JPH07201704A - Manufacture of fine pattern and manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a fine pattern manufacturing method which stably forms an excellent fine resist pattern by one time exposure on a base substrate that has at least two areas in different optical conditions and provide a manufacturing method of a semiconductor device which uses such fine pattern manufacture. CONSTITUTION:A highly absorbing film 32 provided with high optical absorption against the wavelength of exposure beams to be used in the photolithography process is formed on a base substrate 25, a reflection preventing film 34 is formed on the highly absorbing film 32, and a resist film 28 is formed on the reflection preventing film 34. The resist film 34 is processed to the prescribed pattern by the photolithography.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a fine pattern and a method of manufacturing a semiconductor device using this method.

[0002]

2. Description of the Related Art Currently, in the research and development of semiconductor integrated circuits, design rule devices in the sub-half micron region are being researched and developed. In the photolithography technology used in the development of these devices, currently, the most advanced stepper (reduction projection exposure machine) uses KrF excimer laser light (248 nm) as a light source,
A lens with a numerical aperture (NA) of about 0.50 is mounted (for example, Nikon NSR1505EX1, Canon FP
A4500). Using these steppers, research and development of design rule devices in the sub-half micron (0.5 μm or less) region are being researched.

A stepper uses light of a single wavelength as an exposure light source. It is widely known that a phenomenon called a standing wave effect occurs when exposure is performed with a single wavelength.
The cause of the standing wave is that optical interference of exposure light occurs in the resist film. That is, as shown in FIG. 1, the incident light P and the reflected light R from the interface between the resist PR and the substrate S cause interference in the film of the resist RR.

As a result, as shown in FIG. 2, the amount of light absorbed by the resist (vertical axis) changes depending on the resist film thickness (horizontal axis). In the present specification, the amount of light absorbed by the resist means the amount of light absorbed by the resist itself, excluding surface reflection, absorption at the substrate, and amount of light emitted from the resist. This absorbed light quantity is
It becomes the energy for photoreacting the resist.

FIG. 2 shows the results of investigating the change in absorbed light quantity depending on the film thickness of the resist film (XP8843) formed on the silicon substrate. KrF of λ = 248 nm was assumed as the exposure light. Further, the degree of change in the absorbed light amount differs depending on the type of the base substrate, as can be understood from the comparison between FIGS. 3 and 4. 2, 3, 4
In the above, as the resist, XP8843 (Chipley Co., Ltd.) is used.
i, W-Si. That is, the degree of change in the absorbed light amount is determined by the complex amplitude reflectance (R) in consideration of multiple interference determined by the optical constants (n, k) of the base (substrate) and the optical constants (n, k) of the resist. ((R) is a vector quantity having a real part and an imaginary part).

Further, in the actual device, as shown in FIG. 5, the surface of the substrate S always has unevenness. For example, a polysilicon film or the like having a predetermined pattern may be formed on the substrate S, and a convex portion In of polysilicon or the like is present. Therefore, when the resist PR is applied, the resist film thickness differs between the upper part and the lower part of the step.
That is, the resist film thickness d _PR2 on the convex portion In becomes smaller than the other resist film thickness d _PR1 .

As described above, the standing wave effect varies depending on the resist film thickness. Therefore, the influence of the standing wave effect also changes the amount of light absorbed by the resist. come. As a result, the size of the resist pattern obtained after exposure and development differs between the upper part and the lower part of the step.

When the stepper having the same wavelength and the same numerical aperture is used, the effect of the standing wave effect on the pattern size becomes more remarkable as the pattern becomes finer, and is common to all kinds of resists. It is a phenomenon.
The dimensional accuracy of the resist pattern in the photolithography process when manufacturing devices such as semiconductor devices is generally ±
5%. Although it is considered to be practical even if it is looser than ± 5% in total, the pattern accuracy at the time of resist exposure is kept within ± 5% in consideration of variations due to other factors such as focus. Is desired. In order to achieve the dimensional accuracy of ± 5%, it is essential to reduce the standing wave effect.

FIG. 6 shows the dimensional variation of the resist pattern (vertical axis) with respect to the variation of the amount of absorbed light in the resist film (horizontal axis). As is clear from FIG. 6, for example, 0.3
In order to manufacture a device with a rule of 5 μm, the fluctuation of the amount of light absorbed by the resist film is required to be in the range of 6% or less.

Further, when actually manufacturing a semiconductor device, one step is performed on a base substrate having a step structure and having a plurality of regions A and B having different reflectances as shown in FIG. It is required that a fine resist pattern can be favorably and stably formed by exposure. In FIG. 7, reference numeral 2 is a silicon substrate, reference numeral 4 is a polysilicon film, reference numeral 6 is a tungsten silicide film, reference numeral 8 is a silicon oxide film, reference numeral 10 is a resist film, and reference numeral 12 is a photomask. In the example shown in FIG. 7, an example of patterning the silicon oxide film 8 using the photomask 12 is shown.
The area A and the area B have different reflectances from the underlying substrate.

As shown in FIG. 8, when the reflectance from the base substrate is different, the amount of light absorbed by the resist film is naturally different. Even in such a situation, in order to form a fine resist pattern satisfactorily and stably with one exposure,
The fluctuation of the absorbed light amount of the resist film is required to be 6% or less in the above range even if there is a region where the reflectance from the underlying substrate differs on the film surface of the substrate.

[0012]

In order to meet the above-mentioned demands, the antireflection technique is now being actively studied in various fields. The present inventor has made earnest studies on a means of reducing the fluctuation of the absorbed light amount of the resist film to, for example, a range of 6% or less. As a result, a refractory metal silicide such as tungsten silicide, a metal such as Al—Si, and polysilicon SiC, SiO _x , S on top of silicon materials
An antireflection film such as i _x O _y N _z or Si _z N _{y is formed} ,
It has been found that the standing wave effect can be reduced by forming a resist film on it.

However, the materials of these antireflection films are determined in accordance with the substrate material to be antireflection. Of course, when actually manufacturing a device, it is necessary to form a mask pattern on a substrate that has a step structure and the reflectance differs depending on the location of the mask pattern within a single exposure amount range. There is. In this case, the amount of light absorbed by the resist film is different at the place of the mask pattern due to the difference in reflectance at the place and place, and as a result, the fluctuation of the amount of absorbed light at the resist film is kept within the range of 6% or less. I can't.

As a conventional technique for forming a good mask pattern on a base substrate having a step structure and having different reflectances at different places, a multi-layer resist method and further dividing a mask into a plurality of masks are available. That is, a method of forming a pattern by exposing a plurality of times is known.

However, regarding the multilayer resist method, due to the complexity of the process, and regarding the multiple exposure method,
Since the requirement for alignment accuracy becomes extremely strict, it is required in the manufacturing process of semiconductor devices.
It cannot be a method for forming a fine pattern.

Therefore, even on a base substrate having a step structure and a plurality of different highly reflective regions having different reflectances, a fine resist pattern can be satisfactorily and stably formed by one exposure. It is desired to establish an antireflection technique that can be used. The present invention has been made in view of the above circumstances, and finely and stably forms a fine resist pattern in a single exposure on a base substrate including at least two regions having mutually different optical conditions. An object of the present invention is to provide a method of manufacturing a fine pattern that can be performed and a method of manufacturing a semiconductor device using the method.

[0017]

In order to achieve the above-mentioned object, the method for producing a fine pattern according to the present invention is such that a light absorption for a wavelength of exposure light used in a photolithography process is performed on a base substrate. Of a highly absorbing film, a step of forming an antireflection film on the highly absorbing film, a step of forming a resist film on the antireflection film, and a step of forming the resist film by a photolithography method. And a step of processing into a pattern.

The wavelength of the exposure light used in the photolithography step is preferably in the range of 150 to 400 nm. It is preferable that the high absorption film is made of any one of a silicon-based material, a titanium-based material, a refractory metal, a refractory metal compound, and a refractory metal silicide. When the high absorption film is a silicon-based material, the thickness of the high absorption film is preferably 9.5 to 40 nm. When the high absorption film is a titanium-based material, the thickness of the high absorption film is preferably 15 to 120 nm. When the high absorption film is a high melting point metal compound or a high melting point metal silicide, the film thickness of the high absorption film is 15 to 1
It is preferably 20 nm.

The antireflection film has a refractive index (n) of 1.8.
It is preferably 2.6 or more and the extinction coefficient (k) is 1.8 or more and 2.6 or less, and a silicon-based film containing at least nitrogen having a film thickness of 20 to 150 nm is preferable.
In order to achieve the above object, the first method for manufacturing a semiconductor device according to the present invention includes a high-absorption film having a high light-absorbing property with respect to a wavelength of exposure light used in a photolithography process, on a film to be processed. A step of forming, a step of forming an antireflection film on the high absorption film, a step of forming a resist film on the antireflection film, and a step of processing the resist film into a predetermined pattern by photolithography. A step of etching the antireflection film and the high-absorption film into a predetermined pattern by using the resist film having the predetermined pattern as a mask; and, after removing the resist film, using the antireflection film and the high-absorption layer as a mask, And a step of etching the film to be processed.

In order to achieve the above object, the second method for manufacturing a semiconductor device according to the present invention has a high light absorptivity with respect to the wavelength of exposure light used in the photolithography process on the film to be processed, A step of forming a high absorption film made of any one of refractory metal, refractory metal compound and refractory metal silicide; step of forming an antireflection film on the high absorption film; A step of forming a resist film on the antireflection film, a step of processing the resist film into a predetermined pattern by a photolithography method, and a step of using the resist film having the predetermined pattern as a mask to form the antireflection film, the high absorption film and the processed film. A process of etching a film into a predetermined pattern to form a hole in a film to be processed, and a refractory metal or a refractory metal on the antireflection film so as to enter the hole. Of a compound and a refractory metal silicide, a step of forming a base film, a step of embedding a conductive plug layer in the hole in which the base film is formed, and thereafter. Etching the upper part of the base film other than the inside of the hole, the antireflection film, the high absorption film, and the conductive plug layer by the entire surface etchback method.

In the present invention, light of i-line (365 nm) or shorter wavelength, such as i-line, KrF, ArF, is used.
When a fine pattern is formed on a base substrate using an excimer laser as a light source, in order to form a fine resist pattern satisfactorily and stably with one exposure,
First, a high absorption film is formed on the base substrate. This high-absorption film is a film having a high light absorption property for the wavelength of the exposure light used in the photolithography process. By forming this film, the regions where the optical conditions are different (and both have relatively high reflection). It is possible to reduce the reflected light from the underlying substrate on which the area (1) is formed to 2% or less. By forming this high-absorption film on the base substrate, the reflected light reflected from the regions having different optical conditions is 2% or less, and the base substrate can be regarded as a single type of substrate.

The following means was used to determine the high-absorption film so that the reflected light reflected from the regions having different optical conditions with respect to the exposure light is 2% or less. (I) Energy for photoreacting the resist, considering areas where the optical conditions are different, as a single substrate and considering multiple interference of exposure light in the resist film with respect to each of the plurality of substrates. Determine the amount of light absorbed by the resist. The degree of absorbed light differs depending on the optical constants (n, k) of the respective substrates.

(II) For each of a plurality of substrates having different optical constants, assuming that there is a high absorption film (k> 0) on the substrate, the film thickness of the high absorption film is gradually increased. The amount of light absorbed by the resist film is increased in consideration of the multiple interference of the exposure light within the region and the resist film.

(III) As a result of fluctuation of the amount of light absorbed inside the resist film for each substrate, which is obtained by assuming that there is a high absorption film on a plurality of substrates having different optical constants obtained in (II) above. Then, the optical constant and the film thickness of the high absorption film are obtained so that the respective results are the same.

(IV) A film of an actual material having the conditions obtained in (III) above is used as the high absorption film in the present invention. When a high absorption film that can be used in the present invention was searched for using the means (I) to (IV), n = 0.
It has been found that silicon-based materials such as single crystal silicon, polycrystal silicon, amorphous silicon, and doped silicon having 5 to 7 and k = 1.5 to 3.5 are desirable. The thickness of such a silicon-based material high absorption film is 9.5 to 40 n.
It has been found preferable to use m.

Further, it has been found that a high melting point metal such as tungsten or titanium or a compound of a high melting point metal, particularly a titanium-based material such as titanium nitride or titanium oxynitride is desirable. Such a refractory metal or a compound of a refractory metal is n =
It has optical constants of 0.5 to 3.0 and k = 0.5 to 3.0. Further, it has been found that the thickness of the high absorption film made of the high melting point metal or the compound of the high melting point metal is preferably 15 to 120 nm.

It has also been found that a refractory metal silicide material such as tungsten silicide is desirable. This refractory metal silicide material is
It has optical constants of n = 0.5 to 4.5 and k = 1.5 to 3.5. Further, it has been found that it is preferable to use the high absorption film composed of the high melting point metal silicide with a film thickness of 8 to 30 nm.

By forming a high absorption film of such a material on a base substrate including at least two regions having mutually different optical conditions, the reflectance from the base substrate can be suppressed to 2% or less. Optically, it is possible to regard the base substrate as a single type of substrate.

In the present invention, on such a high absorption film,
An antireflection film is formed. The determination of the antireflection film was performed using the following means. (I) For the film thickness of a resist with a certain film thickness,
A contour line of the amount of light absorbed in the resist film when the optical condition (n, k) of the antireflection film is continuously changed (however, the film thickness of the antireflection film is fixed) is obtained.

(II) From the result of the contour line of the absorbed light amount inside the resist in the film thickness of each resist film obtained in the above (I), a common region where the difference in the absorbed light amount is minimized is found, and is defined by this common region. Optical condition
The optical condition (n, k) in the film thickness of the antireflection film determined in 1.

(III) By changing the film thickness of the antireflection film,
The above operations (I) and (II) are repeated to obtain the optical constants (n, k) under the respective optimum conditions for the respective thicknesses of the antireflection film. (IV) Find an antireflection film of an actual material having an optical constant of the optimum condition obtained in (III) above.

Next, referring to the drawings, the above-mentioned means (I) to determine the comprehensive conditions of the antireflection film used in the present invention.
(IV) will be described more specifically. The resist film thickness between the maximum value and the minimum value of the standing wave effect is given by λ / 4n when the refractive index of the resist is n _PR and the wavelength of the exposure light is λ (see FIG. 9).

Antireflection between the resist and the base substrate
The film ARL is processed and its thickness d _arl, Optical constant n
_arl, K_arlAnd One point in FIG. 9 (for example, when the standing wave effect is maximum)
The thickness d) of the antireflection film.
_arlFix n_arl, K_arlIf you change
The amount of light absorbed by the resist film at the point changes. This change
When the contour line of the absorbed light quantity is obtained,
As shown in 0.

With respect to other different resist film thicknesses d _PR , at least with respect to the film thickness at which the standing wave effect is maximized or minimized, four locations at λ / 8n _PR intervals are set.
11 to 13 corresponding to FIG. 10 are obtained by repeating the above (FIGS. 10 to 13 show an antireflection film thickness of 20 nm).
And the resist film thickness is 985 nm and 1000 n, respectively.
m, 1018 nm, 1035 nm are shown).
The above corresponds to the above means (I).

The common region in each of the graphs of FIGS. 10 to 13 shows a region where the amount of absorbed light in the resist film does not change even if the resist film thickness changes for a specific film thickness of the antireflection film. . That is, the common region is a region having the highest antireflection effect that minimizes the standing wave effect.
Therefore, we find such a common area. The common area can be found, for example, simply by superposing the figures (graphs) and taking the common area (of course, the common area may be searched by a computer). This corresponds to the above means (II).

Next, the thickness d of the antireflection film is continuously changed and the above is repeated. For example, if the operation is performed with d = 20 nm until the first step, d is changed and the above is repeated. As a result, the film thickness d _{arl of the} antireflection film that minimizes the standing wave effect,
The conditions of the optical constants n _arl and k _arl can be specified. This corresponds to the above means (III).

The kind of film satisfying the conditions (thickness, optical constant) to be satisfied by the antireflection film specified above is found by measuring the optical constant of each film type in the exposure light. This corresponds to means (IV). The above method can be applied in principle to all wavelengths and all underlying substrates.

When the antireflection film which can be preferably used in the method according to the present invention is examined by the means (I) to (IV), the Si _X O _y N _z film or the Si _X N _y film is particularly preferable. Proved to be suitable. That is, when the above material is used as the high absorption film, the antireflection film is an organic film or an inorganic film having optical constants of n = 1.8 to 2.6 and k = 0.1 to 0.8. Membrane, especially Si _X O _y N
It has been found preferable to use a _z film (which may contain hydrogen H) or a Si _x N _y film with a film thickness of 20 to 150 nm.

These Si _X O _y N _z films or Si _X N _y
The film can be easily formed by various CVD methods. For example, these films are parallel plate plasma CVD
Method, ECR plasma CVD method, or bias ECR
Using a plasma CVD method and a microwave, a silane-based gas and a gas containing oxygen and nitrogen (for example, Si
Film formation can be performed using a mixed gas of H ₄ + O ₂ + N ₂ ) or a mixed gas of a silane-based gas and a gas containing nitrogen (for example, SiH ₄ + N ₂ O). Also, at that time,
Argon Ar gas or the like can be used as the buffer gas.

For example, as shown in FIG. 14, the Si _X O _y N _z film has an optical constant (n, k) of the film obtained depending on the film forming conditions, particularly the flow rate ratio of the silane-based gas. , N can be freely changed in the range of 1.5 to 2.7 and k is in the range of 0.1 to 0.8, so that the optical constants required as an antireflection film for a particular underlying substrate can be An antireflection film having a value can be easily made.

Further, these Si _X O _y N _z films or Si
_{The XNy} film uses CF ₄ and CHF as a mask for the resist.
It can be easily etched by RIE in which ₃ , C ₂ F ₆ , C ₄ F ₈ , SF ₆ , S ₂ F ₂ , and NF ₃ gas is used as an etchant and Ar is added to increase the ionicity. The RIE is 10 to 1 under a pressure of about 2 Pa.
It is preferable to apply a power of about 00W. The flow rate of the gas during RIE is not particularly limited, but is 5
It is preferably ˜70 SCCM.

Further, after the pattern is transferred to the underlying substrate by using the pattern-transferred high-absorbency film as a mask, the silicon-based, high-melting-point metal-based, and high-melting-point are formed by an etch back method using a fluorine-based gas. The metal compound-based or refractory metal silicide-based highly absorbent film can be easily removed.

In the method of manufacturing a fine pattern according to the present invention described above, the i-line (365n) is formed even on a base substrate having a plurality of regions having steps and different optical conditions.
m) shorter wavelength light, eg i-line, KrF, ArF
By using an excimer laser as a light source, a fine resist pattern can be formed satisfactorily and stably by a single exposure.

The method for producing a fine pattern according to the present invention is
In particular, it can be suitably used for a method of manufacturing a semiconductor device having a fine pattern.

[0045]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to the following examples and can be variously modified within the scope of the present invention. Example 1 In this example, when the present invention is used to manufacture a semiconductor using light having a wavelength shorter than that of i-line (365 nm), for example, i-line, KrF, ArF excimer lithography, a plurality of high reflectances having different reflectances are used. In a semiconductor manufacturing process in which a fine mask pattern is transferred onto one base substrate having a reflective layer region, polycrystalline silicon, amorphous silicon, doped polysilicon, etc. are used as a high absorption film formed on the entire surface of the base substrate. This is an example using the above silicon-based material.

In the semiconductor manufacturing method of this embodiment, first, as shown in FIG. 15, on a semiconductor substrate 20 made of, for example, a silicon wafer, a gate insulating layer is interposed,
Polysilicon layer 22 and tungsten silicide 24
Forming a polycide-structured gate electrode. A transparent insulating film 26 such as a silicon oxide film is formed thereon.
In the transparent insulating film 26, a region A located above the tungsten silicide 24 and a region B located above the impurity diffusion layer formed on the surface of the semiconductor substrate 20 are exposed using a photomask 30. At this time, the base substrate 25 (the semiconductor substrate 2 on which the polysilicon film 22, the tungsten silicide film 24, and the transparent insulating film 26 are formed)
The optical conditions of 0) are different.

Therefore, in this embodiment, the high absorption film 32 is first formed on the entire surface of the transparent insulating film 26. In this embodiment, the high absorption film 32 is made of a silicon material such as polysilicon, amorphous silicon, or doped silicon. i-line (365 nm), KrF (248 nm), Ar
Polycrystalline silicon (Poly-) at F (193 nm)
The optical constants (refractive index n) and absorption coefficient α (1 / nm) of Si) and amorphous silicon (α-Si) are as shown in Table 1 below.

[0048]

[Table 1]

The transmittance T of the film having the thickness d is the incident light quantity I.₀ ,
Let the amount of transmitted light be I, the wavelength be λ, and the absorption coefficient of the film be α
(= 4πk / λ), T (= I₀ / I) = exp (-αd). You
That is, the transmittance T increases as the absorption coefficient increases
Becomes thicker and becomes smaller, 1 / e² The transmittance is 13.
It will be about 5%. Incident light is reflected at the interface between the film and the underlying film
If the ratio is R (= 10 to 80%), I × R light is transmitted to the film.
Is reflected. Therefore, a reflection that returns in one reflection
Assuming that the amount of incident light is 1, the light component is 0.135 (= 1 /
e²) × (0.1-0.8) (= R) × 0.135 (=
1 / e ²) = 0.0018 to 0.014
It That is, 1 / e² A film that attenuates light to some extent
By using it, the reflected light can no longer be ignored.
It will be Le.

Therefore, if a high-absorption film satisfying such conditions is formed on the entire surface of the base substrate, the same substrate can be obtained on the base substrate having a plurality of high-reflection layers having different reflectances. Is equivalent to a single substrate having only the reflectance of. When using a silicon-based material such as polycrystalline silicon, amorphous silicon, or doped polysilicon as the high-absorption film, from the above Table 1, in order to satisfy αd ≧ 2, d = 9.5-40 nm It can be seen that the above film thickness can be used.

FIG. 16 shows a standing wave effect when a polysilicon film having a film thickness of 40 nm is formed on a silicon substrate and a resist is applied on the film. As a resist, XP8
843 was used. The resist n _PR and k _PR were 1.802 and 0.0107, respectively. The n _poly and k _poly of the polysilicon film were 1.68 and 3.27, respectively. N _sub and k of the semiconductor substrate
_{The sub} was 1.572 and 3.583, respectively. KrF having a wavelength λ of 248 nm was used as the exposure light.

In FIG. 17, on the tungsten silicide,
A standing wave effect is also shown when a polysilicon film having a film thickness of 40 nm is formed and a resist is applied on the film. XP8843 was used as the resist. The resist n _PR and k _PR were 1.802 and 0.0107, respectively. The n _poly and k _poly of the polysilicon film were 1.68 and 3.27, respectively. The n _WSi and k _WSi of the tungsten silicide were 1.96 and 2.69, respectively. The exposure light has a wavelength λ of 2
48 nm KrF was used.

In both figures, the horizontal axis shows the resist film thickness, and the vertical axis shows the amount of light absorbed by the resist, which is the component that actually exposes the resist. Comparing FIG. 16 and FIG. 17, the same result is obtained. That is, even on a base substrate having a plurality of highly reflective layer regions having different reflectances, a silicon-based material such as polycrystalline silicon, amorphous silicon, or doped polysilicon having a film thickness of 9.5 to 40 nm is used as the base substrate. By forming a film on the entire surface, the underlying substrate becomes substantially equivalent to a substrate having only the same reflection.

Therefore, as shown in FIG. 15, by providing the high absorption layer 32 of the present embodiment on the entire surface of the base substrate 25 on which the regions A and B having different optical conditions are formed, the base substrate 25 is formed. Has been proved to be able to be treated optically as if it were a single substrate.

On the surface of the high absorption layer 32, the resist film 28 shown in FIG. 15 is formed directly or via the antireflection film 34. After that, if the resist film 28 is patterned using the photomask 30, the standing wave effect is minimized,
The resist film 28 can be processed into a fine pattern with high accuracy.

In FIG. 18, 9.5 to 40 nm polysilicon is formed as a high absorption film on each of a silicon substrate and a tungsten silicide as a base substrate,
When a Si _X O _y N _z film (containing hydrogen H) having a film thickness of 20 to 150 nm is formed thereon and a resist film is formed thereon, the standing wave effect is obtained. Indicates.
As is clear from FIG. 18, regardless of the type of base substrate,
It was confirmed that the standing wave effect can be minimized in both cases as well.

In the experiment shown in FIG. 18, XP8843 was used as the resist. The resist n _PR and k _PR were 1.802 and 0.0107, respectively. The n _poly and k _poly of the polysilicon film were 1.68 and 3.27, respectively. The n _WSi and k _WSi of the tungsten silicide were 1.96 and 2.69, respectively. N _sub and k of the semiconductor substrate
_{The sub} was 1.572 and 3.583, respectively. The n _arl and k _arl of the Si _x O _y N _z film were 2.15 and 0.67, respectively.

KrF having a wavelength λ of 248 nm was used as the exposure light. Further, the Si _X O _y N _z film is formed by using a parallel plate plasma CVD method, an ECR plasma CVD method, or a bias ECR plasma CVD method by using microwave (2.45 GHz) and SiH ₄ + O ₂ + N ₂
The film was formed using the mixed gas of.

Example 2 In Example 2, the effectiveness of the present invention was obtained in the same manner as in Example 1 except that titanium-based materials such as titanium nitride and titanium oxynitride were used as the high absorption film. Proved.

I line (365 nm), KrF (248 n)
m), TiN and TiON in ArF (193 nm)
Optical constant (refractive index n) and absorption coefficient α (l / nm)
Is as shown in Table 2 below.

[0061]

[Table 2]

From Table 2 above, in the same manner as in Example 1, in order to satisfy αd ≧ 2 in titanium-based materials such as titanium nitride and titanium oxynitride, d
It can be seen that the film thickness of 15 to 120 nm may be used. FIG. 19 shows a standing wave effect when a titanium nitride TiN film having a film thickness of 120 nm is formed on a silicon substrate and a resist is applied on the film. As a resist
XP8843 was used. The resist n _PR and k _PR are
It was 1.802 and 0.0107, respectively. Ti
The n _TiN and k _TiN of the N film were 2.19 and 1.6, respectively. N _sub and k _sub of the semiconductor substrate are
It was 1.57 and 3.58, respectively. KrF having a wavelength λ of 248 nm was used as the exposure light.

In FIG. 20, on the tungsten silicide,
A standing wave effect is also obtained when a TiN film having a film thickness of 120 nm is formed and a resist is applied on the film. XP8843 was used as the resist. The resist n _PR and k _PR were 1.802 and 0.0107, respectively. The n _TiN and k _TiN of the TiN film are 2.1, respectively.
9 and 1.6. N of tungsten silicide
_WSi and k _WSi are 1.96 and 2.69, respectively.
Met. The exposure light is K with a wavelength λ of 248 nm.
rF was used.

In both figures, the horizontal axis represents the resist film thickness, and the vertical axis represents the resist absorbed light amount which is the component that actually exposes the resist. Comparing FIG. 19 and FIG. 20, the same result is obtained. That is, even on a base substrate having a plurality of highly reflective layer regions having different reflectances, a titanium-based material such as TiN or TiON having a film thickness of 15 to 120 nm is formed on the entire surface of the base substrate to form the base substrate. Substantially equivalent to a substrate having only the same reflection.

Therefore, as shown in FIG. 15, by providing the high absorption layer 32 of the present embodiment on the entire surface of the underlying substrate 25 on which the regions A and B having different optical conditions are formed, the underlying substrate 25 is formed. Has been proved to be able to be treated optically as if it were a single substrate.

On the surface of the high absorption layer 32, the resist film 28 shown in FIG. 15 is formed directly or via the antireflection film 34. After that, if the resist film 28 is patterned using the photomask 30, the standing wave effect is minimized,
The resist film 28 can be processed into a fine pattern with high accuracy.

Example 3 This example 3 is the same as Example 1 except that a refractory metal such as tungsten or tungsten silicide or a refractory metal silicide material is used as the high absorption film. Proved its effectiveness.

I-line (365 nm), KrF (248n)
m), optical constants (refractive index n) and absorption coefficient α (l / nm) of W and WSi in ArF (193 nm) are as shown in Table 3 below.

[0069]

[Table 3]

From Table 3 above, in the same manner as in Example 1, αd ≧ 2 for refractory metals or refractory metal silicide materials such as tungsten and tungsten silicide.
It is understood that the film thickness d = 8 to 30 nm can be used to satisfy the above condition. In FIG. 21, 30n on a silicon substrate
a tungsten silicide WSi film having a thickness of m is formed,
The standing wave effect when a resist is applied on the film is shown. XP8843 was used as the resist. N of resist
_PR and k _PR are 1.802 and 0.010, respectively.
It was 7. The n _WSi and k _WSi of the WSi film were 1.96 and 2.69, respectively. N of semiconductor substrate
_sub and k _sub are 1.57 and 3.58, respectively
Met. The exposure light is K with a wavelength λ of 248 nm.
rF was used.

In FIG. 22, on the tungsten silicide,
A standing wave effect is also shown when a WSi film having a thickness of 30 nm is formed and a resist is applied on the film. XP8843 was used as the resist. N _PR and k of resist
_{The PR} was 1.802 and 0.0107, respectively. N _WSi and k _WSi of the WSi film are respectively 1.9.
6 and 2.69. The exposure light has a wavelength of λ
Used 248 nm KrF.

In both figures, the horizontal axis shows the resist film thickness, and the vertical axis shows the amount of resist absorption light which is the component that actually exposes the resist. Comparing FIG. 21 and FIG. 22, the same result is obtained. That is, a refractory metal such as W or WSi or a refractory metal silicide-based material having a film thickness of 8 to 30 nm or a refractory metal silicide-based material having a film thickness of 8 to 30 nm is formed on the entire surface of a base substrate even on a base substrate having a plurality of highly reflective layer regions having different reflectances. As a result, the underlying substrate is substantially equivalent to a substrate having only the same reflection. Therefore, as shown in FIG. 15, by providing the high absorption layer 32 of the present embodiment on the entire surface of the base substrate 25 on which the regions A and B having different optical conditions are formed, the base substrate 25 is optically It has been proved that it can be treated as a single substrate.

On the surface of the high absorption layer 32, the resist film 28 shown in FIG. 15 is formed directly or through the antireflection film 34. After that, if the resist film 28 is patterned using the photomask 30, the standing wave effect is minimized,
The resist film 28 can be processed into a fine pattern with high accuracy.

Fourth Embodiment In a fourth embodiment, as shown in FIG. 23, a method for actually manufacturing a fine pattern on a semiconductor device will be described. As shown in FIG. 23A, a gate electrode having a polycide structure including a polysilicon layer 22 and a tungsten silicide 24 is formed on a semiconductor substrate 20 formed of, for example, a silicon wafer, with a gate insulating layer interposed. A transparent insulating film 26 such as a silicon oxide film is formed thereon as a film to be processed. In the transparent insulating film 26, a region located above the tungsten silicide 24 and a region located above the impurity diffusion layer formed on the surface of the semiconductor substrate 20 are exposed at the time of exposing the underlying substrate 25 (polysilicon). Semiconductor substrate 2 on which silicon film 22, tungsten silicide film 24 and transparent insulating film 26 are formed
The optical conditions of 0) are different.

Therefore, in this embodiment, first, the high absorption film 32 is formed on the entire surface of the transparent insulating film 26. In this embodiment, as the high absorption film 32, a silicon-based material such as polysilicon, amorphous silicon, or doped silicon is used as in the first embodiment. The film thickness of the high absorption film 32 is, for example, 40 nm. By depositing a silicon-based material such as polycrystalline silicon, amorphous silicon, or doped polysilicon having a film thickness of 40 nm on the entire surface of the underlying substrate 25, the underlying substrate 25 is substantially a substrate having only the same reflection. Are equivalent to each other.

Next, an antireflection film 34 is formed on the surface of the high absorption film 32. As the antireflection film 34, for example, a Si _X O _y N _z film (containing hydrogen H) or a Si _X N _y film having a film thickness of about 30 nm is formed by parallel plate plasma CVD.
Method, ECR plasma CVD method, or bias ECR
Using the plasma CVD method, microwave (2.45GH
z) was used to form a film using a mixed gas of SiH ₄ + O ₂ + N ₂ .

Next, a resist film 28 was formed on the antireflection film 34. As the resist film 28, XP8
843 was used. Next, exposure was performed using a photomask to form fine patterns 40a and 40b on the resist 28. The exposure light is KrF having a wavelength λ of 248 nm.
Was used.

At this time, the high-absorption film 32 and the antireflection film 34 are positioned on the lower layer side of the resist film 28, so that the standing wave effect can be obtained even if regions under different optical conditions are formed on the base substrate 25. It was possible to almost eliminate the influence of the above, and it was possible to stably form good fine patterns 40a and 40b.

Next, in this embodiment, as shown in FIG. 23B, the antireflection layer 34 and the high absorption layer 32 were etched using the resist film 28 having the fine patterns 40a and 40b as a mask. When etching, C
Fluorine gas such as HF ₃ (50 to 100 SCCM) + O ₂ (30 SCCM) is used, and pressure of about 2 Pa is applied to 100 to 1
RIE with increased ionicity by applying power of about 000W
(Reactive ion etching) was performed.

Next, as shown in FIG. 23C, the resist 28 was removed using oxygen plasma. Next, FIG.
In the state shown in (C), the entire surface of the base substrate 25 was etched back. At the time of the etch-back treatment, fluorine gas was used, and a power of about 10 to 100 W was applied under a pressure of about 2 Pa, and the RIE was performed to perform etch-back. By this etch back, FIG.
As shown in (D) and (E), the antireflection film 34 made of the Si _X O _y N _z film or the Si _X N _y film and the high-absorption film 32 made of a silicon-based material are used as a transparent base film. It is etched together with the insulating film 26. The etch back process is performed by using the tungsten silicide layer 24 and the semiconductor substrate 2.
Fine contact holes 42a, 42 reaching the surface of 0
The process ends when b is formed.

At the time when the above-mentioned etch-back process is completed, a fine mask pattern is formed on the underlying substrate 25 having a plurality of highly reflective layers having different reflectances by a single exposure. Fifth Embodiment In a fifth embodiment, as shown in FIG. 23, a method of actually manufacturing a fine pattern on a semiconductor device will be described. 23. In the fifth embodiment, as compared with the fourth embodiment, a titanium-based material film (100 nm) such as titanium nitride or titanium oxynitride is used as the high absorption film 32.
At the time of etching the titanium-based material high absorption film 32 in the step shown in (B), RIE is performed using a chlorine-based gas, and FIG.
In the etch back process of the steps shown in 3 (C) to (E), C
A semiconductor device was manufactured in the same manner as in Example 4 except that a fluorine gas such as HF ₃ (50 to 100 SCCM) + C ₂ F ₂ (30 SCCM) was used.

The steps shown in FIGS. 23 (C) to 23 (D)
The etching selection ratio in ₂ / SiO_xN_y:
H = about 3-8, SiO₂ / TiN = 3-8
It was This etchback is due to the gate electrode and
Etching reaches the surface of the semiconductor substrate
It ends when you do.

At the time when the above etching is completed,
On a base substrate having a plurality of highly reflective layers with different reflectance,
A fine mask pattern can be formed by a single exposure. Sixth Embodiment In a sixth embodiment, as shown in FIG. 23, a method for actually manufacturing a fine pattern on a semiconductor device will be described. In the sixth embodiment, as compared with the fourth embodiment, as the high absorption film 32, a refractory metal such as tungsten or tungsten silicide or a refractory metal silicide-based material film (30 nm) is used.
23B, RIE is performed using a chlorine-based gas during the etching process of the high-absorption film 32 of the refractory metal or the refractory metal-based silicide-based material in the step shown in FIG.
In the etch back process of the steps shown in (C) to (E), CH
In the same manner as in Example 4 except that fluorine gas such as F ₃ (50 to 100 SCCM) + C ₂ F ₂ (30 SCCM) was used,
A semiconductor device was manufactured.

Also in this embodiment, a fine mask pattern can be formed on a base substrate having a plurality of highly reflective layers having different reflectances by a single exposure. Seventh Embodiment In a seventh embodiment, as shown in FIG. 24, a method of actually manufacturing a fine pattern on a semiconductor device will be described.

As shown in FIG. 24A, a gate electrode having a polycide structure composed of a polysilicon layer 22 and a tungsten silicide 24 is formed on a semiconductor substrate 20 made of, for example, a silicon wafer, with a gate insulating layer interposed therebetween. Form. A transparent insulating film 26 such as a silicon oxide film is formed thereon as a film to be processed. In the transparent insulating film 26, a region located above the tungsten silicide 24 and a region located above the impurity diffusion layer formed on the surface of the semiconductor substrate 20 are exposed at the time of exposing the underlying substrate 25 (polysilicon). The optical conditions of the semiconductor substrate 20) on which the silicon film 22, the tungsten silicide film 24, and the transparent insulating film 26 are formed are different.

Therefore, in this embodiment, the high absorption film 32 is first formed on the entire surface of the transparent insulating film 26. In this embodiment, as the high absorption film 32, a titanium-based material such as titanium nitride or titanium oxynitride is used as in the second embodiment. The film thickness of the high absorption film 32 is, for example, 1
00 nm. By forming the titanium-based material high absorption film 32 having a film thickness of 100 nm on the entire surface of the base substrate 25, the base substrate 25 becomes substantially equivalent to a substrate having only the same reflection.

Next, an antireflection film 34 is formed on the surface of the high absorption film 32. As the antireflection film 34, for example, a Si _X O _y N _z film (containing hydrogen H) or a Si _X N _y film with a film thickness of about 100 nm is used as a parallel plate plasma CV.
D method, ECR plasma CVD method, or bias EC
Using R plasma CVD method, microwave (2.45G
Was used to form a film using a mixed gas of SiH ₄ + O ₂ + N ₂ .

Next, a resist film 28 was formed on the antireflection film 34. As the resist film 28, XP8
843 was used. Next, exposure was performed using a photomask to form fine patterns 40a and 40b on the resist 28. The exposure light is KrF having a wavelength λ of 248 nm.
Was used.

At this time, the high-absorption film 32 and the antireflection film 34 are positioned on the lower layer side of the resist film 28, so that the standing wave effect can be obtained even if the regions where the optical conditions are different are formed on the base substrate 25. It was possible to almost eliminate the influence of the above, and it was possible to stably form good fine patterns 40a and 40b.

Next, in this embodiment, as shown in FIG.
So that the fine patterns 40a and 40b are formed.
Using the strike film 28 as a mask, the antireflection layer 34 and the high absorption layer
32 and the transparent insulating film 26 were sequentially etched. S
i_XO_yN_zMembrane (containing hydrogen H) or Si_XN_yWith a membrane
When etching the formed antireflection layer 34, S
₂ F₂ (5 to 30 SCCM), C_Four F₈ (30-70 SCCM)
+ CHF₃ (10-30SCCM), CHF₃ (50 to 10
0SCCM) + O ₂ Fluorine gas such as (3-20 SCCM) is used
Under a pressure of about 2 Pa, about 100 to 1000 W
RIE (reactive
Ion etching) was performed.

The etching of the titanium-based high absorption film 32 is performed by
It was performed using a chlorine-based gas. The etching of the transparent insulating film 26 is performed by S ₂ F ₂ (5 to 30 SCCM) and C ₄ F ₈ (30 to 7).
0 SCCM) + CHF ₃ (10 to ₃₀ SCCM), CHF ₃ (5
Fluorine gas such as 0 to 100 SCCM) + O ₂ (3 to 20 SCCM) is used, and pressure of about 2 Pa is applied to 100 to 1000.
It was performed by RIE (reactive ion etching) with an increased ionicity by applying a power of about W. This etching ends when the etching reaches the surface of the gate electrode having the tungsten silicide film 24 and the surface of the active layer of the semiconductor substrate 20. By this etching, the contact holes 42a and 42b having a fine pattern were formed in the transparent insulating film 26.

Next, as shown in FIG. 24C, the resist 28 was removed using oxygen plasma. Next, FIG.
In the state shown in FIG.
4 (D), the contact holes 42a, 42
A titanium film 46 and a titanium nitride film 48 were formed to a thickness of about 2 nm and 30 nm, respectively, so as to enter the inside of b.
This is a layer serving as an adhesion layer when a wiring structure is formed using selective tungsten.

After that, the conductive plug layers 44a and 44b made of tungsten were buried in the contact holes 42a and 42b by using the selective growth method using tungsten. After that, the conductive plug layers 44a and 44b made of tungsten are etched back using a fluorine-based gas, and then a titanium film 46, a titanium nitride film 48, SiO _x N _y : H or Si _x N _y, etc. And the titanium-based high absorption film 32
Was removed using a chlorine-based gas.

As a result, as shown in FIG. 25F, it was possible to obtain a semiconductor device in which the conductive plug layers 44a and 44b were buried in the fine pattern contact holes 42a and 42b. Example 8 In this example, the Si shown in Examples 1 to 7 above is used.
_A fine pattern was formed on the semiconductor device in the same manner as in these examples except that the _x O _y N _z film was formed by the following method to form the antireflection film.

That is, in this embodiment, the parallel plate plasma CVD method, the ECR plasma CVD method, or the bias ECR plasma CVD method is used, and SiH ₄ + O ₂ + N ₂ of microwave (2.45 GHz) is used. An antireflection film was formed using a mixed gas or a mixed gas of SiH ₄ + N ₂ O.

Example 9 In this example, Si shown in Examples 1 to 7 was used.
_A fine pattern was formed on the semiconductor device in the same manner as in these examples except that the _x O _y N _z film was formed by the following method to form the antireflection film.

That is, in this embodiment, the parallel plate plasma CVD method, the ECR plasma CVD method, or the bias ECR plasma CVD method is used, and SiH ₄ + O ₂ + N ₂ of microwave (2.45 GHz) is used. Using mixed gas or SiH ₄ + N ₂ O mixed gas,
An antireflection film was formed using Ar as a buffer gas.

Example 10 In this example, Si shown in Examples 1 to 7 was used.
_A fine pattern was formed on the semiconductor device in the same manner as in these examples except that the _x O _y N _z film was formed by the following method to form the antireflection film.

That is, in this embodiment, the parallel plate type plasma CVD method, the ECRCVD method, or the bias EC is used.
The RCVD method was used to form a film using a mixed gas of SiH ₄ + O ₂ + N ₂ or a mixed gas of SiH ₄ + N ₂ O.

Example 11 In this example, Si shown in Examples 1 to 7 was used.
_A fine pattern was formed on the semiconductor device in the same manner as in these examples except that the _x O _y N _z film was formed by the following method to form the antireflection film.

That is, in this embodiment, the parallel plate plasma CVD method, the ECR plasma CVD method, or the bias ECR plasma CVD method is used, and SiH ₄ + O _{2 is used.}
A + N ₂ mixed gas or SiH ₄ + N ₂ O mixed gas was used, and Ar was used as a buffer gas to form a film.

Example 12 In this example, the Si shown in the above Examples 1 to 7 was used.
The _x N _y film, except that to form an antireflection film was formed by the following method, in the same manner as those in Example, was formed a fine pattern on a semiconductor device.

That is, in this embodiment, a parallel plate plasma CVD method, an ECR plasma CVD method, or a bias ECR plasma CVD method is used, and SiH ₄ + NH ₃ mixed gas is used by using microwave (2.45 GHz). Alternatively, an antireflection film was formed using a SiH ₂ C1 ₂ + NH 3 mixed gas.

Example 13 In this example, Si shown in Examples 1 to 7 above is used.
The _x N _y film, except that to form an antireflection film was formed by the following method, in the same manner as those in Example, was formed a fine pattern on a semiconductor device.

That is, in this embodiment, a parallel plate plasma CVD method, an ECR plasma CVD method, or a bias ECR plasma CVD method is used, and a microwave (2.45 GHz) is used to produce a SiH ₄ + O ₂ mixed gas, Alternatively, the antireflection film was formed using SiH ₂ C1 ₂ + NH ₃ mixed gas and Ar as a buffer gas.

Example 14 In this example, Si shown in Examples 1 to 7 was used.
The _x N _y film, except that to form an antireflection film was formed by the following method, in the same manner as those in Example, was formed a fine pattern on a semiconductor device.

That is, in the present embodiment, the parallel plate plasma CVD method, the ECR plasma CVD method, or the bias ECR plasma CVD method is used, and SiH ₄ + NH is used.
_The antireflection film was formed by using ₃ mixed gas or SiH ₂ C1 ₂ + NH ₃ mixed gas.

Example 15 In this example, Si shown in Examples 1 to 7 above is used.
The _x N _y film, except that to form an antireflection film was formed by the following method, in the same manner as those in Example, was formed a fine pattern on a semiconductor device.

That is, in this embodiment, the parallel plate plasma CVD method, the ECR plasma CVD method, or the bias ECR plasma CVD method is used, and SiH ₄ + O _{2 is used.}
An antireflection film was formed by using a mixed gas or SiH ₂ C1 ₂ + NH ₃ mixed gas and Ar as a buffer gas.

[0110]

As described above, according to the present invention, even on an underlying substrate having a plurality of regions having steps and different optical conditions, the length is shorter than the i-line (365 nm). By using light of a wavelength such as i-line, KrF or ArF excimer laser as a light source, a fine resist pattern can be formed satisfactorily and stably by a single exposure.

The method of manufacturing a fine pattern according to the present invention is
In particular, it can be suitably used for a method of manufacturing a semiconductor device having a fine pattern.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing light interference in a resist film.

FIG. 2 is a diagram showing a standing wave effect on a silicon substrate.

FIG. 3 is a diagram showing a standing wave effect on aluminum silicide.

FIG. 4 is a diagram showing a standing wave effect on tungsten silicide.

FIG. 5 is a diagram for estimating the influence of a step on the standing wave effect.

FIG. 6 is a graph showing the relationship between the fluctuation of the amount of absorbed light and the fluctuation of the pattern dimension.

FIG. 7 is a cross-sectional view showing a problem in forming a fine pattern on a base substrate on which a plurality of regions having different reflectances are formed.

FIG. 8 is a graph showing that when the reflectance of the underlying substrate is different, the absorption amount of the resist is different.

FIG. 9 is a diagram showing a standing wave effect on a silicon substrate.

FIG. 10 is a diagram showing contour lines of the amount of absorbed light when the film thickness of the antireflection film is fixed and the optical constants n and k are changed.

FIG. 11 is a diagram showing contour lines of absorbed light amount similar to FIG. 10 for other different resist film thicknesses.

FIG. 12 is a diagram showing contour lines of absorbed light amount similar to FIG. 10 for other different resist film thicknesses.

FIG. 13 is a diagram showing contour lines of absorbed light amount similar to FIG. 10 for other different resist film thicknesses.

FIG. 14 shows Si _x when manufacturing conditions are changed.
O is a graph showing changes in optical constants of _y N _z.

FIG. 15 is a cross-sectional view when a fine pattern is formed on a transparent insulating film of a semiconductor device.

FIG. 16 is a diagram showing a standing wave effect when a polysilicon film is formed on a silicon substrate.

FIG. 17 is a diagram showing a standing wave effect when a polysilicon film is formed on tungsten silicide.

FIG. 18 shows a polysilicon film formed on a silicon substrate or tungsten silicide, and a Si _X film is formed thereon.
The O _y N _z film is a graph showing the reduction of the standing wave effect in the case of film formation.

FIG. 19 is a diagram showing a standing wave effect after a titanium-based film is formed on a silicon substrate.

FIG. 20 is a diagram showing a standing wave effect after a titanium-based film is formed on tungsten silicide.

FIG. 21 is a diagram showing a standing wave effect after forming a tungsten silicide film on a silicon substrate.

FIG. 22 is a diagram showing a standing wave effect after forming a tungsten silicide film on tungsten silicide.

23A to 23E are cross-sectional views of the essential part showing the manufacturing process of a semiconductor device according to an example of the present invention.

24A to 24E are cross-sectional views of the essential part showing the manufacturing process of a semiconductor device according to another embodiment of the present invention.

25F is a sectional view of a key portion showing a step following that shown in FIG.

[Explanation of symbols]

 20 ... Semiconductor substrate 22 ... Polysilicon film 24 ... Tungsten silicide film 25 ... Underlying substrate 26 ... Transparent insulating film 28 ... Resist film 32 ... High absorption film 34 ... Antireflection film 42a, 42b ... Contact holes 44a, 44b ... Conductive plug layer

Claims (11)

[Claims] 1. A resist film having a predetermined pattern is formed by a photolithography method on a base substrate including at least two regions having mutually different optical conditions, and etching is performed using the resist as a mask to form the base substrate. A method of manufacturing a fine pattern to be processed, comprising the steps of forming a high-absorption film having a high light-absorbing property with respect to the wavelength of exposure light used in the photolithography step on the underlying substrate, and A fine pattern comprising: a step of forming an antireflection film on the substrate, a step of forming a resist film on the antireflection film, and a step of processing the resist film into a predetermined pattern by a photolithography method. Manufacturing method. 2. The method for producing a fine pattern according to claim 1, wherein the wavelength of the exposure light used in the photolithography step is in the range of 150 to 400 nm. 3. The method for producing a fine pattern according to claim 1, wherein the high absorption film is made of a silicon material. 4. The film thickness of the high absorption film is 9.5 to 40 n.
The method for producing a fine pattern according to claim 3, wherein m is m. 5. The method for producing a fine pattern according to claim 1, wherein the high absorption film is made of a titanium-based material. 6. The film thickness of the high absorption film is 15 to 120 n.
The method for producing a fine pattern according to claim 5, wherein m is m. 7. The method for producing a fine pattern according to claim 1, wherein the high absorption film is made of a material selected from the group consisting of refractory metals, refractory metal compounds and refractory metal silicides. 8. The film thickness of the high absorption film is 15 to 120 n.
The method for producing a fine pattern according to claim 7, wherein m is m. 9. The antireflection film has a refractive index (n) of 1.
9. The silicon-based film having a film thickness of 20 to 150 nm and containing at least nitrogen and having an extinction coefficient (k) of 1.8 or more and 2.6 or less and an extinction coefficient (k) of 1.8 or more and 2.6 or less. The method for producing a fine pattern according to any one of claims. 10. A resist film having a predetermined pattern is formed by a photolithography method on a film to be processed formed on a surface of a semiconductor substrate so that at least two regions having mutually different optical conditions are formed. A method of manufacturing a semiconductor device, comprising the step of etching the resist film as a mask to process the film to be processed, wherein the film to be processed has a wavelength of exposure light used in the photolithography step. A step of forming a high absorption film having high light absorption, a step of forming an antireflection film on the high absorption film, a step of forming a resist film on the antireflection film, and a photolithography method for forming the resist film. By using the resist film having the predetermined pattern as a mask, the antireflection film and the high absorption film are subjected to a predetermined pattern. And a step of etching the film to be processed by using the antireflection film and the high absorption layer having a predetermined pattern as a mask after the resist film is removed. Manufacturing method. 11. A resist film having a predetermined pattern is formed by a photolithography method on a film to be processed formed on a surface of a semiconductor substrate so that at least two regions having mutually different optical conditions are formed. A method of manufacturing a semiconductor device, comprising the step of etching the resist film as a mask to process the film to be processed, wherein the film to be processed has a wavelength of exposure light used in the photolithography step. A step of forming a high-absorption film having a high light-absorption property and made of any one of refractory metal, refractory metal compound, and refractory metal silicide; and forming an antireflection film on the high-absorption film And a step of forming a resist film on the antireflection film, and a step of processing the resist film into a predetermined pattern by a photolithography method. And a step of forming a hole in the film to be processed by etching the antireflection film, the high absorption film and the film to be processed into a predetermined pattern using the resist film having the predetermined pattern as a mask, and so as to enter the hole. , On the antireflection film,
A step of forming a base film made of any one of refractory metal, refractory metal compound and refractory metal silicide; and filling a conductive plug layer in the hole in which the base film is formed. And a step of etching the upper part of the underlying film, the antireflection film, the high absorption film and the conductive plug layer other than the inside of the hole by an entire surface etchback method. And a method for manufacturing a semiconductor device.