JPH02161436A - Photoresist composition and its usage - Google Patents

Abstract

PURPOSE:To enable to form both positive and negative resist patterns by using a resist compsn. contg. a base resin contg. an specified acetal of poly(p- vinylphenol) residue and poly(p-vinylphenol) residue as recurrent units, a specified poly-halide, and a specified hydrogen donating agent. CONSTITUTION:A base resin contg. an acetal of poly(p-vinylphenol) residue expressed by the formula I and a poly(p-vinylphenol) residue expressed by the formula II as recurrent units, a photosensitizing agent consisting of at least one kind of polyhalide expressed by the formula III, IV or V, and a hydrogen donating agent comprising tri-n-aklylamine, etc., are incorporated into the photoresist compsn. In the formula I, R<1> is either one of tetrahydro pyranyl group or 1-methoxyethyl group, etc. In the formula III-V, X is Cl or Br; n is an integer 1-3. Thus, both negative and positive resist patterns having small light absorption coefft. in far ultraviolet region can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a photoresist composition used in the manufacture of semiconductor devices, etc., and a resist pattern forming technique using this composition. ~300(nm
) and a method of using the same.

(Prior Art) With the increasing integration and speed of semiconductor devices 1, the requirements for the microfabrication technology used in the manufacturing of semiconductor devices are becoming increasingly strict. Among these microfabrication technologies, In particular, since resist process technology is a fundamental technology for proceeding with the manufacture of semiconductor devices, a technology that can obtain a desired resist pattern is desired.

There have been various types of photoresist compositions (hereinafter sometimes simply referred to as compositions) for pattern formation used in such resist processes, but novolak-based ones have been used because of their high resolution. Positive resists have been often used, which are composed of a resin as a base resin and a naphthoquinone cyacyto-based photosensitizer added thereto. According to this positive resist, the 9 wires of an ultra-high pressure mercury lamp (
It is possible to form a resist pattern with a resolution line width of about 0.8 (μm) using a reduction projection type exposure apparatus using a wavelength of 436 nm.

By the way, if the resolution linewidth is day, the numerical aperture of the reduction projection lens provided in the exposure device is NA, and the wavelength of the light used for exposure is λ, then this resolution linewidth R is expressed as λ/NA (
k is a constant determined by the process). Therefore, if the resolution is to be increased significantly in the future, it is necessary to decrease λ or increase NA.

However, increasing the numerical aperture has the disadvantage that the depth of focus becomes shallower. Also, set the depth of focus to the desired value,
In order to ensure a constant field size, it is necessary to use a lens with a large diameter, but it is often technically difficult to create such a large lens, so it is necessary to increase the numerical aperture. is not a good thing.

On the other hand, reducing λ, that is, shortening the wavelength of the light source, is currently being done by using an Xe-89 lamp, and the rF excimer laser (wavelength 248 (nm)
) ) is also becoming possible. Therefore, by using a light source that generates such deep ultraviolet rays and a composition that is sensitive to these light sources, it becomes possible to form a roughly fine resist pattern.

The following are known as such conventional compositions for far ultraviolet rays.

First, FMP2400JI (manufactured by Silabray Co., Ltd.) was used as a composition capable of forming a positive resist pattern.

Product name) is known. This positive composition is composed of a combination of a cresol novolak resin and a quinone diazide photosensitizer. This F MP2400. ! l
The light absorption coefficient at 250 (nm) is 3 (un
-') was large.

On the other hand, as a negative composition, for example, the literature: "IEE
E TRANSACTIONS ON ELECTRO
N DEVICES (IEE Transaction On Electron Devices)” (E
O-28(II) Nov.

(+981) P, +306), poly(
A combination of p-vinylphenol) and 3,3'-diazidiphenylsulfone is known.

The light absorption coefficient of this negative type composition at 250 (nm) is about 4 (u, rrr'), which is similar to that of the Xe-89 lamp and cold mirror CM290! It is said that when contact exposure is carried out using the same method, a line pattern with a width of 0.4 (un) and an interval of 761.2 (lum) can be resolved.

(Problem to be Solved by the Invention) However, the conventional photoresist composition for far ultraviolet rays described above has a light absorption coefficient of around 250 (nm), although there is some variation depending on the physical properties of the base resin. It is large, approximately 2 (urrr') or more.

Therefore, in the prior art, when forming a resist pattern in a submicron region, it is difficult to form a pattern with an aspect ratio of 2 or more, for example.

To explain this point in detail, first, in the case of a conventional positive composition, patterning is achieved by removing the exposed portion of the resist film.

For this reason, if the light absorption coefficient of the composition or the compound generated after exposure is large, the light will not reach the vicinity of the substrate to be processed, and a residual film may be formed in the exposed area or the cross-sectional shape of the resist pattern may become trapezoidal. exhibits.

Furthermore, in the case of a conventional negative composition, patterning is achieved by leaving exposed areas of the resist film. For this reason, as with positive-working compositions, light does not reach the vicinity of the substrate to be processed, resulting in pattern sag in exposed areas and inverted trapezoidal cross-sections of the resist pattern.

In addition to this, in the manufacturing process of semiconductor devices,
A positive type resist process or a negative type resist process is used depending on the design of a semiconductor device. However, in the conventionally known photoresist compositions for far ultraviolet rays, the pace tree is designed depending on the pattern forming method such as positive type or negative type, and the composition is a material exclusively for the pattern forming method. As described above, it is difficult to develop a composition that can be used to form both a positive resist pattern and a negative resist pattern. It is necessary to prepare a device to be used before exposure for each of the above-mentioned formation methods, making it difficult to reduce costs.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a photoresist composition that has a small light absorption coefficient in the deep ultraviolet region and is capable of forming both positive and negative resist patterns; The object of the present invention is to provide a suitable method of using the composition.

(Means for Solving the Problem) In order to achieve this object, the photoresist composition according to the first aspect of this application provides a poly(p-vinylphenol) residue represented by the following general formula (I). acetal of the group (wherein, R+ is a tetrahydrodoranyl group, 1-(
methoxyethyl) group, 1-(ethoxyethyl) group or tetrahydrofuranyl group. ) and a poly(p-vinylphenol) residue H represented by the following structural formula (11) as a repeating unit, and a base resin containing the following general formulas (I [I) to (V)]. S expressed as either
-triazine derivative (III) (IV) (V) (However, in these formulas, × represents chlorine or 1 represents bromine,
R2 preferably represents an alkyl group having about 1 to 3 carbon atoms. ) Or, polyhaloacetamides X represented by the following general formula (■), CH3~, CONH2... (Vl) (however,
In the formula, X represents chlorine or bromine, and n represents an integer of 1-3. ) Or, polyhaloacetic acids X represented by the following general formula (■), CH3-C0OH'' (■) (However, in the formula, × represents chlorine or bromine, and n is 1 to
Indicates an integer of 3. ) A photosensitizer made of one or more polyhalogen compounds; and a hydrogen donor made of tri-n-alkylamines or tri(ω-hydroxy)amines. Toshide is here.

In carrying out this first invention, the content of N in the photosensitizer in the above-mentioned photoresist composition is 2 (mol%) or more and 20 (
mo1%) or less, and the content of the hydrogen donor described above in the photoresist composition is 1it0.5 (mol%)
It is preferable that the amount is less than 2 (mol%).

Among these, 2 (m
mol%) is the amount necessary to maintain the sensitivity of the photo-17ist composition, and the upper limit of the content is 20(mol%).
) is the amount necessary to maintain adhesion between the resist pattern and the substrate to be processed.

In addition, the lower limit of the content of the hydrogen donor mentioned above is 0, 5
(mo1%) is the amount necessary to supply hydrogen halide to the base resin, which will be explained in detail later, and the upper limit of the content, less than 2 (mo2%), refers to the amount of hydrogen donating agent. This is a condition for making it less than the lower limit of the photosensitive agent mentioned above and making it possible to form a negative resist pattern.

Next, in order to achieve the above-mentioned object, according to the method of using the photoresist composition according to the second invention of this application, the photoresist composition according to the first invention is applied to the surface of the substrate to be processed to form a resist. After forming the film, the equivalent weight N of halogen radicals generated from the photosensitive agent made of the polyhalogen compound described above and the equivalent weight N of the hydrogen donor described above are determined to be N
* Exposure to deep ultraviolet rays through a photomask under low dose conditions satisfying <N H to form a low dose exposed area and an unexposed area on the above resist film, and then develop this low dose exposed area with alkaline development. It is characterized by forming a positive resist pattern by removing it with a liquid.

Further, according to the method of using the photoresist composition according to the third invention of this application, after coating the photoresist composition according to the first invention on the surface of the substrate to be processed to form a resist film, the above-mentioned Exposure to deep ultraviolet rays through a photomask was performed under high dose conditions where the equivalent of halogen radicals generated from a photosensitizer made of a halogen compound x p = and the equivalent of the hydrogen donor described above, N, satisfies NR>NH. The resist film is characterized by forming high-dose exposed areas and unexposed areas, and removing the unexposed areas with an organic developer to form a negative resist pattern.

Furthermore, according to the method of using the photoresist composition according to the fourth invention of this application, after applying the photoresist composition according to the first invention to the surface of the substrate to be processed to form a resist film, The above-mentioned resist is exposed to deep ultraviolet light through a photomask under high-dose conditions where the equivalent NR of halogen radicals generated from a photosensitizer made of a halogen compound and the above-mentioned IN of the hydrogen donor satisfy NR>NH. A high dose exposed area and an unexposed area are formed in the film, and the high dose exposed area and the unexposed area are
The entire surface of the unexposed area is exposed to deep ultraviolet rays under low dose conditions where the above-mentioned equivalent of halogen radicals generated from the photosensitizer N N and the above-mentioned equivalent of hydrogen donor A satisfy N p = < NH. It is characterized by performing exposure to form a low-dose exposed area, and removing this low-dose exposed area with an alkaline developer to form a negative resist pattern.

(Function) First of all, according to the photoresist composition of the first invention according to this application, the acetal of the poly(p-vinylphenol) residue represented by the general formula (I) and the structural formula (II) Poly(p-vinylphenol) represented by
a base resin containing the residue as a repeating unit, one of the polyhalogen compounds represented by the above-mentioned general formulas (III) to (VII), and a hydrogen donor of any of the above-mentioned tertiary amines. The structure includes:

Among these, the acetal of the Bois (p-vinylphenol) residue contained in the base resin has a series of functional groups represented by the above-mentioned 81 at a part of the phenolic hydroxyl group position of the poly(p-vinylphenol). The light absorption coefficient in the far ultraviolet region is as small as about 0.25 (um-').

In addition, a series of polyhalogen compounds contained as photosensitizers also have a light absorption coefficient of 0.5 (urrr') or less in the deep ultraviolet region, and are composed of the base resin, polyhalogen compound, and hydrogen donor described above. The photoresist composition can achieve a small light absorption coefficient of 1 (un-') or less for the entire composition.

The base resin contained in the photoresist composition according to the first invention is made of poly(p-vinylphenol) by the competitive reaction of the above-mentioned photosensitizer and hydrogen donor.
Increased polarity due to ether bond cleavage of the acetal of the residue; Increased molecular weight due to dissociation of hydrogen at the benzylic position of poly(p-vinylphenol) residues (including those generated by the above-mentioned ether bond cleavage). It can selectively exert its action.

The formation of a resist pattern using the functions of the composition according to the first invention is thought to be based on the following mechanism.

First, polyhalogen compounds (inclusively represented as Rs-X), which are photosensitizers, generate halogen radicals (represented as X') when irradiated with far ultraviolet rays.

h ν Day5-X -1→day, "+X" The halogen radicals generated in this way have high reactivity with hydrogen, and the hydrogen at the benzylic position of the base resin and the hydrogen present at the end of the hydrogen donor It has reactivity with both. Therefore, by containing a hydrogen donor that is more reactive than the above-mentioned hydrogen at the benzylic position and controlling the generation t of halogen radicals by the dose of far ultraviolet irradiation, the above two functions can be selectively achieved. (You can take this.

To explain in detail, first, under low dose conditions, halogen radicals generated by far ultraviolet irradiation are
is less than the equivalent weight N of the hydrogen donor contained in the photoresist composition.

Therefore, the generated halogen radicals are consumed by abstracting hydrogen from the hydrogen donor, resulting in the production of hydrogen halide. Therefore, this hydrogen halide acts as an acidic catalyst to regenerate the phenolic hydroxyl groups of the base resin, achieving only the function (2) mentioned above.

(However, in this formula, R1 as a product forms an unsaturated bond within the molecule.) In addition, JINII, a halogen radical generated by far ultraviolet irradiation under high dose conditions, The amount is greater than the equivalent amount N of the hydrogen donor contained in the composition. As a result, the generated halogen radicals extract hydrogen from the hydrogen donor and completely consume the donor, leaving an excess of halogen radicals. Therefore, the above-mentioned regeneration reaction of phenolic hydroxyl groups by hydrogen halide progresses to achieve the function (2), and the excess halogen radicals also cause polymerization of the base resin (abstraction of hydrogen at the benzyl position). functions are achieved.

The method of using the photoresist composition according to the second to fourth inventions of this application is to form a resist pattern by selecting the above-mentioned high dose condition and low dose condition.

(Examples) Examples of the invention according to this application will be described in detail below. In the following examples, specific conditions will be illustrated and explained in order to facilitate understanding of the present invention, but it should be understood that the present invention is not limited only to these examples.

Furthermore, although the sources of the chemicals used in the following examples may be omitted in some cases, they are all chemically sufficiently pure and readily available.

Otsuki Riseyu.

Synthesis of base resin> First, as an example of the synthesis procedure for the base resin used in this example, a tetrahydropyranyl group was added to a poly(p-vinylphenol) residue derived from poly(p-vinylphenol). A case in which an acetal unit bonded to an ether is included will be explained in detail.

First, as a starting material, poly(p-vinylphenol)
(Weight average molecule!i: 16.000, and weight average molecular weight/number average molecular weight = 1.2) 12.0
(9) and 2,3-dihydrobilane 8.4 (9) were weighed, and tetrahydrofuran (hereinafter, THF) was used as a solvent.
It is sometimes called. )+00(mβ). After that, this mixed solution was cooled to 0 (°C) in a water bath, and p-toluenesulfonic acid monohydrate was added to the solution.
．． 1(c+)! Add with stirring and stir roughly for 30 minutes.

By the addition of the hydrate of p-toluenesulfonic acid, the temperature of the reaction mixture rose to about +5 ('C).

Subsequently, triethylamine 1 (rn
By adding β), p-toluenesulfonic acid is neutralized and the reaction due to the addition of the compound is stopped.

Next, a portion of the THF added to this reaction mixture is distilled off under reduced pressure according to a conventional method, so that the volume of the mixture is about 50 (mβ).

Thereafter, the above-mentioned reaction mixture of about 50 (mβ) was gradually added to ice-cooled methanol 1 (β) over about 15 minutes, and the formed precipitate was collected by filtration.

The precipitate thus obtained was dissolved in 50 (ml) of THE, and in the same manner as described above, the precipitate was dissolved in cold methanol 1 (β).
) and reprecipitate, and then filtered.

After washing the precipitate described above by repeating this reprecipitation operation four times in total, the precipitate obtained as a final acid product was vacuum-dried overnight, and the base resin according to this example was 13.0 (9) was obtained.

<Measurement of introduction rate of tetrahydropyranyl group into poly(p-vinylphenol)> Next, the introduction rate of tetrahydropyranyl group in the base resin obtained by the above-mentioned synthesis procedure was measured.

This introduction rate was measured by ') I-NMR spectroscopy according to a conventional method. That is, the integrated value of the spectrum derived from hydrogen in the benzene ring obtained when the 6 value is 7.8-8.5, and the spectrum derived from the hydrogen at the acetal root of the tetrahydrobilane ring obtained when the 6 value is 5.1. The above-mentioned introduction rate was determined by comparison with the integrated value.

As a result, the introduction rate of tetrahydropyranyl groups into the base resin synthesized in Example 1 was 90 (%).

Therefore, the base resin synthesized in Example 1 consists of acetal of poly(p-vinylphenol) residues shown by the following structural formula and poly(p-vinylphenol) shown by the above-mentioned structural formula (II). It was found that the compound has -C as a repeating unit.

Measurement of light absorption coefficient of base resin> Next, the above-mentioned base resin (hereinafter sometimes simply referred to as THP ether resin) was wetted with 2-methoxyethyl acetate, spin-coated onto a quartz substrate, and dried. A film was prepared.

When the absorption of the thus obtained film in the far ultraviolet region was measured, the maximum absorption wavelength λff1aX was 281 (nm), and the light absorption coefficient at 250 (nm) was 0.27 (Ll m-'). there were.

Similar measurements were also conducted on poly(p-vinylphenol), which is the starting material for synthesizing this THP ether tree. As a result, the light absorption coefficient at 250 (nm) was equivalent to that of the base resin according to the above-mentioned example, and no increase in the coefficient was observed due to the introduction of the tetrahydropyranyl group.

<Preparation of Resist Solution> Next, a resist solution for use in actual resist pattern formation, prepared by adding a solvent to the photoresist composition containing the THP ether resin obtained by the above-described synthesis procedure, will be described.

In this example, the above-mentioned general formula (III) was used as the photosensitizer.
Using tris(trichloromethyl)-8-triazine, which is classified as
Use triethanolamine, which is classified as an amine.

The compositions of this resist solution are as follows.

(i) Heath resin THP ether tree Fe 1.2 (9X94 (mo1
%) equivalent) (11) Photosensitizer tonos(trichloromethyl) ~5-)-Tuazine 0,
(equivalent to 22 (9) C5 (mol%)) (iii) Hydrogen donor triethanolamine 0.015 (equivalent to 9X 1 (mol%)) (iv) Solvent 2-methoxyethyl acetate 5 (mβ) In addition, each of these substances After mixing, the mixture was filtered using a membrane filter having a pore size of 0.2 (μm) to obtain a resist solution.

Such a resist solution was spin-coated onto a quartz substrate, dried, a film was prepared, and the absorption in the far ultraviolet region was measured in the same manner as described above. The light absorption coefficient at 250 (nm) was 0.6 (um). -').

Examples according to the second to fourth inventions in which resist patterns were actually formed using the resist solution obtained in Example 1 described above will be described below with reference to the drawings.

[Dog] 1.2 First, Example 2 according to the second invention of this application will be explained.

FIGS. 1A to 1C are schematic cross-sectional views of a substrate for each resist pattern formation step to explain the embodiment.

First, hexamethyldisilazane is spin-coated on the surface of the substrate 11 to be processed, which is a silicon wafer (diameter 3 inches (1 inch is 2.54 cm)), and pretreatment is performed.

Subsequently, the above-mentioned resist solution was spin-coated on the surface of the substrate 11 to be processed, and heated at 80 ('C) using a hot plate.
Soft baking is performed for 1 minute at a temperature of .mu.m to obtain a resist film 13 having a thickness of .mu.m as shown in FIG. 1(A).

In addition, the temperature of the above-mentioned soft baking is preferably 70 ('C) or higher in order to evaporate the solvent 2-methoxyethyl acetate.5 In order to avoid thermal decomposition of the composition, It is preferable that the temperature is 110 ("C) or less.

Next, using an Xs-Hg lamp (not shown) (a PLA501 aligner manufactured by Canon Inc. equipped with a 0M250 cold mirror) and a photomask 15 made of quartz, a series of Contact exposure is performed under low dose conditions as indicated by arrow a, and in this way, low dose exposed portions 13a and unexposed portions 13b are formed.

Subsequently, the exposed substrate 11 was placed in a developer prepared by diluting an alkaline developer rMF312 J (2 product names manufactured by Silaplay Co., Ltd.) to 4 times its volume with pure water.
By dipping for a second, the low-dose exposed portion 13a described above is removed. Thereafter, the resist is rinsed with pure water and dried to obtain a positive resist pattern as shown in FIG. 1(C).

Here, the above-mentioned low dose conditions will be explained.

In this Example 2, when considering the above-mentioned low dose condition, the dose amount % 5 (m
The resist pattern was obtained by increasing the dose amount by 5 (mJ/cm2) in increments of 5 (mJ/cm2) up to a maximum of 40 (mJ/cm2) and making multiple samples by varying the dose amount. The state of formation was observed using an optical microscope.

As a result, in the sample where the dose jl was 15 (mJ/cm2), the resist film corresponding to the low-dose exposed area 13a was completely removed, and the dose amount @ 20 (mJ/cm2) ~
40 (mJ/am2), the lines and spaces are formed with a dimension of 1=1.

Roughly, the dose N @ 20 (mJ/cm2) was set, and multiple samples were formed according to each mask and width using multiple photomasks with different line and spaces. A sample was prepared and observed. As a result, a resist pattern having a minimum line and space of 0.4 (um) or a taper angle of approximately 80° was formed.

Also, low dose condition % 15-40 (mJ/cm2)
When resist pattern formation is performed within the range of
The remaining film rate measured using a film thickness meter is practically 100 (%)
Met.

From the results of Example 2 described above, when the photoresist composition according to the first invention of this application is used and the resist solution described as Example 1 is used, low dose conditions for forming a positive resist pattern are obtained. is 15 (mJ/cm
2) It can be understood that it is preferably 20 (mJ/cm2) or more (the upper limit will be explained in detail later).

Furthermore, in the low-dose exposed area 13a that is removed in the above-described development process, only the ether bond is broken due to the mechanism already explained, so there is a difference in polarity between the low-dose exposed area 13a and the unexposed area +3b where the bond is maintained. It is considered that this resulted in the formation of a positive resist pattern.

Next, a third embodiment of the third invention of this application will be explained.

2(A) to 2(C) are schematic cross-sectional views of the substrate similar to FIGS. 1(A) to 1(C) for explaining the third embodiment.

First, under the same conditions as in Example 2, pretreatment of the substrate 11 to be processed, spin coating of the resist solution described above, and soft baking are performed to form a resist film 13 with a film thickness of 1 (um) (see Fig. 2). (A)).

Next, using the aforementioned Xe-89 lamp and a photomask 15 made of quartz, a series of arrows b in FIG.
Blink exposure is performed under high dose conditions as shown with v. In this way, the high dose exposed area 17 and the unexposed area +3
b is formed.

Subsequently, in this Example 2, the processed substrate +17 after exposure was added to an isoamyl acetate developer as an example of an organic developer.
a) By dipping for 60 seconds, the above-mentioned unexposed area +3bt is removed. Thereafter, the resist is rinsed with cyclohexane for 20 seconds, and then dried to obtain a negative resist pattern as shown in FIG. 2(C).

Here, the above-mentioned high dose amount conditions will be explained.

In this Example 3, when considering the above-mentioned high dose conditions, the dose related to far ultraviolet irradiation was set at 20 (mJ).
/cm2) by 20 (mJ/cm2),
A plurality of samples were prepared by varying the dose amount up to 160 (mJ/cm2), and the formation state of the resist pattern obtained under each dose amount condition was observed using an optical microscope.

As a result, the dose was reduced to 100-160 (mJ/cm2).
For each sample, the line and space ratio was 1:1.
It was formed with the dimensions of

Roughly, the dose was set to 100 (mJ/cm2), and after forming multiple samples according to each mask using multiple photomasks with different line and spaces, each sample was prepared for scanning electron microscopy. Fabricated and observed. As a result, the minimum 0.4 (um
) was formed into a rectangular shape with a taper angle of 90°.

In addition, when the film thickness of the sample formed under each dose amount condition was measured using a film thickness meter as described above, it was found to be 80 (mJ/c
When the resist pattern was formed under a high dose condition of m2) or more, preferably 10100 (/cm2) or more, the residual film rate was substantially 100 (%).

From the results of Example 3 described above, when the resist solution described in Example 1 is used, the high dose condition for forming a negative resist pattern is 80 (mJ/cm2).
) The above can be understood.

In addition, the high-dose exposed area 17 removed in the above-mentioned development process is separated from the unexposed area +3b where the molecular weight does not increase, because the molecular weight increases after ether bond cleavage due to the mechanism already explained. It is thought that the formation of a negative resist pattern was achieved due to a difference in solubility in the organic developer.

Next, regarding the fourth embodiment of the fourth invention of this application, the first
This will be explained with reference to FIGS. 3A to 3D, which are schematic cross-sections of the substrate similar to those in FIGS.

In Example 4 as well, under the same conditions as Example 2 and Example 3, pretreatment of the substrate 11 to be processed, spin coating of the resist solution having the above-mentioned composition, and soft baking were performed, and the film thickness was 1 (μ
A resist film 13 (m) is formed (FIG. 3(A)).

Next, using the X5-89 Lasip described above and a photomask 15 made of quartz, contact exposure is performed under the same high dose conditions as in Example 3. The exposed area +3b is formed (Fig. 3(B)
).

Subsequently, in this Example 4T, the entire surface is exposed under the same low dose conditions as in Example 2 without using a photomask, and a low dose exposed portion 13a is formed (see FIG. 3).
C)).

Thereafter, development and rinsing are performed using the above-mentioned alkaline developer under the same conditions as in the example, to form a negative resist pattern as shown in FIG. 3CD).

Here, the above-mentioned high dose amount condition and low dose amount condition will be explained.

In this Example 4, the results in Example 2 and Example 3 were used as reference when examining the above-mentioned high dose condition and low dose 1 condition. That is, the high dose condition using a photomask is 80 (mJ/c) determined in Example 3.
m2), and a value of 20 (mJ/cm2) among the low dose conditions determined from Example 2 was used for the entire surface exposure.

By forming a resist pattern using these two conditions, high molecular weight does not increase in the high dose exposed area 17 that is to be left, and ether bond cleavage occurs in the low dose exposed area 13a that is desired to be removed. cause only. In this way, a negative resist pattern can be formed due to the difference in solubility in an alkaline developer.

In addition, the above-mentioned 2f! By combining similar dose conditions,
After forming a plurality of samples according to each mask using a plurality of photomasks with different line and spaces, each sample was prepared for a scanning electron microscope and observed. Similarly, a resist pattern with a minimum line and space of 0.4 (um) is 9
It was formed into a rectangular shape with a taper angle of 0''.

From the exposure conditions obtained in Examples 2 to 4, it was found that the photoresist composition of the combination described in Example 1T had a low Only the ether bond can be cut by adjusting the dosage condition, and the preferred dose is 100
(mJ/cm2) or more, the high molecular weight of the base resin described above can be achieved. In this way, it is possible to take a sufficient difference in the exposure amount between the positive pattern and the negative pattern.
Both of these resist pattern formations can be easily selected without causing negative reversal.

Examples using other photoresist compositions will be explained below.

K dish history 5 In this example 5, tris(trichloromethyl)-s
- Instead of triazine, 0.163 (m9) (corresponding to about 9.5 (mol%)) of trichloroacetamide classified into the general formula (Vl) mentioned above was used as a photosensitizer, and the other compositions were not changed. A resist solution was prepared identical to the resist solution described in Example 1.

250(n) of the photoresist composition according to this Example 5
The light absorption coefficient at m) was 0.7 (um-').

In addition, as an organic developer for forming a negative resist pattern, one in which the volume ratio of inamyl acetate and 2-methoxyethyl acetate was 9=1 was used, and development was performed for 50 seconds, and development was performed for 30 seconds using cyclohexane. A resist pattern was formed through three types of exposure and development processes using the same procedures and conditions as in Examples 2 to 4, except that rinsing was performed.

To give an example of the results, the high dose condition was set to 240 (m
J/cm2), and when forming a negative resist pattern in the same manner as in Example 4 under a low dose condition of roughly 80 (mJ/cm2), it is possible to form a minimum line and space of 0.5 (un). The cross-sectional shape was rectangular as described above.

Comparison In this comparative example, the tris (tris 0
A resist solution according to a comparative example was prepared by using tribromoquinaldine 0.19 (mq) as a photosensitive agent instead of (methyl)-s-triazine and using the same composition as the resist solution described in Example 1. .

250 (nm) of the photoresist composition according to this comparative example.
) was 2.0 (um-').

When a resist pattern was formed using the resist solution according to the comparative example in the same manner as in the above-mentioned example,
Even if the dosage conditions were changed, a positive resist pattern could not be formed.

Although the embodiments of the invention according to this application have been described in detail above, it is clear that the invention is not limited only to the embodiments described above.

For example, when forming a positive resist pattern using the second invention of this application, by exposing it to light under high dose conditions after development, the low dose exposed area (see FIG. 1 (C) 9 ) can be expected to have a high molecular weight and to improve the heat resistance properties called "U-cure".

In addition, in the above-mentioned example, the weight average molecular weight is 16 as an example of the base resin constituting the photoresist composition.
The case where 90 (%) of tetrahydropyranyl groups were introduced into 1,000 poly(p-vinylphenol) was explained. However, the present invention is not limited thereto, and the above-mentioned weight average molecular weight may be easily available with a weight average molecular weight of about 1,000 to too, ooo, and instead of the tetrahydropyranyl group, a 1-(methoxyethyl) group, ]-(ethoxyethyl) group or tetrahydrofuranyl group may be introduced. The introduction rate of various groups constituting such ether bonds is preferably 60 (%) or more in order to enable formation of a positive pattern.

Further, in the above-mentioned embodiments, specific photosensitizers and hydrogen donor agents were exemplified and explained, but these materials and the numerical conditions related to the usage method using the materials are within the scope of the purpose of this invention. Obviously, any suitable modifications and variations in design may be made.

(Effects of the Invention) As is clear from the above explanation, the photoresist composition according to the present invention uses a combination of a base resin, a photosensitizer, and a hydrogen donor that have a small light absorption coefficient in the deep ultraviolet region. configured. Furthermore, the base resin contained in the composition of the present invention has the functions of both changing the polarity and increasing the molecular weight by controlling the dose t of deep ultraviolet irradiation.

Therefore, the invention of this application provides a photoresist composition that has a small light absorption coefficient in the deep ultraviolet region and is capable of forming both positive and negative resist patterns, and a photoresist composition that can be applied to the composition. Accordingly, it is possible to provide a suitable usage method, and in turn, it is possible to achieve various effects such as reduction in manufacturing costs of semiconductor devices and the like.

[Brief explanation of the drawing]

FIGS. 1(8) to (C) are explanatory diagrams showing schematic cross-sections of the substrate for each resist pattern forming process, mainly to explain Example 2 according to the second invention; FIG. 2(A) -(C) are explanatory diagrams shown in the same manner as FIG. 1 to mainly explain Example 3 according to the third invention, and FIGS. 3(A) to (D) are mainly examples according to the fourth invention. FIG. 4 is an explanatory diagram shown similarly to FIGS. 1 and 2 to explain 4. FIG. ) 1...Substrate to be processed, 13a...Low dose exposed area +3b...Unexposed area, 15...Photomask 17...High dose exposed area a...・Far ultraviolet b irradiated in the low-dose exposed area...
...Deep ultraviolet rays irradiated under high dose conditions. 2nd explanatory diagram of Example 3. 1st explanatory diagram of Embodiment 2. 3rd explanatory diagram of Embodiment 4.

Claims (5)

[Claims] (1) Acetal of poly(p-vinylphenol) residue represented by the general formula (I) below▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (However, in the formula, R^1 is tetrahydropyrani group, 1-
(methoxyethyl) group, 1-(ethoxyethyl) group, or tetrahydrofuranyl group. ) and a poly(p-vinylphenol) residue represented by the following structural formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) as a repeating unit, and a base resin containing the following general formula s- represented by any of (III) to (V)
Triazine derivative (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (V) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, in these formulas, X is Represents chlorine or bromine, R
^2 represents an alkyl group. ) Or polyhaloacetamides represented by the following general formula (VI) X_nCH_3_-_nCONH_2...(VI) (however,
In the formula, X represents chlorine or bromine, and n represents an integer of 1 to 3. ) Or polyhaloacetic acids represented by the following general formula (VII) X_nCH_3_-_nCOOH...(VII) (However, in the formula,
Indicates an integer of 3. ) A photosensitizer made of one or more polyhalogen compounds; and a hydrogen donor made of tri-n-alkylamines or tri(ω-hydroxy)amines. A photoresist composition. (2) The content of the photosensitizer in the photoresist composition according to claim 1 is set at 2 (mol%) or more to 20 (mol%).
%) or less, and the content of the hydrogen donor is 0.5(
1. A photoresist composition characterized by having a composition of at least 2 (mol%) and less than 2 (mol%). (3) After applying the photoresist composition according to claim 1 to the surface of a substrate to be processed to form a resist film, the equivalent amount N_R of halogen radicals generated from the photosensitizer and the equivalent amount N_H of the hydrogen donor are determined. is exposed to deep ultraviolet rays through a photomask under low-dose conditions satisfying N_R<N_H, forming low-dose exposed areas and unexposed areas in the resist film, and removing the low-dose exposed areas with an alkaline developer. A method of using a photoresist composition, the method comprising: forming a positive resist pattern. (4) After applying the photoresist composition according to claim 1 to the surface of a substrate to be processed to form a resist film, the equivalent amount N_R of halogen radicals generated from the photosensitizer and the equivalent amount N_H of the hydrogen donor are determined. is exposed to deep ultraviolet light through a photomask under high dose conditions satisfying N_R>N_H, forming high dose exposed areas and unexposed areas in the resist film, and removing the unexposed areas with an organic developer. 1. A method of using a photoresist composition, the method comprising: forming a negative resist pattern. (5) After applying the photoresist composition according to claim 1 to the surface of a substrate to be processed to form a resist film, the equivalent amount N_R of halogen radicals generated from the photosensitizer and the equivalent amount N_H of the hydrogen donor are determined. is exposed to deep ultraviolet light through a photomask under high dose conditions satisfying N_R>N_H to form a high dose exposed area and an unexposed area in the resist film, and further, the high dose exposed area and the unexposed area are formed in the resist film. The entire surface is exposed to deep ultraviolet rays at a low dose under a low dose condition where the equivalent amount N_R of halogen radicals generated from the photosensitizer in the unexposed area and the equivalent amount N_H of the hydrogen donating agent satisfy N_R<N_H. A method of using a photoresist composition, which comprises forming an exposed area and removing the low-dose exposed area with an alkaline developer to form a negative resist pattern.