JP2953348B2 - Resist pattern forming method, antireflection film forming method, antireflection film, and semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a resist pattern using an antireflection film made of a silicon oxide film, the antireflection film, and a semiconductor device having the antireflection film.
About. In particular, the present invention, when the photoresist on the antireflection film formed on the underlying substrate is exposed by a single wavelength to form a resist pattern, the thickness of the antireflection film,
And using a novel anti-reflection film suitable for optimizing optical conditions such as refractive index, absorption refractive index, etc., so that the standing wave effect in the photoresist becomes a predetermined value ,
Resist pattern forming method capable of favorably forming fine resist pattern , antireflection film and antireflection
The present invention relates to a semiconductor device having a film. INDUSTRIAL APPLICABILITY The present invention can be used, for example, as a method of forming a fine pattern when manufacturing an electronic material (such as a semiconductor device).

[0002]

2. Description of the Related Art For example, in the photolithography technology, a state-of-the-art stepper (projection exposure machine) is
Using rF excimer laser light (248 nm) as a light source,
A lens with an NA of about 0.37 to 0.42 is mounted (for example, Nikon NSR1505EX1, Canon FP
A4500). Research and development of design rule devices in the sub-half micron (0.5 μm or less) region have been studied using these steppers.

A stepper uses light of a single wavelength as an exposure light source. It is widely known that when exposure is performed at a single wavelength, a phenomenon called a standing wave effect occurs.
The reason why the standing wave is generated is that optical interference occurs in the resist film. That is, as shown in FIG.
And the reflected light R from the interface between the resist PR and the substrate S
This is because interference occurs in the film of the resist PR .

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 this specification, the amount of light absorbed by the resist refers to the amount of light absorbed by the resist itself, excluding surface reflection, absorption by the metal when metal is present, and the amount of light emitted from the resist. Means the amount of The amount of the absorbed light becomes the energy for light reflection of the resist.

FIG. 2 shows the result of examining a change in the amount of absorbed light depending on the thickness of a resist film (XP8843) formed on a silicon substrate. As a light source for exposure, KrF of λ = 248 nm was assumed.

The degree of change in the amount of absorbed light is shown in FIG.
As can be understood from the comparison between FIG. 4 and FIG. 2, 3 and 4, XP8843 (Shipley) is used for the resist, but the underlying substrates are Si, Al-Si, and W-Si, respectively. That is, the degree of change in the amount of absorbed light is determined by the complex amplitude reflectance (R) that takes into account multiple interference determined by the optical constants (n, k) of the underlying substrate and the optical constants (n, k) of the resist. ((R) indicates a vector quantity having a real part and an imaginary part).

Here, the optical constant n is a reflection refractive index, and k is absorption.
And the two optical constants n and k are given by
It can be determined by (1), (2) and (3). I = I _o exp (−αd) (1) α = 4πk / λ (2) n ^* = n−ik (3) (in the above formula, n ^* is a transmission absorption rate, λ is the wavelength of the incident light, I
Is the light intensity at a certain depth d, and _IO is the intensity of the incident light.
Respectively. )

Further, in an actual device, as shown in FIG. 5, irregularities always exist on the substrate surface. For example, there is a protrusion In such as polysilicon. For this reason, when the resist film RP is applied, the thickness of the resist film differs between the upper part and the lower part of the step. That is, the resist film thickness d _PR2 on the protrusion In is smaller than the resist film thickness d _{PR1 in the} other portions.

[0009] standing wave effect, it differ by the thickness of the resist film are as above described, Therefore, change in the amount of light absorbed in the resist by being affected by the standing wave effect, come each change . As a result, the dimensions of the resist pattern obtained after the exposure and the phenomenon differ between the upper part and the lower part of the step. The effect of the standing wave effect on the pattern size becomes more pronounced as the pattern becomes finer when a stepper having the same wavelength and the same numerical aperture is used, and is a phenomenon that is commonly observed with any type of resist.

The effect of the standing wave effect on the pattern size becomes more pronounced as the pattern becomes finer when a stepper having the same wavelength and the same numerical aperture is used. FIG.
8 to Nikon NSR1505EX1 as a stepper
(Used exposure light source : λ = 248 nm, KrF excimer, N
A = 0.42) and XP8843 as a resist.
The effect of the standing wave effect when using (a chemically amplified resist of Shipley Microelectronics, Inc .; a polyvinylphenol-based resist containing a photoacid generator) is shown for each pattern size. Obviously, as the pattern becomes finer, the standing wave effect becomes more remarkable (the critical dimension shift CD-Shift of the 0.5 μm, 0.4 μm, 0.35 μm line and space pattern indicated by a circle in the figure). See also variation). 6 shows a case of a line and space pattern with an interval of 0.5 μm, FIG. 7 shows a case of a line and space pattern with an interval of 0.4 μm, and FIG. 8 shows a case of a line and space with an interval of 0.35 μm This is the case of a pattern, and the standing wave effect becomes more prominent as the size is reduced. This tendency is a phenomenon that is common to all types of resists.

The dimensional accuracy of a resist pattern in a photolithography step at the time of manufacturing a device such as a semiconductor device is generally ± 5%. Loose than ± 5% in total
Ku is considered the practical use is also permitted in, but the focus of the other,
Considering that variations due to other factors may occur, the pattern accuracy at the time of resist exposure is within ± 5
%. In order to achieve the dimensional accuracy of ± 5%, it is essential to reduce the standing wave effect.

FIG. 9 shows a dimensional change (vertical axis) of the resist pattern with respect to a change in the amount of absorbed light in the resist film (horizontal axis). From FIG. 9, it can be seen that, for example, in order to manufacture a 0.35 μm rule device, the variation in the amount of light absorbed by the resist film is required to be within 6% of the range.

[0013]

In order to meet the above-mentioned demands, antireflection techniques are being actively studied in various fields. However, even if the material of the base substrate and the resist to be used are determined, it is not always easy to determine the conditions of the antireflection film that can obtain an appropriate antireflection effect in that case. .

For example, on a gate structure where an antireflection film is indispensable (for example, tungsten silicide (W
In the pattern formation on the (-Si) film), it is not determined under what conditions the antireflection film has a variation in the amount of light absorbed by the resist film, for example, in a range of 6% or less. Naturally, no effective anti-reflective coating material has been found on such W-Si.

With respect to the structure using the W-Si material as a gate, a pattern is currently formed by a multilayer resist method or a die-containing resist. Therefore, it is considered essential to quickly establish an anti-reflection technology on W-Si.

In such a case, comprehensive conditions and specific conditions regarding an antireflection film for forming a stable fine pattern on an arbitrary base substrate are determined by using an arbitrary single wavelength as an exposure light source. If there is a means for obtaining the same, it is possible to find out, for example, under what conditions an antireflection film should be formed on W-Si as described above. However, such a method has not been proposed yet.

The present invention has been made in view of the above circumstances, and when a resist pattern is formed on an arbitrary underlying substrate using light of an arbitrary single wavelength as an exposure light source, the resist pattern is fine. However, a method of forming a resist pattern for forming a good and stable resist pattern, and a method of forming the resist pattern directly or via another layer on the substrate.
An antireflection film having an exposure wavelength of 150 to 45.
At 0 nm, a specific reflection refractive index n, absorption refractive index k and
And a silicon oxide film with a specific thickness
Provided are an anti-reflection film and a semiconductor device having the anti-reflection film.
The purpose is to provide.

[0018]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The present invention provides a semiconductor device having a multilayer structure,
Formed directly or via another layer on the underlying substrate
Photo-resist on the anti-reflection film composed of silicon oxide film
Exposing the resist with a single wavelength to form a resist pattern
A method for forming a resist pattern, comprising:
Forming an antireflection film made of a silicon-based film on the base substrate;
Resist in the photoresist at the time of exposure, depending on the type of
The variation of the standing wave effect due to the variation of
Values of the refractive index n and the absorption refractive index k of the antireflection film.
Film formation while adjusting film formation conditions
Provided is a method for forming a resist pattern, comprising the steps of:

In the present invention, the silicon oxide based film is S
i _x O _y (also referred to as SiO) means a film may include optional components such as hydrogen.

The undersubstrate is made of a metal having a high melting point surface.
Alternatively, use a substrate composed of a high melting point metal silicide-based material.
It can also be used. The refractory metal or refractory metal
Examples of silicide-based materials include tungsten and tungsten.
And silicide.

The undersubstrate is made of a metal having a low melting point surface.
A substrate composed of a system material can also be used. Said low
Aluminum, aluminum
-Silicon alloy, aluminum-silicon-copper alloy,
Copper and copper alloys can be exemplified.

The base substrate has a silicon-based surface.
A material made of a material can be used. The series
Single crystal silicon, polycrystalline silicon
, Amorphous silicon, doped polysilicon, etc.
can do.

In the present invention, the surface of the base substrate has a high melting point.
In the case of metal or refractory metal silicide material,
As the anti-reflection film, the exposure wavelength is 150-450 nm.
In this case, the reflection refractive index n is 1.0 or more and 3.6 or less,
Folding ratio k is 0.11 or more and 0.75 or less, and film thickness is 10 nm or less.
100 nm or less due to fluctuations in the thickness of the resist film.
Anti-reflection that minimizes the dispersion of the standing wave effect
It is preferable to form a stop film.

Alternatively, in the present invention, the surface of the underlying substrate is
For refractory metals or refractory metal silicide materials
Has an exposure wavelength of 150 to 450 as the antireflection film.
nm, the reflection refractive index n is 1.7 or more and 5.9 or less,
The absorption refractive index k is a positive number of 0.51 or less, and the film thickness is 25
is at nm more than 100nm or less, change of the thickness of the resist film
The dispersion of the standing wave effect due to motion
It is preferable to form an antireflection film.

In the present invention, the surface of the base substrate has a low melting point.
In the case of a metal-based material, an exposure wave is used as the antireflection film.
When the length is 150 to 450 nm, the reflection refractive index n is 1.
3 or more and 3.6 or less, absorption refractive index k is 0.2 or more and 1.5 or less
Below, the film thickness is 10 nm or more and 70 nm or less,
Minimum variation in standing wave effect due to film thickness variation
It is preferable to form an anti-reflection film such that

Alternatively, in the present invention, the surface of the underlying substrate is
In the case of a low melting point metal-based material, as the antireflection film,
When the exposure wavelength is 150 to 450 nm, the reflection refractive index n
Is 1.9 or more and 5.9 or less, and the absorption refractive index k is 0.2 or more.
0.75 or less, and the film thickness is 25 nm or more and 90 nm or less
In the case of the standing wave effect due to the fluctuation of the resist film thickness,
Form an anti-reflection film to minimize the fluctuation.
Is preferred.

In the present invention, the surface of the underlying substrate is made of silicon.
In the case of a radiation-based material, the exposure wavelength
Is 150 to 450 nm, and the reflection refractive index n is 1.8.
Not less than 2.6 and absorption refractive index k is not less than 0.1 and not more than 0.8
Below, the film thickness is 20 nm or more and 150 nm or less,
The variation of the standing wave effect due to the variation of
It is preferable to form an antireflection film having such a value.

In the method for forming an anti-reflection film and the method for forming a resist pattern according to the present invention, prior to actually forming the anti-reflection film, depending on the type of the base substrate, the presence of the photoresist in the photoresist at the time of exposure may be reduced. The reflection index n, the absorption index k, and the film thickness of the antireflection film under the condition where the wave effect is minimized are obtained by simulation, and the reflection index n and the absorption index k obtained by the simulation are approached. An anti-reflection film composed of a silicon oxide-based film is formed on the surface of the base substrate directly or through another layer to a thickness substantially equal to the thickness obtained by the simulation while adjusting the film formation conditions. It is preferable to form a film.
Preferably, the source gas contains a substance containing at least a hydrogen element.

The above-mentioned new antireflection film was determined by the following means. (I) For a resist film having an arbitrary thickness,
Contour lines of the amount of light absorbed in the resist film when the optical conditions (n, k) of the antireflection film are continuously changed (however, the thickness of the antireflection film is fixed) are obtained. (II) In the result of the contour line of the amount of absorbed light inside the resist at the thickness of each resist film obtained in the above (I), a common region where the difference in the amount of absorbed light is minimized is found, and the optical conditions limited by this common region Is the optical condition (n, k) at the film thickness of the antireflection film determined in (I). (III) By changing the thickness of the antireflection film,
By repeating the operation of (II), the optical constants (n, k) of each optimum condition for each film thickness of the antireflection film are obtained. (IV) An anti-reflection film of an actual material having an optical constant of the optimum condition obtained in the above (III) is found.

[0030]

Next, referring to the drawings, the above means (I) to (IV) for determining the comprehensive conditions of the antireflection film used in the present invention will be described more specifically. The resist film thickness between the maximum values or the minimum values of the standing wave effect is
Assuming that the refractive index of the resist is n _PR and the wavelength of the exposure light is λ, it is given by λ / 2n _PR (see FIG. 10). Assuming an anti-reflection film ARL between the resist and the underlying substrate, its thickness d _arl and its optical constants are n _arl and k _arl . Focusing on the film thickness at a certain point (for example, the film thickness at which the standing wave effect is maximized) in FIG. 10, the case where the film thickness d _arl of the antireflection film is fixed and n _arl and k _arl are changed. The amount of light absorbed by the resist film at that point changes.
When this changing locus, that is, the contour line of the amount of absorbed light is obtained, the result is as shown in FIG. FIG. 11 corresponds to FIG. 11 when repeating at four locations at λ / 8n _PR intervals on the basis of at least the film thickness that maximizes or minimizes the standing wave effect for other different resist film thicknesses d _PR . 12 to 14 are obtained (FIGS. 11 to 14 show the case where the antireflection film thickness is specified as 20 nm and the resist film thickness is 985 n each).
m, 1000 nm, 1018 nm, and 1035 nm are shown). The above corresponds to the above-mentioned means (I).

The common areas of the graphs in FIGS. 11 to 14 show areas where the amount of absorbed light in the resist film does not change even if the resist film thickness changes for a specific antireflection film thickness. . That is, the common area is an area where the standing wave effect is minimized and the antireflection effect is the highest.
Therefore, such a common area is found. The common area can be found, for example, simply by superimposing the respective figures (graphs) and taking the common area (of course, the common area may be searched by a computer). This corresponds to the above-mentioned means (II). next,
The above is repeated by continuously changing the thickness d of the antireflection film. For example, up to the first step, d =
Assuming that the operation is performed at 20 nm, the above is repeated with changing d. Thereby, the thickness d _{arl of the} antireflection film and the optical constants n _arl , k that minimize the standing wave effect
The condition of _arl can be specified. This corresponds to the above means (III).

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

[0033] In means of the (I) ~ (IV), was examined for the reflection preventing film can be suitably used in the process according to the present invention, a silicon-based film (Si _X O _y film) oxide is particularly suitable It turned out to be.

The optical conditions of this film can be largely changed by the film forming conditions, and the variation of the standing wave effect due to the fluctuation of the thickness of the resist film obtained by the above-mentioned method is obtained.
It is possible to easily form an anti-reflection film that meets the optical conditions of the anti-reflection film so as to minimize the stickiness .

The antireflection film made of the silicon oxide film can be easily formed by various CVD methods and thermal oxidation methods. For example, this film is made of a parallel plate type plasma C
VD method, ECR plasma CVD method, or bias E
Using CR plasma CVD method and microwave
A silane-based gas and a gas containing oxygen (for example, SiH ₄ +
A film can be formed using a mixed gas of O ₂ ). In this case, an argon Ar gas, an N ₂ gas, or the like can be used as a buffer gas.

Further, these Si _x O _y film, using the resist as a _{mask, CF 4, CHF 3, C} 2 F 6, C 4 F
₈ , SF ₆ , S ₂ F ₂ , and NF ₃ -based gas can be used as an etchant, and can be easily etched by RIE with increased ionicity by adding Ar. The RIE is about 2
It is preferable to perform the process under a pressure of about Pa and a power of about 10 to 100 W. The flow rate of the gas during RIE is not particularly limited, but is preferably 5 to 70 SCCM.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. However, needless to say, the present invention is not limited by the following examples. Embodiment 1 This embodiment is an embodiment for forming a stable resist pattern on a W-Si film by using KrF excimer lithography.

In this embodiment, before actually forming a resist pattern using an antireflection film, the following method is used.
The optimum optical conditions and film thickness of the anti-reflection film capable of minimizing the standing wave effect in the photoresist were determined. (1) XP8 on W-Si film without antireflection film
843 resist (Shipley Microelectronics Co., Ltd.) was applied and exposed to KrF excimer laser light having a wavelength of 248 nm.
Shown in From FIG. 15, the standing wave effect is about ± 20%. (2) In FIG. 15, the maximum value of the standing wave effect is, for example, when the resist film thickness is 985 nm. Focusing on the resist film thickness of 985 nm, and setting the thickness of the antireflection film to 30 nm
FIG. 16 shows the change in the amount of absorbed light in the resist film (the contour line of the amount of absorbed light) with respect to the change in the optical constants n _arl and k _arl of the antireflection film. (3) a resist film thickness of 1000 nm, 1017.5 nm,
The results obtained by repeating the above (2) for each of 1035 nm are shown in FIGS. 17, 18 and 19, respectively.

(4) As a result of _obtaining the common region of FIGS. 17 to 19, _narl = 4.9, _karl = 0.1 or _narl = 2.15, _karl = 0.67 were obtained. That is, when the film thickness of the anti-reflection film is 30 nm, the conditions to be satisfied by the optimum anti-reflection film are as _follows : _narl = 4.9, _karl = 0.1, or _narl = 2.15, _karl = 0. .67.

When the standing wave effect was obtained using these conditions, the results shown in FIGS. 20 and 21 were obtained. 20 and 21, the standing wave effect was extremely small, and was about ± 1% in each case. The standing wave effect was reduced to about 1/20 of that without the anti-reflection film. In addition,
The optical conditions of the antireflection film are different between FIG. 20 and FIG.

(5) The above operations (2) to (4) are performed when the thickness of the antireflection film is set to 30 nm. By repeating (2) to (4), the optimum condition of the antireflection film according to the thickness of the antireflection film is obtained. The results obtained are shown in FIGS. As shown in FIGS. 22 and 23, for the solution (Value) 1, as the antireflection film, the reflection refractive index n is 1.2 or more and 3.4 or less, and the absorption refractive index k is 0.16 or more and 0.7 or less.
2 and a film thickness of 10 nm or more and 100 nm or less is an optimal antireflection film. As for the solution (Value) 2, the reflection refractive index n is 1.9 or more and 5.7 or less as an antireflection film. It was found that those having an absorption refractive index k of 0 or more and 0.46 or less became an optimal antireflection film. The antireflection film having n and k matching the curves shown in FIGS. 22 and 23 is most preferable, but is not necessarily on the curves, and n is ± 0.6, preferably ± 0.2, and k is k. ± 0.3, preferably ± 0.2, more preferably ± 0.15, and even more preferably ± 0.1.
When it is in the range of 05, a sufficient anti-reflection effect is exhibited.

(6) It is determined whether there is a film type that satisfies the conditions to be satisfied by the anti-reflection film obtained in (5) above, using a spectroscopic ellipsometer (SOPRA, “Moss System”).
As a result, as shown in FIG. 24, it was found that n and k changed according to the flow ratio of SiH ₄ and O ₂ and the microwave output.
Among, if film formation under the conditions enclosed by ○ mark, Si _x O _y film (silicon oxide film, with SiO film referred to) is, FIG. 22,
It was found that 23 conditions were completely satisfied. That is,
When W-Si is used as the base substrate, preferably, the reflective refractive index n = 2.4 ± 0.6 and the absorption refractive index k = 0.7 ±.
0.2, a film thickness _{d = 30nm ± 10nm Si x O} y
If the film is used as an antireflection film, it is expected that the standing wave effect can be minimized.

Next, the Si _x O with the above optical conditions and film thickness was used.
_It was confirmed whether or not the standing wave effect was actually reduced by forming the _y film. As shown in FIG. 25, on the silicon substrate S, by laminating a W-Si which is a refractory metal silicide, on which, Si _x O _y consisting film antireflection film A
RL was deposited. That is, a 23.8 nm thick Si _x O _y film was formed using an ECR-CVD apparatus. The Si _x
O _y reflection refractive index n of the antireflection film ARL consisting film 2.
36 and the absorption refractive index k was 0.53. That S
on the antireflection film ARL consisting i _x O _y film, XP88
The result of forming a photoresist PR of 43 and examining the standing wave effect is shown in Example 1 in FIG.

For the sake of comparison, the result of examining the standing wave effect in the same manner except that the antireflection film was not formed is also shown in FIG.
6 is shown as Comparative Example 1. In Example 1, the standing wave effect was about ± 1.8%, and the standing wave effect was 1 / 1.5 as compared with the case of Comparative Example 1 in which the antireflection film was not used (± 21%). It was reduced to about 12.

With the structure shown in FIG.
A line width of 0.35μm rule, lambda as an exposure light source =
When photolithography was performed using a 248 nm KrF laser, a favorable resist pattern close to a mask pattern was obtained. Thereafter, the underlying substrate was etched using the resist pattern as a mask. First, Si _x
Etching of O _y film, CHF ₃ (50~100SCC
M) + O ₂ (3-20 SCCM) gas system and 2P
A desired pattern was etched by applying a power of about 100 to 1000 W under a pressure of about a and etching by a reactive etching (RIE) method in which Ar was added to increase the ionicity. Next, the undersubstrate W-Si gate G shown in FIG. 25 was etched by RIE or the like using a photoresist PR of a predetermined pattern as a mask. A W-Si gate G having a good fine pattern to which a fine resist pattern was transferred was obtained.

[0046] EXAMPLE 2 In this example, an antireflection film made of Si _x O _y film, except that was formed by the following method, in the same manner as in Example 1, to process the underlying substrate. That is, in this embodiment,
Parallel type plasma CVD method, ECR plasma CVD method, or using a bias ECR plasma CVD method, a microwave (2.45 GHz), with SiH ₄ + O ₂ mixed gas, composed of Si _x O _y film reflective An prevention film was formed. This anti-reflection film has O ₂ before the resist is formed.
May be performed. By performing this plasma treatment, the deactivation of the acid below the chemically amplified resist can be prevented, and the footing or overhang of the pattern edge of the resist can be prevented.

[0047] EXAMPLE 3 In this example, an antireflection film made of Si _x O _y film, except that was formed by the following method, in the same manner as in Example 1, to process the underlying substrate. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
Law, using the bias ECR plasma CVD method, a microwave (2.45 GHz), and SiH ₄ + O ₂ mixed gas, using the Ar or N ₂ as the buffer gas consists of Si _x O _y film reflective An prevention film was formed.

[0048] EXAMPLE 4 In this example, an antireflection film made of Si _x O _y film, except that was formed by the following method, in the same manner as in Example 1, to process the underlying substrate. That is, in this embodiment,
Using parallel plasma CVD, ECR plasma CVD, or bias ECR plasma CVD, Si
Using H ₄ + O ₂ mixed gas was formed an antireflection film made of Si _x O _y film.

[0049] Example 5 In this example, an antireflection film made of Si _x O _y film, except that was formed by the following method, to process the underlying substrate in the same manner as in Example 1. That is, in this embodiment, a parallel plate type plasma CVD method, an ECR plasma CVD method,
Using bias ECR plasma CVD, SiH ₄ +
And O ₂ mixed gas, using the Ar or N ₂ as the buffer gas, was formed an antireflection film made of Si _x O _y film.

[0050] EXAMPLE 6 In this example, an antireflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 1, a base substrate processed. That is, in the present embodiment, Si _x O etching _{y film, C 4 F 8 (30~70SCCM)} + C
Using a gas system of HF ₃ (10 to ₃₀ SCCM), 2 Pa
Under a pressure of about 100 to 1000 W, a reactive etching method of increasing the ionicity by applying a power of about 100 to 1000 W
The desired pattern was etched.

[0051] In Example 7 This example, the anti-reflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 1, a base substrate processed. That is, in this embodiment, the etching of the Si _x O _y film, using a gas system of S ₂ F ₂ (5~30SCCM), under a pressure of about 2 Pa, 100 to 1000 W
A desired pattern was etched by a reactive etching method in which ionicity was increased by applying a certain amount of power.

Embodiment 8 In this embodiment, as shown in FIG. 27, a low melting point metal material G such as Al, Al--Si, Al--Si--Cu is laminated on a silicon substrate S, and Then, the anti-reflection film ARL and a silicon oxide film Ox such as SiO ₂ are stacked as required, and the photoresist PR is subjected to photolithography using KrF excimer lithography. At this time, in this embodiment, as the antireflection film, use of Si _X O _y film. As Al-Si, in addition to a commonly used Al-Si alloy containing 1% by weight of Si, an alloy containing less or more Si can be preferably used. As Al-Si-Cu, for example, Si is about 1% by weight, and Cu can be preferably applied to those having about 0.1 to 2% by weight.
Not limited to these. Typically, 1% by weight of Si, Cu
It is a 0.5% by weight Al-Si-Cu alloy.

As an anti-reflection film used on a low melting point metal base substrate such as Al, Al-Si, Al-Si-Cu, etc.
i _X O _y film was found technique, material and the reflectivity of the underlying substrate, except that different, it was carried out in the same manner as in Example 1. That is, the following method was used. (1) Al, Al-Si, A without an anti-reflection film
An XP8843 resist (Shipley Microelectronics Co., Ltd.) was applied on an l-Si-Cu substrate, and a wavelength of 2
Exposure and development were performed using a 48 nm KrF excimer laser beam. FIG. 3 shows the standing wave effect at this time. According to FIG.
The standing wave effect is about ± 29.6%. (2) In FIG. 3, the maximum value of the standing wave effect is, for example,
This is when the resist film thickness is 982 nm. Focusing on the resist film thickness of 982 nm, and setting the thickness of the antireflection film to 30 nm
FIG. 28 shows contour lines of the amount of light absorbed in the resist film with respect to changes in the optical constants n _arl and k _arl of the antireflection film. (3) Resist film thickness 1000 nm, 1018 nm, 10
As a result of repeating the above (2) for each of 35 nm, the results are shown in FIGS. 29, 30, and 31, respectively.

(4) As a result of _finding the common area in FIGS. 28 to 31, _narl = 4.8, _karl = 0.45, or _narl = 2.0, _karl = 0.8. That is, when the thickness of the anti-reflection film is 30 nm, the conditions to be satisfied by the optimum anti-reflection film are as _follows : _narl = 4.8, _karl = 0.45 or _narl = 2.0, _karl = 0. .8. When the standing wave effect was obtained using these conditions, the results shown in FIGS. 32 and 33 were obtained. 32 and 33, the standing wave effect was extremely small, and in each case, the range was about 1% or less. The standing wave effect was reduced to about 1/60 of that without the anti-reflection film shown in FIG. 32 and 33 differ in the optical conditions of the antireflection film.

(5) The above operations (2) to (4) are performed when the thickness of the antireflection film is set to 30 nm. By repeating (2) to (4), the optimum condition of the antireflection film according to the thickness of the antireflection film is obtained. The obtained results are shown in FIGS. As shown in FIGS. 22 and 34, regarding the solution (Value) 1, as the antireflection film, the reflection refractive index n is 1.2 or more and 3.4 or less, and the absorption refractive index k is 0.4 or more and 1.4. The film having a film thickness of 10 nm or more and 100 nm or less is an optimal antireflection film, and the solution (Value) 2 has a reflection refractive index n of 1.9 or more and 5.7 or less as an antireflection film. Yes, absorption refractive index k is 0.2 or more and 0.62
The following were found to be optimal antireflection films. The antireflection film having n and k matching the curves shown in FIGS. 22 and 34 is most preferable, but is not necessarily on the curves, and n is ± 0.6, preferably ± 0.2, and k is k. ± 0.3, preferably ± 0.2, more preferably ± 0.15, and even more preferably ± 0.1.
When it is in the range of 05, a sufficient anti-reflection effect is exhibited.

(6) It was examined using a spectroscopic ellipsometer (SOPRA) whether or not there was a film type that satisfies the conditions to be satisfied by the antireflection film obtained in (5) above. As a result, as shown in FIG. 24, the optical constant changes in accordance with the film forming conditions when forming the Si _x O _y film by using the CVD method, as shown in FIG. I found it.
In FIG. 24, a region indicated by a circle of Al- (1%) Si satisfies the conditions of FIGS. That is, preferably,
Reflective refractive index n = 2.3 ± 0.6, Absorbing refractive index k = 0.8
0 ± 0.2, the use of the thickness 23 is ± 10nm Si _x O _y film as an antireflection film, it is expected that it is possible to minimize the standing wave effect.

Next, the Si _x O with the above optical conditions and film thickness was used.
Whether or not the standing wave effect was actually reduced by forming the _y film was confirmed. As shown in FIG. 27, a low melting point metal material layer G such as Al, Al-Si, Al-Si-Cu, etc. is laminated on a silicon substrate S. in was formed an antireflection film ARL consisting Si _x O _y film. That is, using an ECR-CVD apparatus, the output power is about 1000 W, and the flow rate ratio of SiH ₄ / O ₂ is:
An Si _x O _y film having a thickness of about 30 nm was formed under SiH ₄ rich conditions. Its Si _x O _y is a reflection refractive index n of the antireflection film ARL consisting film 1.83, absorption refractive index k of 0.75
Met. Antireflection film ARL made from the Si _x O _y film
A photoresist PR made of XP8843 was formed thereon, and the result of examining the standing wave effect is shown in Example 8 in FIG.

For the purpose of comparison, the result of the standing wave effect examined in the same manner except that the antireflection film was not formed is also shown as Comparative Example 2. In the eighth embodiment, the standing wave effect is about ± 2.
It was about 2% (1.4%), and the standing wave effect was reduced to about 1/20 of that in Comparative Example 2 in which the antireflection film was not used. With the structure shown in FIG. 27, the photoresist PR was subjected to photolithography using a KrF laser of λ = 248 nm as a light source for exposure with a line width of the rule of 0.35 μm. As a result, a good resist pattern close to a mask pattern was obtained. Was done.

Thereafter, the underlying substrate was etched using the resist pattern as a mask. First, the etching of the Si _x O _y film, CHF ₃ (50~100SCCM) + O
₂ Using a gas system of (3 to 20 SCCM), a reactive etching (RIE) method in which a power of about 100 to 1000 W is applied under a pressure of about 2 Pa to increase ionicity to perform desired etching. The pattern was etched. Next, the low-melting-point metal material layer G, which is a metal wiring material shown in FIG. 27 as a base substrate, was etched by RIE or the like using a photoresist PR of a predetermined pattern as a mask. A good fine pattern metal wiring layer to which the fine resist pattern was transferred was obtained.

[0060] In Example 9 This example, an antireflection film made of Si _x O _y film shown in Example 8 was formed by the following method. That is,
In this embodiment, a parallel plate type plasma CVD method, an ECR plasma CVD method, or a bias ECR plasma CV
Using method D, if necessary, use microwaves (2.45 GHz
Using z), a film was formed using a mixed gas of SiH ₄ + O ₂ . Note that Ar or N ₂ may be used as a buffer gas for the source gas. FIG. 2 shows the relationship between the antireflection film thickness and the optical characteristics to be satisfied by the optimum antireflection film by adjusting the gas flow ratio by such a CVD method.
2, the value on the curve in FIG. 34) or, for n, the value on the curve ± 0.6, and for k, the value on the curve ±
An anti-reflection film made of a Si _x O _y film in the range of 0.2 was successfully formed.

[0061] In Example 10 This example, an antireflection film made of Si _x O _y film shown in Example 8 was formed by the following method. That is,
In this embodiment, a film is formed by CVD using a mixed gas of SiH ₄ + O ₂ + N ₂ at a temperature of normal temperature to 500 ° C. under a pressure of 0.01 to 10 Pa. By this CVD method,
By adjusting the gas flow ratio, the values on the curves in the diagrams (FIGS. 22 and 34) showing the relationship between the antireflection film thickness and the optical characteristics to be satisfied by the optimum antireflection film, or n
Value ± 0.6 on the curve with respect to, could be satisfactorily deposited antireflection film made of Si _x O _y film within a range of values ± 0.2 on the curve with respect to k.

[0062] In Example 11 This example, an antireflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 8, the underlying substrate processed. That is, in the present embodiment, Si _x O etching _{y film, C 4 F 8 (30~70SCCM)} + C
Using a gas system of HF ₃ (10 to ₃₀ SCCM), 2 Pa
Under a pressure of about 100 to 1000 W, a reactive etching method of increasing the ionicity by applying a power of about 100 to 1000 W
The desired pattern was etched.

[0063] In Example 12 This example, an antireflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 8, the underlying substrate processed. That is, in this embodiment, the etching of the Si _x O _y film, using a gas system of S ₂ F ₂ (5~30SCCM), under a pressure of about 2 Pa, 100 to 1000 W
A desired pattern was etched by a reactive etching method in which ionicity was increased by applying a certain amount of power.

Embodiment 13 In this embodiment, an anti-reflection coating is formed on the base substrate in the same manner as in Embodiments 8 to 12, except that Cu which is a Cu-based metal material is used as the base substrate. A film was formed, a resist film was formed thereon, photolithography of the resist film was performed, and the antireflection film and the underlying substrate were etched using the resist film as a mask. In the same manner, the fine substrate could be finely processed with a favorable pattern by minimizing the standing wave effect even with the underlying substrate made of Cu.

Embodiment 14 In this embodiment, as shown in FIG. 36, a silicon base substrate G of single crystal silicon, polycrystalline silicon, amorphous silicon, doped polysilicon or the like is used as a base substrate S. An anti-reflection film ARL is laminated thereon, and the photoresist PR is subjected to photolithography using KrF excimer lithography. At this time, in this embodiment, as the antireflection film, use of Si _X O _y film. As an anti-reflection film used on silicon-based substrates such as single-crystal silicon, polycrystalline silicon, amorphous silicon, and doped polysilicon, the technique of finding a Si _X O _y film differs in the material and reflectance of the underlying substrate. The procedure was the same as in Example 1 except for the above. That is, the following method was used.

(1) XP88 on a Si-based substrate without an anti-reflection film
43 resist (Shipley Microelectronics Co., Ltd.) was applied and developed with an exposure machine using a KrF excimer laser beam having a wavelength of 248 nm as a light source. FIG. 37 shows the standing wave effect at this time. From FIG. 37, the standing wave effect is
About ± 20%. (2) In FIG. 37, the maximum value of the standing wave effect is, for example, when the resist film thickness is 985 nm. Focusing on the resist film thickness of 985 nm, and setting the thickness of the antireflection film to 30 nm
_Then , a change in the amount of absorbed light in the resist film with respect to a change in the optical constants n _arl and k _arl of the antireflection film is obtained. (3) Another plurality of resist film thicknesses were obtained, and the above (2) was repeated for each of them. (4) The results are shown and these common areas are determined.
Such an operation is determined for various antireflection film thicknesses, whereby the optimum value of the optical constant (n
Value, k value). For example, if the thickness of the antireflection film is 30
The optical conditions to be satisfied by the optimum anti-reflection film when nm is set are: _narl = 2.1 and _karl = 0.7. When the standing wave effect was obtained using the above conditions, the result shown in FIG. 38 was obtained. In FIG. 38, the standing wave effect in the case of the present example (with SiO) was extremely small and was ± 1% or less. ± 23% without anti-reflection coating (without SiO 2)
, The standing wave effect was reduced to about 1/23 or less.

(5) The above operations (2) to (4) are performed when the thickness of the antireflection film is set to 30 nm. By repeating (2) to (4), the optimum condition of the antireflection film according to the thickness of the antireflection film is obtained. (6) It was investigated using a spectroscopic ellipsometer (SOPRA) whether or not a film type satisfying the conditions to be satisfied by the antireflection film obtained in (5) above was present.

As a result, as in the first embodiment, Six _x
It has been found that the optical constants change as shown in FIG. 24 according to the film forming conditions when forming the O _y film by using the CVD method. The region indicated by the Si condition ○ in FIG. 24 satisfies the condition (4) described above. That is, in FIG.
The conditions of CVD are set so that the region shown by
i _x O if _y film antireflective film deposited consisting of the reflection refractive index n and the absorption refractive index k, the film thickness of the antireflection film 3
It approaches n _arl = 2.1 and k _arl = 0.7 which are optimal at 0 nm. Note that the allowable value of n is ± 0.6, the allowable value of k is ± 0.3, and the allowable value of the film thickness d is ± 10 nm. As a result, as shown in FIG. 36, a Si substrate shown in FIG.
Minimum a sign conditions, by forming a reflection preventing film consisting of Si _x O _y film, thereby forming a photoresist PR on it, when performing photolithography processing of the photoresist PR, the standing wave effect It is expected that can be.

Next, the Si _x O with the above optical conditions and film thickness was used.
Whether or not the standing wave effect was actually reduced by forming the _y film was confirmed. As shown in FIG. 36, on the silicon substrate S, near the condition of the Si condition 印 shown in FIG.
Was deposited Si _x O _y antireflection film ARL consisting film. That is, using an ECR-CVD apparatus, the flow rate ratio of SiH ₄ / O ₂ is about 30 when the Si _x O _y film is formed under the condition of SiH ₄ poor.
nm. Antireflection film A composed of the Si _x O _y film
The reflection refractive index n of the RL was 2.1, and the absorption refractive index k was 0.7. On the antireflection film ARL made from the Si _x O _y film, a photoresist P consisting XP8843
The result of examining the standing wave effect by forming R is shown in Example 14 in FIG. For comparison, a result of similarly examining the standing wave effect except that the antireflection film was not formed is also shown as Comparative Example 3.

In the fourteenth embodiment, the standing wave effect is approximately ± 1.
It was about 1%, and the standing wave effect was reduced to about 1/23 as compared with the case of Comparative Example 3 in which the antireflection film was not used (± 23%). Actually, in the structure shown in FIG. 36, the photoresist PR is exposed to light for exposure at a line width of 0.35 μm rule.
When photolithography was performed using a KrF laser of λ = 248 nm as a source , a good resist pattern close to a mask pattern was obtained.

Thereafter, the underlying substrate was etched using the resist pattern as a mask. First, the etching of the Si _x O _y film, CHF ₃ (50~100SCCM) + O
₂ Using a gas system of (3 to 20 SCCM), a reactive etching (RIE) method in which a power of about 100 to 1000 W is applied under a pressure of about 2 Pa to increase ionicity to perform desired etching. The pattern was etched. Next, the surface of the underlying substrate G made of the silicon-based material shown in FIG. 36 as the underlying substrate was etched by RIE or the like using the photoresist PR of a predetermined pattern as a mask. A good fine pattern to which the fine resist pattern was transferred was obtained.

Example 15 In this example, an anti-reflection film was formed in the same manner as in Example 14, except that the Si _X O _y film shown in Example 14 was formed by the following method. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
A film was formed by using a mixed gas of SiH ₄ + O ₂ by using a microwave (2.45 GHz) as necessary, using a method or a bias ECR plasma CVD method. In addition,
This source gas contains Ar or N as a buffer gas.
₂ may be used.

[0073] In Example 16 In this example, an antireflection film made of Si _x O _y film shown in Example 14 was formed by the following method. That is, in the present embodiment, a mixed gas of SiH ₄ + O ₂ + N ₂ is used at a temperature of normal temperature to 500 ° C. and 0.01 to 10 Pa
Under the pressure described above by CVD. By adjusting the gas flow ratio by this CVD method, the values on the curves in the diagrams (FIGS. 22 and 34) showing the relationship between the antireflection film thickness and the optical characteristics to be satisfied by the optimum antireflection film, or
value ± 0.6 on the curve with respect to n, could be satisfactorily deposited antireflection film made of Si _x O _y film within a range of values ± 0.2 on the curve with respect to k.

[0074] In Example 17 In this example, an antireflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 14, the underlying substrate processed. That is, in the present embodiment, Si _x O _y
Etching of the _{membrane, C 4 F 8 (30~70SCCM)} +
Using CHF ₃ (10-30 SCCM) gas system, 2P
Under a pressure of about a, a desired pattern was etched by a reactive etching method in which a power of about 100 to 1000 W was applied to increase ionicity.

[0075] In Example 18 This example, an antireflection film made of Si _x O _y film, by the following procedure, except that etching the resist pattern as a mask, in the same manner as in Example 14, the underlying substrate processed. That is, in the present embodiment, Si _x O _y
The film is etched using a gas system of S ₂ F ₂ (5 to 30 SCCM) under a pressure of about 2 Pa and 100 to 1000
A desired pattern was etched by a reactive etching method in which ionicity was increased by applying a power of about W.

Embodiment 19 In this embodiment, a mixed gas of SiH ₄ and O ₂ is used,
_{When an xOy} film was formed, it was confirmed that the formed film contained hydrogen. That is, in the above embodiment, a portion of the Si _x O _y film and thought have antireflection film, Si _x O _y H _z films (where, z may be 0)
It is thought that it was.

Embodiment 20 In this embodiment, as shown in FIGS. 39 and 40, the relationship between the resist thickness and the critical dimension in the first embodiment was actually examined. In each case, experiments were performed on W-Si using KrF excimer laser light. FIG.
9 shows a case of a 0.30 μm line and space pattern, and FIG. 40 shows a case of a 0.35 μm line and space pattern. In each case, a chemically amplified positive resist was used as the resist. As shown in FIGS. 39 and 40, it was confirmed that a pattern having a substantially constant line width was obtained regardless of the resist thickness.

Example 21 This example is a method for forming an antireflection film using an organic compound containing at least Si element as a raw material. When an organic compound is used as a raw material, the coverage of the antireflection film at the step portion is improved, that is, the difference in the thickness of the antireflection film between the flat portion and the vertical portion of the step is reduced, and the uniformity of the antireflection effect in the semiconductor device chip is improved The system is improved. Therefore, this embodiment is particularly effective in a device having a strict step because an organic compound having excellent step coverage (coverage of the step) is used as a source gas. As an organic compound, for example, TEO
S or OMCTS (Si ₄ O (CH ₃ ) 8; Si / O =
Ratio 1) or HMDS (Si ₂ O (CH ₃ ) 6; Si / O
Ratio = 2) can be used. In this embodiment, the film formation was performed using the parallel plate plasma CVD apparatus under the following film forming conditions. OMCTS = 50 sccm RF Power = 190 W Pressure = 332.5 pa (2.5 torr) Substrate temperature = 400 ° C. Distance between electrodes = 1 cm

Embodiment 22 In Embodiment 21, when it is desired to form a film having a higher ratio of Si, SiH ₄ or the like may be added as a Si source containing no O or N. Parallel plate plasma CV
The film forming conditions when the D apparatus is used are shown below. OMCTS = 50 sccm SiH ₄ = 5 sccm RF Power = 190 W Pressure = 332.5 pa (2.5 torr) Substrate temperature = 400 ° C. Distance between electrodes = 1 cm

In the above embodiments, the method of controlling the optical constant of the film mainly by using the gas flow ratio as a parameter has been described. However, the optical constant of the film can be controlled by using the film forming pressure, RF power and substrate temperature as parameters. .

[0081]

As described above, according to the method for forming a resist pattern according to the present invention, when a resist pattern is formed on an arbitrary base substrate using light of an arbitrary single wavelength as an exposure light source, The standing wave effect at the time of exposure can be minimized, and a favorable and stable resist pattern can be formed even if the resist pattern is fine.
Further, according to the antireflection film forming method according to the present invention, an antireflection film having an optical condition that minimizes the standing wave effect,
The film can be formed very easily, and its etching is also easy.

[Brief description of the drawings]

FIG. 1 is a view for explaining a problem of a conventional technique, and is a view showing light interference in a resist film.

FIG. 2 is a diagram illustrating a problem of the related art, and is a diagram illustrating a standing wave effect.

FIG. 3 is a diagram for explaining a problem of the related art, and is a diagram illustrating a standing wave effect.

FIG. 4 is a diagram for explaining a problem of the related art, and is a diagram illustrating a standing wave effect.

FIG. 5 is a diagram for explaining a problem of the related art, and is a diagram showing an influence of a step.

FIG. 6 is a diagram showing the effect of the standing wave effect.

FIG. 7 is a diagram showing the effect of the standing wave effect.

FIG. 8 is a diagram showing the effect of the standing wave effect.

FIG. 9 is a diagram illustrating a relationship between a variation in the amount of absorbed light and a variation in pattern dimension.

FIG. 10 is a diagram illustrating a standing wave effect.

FIG. 11 shows an anti-reflection film AR for a certain resist film thickness.
FIG. 9 is a diagram showing a locus of a change in the amount of absorbed light of the resist film (a contour line of the amount of absorbed light) when n _arl and k _arl are changed while the thickness of L is fixed.

FIG. 12 is a diagram showing trajectories (contour lines) for other different resist film thicknesses.

FIG. 13 is a diagram showing trajectories (contour lines) for other different resist film thicknesses.

FIG. 14 is a diagram showing trajectories (contour lines) for other different resist film thicknesses.

FIG. 15 is a diagram showing a standing wave effect to be solved.

FIG. 16 is a diagram showing a locus (contour of absorption light amount) of a change in absorption light amount of a resist film with respect to a change in n _arl and k _arl for a resist film thickness of 985 nm when the thickness of the antireflection film is 30 nm.

FIG. 17 is a diagram showing a locus (contour line) for a resist film thickness of 1000 nm.

FIG. 18 is a diagram showing a locus (contour line) for a resist film thickness of 1017.5 nm.

FIG. 19 is a diagram showing a locus (contour line) for a resist film thickness of 1035 nm.

FIG. 20 is a diagram showing a standing wave effect under optimal conditions (Example).

FIG. 21 is a diagram showing a standing wave effect under optimal conditions (Example).

FIG. 22 is a diagram showing the relationship between the thickness of an antireflection film and n as an optical condition.

FIG. 23 is a view showing the relationship between the thickness of an antireflection film and k as an optical condition.

24 is a diagram showing the behavior of the Si _x O _y film formation by CVD.

FIG. 25 is a cross-sectional view showing a film formation structure of an antireflection film according to another example.

26 is a diagram illustrating an anti-reflection effect of Si on _{W-Si x O y (25nm} ).

FIG. 27 is a cross-sectional view illustrating a film formation structure of an antireflection film according to another example.

FIG. 28 is a diagram showing a locus (a contour line of the amount of absorbed light) of a change in the amount of absorbed light of the resist film with respect to a change in n _arl and k _arl for a resist film thickness of 982 nm when the thickness of the antireflection film is 30 nm.

FIG. 29 is a diagram showing loci (contour lines) for a resist film thickness of 1000 nm.

FIG. 30 is a diagram showing a locus (contour line) for a resist film thickness of 1018 nm.

FIG. 31 is a diagram showing a locus (contour line) for a resist film thickness of 1035 nm.

FIG. 32 is a diagram showing a standing wave effect under optimal conditions.

FIG. 33 is a diagram showing a standing wave effect under optimal conditions.

FIG. 34 is a diagram showing the relationship between the thickness of an antireflection film and k as an optical condition.

FIG. 35 is a diagram showing optical constant characteristics according to film forming conditions of a Si _x O _y film.

FIG. 36 is a cross-sectional view showing a film formation structure of an antireflection film in another example.

FIG. 37 is a diagram showing a standing wave effect.

38 is a diagram illustrating an anti-reflection effect of the Si _x O _y film on Si (32 nm).

FIG. 39 is an operation explanatory view of another embodiment (0.30 μm L / S).

FIG. 40 is an operation explanatory view of another embodiment (0.35 μm L / S).

[Explanation of symbols]

 ARL Anti-reflection coating PR photoresist S Base substrate

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application Hei 4-87912 (32) Priority date Hei 4 (1992) March 11 (33) Priority claim country Japan (JP) (31) Priority Claim number Japanese Patent Application No. 4-244314 (32) Priority Date Hei 4 (1992) August 20 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-316073 (32) Priority (4) Japan (JP) (56) Reference JP-A-60-153125 (JP, A) JP-A-59-6540 (JP, A) JP JP-A-51-58072 (JP, A) JP-A-1-241125 (JP, A) JP-A-2-148731 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21 / 027 G03F 7/11 503 G03F 7/26

Claims (37)

(57) [Claims] (1) In a semiconductor device having a multilayer structure,
Oxidation formed directly on the ground substrate or through other layers
The photoresist is placed on the anti-reflection coating composed of silicon-based coating.
Exposing the resist with a single wavelength to form a resist pattern
Resist pattern forming method, The anti-reflection film composed of the silicon oxide-based film,
Depending on the type of underlying substrate, the photoresist
Variations in the standing wave effect due to variations in the resist film thickness
The reflection refractive index n of the antireflection film,
Adjust the film forming conditions so as to obtain the folding ratio k and the film thickness.
Having a step of forming a film from A method for forming a resist pattern. 2. The method according to claim 1, wherein the surface of the base substrate is made of a high melting point metal or a high melting point metal.
2. The method for forming a resist pattern according to claim 1, wherein the method is formed of a metal silicide-based material having a melting point . (3) The refractory metal is tungsten,
The refractory metal silicide material is tungsten silicide.
Is The method for forming a resist pattern according to claim 2. Wherein the surface of the underlying substrate with a low melting point metal material
The method for forming a resist pattern according to claim 1, wherein the method is configured. (5) The low melting point metal-based material is aluminum,
Aluminum-silicon alloy, aluminum-silicon
-Any of copper alloy, copper, copper alloy, The method for forming a resist pattern according to claim 4. 6. The method for forming a resist pattern according to claim 1, wherein a surface of said base substrate is made of a silicon-based material . 7. The silicon-based material is a single crystal silicon,
Polycrystalline silicon, amorphous silicon, doped polysilico
Is selected from the group consisting of The method for forming a resist pattern according to claim 6. 8. When the surface of the base substrate is a refractory metal or a refractory metal silicide-based material, the antireflection film has a reflection refractive index n of 1.0 or more at an exposure wavelength of 150 to 450 nm. The resist pattern forming method according to claim 1, wherein the antireflection film has an absorption refractive index k of 0.11 or more and 0.75 or less and a film thickness of 10 nm or more and 100 nm or less. 9. The refractory metal is tungsten,
The refractory metal silicide material is tungsten silicide.
Is A method for forming a resist pattern according to claim 8. 10. The surface of the base substrate is a refractory metal or
In the case of refractory metal silicide material, The antireflection film has an exposure wavelength of 150 to 450 nm.
And the reflection refractive index n is 1.7 or more and 5.9 or less,
The collection index k is a positive number of 0.51 or less, and the film thickness is 25 n
m or more and 100 nm or less, The method for forming a resist pattern according to claim 1. 11. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
Id, The method for forming a resist pattern according to claim 10. 12. The surface of the base substrate is a low melting point metal-based material.
In the case of The antireflection film has an exposure wavelength of 150 to 450 nm.
The refractive index n is 1.3 or more and 3.6 or less,
The collection index k is 0.2 or more and 1.5 or less, and the film thickness is 10
an antireflection film having a thickness of not less than 70 nm and not more than 70 nm, The method for forming a resist pattern according to claim 1. Claim 13 The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, The method for forming a resist pattern according to claim 12. 14. The surface of the base substrate is a low melting point metal-based material.
In the case of The antireflection film has an exposure wavelength of 150 to 450 nm.
And the reflection refractive index n is 1.9 or more and 5.9 or less,
The collection index k is 0.2 or more and 0.75 or less, and the film thickness is 2
An antireflection film having a thickness of 5 nm or more and 90 nm or less; The method for forming a resist pattern according to claim 1. 15. The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, The method for forming a resist pattern according to claim 14. 16. The surface of the base substrate is made of a silicon-based material.
In some cases, The antireflection film has an exposure wavelength of 150 to 450 nm.
And the reflection refractive index n is 1.8 or more and 2.6 or less,
The collection index k is 0.1 or more and 0.8 or less, and the film thickness is 20
an antireflection film having a thickness of 150 nm or more, The method for forming a resist pattern according to claim 1. 17. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
It is a kind selected from the group consisting of recons, The method for forming a resist pattern according to claim 16. 18. An anti-reflection film having a surface provided directly or via another layer on a base substrate made of a high melting point metal or a high melting point metal silicide-based material, wherein the anti-reflection film has an exposure wavelength Is 150 to 450 nm, the reflection refractive index n is 1.0 or more and 3.6 or less, the absorption refractive index k is 0.11 or more and 0.75 or less , and the film thickness is 10 nm or more and 100 nm or less. An anti-reflection film made of a silicon oxide-based film in which the variation of the standing wave effect due to the fluctuation becomes a minimum value. (19) The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
Id, The anti-reflection film according to claim 18. 20. The surface is made of high melting point metal or high melting point metal
Directly or on the underlying substrate made of a side material
An anti-reflection film provided through a layer of The antireflection film has an exposure wavelength of 150 to 450 nm.
And the refractive index n is 1.7 or more and 5.9 or less,
Positive number with a ratio k of 0.51 or less, film thickness of 25 nm or more and 100
nm or less, and a standing wave due to fluctuations in the thickness of the resist film
Silicon oxide type with minimum effect variation
Composed of a membrane, Anti-reflection film. 21. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
Id, The antireflection film according to claim 20. 22. Base material whose surface is made of low-melting metal material
Reflection provided directly or through other layers on the plate
A barrier film, The antireflection film has an exposure wavelength of 150 to 450 nm.
And the refractive index n is 1.3 or more and 3.6 or less, absorption / refraction
The ratio k is 0.2 or more and 1.5 or less, and the film thickness is 10 nm or more and 70.
nm or less, and a standing wave due to fluctuations in the thickness of the resist film
Silicon oxide type with minimum effect variation
Composed of a membrane, Anti-reflection film. 23. The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, An anti-reflection film according to claim 22. 24. Base material whose surface is made of low-melting metal material
Reflection provided directly or through other layers on the plate
A barrier film, The antireflection film has an exposure wavelength of 150 to 450 nm.
The refractive index n is 1.9 or more and 5.9 or less,
The ratio k is 0.2 or more and 0.75 or less, and the film thickness is 25 nm or more and 9
0 nm or less, standing due to variation in the thickness of the resist film
Silicon oxide that minimizes wave effect variation
Composed of system membranes, Anti-reflection film. 25. The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, The antireflection film according to claim 24. 26. Base substrate whose surface is made of silicon-based material
Anti-reflective coating, directly or through other layers
A stop film, The antireflection film has an exposure wavelength of 150 to 450 nm.
The refractive index n is 1.8 or more and 2.6 or less,
Rate k is 0.1 or more and 0.8 or less, and film thickness is 20 nm or more and 15
0 nm or less, standing due to variation in the thickness of the resist film
Silicon oxide that minimizes wave effect variation
Composed of system membranes, Anti-reflection film. 27. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
It is a kind selected from the group consisting of recons, The anti-reflection film according to claim 26. 28. A semiconductor device comprising a plurality of layers, comprising: an undersubstrate having a surface made of a refractory metal or a refractory metal silicide-based material; and When the exposure wavelength is 150 to 450 nm, the reflection refractive index n is 1.0 or more and 3.6 or less, and the absorption refractive index k is 0.11 or more.
An anti-reflection film made of a silicon oxide-based film having a thickness of 0.75 or less , a film thickness of 10 nm or more and 100 nm or less, and a variation in a standing wave effect due to a variation in the thickness of the resist film being a minimum value; , Semiconductor devices. 29. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
Id, 29. The semiconductor device according to claim 28. 30. A semiconductor device comprising a plurality of layers , the surface of which is made of a refractory metal or a refractory metal silicide-based material.
Exposure on the underlying substrate composed of, and directly or via another layer on the underlying substrate
When the wavelength is 150 to 450 nm, the reflection refractive index n is
1.7 or more and 5.9 or less, and the absorption refractive index k is 0.51 or less.
Positive number, film thickness of 25 nm or more and 100 nm or less, resist film
The variation of the standing wave effect due to the variation of
Anti-reflection made of silicon oxide based film
A semiconductor device having a film . 31. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
Id, The semiconductor device according to claim 30. 32. A semiconductor device comprising a plurality of layers, comprising : a base substrate having a surface made of a low-melting-point metal-based material ;
When the wavelength is 150 to 450 nm, the reflection refractive index n is
1.3 or more and 3.6 or less, and the absorption refractive index k is 0.2 or more.
5 or less, the film thickness is 10 nm or more and 70 nm or less,
Minimal variation in standing wave effect due to variation in film thickness
Of a silicon oxide-based film with a value of
A semiconductor device having an anti-reflection film . 33. The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, The semiconductor device according to claim 32. 34. A semiconductor device comprising a plurality of layers, comprising : a base substrate having a surface made of a low-melting-point metal-based material ;
When the wavelength is 150 to 450 nm, the reflection refractive index n is
1.9 or more and 5.9 or less, and the absorption refractive index k is 0.2 or more and 0.1 or more.
75 or less, and the film thickness is 25 nm or more and 90 nm or less.
The variation of the standing wave effect due to the variation of the
It is composed of a silicon oxide-based film with a small value
A semiconductor device having an antireflection film . 35. The low melting point metal-based material is aluminum.
Aluminum, silicon-alloy, aluminum-silicon
Con-copper alloy, copper, any of copper alloy, The semiconductor device according to claim 34. 36. A semiconductor device comprising a plurality of layers, comprising a base substrate having a surface made of a silicon-based material , and exposing the base substrate directly or through another layer.
When the wavelength is 150 to 450 nm, the reflection refractive index n is
1.8 or more and 2.6 or less, and the absorption refractive index k is 0.1 or more and 0.2 or less.
8 or less, the film thickness is 20 nm or more and 150 nm or less, and
The variation of the standing wave effect due to the variation of the
It is composed of a silicon oxide-based film with a small value
A semiconductor device having an antireflection film . 37. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
It is a kind selected from the group consisting of recons, The semiconductor device according to claim 36.