JP6958040B2 - Laminate - Google Patents

Description

The present invention relates to a laminate.

Conventionally, in fields such as semiconductor manufacturing, ionizing radiation such as electron beams and short-wavelength light such as ultraviolet rays (hereinafter, ionizing radiation and short-wavelength light may be collectively referred to as "ionizing radiation and the like"). A polymer in which the main chain is cleaved by irradiation and the solubility in a developing solution is increased is used as a main chain cleaving type positive resist.

Then, for example, in Patent Document 1, methyl α-methylstyrene / α-chloroacrylate containing an α-methylstyrene unit and a methyl chloroacrylate unit as a highly sensitive main chain cleavage type positive resist. A positive resist made of a copolymer is disclosed.

Further, in a semiconductor element such as an LSI chip, for example, the photomask is irradiated with ultraviolet light, and the process of reducing and transferring the circuit pattern on the photomask onto a silicon wafer is repeated to form a complicated three-dimensional structure, one by one. Manufactured by cutting out. Here, as shown in FIG. 1, for example, a laminate 50 in which a resist film 40 is formed on a photomask blank 30 composed of a substrate 10 and a light-shielding layer 20 formed on the substrate 10 is prepared (FIG. 1). 1 (a)), an electron beam 60 is drawn on the laminated body 50, developed (FIG. 1 (b)), the light-shielding layer 20 is etched (FIG. 1 (c)), and the resist film remaining on the light-shielding layer 20 is formed. A photomask 100 is manufactured by removing 40 (FIG. 1 (d)), and a master template is manufactured by further etching the substrate 10 (FIG. 1 (e)) and removing the light-shielding layer 20. (Fig. 1 (f)).

Special Fair 8-3636 Gazette

Here, in the manufacturing process of the photomask 100, the adhesion between the resist film 40 and the light-shielding layer 20 may decrease. Therefore, in the manufacturing process of a mask (transfer mask) such as a photomask 100, it is required to suppress a decrease in adhesion between the resist film 40 and the light-shielding layer 20.

However, in the resist film formed by using the positive resist composed of the α-methylstyrene / α-methylchloroacrylate copolymer described in Patent Document 1, the adhesion between the resist film and the light-shielding layer is sufficiently lowered. It could not be suppressed.

Therefore, an object of the present invention is to provide a resist laminate capable of improving the adhesion between the resist film and the light-shielding layer.

The present inventor has made diligent studies to achieve the above object. Then, the present inventor sufficiently suppresses a decrease in the adhesion between the resist film and the light-shielding layer in a laminate in which a resist film containing a predetermined polymer having a predetermined monomer unit is formed on the light-shielding layer. We found that it was possible and completed the present invention.

（式（Ｉ）中、Ｒ^１は、塩素原子、フッ素原子またはフッ素原子で置換されたアルキル基であり、Ｒ^２は、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、Ｒ^３およびＲ^４は、水素原子、フッ素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、互いに同一でも異なっていてもよい。）
で表される単量体単位（Ａ）と、
下記一般式（ＩＩ）：

（式（ＩＩ）中、Ｒ^５、Ｒ^６、Ｒ^８およびＲ^９は、水素原子、フッ素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、互いに同一でも異なっていてもよく、Ｒ^７は、水素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、ｐおよびｑは、０以上５以下の整数であり、ｐ＋ｑ＝５である。）
で表される単量体単位（Ｂ）とを有し、
前記単量体単位（Ａ）および前記単量体単位（Ｂ）の少なくとも一方がフッ素原子を一つ以上有する、ことを特徴とする。
所定の単量体単位を有する所定の重合体を含むレジスト膜が遮光層上に形成された積層体は、レジスト膜と遮光層との密着性の低下を十分に抑制可能である。
なお、本発明において、式（ＩＩ）中のｐが２以上の場合には、複数あるＲ^６は互いに同一でも異なっていてもよく、また、式（ＩＩ）中のｑが２以上の場合には、複数あるＲ^７は互いに同一でも異なっていてもよい。 That is, the present invention aims to advantageously solve the above problems, and the laminate of the present invention is formed on a substrate, a light-shielding layer formed on the substrate, and the light-shielding layer. It is a laminated body provided with a resist film.
The resist film contains a polymer and contains
The polymer is
The following general formula (I):

In formula (I), R ¹ is an alkyl group substituted with a chlorine atom, a fluorine atom or a fluorine atom, R ² is an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom, and R ³ and R ⁴ are hydrogen atoms, fluorine atoms, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, and may be the same or different from each other.)
The monomer unit (A) represented by
The following general formula (II):

In formula (II), R ⁵ , R ⁶ , R ⁸ and R ⁹ are hydrogen atoms, fluorine atoms, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, which may be the same or different from each other. Often, R ⁷ is an alkyl group substituted with a hydrogen atom, an unsubstituted alkyl group or a fluorine atom, and p and q are integers of 0 or more and 5 or less, and p + q = 5).
It has a monomer unit (B) represented by
It is characterized in that at least one of the monomer unit (A) and the monomer unit (B) has one or more fluorine atoms.
A laminate in which a resist film containing a predetermined polymer having a predetermined monomer unit is formed on a light-shielding layer can sufficiently suppress a decrease in adhesion between the resist film and the light-shielding layer.
In the present invention, when p in the formula (II) is 2 or more, the plurality of R ^6s may be the same or different from each other, and when q in the formula (II) is 2 or more. The plurality of R ^7s may be the same or different from each other.

Further, in the laminate of the present invention, ^{it is preferable that R 1} is a chlorine atom. ^{When R 1} of the monomer unit (A) is a chlorine atom, the breakability of the main chain of the polymer when irradiated with ionizing radiation or the like can be improved. Therefore, it can be satisfactorily used in the manufacture of masks such as photomasks. Further, it is easy to prepare a polymer in which ^{R 1 of} the monomer unit (A) is a chlorine atom.

Further, in the laminate of the present invention, it is preferable that R ² is an alkyl group substituted with a fluorine atom, and R ^{3 and R 4} are hydrogen atoms or unsubstituted alkyl groups. ^{If R 2} of the monomer unit (A) is an alkyl group substituted with a fluorine atom and R ³ and R ⁴ are hydrogen atoms or unsubstituted alkyl groups, the polymer when irradiated with ionizing radiation or the like. It is possible to improve the breakability of the main chain of. Therefore, it can be satisfactorily used in the manufacture of masks such as photomasks. R ³ and R ⁴ may be the same or different from each other.

Furthermore, in the laminate of the present invention, the p is an integer of 1 or more and 5 or less, R ⁵ and R ^{7 to} R ⁹ are hydrogen atoms or unsubstituted alkyl groups, and the monomer unit (A). Preferably has one or more hydrogen atoms. The p of the monomer unit (B) is an integer of 1 or more and 5 or less, R ⁵ and R ^{7 to} R ⁹ are hydrogen atoms or unsubstituted alkyl groups, and the monomer unit (A) is a fluorine atom. If one or more of them are provided, the polymer can be easily prepared, and the breakability of the main chain of the polymer when irradiated with ionizing radiation or the like can be improved. Therefore, it can be satisfactorily used in the manufacture of masks such as photomasks.

Furthermore, in the laminate of the present invention, the number of fluorines in the monomer unit (B) is preferably 0 or 1. When the number of fluorine in the monomer unit (B) is 0 or 1, it can be satisfactorily used for producing a mask such as a photomask.

Furthermore, the laminate of the present invention, it is preferable that the R ² is a pentafluorobutane alkyl group. ^{When R 2} of the monomer unit (A) is a pentafluoroalkyl group, a laminate capable of producing a mask having a clear pattern while sufficiently improving the sensitivity of the resist film can be obtained.

Furthermore, the laminate of the present invention, it is preferable that the ^{R 2} is a 2,2,3,3,3-pentafluoro-propyl. ^{When R 2} of the monomer unit (A) is a 2,2,3,3,3-pentafluoropropyl group, it is possible to produce a mask having a clear pattern while sufficiently improving the sensitivity of the resist film. A laminate is obtained.

Furthermore, in the laminate of the present invention, it is preferable that the monomer unit (B) is a structural unit derived from α-methylstyrene or a structural unit derived from 4-fluoro-α-methylstyrene. If the monomer unit (B) is a structural unit derived from α-methylstyrene, the ease of preparation of the polymer can be improved, and the main chain of the polymer when irradiated with ionizing radiation or the like can be improved. The cutability can be improved. Therefore, it can be satisfactorily used in the manufacture of masks such as photomasks. If the monomer unit (B) is a structural unit derived from 4-fluoro-α-methylstyrene, a laminate capable of producing a mask having a pattern in which the occurrence of collapse is suppressed can be obtained.

Furthermore, in the laminate of the present invention, the weight average molecular weight of the polymer is preferably 59000 or less. A polymer having a weight average molecular weight of 59000 or less can sufficiently suppress the occurrence of resist pattern collapse when used as a positive resist, and can appropriately increase the sensitivity, so that it is a main chain cut type polymer. It can be satisfactorily used as a positive resist. Therefore, a laminate having excellent sensitivity of the resist film and capable of producing a mask having a good pattern can be obtained. In the present invention, the "weight average molecular weight (Mw)" can be measured by using gel permeation chromatography.

Furthermore, in the laminate of the present invention, the weight average molecular weight of the polymer is preferably 43,800 or more. When the weight average molecular weight of the polymer is 43,800 or more, it is possible to suppress an excessive decrease in the γ value when used as a main chain breaking type positive resist composition. Therefore, a laminate capable of producing a mask having a good pattern can be obtained.

Furthermore, the laminate of the present invention preferably has a polymer molecular weight distribution (Mw / Mn) of 1.50 or less. As long as the molecular weight distribution of the polymer is within such a range, a laminate capable of producing a mask having a clear pattern while improving the ease of producing the polymer can be obtained.
In the present invention, the "molecular weight distribution (Mw / Mn)" refers to the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). Then, in the present invention, the "number average molecular weight (Mn)" can be measured by using gel permeation chromatography in the same manner as the above-mentioned "weight average molecular weight (Mw)".

According to the laminate of the present invention, the adhesion between the resist film and the light-shielding layer can be improved.

It is a figure which shows an example of the manufacturing method of the photomask which manufactures a photomask, (a) shows a laminate formation process, (b) shows an electron beam drawing process, (c) shows a light-shielding layer etching process. , (D) show a resist film removing step, (e) shows a substrate etching step, and (f) shows a light-shielding layer removing step.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the laminate of the present invention is used, for example, in the manufacturing process of a printed circuit board such as a build-up substrate, when manufacturing a transfer mask such as a photomask used for manufacturing a semiconductor element or the like.
The polymer contained in the resist film of the laminate of the present invention has a reduced molecular weight by cutting the main chain by ionizing radiation such as an electron beam or EUV (Extreme ultimate) laser or irradiation with short wavelength light such as ultraviolet rays. It can be satisfactorily used as a main chain cutting type positive resist.

(Laminated body)
The laminate of the present invention includes a substrate, a light-shielding layer formed on the substrate, and a resist film formed on the light-shielding layer and containing a predetermined polymer.

<Board>
As the substrate, a transparent substrate is usually used. Examples of the material of the substrate include transparent materials such as quartz and glass. These may be used alone or in combination of two or more. Among these, quartz is preferable from the viewpoint of transparency and weather resistance.
The substrate preferably has transparency of 90% to 95% of light having a wavelength of 200 nm or more and 300 nm or less.
The thickness of the substrate is preferably 0.5 mm or more, more preferably 1.0 mm or more, preferably 20 mm or less, and more preferably 15 mm or less.

<Shading layer>
Any light-shielding layer can be used as the light-shielding layer. Above all, as the light-shielding layer, it is preferable to use a light-shielding layer having a single-layer structure or a multi-layer structure including a metal layer. Examples of the material of the layer other than the metal layer that can form the light-shielding layer include polypropylene, cyclic polyolefin, and polyvinyl chloride.
Examples of the material of the metal layer include chromium, silicon, iron oxide, molybdenum Silicide and the like. These may be used alone or in combination of two or more. Among these, chromium is preferable from the viewpoint of light-shielding property.
The thickness of the light-shielding layer is preferably 5 nm or more, more preferably 10 nm or more, preferably 200 nm or less, and more preferably 100 nm or less.

<Resist film>
The resist film contains a predetermined polymer. Thereby, the adhesion between the resist film and the light-shielding layer can be improved.
The thickness of the resist film is preferably 20 nm or more, more preferably 30 nm or more, preferably 200 nm or less, and more preferably 100 nm or less.

<< Polymer >>
Hereinafter, the properties of the polymer in the resist film of the laminate of the present invention, that is, the "weight average molecular weight (Mw)", "number average molecular weight (Mn)" and "molecular weight distribution (Mw / Mn)" of the polymer will be described. do.
In the present invention, the "weight average molecular weight (Mw)" and the "number average molecular weight (Mn)" can be measured by using gel permeation chromatography. In the present invention, the "molecular weight distribution (Mw / Mn)" refers to the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

[Weight average molecular weight]
The weight average molecular weight (Mw) of the polymer in the resist film of the laminate of the present invention can be, for example, 59000 or less, and 43,800 or more. Further, the weight average molecular weight (Mw) of the polymer in the resist film of the laminate of the present invention is preferably 52000 or less, and preferably 46500 or more. When the weight average molecular weight (Mw) of the polymer in the resist film of the laminate of the present invention is not more than (less than) the above upper limit value, the sensitivity of the resist film can be improved. Further, when the weight average molecular weight (Mw) of the polymer in the resist film of the laminate of the present invention is at least the above lower limit value, dissolution in the developing solution can be prevented.

[Number average molecular weight]
Further, the number average molecular weight (Mn) of the polymer in the resist film of the laminate of the present invention can be, for example, 29600 or more and 43500 or less. Further, the number average molecular weight (Mn) of the polymer of the polymer in the resist film of the laminate of the present invention is preferably 41600 or less, more preferably 36500 or more. When the number average molecular weight (Mn) of the polymer of the polymer in the resist film of the laminate of the present invention is not more than (less than) the above upper limit value, the sensitivity of the resist film can be improved. Further, when the number average molecular weight (Mn) of the polymer in the resist film of the laminate of the present invention is at least the above lower limit value, dissolution in the developing solution can be prevented.

[Molecular weight distribution]
The molecular weight distribution (Mw / Mn) of the polymer of the polymer in the resist film of the laminate of the present invention can be, for example, 1.50 or less. Further, the molecular weight distribution (Mw / Mn) of the polymer of the polymer in the resist film of the laminate of the present invention is preferably 1.28 or more, more preferably 1.30 or more, and 1.45. It is preferably 1.40 or less, and more preferably 1.40 or less. When the molecular weight distribution (Mw / Mn) of the polymer in the resist film of the laminate of the present invention is at least the above lower limit value, the prebaking time can be shortened. When the molecular weight distribution (Mw / Mn) of the polymer is not more than the above upper limit value, a clear pattern can be obtained at the time of patterning.

The composition, molecular weight distribution, weight average molecular weight, and number average molecular weight of the polymer can be adjusted by changing the polymerization conditions, purification conditions, and film formation conditions (heating temperature / heating time). Specifically, for example, the composition of the polymer can be adjusted by changing the content ratio of each monomer in the monomer composition used for the polymerization. Further, the weight average molecular weight and the number average molecular weight can be reduced by increasing the polymerization temperature. Further, the weight average molecular weight and the number average molecular weight can be reduced by shortening the polymerization time.

<< Resist film forming method >>
In the resist film forming method, a positive resist composition containing a polymer for forming a resist film is applied onto the above-mentioned light-shielding layer, and the applied positive resist composition is dried to form a resist film. The coating method and the drying method are not particularly limited, and known coating methods and drying methods can be used. The molecular weight of the resist film-forming polymer may change during the drying of the positive resist composition.

<<< Positive resist composition >>>
The positive resist composition contains a polymer for forming a resist film and a solvent, and optionally further contains a known additive that can be incorporated into the resist composition. Since the positive resist composition contains a predetermined polymer for forming a resist film as a positive resist, it is possible to sufficiently suppress the occurrence of the resist pattern from collapsing when used for forming the resist pattern. can.

〔solvent〕
As the solvent, a known solvent can be used as long as it can dissolve the polymer for forming a resist film. Among them, from the viewpoint of obtaining a positive resist composition having an appropriate viscosity and improving the coatability of the positive resist composition, as the solvent, anisole, propylene glycol methyl ether acetate (PGMEA), n-hexyl acetate, etc. It is preferable to use amyl acetate, a mixture thereof, or the like.

（式（Ｉ）中、Ｒ^１は、塩素原子、フッ素原子またはフッ素原子で置換されたアルキル基であり、Ｒ^２は、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、Ｒ^３およびＲ^４は、水素原子、フッ素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、Ｒ^３およびＲ^４は互いに同一でも異なっていてもよい。）で表される単量体単位（Ａ）と、
下記の一般式（ＩＩ）：

（式（ＩＩ）中、Ｒ^５、Ｒ^６、Ｒ^８およびＲ^９は、水素原子、フッ素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、互いに同一でも異なっていてもよく、Ｒ^７は、水素原子、非置換のアルキル基またはフッ素原子で置換されたアルキル基であり、ｐおよびｑは、０以上５以下の整数であり、ｐ＋ｑ＝５である。）で表される単量体単位（Ｂ）とを有する。
また、前記レジスト膜形成用重合体は、単量体単位（Ａ）および単量体単位（Ｂ）の少なくとも一方がフッ素原子を一つ以上有する。即ち、前記レジスト膜形成用重合体は、単量体単位（Ａ）がフッ素原子を一つ以上有し、単量体単位（Ｂ）がフッ素原子を有していなくてもよいし、単量体単位（Ｂ）がフッ素原子を一つ以上有し、単量体単位（Ａ）がフッ素原子を有していなくてもよいし、単量体単位（Ａ）および単量体単位（Ｂ）のそれぞれがフッ素原子を一つ以上有していてもよい。
なお、前記レジスト膜形成用重合体は、単量体単位（Ａ）および単量体単位（Ｂ）以外の任意の単量体単位を含んでいてもよいが、レジスト膜形成用重合体を構成する全単量体単位中で単量体単位（Ａ）および単量体単位（Ｂ）が占める割合は、合計で９０ｍｏｌ％以上であることが好ましく、実質的に１００ｍｏｌ％であることがより好ましく、１００ｍｏｌ％（即ち、レジスト膜形成用重合体は単量体単位（Ａ）および単量体単位（Ｂ）のみを含む）であることがさらに好ましい。 [Polymer for forming a resist film]
The polymer for forming a resist film is
The following general formula (I):

In formula (I), R ¹ is an alkyl group substituted with a chlorine atom, a fluorine atom or a fluorine atom, R ² is an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom, and R ³ and R ⁴ are hydrogen atoms, fluorine atoms, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, and R ³ and R ⁴ may be the same or different from each other). Quantitative unit (A) and
The following general formula (II):

In formula (II), R ⁵ , R ⁶ , R ⁸ and R ⁹ are hydrogen atoms, fluorine atoms, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, which may be the same or different from each other. Often, R ⁷ is an alkyl group substituted with a hydrogen atom, an unsubstituted alkyl group or a fluorine atom, and p and q are integers of 0 or more and 5 or less, and p + q = 5). It has a monomer unit (B).
Further, in the resist film forming polymer, at least one of the monomer unit (A) and the monomer unit (B) has one or more fluorine atoms. That is, in the polymer for forming a resist film, the monomer unit (A) may have one or more fluorine atoms, and the monomer unit (B) may not have a fluorine atom, or a single amount. The body unit (B) may have one or more fluorine atoms, and the monomer unit (A) may not have a fluorine atom, or the monomer unit (A) and the monomer unit (B). Each of these may have one or more fluorine atoms.
The polymer for forming a resist film may contain any monomer unit other than the monomer unit (A) and the monomer unit (B), but constitutes a polymer for forming a resist film. The ratio of the monomer unit (A) and the monomer unit (B) to all the monomer units is preferably 90 mol% or more in total, and more preferably 100 mol% substantially. , 100 mol% (that is, the polymer for forming a resist film contains only the monomer unit (A) and the monomer unit (B)).

Since the resist film-forming polymer contains a predetermined monomer unit (A) and a monomer unit (B), ionizing radiation and the like (for example, electron beam, KrF laser, ArF laser, EUV) When (Excimer Ultraviolet) laser or the like is irradiated, the main chain of the polymer for forming a resist film is cleaved to reduce the molecular weight. Further, since at least one of the monomer unit (A) and the monomer unit (B) has one or more fluorine atoms in the resist film-forming polymer, it is prebaked when used as a resist. Sometimes the heat resistance is high, decomposition is suppressed, the adhesion to the light-shielding layer can be improved, and the occurrence of the resist pattern collapse can be sufficiently suppressed.
Although it is not clear why the occurrence of the resist pattern collapse can be suppressed by containing a fluorine atom in at least one of the monomer unit (A) and the monomer unit (B), the resist film It is presumed that this is because the liquid repellency of the forming polymer is improved, and it is possible to suppress the occurrence of tension between the patterns when the developing solution and the rinsing solution are removed in the process of forming the resist pattern. ..

（式（ＩＩＩ）中、Ｒ^１〜Ｒ^４は、式（Ｉ）と同様である。）で表される単量体（ａ）に由来する構造単位である。 [[Monomer unit (A)]]
Here, the monomer unit (A) is represented by the following general formula (III):

(In the formula (III), R ^{1 to} R ⁴ are the same as those in the formula (I)), which is a structural unit derived from the monomer (a) represented by the formula (I).

The ratio of the monomer unit (A) to all the monomer units constituting the polymer for forming a resist film is not particularly limited, and can be, for example, 30 mol% or more and 70 mol% or less.

^{Here, the alkyl group substituted with a fluorine atom that can constitute R 1 to} R ⁴ in the formulas (I) and (III) is not particularly limited, and is one of the hydrogen atoms in the alkyl group. Examples thereof include a group having a structure in which a part or the whole is substituted with a hydrogen atom.
^{Further, the unsubstituted alkyl group capable of constituting R 2 to} R ⁴ in the formulas (I) and (III) is not particularly limited, and an unsubstituted alkyl group having 1 or more and 10 or less carbon atoms is used. Can be mentioned. Of these, ^{as the unsubstituted alkyl group capable of forming R 2 to} R ⁴ , a methyl group or an ethyl group is preferable.

From the viewpoint of improving the breakability of the main chain of the resist film-forming polymer when irradiated with ionizing radiation or the like, R ¹ in the formulas (I) and (III) is a chlorine atom, a fluorine atom or It is preferably an alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, more preferably a chlorine atom, a fluorine atom or a perfluoromethyl group, further preferably a chlorine atom or a fluorine atom. It is particularly preferably a chlorine atom. ^{The monomer (a) in which R 1} in the formula (III) is a chlorine atom has excellent polymerizable properties, and the monomer unit (A) in which ^{R 1 in the formula (I) is a chlorine atom.} The polymer for forming a resist film having the above is also excellent in that it is easy to prepare.

Further, from the viewpoint of improving the breakability of the main chain of the polymer for forming a resist film when irradiated with ionizing radiation or the like, R ² in the formulas (I) and (III) was replaced with a fluorine atom. It is preferably an alkyl group, and more preferably an alkyl group having 1 or more and 10 or less carbon atoms substituted with a fluorine atom.
Examples of the alkyl group having 1 or more and 10 or less carbon atoms substituted with a fluorine atom include 2,2,2-trifluoroethyl group and 2,2,3,3,3-pentafluoropropyl group (number of fluorine atoms). Is 5, the number of carbon atoms is 3, pentafluoroalkyl group such as the following structural formula X), 2- (perfluorobutyl) ethyl group, 2- (perfluorohexyl) ethyl group, 1H, 1H, 3H-tetrafluoropropyl group. , 1H, 1H, 5H-octafluoropentyl group, 1H, 1H, 7H-dodecafluoroheptyl group, 1H-1- (trifluoromethyl) trifluoroethyl group, 1H, 1H, 3H-hexafluorobutyl group, 1, Examples thereof include 2,2,2-tetrafluoro-1- (trifluoromethyl) ethyl group.
Among these, a pentafluoroalkyl group is preferable, and a 2,2,3,3,3-pentafluoropropyl group (the number of fluorine atoms is 5, the number of carbon atoms is 3, and the following structural formula X) is particularly preferable.

Further, from the viewpoint of improving the breakability of the main chain of the resist film-forming polymer when irradiated with ionizing radiation or the like, R ³ and R ⁴ in the formulas (I) and (III) are hydrogen, respectively. It is preferably an atomic or unsubstituted alkyl group, more preferably a hydrogen atom or an unsubstituted alkyl group having 1 or more and 5 or less carbon atoms, and further preferably a hydrogen atom.

The monomer (a) represented by the above-mentioned formula (I), which can form the monomer unit (A) represented by the above-mentioned formula (I), is not particularly limited. For example, α-chloroacrylic acid 2,2,2-trifluoroethyl, α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl, α-chloroacrylic acid 2- (perfluorobutyl) ethyl, 2- (Perfluorohexyl) ethyl α-chloroacrylic acid, α-chloroacrylic acid 1H, 1H, 3H-tetrafluoropropyl, α-chloroacrylic acid 1H, 1H, 5H-octafluoropentyl, α-chloroacrylic acid 1H , 1H, 7H-dodecafluoroheptyl, α-chloroacrylic acid 1H-1- (trifluoromethyl) trifluoroethyl, α-chloroacrylic acid 1H, 1H, 3H-hexafluorobutyl, α-chloroacrylic acid 1,2 Α-chloroacrylic acid fluoroalkyl ester such as 2,2-tetrafluoro-1- (trifluoromethyl) ethyl; α-fluoroacrylic acid alkyl ester such as α-fluoroacrylic acid methyl, α-fluoroacrylic acid ethyl; α-Fluoroalkylacrylic acid alkyl esters such as α-trifluoromethylacrylic acid methyl, α-trifluoromethylacrylic acid ethyl; α-fluoroacrylic acid 2,2,2-trifluoroethyl, α-fluoroacrylic acid 2, 2,3,3,3-pentafluoropropyl, 2- (perfluorobutyl) ethyl α-fluoroacrylic acid, 2- (perfluorohexyl) ethyl α-fluoroacrylic acid, α-fluoroacrylic acid 1H, 1H, 3H -Tetrafluoropropyl, α-fluoroacrylic acid 1H, 1H, 5H-octafluoropentyl, α-fluoroacrylic acid 1H, 1H, 7H-dodecafluoroheptyl, α-fluoroacrylic acid 1H-1- (trifluoromethyl) tri Fluoroα-fluoroacrylic acid such as fluoroethyl, α-fluoroacrylic acid 1H, 1H, 3H-hexafluorobutyl, α-fluoroacrylic acid 1,2,2,2-tetrafluoro-1- (trifluoromethyl) ethyl Alkyl ester;

From the viewpoint of further improving the breakability of the main chain of the resist film-forming polymer when irradiated with ionizing radiation or the like, the monomer unit (A) is derived from α-chloroacrylic acid fluoroalkyl ester. It is preferably a structural unit, and particularly preferably α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl. ^{That is, in R 1 to} R ⁴ in the formulas (I) and (III), R ¹ is a chlorine atom, R ² is an alkyl group substituted with a fluorine atom, and R ³ and R ⁴ are hydrogen atoms. Is particularly preferable.

（式（ＩＶ）中、Ｒ^５〜Ｒ^９、並びに、ｐおよびｑは、式（ＩＩ）と同様である。）で表される単量体（ｂ）に由来する構造単位である。
そして、レジスト膜形成用重合体を構成する全単量体単位中の単量体単位（Ｂ）の割合は、特に限定されることなく、例えば３０ｍｏｌ％以上７０ｍｏｌ％以下とすることができる。 [[Monomer unit (B)]]
Further, the monomer unit (B) is represented by the following general formula (IV):

(In formula (IV), R ^{5 to} R ⁹ , and p and q are the same as in formula (II)), which is a structural unit derived from the monomer (b).
The ratio of the monomer unit (B) to all the monomer units constituting the polymer for forming a resist film is not particularly limited, and can be, for example, 30 mol% or more and 70 mol% or less.

^{Here, the alkyl group substituted with a fluorine atom which can constitute R 5 to} R ⁹ in the formula (II) and the formula (IV) is not particularly limited, and is one of the hydrogen atoms in the alkyl group. Examples thereof include a group having a structure in which a part or the whole is substituted with a hydrogen atom.
^{Further, the unsubstituted alkyl group which can constitute R 5 to} R ⁹ in the formula (II) and the formula (IV) is not particularly limited, and an unsubstituted alkyl group having 1 or more and 5 or less carbon atoms is used. Can be mentioned. Of these, ^{as the unsubstituted alkyl group that can constitute R 5 to} R ⁹ , a methyl group or an ethyl group is preferable.

From the viewpoints of easiness of preparing the polymer for forming the resist film and improving the breakability of the main chain of the polymer for forming the resist film when irradiated with ionizing radiation or the like, the formulas (II) and (IV) are used. R ⁵ in the medium is preferably a hydrogen atom or an unsubstituted alkyl group, more preferably an unsubstituted alkyl group having 1 or more carbon atoms and 5 or less carbon atoms, and further preferably a methyl group.

R ⁷ a plurality present in the formula (II) and formula (IV) are all hydrogen atoms or unsubstituted may be an alkyl group, a hydrogen atom or unsubstituted, an alkyl group having 1 to 5 carbon atoms It may be a hydrogen atom or a hydrogen atom. This makes it possible to improve the ease of preparation of the resist film-forming polymer and the breakability of the main chain of the resist film-forming polymer when irradiated with ionizing radiation or the like.
A p 5 in the formula (II) and formula (IV), q is 0, there are five all R ⁶ may be hydrogen atom or an unsubstituted alkyl group, there are five R ⁶ all may be hydrogen atoms or unsubstituted C 1 to 5 alkyl groups, there are five all R ⁶ may be hydrogen atom. This makes it possible to improve the ease of preparation of the polymer for forming a resist film and the breakability of the main chain when irradiated with ionizing radiation or the like.

On the other hand, the resist film forming polymer from further suppressing the occurrence of collapse of the resist pattern when used for forming a resist pattern, R ⁶ is more present in the formula (II) and formula (IV) and / Alternatively, R ⁷ preferably contains an alkyl group substituted with a fluorine atom or a fluorine atom, more preferably contains an alkyl group having 1 or more and 5 or less carbon atoms substituted with a fluorine atom or a fluorine atom, and R ⁶ and / Or it is particularly preferable that the number of fluorine atoms in ^{R 7 is 1.}

Further, from the viewpoint of easiness of preparing the polymer for forming a resist film and improving the breakability of the main chain of the polymer for forming a resist film when irradiated with ionizing radiation or the like, the formulas (II) and (IV) R ⁸ and R ⁹ in the group are preferably hydrogen atoms or unsubstituted alkyl groups, respectively, more preferably hydrogen atoms or unsubstituted alkyl groups having 1 or more and 5 or less carbon atoms, and are hydrogen atoms. It is more preferable to have.

The monomer (b) represented by the above-mentioned formula (IV), which can form the monomer unit (B) represented by the above-mentioned formula (II), is not particularly limited. For example, α-methylstyrene and its derivatives such as the following (b-1) to (b-11) can be mentioned.
Further, the number of fluorine atoms in the monomer unit (B) is preferably 0 or 1.

From the viewpoint of easiness of preparing the polymer for forming the resist film and improving the breakability of the main chain of the polymer for forming the resist film when irradiated with ionizing radiation or the like, the monomer unit (B) is used. It is preferable that it does not contain a fluorine atom (that is, only the monomer unit (A) contains a fluorine atom), and more preferably it is a structural unit derived from α-methylstyrene. That, ^R 5 to R ⁹ in the formula (II) and Formula (IV), and, p and q are p = 5, q = 0, ^{R 5} is a methyl group, There are five ^{R 6} It is particularly preferable that all of them are hydrogen atoms, and R ⁸ and R ^{9 are hydrogen atoms.}

On the other hand, from the viewpoint of further suppressing the occurrence of collapse of the resist pattern when the polymer for forming a resist film is used for forming the resist pattern, the monomer unit (B) preferably contains a hydrogen atom. It is more preferable to contain one hydrogen atom, it is particularly preferable that it is a structural unit derived from fluoro-α-methylstyrene, and it is a structural unit derived from 4-fluoro-α-methylstyrene, that is, the formula. (II) and ^R 5 to R ⁹ in formula (IV), and, p and q are p = 5, q = 0, ^{R 5} is a methyl group, there are five para among ^{R 6} Most preferably, only fluorine, all four are hydrogen atoms, and R ⁸ and R ⁹ are hydrogen atoms.

[[Method for preparing polymer for forming resist film]]
The polymer for forming a resist film having the above-mentioned monomer unit (A) and monomer unit (B) is, for example, a monomer containing a monomer (a) and a monomer (b). It can be prepared by polymerizing the composition and then purifying the obtained polymer arbitrarily.

-Polymerization of monomeric composition-
Here, the monomer composition used for preparing the polymer for forming a resist film includes a monomer component containing the monomer (a) and the monomer (b), an arbitrary solvent, and a polymerization initiator. And a mixture of optionally added additives can be used. Then, the polymerization of the monomer composition can be carried out by using a known method. Among them, it is preferable to use cyclopentanone or the like as the solvent, and it is preferable to use a radical polymerization initiator such as azobisisobutyronitrile as the polymerization initiator.

The polymer obtained by polymerizing the monomer composition is not particularly limited, and after adding a good solvent such as tetrahydrofuran to a solution containing the polymer, a solution to which the good solvent is added is a solution such as methanol. It can be recovered by dropping the polymer in the poor solvent of No. 1 and coagulating the polymer.

-Purification of polymer-
The purification method used when purifying the obtained polymer is not particularly limited, and examples thereof include known purification methods such as a reprecipitation method and a column chromatography method. Above all, it is preferable to use the reprecipitation method as the purification method.
The purification of the polymer may be repeated a plurality of times.

Then, in the purification of the polymer by the reprecipitation method, for example, the obtained polymer is dissolved in a good solvent such as tetrahydrofuran, and then the obtained solution is mixed with a good solvent such as tetrahydrofuran and a poor solvent such as methanol. It is preferable to carry out by dropping into a solvent and precipitating a part of the polymer. In this way, if the polymer solution is dropped into the mixed solvent of the good solvent and the poor solvent to purify the polymer, the resist obtained by changing the types and mixing ratios of the good solvent and the poor solvent The molecular weight distribution, weight average molecular weight, and number average molecular weight of the film-forming polymer can be easily adjusted. Specifically, for example, the higher the proportion of the good solvent in the mixed solvent, the larger the molecular weight of the resist film-forming polymer precipitated in the mixed solvent.

When the polymer is purified by the reprecipitation method, the polymer precipitated in a mixed solvent of a good solvent and a poor solvent may be used as the polymer for forming the resist film, or it may be precipitated in the mixed solvent. A polymer that has not been used (that is, a polymer dissolved in a mixed solvent) may be used. Here, the polymer that did not precipitate in the mixed solvent can be recovered from the mixed solvent by using a known method such as concentrated dryness.

<< Resist pattern forming method (mask manufacturing method) >>
The resist pattern forming method (mask manufacturing method) may include (1) a step of exposing the resist film formed by the resist film forming method described above, and (2) a step of developing the exposed resist film. preferable.

<< Exposure process >>
In the above step (1), the resist film is irradiated with ionizing radiation or light to draw a desired pattern. A known drawing device such as an electron beam drawing device or a laser drawing device can be used for ionizing radiation or light irradiation.

<< Development process >>
In the above step (2), the resist film depicting the pattern is brought into contact with a developing solution to develop the resist film, and a resist pattern is formed on the workpiece (light-shielding layer in the photomask blanks). Here, the method of bringing the resist film into contact with the developing solution is not particularly limited, and known methods such as immersing the resist film in the developing solution and applying the developing solution to the resist film can be used. .. Then, the developed resist film is rinsed with a rinsing liquid.
In particular, the developing solution and rinsing solution include, for example, CF ₃ CFHCFHCF ₂ CF ₃ , CF ₃ CF ₂ CHCl ₂ , CClF ₂ CF ₂ CHClF, CF ₃ CF ₂ CF ₂ CF ₂ OCH ₃ , and C ₈ F ₁₈ . Fluorine-based solvent such as fluorocarbon; Alcohol such as methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol); Acetate ester having an alkyl group such as amyl acetate and hexyl acetate; Mixture of fluorine-based solvent and alcohol; Fluorine A mixture of a system solvent and an acetate having an alkyl group; a mixture of an alcohol and an acetate having an alkyl group; a mixture of a fluorine solvent and an alcohol and an acetate having an alkyl group; and the like can be used. For the combination of the developing solution and the rinsing solution, in consideration of the solubility of the resist composed of the above-mentioned polymer and the like, for example, a solvent having a higher resist solubility is used as a developing solution and a solvent having a lower resist solubility is used as a rinsing solution. be able to. Further, in selecting the developing solution, it is preferable to select a developing solution that does not dissolve the resist film before the step (1) is carried out. Further, when selecting the rinse solution, it is preferable to select a rinse solution that is easily mixed with the developer so that the rinse solution can be easily replaced with the developer.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the following description, "%" and "part" representing quantities are based on mass unless otherwise specified.
Then, in Examples 1 to 44 and Comparative Examples 1 to 8, (i) "weight average molecular weight, number average molecular weight and molecular weight distribution" and (ii) "adhesion between the resist film of the laminate and the light-shielding layer" were described. Each was measured and evaluated by the following methods.

<(I) Weight average molecular weight, number average molecular weight and molecular weight distribution>
The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer to be measured were measured by gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated.
Specifically, a gel permeation chromatograph (manufactured by Tosoh Corporation, HLC-8220) is used, and tetrahydrofuran is used as a developing solvent, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer to be measured are standardized. It was calculated as a polystyrene conversion value. Then, the molecular weight distribution (Mw / Mn) was calculated.

<(Ii) Adhesion between the resist film of the laminated body and the light-shielding layer>
The presence or absence of peeling of the formed resist pattern was observed, and the adhesion between the resist film and the light-shielding layer was evaluated according to the following criteria.
A: No peeling of resist pattern (good adhesion)
B: There is peeling of the resist pattern

(Example 1)
<Preparation of polymer (F3)>
3.0 g of α-chloroacrylic acid 2,2,2-trifluoroethyl as the monomer (a), 4.40 g of α-methylstyrene as the monomer (b), and cyclopentanone 1 as the solvent. A monomer composition containing .85 g and 0.006975 g of azobisisobutyronitrile as a polymerization initiator was placed in a glass container, the glass container was sealed and replaced with nitrogen, and the temperature was constant at 78 ° C. under a nitrogen atmosphere. The mixture was stirred in the tank for 6.0 hours. Then, the temperature was returned to room temperature, the inside of the glass container was released to the atmosphere, and then 10 g of tetrahydrofuran (THF) was added to the obtained solution. Then, a solution to which THF was added was added dropwise to 300 g of methanol to precipitate a polymer. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white coagulated product (polymer). Then, the obtained polymer was dissolved in 100 g of THF, and the obtained solution was added dropwise to a mixed solvent of 150 g of THF and 850 g of methanol (Methanol), and a white coagulated product (α-methylstyrene unit and α-chloroacrylic) was added. A polymer containing 2,2,2-trifluoroethyl acid units) was precipitated. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white polymer. The obtained polymer contained 50 mol% each of α-methylstyrene unit and α-chloroacrylic acid 2,2,2-trifluoroethyl unit.
Then, the weight average molecular weight, the number average molecular weight, and the molecular weight distribution of the obtained polymer were measured. The measured weight average molecular weight and molecular weight distribution are shown below.

<Preparation of positive resist composition>
The obtained polymer was dissolved in propylene glycol methyl ether acetate (PGMEA) as a solvent to prepare a resist solution (positive resist composition) having a polymer concentration of 2.5% by mass.

<Formation of resist pattern>
A chrome layer (thickness: 10 nm) was formed on a mask blank (quartz substrate (thickness: 1.0 mm)) having a diameter of 4 inches by using a spin coater (manufactured by Mikasa, MS-A150) to apply a positive resist composition. Thing) was applied on. Next, the applied positive resist composition was heated (prebaked) on a hot plate at a temperature of 150 ° C. for 10 minutes to form a resist film having a thickness of 50 nm on the mask blanks. Then, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer in the obtained resist film were measured by gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated. The electron beam drawing apparatus (Elionix Co., ELS-S50) by exposing at the optimum exposure amount of the resist film by using the _{(E op),} drawing a pattern. Then, as a developing solution for resist, a fluorine-based solvent (Mitsui / Dupont Fluorochemical Co., Ltd., Bertrel _{(CF 3 CFHCHFCF 2} CF ₃ )) was used for 1 minute of development treatment at a temperature of 23 ° C., and then as a rinsing solution. A resist pattern was formed by rinsing with a fluorine-based solvent (Mitsui-Dupont Fluorochemical Co., Ltd., Bartrel _{(CF 3 CFHCHFCF 2} CF _{3)) for 10 seconds.} Then, the adhesion between the resist film of the laminated body and the light-shielding layer was evaluated. The optimum exposure amount ( _Eop ) was set as appropriate. The lines (unexposed areas) and spaces (exposed areas) of the resist pattern were set to 20 nm, respectively.

<Measurement evaluation result>
The measured weight average molecular weight and molecular weight distribution, and the evaluation results of adhesion are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 58471, molecular weight distribution: 1.366
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 2)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 58576, molecular weight distribution: 1.359
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 3)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 58463, molecular weight distribution: 1.358
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 4)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 56442, molecular weight distribution: 1.378
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 5)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 58506, molecular weight distribution: 1.421
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 6)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 56460, molecular weight distribution: 1.453
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 7)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 52830, molecular weight distribution: 1.421
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 8)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 52726, molecular weight distribution: 1.437
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 9)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 51113, molecular weight distribution: 1.440
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 10)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 52669, molecular weight distribution: 1.494
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 11)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 1 minute was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 56999, molecular weight distribution: 1.426
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 12)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 51918, molecular weight distribution: 1.434
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 13)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 49804, molecular weight distribution: 1.451
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 14)
"Preparation of polymer (F3)", as in Example 1, except that in Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 1.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 60062, molecular weight distribution: 1.349
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48748, molecular weight distribution: 1.488
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 15)
<Preparation of polymer (F5)>
3. 3.0 g of α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl (ACAPFP) as the monomer (a) and α-methylstyrene (AMS) as the monomer (b). A monomer composition containing 4764 g, 0.0055 g of azobisisobutyronitrile as a polymerization initiator, and 1.6205 g of cyclopentanone as a solvent was placed in a glass container, and the glass container was sealed and replaced with nitrogen. In a nitrogen atmosphere, the mixture was stirred in a constant temperature bath at 78 ° C. for 6 hours. Then, the temperature was returned to room temperature, the inside of the glass container was released to the atmosphere, and then 10 g of tetrahydrofuran (THF) was added to the obtained solution. Then, the solution to which THF was added was added dropwise to 300 g of methanol to precipitate a polymer. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white coagulated product (polymer). Then, the obtained polymer (crude) was dissolved in 100 g of THF, and the obtained solution was added dropwise to a mixed solvent of 100 g of THF and 900 g of methanol (Methanol), and a white coagulated product (α-methylstyrene unit and α) was added dropwise. -Polymer containing 2,2,3,3,3-pentafluoropropyl unit of chloroacrylic acid) was precipitated. The obtained polymer contained 50 mol% of α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl units and 50 mol% of α-methylstyrene units.
Then, the weight average molecular weight, the number average molecular weight, and the molecular weight distribution of the obtained polymer were measured. The measured weight average molecular weight and molecular weight distribution are shown below.

<Preparation of positive resist composition>
The obtained polymer was dissolved in n-hexyl acetate as a solvent to prepare a resist solution (positive resist composition) having a polymer concentration of 4% by mass.

<Formation of resist pattern>
A chrome layer (thickness: 10 nm) was formed on a mask blank (quartz substrate (thickness: 1.0 mm)) having a diameter of 4 inches by using a spin coater (manufactured by Mikasa, MS-A150) to apply a positive resist composition. Thing) was applied on. Next, the applied positive resist composition was heated (prebaked) on a hot plate at a temperature of 150 ° C. for 10 minutes to form a resist film having a thickness of 50 nm on the mask blanks. Then, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer in the obtained resist film were measured by gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated. The electron beam drawing apparatus (Elionix Co., ELS-S50) by exposing at the optimum exposure amount of the resist film by using the _{(E op),} drawing a pattern. Then, as a developing solution for resist, a developing treatment was carried out at a temperature of 23 ° C. for 1 minute using a fluorine-based solvent (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{XF (registered trademark), CF 3 CFHCHFCF 2} CF _3). After that, a resist pattern was formed by rinsing with a fluorinated solvent as a rinsing solution (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{(CF 3 CFHCHFCF 2} CF _{3)) for 10 seconds.} Then, the presence or absence of peeling of the formed resist pattern was observed, and the adhesion between the resist film and the light-shielding layer was evaluated. The optimum exposure amount ( _Eop ) was set as appropriate. The lines (unexposed areas) and spaces (exposed areas) of the resist pattern were set to 20 nm, respectively.

<Measurement evaluation result>
The measured weight average molecular weight and molecular weight distribution, and the evaluation results of adhesion are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50473, molecular weight distribution: 1.416
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 16)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50876, molecular weight distribution: 1.414
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 17)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50787, molecular weight distribution: 1.417
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 18)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50146, molecular weight distribution: 1.422
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 19)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50791, molecular weight distribution: 1.415
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 20)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 49488, molecular weight distribution: 1.437
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 21)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47611, molecular weight distribution: 1.451
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 22)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48207, molecular weight distribution: 1.448
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 23)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47986, molecular weight distribution: 1.456
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 24)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 46987, molecular weight distribution: 1.463
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 25)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 1 minute was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48682, molecular weight distribution: 1.437
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 26)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 46706, molecular weight distribution: 1.462
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 27)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 45810, molecular weight distribution: 1.471
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 28)
"Preparation of polymer (F5)", as in Example 15, except that in Example 15, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 2.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 51522, molecular weight distribution: 1.403
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 43858, molecular weight distribution: 1.482
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 29)
<Preparation of polymer (F6)>
3.0 g of α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl (ACAPFP) as the monomer (a) and 4-fluoro-α-methylstyrene as the monomer (b) ( A monomer composition containing 3.23483 g of 4FAMS) and 0.00521 g of azobisisobutyronitrile as a polymerization initiator was placed in a glass container, and the glass container was sealed and replaced with nitrogen to create a 78 in a nitrogen atmosphere. The mixture was stirred in a constant temperature bath at ° C. for 6 hours. Then, the temperature was returned to room temperature, the inside of the glass container was released to the atmosphere, and then 10 g of tetrahydrofuran (THF) was added to the obtained solution. Then, the solution to which THF was added was added dropwise to 300 g of methanol to precipitate a polymer. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white coagulated product (polymer). Then, the obtained polymer (crude) was dissolved in 100 g of THF, and the obtained solution was added dropwise to a mixed solvent of 50 g of THF and 950 g of methanol (Methanol), and a white coagulated product (4-fluoro-α-methyl) was added dropwise. A polymer containing styrene units and α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl units) was precipitated. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white polymer. The obtained polymer contained 50 mol% of α-chloroacrylic acid 2,2,3,3,3-pentafluoropropyl units and 50 mol% of 4-fluoro-α-methylstyrene units.
Then, the weight average molecular weight, the number average molecular weight, and the molecular weight distribution of the obtained polymer were measured. The measured weight average molecular weight and molecular weight distribution are shown below.

<Preparation of positive resist composition>
The obtained polymer was dissolved in n-hexyl acetate as a solvent to prepare a resist solution (positive resist composition) having a polymer concentration of 4% by mass.

<Formation of resist pattern>
A chrome layer (thickness: 10 nm) was formed on a mask blank (quartz substrate (thickness: 1.0 mm)) having a diameter of 4 inches by using a spin coater (manufactured by Mikasa, MS-A150) to apply a positive resist composition. Thing) was applied on. Next, the applied positive resist composition was heated (prebaked) on a hot plate at a temperature of 150 ° C. for 10 minutes to form a resist film having a thickness of 50 nm on the mask blanks. Then, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer in the obtained resist film were measured by gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated. The electron beam drawing apparatus (Elionix Co., ELS-S50) by exposing at the optimum exposure amount of the resist film by using the _{(E op),} drawing a pattern. Then, as a developing solution for resist, a developing treatment was carried out at a temperature of 23 ° C. for 1 minute using a fluorine-based solvent (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{XF (registered trademark), CF 3 CFHCHFCF 2} CF _3). After that, a resist pattern was formed by rinsing with a fluorinated solvent as a rinsing solution (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{(CF 3 CFHCHFCF 2} CF _{3)) for 10 seconds.} Then, the presence or absence of peeling of the formed resist pattern was observed, and the adhesion between the resist film and the light-shielding layer was evaluated. The optimum exposure amount ( _Eop ) was set as appropriate. The lines (unexposed areas) and spaces (exposed areas) of the resist pattern were set to 20 nm, respectively.

<Measurement evaluation result>
The measured weight average molecular weight and molecular weight distribution, and the evaluation results of adhesion are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48317, molecular weight distribution: 1.289
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 30)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 160 ° C. for 3 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48294, molecular weight distribution: 1.288
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 31)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 160 ° C. for 5 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47739, molecular weight distribution: 1.292
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 32)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 160 ° C. for 10 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47127, molecular weight distribution: 1.299
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 33)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 170 ° C. for 1 minute instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47174, molecular weight distribution: 1.284
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 34)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 170 ° C. for 3 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48079, molecular weight distribution: 1.293
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 35)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 170 ° C. for 5 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47218, molecular weight distribution: 1.302
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 36)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 170 ° C. for 10 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 46546, molecular weight distribution: 1.310
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 37)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 180 ° C. for 1 minute instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 48008, molecular weight distribution: 1.291
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 38)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 180 ° C. for 3 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47597, molecular weight distribution: 1.301
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 39)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 180 ° C. for 5 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 46227, molecular weight distribution: 1.318
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 40)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 180 ° C. for 10 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 46266, molecular weight distribution: 1.314
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 41)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 190 ° C. for 1 minute instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47934, molecular weight distribution: 1.299
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 42)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 190 ° C. for 3 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47165, molecular weight distribution: 1.306
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 43)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 190 ° C. for 5 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 45937, molecular weight distribution: 1.318
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Example 44)
In Example 29, "Preparation of Polymer (F6)", except that the prebaking was performed by heating at 190 ° C. for 10 minutes instead of the prebaking by heating at 150 ° C. for 10 minutes. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 3.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 47311, molecular weight distribution: 1.284
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 45219, molecular weight distribution: 1.323
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: A (good adhesion)

(Comparative Example 1)
<Preparation of polymer (F0)>
3.0 g of methyl α-chloroacrylate and 6.88 g of α-methylstyrene as monomers, 2.47 g of cyclopentanone as a solvent, and 0.01091 g of azobisisobutyronitrile as a polymerization initiator. The monomer composition containing the above was placed in a glass container, the glass container was sealed and replaced with nitrogen, and the mixture was stirred in a constant temperature bath at 78 ° C. for 6.5 hours under a nitrogen atmosphere. Then, the temperature was returned to room temperature, the inside of the glass container was released to the atmosphere, and then 30 g of tetrahydrofuran (THF) was added to the obtained solution. Then, a solution to which THF was added was added dropwise to 300 g of methanol to precipitate a polymer. Then, the solution containing the precipitated polymer was filtered through a Kiriyama funnel to obtain a white coagulated product (polymer). The obtained polymer contained 50 mol% each of α-methylstyrene unit and α-methylchloroacrylate unit.
Then, the weight average molecular weight, the number average molecular weight, and the molecular weight distribution of the obtained polymer were measured. The measured weight average molecular weight and molecular weight distribution are shown below.

<Preparation of positive resist composition>
The obtained polymer was dissolved in anisole as a solvent to prepare a resist solution (positive resist composition) having a polymer concentration of 2.5% by mass.

<Formation of resist pattern>
A chrome layer (thickness: 10 nm) was formed on a mask blank (quartz substrate (thickness: 1.0 mm)) having a diameter of 4 inches by using a spin coater (manufactured by Mikasa, MS-A150) to apply a positive resist composition. Thing) was applied on. Next, the applied positive resist composition was heated (prebaked) on a hot plate at a temperature of 150 ° C. for 10 minutes to form a resist film having a thickness of 50 nm on the mask blanks. Then, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer in the obtained resist film were measured by gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated. The electron beam drawing apparatus (Elionix Co., ELS-S50) by exposing at the optimum exposure amount of the resist film by using the _{(E op),} drawing a pattern. Then, as a developing solution for resist, a developing treatment was carried out at a temperature of 23 ° C. for 1 minute using a fluorine-based solvent (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{XF (registered trademark), CF 3 CFHCHFCF 2} CF _3). After that, a resist pattern was formed by rinsing with a fluorinated solvent as a rinsing solution (Mitsui-Dupont Fluorochemical Co., Ltd., Bertrel _{(CF 3 CFHCHFCF 2} CF _{3)) for 10 seconds.} Then, the presence or absence of peeling of the formed resist pattern was observed, and the adhesion between the resist film and the light-shielding layer was evaluated. The optimum exposure amount ( _Eop ) was set as appropriate. The lines (unexposed areas) and spaces (exposed areas) of the resist pattern were set to 20 nm, respectively.

<Measurement evaluation result>
The measured weight average molecular weight and molecular weight distribution, and the evaluation results of adhesion are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 52766, molecular weight distribution: 1.882
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 2)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 49993, molecular weight distribution: 1.940
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 3)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 5 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50057, molecular weight distribution: 1.927
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 4)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 160 ° C. for 10 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50172, molecular weight distribution: 1.925
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 5)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 1 minute was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 50504, molecular weight distribution: 1.921
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 6)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 170 ° C. for 3 minutes was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47222, molecular weight distribution: 1.967
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 7)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 180 ° C. for 1 minute was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 51181, molecular weight distribution: 1.908
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

(Comparative Example 8)
Similar to Comparative Example 1, "Preparation of polymer (F0)", except that in Comparative Example 1, instead of prebaking by heating at 150 ° C. for 10 minutes, prebaking by heating at 190 ° C. for 1 minute was performed. "Preparation of positive resist composition" and "formation of resist pattern" were performed, and the same measurement or evaluation was performed. The results are shown below and in Table 4.
(I) Weight average molecular weight and molecular weight distribution of the prepared polymer Weight average molecular weight: 54734, molecular weight distribution: 1.842
(Ii) Weight average molecular weight and molecular weight distribution of polymer in resist film of laminate Weight average molecular weight: 47852, molecular weight distribution: 1.969
(Iii) Adhesion between the resist film of the laminated body and the light-shielding layer Adhesion evaluation result: B (low adhesion)

From Tables 1 to 4, the laminates of Examples 1 to 44 in which the resist film containing the predetermined polymer having a predetermined monomer unit was formed were compared with the laminates of Comparative Examples 1 to 8 and resisted. It can be seen that the adhesion between the film and the light-shielding layer can be improved.

According to the laminate of the present invention, the adhesion between the resist film and the light-shielding layer can be improved.

10 Substrate 20 Light-shielding layer 30 Photomask Blanks 40 Resist film 50 Laminated body 60 Electron beam 100 Photomask

Claims (10)

A laminate comprising a substrate, a light-shielding layer formed on the substrate, and a resist film formed on the light-shielding layer.
The resist film contains a polymer and contains
The polymer is
The following general formula (I):

(In formula (I), R ¹ is an alkyl group substituted with a chlorine atom, a fluorine atom or a fluorine atom, R ² is a pentafluoroalkyl group , and R ³ and R ⁴ are hydrogen atoms and fluorine. Atomic, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, which may be the same or different from each other.)
The monomer unit (A) represented by
The following general formula (II):

In formula (II), R ⁵ , R ⁶ , R ⁸ and R ⁹ are hydrogen atoms, fluorine atoms, unsubstituted alkyl groups or alkyl groups substituted with fluorine atoms, which may be the same or different from each other. Often, R ⁷ is an alkyl group substituted with a hydrogen atom, an unsubstituted alkyl group or a fluorine atom, and p and q are integers of 0 or more and 5 or less, and p + q = 5).
In formula that have a and monomer units (B) is a laminate. The laminate according to claim 1, wherein R ^{1 is a chlorine atom.} Before Symbol R ³ and R ⁴ are a hydrogen atom or an unsubstituted alkyl group, it may be the same or different from each other, laminate according to claim 2. Wherein p is 1 to 5 integer, R ⁵ and R ⁷ to R ⁹ is Ru alkyl der hydrogen atom or unsubstituted laminate according to any one of claims 1 to 3. The laminate according to claim 4, wherein the number of fluorine atoms in the monomer unit (B) is 0 or 1. The laminate according to any one of claims 1 to 5, wherein R ² is a 2,2,3,3,3-pentafluoropropyl group. The laminate according to any one of claims 1 to 6 , wherein the monomer unit (B) is a structural unit derived from α-methylstyrene or a structural unit derived from 4-fluoro-α-methylstyrene. The laminate according to any one of claims 1 to 7 , wherein the polymer has a weight average molecular weight of 59000 or less. The laminate according to any one of claims 1 to 8 , wherein the polymer has a weight average molecular weight of 43,800 or more. The laminate according to any one of claims 1 to 9 , wherein the polymer has a molecular weight distribution (Mw / Mn) of 1.50 or less.

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