JP2897691B2 - 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 a novel antireflection film, the antireflection film,
And a semiconductor device having the antireflection film. In particular, the present invention provides a method for exposing a photoresist on an anti-reflection film formed on a base substrate to a single wavelength to form a resist pattern. From a silicon oxide-based material containing at least nitrogen suitable for optimizing optical conditions such as
Pattern forming method capable of forming a fine resist pattern satisfactorily by minimizing the standing wave effect in the photoresist using the anti-reflection film
Forming method, antireflection film and semiconductor having the antireflection film
Related to body devices.

[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 having a numerical aperture (NA) of about 0.37 to 0.42 is mounted (for example, Nikon NSR1505EX1, Canon FPA4500). Using these steppers,
Research and development of design rule devices in the sub-half micron (0.5 μm or less) region are being studied.

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 thin 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 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 absorbed light is the energy that causes the resist to undergo a photoreaction .

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 the exposure light, 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 ₀ 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 I ₀ is the light 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 PR 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 convex portion In is thinner than the resist film thickness _{d PR1} of 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, which does not affect 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 in 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 commonly observed in any kind of resist. The dimensional accuracy of a resist pattern in a photolithography process at the time of manufacturing a device such as a semiconductor device is generally ± 5%. Although the total is considered practicable be gentler than ± 5%, the focus of the other, combined consider also occur variations due to other factors, the pattern accuracy be kept within the ± 5% during resist exposure Is desired. This ± 5
In order to achieve% dimensional accuracy, it is essential to reduce the standing wave effect.

FIG. 9 shows a dimensional change of the resist pattern (vertical axis) with respect to a change in the amount of absorbed light in the resist film (horizontal axis).
Is shown. 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 absorbed light of 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 technique 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 base substrate using light of an arbitrary single wavelength as an exposure light source, the resist pattern is fine. Even preferably, a resist pattern forming method for forming a stable resist pattern, provided directly or via another layer on the substrate
An anti-reflection film having an exposure wavelength of 150 to 450
In nm, a specific reflection index n, absorption index k, and
And silicon nitride oxide film with specific thickness
Consists of an antireflection film and a plurality of layers having the antireflection film
It is an object to provide a semiconductor device.

[0018]

To achieve the above object, the present invention provides a semiconductor device comprising a plurality of layers.
At least silicon, oxygen and nitrogen formed on the underlying substrate
On anti-reflective coating composed of silicon nitride oxide based film
And then expose the photoresist with a single wavelength
A resist pattern forming method for forming a pattern.
An anti-reflection film comprising the silicon nitride oxide-based film
Is changed according to the type of the underlying substrate.
Of standing wave effect due to fluctuation of resist film thickness
The reflection skew of the antireflection film under the condition that the fluctuation becomes the minimum value
The film forming conditions are adjusted so that the refractive index n, the absorption refractive index k, and the film thickness become equal.
Resist pattern having a process of forming a film while adjusting the conditions
And a method for forming a blade .

The present invention also relates to a semiconductor comprising a plurality of layers.
In the apparatus, at least silicon formed on the underlying substrate,
A silicon nitride oxide film containing oxygen, nitrogen, and hydrogen
Single-wavelength photoresist on anti-reflective coating
A resist pattern that forms a resist pattern by more exposure
A silicon nitride oxide-based film.
The formed anti-reflection film, depending on the type of the underlying substrate,
For variations in resist film thickness of photoresist during exposure
Of the conditions under which the variation of the standing wave effect due to
The reflection refractive index n, absorption refractive index k and film thickness of the antireflection film
Process to adjust the film forming conditions
A method for forming a resist pattern.

In the present invention, the semiconductor device has a multilayer structure.
In a semiconductor device, at least the
The silicon nitride oxide-based film containing silicon, oxygen, and nitrogen is
SiO _x N _y H _z (where x is 0.40 to 1.30,
y is in the range of 0.09 to 0.35 and z is in the range of 0 to 0.85.
You. ) Composed of silicon oxynitride film
Is preferred.

Further, the resist pattern of the present invention is formed.
In the method, the surface of the underlying substrate is preferably
Containing materials or high melting point metal or high melting point metal
Made of side material or low melting point metal material
Is preferred. In this case, the silicon-based material
Crystalline silicon, polycrystalline silicon, amorphous silicon, dope
One type selected from the group consisting of
More preferably, the high melting point metal is tungsten,
The melting point metal silicide is tungsten silicide
Is more preferred. Further, the low melting point metal-based material is
Minium, aluminum-silicon alloy, aluminum
-More preferably one of silicon-copper alloy
No.

In the method for forming a resist pattern according to the present invention,
In this case, the surface of the underlying substrate is
In the case of a silicide-based material, the antireflection film is catadioptric.
The index n is 1.0 or more and 3.6 or less, and the absorption refractive index k is 0.11.
Not less than 0.75 and not more than 10 nm and not more than 100 nm
In the case of the standing wave effect due to the fluctuation of the resist film thickness,
SiO _x N _y H _z (here
Where x is 0.40 to 1.30 and y is 0.09 to 0.3
5, z is in the range of 0 to 0.85. )
The formation of an anti-reflection film composed of a silicon oxide film is
preferable.

Alternatively, the resist pattern of the present invention is formed.
In the method, the surface of the underlying substrate is made of a high melting point metal or a high melting point metal.
In the case of a point metal silicide-based material, the antireflection film
The refractive index n is 1.7 or more and 5.9 or less, and the absorption refractive index k is
Positive number of 0.51 or less, film thickness of 25 nm or more and 100 nm or less
The standing wave effect due to the variation in the thickness of the resist film.
SiO _x N _y H _z (this
Here, x is 0.40 to 1.30, and y is 0.09 to 0.3.
5, z is in the range of 0 to 0.85. Nitriding represented by)
The formation of an anti-reflection film composed of a silicon oxide film is
preferable.

In the method of forming a resist pattern according to the present invention,
In the case where the surface of the underlying substrate is a low melting point metal-based material,
The antireflection film has a reflection refractive index n of 1.3 or more and 3.6 or less.
Bottom, absorption refractive index k is 0.2 or more and 1.5 or less, and film thickness is 10
nm or more and 70 nm or less, and fluctuations in the thickness of the resist film
S that minimizes the dispersion of the standing wave effect due to
iOxNyHz (where x is 0.40 to 1.30, y
Is in the range of 0.09 to 0.35 and z is in the range of 0 to 0.85.
You. Reflection composed of silicon nitride oxide film
It is preferable to form a prevention film.

Alternatively, the resist pattern of the present invention is formed.
In the method, the surface of the underlying substrate is made of a low melting point metal-based material.
In this case, the antireflection film has a reflection refractive index n of 1.9 or more.
9 or less, absorption refractive index k is 0.2 or more and 0.75 or less, film thickness
Is not less than 25 nm and not more than 90 nm, and the thickness of the resist film is
The dispersion of the standing wave effect due to the fluctuation of
Such as SiO _x N _y H _z (where x is 0.49 to 1.3)
0, y ranges from 0.09 to 0.35, z ranges from 0 to 0.85
It is in. Composed of silicon nitride oxide film
It is preferable to form an antireflection film.

In the method for forming a resist pattern according to the present invention,
In this case, at least the surface of the underlying substrate is made of a silicon-based material.
In this case, the antireflection film has a reflection refractive index n of 1.8 or more.
2.6 or less, absorption refractive index k is 0.1 or more and 0.8 or less, film
The thickness is 20 nm or more and 150 nm or less, and the thickness of the resist film is
The variation of the standing wave effect due to the variation of the film thickness is the minimum value.
So that a _SiO x _N y _{H z} (wherein, x represents 0.40
1.30, y is 0.09 to 0.35, z is 0 to 0.85
In the range. Composed of silicon nitride oxide film
It is preferable to form an antireflection film to be formed.

In addition, the present invention provides a method for directly or
An anti- reflection film provided with another layer interposed therebetween,
At a light wavelength of 150 to 450 nm, a predetermined catadioptric
SiO _x N _y H _z having a refractive index n, an absorption refractive index k and a film thickness
(Where x is 0.40 to 1.30 and y is 0.09 to
0.35 and z are in the range of 0 to 0.85. )
Anti-reflective coating made of silicon nitride oxide film
Offer.

In the antireflection film, the surface has a high melting point.
Base material made of metal or high melting point metal silicide material
Reflection provided directly or through other layers on the plate
An anti-reflection film, wherein the anti-reflection film has an exposure wavelength of 150.
In the range of from 450 nm to 450 nm, the reflection refractive index n is 1.0 or more.
6 or less, absorption refractive index k is 0.11 or more and 0.75 or less, film
The thickness is 10 nm or more and 100 nm or less, and the thickness of the resist film is
The variation of the standing wave effect due to the variation of the film thickness is the minimum value.
So that a _SiO x _N y _{H z} (wherein, x represents 0.40
1.30, y is 0.09 to 0.35, z is 0 to 0.85
In the range. Composed of silicon nitride oxide film
It is preferred that

Alternatively, in the antireflection film, the surface is
Made of high melting point metal or high melting point metal silicide material
Provided directly or through another layer on the underlying substrate
An anti-reflection film, wherein the anti-reflection film has an exposure wavelength of
In the range of 150 to 450 nm, the reflection refractive index n is 1.7 or less.
Above 5.9, positive number with absorption refractive index k of 0.51 or less, film
The thickness is 25 nm or more and 100 nm or less, and the thickness of the resist film is
The variation of the standing wave effect due to the variation of the film thickness is the minimum value.
So that a _SiO x _N y _{H z} (wherein, x represents 0.40
1.30, y is 0.09 to 0.35, z is 0 to 0.85
In the range. Composed of silicon nitride oxide film
It is preferred that

In the antireflection film of the present invention, the surface
Is directly or on an underlying substrate made of a low melting point metal-based material.
An anti-reflection film provided with another layer interposed therebetween,
When the light 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
SiO _x N _y H _z (where x is 0,
40 to 1.30, y is 0.09 to 0.35, z is 0 to
It is in the range of 0.85. ) Silicon nitride oxide
It is preferred that it is composed of a film.

Alternatively, in the antireflection film of the present invention,
Is placed on an undersubstrate whose surface is made of a low-melting metal material.
An anti-reflective coating provided in contact with or through another layer
Therefore, when the exposure wavelength is 150 to 450 nm,
The refractive index n is 1.9 or more and 5.9 or less, and the absorption refractive index k is 0.2.
Not less than 0.75 and a film thickness of not less than 25 nm and not more than 90 nm.
Yes, variation in standing wave effect due to variation in resist film thickness
SiO _x N _y H _z (here,
Where x is 0.40 to 1.30 and y is 0.09 to 0.3
5, z is in the range of 0 to 0.85. )
It is preferable to be composed of a silicon oxide film.

In the antireflection film of the present invention, the surface
Directly or on a base substrate made of silicon-based material.
The anti-reflection film provided through another layer of
When the light 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
SiO _x N _y H _z (where x is a small value)
0.40 to 1.30, y is 0.09 to 0.35, z is 0
０．８0.85. Silicon nitride oxide represented by)
It is preferable to be composed of a membrane.

Further, the present invention provides a semiconductor device comprising a plurality of layers.
Body device, comprising: a base substrate; and
Is a predetermined reflection / refractive index n, absorption / refraction through other layers
SiO _x N _y H _z having a rate k and a film thickness (where x is
0.40 to 1.30, y is 0.09 to 0.35, z is 0
０．８0.85. Silicon nitride oxide represented by)
Device having an anti-reflection film composed of a reflection film
To provide .

The semiconductor device of the present invention preferably comprises
Whether the surface is refractory metal or refractory metal silicide material
An underlying substrate, and directly or on the underlying substrate
Exposure wavelength is 150-450 nm through the layer of
The reflection refractive index n is 1.0 or more and 3.6 or less, and the absorption refractive index is
k is 0.11 or more and 0.75 or less, and the film thickness is 10 nm or more and 1
00 nm or less, and is determined by fluctuations in the thickness of the resist film.
SiO _x N that minimizes the variation of the standing wave effect
_y H _z (wherein, x is from 0.04 to 1.30, y is 0.0
9 to 0.35, z is in the range of 0 to 0.85. )
-Reflection film composed of silicon nitride oxide film to be formed
And a semiconductor device having:

Alternatively, the semiconductor device of the present invention is preferably
In other words, the surface has a high melting point metal or high melting point metal silicide
A base substrate made of a material, on the base substrate, directly or
Exposure wavelength to 150-450nm through other layers
The refractive index n is 1.7 or more and 5.9 or less,
Positive ratio k is 0.51 or less, film thickness is 25 nm or more and 10
0 nm or less, standing due to variation in the thickness of the resist film
SiO _x N _y that minimizes the variation of the wave effect
H _z (wherein, x is from .40 to 1.30, y is 0.09
０．３0.35 and z are in the range of 0０〜0.85. )
An anti-reflection film composed of a silicon nitride oxide film
Is a semiconductor device having:

The semiconductor device of the present invention is preferably
An undersubstrate having a surface made of a low-melting metal material;
Exposure wavelength of 15 or more directly on the plate or through another layer
At 0 to 450 nm, the reflection refractive index n is 1.3 or more
3.6 or less, absorption refractive index k is 0.2 to 1.5, film
The thickness of the resist film is not less than 10 nm and not more than 70 nm.
The variation of the standing wave effect due to the thickness variation is the minimum value
Such SiO _x N _y H _z (where x is 0.40 to 1.
30, y ranges from 0.09 to 0.35, and z ranges from 0 to 0.85.
In the box. ) Composed of silicon nitride oxide film
And an anti-reflection film.

The semiconductor device according to the present invention preferably comprises
An undersubstrate having a surface made of a low-melting metal material;
Exposure wavelength of 15 or more directly on the plate or through another layer
The reflection refractive index n is 1.9 or more at 0 to 450 nm.
5.9 or less, absorption refractive index k is 0.2 or more and 0.75 or less,
The film thickness is 25 nm or more and 90 nm or less, and the resist film
The variation of the standing wave effect due to the variation of the film thickness is the minimum value.
So that a _SiO x _N y _{H z} (wherein, x represents 0.40
1.30, y is 0.09 to 0.35, z is 0 to 0.85
In the range. Composed of silicon nitride oxide film
And a reflection preventing film.

Further, the semiconductor device of the present invention is preferably
Or an undersubstrate whose surface is made of a silicon-based material,
Exposure wavelength directly on the ground substrate or through another layer
In the range of 150 to 450 nm, the reflection refractive index n is 1.8 or less.
2.6 or less, absorption refractive index k is 0.1 or more and 0.8 or less,
A resist film having a film thickness of not less than 20 nm and not more than 150 nm;
The variation of the standing wave effect due to the variation of
SiO _x N _y H _z (where x is 0.40 to
1.30, y is 0.09 to 0.35, z is 0 to 0.85
In the range. Composed of silicon nitride oxide film
And a reflection preventing film.

Further, according to the present invention, the underlying substrate is actually
Before film formation, depending on the type of the base substrate,
Under the condition that the standing wave effect in the photoresist is minimized,
The reflection refractive index n, absorption refractive index k, and film thickness of the
By simulation and by simulation
Approach the calculated refractive index n and absorption refractive index k
At the surface of the underlying substrate directly or through another layer,
An anti-static silicon oxide film containing at least nitrogen
While controlling the film formation conditions,
Request a film thickness approximately equal to the film thickness determined by the application
Item 10. A method for forming a resist pattern according to item 1 or 8.
You.

In the present invention, at least silicon
Materials containing oxygen and oxygen atoms as source gas
When the antireflection film is formed by the vapor phase growth method used,
The silicon and oxygen atoms contained in the source gas
It is preferable that the content ratio (Si / O) is 0.4 or more and 3 or less.
Good.

Further , SiH ₄ and
The antireflection film was formed by a vapor deposition method using N ₂ O.
When forming the film, the gas flow ratio of the SiH ₄ and N ₂ O
(SiH _{4 /} N ₂ O) is 0.4 or more and 3 or less
Is more preferred.

Further, according to the present invention, the antireflection film is actually used.
Before film formation, depending on the type of the base substrate,
Under the condition that the standing wave effect in the photoresist is minimized,
The reflection refractive index n, absorption refractive index k, and film thickness of the
By simulation and by simulation
Approach the calculated refractive index n and absorption refractive index k
At the surface of the underlying substrate directly or through another layer,
A silicon oxide film containing at least nitrogen and hydrogen
The anti-reflection film formed is adjusted while adjusting the flow ratio of the source gas.
Is approximately equal to the film thickness obtained by the simulation.
Provided is a method for forming a resist pattern formed with a film thickness.
You.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for forming an anti-reflection film and the method for forming a resist pattern according to the present invention are described below. Due to fluctuations in the thickness of the resist film
That minimizes the variation of the standing wave effect
Of SiO _x N _y H _z (where x is 0.40 to 1.3)
0 and y are in the range of 0.09 to 0.35, and z is in the range of 0 to 0.85. ), The reflection refractive index n, the absorption refractive index k, and the film thickness of the antireflection film composed of the silicon nitride oxide film are determined. It is preferable to form a film while adjusting the film forming conditions.

In this case, according to the present invention, when the antireflection film is formed by vapor phase growth using a substance containing at least a silicon element and an oxygen element as a source gas, the silicon element contained in the source gas may be used. It is preferable that the content ratio (Si / O) of oxygen and oxygen element is 0.4 or more and 3 or less.

Further, when the antireflection film is formed by a vapor phase growth method using SiH ₄ and N ₂ O as the source gas, the flow rate ratio of the gas of SiH ₄ and N ₂ O ( (SiH ₄ / N ₂ O) is preferably 0.4 or more and 3 or less.

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 in the resist at the thickness of each resist film obtained in (I) above, 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) The above operations (I) and (II) are repeated while changing the thickness of the anti-reflection film, and the optical constants (n, k) of each optimum condition for each thickness of the anti-reflection film are obtained. (IV) An anti-reflection film of an actual material having an optical constant under the optimum condition obtained in the above (III) is found.

Next, with reference 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. Between the maximum value of the standing wave effect, or resist film thickness between the minimum value, when the refractive index of the resist and n _PR, the wavelength of the exposure light is lambda, it is given by λ / 2n _PR (see FIG. 10) . An anti-reflection film ARL is formed between the resist and the underlying substrate, and the film thickness _dart and the optical constant are changed to _nart and k.
_art . One point in FIG. 10 (e.g., the standing wave effect film thickness becomes maximum) when focusing on the thickness of, _n art to secure the film thickness _{d art} of anti-reflection _{film, k art}
Is 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.

With respect to other different resist film thicknesses d _PR , at least at four positions at λ / 8n _PR intervals on the basis of at least the film thickness that maximizes or minimizes the standing wave effect.
12 to 14 corresponding to FIG.
(FIGS. 11 to 14 show that the antireflection film thickness is 20 n
m, and the resist film thicknesses are 985 nm and 1000, respectively.
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 indicate 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 means (II).

Next, the above operation is repeated while continuously changing the thickness d of the antireflection film. For example, if the operation is performed with d = 20 nm up to the first step, the above is repeated while changing d. This allows
Thickness d of the antireflection film so as to minimize the standing wave effect
_art , optical constants _nart , and _kart 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 works for all wavelengths,
It is applicable in principle to all base substrates.

When the antireflection film which can be suitably used in the method according to the present invention was examined by means of the above (I) to (IV), a silicon oxide film containing nitrogen (SiO
_x N _y film) or nitrogen and a silicon oxide film containing hydrogen _{(SiO x} N y _{H z} films) have been found to be particularly suitable.

The optical conditions of these films can be greatly changed depending on the film formation conditions .
It is possible to easily form an anti-reflection film adapted to the optical conditions of the anti-reflection film so as to minimize the variation .

These antireflection films can be easily formed by various CVD methods. For example, these films are formed by a parallel plate type plasma CVD method, an ECR plasma CV
A mixed gas of a silane-based gas and a gas containing oxygen and nitrogen (for example, SiH ₄ + O ₂ + N ₂ ), or a silane-based gas and nitrogen using a microwave by a D method or a bias ECR plasma CVD method. The film can be formed using a mixed gas of a mixed gas (for example, SiH ₄ + N ₂ O). At that time, an argon Ar gas, an N ₂ gas, or the like can be used as a buffer gas.

Further, these SiO _x N _y H _z films are formed using CF ₄ , CHF ₃ , C ₂ F ₆ , C
_{4 F 8, SF 6, S} 2 F 2, the NF ₃ series gas as an etchant, by the addition of Ar RIE with increased ionic, can be easily etched. That RIE
Is preferably performed under a pressure of about 2 Pa and applying 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.

[0055]

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 the present embodiment, before actually forming a resist pattern using an anti-reflection film, the following method is used to optimize the optimal optical conditions of the anti-reflection film capable of minimizing the standing wave effect in the photoresist and The film thickness was 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 _art and k _art 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 finding the common area in FIGS. 17 to 19, _nart = 4.9, _kart = 0.1 or _nart = 2.15, _kart = 0.6.
7 was obtained. That is, when the film thickness of the antireflection film is 30 nm, the conditions to be satisfied by the optimum antireflection film are _nart = 4.9, _kart = 0.1 or _nart = 2.15, _kart = 0. .6
7 When the standing wave effect is obtained using these conditions, FIGS.
Were obtained. 20 and 21, the standing wave effect is extremely small, and in each case, about ± 1%
Met. 1/20 compared to the case without anti-reflection coating
The standing wave effect has been reduced to some extent. 20 and 21.
And the optical conditions of the antireflection film are different.

(5) The above operations (2) to (4) are performed when the thickness of the antireflection film is set to 30 nm. Also, (2)
By repeating (4) to (4), the optimum condition of the antireflection film according to the thickness of the antireflection film is obtained. Figure 2 shows the result.
2 and 23. As shown in FIGS. 22 and 23, the solution (Va
lue) 1, as an antireflection film, the reflective refractive index n is 1.2 or more and 3.4 or less, and the absorption refractive index k is 0.1 or less.
16 to 0.72 and a film thickness of 10 nm to 10
A film having a thickness of 0 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, and the absorption refractive index k
It was found that a film having a value of 0 or more and 0.46 or less was an optimal antireflection film. Antireflection films having n and k matching the curves shown in FIGS. 22 and 23 are most preferable, but not necessarily on the curves, and n is ± 0.6, preferably ± 0.2, and k is Is within the range of ± 0.3, preferably ± 0.2, more preferably 0.15, and still more preferably ± 0.05.

(6) A spectroscopic ellipsometer (SOPRA, “Moss”) is used to determine whether there is a film type that satisfies the conditions to be satisfied by the antireflection film obtained in (5).
system "). As a result, SiO _x
The N _y film corresponding to the film formation conditions for forming a film using a CVD method, optical constants were found to exhibit a change shown in FIG. 24. The area indicated by a circle in FIG. 24 satisfies the conditions of FIGS. That is, preferably, the reflection refractive index n = 2.4.
± 0.6, absorption refractive index k = 0.7 ± 0.2, film thickness d = 2
It is expected that the standing wave effect can be minimized if an SiO _x N _y film having a thickness of 5 nm ± 10 nm is used as an antireflection film.

Next, the above optical conditions and film thickness of SiO _x
Indeed standing wave effect by depositing N _y film was confirmed whether is reduced. As shown in FIG. 25, W-Si, which is a refractory metal silicide, is laminated on a silicon substrate S.
It was deposited antireflection film ARL consisting _x N _y film. That is, using an ECR-CVD apparatus, the microwave output was set to about 830 W, and the flow rate ratio of SiH ₄ / N ₂ O was set to SiH ₄
An SiO _x N _y film was formed at 23.8 nm under rich conditions. As a _SiO x _{N y} reflection refractive index n of the antireflection film ARL consisting film 2.36, absorption refractive index k is 0.53
Met. The anti-reflection film AR made of the SiO _x N _y film
A photoresist PR made of XP8843 was formed on L, and the result of examining the standing wave effect was shown in Example 1 in FIG.
Shown in

For 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 1. In the first embodiment, the standing wave effect is approximately ± 1.
It was about 8%, and the standing wave effect was reduced to about 1/12 compared to the case of Comparative Example 1 in which the antireflection film was not used (± 21%).

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, SiO
etching of _x N _{y film,} CHF 3 _(50~100SC
CM) + O ₂ (3-20 SCCM) gas system
Reactive etching (RI) in which ionicity is increased by applying a power of about 100 to 1000 W under a pressure of about Pa
The desired pattern was etched by the method E).

Next, the WS shown in FIG.
The i-gate G was etched by RIE or the like using the photoresist PR of a predetermined pattern as a mask. W-S of good fine pattern with fine resist pattern transferred
An i-gate G was obtained.

Embodiment 2 In this embodiment, an anti-reflection film made of a SiO _x N _y film is used.
An undersubstrate was processed in the same manner as in Example 1 except that a film was formed by the following method. That is, in this embodiment,
Using a parallel plasma CVD method, an ECR plasma CVD method, or a bias ECR plasma CVD method, using microwaves (2.45 GHz), SiH ₄ + O ₂ +
An anti-reflection film made of a SiO _x N _y film was formed using a N ₂ mixed gas or a SiH ₄ + N ₂ O mixed gas.

Embodiment 3 In this embodiment, an anti-reflection film made of a SiO _x N _y film was used.
An undersubstrate was processed in the same manner as in Example 1 except that a film was formed by the following method. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
Method, bias ECR plasma CVD method, and using microwave (2.45 GHz), SiH ₄ + O ₂ + N
₂ mixed gas or a _SiH 4 + _{N 2} O gas mixture, by using the Ar or _{N 2} as the buffer gas, SiO _x
It was deposited antireflection film consisting of N _y film.

Embodiment 4 In this embodiment, an anti-reflection film made of a SiO _x N _y film was used.
An undersubstrate was processed in the same manner as in Example 1 except that a film was formed by the following method. That is, in this embodiment, the parallel plasma CVD method, the ECR plasma CVD
Law or bias ECR plasma CVD method _{using, SiH 4 + O 2 + N} 2 mixed gas or SiH _4,,
An anti-reflection film made of a SiO _x N _y film was formed using a + N ₂ O mixed gas.

Embodiment 5 In this embodiment, an anti-reflection film made of a SiO _x N _y film is used.
An undersubstrate was processed in the same manner as in Example 1 except that a film was formed by the following method. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
Method, bias ECR plasma CVD method,
_An anti-reflection film made of a SiO _{x Ny} film was formed using a mixed gas of ₄ + O ₂ + N ₂ or a mixed gas of SiH ₄ + N ₂ O and Ar or N ₂ as a buffer gas.

Embodiment 6 In this embodiment, an anti-reflection film made of a SiO _x N _y film was used.
The base substrate was processed in the same manner as in Example 1 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N _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.

Embodiment 7 In this embodiment, an anti-reflection film made of a SiO _x N _y film is used.
The base substrate was processed in the same manner as in Example 1 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N _y
The etching of the film is performed 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 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 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 that time, in this embodiment, SiO _x N _{y is used} as the anti-reflection film.
Use a membrane.

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. Al-Si-Cu
For example, Si is about 1% by weight and Cu is preferably 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-SCu alloy.

As an antireflection film used on a low melting point metal base substrate such as Al, Al-Si, Al-Si-Cu, etc.
The method of finding the iO _x N _y film was performed in the same manner as in Example 1 except that the material of the base substrate and the reflectance were different. 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
In FIG. 28, the contour lines of the amount of light absorbed in the resist film with respect to changes in the optical constants n _art and k _art of the antireflection film are shown in FIG.
Shown in

(3) Resist film thickness 1000 nm, 101
As a result of repeating the above (2) for each of 8 nm and 1035 nm, the results are shown in FIGS. 29, 30, and 31, respectively. (4) result of determining a common region in Fig. _{28~31, n art = 4.8, k} art = 0.45 _{or, n art = 2.0, k art} = 0.8
I got That is, when the film thickness of the antireflection film is 30 nm, the conditions to be satisfied by the optimum antireflection film are _nart = 4.8, _kart = 0.45, or _nart = 2.0, _kart = 0. .8
It is.

When the standing wave effect was obtained using these conditions, the results shown in FIGS. 32 and 33 were obtained. 33 and 34, 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. Also, (2)
By repeating (4) to (4), the optimum condition of the antireflection film according to the thickness of the antireflection film is obtained. FIG. 22 shows the obtained result.
As shown in FIG. As shown in FIGS. 22 and 34, the solution (Val
ue) 1; as a reflection preventing film, a reflection refractive index n
Is not less than 1.2 and not more than 3.4, and the absorption refractive index k is 0.4
Not less than 1.4 and a film thickness of not less than 10 nm and not more than 100 nm.
The following are the optimal antireflection films, and the solution (Va
lue) 2, as an antireflection film, the reflection refractive index n is 1.9 or more and 5.7 or less, and the absorption refractive index k is 0.1 or less.
It has been found that those having a value of not less than 2 and not more than 0.62 are optimum antireflection films. Antireflection coatings having n and k matching the curves shown in FIGS. 22 and 34 are most preferred, but not necessarily on the curves, where n is ± 0.6, preferably ± 0.2 and k Is within the range of ± 0.3, preferably ± 0.2, more preferably 0.15, and still more preferably ± 0.05.

(6) It was examined using a spectroscopic ellipsometer (SOPRA) whether or not there was a kind of film that satisfies the conditions to be satisfied by the antireflection film obtained in (5) above. As a result, it has been found that the optical constant changes as shown in FIG. 35 according to the film forming conditions when forming the SiO _x N _y film by using the CVD method. The region indicated by a circle in FIG. 35 satisfies the conditions of FIGS. That is, preferably, the reflection refractive index n = 2.1 ± 0.6 and the absorption refractive index k
It is expected that the standing wave effect can be minimized if an SiO _x N _y film having a thickness of 0.7 ± 0.2 and a thickness d = 30 nm ± 10 nm is used as an antireflection film.

Next, the above optical conditions and the film thickness of SiO _x
Indeed standing wave effect by depositing N _y film was confirmed whether is reduced. As shown in FIG. 27, a low-melting-point metal material layer G such as Al, Al-Si, or Al-Si-Cu is laminated on a silicon substrate S. Then, an anti-reflection film ΔRL made of a SiO _x N _y film was formed. That is, using an ECR-CVD apparatus, the flow rate ratio of SiH ₄ / N ₂ O is 0.83,
An iO _x N _y film was formed to a thickness of about 25 nm. The SiO _x N _y
The reflection refractive index n of the antireflection film ARL made of a film is 2.08
And the absorption refractive index k was 0.85. The SiO
on the antireflection film ARL consisting _x N _y film, XP884
Example 8 in FIG. 36 shows the result of forming a photoresist PR made of No. 3 and examining the standing wave effect. 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 2.

In the eighth embodiment, the standing wave effect is about ± 0.5.
%, And the standing wave effect was reduced to about 1/60 as compared with the case of Comparative Example 2 in which the antireflection film was not used (± 30%). In the structure shown in FIG.
The R a line width of 0.35μm rule, lambda as an exposure light source
When photolithography was performed using a KrF laser of = 248 nm, 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, the etching of the SiO _x N _y film is performed using CHF ₃ (50 to 100 SCCM) +
Using a gas system of O ₂ (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 etching is preferable. 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.

Embodiment 9 In this embodiment, 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 shown in the eighth embodiment. Or, for n, the value on the curve ± 0.3, for k, the value on the curve ±
An anti-reflection film made of a SiO _x N _y film within a range of 0.3 was formed by the following method. That is, in this embodiment, the parallel plate type plasma CVD method and the ECR plasma C
VD method or bias ECR plasma CVD method, using microwave (2.45 GHz), SiH
₄ + O ₂ + N ₂ mixed gas or SiH ₄ + N ₂ O
Film formation was performed using a mixed gas. By adjusting the gas flow ratio by such a CVD method, the values on the curves in the diagrams (FIGS. 22 and 34) showing the relationship between the anti-reflection film thickness and the optical characteristics to be satisfied by the optimum anti-reflection film, Or
An anti-reflection film made of a SiO _x N _y film having a value of ± 0.3 on the curve for n and a value of ± 0.3 on k was successfully formed.

Embodiment 10 In this embodiment, 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 shown in the eighth embodiment. Or, for n, the value on the curve ± 0.3, for k, the value on the curve ±
An anti-reflection film made of a SiO _x N _y film within a range of 0.3 was formed by the following method. That is, in this embodiment, in the parallel plate type plasma CVD method, the ECR plasma C
VD method or bias ECR plasma CVD method, using microwave (2.45 GHz), SiH
₄ + O ₂ + N ₂ mixed gas or SiH ₄ + N ₂ O
A film was formed using a mixed gas and Ar or N ₂ as a buffer gas. By adjusting the gas flow ratio by such a CVD method, the values on the curves in the diagrams (FIGS. 22 and 34) showing the relationship between the anti-reflection film thickness and the optical characteristics to be satisfied by the optimum anti-reflection film, Alternatively, an antireflection film made of a SiO _{x Ny} film having a value of ± 0.3 on the curve and a value of ± 0.3 on the curve for k was successfully formed. .

Embodiment 11 In this embodiment, the values on the curves in FIGS. 22 and 34 showing the relationship between the antireflection film thickness and the optical characteristics to be satisfied by the optimum antireflection film shown in the eighth embodiment. Or, for n, the value on the curve ± 0.3, for k, the value on the curve ±
An anti-reflection film made of a SiO _x N _y film within a range of 0.3 was formed by the following method. That is, in this embodiment, in the parallel plate type plasma CVD method, the ECR plasma C
Using a VD method or a bias ECR plasma CVD method, a mixed gas of SiH ₄ + O ₂ + N ₂ or Si gas
A film was formed using a H ₄ + N ₂ O mixed gas. Such a C
By adjusting the gas flow ratio by the VD 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,
Alternatively, an antireflection film made of a SiO _{x Ny} film having a value of ± 0.3 on the curve for n and a value of 0.3 on the curve for k was successfully formed. .

Embodiment 12 In this embodiment, the relationship between the anti-reflection film thickness shown in Embodiment 8 and the optical characteristics to be satisfied by the optimum anti-reflection film (FIG. 2)
2, the value on the curve in FIG. 34), or for n, the value on the curve ± 0.3, for k, the value on the curve ±
An anti-reflection film made of a SiO _x N _y film within a range of 0.3 was formed by the following method. That is, in this embodiment, in the parallel plate type plasma CVD method, the ECR plasma C
Using a VD method or a bias ECR plasma CVD method, a mixed gas of SiH ₄ + O ₂ + N ₂ or Si gas
A film was formed using an H ₄ + N ₂ O mixed gas and Ar or N ₂ as a buffer gas. By adjusting the gas flow ratio by such a CVD method, the values on the curves in the diagrams (FIGS. 22 and 34) showing the relationship between the anti-reflection film thickness and the optical characteristics to be satisfied by the optimum anti-reflection film, Or
An anti-reflection film made of a SiO _x N _y film having a value of ± 0.3 on the curve for n and a value of 0.3 on the curve for k was successfully formed.

Example 13 In this example, an anti-reflection film made of a SiO _x N _y film was used.
The base substrate was processed in the same manner as in Example 8 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N
etching of the _y layer _is, C ₄ F 8 _(30~70SCCM)
+ CHF ₃ (10-30 SCCM) gas system and 2
A desired pattern was etched by a reactive etching method in which a power of about 100 to 1000 W was applied under a pressure of about Pa to increase ionicity.

Embodiment 14 In this embodiment, an anti-reflection film made of a SiO _x N _y film was used.
The base substrate was processed in the same manner as in Example 8 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N
_{The y-} 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 100.
A desired pattern was etched by a reactive etching method in which a power of about 0 W was applied to increase ionicity.

Embodiment 15 In this embodiment, as shown in FIG. 37, a silicon base substrate G such as monocrystalline silicon, polycrystalline silicon, amorphous silicon, and doped polysilicon is used as a base substrate S. An anti-reflection film ARL and a silicon oxide film Ox such as SiO _{2 as} necessary are stacked thereon, and the photoresist PR is subjected to photolithography using KrF excimer lithography. At this time, in this embodiment, a SiO _x N _y film is used as the antireflection film.

[0088] Single crystal silicon, polycrystalline silicon, amorphous silicon, as an anti-reflection film used for a silicon-based substrate, such as doped polysilicon, technique found SiO _x N _y film, the underlying substrate material and reflection The procedure was performed in the same manner as in Example 1 except that the ratios were different. 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. 38 shows the standing wave effect at this time. From FIG. 38, the standing wave effect is approximately ±
20%. (2) In FIG. 38, 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, the change in the amount of absorbed light in the resist film with respect to the change in the optical constants n _art and k _art of the antireflection film is determined. (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 operation determined for the thickness of the various anti-reflection film,
Thereby, the optimum value of the optical constant (n
Value, k value). For example, if the thickness of the anti-reflection film is 32
The optical conditions to be satisfied by the optimum antireflection film when nm is set are _nart = 2.0 and _kart = 0.55.

When the film thickness of the anti-reflection film is 100 nm, the optical conditions to be satisfied by the optimum anti-reflection film are n _art = 1.9 and k _art = 0.35. When the standing wave effect was obtained using the above two conditions, the results shown in FIGS. 39 and 40 were obtained. In FIGS. 39 and 40, the standing wave effect represented by the optimum value is extremely small, and in each case, the range is about 1% or less. The standing wave effect was reduced to about 1/20 or less as compared with the case without the antireflection film.

(5) The above operations (2) to (4) are performed when the thickness of the antireflection film is set to 32 nm and 100 nm.
By repeating (2) to (4), the optimum condition of the anti-reflection film according to the thickness of the anti-reflection film is obtained. For example, when the underlying substrate is made of polysilicon, amorphous silicon or doped silicon and the thickness of the antireflection film is 33 nm, the optical conditions to be satisfied by the optimal antireflection film are _nart = 2.01, k _art =
0.62. When the standing wave effect was obtained using the above conditions, the result shown in FIG. 41 was obtained. In FIG. 41, the standing wave effect indicated by the optimum value is extremely small, and the range is about 1% or less. The standing wave effect was reduced to about 1/20 or less as compared with the case without the antireflection film.

(6) Using a spectroscopic ellipsometer (SOPRA), an investigation was made to determine whether or not there was a film type satisfying the conditions to be satisfied by the antireflection film obtained in (5) above. As a result, it has been found that the optical constant changes as shown in FIG. 42 according to the film forming conditions when forming the SiO _x N _y film by using the CVD method. The area indicated by a circle in FIG. 42 satisfies the above condition (4).

That is, if the CVD conditions are set so as to be in the region indicated by the circle in FIG. 42 and the antireflection film made of the SiO _x N _y film is formed, the reflection refractive index n and the absorption refractive index k are obtained. is, _n art _{= 2.0} film thickness of the antireflection film is optimized in 32 nm, k art = 0.55, or the film thickness of the antireflection film is optimum at 100nm _n art = 1.
9, k _art = 0.35 or the thickness of the antireflection film is 3
_N art = 2.01 is optimal in the _{3nm, k art} =
It approaches 0.62. The allowable range of n is ± 0.6, k
Is ± 0.3, and the allowable range of the film thickness is ± 10 nm.

As a result, as shown in FIG. 37, on the undersubstrate G made of a silicon-based material,
Under the conditions of the mark, an anti-reflection film made of a SiO _x N _y film is formed, and a photoresist PR is formed thereon directly or through a silicon oxide film. , Standing wave effects can be minimized. Actually, in the structure shown in FIG. 37, 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 a 0.35 μm rule. A good resist pattern close to the pattern was obtained.

Thereafter, the underlying substrate was etched using the resist pattern as a mask. First, the etching of the _SiO x _{N y film, CHF 3 (50~100SCCM) + O} 2
Using a (3 to 20 SCCM) gas system, reactive etching (RIE) is performed under a pressure of about 2 Pa and a power of about 100 to 1000 W to increase the ionicity, and a desired pattern is formed. Was etched. Next, the surface of the underlying substrate G made of a silicon-based material shown in FIG. 37 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.

Embodiment 16 In this embodiment, the SiO _x N _y film shown in Embodiment 15 is used.
An anti-reflection film was formed in the same manner as in Example 15 except that the film was formed by the following method. That is, in the present embodiment, in the parallel plate type plasma CVD method, the ECR plasma CV
Method D, or by using a bias ECR plasma CVD method, a microwave (2.45 GHz), SiH ₄
A film was formed using a mixed gas of + O ₂ + N ₂ or a mixed gas of SiH ₄ + N ₂ O.

Embodiment 17 In this embodiment, the SiO _x N _y film shown in Embodiment 15 is used.
An anti-reflection film was formed in the same manner as in Example 15 except that the film was formed by the following method. That is, in the present embodiment, in the parallel plate type plasma CVD method, the ECR plasma CV
Method D, or by using a bias ECR plasma CVD method, a microwave (2.45 GHz), SiH ₄
A film was formed using a mixed gas of + O ₂ + N ₂ or a mixed gas of SiH ₄ + N ₂ O and Ar or N ₂ as a buffer gas.

Embodiment 18 In this embodiment, the SiO _x N _y film shown in Embodiment 15 is used.
An antireflection film was formed in the same manner as in Example 15 except that the film was formed by the following method. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
Or a mixed gas of SiH ₄ + O ₂ + N ₂ or SiH ₄ using a bias ECR plasma CVD method.
A film was formed using a + N ₂ O mixed gas.

Embodiment 19 In this embodiment, the SiO _x N _y film shown in Embodiment 15 is used.
An antireflection film was formed in the same manner as in Example 15 except that the film was formed by the following method. That is, in this embodiment,
Parallel plate plasma CVD, ECR plasma CVD
Gas or a mixed gas of SiH ₄ + O ₂ + N ₂ or a bias gas ECR plasma CVD method.
_A film was formed using a ₄ + N ₂ O mixed gas and Ar or N ₂ as a buffer gas. After the formation of the SiO _x N _y film, plasma treatment with O ₂ was performed.

Embodiment 20 In this embodiment, an anti-reflection film made of a SiO _x N _y film is used.
The base substrate was processed in the same manner as in Example 15 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N
etching of the _y layer _is, C ₄ F 8 _(30~70SCCM)
+ CHF ₃ (10-30 SCCM) gas system and 2
A desired pattern was etched by a reactive etching method in which a power of about 100 to 1000 W was applied under a pressure of about Pa to increase ionicity.

Embodiment 21 In this embodiment, an anti-reflection film made of a SiO _x N _y film was used.
The base substrate was processed in the same manner as in Example 15 except that etching was performed using the resist pattern as a mask by the following method. That is, in the present embodiment, SiO _x N
_{The y-} 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 100.
A desired pattern was etched by a reactive etching method in which a power of about 0 W was applied to increase ionicity.

Embodiment 22 In this embodiment, a mixed gas of SiH ₄ and N ₂ O is used
When an iO _x N _y film was formed, it was confirmed that the formed film contained hydrogen. That is, in the above embodiment, a portion of the _SiO x _{N y} film and thought have antireflection _film, SiO _x N y _{H z} films (where, z is 0 Any Good) is considered to have been. Figure 43 is a _SiH 4 / _{N 2} O flow ratio in film formation in the present embodiment, n of the formed _SiO x _{N y} film, shows the relationship between k value, in FIG. 44, similarly SiH ₄ / N ₂ O flow rate ratio and formed Si
The amount of each element of Si, O, N, and H in the O _x N _y film (ato
As shown in FIG. 44, there is a variation depending on the flow rate ratio of SiH ₄ / N ₂ O, but the formed SiO _{x Ny} film contains H, In fact, it can be seen that a film having the element composition of the SiO _x N _y H _z film is formed.

Qualitatively, as shown in the infrared absorption spectrum diagram (particularly, the FTIR diagram) shown in FIG. 45, the peak derived from the Si—O, Si—N bond was obtained at any flow rate ratio. In addition, there are peaks derived from N—H and Si—H bonds. The existence of such hydrogen is unknown, but it is thought that it may contribute to the antireflection function to some extent. When a hydrogen-containing gas is used as a source gas, hydrogen is generally considered to be contained in a film in some form. In particular, hydrogen is remarkable in plasma-based film forming means such as a plasma CVD method.

[0103] In this embodiment, a refractory metal silicide as a base substrate material W-Si, also with SiO ₂ of W-Si, and Al-1 wt% S is a metallic material
i, an anti-reflection film having various thicknesses is formed on the SiH ₄ / N ₂ O
A film is formed using a mixed gas system, and SiH ₄ / N that gives optimum k value and n value for i-line or excimer laser light
_The 2O flow rate ratio was determined from FIG. 43, and the resulting Si
O _x N _y H _z films of x, y, was examined z value, were as shown in the following Table 1.

[0104]

[Table 1]

In FIG. 44, the positions corresponding to each of the optimal conditions (1) to (4) are shown. According to this example, the wavelength of 150 nm was used as the anti-reflection film for W-Si .
In the range of _450nm, when using a SiO _x N y _{H z} film, x is the range of 0.30 to 0.80, y is 0.1
Preferably in the range of 0 to 0.30, z is zero,
That is, it may not contain hydrogen, but if it contains hydrogen,
It has been found that z is preferably in the range of 0.20 to 0.60.

As an anti-reflection film for Al—Si, SiO _x is used in the wavelength range of 150 to 450 nm.
When using a N _y H _z film, x is preferably in the range of 0.30 to 0.70, y is preferably in the range of 0.05 to 0.30, and z may be zero, that is, may not contain hydrogen. In the case of containing hydrogen, it is understood that z is preferably in the range of 0.1 to O05.

Further, as an anti-reflection film of an underlying substrate including W-Si , Al-Si and a silicon-based material,
When using a O _x N _y H _z films, from the results shown in FIG. 44, Si is preferably 30 to 55 atomic%, O is 20-4
0 atomic% is preferable, H is preferably 15 to 25 atomic%, and N is preferably 20 atomic% or less, more preferably 15 atomic% or less, and still more preferably 10 atomic% or less and 5 atomic% or more. From these results, when SiO _x N _y H _z is used as the antireflection film, x is 0.40
~ 1.30, y is 0.09 ~ 0.35, z is 0.25 ~
It is preferably in the range of 0.85. In addition, SiO _x
As shown in FIG. 46, a general flow rate ratio used for forming a _Ny film is such that SiH ₄ / N ₂ O is 0.2 to 2.0.
Range.

Next, on a base substrate made of W-Si ,
The results of examining the standing wave effect of a photoresist by forming an anti-reflection film made of a SiO _x N _y H _z film are shown. Specifically, at the exposure wavelength of KrF, n = 1.93, k =
On a base substrate made of 2.73 W-Si , SiO _x
An anti-reflection film made of N _y H _z is obtained by n = 2.12 and k =
A film thickness of 29 nm is formed by a plasma CVD method at a flow ratio determined from the graph shown in FIG. 43 so as to approach 0.54, and a silicon oxide film of n = 1.52 and k = 0 is formed thereon by 170 nm. And n = 1.8 on top of it.
A photoresist having 0 and k = 0.011 was formed.

The simulation result of the standing wave effect in this case is shown by with ARL in FIG. For comparison, the result of similarly obtaining the standing wave effect except that the anti-reflection film was not provided is shown in FIG.
Indicated by ARL. According to this example, it was confirmed that the standing wave effect could be almost completely eliminated.

In practice, using the exposure wavelength of KrF, W-
As a result of performing photolithography processing of the photoresist on the base substrate made of Si using the antireflection film under the above conditions according to the rule of 0.35 μm, a good fine pattern was formed.

Embodiment 23 As shown in FIG. 48, on an underlying substrate G made of W-Si , at an exposure wavelength of KrF, n = 1.52 and k = 0.
A silicon oxide film Ox of a thickness of 170 nm,
_Thereon, an antireflection film made of SiO _x N y _{H z,} n
= 2.1, k = 0.6, and a film thickness d = 29 nm by a plasma CVD method at a flow ratio determined from the graph shown in FIG. k =
A photoresist of 0.01 was deposited.

The simulation result of the standing wave effect in that case is equivalent to the with ARL in FIG. 47, and is compared with the result obtained in the same manner as the standing wave effect except that the antireflection film is not provided. It was confirmed that the standing wave effect could be almost completely eliminated. Actually, using the exposure wavelength of KrF, the photoresist was subjected to photolithography processing on the underlying substrate made of W-Si using the antireflection film under the above conditions using the 0.35 μm rule, and as a result a good fine pattern was obtained. Was formed.

Example 24 An anti-reflection film made of SiO _x N _y H _z was formed on an underlying substrate made of W-Si at an exposure wavelength of i-line by n =
The plasma CV is obtained at a flow ratio determined from the graph shown in FIG. 43 so as to approach 1.8 to 3.0 and k = 0.5 to 0.9.
A film is formed at a film thickness d = 25 ± 10 nm by the method D, and n = 1.7, k before exposure (transmittance 10% / umt).
= 0.06, n = after exposure (transmittance 95% / umt)
A photoresist having a thickness of 1.7 and k = 0.0015 was formed.

The simulation result of the standing wave effect in that case is equivalent to the with ARL in FIG. 47, and is compared with the result obtained in the same manner as the standing wave effect except that the antireflection film is not provided. It was confirmed that the standing wave effect could be almost completely eliminated. Actually, a photolithography process of a photoresist was performed on an underlying substrate made of W-Si using an antireflection film under the above conditions using an exposure wavelength of i-line and a 0.35 μm rule. A pattern was formed.

Example 25 An anti-reflection film made of SiO _x N _y H _z was formed on an undersubstrate made of single crystal silicon at an exposure wavelength of KrF so that n = 2.0 and k = 0.55. In FIG. 43, a film is formed with a film thickness d = 32 nm by a plasma CVD method at a flow rate ratio obtained from the graph shown in FIG. 43, and n = 1.8 thereon.
A photoresist having 0 and k = 0.011 was formed. In this case, the optimal optical constant and film thickness of the antireflection film made of SiO _x N _y H _z are n = 1.9, k = 0.35, and d =
It may be 100 nm. The simulation result of the standing wave effect in that case is equivalent to the with ARL in FIG. 47, and is compared with the result obtained in the same manner as the standing wave effect except that the antireflection film is not provided. It was confirmed that the effect could be almost completely eliminated. In fact, KrF
A photolithography process of a photoresist was performed on a base substrate made of single-crystal silicon using the antireflection film under the above conditions using the exposure wavelength of 0.35 μm, and as a result, a good fine pattern was formed. .

Example 26 After forming an anti-reflection film made of a SiO _x N _y H _z film,
Example 2 except that the surface was treated with O ₂ plasma.
Photolithography processing of the photoresist was performed in the same manner as in 3, 24, or 25 according to the 0.35 μm rule. As a result, a favorable fine pattern could be formed.
By performing the O ₂ plasma treatment, deactivation of the acid below the chemically amplified resist can be prevented, and footing or overhang of the pattern edge portion of the resist can be prevented.

Example 27 An antireflection film made of SiO _x N _y H _z was exposed on a base substrate made of Al—Si at an exposure wavelength of KrF by n.
= 2.09, k = 0.87, a film thickness of 24 nm was formed by the plasma CVD method at a flow ratio determined from the graph shown in FIG. 43, and n = 1.80, k =
A 0.011 photoresist was deposited.

A simulation result of the standing wave effect in this case is shown as with ARL in FIG. For the sake of comparison, the result of obtaining the standing wave effect in the same manner except that the antireflection film was not provided is shown in FIG.
ut ARL. According to this example, it was confirmed that the standing wave effect could be almost completely eliminated. Actually, using an exposure wavelength of KrF, an anti-reflection film under the above conditions was used on an underlying substrate made of Al-Si to form 0.35 μm.
As a result of performing photolithography processing of the photoresist according to the m rule, a favorable fine pattern was formed.

Example 28 At the exposure wavelength of the i-line, n = 3.067 and k = 2.7.
On the base substrate made of a 93 W-Si, _SiO x _{N y}
The anti-reflection film made of _{H z, n = 2.58, k} = 0.4
A film was formed to a thickness of 30 nm by a plasma CVD method at a flow ratio determined from the graph shown in FIG.
A naphthokimenediazide-based photoresist having n = 1.693 and k = 0.032 was formed thereon.

The photoresist was exposed using an i-line so as to form a 0.44 μm line and space (L / S) pattern, and the antireflection effect was measured. The results are shown by with ARL in FIG. In addition,
For comparison, the result of measuring the antireflection effect in the same manner except that the antireflection film was not used is shown in FIG.
hout ARL. From this figure, the effect of the antireflection film in this embodiment can be understood.

Similarly, the simulation results are shown in FIG. 51 (a graph relating to i-line and absorptivity on W-Si ) and FIG. 52 (a graph relating to i-line and reflectivity on W-Si ). As shown in these figures, in this embodiment, an excellent antireflection effect can be obtained in both cases of the reflectance and the absorptance.

FIGS. 53 and 54 show the relationship between the resist thickness and the critical dimension. In each case, experiments were performed on W-Si using KrF excimer laser light. FIG. 53 shows a case of a 0.30 μm line and space pattern, and FIG.
This is the case of a 5 μm line and space pattern. In each case, a chemically amplified positive resist was used as the resist.

Embodiment 29 As described above, as an antireflection film for excimer laser light, for example, on a refractory metal silicide, a material in which n is around 2.4 and k is around 0.7 is suitable. An SiO _x N _y film or a SiO _x N _y H _z film is effective as an antireflection film. Further, n having these antireflection effects
In order to form a SiO _x N _y film or a SiO _x N _y H _z film having the following formulas, k and n can be changed by changing the composition ratio (x, y) of these films. Although it is conceivable, it is not always easy to form a film having the desired n and k by controlling the composition ratio with good controllability.

In this embodiment, the desired n as the antireflection film
In order to form a film having と and k, an antireflection film is formed by using a material containing at least a Si element and a material containing at least an O element as source gases. In this embodiment, the material containing at least Si is SiH ₄
By using N ₂ O as a substance containing at least O and controlling the optical constant of the film using a gas flow ratio of SiH ₄ and N ₂ O as a parameter, a film having a desired antireflection effect can be obtained. Formed. The optical constant of the film when the gas flow ratio of SiH ₄ and N ₂ O is changed using a parallel plate plasma CVD apparatus changes as shown in FIG. For example, the following conditions may be used as one of the film forming conditions suitable for excimerography. SiH ₄ = 50 sccm N ₂ O = 50 sccm RF Power = 190 W Pressure = 332.5 pa (2.5 torr) Substrate temperature = 400 ° C. Distance between electrodes = 1 cm

Here, 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 also be controlled by using the deposition pressure, RF power, and substrate temperature as parameters.

[0126]

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 illustrating 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 _art and k _art 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 illustrating a locus (contour of absorption light amount) of a change in absorption light amount of the resist film with respect to a change in n _art and k _art 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.

FIG. 24 is a diagram showing a behavior of SiO _x N _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.

FIG. 26 is a diagram showing an anti-reflection effect of SiO _x N _y (25 nm) on W-Si.

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

28 is a diagram illustrating the case of a film thickness 30nm of antireflection film, _n art for resist film thickness 982 _nm, the locus of the change in the amount of light absorbed in the resist film relative to variation of _{k art} (the contour of the amount of light absorbed).

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 illustrating optical constant characteristics depending on film formation conditions of a SiO _x N _y film.

FIG. 36 is a diagram showing a standing wave effect under optimum conditions in another embodiment.

FIG. 37 is a cross-sectional view showing a film formation structure of an antireflection film in another example.

FIG. 38 is a diagram showing a standing wave effect.

FIG. 39 is a diagram showing an antireflection effect of a SiO _x N _y film (32 nm) on Si.

FIG. 40 is a diagram showing an anti-reflection effect of a SiO _x N _y film (100 nm) on Si.

FIG. 41 shows a SiO _x N _y film (33n) on polysilicon.
It is a figure which shows the antireflection effect of m).

FIG. 42 is a diagram showing a characteristic change of an optical constant depending on a film forming condition of a SiO _x N _y film.

FIG. 43: SiH ₄ / N ₂ O flow ratio and Si formed
FIG. 4 is a diagram showing a relationship between an O _x N _y film (or a SiO _x N _y H _z film) and n and k values.

FIG. 44: SiH ₄ / N ₂ O flow ratio and formed Si
O _x N _y film (or _SiO x _N y _{H z} films) in Si,
It is a figure which shows the relationship with O, N, and H amount (RBS).

FIG. 45 is an IR absorption spectrum diagram of the antireflection film formed in the example.

FIG. 46 is a view showing a generally used flow rate ratio range of SiH ₄ / N ₂ O.

FIG. 47 is a diagram showing an antireflection effect in the example.

FIG. 48 is a view showing a film formation structure of an antireflection film in another example.

FIG. 49 is a diagram showing an antireflection effect in another embodiment.

FIG. 50 is a diagram showing an antireflection effect in another embodiment.

FIG. 51 is a diagram showing a simulation result (related to an absorptivity) of an antireflection effect in the embodiment shown in FIG.

FIG. 52 is a diagram showing a simulation result (in terms of reflectance) of an antireflection effect in the embodiment shown in FIG. 50;

FIG. 53 is an operation explanatory view of another example (0.30 μmL / S).

FIG. 54 is an operation explanatory view of another example (0.35 μmL / 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. Hei 4-316073 (32) Priority Japan, Japan (JP) Application for accelerated examination (56) References JP-A-60-153125 (JP, A) JP-A-59-6540 (JP, A) 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 (57)

(57) [Claims] 1. A semiconductor device comprising a plurality of layers,
At least silicon, oxygen and nitrogen formed on the ground substrate
On the anti-reflective coating composed of silicon oxide based film containing
And then expose the photoresist with a single wavelength
A resist pattern forming method for forming a pattern.
An anti-reflection film composed of the silicon nitride oxide-based film,
Depending on the type of the underlying substrate, the photoresist at the time of exposure
Of standing wave effect due to fluctuation of resist film thickness at high temperature
The refractive index of the antireflection film under the condition that the minimum value is obtained.
n, absorption refractive index k, and film thickness.
A resist pattern having a process of forming a film while adjusting
Forming method. 2. The method according to claim 2, wherein the surface of the undersubstrate is made of a silicon-based material.
2. The method according to claim 1, wherein the resist pattern is formed. 3. The silicon-based material is a single crystal silicon,
Polycrystalline silicon, amorphous silicon, doped polysilico
3. The method for forming a resist pattern according to claim 2 , which is one of the following: 4. The undersubstrate has a surface having a high melting point metal or
2. The method for forming a resist pattern according to claim 1, wherein the method is formed of a refractory metal silicide-based material . 5. The method according to claim 1, wherein the refractory metal is tungsten.
The refractory metal silicide-based material is tungsten silicide.
The method for forming a resist pattern according to claim 4, wherein the resist pattern is an id . 6. The undersubstrate has a surface having a low melting point metal material.
The method for forming a resist pattern according to claim 1, wherein: 7. The low melting point metal-based material is aluminum,
Aluminum-silicon alloy, aluminum-silicon
7. The method for forming a resist pattern according to claim 6, wherein the method is any one of copper alloy, copper, and copper alloy . 8. A semiconductor device comprising multiple layers,
At least silicon, oxygen, nitrogen and
Antireflection composed of silicon oxynitride film containing hydrogen
The photoresist is exposed on the film with a single wavelength and
Resist pattern forming method for forming a strike pattern.
Thus, an antireflection film composed of the silicon nitride oxide-based film,
Depending on the type of the underlying substrate, the photoresist at the time of exposure
Of standing wave effect due to fluctuation of resist film thickness at high temperature
The refractive index of the antireflection film under the condition that the minimum value is obtained.
n, absorption refractive index k, and film thickness.
A method for forming a resist pattern , comprising a step of forming a film while adjusting . 9. The method according to claim 9, wherein the surface of the undersubstrate is made of a silicon-based material.
9. The method for forming a resist pattern according to claim 8, wherein the method is performed. 10. The silicon-based material is a single-crystal silicon.
, Polycrystalline silicon, amorphous silicon, doped policy
10. The method for forming a resist pattern according to claim 9, wherein the method is any one of recon . 11. The undersubstrate has a surface having a high melting point metal or
9. The method for forming a resist pattern according to claim 8 , wherein said material is made of a high melting point metal silicide-based material . 12. The high melting point metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
The method for forming a resist pattern according to claim 11 , wherein the side is a side . 13. The undersubstrate has a surface having a low melting point metal material.
9. The method for forming a resist pattern according to claim 8, wherein the resist pattern is formed of a material. 14. The low melting point metal-based material may be aluminum
Aluminum, silicon-alloy, aluminum-silicon
14. The method for forming a resist pattern according to claim 13, wherein the resist pattern is one of a con-copper alloy, copper, and a copper alloy . 15. A semiconductor device comprising a plurality of layers,
SiO _x N _y H _z formed on the base substrate (where x is
0.40 to 1.30, y is 0.09 to 0.35, z is 0
０．８0.85. Silicon nitride oxide represented by)
Photoresist on the anti-reflective coating
Is exposed by a single wavelength to form a resist pattern
A method of forming a resist pattern, comprising: forming an antireflection film made of the silicon nitride oxide-based film,
Depending on the type of the underlying substrate, the photoresist at the time of exposure
Of standing wave effect due to fluctuation of resist film thickness at high temperature
The refractive index of the antireflection film under the condition that the minimum value is obtained.
n, absorption refractive index k, and film thickness.
A resist pattern having a process of forming a film while adjusting
Forming method. 16. The surface of the undersubstrate is made of a silicon-based material.
The method for forming a resist pattern according to claim 15, wherein the method is configured. 17. The silicon-based material is a single-crystal silicon.
, Polycrystalline silicon, amorphous silicon, doped policy
17. The method for forming a resist pattern according to claim 16, wherein the method is any of recon . 18. The undersubstrate has a surface having a high melting point metal or
The method according to claim 15, wherein the resist pattern is made of a refractory metal silicide-based material . 19. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
19. The method for forming a resist pattern according to claim 18 , wherein the side is a side . 20. The undersubstrate has a surface having a low melting point metal material.
The method for forming a resist pattern according to claim 15, wherein the method is formed of a material. 21. The low-melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
21. The method for forming a resist pattern according to claim 20, wherein the method is any one of a con-copper alloy, copper, and a copper alloy . 22. The surface of the undersubstrate is made of a high melting point metal or
In the case of a refractory metal silicide-based material, the antireflection film has a reflection refractive index n of 1.0 or more and 3.6 or less.
And the absorption refractive index k is 0.11 or more and 0.75 or less.
Yes, SiO _x N with a film thickness of 10 nm or more and 100 nm or less
_y H _z (wherein, x is from .40 to 1.30, y is 0.0
9 to 0.35, z is in the range of 0 to 0.85. )
-Reflection film composed of silicon nitride oxide film to be formed
In a method for forming a resist pattern according to claim 15, wherein. 23. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
23. The method for forming a resist pattern according to claim 22 , which is a side . 24. The method according to claim 24, wherein the surface of the undersubstrate is made of a high melting point metal or
In no event the refractory metal silicide-based material, wherein the antireflection film, the reflection refractive index n of 1.7 or more 5.9 or more
Below, the absorption refractive index k is a positive number of 0.51 or less,
SiO _x N _y H _{z having a} film thickness of 25 nm or more and 100 nm or less
(Where x is 0.40 to 1.30 and y is 0.09 to
0.35 and z are in the range of 0 to 0.85. )
Anti-reflective coating composed of a silicon nitride oxide film
That, the resist pattern forming method according to claim 15, wherein. 25. The refractory metal is tungsten,
The refractory metal silicide-based material is tungsten silicide.
25. The method for forming a resist pattern according to claim 24 , wherein the side is a side . 26. A base material having a low melting point metal-based material.
In the above case, the antireflection film has a reflection refractive index n of 1.3 or more and 3.6 or less.
And the absorption refractive index k is 0.2 or more and 1.5 or less.
SiO _x N _y H having a film thickness of 10 nm or more and 70 nm or less.
_z (where x is 0.40 to 1.30, y is 0.09 to
0.35 and z are in the range of 0 to 0.85. )
16. The method for forming a resist pattern according to claim 15, wherein the method is an antireflection film composed of a silicon nitride oxide film . 27. The low melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
27. The method for forming a resist pattern according to claim 26, wherein the method is any one of a con-copper alloy, copper, and a copper alloy . 28. The undersubstrate having a low melting point metal-based material
In the above case, the antireflection film has a reflection refractive index n of 1.9 or more and 5.9 or less.
And the absorption refractive index k is 0.2 or more and 0.75 or less.
SiO _x N _y H having a thickness of 25 nm or more and 90 nm or less.
_z (where x is 0.40 to 1.30, y is 0.09 to
0.35 and z are in the range of 0 to 0.85. )
16. The method for forming a resist pattern according to claim 15, wherein the method is an antireflection film composed of a silicon nitride oxide film . 29. The low melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
29. The method for forming a resist pattern according to claim 28, wherein the method is any one of a con-copper alloy, copper, and a copper alloy . 30. A method according to claim 30, wherein the surface of said base substrate is made of
In this case, the antireflection film has a reflection refractive index n of 1.8 or more and 2.6 or less.
And the absorption refractive index k is 0.1 or more and 0.8 or less.
SiO _x N _y having a thickness of 20 nm or more and 150 nm or less.
H _z (wherein, x is from .40 to 1.30, y is 0.09
０．３0.35 and z are in the range of 0０〜0.85. )
Anti-reflection film composed of a silicon nitride oxide film
That, the resist pattern forming method according to claim 15, wherein. 31. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
31. The method for forming a resist pattern according to claim 30, wherein the method is any of recon . 32. A high melting point metal or high melting point metal silicide surface.
Directly or on the underlying substrate made of a side material
An anti-reflection film provided with a layer having an exposure wavelength of 150 to 450 nm.
The refractive index n is 1.0 or more and 3.6 or less,
The ratio k is 0.11 or more and 0.75 or less, and the film thickness is 10 nm or more.
100 nm or less, due to fluctuations in the thickness of the resist film
SiO _x that minimizes the dispersion of the standing wave effect
N _y H _z (where x is 0.40 to 1.30 and y is 0.
09 to 0.35 and z are in the range of 0 to 0.85. )so
An anti-reflection film made of the silicon nitride oxide film represented . 33. The refractory metal is tungsten,
The refractory metal silicide is tungsten silicide.
There, the anti-reflection film of claim 32. 34. A surface having a high melting point metal or a high melting point metal silicide.
Directly or on the underlying substrate made of a side material
An anti-reflection film provided with a layer having an exposure wavelength of 150 to 450 nm.
And the refractive index n is 1.7 or more and 5.9 or less,
The ratio k is a positive number of 0.51 or less, and the film thickness is 25 nm or more.
100 nm or less, due to fluctuations in the thickness of the resist film
SiO _x that minimizes the dispersion of the standing wave effect
N _y H _z (where x is 0.40 to 1.30 and y is 0.
09 to 0.35 and z are in the range of 0 to 0.85. )so
Composed of a silicon nitride oxide film represented by 35. The refractory metal is tungsten,
The refractory metal silicide is tungsten silicide.
There, the anti-reflection film of claim 34. 36. A base material whose surface is made of a low-melting metal material
Reflection provided directly or through other layers on the plate
An anti- reflection film , wherein the anti-reflection 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 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, the resist film or the resist film and the
Variation of standing wave effect due to variation in thickness of underlying light transmitting film
SiO _x N _y H _z (here,
Where x is 0.40 to 1.30 and y is 0.09 to 0.3
5, z is in the range of 0 to 0.85. )
An anti-reflection film made of a silicon oxide film. 37. The low melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
The antireflection film according to claim 36, wherein the antireflection film is any one of a con-copper alloy, copper, and a copper alloy . 38. A base material whose surface is made of a low melting point metal-based material.
Reflection provided directly or through other layers on the plate
An anti- reflection film , wherein the anti-reflection 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 20 nm.
Not less than 90 nm and a resist film or a resist film
Wave effect due to the variation of the thickness of the light-transmitting film and its underlying layer
SiO _x N _y H _z that minimizes the variation of the fruits
(Where x is 0.40 to 1.30 and y is 0.09 to
0.35 and z are in the range of 0 to 0.85. )
An anti-reflection film made of a silicon nitride oxide film. 39. The low melting point metal-based material may be aluminum
Aluminum, silicon-alloy, aluminum-silicon
The anti-reflection film according to claim 38, wherein the anti-reflection film is any one of a con-copper alloy, copper, and a copper alloy . 40. An undersubstrate whose surface is made of a silicon-based material
Anti-reflective coating, directly or through other layers
An anti-reflection coating , wherein the anti-reflection coating 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
SiO _x N _y that minimizes the variation of the wave effect
H _z (wherein, x is from .40 to 1.30, y is 0.09
０．３0.35 and z are in the range of 0０〜0.85. )
Anti-reflection film composed of a silicon nitride oxide film. 41. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
41. The anti-reflection film according to claim 40 , which is any of Recon . 42. 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.
A base substrate made of , and exposed directly or through another layer on the base substrate.
When the wavelength is 150 to 450 nm, the reflection refractive index n is
1.0 or more and 3.6 or less, absorption refractive index k is 0.11 or more
0.75 or less, and the film thickness is 10 nm or more and 100 nm or less.
Of the standing wave effect due to fluctuations in the resist film thickness
SiO _x N _y H _z (where,
x is 0.40 to 1.30, y is 0.09 to 0.35, z
Is in the range of 0 to 0.85. )
A semiconductor device having an antireflection film made of a recon film . 43. The refractory metal is tungsten,
The refractory metal silicide is tungsten silicide.
There, a semiconductor device according to claim 42, wherein. 44. 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.
A base substrate made of , and exposed directly or through another layer on the base 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.
It is a positive number and the film thickness is 25 nm or more and 100 nm or less.
Of the standing wave effect due to fluctuations in the resist film thickness
SiO _x N _y H _z (where,
x is 0.40 to 1.30, y is 0.09 to 0.35, z
Is in the range of 0 to 0.85. )
A semiconductor device having an antireflection film made of a recon film . 45. The refractory metal is tungsten,
The refractory metal silicide is tungsten silicide
There semiconductor device according to claim 44. 46. A semiconductor device comprising a plurality of layers, comprising a base substrate having a surface made of a low-melting metal 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
1.3 or more and 3.6 or less, and the absorption refractive index k is 0.2 or more.
5 or less, and the film thickness is 10 nm or more and 70 nm or less.
Of the standing wave effect due to fluctuations in the resist film thickness
SiO _x N _y H _z (where,
x is 0.40 to 1.30, y is 0.09 to 0.35, z
Is in the range of 0 to 0.85. )
A semiconductor device having an antireflection film made of a recon film . 47. The low-melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
47. The semiconductor device according to claim 46, wherein the semiconductor device is one of a con-copper alloy, copper, and a copper alloy . 48. A semiconductor device comprising a plurality of layers, comprising : a base substrate having a surface made of a low-melting-point metal-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
1.9 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.
Of the standing wave effect due to variations in the thickness of the resist film
SiO _x N _y H _z (where,
x is 0.40 to 1.30, y is 0.09 to 0.35, z
Is in the range of 0 to 0.85. )
A semiconductor device having an antireflection film made of a recon film . 49. The low melting point metal-based material is aluminum
Aluminum, silicon-alloy, aluminum-silicon
49. The semiconductor device according to claim 48, wherein the semiconductor device is one of a con-copper alloy, copper, and a copper alloy . 50. 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 to 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
SiO _x N _y H _z (where x is a small value)
0.40 to 1.30, y is 0.09 to 0.35, z is 0
０．８0.85. Silicon nitride oxide represented by)
A semiconductor device having an anti-reflection film made of a metal film . 51. The silicon-based material is a single crystal silicon
, Polycrystalline silicon, amorphous silicon, doped policy
The semiconductor device according to claim 50 , which is one of a recon . 52. Before the anti-reflection film is actually formed, a photoresist is required at the time of exposure according to the type of the base substrate.
Of the anti-reflective coating under conditions that minimize the standing wave effect
Simulation of refractive index n, absorption refractive index k and film thickness
And the reflection refractive index n and
Immediately on the surface of the underlying substrate so as to approach the absorption refractive index k.
Or through another layer, an oxide silicon containing at least nitrogen.
Adjusting film formation conditions for anti-reflection film composed of recon-based film
While the film thickness obtained by the simulation
2. The resist pattern according to claim 1, wherein the resist pattern is formed with an equal thickness.
Forming method. 53. At least a silicon atom and an oxygen atom
Vapor-phase growth using a substance containing
When the antireflection film is formed,
Content ratio of silicon and oxygen atoms (Si / O)
53. The method of forming a resist pattern according to claim 52 , wherein the value is 0.4 or more and 3 or less . 54. SiH ₄ and N ₂ as the source gas
The antireflection film is formed by a vapor deposition method using O.
When the gas flow ratio of SiH ₄ and N ₂ O (Si
H ₄ / _N 2 O) is 0.4 to 3, claim 5
3. The method for forming a resist pattern according to 2. 55. Before actually forming the anti-reflection film , a photoresist is required at the time of exposure depending on the type of the base substrate.
Of the anti-reflective coating under conditions that minimize the standing wave effect
Simulation of refractive index n, absorption refractive index k and film thickness
And the reflection refractive index n and
Immediately on the surface of the underlying substrate so as to approach the absorption refractive index k.
Or at least nitrogen and hydrogen through other layers
An anti-reflection film composed of a silicon oxide-based film containing
While adjusting the gas flow ratio,
9. The film is formed with a film thickness substantially equal to the film thickness obtained from the above.
Resist pattern forming method. 56. At least a silicon atom and an oxygen atom
Vapor-phase growth using a substance containing
When the antireflection film is formed,
Content ratio of silicon and oxygen atoms (Si / O)
55. The method for forming a resist pattern according to claim 55 , wherein the value is 0.4 or more and 3 or less . 57. SiH ₄ and N ₂ as the source gas
The antireflection film is formed by a vapor deposition method using O.
When the gas flow ratio of SiH ₄ and N ₂ O (Si
H ₄ / _N 2 O) is 0.4 to 3, a resist pattern forming method according to claim 55, wherein.