like. .

  In the pattern forming method according to the present invention, the method for applying the composition for forming a fine pattern is, for example, a spin coating method, a spray coating method, or a dip coating method conventionally used when applying a radiation-sensitive resin composition. An appropriate method such as a roller coating method may be used. The applied coating layer is pre-baked as necessary to form a composition layer 3 for forming a fine pattern. The conditions for the heat treatment of the composition layer for forming a fine pattern are, for example, a temperature of 60 to 250 ° C., preferably 80 to 170 ° C., 10 to 300 seconds, preferably 60 to 120 seconds. It is preferably a temperature at which intermixing of the forming composition layer occurs. Here, if the temperature of the heat treatment is excessively high, the cured layer 4 becomes too thick and the space between the patterns may be buried, so care must be taken. The film thickness of the composition layer for forming a fine pattern to be formed can be appropriately adjusted depending on the temperature and time of heat treatment, the radiation sensitive resin composition used, the pretreatment composition, and the like. Therefore, these conditions may be set depending on how fine the resist pattern is to be made, in other words, how much the width of the resist pattern needs to be increased. However, the thickness of the coating layer is the thickness from the surface of the resist pattern, and is generally 0.01 to 100 μm.

  Furthermore, as a solvent used for the rinsing process that leaves the cured layer 4 formed by heating and removes the unreacted fine pattern forming composition layer 3, the solvent has a low solubility in the cured layer and is fine. A highly soluble composition is selected for the pattern forming composition. More preferably, the solvent used in the composition for forming a fine pattern is preferably used for the rinsing treatment.

  As mentioned above, although the example of the fine pattern formation method by this invention was demonstrated, it is also possible to form a finer pattern by applying this method. That is, since the hardened layer formed by the composition for forming a fine pattern used in the present invention is derived from polysilazane, it has relatively high mechanical strength and excellent etching resistance. For this reason, the pattern itself can be an independent pattern. An example will be described below.

The fine pattern forming method according to another embodiment Hereinafter, the pattern forming method according to another embodiment using the fine pattern forming method described above will be described in detail with reference to FIGS. 2 (a) to (h). It is as follows. FIGS. 2A to 2H are cross-sectional views in the direction perpendicular to the length direction of each pattern.

  First, a first convex pattern 104 having a convex portion is formed on the substrate 100 (FIG. 2A). Here, in the example shown in FIG. 2, the substrate 100 is formed by laminating a film 102 to be processed and an intermediate film 103 for processing assistance on a support 101. In the example described here, first, the processing auxiliary intermediate film 103 is processed into a fine pattern mask 501 according to one embodiment of the present invention, and the processed film 102 is further processed using the fine pattern mask 501. A method for forming a fine pattern 601 by processing such as etching will be described. However, the structure of the substrate is not limited to this example. Other structures of the substrate will be described later.

  The substrate shown in FIG. 2 is formed as follows. First, a film to be processed 102 that is finally processed into a pattern is formed on a support such as a silicon substrate or a glass substrate. At this time, in order to improve the adhesion of the film 102 to be processed on the surface of the support in advance, to improve the flatness of the support, and to improve the workability in the etching process, the intermediate for pretreatment A membrane (not shown) can also be provided. In such a case, the film 102 to be processed is formed on the support 101 through such a pretreatment intermediate film.

  In the present invention, any film 102 to be finally processed can be used depending on the purpose, and is not particularly limited. As the material of the film to be processed, (a) a conductive material such as aluminum (Al), aluminum silicide (AlSi), copper (Cu), tungsten (W), tungsten silicide (WSi), titanium (Ti), or nitride Titanium (TiN), etc. (b) Semiconductor material such as germanium (Ge) or silicon (Si), or (c) Insulating material such as silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride ( SiON) or organic materials such as organic resins.

  These materials are selected according to the intended use of the pattern. That is, the film to be processed which is a direct raw material of the pattern incorporated in the final semiconductor device or the like is processed into, for example, a metal wiring layer or an interlayer insulating film, and a material corresponding to the film is selected. For example, an inorganic or organic insulating material is used when the pattern is used as a trench isolation structure or a low dielectric insulating film, and a conductive material is used when a wiring structure is to be formed. Used. When an organic material is selected, for example, an organic material containing carbon atoms such as novolak, polyvinylphenol, polymethacrylate, polyarylene, polyimide, polyarylene ether, carbon, or the like is used.

  Next, a processing auxiliary intermediate film 103 is formed on the processing target film 102 as necessary. Hereinafter, the case where the processing auxiliary intermediate film is formed will be mainly described. However, when such a layer is not formed, the processing auxiliary intermediate film can be read as the film to be processed in the following description. This is because one of the most important features of the present invention is that a fine pattern mask derived from the resin composition is formed immediately above the film to be processed or, if present, the intermediate film for processing assistance. This is because the formation of the mask itself is substantially unaffected regardless of whether the mask is used to process the film to be processed or the processing auxiliary intermediate film.

  In the case of forming an intermediate film for processing assistance, this film may be the same as or different from the above-described pretreatment intermediate film that can be provided on the support 101. In addition, as a material for the processing auxiliary intermediate film, a conventionally known material such as an antireflection film can be used to provide the function. Further, when the processing aid intermediate film is used for a lower layer resist or the like used in the multilayer resist method, for example, it contains carbon atoms such as novolak, polyvinylphenol, polymethacrylate, polyarylene, polyimide, polyarylene ether, and carbon. Organic materials are used.

  When an organic material is used as the material for the processing auxiliary intermediate film, the carbon content is preferably 10 wt% or more. The reason is that if the carbon content is 10 wt% or more, the etching selectivity ratio with the layer formed by the resin composition to be described later, in other words, the difference in etching rate becomes large in the course of etching, and the processing is easy. Because it becomes. Moreover, although the film thickness of a process auxiliary film changes with uses, generally it is preferable to exist in the range of 20-10000 nm. The reason is that the purpose of the final pattern derived from the processing-assisting intermediate film may not be achieved at 20 nm or less, and at 10000 nm or more, there is a processing conversion difference in the process of transferring the spacer pattern described later to the film to be processed. This is because it occurs remarkably.

  Furthermore, a plurality of processing auxiliary intermediate films can be stacked in accordance with the type of the film to be processed and the processing auxiliary intermediate film and the etching conditions. In particular, when the processing auxiliary intermediate film 103 is provided on the film to be processed 102, the material of the processing auxiliary intermediate film is etched using a spacer portion formed of a resin composition described later as a mask, and the etching is performed. What functions as a mask when the film to be processed, which is a lower layer later, is further etched is preferable. In this case, the mask itself is a fine pattern mask having a fine pattern. In addition, without forming an independent film to be processed on the support, the intermediate film 103 for processing assistance is directly formed on the surface of the support and is processed to process the support surface as a film to be processed. A fine pattern mask is formed.

  Next, a first convex pattern 104 having convex portions is formed on the surface of the substrate 100 (FIG. 2A). The surface of the substrate 100 may be a processing assisting intermediate film 103 as shown in the figure, or may be a processing target film 102 or a support 101 itself, as will be described later. Specifically, the first convex pattern 104 can be formed by applying a resist (for example, a body-type chemically amplified resist) composition or the like, and exposing and developing by a usual method. However, the formation method of the 1st convex pattern 104 is not limited to it, It can also form by another method. For example, the first convex pattern 104 may be formed by forming a layer made of a material other than the resist composition and processing the layer by a lithography technique or the like.

  The radiation sensitive resin composition that can be used to form the first convex pattern 104 may be any conventionally known and publicly used radiation sensitive resin composition. Examples of the radiation-sensitive resin composition include a positive resist containing an alkali-soluble resin such as a novolak resin, a hydroxystyrene resin, an acrylic resin, and a quinonediazide compound, an acid generated by light irradiation, and the generated acid catalyst. Examples include chemically amplified positive or negative resists that form a resist pattern by using the action, but an acid is generated by light irradiation and the resist pattern is formed by using the catalytic action of the generated acid. A chemically amplified body type resist is preferred. Many resist materials have already been proposed and are commercially available, and any known or publicly available resist material may be used. Moreover, the resist pattern formation method using a radiation sensitive resin composition can use any conventionally known methods including a coating method, an exposure method, a baking method, a developing method, a developer, a rinsing method, and the like. .

  In order to finally form a fine pattern, the first convex pattern is preferably finer. For this purpose, it is preferable to use a method of forming a fine pattern using, for example, ArF or KrF as an exposure light source.

  The film thickness of the first convex pattern corresponds to the film thickness of the spacer portion described later. For example, when the film thickness of the processing auxiliary intermediate film 103 is in the range of 20 to 10000 nm, the film thickness of the spacer portion 401 described later is preferably in the range of 20 to 5000 nm. The thickness should be equivalent. The reason is that when the spacer 401 has a thickness of less than 20 nm, the spacer portion 401 serving as a mask is consumed in the process of etching the processing-assisting intermediate film 103, and the processing-assisting intermediate film 103 has a predetermined size. This is because it becomes difficult to process into a shape. On the other hand, if the film thickness of the first convex pattern 104 is reduced, the exposure amount margin, the focus margin, or the resolution at the time of exposure can be improved accordingly. Further, when the thickness of the spacer portion 401 is larger than 5000 nm, it is difficult not only to resolve the resist pattern as the first convex pattern itself but also to embed the resin composition itself. So be careful.

  A pretreatment composition is applied on the first convex pattern thus formed. The pretreatment composition used can be applied by the same method as described above using the same one as described above. In general, since it is generally difficult to apply the pretreatment composition only to the first convex pattern portion, the pretreatment composition is applied to the entire surface having the pattern. FIG. 2 (a) shows the case where the pretreatment composition forms the layer 105, but when the pretreatment composition does not have a film-forming component such as a polymer, a clear layer is not formed. Sometimes. After applying the pretreatment composition, it is also possible to combine heating or drying, and then washing unnecessary deposits by rinsing in the same manner as described above.

  Next, as shown in FIG. 2B, a composition for forming a fine pattern is applied so as to cover the first convex pattern 104 to form a coating layer 201. The composition for forming a fine pattern used here comprises the above-described resin comprising a repeating unit having a silazane bond.

  By applying and heating this composition for forming a fine pattern in the same manner as described above, the composition for forming a fine pattern in the vicinity of the first convex pattern is cured, and a cured layer 301 is formed. . Thereafter, the substrate is rinsed with a solvent to remove the uncured resin composition, thereby obtaining a pattern in which the first convex pattern is made fine by covering the first convex pattern with the cured layer 301. (FIG. 2 (c)).

  Here, as a solvent used for the rinsing process that leaves only the cured layer 301 formed by heating and removes the unreacted resin composition, the solvent has low solubility in the cured layer, and the resin composition On the other hand, one having high solubility is selected. More preferably, the solvent used in the resin composition is used for the rinse treatment.

  Next, the hardened layer formed on the first convex pattern is processed to form a layer made of a material different from the substance constituting the first convex pattern on the side wall of the convex portion of the first convex pattern. Let Such a layer is hereinafter referred to as a spacer for convenience. In order to form this spacer, it is necessary to selectively remove the hardened layer covering the upper surface of the first convex pattern. In this case, the selective etching method is not particularly limited as long as the spacer can be finally formed. For example, a wet etching method after protecting the hardened layer side wall portion with any filling agent, or a dry ion etching method, a reactive ion etching method, a magnetron type reactive ion etching method, an electron beam ion etching method, Examples thereof include a dry etching method such as an ICP etching method or an ECR ion etching method. As described above, the hardened layer forms a compound with other elements around Si. Therefore, when a dry etching method is used, it is preferable to use a source gas containing fluorine atoms (F).

  In addition, a hardened layer may be formed on the embedded bottom surface, that is, the surface of the substrate, which is a portion other than the above-described convex patterns and spacers. Although it is possible to prevent the cured layer from being formed on the embedded bottom surface by adjusting the application method of the resin composition and the curing conditions, generally, the cured layer is also formed on the embedded bottom surface. In such a case, it is also necessary to remove it. The removal of the hardened layer on the bottom surface of the embedding is relatively simple and preferably performed at the same time as the removal of the hardened layer above the convex portion of the convex pattern. In this case, by adjusting the etching conditions, the hardened layer on the upper side of the convex portion and the embedded bottom surface is simultaneously removed. However, the removal of the hardened layer formed on the bottom surface of the embedding can be performed at any stage before etching the film to be processed using a fine pattern mask, specifically, above the convex portion of the first convex pattern. Before removing the cured layer, it can be performed simultaneously with the removal of the first convex pattern described later. However, in the case where the processing auxiliary intermediate film 103 exists, it is necessary to remove the cured film before etching it.

  By such processing, a layer (spacer) 401 made of a material different from the material constituting the first convex pattern is formed on the side wall of the convex portion of the first convex pattern, and the second convex pattern (FIG. 2) is formed. (D)) is formed. Here, in the present invention, since the pretreatment composition is applied before applying the fine pattern forming composition, the curing reaction of the fine pattern forming composition is promoted, and the cured layer 301 becomes thick. For this reason, the width of the spacer 401 is increased. In other words, the width of the spacer 401 can be controlled by changing the pretreatment composition without changing the resist pattern or the composition for forming a fine pattern.

  Next, by using a dry etching method, the first convex pattern 104 is removed to form a mask layer made of only the spacer 401 (not shown), and further, a spacer in the processing auxiliary intermediate film 103 is etched. The part not covered with 401 is removed. That is, the processing assisting intermediate film 103 is etched using the second convex pattern of the spacer 401 as a mask to form a pattern 501 derived from the processing assisting intermediate film (FIG. 2E). Here, the removal of the first convex pattern and the removal of the processing auxiliary intermediate film or the film to be processed can be performed independently by adjusting the etching conditions, or can be performed simultaneously or continuously under a single condition. It can also be done. Here, when the etching conditions are adjusted and the process is terminated at the stage where only the first convex pattern is removed, a mask layer made of only the spacer 401 can be obtained. In the pattern 501, when the first convex pattern 104 formed in the initial stage is line and space, spacers are formed as line patterns on both sides of each line. Therefore, considering the number of line patterns, twice as many patterns are formed. Therefore, it can be said that such a method is a method of doubling the pattern.

  Prior to the etching for forming the pattern 501, it is preferable to embed a resin or the like in the space between the first convex patterns. That is, in the etching process, a part of the side wall of the second convex pattern is exposed, and the width may be narrowed due to the etching effect. Therefore, it is preferable to protect the second convex pattern by embedding resin. . Such a resin can be arbitrarily selected from various resins, but an organic material having an etching selectivity equivalent to that of the first convex pattern is preferable. As such an organic substance, for example, polyvinyl pyrrolidone or the like dissolved in a solvent can be mentioned.

  In this case, the dry etching method is not particularly limited as long as the processing auxiliary intermediate film 103 can be processed. For example, a reactive ion etching method, a magnetron type reactive ion etching method, an electron beam ion etching method, an ICP etching method, or an ECR ion etching method can be appropriately selected. As the source gas, it is preferable to use a gas containing at least one of the group consisting of an oxygen atom (O), a nitrogen atom (N), a chlorine atom (Cl), and a bromine atom (Br). For an etchant obtained by discharging using a gas containing these atoms, a compound having a bond between an inorganic element and oxygen is inactive, and thus preferably acts on the spacer portion.

For this reason, it becomes possible to etch the intermediate film for processing 103 with good anisotropy. The etching gas containing oxygen atoms is O ₂ , CO, CO ₂ , the etching gas containing nitrogen atoms is N ₂ , NH ₃ , the etching gas containing chlorine atoms is Cl ₂ , HCl, BCl ₃ , or Examples of the etching gas containing bromine atoms include HBr and Br ₂ . These etching gases may be mixed and used. Furthermore, the etching gas may contain sulfur atoms (S) because the film to be processed can be processed with good anisotropy. In addition, a gas such as argon (Ar) or helium (He) may be included.

  After the pattern 501 is formed, the spacer 401 remaining on the pattern 501 is removed as necessary (FIG. 2F). As a result, a fine pattern that can be used as a mask for processing the film to be processed 102 is formed. Further, when the processing auxiliary intermediate film is not formed, a fine pattern is formed by processing the processed film. In this case, for example, in the case of a wet etching method or a dry etching method, a dry method such as a reactive ion etching method, a magnetron type reactive ion etching method, an electron beam ion etching method, an ICP etching method, or an ECR ion etching method is used. An etching method is mentioned. As described above, the hardened layer forms a compound with other elements around Si. Therefore, when a dry etching method is used, it is preferable to use a source gas containing fluorine atoms (F). However, since the film to be processed 102 is exposed in space, a method that does not damage the film to be processed needs to be selected from the above method group.

  Next, the film to be processed 102 is processed using the pattern 501 as an etching mask. As the processing method of the film to be processed, for example, a wet etching method or a dry etching method can be used, and more specifically, a reactive ion etching method, a magnetron type reactive ion etching method, an electron beam ion etching method, or the like. And dry etching methods such as an ICP etching method or an ECR ion etching method. It is common to select an etchant according to the material of the film to be processed.

  By processing such a film to be processed, a fine pattern 601 made of the film to be processed is formed (FIG. 2G), and the pattern 501 remaining as a mask is further removed as necessary.

  In the above description, a method of forming a fine pattern using a substrate on which a film to be processed and an intermediate film for processing support are formed on a support and using a fine pattern mask directly formed thereon is described. . However, the method according to the present invention is not limited thereto, and a substrate composed only of a support or a substrate having a film to be processed on the support but not having an intermediate film for processing assistance can be used. In either case, a fine pattern can be formed by processing the surface of the substrate, in other words, the film immediately below the first convex pattern or the surface portion of the support by the method of the present invention. . Also, a plurality of processing auxiliary intermediate films are laminated, and the uppermost layer, that is, the film immediately below the first convex pattern is processed by the method of the present invention to form a fine pattern mask. It is also possible to form the next pattern mask by processing the next processing auxiliary intermediate film directly underneath by etching or the like. In other words, the surface of the substrate is processed by the method of the present invention, but the obtained fine pattern can also be used as a pattern mask for forming another fine pattern corresponding to the pattern.

  Further, for example, an independent fine pattern mask is formed by processing a substrate in which a processing support intermediate film 103 is formed on a transparent support such as a bare glass substrate by the method according to the present invention, and further preparing it separately. A pattern is formed by performing so-called contact exposure, which is performed by adhering to a resist film formed on the insulating material film or conductive material film formed, or a fine pattern formed on the substrate according to the above-described method. It is also possible to transfer the pattern mask onto a separately prepared insulating material film or conductive material film and then perform etching through the pattern mask to form a pattern. In other words, the surface of the substrate is processed by the method of the present invention, but the obtained fine pattern can also be used as a pattern mask for forming another fine pattern corresponding to the pattern.

Still another fine pattern forming method The fine pattern forming method according to another embodiment described above forms a pattern using the spacer formed on the side wall of the convex portion of the first convex pattern as a mask. The fine pattern forming method according to still another embodiment forms a pattern by removing the spacer and the lower layer of the spacer. Another embodiment of the present invention will be described in detail with reference to FIGS. 3A to 3H.

  First, a spacer is formed on the side wall of the convex portion of the first convex pattern in the same manner as in the fine pattern forming method according to the other embodiment (FIGS. 3A to 3D). The steps so far are the same as the basic fine pattern forming method described above.

  Next, a material 104A equivalent to the first convex pattern is embedded in the space between the first convex patterns. (FIG. 3 (e)). Since the space portion between the first convex patterns is miniaturized by the spacer 401, the space between the spacers substantially becomes the space portion.

  The material equivalent to the first convex pattern embedded in the space between the first convex patterns is preferably the same as that used to form the first pattern. For example, when the first convex pattern is formed with a resist resin or the like, it is preferable that the resist composition used for forming the first convex pattern is filled in the space portion and cured. However, the material embedded in the space portion later forms a compensation pattern for the first convex pattern. In other words, the material embedded in the space portion forms an additional convex portion with respect to the first convex pattern. That is, when forming a final fine pattern, it is necessary to function as a mask material similar to the first convex pattern. Accordingly, the material equivalent to the first convex pattern here is not necessarily the same as the material used to form the first convex pattern, and is the same mask material as the first convex pattern. And can be etched or removed in the same manner as the first convex pattern.

  In order to function as a mask material for forming a final fine pattern, it is preferable that the thickness of the material layer embedded in the space portion has a thickness equivalent to that of the first convex pattern. For this reason, when embedding is performed, it is preferable to embed up to the same height as the first convex pattern. Moreover, after embedding to the height more than a 1st convex pattern, it can also planarize by performing an etching process etc. until it becomes the height equivalent to a 1st convex pattern. In FIG. 3 (e), the height of the embedded material 104A is shown as a different height to distinguish it from the first convex pattern 104, but it is preferable that the difference in height is small. .

  Subsequently, the spacer 401 is removed by the same method as described in the first fine pattern forming method (FIG. 3F). Thus, a mask for etching the film to be processed 102 or the processing auxiliary intermediate film 103 is formed. This mask is composed of the first convex pattern 104 and a compensation pattern 104A corresponding thereto. The opening or groove of the pattern mask is a portion where the spacer 401 is present. In the present invention, the thickness of the cured layer 301 can be adjusted by using the pretreatment composition. For this reason, the width of the spacer 401 can also be adjusted. Therefore, in this embodiment, the mask opening system or groove width can be adjusted by the pretreatment composition.

  A fine pattern mask for processing the processing target film 102 by processing the processing auxiliary intermediate film 103 using the mask composed of the first convex pattern 104 and the compensation pattern 104A corresponding thereto (FIG. 3G). To form. Further, the processed film 102 is processed using the patterned processing auxiliary intermediate film 103 as a mask (FIG. 3H). Thereby, a fine pattern having a groove corresponding to the spacer 401 can be obtained.

  As described above, the method for forming a fine pattern of the present invention is required to include the steps specified in the present invention, but otherwise known methods can be combined. Therefore, when a resist pattern is used for the first convex pattern, the photoresist used for forming the resist pattern, and the resist forming method using the photoresist are the conventional photoresist and the conventionally known resist forming method. Any one may be used. In addition, the resist pattern can use the arbitrary thing generally used. On the other hand, the first convex pattern can be a convex pattern after etching the lower layer using the photoresist after the fine pattern is formed as an etching mask.

  The present invention will be described below with reference to various examples.

Preparation Example First, polysilazane manufactured by AZ Electronic Materials was dissolved in dibutyl ether at a concentration of about 10% by weight and filtered through a 0.05 micron filter to prepare a polysilazane composition (composition for forming a fine pattern). did.

  Next, a pretreatment composition as shown in Table 1 was prepared. Pure water was used as a solvent, and a pretreatment composition was prepared by dissolving each component. Vinyl acetate / vinyl alcohol copolymer and vinyl imidazole / vinyl pyrrolidone copolymer are those manufactured by AZ Electronic Materials, polyethyleneimine is manufactured by Kanto Chemical Co., and polyallylamine is manufactured by Sigma-Aldrich. Using.

Comparative Examples 1-3 and Examples 1-30
KrF resist DX5250P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was spin-coated on the substrate, and then exposed by a normal method to form a line and space pattern (line width 180 nm) with a pitch of 1: 5. Next, as shown in Table 1, the pretreatment composition was not applied to the surface of the pattern, or the pretreatment composition was applied and baked. Baking was performed under the conditions shown in Table 1.

  Thereafter, each substrate was rinsed with pure water for 60 seconds and then spin-dried. Furthermore, after applying the polysilazane composition to the substrate, it was baked at 90 ° C./60 seconds, rinsed with dibutyl ether for 60 seconds, and then spin-dried to obtain samples of Examples 1 to 30.

  Further, a sample in which a resist pattern was formed in the same manner as in Example 1 was used as a sample of Comparative Example 1. Furthermore, as shown in Table 1, the sample of Comparative Example 1 was baked after the pretreatment composition was applied to the surface of the pattern, and Samples of Comparative Examples 2 and 3 were obtained. The polysilazane composition was not applied to the samples of Comparative Examples 1 to 3.

  The obtained pattern was subjected to before and after pattern refining treatment using a polysilazane composition using a side scanning electron microscope (S-9200 (trade name), manufactured by Hitachi High-Technologies Corporation). The dimension of the subsequent line was measured, and the amount of increase in pattern width was calculated.

  Further, using a dry etcher (NE5000N (trade name) manufactured by ULVAC, Inc.), the film thickness difference before and after etching with respect to the patterns of Examples 1 to 30 and Comparative Examples 1 to 3 was measured. The ratio when the film thickness difference between before and after was set to 1 was calculated, and dry etching resistance was evaluated.

  The obtained results were as shown in Table 1.

  From the results in Table 1, by covering the pattern with the polysilazane composition, the pattern width is increased and the pattern is made finer. However, when the pretreatment composition is used, the nitrogen-containing base is used. It was found that the amount of increase in the pattern width increases when the organic compound is included, and the dry etching resistance is improved when the basic polymer is included.

Comparative Example 4 and Examples 31-36
ArF resist AX3110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was spin-coated on the substrate, and then exposed by a normal method to form a trench pattern (trench width 120 nm) with a pitch of 1: 1 (Comparative Example). 4). Next, a pretreatment composition as shown in Table 2 was prepared. Pure water was used as a solvent, and a pretreatment composition was prepared by dissolving each component. Next, as shown in Table 2, the pretreatment composition was not applied to the surface of the pattern, or the pretreatment composition was applied. Further, after applying the polysilazane composition to the substrate, it was baked at 90 ° C. for 60 seconds, rinsed with dibutyl ether for 60 seconds, and then spin-dried.

  The obtained pattern was processed before and after pattern refining using a polysilazane composition using a side-long scanning electron microscope (S-9200 (trade name), manufactured by Hitachi High-Technologies Corporation). The dimension of the subsequent trench was measured, and the increase amount of the pattern width was calculated.

  The obtained results were as shown in Table 2.

  From the results in Table 2, it was found that the pattern width increase amount was increased by increasing the concentration of the nitrogen-containing basic compound.

Comparative Example 5 and Example 38
ArF resist AX3110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was spin-coated on the substrate, and then exposed by a normal method to form a trench pattern with a pitch of 1: 1. Next, a pretreatment composition in which tetramethylammonium hydroxide was dissolved in pure water at a concentration of 0.01% by weight was applied to the surface of the pattern. Further, after applying the polysilazane composition to the substrate, it was baked at 90 ° C. for 60 seconds, rinsed with dibutyl ether for 60 seconds, and then spin-dried.

Further, the cured layer derived from the polysilazane composition formed on the upper surface of the pattern was removed by dry etching (NE5000N (trade name), manufactured by ULVAC, Inc.) using CF ₄ as an etching gas. Further with O ₂ gas, by removing the pattern from the resist to form a second convex pattern composed of siliceous derived from polysilazane composition (Example 20). The pattern width of this convex pattern was 50 nm, and there was no pattern collapse.

  On the other hand, a second convex pattern was formed in the same manner as in Example 20 except that the pretreatment composition was not applied and baking was performed immediately thereafter (Comparative Example 5). Although the second convex pattern was obtained, the width of the obtained pattern was too narrow, and pattern collapse was observed.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Resist film 3 Fine pattern formation composition layer 4 Hardened layer 5 Pretreatment composition layer 6 Adsorption resin 100 Substrate 101 Support body 102 Processed film 103 Intermediate film 104 First convex pattern 104A Embedding material 105 Pretreatment composition Physical layer 201 Coating layer 301 Hardened layer 401 Spacer 501 Pattern 601 derived from intermediate film Fine pattern

Claims (15)

Forming a first convex pattern having convex portions on the surface of the substrate;
An application step of applying a resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern, and a solvent that dissolves the resin and does not dissolve the convex pattern,
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
The step of rinsing the substrate after the curing step to remove the uncured resin composition, and removing the cured layer formed on the upper surface of the convex portion, the first on the side wall of the convex portion A method of forming a fine pattern, comprising a step of forming a layer made of a substance different from the substance constituting the convex pattern.   The method for forming a fine pattern according to claim 1, further comprising a pretreatment step of applying a pretreatment composition comprising a basic compound before the coating step.   The fine pattern forming method according to claim 1, wherein the basic compound is selected from the group consisting of nitrogen-containing basic compounds. The fine pattern forming method according to claim 3, wherein the nitrogen-containing basic compound is represented by the following general formulas (A) to (C):

(Wherein R ^{a to} R ^d are each independently a group selected from the group consisting of hydrogen, a saturated hydrocarbon group having 1 to 4 carbon atoms, and an alkanol group having 1 to 4 carbon atoms, or R ^{two of a to} R ^d are bonded by a covalent bond to form a carbocycle having 2 to 5 carbon atoms, an oxygen-containing carbocycle, or a nitrogen-containing carbocycle, provided that the formulas (A) and (B) R ^{a to} R ^d are not hydrogen at the same time, and n is a number from 1 to 3.)   The fine pattern forming method according to claim 3 or 4, wherein the nitrogen-containing basic compound is a primary amine or a secondary amine.   The nitrogen-containing basic compound is ethylenediamine, propylenediamine, piperidine, piperazine, hydroxyethylpiperazine, ethanolamine, isopropanolamine, diethanolamine, N-methylethanolamine, N-ethylethanolamine, N, N-dimethylethanolamine, N Or N-diethylethanolamine, 2- (2-aminoethylamino) ethanol, morpholine, tetramethylammonium hydroxide, and tetraethylammonium hydroxide according to any one of claims 3-5. The fine pattern forming method described.   The fine pattern forming method according to claim 2, wherein the basic compound is a basic polymer.   The fine pattern forming method according to claim 7, wherein the basic polymer contains vinylimidazole, ethyleneimine, vinylamine, allylamine, or a mixture thereof as a polymerization unit. The fine pattern forming method according to claim 1, wherein the repeating unit having the silazane bond is represented by the following formula (I).

Wherein R ^{1 to} R ³ are each independently selected from the group consisting of hydrogen, a C 1-6 saturated hydrocarbon group, and a silazane group having a C 1-6 saturated hydrocarbon group. Group.)   The resist pattern according to any one of claims 1 to 9, wherein the resist pattern is formed from a photoresist or is formed by an etching process using a pattern formed from a photoresist as a mask. The fine pattern forming method described. Forming a first convex pattern having convex portions on the surface of the substrate;
A pretreatment step of applying a pretreatment composition comprising a basic compound on the first convex pattern;
An application step of applying a resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern;
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
Removing the uncured resin composition by rinsing the substrate after the curing step;
Removing the hardened layer formed on the upper surface of the convex part to form a layer made of a substance different from the substance constituting the first convex pattern on the side wall of the convex part; and A method of forming a fine pattern comprising the step of forming a fine second convex pattern made of the different kind of material by removing the portion. Forming a first convex pattern having convex portions on the surface of the substrate;
A step of applying a pretreatment composition comprising a basic compound on the first convex pattern. A resin composition comprising a resin comprising a repeating unit having a silazane bond on the first convex pattern. Coating process to apply,
A curing step of heating the substrate after the coating step and curing the resin composition present in a portion adjacent to the convex portion;
Removing the uncured resin composition by rinsing the substrate after the curing step;
Removing a hardened layer formed on the upper surface of the convex part to form a layer made of a substance different from the substance constituting the first convex pattern on the side wall of the convex part;
The step of embedding a material equivalent to the first convex pattern in the space portion to form a compensation pattern for the first convex pattern, and removing the layer made of the different kind of substance, A method of forming a fine pattern comprising a step of forming a fine pattern comprising a pattern and a compensation pattern for the first convex pattern.   A method for forming a fine pattern, comprising processing the surface of the substrate by using the fine pattern formed by the method according to claim 11 or 12 as a mask to form a further fine pattern.   The method for forming a fine pattern according to claim 13, wherein the substrate has a film to be processed formed on a support, and the surface is the film to be processed.   14. The method for forming a fine pattern according to claim 13, wherein the substrate is a substrate on which a film to be processed and an intermediate film for processing assistance are formed, and the surface is the intermediate film for processing assistance.

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