JP3042618B2 - (Meth) acrylate derivative having lactone structure, polymer, photoresist composition, and pattern forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel (meth) acrylate derivative and a polymer thereof, and more particularly to a method for producing a resin used for a photoresist material that uses deep ultraviolet light having a wavelength of 220 nm or less as an exposure light. It relates to useful compounds.

[0002]

2. Description of the Related Art In the field of the manufacture of various electronic devices that require microfabrication on the order of half microns, typified by semiconductor devices, there is an increasing demand for higher density and higher integration of devices. . Therefore, the demand for photolithography technology for forming fine patterns has become more and more severe.

In particular, the use of photolithography using an ArF excimer laser (193 nm) has recently been considered for the manufacture of a DRAM having an integration degree of 1 Gbit or more, which requires a processing technology of 0.18 μm or less [ Donald C. Hoffer et al., Journal of Photopolymer Science and Technology (Journ
al of Photopolymer Science
e and Technology), Volume 9 (No. 3),
387-397 (1996)]. Therefore, ArF
Development of a resist material corresponding to photolithography using light is desired.

In the development of this ArF exposure resist, the cost performance of the laser is improved due to the short life of the gas, which is the material of the laser, and the high cost of the laser itself. Needs to be satisfied. For this reason, there is a high demand for high sensitivity in addition to high resolution corresponding to miniaturization of processing dimensions.

As a method for increasing the sensitivity of a resist, a chemically amplified resist using a photoacid generator as a photosensitive agent is well known. For example, a typical example is disclosed in
No. 7660 describes a resist composed of a combination of triphenylsulfonium hexafluoroacenate and poly (p-tert-butoxycarbonyloxy-α-methylstyrene). Such chemically amplified resists are currently widely used in KrF excimer laser resists [for example, Hiroshito, C.I. Grant Wilson, American Chemical Society Symposium Series 242, pp. 11-23
P. (1984)]. A characteristic of the chemically amplified resist is that a proton acid generated by light irradiation from a photoacid generator as a contained component causes an acid-catalyzed reaction with a resist resin or the like by heat treatment after exposure. In this way, the photoreaction efficiency (reaction per photon) is significantly higher than that of a conventional resist having less than 1. At present, most of the developed resists are chemically amplified.

[0006]

However, in the case of lithography using short-wavelength light of 220 nm or less typified by ArF excimer laser light, conventional materials are not sufficient for a resist for forming a fine pattern. A new characteristic that cannot be obtained, that is, high transparency to exposure light of 220 nm or less and dry etching resistance are required.

Conventional g-line (438 nm) and i-line (365)
As a resin material for a KrF excimer laser (248 nm), a resin having an aromatic ring in a structural unit such as a novolak resin or poly (P-vinylphenol) is mainly used as a resin component. The etching resistance of the resin could be maintained by the dry etching resistance of the ring. However, the resin having an aromatic ring has extremely strong light absorption for light having a wavelength of 220 nm or less. Therefore, most of the exposure light is absorbed on the resist surface, and the exposure light does not transmit to the substrate, so that a fine resist pattern cannot be formed, and the conventional resin is used as it is for photolithography using short wavelength light of 220 nm or less as it is. Not applicable. Therefore, it does not contain an aromatic ring and has etching resistance,
There is a strong need for a resist material that is transparent to wavelengths of nm or less.

As a polymer compound having transparency to ArF excimer laser light (193 nm) and resistance to dry etching, a copolymer having an adamantyl methacrylate unit which is an alicyclic polymer [Takechi et al.
Null of Photopolymer Science and Technology (Journal of Photopol)
ymer Science and Technology
gy), 5 (3), pages 439-446 (1992)
Years)] and copolymers having isobornyl methacrylate units [R. D. RD Allen et al., Jar.
Null of Photopolymer Science and Technology (Journal of Photopol)
ymer Science and Technology
gy), Volume 8 (No. 4), pp. 623-636 (1995)
Year 9), and Volume 9 (No. 3), pp. 465-474 (19
1996)] has been proposed.

However, the (meth) acrylate derivative having an alicyclic group used in the former resin does not have a polar group (for example, a carboxyl group or a hydroxyl group) having substrate adhesion. Therefore, a homopolymer of a monomer having an alicyclic group has strong hydrophobicity and poor adhesion to a substrate to be processed (for example, a silicon substrate), and it is difficult to form a uniform coating film with good reproducibility. Furthermore, a pattern cannot be formed by exposure because there is no residue capable of expressing a difference in solubility between before and after exposure in an adamantane-containing residue, an isobonyl-containing residue, or a menthyl-containing residue unit having dry etching resistance. Therefore, the former resin is the first resin component of a resist to be a copolymer with a comonomer such as t-butyl methacrylate or tetrahydromethacrylate, which can exhibit a difference in solubility, or a co-monomer having substrate adhesion, such as methacrylic acid. Available as However, the comonomer content is required to be about 50 mol%, and the dry etching resistance of the comonomer unit is extremely low, so that the dry etching resistance effect by the alicyclic group is significantly reduced, and the practicality as a dry etching resistant resin is reduced. poor.

Therefore, a new resist resin material having high light transparency to light of 220 nm or less, high etching resistance, and improved substrate adhesion has been desired.

[0011]

Means for Solving the Problems The inventor of the present invention has made intensive studies to achieve the above object, and has completed the present invention.
That is, the present invention is as follows. 1. A (meth) acrylate derivative represented by the general formula (1).

[0012]

Embedded image (In the above formula, R ¹ and R ² represent a hydrogen atom or a methyl group.) A polymer obtained by polymerizing the (meth) acrylate derivatives described in 1 above or copolymerizing the (meth) acrylate derivative described in 1 above with another polymerizable compound. 3. 3. The polymer according to the above 2, wherein the polymer is represented by the general formula (2), and has a weight average molecular weight of 2,000 to 200,000.

[0013]

Embedded image (In the above formula, R ¹ , R ² , R ³ , and R ⁵ are a hydrogen atom or a methyl group, R ⁴ is a group capable of decomposing by an acid, and a bridged cyclic carbon having 7 to 13 carbon atoms having a group decomposing by an acid. R6 represents a hydrogen atom or a bridged cyclic hydrocarbon group having a carbon number of 7 to 13 having a carboxyl group;
2 represents a hydrocarbon group. x, y, z are x + y +
z is an arbitrary number satisfying 0, 0 <x ≦ 1, 0 ≦ y <1, and 0 ≦ z <1. ) 4. 70 to 9 of at least one of the polymers described in the above 2 to 3
A photoresist composition containing 9.8% by weight and 0.2 to 30% by weight of a photoacid generator that generates an acid upon exposure. 5. 5. A method comprising applying the photoresist composition described in 4 above on a substrate to be processed, exposing with light having a wavelength of 180 to 220 nm or less, performing baking, and performing development. Pattern formation method. 6. 6. The pattern forming method according to the above item 5, wherein the exposure light is ArF excimer laser light.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the general formula (1), R ¹ , R
² is a hydrogen atom or a methyl group.

In the general formula (2), R ¹ , R ² , R
³ , R ⁵ is a hydrogen atom or a methyl group. R ⁴ has a group decomposed by an acid and a group having 7 carbon atoms having a group decomposed by an acid
A bridged cyclic hydrocarbon group having 13 to 13 carbon atoms or a bridged cyclic hydrocarbon group having 7 to 13 carbon atoms having a carboxyl group.

A specific example of a group decomposed by an acid is t-
Butyl group, tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-propoxyethyl group, 3-oxo Cyclohexyl group, 2-methyl-2-adamantyl group, 8-
Methyl-8-tricyclo [5.2.1.0 ^2,6 ] decyl group, or 1,2,7,7-tetramethyl-2-norbornyl group, 2-acetoxymenthyl group, 2-hydroxymenthyl group, 1-methyl-1 -Cyclohexylethyl group and the like, but are not limited thereto. A bridged cyclic hydrocarbon group having 7 to 13 carbon atoms having a group decomposed by an acid or a carbon atom having 7 to 1 carbon atoms having a carboxyl group;
Specific examples of the bridged cyclic hydrocarbon group of No. 3 include a tricyclo [5.2.1.0 ^{2 , 6} ] decylmethyl group having a carboxyl group or an ester group as shown in Table 1, and a tricyclo [5.2.1.
0 ^2,6] decyl group, an adamantyl group, a norbornyl group, methyl norbornyl group, isobornyl group, tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecyl group, methyl tetracyclo [4.4.0.1 ^{2, 5} .1 ^7,10 ] dodecyl group and the like, but are not limited thereto.

[0017]

[Table 1] R ^{7 in} Table 1 is a group decomposed by an acid, and specific examples include a t-butyl group, a tetrahydropyran-2-yl group,
Tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1
-Butoxyethyl group, 1-propoxyethyl group, 3-oxocyclohexyl group, 2-methyl-2-adamantyl group, 8-methyl-8-tricyclo [5.2.1.0 ^2,6 ] decyl group, or 1,2,7 , 7-tetramethyl-2-norbornyl, 2-acetoxymenthyl, 2-hydroxymenthyl, 1-methyl-1-cyclohexylethyl, and the like, but is not limited thereto.

R⁶ Is a hydrogen atom or a group having 1 to 12 carbon atoms.
Hydrocarbon group, specifically, methyl group, ethyl group,
n-propyl group, isopropyl group, n-butyl group, iso-
Butyl group, t-butyl group, cyclohexyl group, tricycl
B [5.2.1.0^2,6] Decyl group, adamantyl group, norboni
Group, isobornyl group, tetracyclo [4.4.0.1^2,5.1
^7,10And the like, but are not limited thereto.
It is not something to be done.

As described above, one of the present invention is a photoresist composition containing the polymer and a photoacid generator. The photoacid generator used in the present invention is preferably a photoacid generator that generates an acid by light irradiation of 400 nm or less, preferably in the range of 180 nm to 220 nm, and more preferably from the polymer of the present invention described above. Any photoacid generator may be used as long as the composition can be sufficiently dissolved in an organic solvent and the solution can form a uniform coating film by a film forming method such as spin coating. Moreover, you may use individually or in mixture of 2 or more types.

Examples of usable photoacid generators include, for example, Journal of the Organic Chemistry.
emiry) 43, 15, No. 3055-305
8 (1978). V. Crivello
(JV Crivello) et al., And other onium salts (e.g., compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, and ammonium salts) and the like. , 6-dinitrobenzyl esters [O. O. Nalamasu et al., SPIE Proceeding, 1262, 32 (1990)], 1,
2,3-tri (methanesulfonyloxy) benzene [Takumi Ueno et al., Proceeding of PME'8]
9, Kodansha, pp. 413-424 (1990)], Hei 5
And sulfosuccinimide disclosed in US Pat.

The content of the photoacid generator is usually from 0.2 to 30 parts by weight, preferably from 1 to 15 parts by weight, based on 100 parts by weight of all the components including itself. When the content is 0.2 parts by weight or more, sufficient sensitivity can be obtained, and the pattern can be easily formed. When the amount is 30 parts by weight or less, it is easy to form a uniform coating film, and it is difficult to generate residue (scum) after development.

The photoresist composition of the present invention is applied in the form of a solution. Preferred as a solvent used in this method is an organic solvent in which a component composed of a polymer and a photoacid generator is sufficiently dissolved, and the solution is capable of forming a uniform coating film by a method such as a spin coating method. Any solvent may be used. Moreover, you may use individually or in mixture of 2 or more types. Specifically, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monoethyl ether acetate, Methyl lactate, ethyl lactate, acetic acid 2
-Methoxybutyl, 2-ethoxyethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, N-methyl-2-pyrrolidinone, cyclohexanone, cyclopentanone, cyclohexanol , Methyl ethyl ketone,
1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether However, it is needless to say that the present invention is not limited to these.

The "basic" components of the photoresist composition of the present invention are the above-mentioned polymer and photoacid generator, and are used by dissolving them in the above-mentioned solvent.
Other components such as a dye, a stabilizer, a coating improver, and a dye may be added.

[0024]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

Example 1 Synthesis of 5-Acryloyloxy-2,6-norbornanecarbolactone (an acrylate in which R ¹ and R ² are hydrogen atoms in the general formula (1)).

[0026]

Embedded image5-Hydroxy-2,6-norbornanecarbolactone (HBH
enbest et al. Chem. Soc. , 221-2
26g (1959)) 10g (0.0653mo)
l), N, N-dimethylaniline 9.49 g, phenothi
Dissolve 20 mg of azine in 60 ml of dry THF and cool with ice
You. 6.5 g of acryloyl chloride was added thereto in dry THF10.
The solution dissolved in ml is dropped. 2 hours at room temperature under ice cooling
After stirring for 3 hours, the filtrate is concentrated under reduced pressure. A
Add 250 ml of ter, add 200 ml of 0.5N hydrochloric acid, and saturate
Saline, 3% NaHCO3 aqueous solution 200ml, saturated salt
Wash with water, then water. Dry the ether layer with MgSO4
Thereafter, the ether was distilled off under reduced pressure, and the precipitated white crystals were removed.
5.38 g of the target product by washing with sun 80 ml x 2
(White solid, yield 40%). Melting point: 96 ° C; 1H-
NMR (CDCl3) [delta] 1.66 (1H, d), 1.78
(1H, d), 1.99-2.11 (2H, m), 2.5
3-2.62 (2H, m), 3.18-3.25 (1H,
m), 4.59 (1H, d), 4.64 (1H, s),
5.89 (1H, dd), 6.11 (1H, dd), 6.
43 (1H, dd); IR (KBr) 2880,298
0 (νC−H), 1712, 1773 (νC = O), 1
618, 1630 (νC = C), 1186, 1205
(ΝC-O) cm^-1 Example 2 5-Methacryloyloxy-2,6-norbornanecarbolactone (general
In the formula (1), R ¹ Is a methyl group, R^Two Is a hydrogen atom
Synthesis of certain methacrylates).

[0027]

Embedded image It was synthesized in the same manner as in Example 1 except that methacryloyl chloride was used instead of acryloyl chloride (yield: 20).
%). ¹ H-NMR (CDCl3) δ 1.62 (1H,
d), 1.75 (1H, d), 1.92 (3H, s),
1.95-2.16 (2H, m), 2.53-2.66 (2
H, m), 3.20-3.28 (1H, m), 4.59
(1H, d), 4.65 (1H, s), 5.62 (1H,
dd), 6.10 (1H, dd); IR (KBr) 28
80, 2982 (νC-H), 1715, 1780 (ν
C = O), 1630 (νC = C), 1156, 1178
(ΝC-O) cm ^-1 Example 3 2-Methyl-6-acryloyloxy-2,6-norbornanecarbolactone
(In general formula (1), acrylate in which R ¹ is a hydrogen atom and R ² is a methyl group).

[0028]

Embedded image 6-hydr instead of 5-Hydroxy-2,6-norbornanecarbolactone
oxy-2,6-norbornane-carbolactone (S. Beckma
nn et al., Chem. Ber. Vol. 94, pp. 48-58 (1
961)) except that was used (synthesis 30%). IR (KBr) 2880, 29
82 (νC-H), 1716, 1774 (νC = O),
1619, 1629 (νC = C), 1188, 1208
(ΝC-O) cm ^-1 .

Example 4 A polymer having the following structure (in the general formula (2), R¹ , R
^Two , R^Three Is a hydrogen atom, R ^Four Is t-butoxycarbonyl
Toracyclo [4.4.0.1^2,5.1^7,10A dodecyl group, x = 0.
7, y = 0.3, z = 0).

[0030]

Embedded image In a 100 ml eggplant flask equipped with a reflux tube, 2.5 g of the acrylate obtained in Example 1 and 1.71 g of t-butoxycarbonyltetracyclododecyl acrylate were dissolved in 23 ml of dry tetrahydrofuran, and AIBN11 was added thereto.
3 mg (30 mmol·l ⁻¹ ) is added, and the mixture is stirred at 60 to 65 ° C. under an argon atmosphere. After cooling for 2 hours, the reaction mixture was poured into 400 ml of methanol, and the deposited precipitate was separated by filtration. Further, reprecipitation purification was performed once again to obtain 1.98 g of the desired product (yield: 47%). The copolymerization ratio at this time is
It was 70:30 from the integration ratio of ¹ H-NMR (x =
0.7, y = 0.3). The weight average molecular weight (Mw) by GPC analysis was 10,800 (in terms of polystyrene), and the degree of dispersion (Mw / Mn) was 1.88.

Examples 5 and 6 Polymerization was carried out in the same manner as in Example 4 except that the charging ratio of the monomers was changed. Table 2 shows the charging ratio of the monomers, the copolymerization ratio of the polymer (x / y), and the weight average molecular weight of the obtained copolymer.

[0032]

[Table 2] Examples 7 and 8 Polymerization was carried out in the same manner as in Example 4 except that the amount (concentration) of AIBN was changed. Table 3 shows the copolymerization ratio (x / y) of the polymer, the weight average molecular weight of the obtained polymer, and the like.

[0033]

[Table 3] Example 9 A polymer having the following structure (in the general formula (2), R ¹ , R ²
But a hydrogen atom, R ³ is a methyl group, R ⁴ is tetrahydropyranyloxy carbonyl tetracyclo [4.4.0.1 ^{2, 5.}
1 ^7,10 ] dodecyl group, x = 0.7, y = 0.3, z =
Synthesis of 0).

[0034]

Embedded image Synthesis was performed in the same manner as in Example 4 except that tetrahydropyranyloxycarbonyltetracyclododecyl methacrylate was used instead of t-butoxycarbonyltetracyclododecyl acrylate. Yield 52%, Mw = 12
000, Mw / Mn = 1.75.

Example 10 A polymer having the following structure (in the formula (2), R ¹ , R ²
Is a hydrogen atom, R ³ is a methyl group, R ⁴ is 2-methyl-2-
Synthesis of adamantyl group, x = 0.7, y = 0.3, z = 0).

[0036]

Embedded image The synthesis was carried out in the same manner as in Example 4 except that 2-methyl-2-adamantyl methacrylate was used instead of t-butoxycarbonyltetracyclododecyl acrylate. Yield 42%, Mw = 9500, Mw / Mn = 1.9
6 Example 11 A polymer having the following structure (in the general formula (2), R ¹ , R ²
Is a hydrogen atom, R ² is a methyl group, R ⁴ is t-butyl methacrylate, x = 0.7, y = 0.3, z = 0).

[0037]

Embedded image Synthesis was performed in the same manner as in Example 4 except that t-butyl methacrylate was used instead of t-butoxycarbonyltetracyclododecyl acrylate. Yield 60%, Mw =
8400, Mw / Mn = 1.74 Example 12 A polymer having the following structure (in the general formula (2), R ¹ , R
² , R ³ is a hydrogen atom, R ⁴ is a t-butoxycarbonylnorbornyl group, x = 0.7, y = 0.3, z = 0).

[0038]

Embedded image Synthesis was carried out in the same manner as in Example 4, except that t-butoxycarbonylnorbornyl acrylate was used instead of t-butoxycarbonyltetracyclododecyl acrylate. Yield 44%, Mw = 9100, Mw / Mn = 1.7
2 Example 13 A polymer having the following structure (in the general formula (2), R ¹ , R ³
But a hydrogen atom, R ² is a methyl group, R ⁴ is t- butoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecyl group,
x = 0.7, y = 0.3, z = 0).

[0039]

Embedded image Synthesis was performed in the same manner as in Example 4 except that the acrylate obtained in Example 3 was used instead of the acrylate obtained in Example 1. Yield 60%, Mw = 11300, Mw / Mn =
1.88.

Example 14 A polymer having the following structure (in the general formula (2), R¹ , R
^Two , R^Three Is a hydrogen atom, R ^FourIs t-butoxycarbonyl
Toracyclo [4.4.0.1^2,5.1^7,10A dodecyl group, R5 is
A tyl group, R6 is a hydrogen atom, x = 0.6, y = 0.3, z
= 0.1).

[0041]

Embedded image In a 100 ml eggplant flask equipped with a reflux tube, 3 g of the acrylate obtained in Example 1, 2.39 g of t-butoxycarbonyltetracyclododecyl acrylate, and 0.207 g of methacrylic acid were dissolved in 30 ml of dry tetrahydrofuran, and 147 mg of AIBN (30 mmol. l ^-1
In addition, the mixture is stirred at 60 to 65 ° C. under an argon atmosphere. After cooling for 2 hours, the reaction mixture is poured into 500 ml of methanol, and the deposited precipitate is separated by filtration. Further, re-precipitation purification was performed once again to obtain 2.35 g of the desired product (yield: 42).
%). The copolymerization ratio at this time was 6 based on the integration ratio of 1H-NMR.
0:30:10 (x = 0.6, y = 0.3, z
= 0.1). Mw = 9700, Mw / Mn = 1.74.

Example 15 A polymer having the following structure (in the general formula (2), R ¹ , R
^2, R ^3, R ⁵ is a hydrogen atom, R ⁴ is t- butoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecyl radical, R
⁶ is a tricyclodecyl group, x = 0.6, y = 0.3, z
= 0.1).

[0043]

Embedded image Synthesis was performed in the same manner as in Example 14 except that tricyclodecyl acrylate (trade name: FA-513A, manufactured by Hitachi Chemical Co., Ltd.) was used instead of methacrylic acid. Yield 57
%, Mw = 13700, Mw / Mn = 2.13 Example 16 A polymer having the following structure (in the general formula (2), R ¹ , R ²
Is a hydrogen atom group, x = 1, y = z = 0).

[0044]

Embedded image In a 50 ml eggplant flask equipped with a reflux tube, 3 g of the acrylate obtained in Example 1 was dried in 16 ml of tetrahydrofuran.
Dissolved in AIBN 79 mg (30 mmol
-1), and the mixture is stirred at 60 to 65 ° C. under an argon atmosphere. After 1 hour, the reaction mixture was allowed to cool, and methanol
and the precipitated precipitate is filtered off. Further, reprecipitation purification was performed once again to obtain 1.8 g of the desired product (yield: 6).
0%). Mw = 7100, Mw / Mn = 2.05.

Example 17 A polymer having the following structure (in the formula (2), R ¹ and R ²
Is a hydrogen atom, R ³ is a methyl group, R ⁴ is a 2-acetoxymenthyl group, x = 0.7, y = 0.3, z = 0).

[0046]

Embedded image Synthesis was performed in the same manner as in Example 4 except that 2-acetoxymenthyl methacrylate (described in Japanese Patent Application No. 08-335603) was used instead of t-butoxycarbonyltetracyclododecyl acrylate. Yield 52%, Mw = 86
00, Mw / Mn = 1.77.

Example 18 (Evaluation of etching resistance of polymer) 2 g of the polymer (resin) obtained in Example 5 was dissolved in 10 g of propylene glycol monomethyl ether acetate, and then filtered using a 0.2 μm Teflon filter. . Next, spin coating was performed on a 3-inch silicon substrate, and baked on a hot plate at 90 ° C. for 60 seconds to form a thin film having a thickness of 0.7 μm. The obtained membrane was coated with DEM4 manufactured by Nidec Anelva.
The etching rate for CF4 gas was measured using a 51 reactive ion etching (RIE) apparatus (etching conditions: Power = 100 W, pressure = 5 Pa,
(Gas flow rate = 30 sccm). Table 4 shows the results. Similarly, the etching rate of the polymer (resin) obtained in Example 15 was measured. As comparative examples, novolak resist (PFI-15A manufactured by Sumitomo Chemical Co., Ltd.), poly (p-vinylphenol) used as a base resin of KrF resist, and a resin having no bridged cyclic hydrocarbon group in its molecular structure. The results for a poly (methyl methacrylate) coating film are also shown. The etching rate was standardized for the novolak resist.

[0048]

[Table 4] The above results show that the polymer (resin) of the present invention has a low etching rate with respect to CF ₄ gas and is excellent in dry etching resistance.

Example 19 (Evaluation of Transparency of Polymer) 2.5 g of the polymer (resin) obtained in Example 5 was dissolved in 10 g of propylene glycol monomethyl ether acetate, and then filtered using a 0.2 μm Teflon filter. did. Next, spin coating was performed on a 3-inch quartz substrate, and baked on a hot plate at 90 ° C. for 60 seconds to form a thin film having a thickness of 1 μm. This thin film is subjected to A-ray spectroscopy using an ultraviolet-visible spectrophotometer.
193.4 nm which is the center wavelength of rF excimer laser light
Was measured. Similarly, the polymer (resin) obtained in Example 15 was measured. The transmittance of the polymer obtained in Example 5 was 54% / μm, and that of the polymer of Example 15 was 55% / μm. From these results, it was confirmed that the polymer of the present invention exhibited transparency usable as a single-layer resist.

Example 20 (Evaluation of Patterning of Resist Using Polymer) A resist having the following composition was prepared. (A) Polymer (Example 5): 2 g (b) Photoacid generator (triphenylsulfonium triflate (TPS)): 0.02 g (c) Propylene glycol monomethyl ether acetate: 11.5 g Filtration was performed using a 2 μm Teflon filter to prepare a resist. The above resist was spin-coated on a 4-inch silicon substrate and baked on a hot plate at 130 ° C. for 1 minute to form a thin film having a thickness of 0.4 μm. Then, the wafer having the film formed thereon was allowed to stand in a contact-type exposure experiment machine sufficiently purged with nitrogen. A mask in which a pattern of chrome was drawn on a quartz plate was adhered to the resist film, and ArF excimer laser light was irradiated through the mask. Immediately thereafter, hot-press at 110 ° C for 60 seconds.
And immersion in a 2.38% TMAH aqueous solution at a liquid temperature of 23 ° C. for 60 seconds, followed by immersion.
Rinsing treatment was performed with pure water for 2 seconds. As a result, only the exposed portion of the resist film was dissolved and removed in the developing solution to obtain a positive pattern. Similarly, a resist using the polymer obtained in Example 15 was similarly evaluated. Table 5 shows the results of sensitivity and resolution.

[0051]

[Table 5] From the above results, it was found that the photoresist material using the polymer of the present invention had excellent resolution characteristics. In addition, since there was no phenomenon such as pattern peeling, it was confirmed that the substrate had excellent adhesiveness.

[0052]

As is apparent from the above description, the polymer of the present invention is excellent in dry etching resistance and transparency, and the resist material using the polymer of the present invention is excellent in resolution and substrate adhesion. Accordingly, it is possible to form a fine pattern required for manufacturing a semiconductor device.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuo Hasegawa 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (56) References JP-A-8-333304 (JP, A) Tetrahedron Letters, No. 10, p. 723-726 (1976) Chemical Abstracts, 107: 236119 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07D 307/77 C07D 307/93 G03F 7/027 501 G03F 7/039 601 CAPLUS (STN ) REGISTRY (STN)

Claims (6)

(57) [Claims] 1. A (meth) acrylate derivative represented by the general formula (1). Embedded image (In the above formula, R ¹ and R ² represent a hydrogen atom or a methyl group.) 2. A polymer obtained by polymerizing (meth) acrylate derivatives according to claim 1 or copolymerizing the (meth) acrylate derivative according to claim 1 with another polymerizable compound. . 3. The polymer represented by the general formula (2):
The polymer according to claim 2, wherein the weight average molecular weight is 2,000 to 200,000. Embedded image (In the above formula, R ¹ , R ² , R ³ , and R ⁵ are a hydrogen atom or a methyl group, R ⁴ is a group capable of decomposing by an acid, and a bridged cyclic carbon having 7 to 13 carbon atoms having a group decomposing by an acid. R6 represents a hydrogen atom or a bridged cyclic hydrocarbon group having a carbon number of 7 to 13 having a carboxyl group;
2 represents a hydrocarbon group. x, y, z are x + y +
z is an arbitrary number satisfying 0, 0 <x ≦ 1, 0 ≦ y <1, and 0 ≦ z <1. ) 4. A photoresist composition comprising 70 to 99.8% by weight of at least one of the polymers according to claim 2 and 0.2 to 30% by weight of a photoacid generator which generates an acid upon exposure. Stuff. 5. A process comprising applying the photoresist composition according to claim 4 onto a substrate to be processed, exposing the substrate to light having a wavelength of 180 to 220 nm or less, performing a baking process, and performing a developing process. A pattern forming method, characterized in that: 6. The pattern forming method according to claim 5, wherein the exposure light is ArF excimer laser light.