JP5661562B2 - Fine pattern mask, method of manufacturing the same, and method of forming fine pattern using the same - Google Patents

Description

  The present invention relates to a pattern forming method, in particular, a method for forming a pattern on a substrate in the manufacture of a semiconductor device, and a method for forming a pattern mask used for the pattern formation.

  In general, in the process of manufacturing a semiconductor device, a film to be processed (eg, insulating film, conductive film) is formed on a substrate, an etching mask is formed on the upper layer, and then a predetermined film is formed by etching. The step of forming a pattern of the size and shape is performed a plurality of times.

  In the process of forming a pattern on a film to be processed, a lithography material that uses a photosensitive material called a photoresist (hereinafter sometimes referred to as “resist”) and performs a so-called exposure process, development process, and the like is generally used. It is done.

  On the other hand, in the recent field of semiconductor devices, there is a high need for higher density or higher integration, and miniaturization of resist patterns is also required to meet the needs. In order to miniaturize the resist pattern, it is necessary to improve the lithography technique, and studies on an exposure light source, a resist material, or an exposure method are underway. Examples of such a technique include use of an ArF excimer laser as a light source and immersion exposure. However, the line width of the resist pattern that can be formed by these methods is about 40 nm, and it is difficult to achieve a line width narrower than that. Against this background, various proposals have been made to achieve higher resolution patterns.

  For example, Non-Patent Document 1 discloses that a spacer is formed on a sidewall of a patterned template formed on a film to be processed by a chemical vapor deposition method (hereinafter referred to as a CVD method), and etching is performed using the spacer as a mask. A method for obtaining a fine pattern is disclosed. This method is performed according to the following procedure. A resist pattern is formed on the previously formed template layer by a photoresist process. An image is transferred to the template layer using the resist pattern as a mask to form a convex (patterned template layer). Further, a spacer is formed on the convex side wall by a CVD method. Then, the spacer remains as a pattern by peeling off the protrusions. At this time, if the patterned template layer is in a line shape, two patterns made of spacers are formed for one initial line. That is, pattern duplication is achieved. By processing the film to be processed using the doubled pattern as an etching mask, a fine pattern is formed. In Non-Patent Document 1, this method has succeeded in forming a fine pattern of 22 nm. However, the CVD method for achieving this method requires a considerable amount of time for the process, and there is a high need for improvement from the viewpoint of mass productivity. Further, since the CVD method needs to be performed under a high temperature condition, there is a problem that it is difficult to directly apply to the surface of a resist pattern having low heat resistance. For this reason, since a template creation process is required, the process becomes complicated and the cost tends to increase.

  Also known is Plasma Enhanced Atomic Layer Deposition. This method is a method that is relatively similar to the CVD method, but has a feature that it can be performed under low temperature conditions. However, the film growth rate is slow and there is room for improvement in terms of mass productivity.

  Further, a method for forming a fine pattern by applying a polysilazane composition to a substrate surface without using CVD has been studied (Patent Document 1). In this method, for example, a silicon-containing spacer derived from polysilazane is formed on the side surface of the convex portion of the resist pattern, and then the resist pattern is removed. As a result, considering the line-shaped resist pattern, silicon-containing spacers are formed on both sides of the line, and as a result, the pattern can be doubled. This method is characterized by lower costs and higher mass productivity than the CVD method described above. However, according to the study by the present inventors, there is room for improvement in the line edge roughness (hereinafter sometimes referred to as LER) of the obtained pattern. In addition, since the thickness of the silicon-containing spacer formed on the side surface of the resist pattern convex portion becomes the line width of the final pattern, advanced film thickness control is required, but the method described in Patent Document 1 compares Since it is difficult to control the film thickness, it is desirable to use a method that allows easier film thickness control. Further, when a thick film having a thickness exceeding 15 nm is formed, there is room for improvement since the rectangularity of the formed spacer tends to be insufficient.

International Publication No. 2009/096371

Chris Bencher, Nanochip technology journal, issue of two 2007

  An object of the present invention is to provide a resin composition capable of forming a fine pattern mask having excellent line edge roughness, uniform film quality, and a pattern forming method using the same.

（式中、Ｒ^１、およびＲ^２はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、またはこれらの基以外であってケイ素に連結する原子が炭素である基であり、
Ｒ^３は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、または炭素数１〜６の飽和炭化水素基を有するシラザン基であり、
Ｒ^１、Ｒ^２およびＲ^３はのうちの少なくとも一つは水素原子であり、
ｍは重合度を示す数である。）
で示される繰り返し単位を有するポリマー、および下記一般式（Ｉｂ）：

（式中、Ｒ^４は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、またはこれらの基以外であってケイ素に連結する原子が炭素である基であり、
ｎは重合度を示す数である。）
で示される繰り返し単位を有するポリマーからなる群から選択されるケイ素含有ポリマーと、
下記一般式（ＩＩ）：

（式中、Ｒ^５およびＲ^６はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、または炭素数５〜７のシクロアルキル基であり、
Ｒ^７およびＲ^８はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、炭素数５〜７のシクロアルキル基、または炭素数６〜１０のアリール基であり、
ｐは重合度を示す数である。）
で示される繰り返し単位を１種類以上有するケイ素非含有有機ポリマーと、
溶剤と、
を含んでなることを特徴とするものである。 The composition for forming a fine pattern according to the present invention has the following general formula (Ia):

Wherein R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or 6 to 10 carbon atoms. An aryl group, an alkylsilyl group having 1 to 6 carbon atoms, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an atom connected to silicon other than these groups is carbon Group,
R ³ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkyl having 1 to 6 carbon atoms. A silazane group having a silyl group, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a saturated hydrocarbon group having 1 to 6 carbon atoms,
At least one of R ¹ , R ² and R ³ is a hydrogen atom;
m is a number indicating the degree of polymerization. )
And a polymer having a repeating unit represented by the following general formula (Ib):

(Wherein R ⁴ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 1 carbon atom) An alkylsilyl group having 6 to 6 carbon atoms, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a group other than these groups, wherein the atom connected to silicon is carbon,
n is a number indicating the degree of polymerization. )
A silicon-containing polymer selected from the group consisting of polymers having a repeating unit represented by:
The following general formula (II):

(Wherein R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 5 to 7 carbon atoms,
R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or an aryl group having 6 to 10 carbon atoms,
p is a number indicating the degree of polymerization. )
A silicon-free organic polymer having at least one repeating unit represented by:
Solvent,
It is characterized by comprising.

In addition, a method for forming a fine pattern mask according to the present invention includes:
A step of preparing a base material on which a film to be processed is laminated,
Forming a first convex pattern having a convex portion on the film to be processed;
An application step of applying the resin composition 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 or plasma treatment of 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 mask made of the different kind of material by removing the portion.

Another method for forming a fine pattern mask according to the present invention is as follows.
A step of preparing a base material in which a film to be processed and an intermediate film for processing are sequentially laminated on the surface;
Forming a first convex pattern having a convex portion on the processing-assisting intermediate film;
An application step of applying the resin composition 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 or plasma treatment of 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;
Removing the first convex portion to form a fine second convex pattern mask made of the different kind of substance, and forming the processing-assisting intermediate film via the second convex pattern mask. The method includes a step of forming a fine pattern mask for processing a film to be processed by etching.

Another method for forming a fine pattern mask according to the present invention is as follows.
A step of preparing a base material on which a film to be processed is laminated,
Forming a first convex pattern having a convex portion on the film to be processed;
An application step of applying the resin composition 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 or plasma treatment of 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;
By embedding a material equivalent to the first convex pattern in the space portion, forming a compensation pattern for the first convex pattern, and removing the layer made of the different material, the first convex pattern The method includes a step of forming a fine pattern mask including a pattern and a compensation pattern for the first convex pattern.

Another method of forming a fine pattern mask according to the present invention is as follows.
A step of preparing a base material in which a film to be processed and an intermediate film for processing are sequentially laminated on the surface;
Forming a first convex pattern having a convex portion on the processing-assisting intermediate film;
An application step of applying the resin composition 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 first convex pattern;
Removing the uncured resin composition by rinsing or plasma treatment of 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;
Embedding a material equivalent to the first convex pattern into the space between the convex parts, and forming a compensation pattern for the first convex pattern;
The step of forming a fine pattern consisting of the first convex pattern and a compensation pattern for the first convex pattern by removing the layer made of the different kind of substance, and the first convex pattern and the The process assisting intermediate film is etched through a filling pattern for the first convex pattern to form a fine pattern mask for processing the film to be processed.

  The fine pattern mask according to the present invention is formed by any one of the methods described above.

  Furthermore, the method for forming a fine pattern according to the present invention includes a step of etching the film to be processed using the fine pattern mask as an etching mask.

  ADVANTAGE OF THE INVENTION According to this invention, the composition for fine pattern formation which can be used for the fine pattern formation method which is excellent in mass productivity and whose spacer width is easy to control is provided. According to this method, twice the number of patterns can be formed with a fine size compared to a pattern formed by a normal method, and the LER is excellent and the rectangularity of the formed spacer is high. It has the characteristics.

The schematic diagram explaining the 1st embodiment of the formation method of the fine pattern by this invention. The schematic diagram explaining the 2nd embodiment of the formation method of the fine pattern by this invention.

Resin composition

  The resin composition according to the present invention comprises a silicon-containing polymer, a silicon-free organic polymer, and a solvent capable of dissolving them.

式中、Ｒ^１、およびＲ^２はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、またはこれらの基以外であってケイ素に連結する原子が炭素である基であり、
Ｒ^３は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、または炭素数１〜６の飽和炭化水素基を有するシラザン基であり、
Ｒ^１、Ｒ^２およびＲ^３はのうちの少なくとも一つは水素原子であり、
ｍは重合度を示す数である。

式中、Ｒ^４は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルケニル基、炭素数５〜７のシクロアルキル基、炭素数６〜１０のアリール基、炭素数１〜６のアルキルシリル基、炭素数１〜６のアルキルアミノ基、炭素数１〜６のアルコキシ基、またはこれらの基以外であってケイ素に連結する原子が炭素である基であり、
ｎは重合度を示す数である。 First, the silicon-containing polymer is selected from the group consisting of a polymer having a repeating unit represented by the following general formula (Ia) and a polymer having a repeating unit represented by the following general formula (Ib).

Wherein, ^{R 1,} and ^{R 2} are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, cycloalkyl group having 5 to 7 carbon atoms, 6 to 10 carbon atoms An aryl group, an alkylsilyl group having 1 to 6 carbon atoms, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a group other than these groups, wherein the atom connected to silicon is carbon And
R ³ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkyl having 1 to 6 carbon atoms. A silazane group having a silyl group, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a saturated hydrocarbon group having 1 to 6 carbon atoms,
At least one of R ¹ , R ² and R ³ is a hydrogen atom;
m is a number indicating the degree of polymerization.

In the formula, R ⁴ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 1 to 1 carbon atom. An alkylsilyl group having 6 carbon atoms, an alkylamino group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a group other than these groups, wherein the atom connected to silicon is carbon,
n is a number indicating the degree of polymerization.

The resin represented by the above formula (Ia) 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 (Ia). Moreover, the repeating unit represented by the said formula (Ia) 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 (Ia), all of R ^{1 to} R ³ are hydrogen. The other perhydropolysilazane has-(SiH ₂ NH)-and-(SiH ₂ N) <as repeating units, and the terminal is hydrogen or mono-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 resin represented by the above formula (Ib) is generally called polysilsesquioxane. This polysilsesquioxane has a network-like three-dimensional structure in which three out of four bonds of one silicon atom are bonded to other silicon atoms through oxygen. Two or more kinds of repeating units represented by the above formula (Ib) can be combined.

  These silicon-containing polymers can be combined with repeating units composed of other hydrocarbons, repeating units having a siloxane bond, and the like as long as the effects of the present invention are not impaired.

  The molecular weight of such a silicon-containing polymer is arbitrarily selected according to the type of resist to be applied, the type of target pattern, etc., but is preferably 500 to 100,000 in terms of weight average molecular weight, It is preferable that it is 600-10,000. In the present invention, the weight average molecular weight is a value calculated by creating a calibration curve using gel permeation chromatography with polystyrene as a standard.

式中、Ｒ^５およびＲ^６はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、または炭素数５〜７のシクロアルキル基であり、
Ｒ^７およびＲ^８はそれぞれ独立に水素原子、炭素数１〜６のアルキル基、炭素数５〜７のシクロアルキル基、または炭素数６〜１０のアリール基であり、
ｐは重合度を示す数である。 Further, the silicon-free organic polymer used in the present invention is selected from the group consisting of polymers having one or more repeating units represented by the following general formula (II).

In the formula, R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 5 to 7 carbon atoms,
R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or an aryl group having 6 to 10 carbon atoms,
p is a number indicating the degree of polymerization.

  Here, even if the silicon-free organic polymer is a homopolymer containing only one type of repeating unit represented by the general formula (II), it contains two or more types of repeating units represented by the general formula (II). A copolymer may also be used.

  Among such non-silicon-containing organic polymers, preferred are homopolymers such as polystyrene, polyethylene, polypropylene, α-methylstyrene, poly (styrene-co-α-methylstyrene), poly (styrene-co-ethylene). ) And the like. These polymers are preferable because they have a low affinity with a resist and can form a more uniform and highly rectangular pattern.

  The molecular weight of such a silicon-free organic polymer is arbitrarily selected according to the type of resist to be applied, the type of target pattern, and the like, but the weight average molecular weight may be 500 to 400,000. Preferably, it is 900-350,000.

  The resin composition according to the present invention comprises the above silicon-containing polymer (Ia) or (Ib) and a silicon-free organic polymer (II). These compounding ratios are adjusted according to the intended use and shape of the pattern. For example, process control is easier when the silicon-containing polymer is smaller, and the rectangularity of the resulting pattern tends to be better, and line edge roughness tends to be improved as the silicon-containing polymer is larger. Specifically, the blending ratio of the silicon-containing polymer and the silicon-free organic polymer is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, by weight. .

  The resin composition according to the present invention generally comprises a solvent. This solvent needs to be capable of dissolving each of the above polymers. That is, when the composition is applied to the substrate surface, 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, if an organic resist pattern is formed on the surface of the substrate, the resist pattern will be destroyed before the pattern is refined if the solvent dissolves the pattern when applied on the resist pattern. Must not dissolve. Furthermore, it is preferable that the resist pattern does not react.

  As the solvent that can be used in the present invention, any solvent can be selected as long as it satisfies the above conditions. Moreover, it can select according to the kind of polymer 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, 1-pentane, n-hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, n-nonane, i-nonane, n-decane, i- (C) unsaturated hydrocarbons such as cyclohexene and dipentene (limonene), (d) ketones such as methyl isobutyl ketone (MIBK), such as decane, ethylcyclohexane, methylcyclohexane, cyclohexane and P-menthane ), (E) aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, Ethylbenzene, trimethylbenzene, and triethylbenzene like, and the like. Among these, preferred is a solvent selected from the group consisting of (a) ethers and (b) saturated hydrocarbons. More specifically, dibutyl ether and decalin are organic photopolymers having a first convex pattern. In the case of a resist, even if the kind of resin or resist material changes, it can be widely applied and is a preferable solvent. These solvents can be used in combination of two or more as required.

  The resin composition according to the present invention is obtained by dissolving the polymer in the solvent, but the concentration is not particularly limited. However, it can be appropriately adjusted according to the applicability and the desired pattern coating cured layer thickness. In general, based on the total weight of the composition, the total content of the polymer is preferably 0.01 to 30% by weight, and preferably 0.3 to 20% by weight.

  The resin composition according to the present invention may contain other additives as necessary. Such additives include surfactants, leveling agents, plasticizers and the like. However, the content of these components is 0.4% or less based on the total weight of the composition.

  The pattern forming method according to the present invention can be carried out according to the method described in Patent Document 1 except that the above-described resin composition is used. The method will be specifically described as follows.

First Fine Pattern Mask Forming Method Hereinafter, the first embodiment of the fine pattern mask forming method according to the present invention will be described in detail with reference to FIGS. 1 (a) to 1 (h). 1A to 1H are cross-sectional views in a direction perpendicular to the length direction of each pattern.

  First, a film 102 to be processed is finally formed on a base material 101 such as a silicon substrate or a glass substrate. At this time, for the purpose of improving the adhesion of the film 102 to be processed on the surface of the base material in advance, improving the flatness of the substrate, and improving the workability in the etching process, etc. (Not shown) can also be provided. In such a case, the film 102 to be processed is formed on the substrate 101 through such a pretreatment intermediate film. Moreover, depending on the kind of base material, the base material to be used can have both a function as a support and a function as a film to be processed. That is, the surface of the substrate can be regarded as a film to be processed, and the substrate surface can be processed using a pattern mask as described later.

  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. The reason for this is that one of the most important features of the present invention is that a mask having a fine pattern is formed directly on 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 processed film or the processing auxiliary intermediate film is processed.

  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 substrate 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% by weight or more. The reason is that if the carbon content is 10% by weight or more, the etching selection ratio with the layer formed by the resin composition described later, in other words, the difference in the etching rate is increased in the etching process, and the processing is performed. This is because it becomes easy. 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 substrate, the intermediate film 103 for processing assistance is directly formed on the surface of the substrate, and by processing it, the substrate surface is processed as a film to be processed. A fine pattern mask is formed.

  Next, the first convex pattern 104 having a convex portion is formed directly on the film 102 to be processed through the intermediate film 103 for processing auxiliary when it exists, and directly when it does not exist (FIG. 1). (A)). Specifically, a resist (for example, a body-type chemically amplified resist) composition or the like is applied, and exposed and developed by a normal method to form a resist pattern 104. However, the formation method of the convex pattern 104 is not limited to this, and can be formed by other methods. For example, a layer made of a material other than the resist composition may be formed, and the layer may be processed by a lithography technique to form the convex pattern 104.

  The radiation sensitive resin composition that can be used to form the resist 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.

  Next, a coating layer is formed on the pattern, and prior to this, a pretreatment for improving the affinity of the resin composition for the pattern surface can be performed. This treatment is a treatment for increasing the hydrophilicity of the pattern surface, and it is considered that this treatment improves the rectangularity of the spacer for the following reason.

  In general, the pattern surface is hydrophilic, whereas the silicon-free organic polymer contained in the composition is hydrophobic. For this reason, when the resin composition is applied to the pattern surface, a repulsive force acts between the silicon-free organic polymer and the pattern surface. This repulsive force moves the non-silicon-containing organic polymer away from the pattern surface in the coating film of the resin composition. As a result, the relatively hydrophilic silicon-containing polymer fills the space near the pattern surface, and above it. A silicon-free organic polymer having a relatively low hydrophilicity will be coated. In such a structure, a layer having a relatively high hydrophilicity, which is easily affected by the variation in hydrophilicity on the resist pattern surface, is covered with a layer having a relatively low hydrophilicity. It is also possible to reduce the influence of sex variation. In the method of the present invention, it is considered that the rectangularity of the formed spacer can be improved by such an effect.

  And the repulsion between a pattern surface and a silicon non-containing organic polymer can be enlarged more, and the effect can be heightened more by performing the pre-processing which makes hydrophilicity of a pattern surface higher. As a result, it is considered that the rectangularity of the spacer can be further improved by the pretreatment.

  Examples of such pretreatment methods include a method of forming a hydrophilic primer layer on the pattern surface and a method of directly hydrophilizing the pattern surface. Examples of the method for forming the primer layer include a method of applying a water-soluble polymer such as polyallylamine, polyacrylic acid, and polyvinyl alcohol, a silane coupling agent, and the like. In addition, as a method for hydrophilizing the pattern surface, the pattern surface is washed with an acid or alkaline aqueous solution and then washed with water, or the pattern surface is subjected to corona discharge treatment, glow discharge treatment, excimer laser light irradiation treatment, low-pressure plasma treatment. The method of doing etc. is mentioned. In these treatments, when the organic solvent is brought into contact with the pattern surface, the pattern surface may be dissolved. Therefore, when the liquid is brought into contact, it is preferable to use an aqueous solution.

  Next, as shown in FIG. 1B, the resin composition is applied so as to cover the first convex pattern 104, thereby forming a coating layer 201.

  The method of applying the resin composition to form the coating layer 201 is, for example, a spin coating method, a spray coating method, a dip coating method, a roller conventionally used when applying a radiation sensitive resin composition. An appropriate method such as a coating method may be used. The applied coating layer is subsequently heated, and the resin composition existing in the vicinity of the first convex pattern is cured.

  The conditions for the heat treatment of the resin composition layer are, for example, 60 to 250 ° C., preferably 80 to 190 ° C., 10 to 300 seconds, preferably about 60 to 210 seconds. The resist pattern and the resin composition layer Preferably, the temperature is such that intermixing occurs. The film thickness of the resin composition layer to be formed can be appropriately adjusted depending on the temperature and time of the heat treatment, the radiation sensitive resin composition used, the water soluble resin 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. According to the present invention, a silicon-containing spacer having good rectangularity can be obtained even when the thickness of the coating layer is increased and the silicon-containing spacer formed is, for example, 15 nm or more. The coating layer can be thickened.

  In this way, by heating the entire substrate, a curing reaction of the coating layer 201 occurs in the vicinity of the convex portion of the first convex pattern. Thereafter, the uncured resin composition is removed by rinsing or plasma treatment of the substrate with a solvent, whereby the first convex pattern is covered with the cured layer 301, and the first convex pattern is refined. Can be obtained (FIG. 1 (c)).

  Here, as a method of leaving only the cured layer 301 formed by heating and removing the unreacted resin composition, a rinsing treatment and a plasma treatment can be mentioned. Either of these may be used as necessary. When the rinsing treatment is employed, the solvent used is selected from those having low solubility in the cured layer and high solubility in the resin composition. More preferably, the solvent used in the resin composition is used for the rinse treatment. In the case of adopting plasma treatment, the conditions are not particularly limited. For example, anisotropic plasma treatment using oxygen or a mixed gas of oxygen and argon can be used. Specific conditions used in this case can be, for example, antenna power 200 W, bias power 200 W, process pressure 0.26 Pa, oxygen flow rate 40 sccm, argon flow rate 5 sccm, and temperature 20 ° C.

  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).

  It should be noted that the embedded bottom surface, that is, the portion other than the above-described convex patterns and spacers, that is, the surface of the processing-assisting intermediate film 103 when the processing assisting intermediate film 103 is present, A cured layer may also be formed on the surface of the film 102. 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. 1) is formed. (D)) is formed.

  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, an etching processing intermediate film 103 (not present) is present. In this case, a portion of the film to be processed) that is not covered with the spacer 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. 1E). 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, since the second convex pattern has a part of the side surface exposed, the width may be narrowed due to the effect of etching. 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-hydroxyethyl acrylate 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. 1 (f)). 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, it is necessary to select a method that does not damage the film to be processed 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. 1G), and the pattern 501 remaining as a mask is further removed as necessary.

  In the above description, a method for forming a fine pattern using a base material on which a film to be processed and an intermediate film for processing are formed on a substrate and using a fine pattern mask directly formed thereon is described. . However, the method according to the present invention is not limited thereto. For example, the processing auxiliary intermediate film 103 is formed on a transparent base material such as a bare glass substrate as a base material, and is processed by the method according to the present invention. A fine pattern mask is formed, and a pattern is formed by performing so-called contact exposure, in which the fine pattern mask is further exposed to a resist film formed on an insulating material film or a conductive material film prepared separately. A fine pattern mask formed according to the above-mentioned method on a substrate is transferred onto a separately prepared insulating material film or conductive material film, and then etched through the pattern mask to form a pattern. You can also let them. Further, the pattern obtained by the present invention can be used as a pattern mask used in the next step.

The second fine pattern mask formation method The first fine pattern mask formation method is to form a pattern using the spacer formed on the side wall of the convex portion of the first convex pattern as a mask. This fine pattern mask forming method forms a pattern by removing the spacer and the lower layer of the spacer. Such a second embodiment of the present invention will be described in detail with reference to FIGS. 2A to 2H.

  First, in the same manner as the first fine pattern forming method, a spacer is formed on the side wall of the convex portion of the first convex pattern (FIGS. 2A to 2D). The steps so far are the same as the first fine pattern forming method.

  Next, a material 104A equivalent to the first convex pattern is embedded in the space between the first convex patterns. (FIG. 2 (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. Therefore, the substance equivalent to the first convex pattern here is not necessarily the same as the substance 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. 2 (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 section of the first fine pattern forming method (FIG. 2F). 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.

  A fine pattern mask for processing the processing target film 102 by processing the processing auxiliary intermediate film 103 using a mask composed of the first convex pattern 104 and a compensation pattern 104A corresponding to the first convex pattern 104 (FIG. 2G). To form. Further, the processed film 102 is processed using the patterned processing auxiliary intermediate film 103 as a mask (FIG. 2H). 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.

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

Example 1A
2.7 g of perhydropolysilazane (manufactured by AZ Electronic Materials) and 2.7 g of poly (styrene-co-α-methylstyrene) (manufactured by Sigma Aldrich) were mixed with dibutyl ether and xylene (mixing weight ratio 67). : 33) The resin composition 1 was obtained by dissolving in 94.6 g.

  ArF resist AX2110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was applied on two silicon substrates, and exposed by a normal method to create two line and space patterns with a pitch of 1: 1.5. .

  Subsequently, the two substrates on which the pattern was formed were pretreated. For pretreatment, SH-114 (trade name, manufactured by AZ Electronic Materials Co., Ltd.) is applied to the surface of the pattern, baked at 90 ° C./90 seconds, rinsed with deionized water for 20 seconds, and baked at 90 ° C./60 seconds. This was done by drying.

  Next, the resin composition 1 was applied to each of the two pretreated substrates, baked at 180 ° C. for 180 seconds, and then cooled. Next, one substrate was rinsed with dibutyl ether for 20 seconds, and then spin-dried at 90 ° C./60 seconds. Another substrate was subjected to anisotropic oxygen plasma treatment for 30 seconds. Thus, a cured layer was formed on the resist surface of each substrate.

  Next, the rectangularity of the obtained cured layer was evaluated. The board | substrate with which the hardened layer was formed was cut | disconnected in the direction perpendicular | vertical to a line, and the cross-sectional photograph was image | photographed by CD-SEM S-9200 (brand name, Hitachi High-Technologies Corporation make). The angle θ formed between the side surface of the cured layer covering the line and the silicon substrate surface was measured.

  Next, using a dry etcher (NE5000N type, ULVAC, Inc.), the upper part of the resist pattern and the lower layer part between the resist patterns were removed to double the pattern. This formed a spacer. The LER and width of the spacer were measured using CD-SEM S-9200 (trade name, manufactured by Hitachi High-Technologies Corporation).

Example 1B
A spacer was formed in the same manner as in Example 1A, except that no pretreatment was performed after forming a pattern with an ArF resist, and its characteristics were evaluated.

Comparative Example 1A
5.4 g of perhydropolysilazane (manufactured by AZ Electronic Materials Co., Ltd.) was dissolved in 94.6 g of a mixed solution of dibutyl ether and xylene to obtain a resin composition R1.

  An ArF resist AX2110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was applied on a silicon substrate, and was exposed by a normal method to create a line and space pattern with a pitch of 1: 1.5.

  Subsequently, the substrate on which the pattern was formed was pretreated. For pretreatment, SH-114 (trade name, manufactured by AZ Electronic Materials Co., Ltd.) is applied to the surface of the pattern, baked at 90 ° C./90 seconds, rinsed with deionized water for 20 seconds, and baked at 90 ° C./60 seconds. This was done by drying.

  Next, the resin composition R1 was applied to each of the two pretreated substrates, baked at 130 ° C./60 seconds, and then cooled. Next, one substrate was rinsed with dibutyl ether for 20 seconds, and then spin-dried at 90 ° C./60 seconds. Another substrate was subjected to anisotropic oxygen plasma treatment for 30 seconds. As a result, a cured layer was formed on the resist surface of each substrate.

  Next, the pattern was doubled in the same manner as in Example 1, and the characteristics of the spacer were evaluated.

Comparative Example 1B
A spacer was formed in the same manner as in Comparative Example 1A except that the pretreatment was not performed after the pattern was formed with the ArF resist and the heating condition after application of the resin composition was changed to 150 ° C./60 seconds. Evaluated.

The characteristic values of the spacers obtained in Examples 1A and 1B and Comparative Examples 1A and 1B were as described in Table 1.

Reference Example 2B
Resin composition 2 was prepared by dissolving 0.5 g of polyphenylsilsesquioxane (manufactured by AZ Electronic Materials) and 4.7 g of polystyrene (manufactured by Sigma Aldrich) in 94.8 g of a mixed solution of dibutyl ether and xylene. Got.

  An ArF resist AX2110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was applied on a silicon substrate, and was exposed by a normal method to create a line and space pattern with a pitch of 1: 1.5. Three substrates having this pattern were prepared.

  Next, the resin composition 2 was applied to each substrate, baked at 60 ° C./60 seconds, 120 ° C./60 seconds, and 180 ° C./60 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, a spacer was formed on the side surface of the pattern.

The substrate after the treatment was observed using CD-SEM S-9200 (trade name, manufactured by Hitachi High-Technologies Corporation), and the dimensions of the lines before and after the treatment with the resin composition were measured. The thickness of the spacer formed on each substrate was calculated by the following formula.
Spacer thickness = (width of line after treatment−width of line before treatment) / 2

  From the spacer thicknesses of the three substrates, the growth rate of the spacer with respect to the heating temperature was calculated. Based on the spacer thickness determined as described above, the spacer thickness was plotted against the heating temperature, and regression analysis was performed to determine the temperature dependence of the spacer formation rate corresponding to the slope of the regression line. .

Example 3B
Perhydropolysilazane (manufactured by AZ Electronic Materials Co., Ltd.) 2.7 g, and polystyrene - and (Sigma Aldrich) 2.7 g, was dissolved a mixture of dibutyl over ether and xylene 94.6 g, resin Product 3 was obtained. Three substrates having ArF resist patterns were prepared in the same manner as in Reference Example 2B. Next, the resin composition 3 was applied to each substrate, baked at 170 ° C./60 seconds, 180 ° C./60 seconds, and 190 ° C./60 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, pattern side spacers were formed.

The same evaluation as in Reference Example 2B was performed on the treated substrate, and the temperature dependency of the spacer formation rate was determined.

Comparative Example 2B
5.2 g of polyphenylsilsesquioxane (manufactured by AZ Electronic Materials Co., Ltd.) was dissolved in 94.8 g of a mixed solution of dibutyl ether and xylene to obtain a resin composition R2.

Three substrates having ArF resist patterns were prepared in the same manner as in Reference Example 2B. Next, the resin composition R2 was applied to each substrate, baked under conditions of 160 ° C./60 seconds, 170 ° C./60 seconds, and 180 ° C./60 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, a spacer was formed on the side surface of the pattern.

The same evaluation as in Reference Example 2B was performed on the treated substrate, and the temperature dependency of the spacer formation rate was determined.

Comparative Example 3B
5.4 g of perhydropolysilazane (manufactured by AZ Electronic Materials Co., Ltd.) was dissolved in 94.6 g of a mixed solution of dibutyl ether and xylene to obtain a resin composition R3.

Three substrates having ArF resist patterns were prepared in the same manner as in Reference Example 2B. Next, the resin composition R3 was applied to each substrate, baked under conditions of 135 ° C./60 seconds, 145 ° C./60 seconds, and 155 ° C./60 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, a spacer was formed on the side surface of the pattern.

The same evaluation as in Reference Example 2B was performed on the treated substrate, and the temperature dependency of the spacer formation rate was determined.

The temperature dependency of the spacer formation rate obtained in Reference Example 2B and Comparative Examples 2B and 3 was as described in Table 2. The evaluation criteria were as follows.
A: Very stable B: Stable C: Unstable D: Very unstable

Example 4A
3.9 g of perhydropolysilazane (manufactured by AZ Electronic Materials) and 1.7 g of poly (styrene-co-α-methylstyrene) (manufactured by Sigma Aldrich) are dissolved in 94.4 g of a mixed solution of dibutyl ether and xylene. Thus, a resin composition 4 was obtained.

  An ArF resist AX2110P (trade name, manufactured by AZ Electronic Materials Co., Ltd.) was applied on a silicon substrate, and was exposed by a normal method to create a line and space pattern with a pitch of 1: 1.5. Three substrates having this pattern were prepared.

  Subsequently, each substrate on which the pattern was formed was pretreated. For pretreatment, SH-114 (trade name, manufactured by AZ Electronic Materials Co., Ltd.) is applied to the surface of the pattern, baked at 90 ° C./90 seconds, rinsed with deionized water for 20 seconds, and baked at 90 ° C./60 seconds. This was done by drying.

  Next, the resin composition 4 was applied to each substrate, baked under conditions of 180 ° C./180 seconds, 180 ° C./240 seconds, and 180 ° C./300 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, a spacer was formed on the side surface of the pattern.

The substrate after the treatment was observed using CD-SEM S-9200 (trade name, manufactured by Hitachi High-Technologies Corporation), and the dimensions of the lines before and after the treatment with the resin composition were measured. The thickness of the spacer formed on each substrate was calculated by the following formula.
Spacer thickness = (width of line after treatment−width of line before treatment) / 2

  From the spacer thicknesses of the three substrates, the growth rate of the spacer with respect to the heating time was calculated. Based on the spacer thickness obtained as described above, plot the spacer thickness against the heating time and perform regression analysis to determine the heating time dependence of the spacer formation rate corresponding to the slope of the regression line. It was.

Comparative Example 4A
5.4 g of perhydropolysilazane (manufactured by AZ Electronic Materials) was dissolved in 94.6 g of a mixed liquid of dibutyl ether and xylene to obtain a resin composition R4.

  In the same manner as in Example 4A, three pretreated substrates having an ArF resist pattern were prepared. Next, resin composition R4 was applied to each substrate, baked at 90 ° C./120 seconds, 90 ° C./180 seconds, and 90 ° C./240 seconds, cooled, and rinsed with dibutyl ether for 20 seconds. Spin drying at 90 ° C./60 seconds. By this treatment, a spacer was formed on the side surface of the pattern.

  Evaluation similar to Example 4A was performed with respect to the processed substrate, and the heating time dependency of the spacer formation rate was determined.

DESCRIPTION OF SYMBOLS 101 Base material 102 Processed film 103 Processing assisting intermediate film 104 First convex pattern 104A Embedding material 201 Covering layer 301 Hardened layer 401 Spacer 501 Pattern 501 derived from processing assisting intermediate film
601 fine pattern

Claims (10)

Perhydropolysilazane ,
The following general formula (II):

(Wherein R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 5 to 7 carbon atoms,
R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or an aryl group having 6 to 10 carbon atoms,
p is a number indicating the degree of polymerization. )
A silicon-free organic polymer having at least one repeating unit represented by:
Solvent,
A composition for forming a fine pattern, comprising: The composition for forming a fine pattern according to claim 1, wherein the weight average molecular weight of the perhydropolysilazane is 500 to 100,000, and the weight average molecular weight of the silicon-free organic polymer is 500 to 400,000. The composition for fine pattern formation of Claim 1 or 2 whose compounding ratio of the said perhydropolysilazane and the said silicon-free organic polymer is 10: 90-90: 10 by weight ratio. A step of preparing a base material on which a film to be processed is laminated,
Forming a first convex pattern having a convex portion on the film to be processed;
The application | coating process which apply | coats the resin composition of any one of Claims 1-3 on said 1st 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 or plasma treatment of 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 mask, comprising the step of forming a fine second convex pattern mask made of the different kind of material by removing the portion. A step of preparing a base material in which a film to be processed and an intermediate film for processing are sequentially laminated on the surface;
Forming a first convex pattern having a convex portion on the processing-assisting intermediate film;
The application | coating process which apply | coats the resin composition of any one of Claims 1-3 on said 1st 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 or plasma treatment of 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;
Removing the first convex portion to form a fine second convex pattern mask made of the different kind of substance, and forming the processing-assisting intermediate film via the second convex pattern mask. A method for forming a fine pattern mask, comprising a step of forming a fine pattern mask for processing a film to be processed by etching. A step of preparing a base material on which a film to be processed is laminated,
Forming a first convex pattern having a convex portion on the film to be processed;
The application | coating process which apply | coats the resin composition of any one of Claims 1-3 on said 1st 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 or plasma treatment of 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;
By embedding a material equivalent to the first convex pattern in the space portion, forming a compensation pattern for the first convex pattern, and removing the layer made of the different material, the first convex pattern A method for forming a fine pattern mask, comprising a step of forming a fine pattern mask comprising a pattern and a compensation pattern for the first convex pattern. A step of preparing a base material in which a film to be processed and an intermediate film for processing are sequentially laminated on the surface;
Forming a first convex pattern having a convex portion on the processing-assisting intermediate film;
The application | coating process which apply | coats the resin composition of any one of Claims 1-3 on said 1st 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 first convex pattern;
Removing the uncured resin composition by rinsing or plasma treatment of 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;
Embedding a material equivalent to the first convex pattern into the space between the convex parts, and forming a compensation pattern for the first convex pattern;
The step of forming a fine pattern consisting of the first convex pattern and a compensation pattern for the first convex pattern by removing the layer made of the different kind of substance, and the first convex pattern and the A fine pattern mask comprising: a step of etching the processing auxiliary intermediate film through a filling pattern for the first convex pattern to form a fine pattern mask for processing the film to be processed. Forming method. The method for forming a fine pattern mask according to any one of claims 4 to 7 , wherein the first convex pattern is formed from a photoresist. A fine pattern mask formed by the method according to claim 4 . A method for forming a fine pattern, comprising the step of etching the film to be processed using the fine pattern mask according to claim 9 as an etching mask.

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