JPH08327539A - Method and device for judging quantity of absorbent inorganic antireflection film and film formation judging device - Google Patents

Abstract

PURPOSE: To judge film quality with accuracy by judging, from a specified value from which the state of film quantity as measured through the application of electromagnetic waves is known, the standing-wave reducing effect of an absorbent inorganic antireflection film when photolithography is performed while the absorbent inorganic antireflection film is actually laminated with a resist. CONSTITUTION: A wavelength range which a film does not absorb is determined in advance by means of a spectral or other ellipsometer and the like. In the wavelength range where absorption does not occur, the film thickness is measured by use of the spectral ellipsometer or other ellipsometers which can be set to those wavelengths. A refractive index, calculated by use of the wavelength at which sensitivity based on the film quantity is greatest and the intensity of the spectral ellipsometer is high, is made to coincide with a spectral refractive index using a database registering the latter, to calculate the spectral refractive index curve of the absorbent inorganic antireflection film measured. An amplitude chart of standing waves at each base is prepared in advance as a database, the amplitude chart and a desired axis are inputted, and from the acceptable and unacceptable areas of the amplitude the area of the database amplitude chart to which the spectral refractive index corresponds is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film quality determination method, a film quality determination apparatus, and a film formation apparatus and a film deposition apparatus in combination for the purpose of controlling the film quality when an inorganic film is used as an antireflection film for photolithography. Regarding a determination device.

[0002]

2. Description of the Related Art In photolithography, fluctuations in line width are a serious problem when forming fine patterns. In recent years, fluctuations in line width have increased as design rules shrink. The factors that cause the line width to vary include the steps of the underlying substrate, the sparseness and denseness of the pattern, and the like.

With the reduction of design rules, the exposure wavelength in photolithography is changed from g-line (436 nm) to i-line.
Line (365 nm), and KrF excimer laser (24
The wavelength has been shortened to 8 nm). The effect of multiple interference inside the resist as shown in FIG. 13 is increased by shortening the exposure wavelength. This is because the cycle of multiple interference becomes small and the substrate reflectance becomes high. Since the influence of such multiple interference becomes large, the fluctuation of the line width when the resist film thickness changes becomes large as shown in FIG. As a result, the resist film thickness changes due to the step of the underlying substrate, and the line width varies.

As one of the techniques for suppressing the line width variation of such a pattern, there is an antireflection technique as shown in FIG. This is because by arranging an absorbing organic film or inorganic film on the upper or lower part of the resist, the amount of light absorbed inside the resist when the resist film thickness is changed by absorption and phase cancellation is made constant, and the line width Is a method of suppressing the fluctuation of.

As an antireflection technique, as shown in FIG. 15 (A), a transparent organic antireflection film is laminated on the upper part of the resist to cancel the phase of the material (having a refractive index n = 1.3). Therefore, there is a method of keeping the amount of light absorbed in the resist constant. Further, when a high reflection substrate is used, as shown in FIG.
As shown in (B), there is a method of forming an absorptive antireflection film under the resist, and this method is advantageous in terms of line width change and halation because the amount of light traveling in various directions at a step or the like becomes small. Is.

In recent years, an inorganic antireflection film formed by the CVD or sputtering method has been used as an absorptive antireflection film for a high reflection substrate. As typical examples of the absorptive inorganic antireflection film, a SiO _x N _y : H film or a Si _N H _w : H film proposed by the present inventors (see Japanese Patent Application No. 4-359750) or hydrogen is used. There is an amorphous carbon film (aC: H film) containing. This aC: H film is described in, for example, the proceedings of the 40th Joint Lecture in Applied Physics, 559.

Such an absorptive inorganic antireflection film has a CV
Since the film is formed by using the D or sputtering method, there is a characteristic that the refractive index of the film changes when the plasma or the like changes. On the other hand, for the absorptive inorganic antireflection film, for example, a SiO _x N _y : H film is used, the refractive index of the film can be widely changed as shown in FIG. 16 by changing the film forming conditions. (The real part of the complex refractive index (Fig. 16
(A) and the imaginary part (FIG. 16B), this feature is used to prevent reflection. The SiO _x N _y : H film is shown in FIG.
As shown in, by changing the film formation ratio of the raw materials SiH ₄ and N ₂ O, n does not change, but k changes significantly (n is the real part of the complex refractive index, k is the complex refractive index). There is an imaginary part of the ratio), and the condition is optimized with k and the film thickness to prevent reflection. If optimized, as shown in FIG. 18, it can be determined by simulation (FIGS. 18 (a) and 18 (b)) with respect to an underlying substrate such as WSi or Al—Si or by actual measurement (FIG. 18 (c)). The effect of standing waves can be eliminated, and only the bulk effect due to the film thickness remains. As described above, the inorganic antireflection film has an excellent function that the standing wave can be made zero by controlling the refractive index.

[0008]

However, since the inorganic antireflection film is formed by physical vapor deposition (PVD) such as chemical vapor deposition (CVD) or sputtering, it depends on the state of film formation. The film quality may change and the refractive index may change. Therefore, it is possible to quickly and accurately determine whether or not the formed inorganic reflective film has a predetermined film quality and can reliably reduce or remove the influence of standing waves, and manage the film quality. Although demanded, up to now, the method and apparatus for monitoring the film formation state have not been established.

The present invention has been made in view of the above demands, and can accurately and promptly determine the film quality when it is applied to the photolithography of the absorptive inorganic antireflection film formed by the above-mentioned CVD or PVD. It is an object of the present invention to provide a film quality determination method for an absorptive inorganic antireflection film, a film quality determination device, and a film deposition determination device capable of monitoring a film deposition state.

[0010]

In order to achieve the above object, the present invention provides the following method for determining the film quality of an absorptive inorganic antireflection film, a film quality determining apparatus and a film forming determining apparatus. (1) A method for determining the film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, which comprises irradiating an electromagnetic wave to the absorptive inorganic antireflection film formed on the base substrate. By measuring a specific value for knowing the film quality state, the specific value of the absorptive inorganic antireflection film when a resist is actually laminated on the absorptive inorganic antireflection film and photolithography is performed from the specific value is measured. A method for determining a film quality of an absorptive inorganic antireflection film, which comprises determining a standing wave reducing effect. (2) A method for determining the quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, which comprises irradiating light onto the absorptive inorganic antireflection film formed on the base substrate to absorb the light. Of the refractive index at a wavelength different from the exposure wavelength for actually performing photolithography and the value of the refractive index obtained above, and the spectral refractive index prepared in advance are made to correspond to each other. Obtain the spectral refractive index curve and perform photolithography from the obtained spectral refractive index curve. Determine the value of the refractive index of the absorptive inorganic antireflective film at the exposure wavelength for photolithography, and obtain the absorptive inorganic reflection at the determined wavelength for photolithography. The absorptivity characterized by determining the standing wave reducing effect of the formed absorptive inorganic antireflection film by associating the refractive index value of the anti-reflection film with the amplitude data of the standing wave prepared in advance. Inorganic antireflection film Quality determination method. (3) The value of the refractive index of the absorptive inorganic antireflection film at the determined wavelength for performing photolithography corresponds to the target line width set in the amplitude data of the standing wave prepared in advance. The film quality determination method for the absorptive inorganic antireflection film according to (2) above, which determines whether or not the absorptive inorganic antireflection film formed on the underlying substrate is acceptable by determining which one of them belongs. (4) A method for determining the film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, the exposure wavelength at which photolithography is performed on the absorptive inorganic antireflection film formed on the base substrate. The reflectance at the wavelength is measured by irradiating the above-mentioned light, and the reflectance obtained above is calculated from the correlation between the reflectance prepared in advance and the reflectance of the resist-base substrate interface in the state where the resist is laminated. -Correspond with the data of the relationship between the resist-underlying substrate interface reflectance and the magnitude of the standing wave amplitude obtained by converting the obtained resist-underlying substrate interface reflectance with the previously prepared line width. A method for determining an absorptive inorganic antireflection film, characterized by determining the standing wave reducing effect of the absorptive inorganic antireflection film. (5) Correlate the obtained resist-underlying substrate interface reflectance with the data on the relationship between the resist-underlying substrate interface reflectance according to the line width prepared in advance and the magnitude of the standing wave amplitude for which the allowable range is set. The film quality determination method for the absorptive inorganic antireflection film according to (4) above, which determines whether or not the absorptive inorganic antireflection film formed on the base substrate is acceptable. (6) A method for determining the film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, which comprises irradiating an absorptive inorganic antireflection film formed on the base substrate with X-rays. The absorptive inorganic antireflective film was measured from the correspondence between the X-ray diffraction intensity of the absorptive inorganic antireflective film and the above-obtained X-ray diffraction intensity and the previously prepared data on the relationship between the X-ray diffraction intensity and the refractive index. The refractive index of the absorptive inorganic antireflective film at the exposure wavelength at which the obtained photolithography is determined and the value of the refractive index of the absorptive inorganic antireflection film are associated with the amplitude data of the standing wave prepared in advance to form the absorptivity A method for determining a film quality of an absorptive inorganic antireflection film, which comprises determining a standing wave reducing effect of the inorganic antireflection film. (7) The value of the refractive index of the absorptive inorganic antireflection film at the exposure wavelength at which the obtained photolithography is performed corresponds to the aiming line width set in the amplitude data of the standing wave prepared in advance. The film quality determination method for the absorptive inorganic antireflection film according to (6) above, which determines whether or not the absorptive inorganic antireflection film formed on the underlying substrate is acceptable by determining which region the region belongs to. (8) A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the base substrate is irradiated with electromagnetic waves. Therefore, based on the data obtained by the measuring device and the data obtained by the measuring device and the data prepared in advance, the resist is actually laminated on the absorptive inorganic antireflection film to perform photolithography. An apparatus for determining a film quality of an absorptive inorganic antireflection film, comprising: a determining unit that determines a standing wave reducing effect of the absorptive inorganic antireflection film when performing. (9) A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the base substrate is irradiated with light for absorption. Of the refractive index value at a wavelength different from the exposure wavelength for actually performing photolithography and the film thickness of the hydrophilic inorganic antireflection film, the measured refractive index data, and the spectral refractive index data prepared in advance. Corresponding means for obtaining the spectral refractive index curve, means for obtaining the value of the refractive index of the absorptive inorganic antireflection film at the exposure wavelength for performing photolithography from the spectral refractive index curve obtained by the means, and the means By associating the refractive index data of the absorptive inorganic antireflection film at the wavelength for performing the required photolithography and the amplitude data of the standing wave prepared in advance,
A film quality determination device for an absorptive inorganic antireflection film, comprising means for determining a standing wave reduction effect of the formed absorptive inorganic antireflection film. (10) A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist,
An absorptive inorganic antireflection film formed on the base substrate is subjected to photolithography, and a measuring device for irradiating light with an exposure wavelength to obtain the reflectance at that wavelength, and a preliminarily prepared reflectance and a resist are laminated. Means for converting the reflectance obtained by the above-mentioned measuring device into the resist-underlying substrate interface reflectance from the data of the correlation between the resist-underlying substrate interface reflectance in the above-mentioned state, and the resist-underlying substrate converted by the means The standing wave reduction effect of the absorptive inorganic antireflection film can be determined by correlating the interface reflectance with the data of the relationship between the previously prepared resist-base substrate interface reflectance and the magnitude of the standing wave amplitude. A device for determining an absorptive inorganic antireflection film, which comprises: (11) A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist,
A measuring device for irradiating an absorptive inorganic antireflection film formed on the underlying substrate with X-rays to obtain an X-ray diffraction intensity of the absorptive inorganic antireflection film, and an X-ray diffraction intensity obtained by the measuring device. And a means for obtaining the refractive index of the absorptive inorganic antireflection film from the comparison of the data of the relationship between the X-ray diffraction intensity and the refractive index, which has been prepared in advance, and the absorption at the exposure wavelength for performing photolithography obtained by the means. Means for determining the standing wave reducing effect of the formed absorptive inorganic antireflective film by associating the value of the refractive index of the porous inorganic antireflective film with the amplitude data of the standing wave prepared in advance. A film quality determination device for an absorptive inorganic antireflection film, which is characterized in that (12) An apparatus for forming an absorptive inorganic antireflection film on a base substrate to be patterned by a chemical vapor deposition method or a physical vapor deposition method, and the film quality determination apparatus according to any one of (8) to (11) above. An apparatus for determining film formation, comprising:

[0011]

According to the method for determining the film quality of the absorptive inorganic antireflection film of the present invention, first, the absorptive inorganic antireflection film is formed on the underlying substrate to be patterned, and the formed absorptive inorganic antireflection film is exposed to light, X Absorption formed by irradiating electromagnetic waves such as lines to measure directly or indirectly specific values such as the refractive index of the absorptive inorganic anti-reflection film itself, which directly or indirectly measure the film quality. The effect of the standing wave reduction of the porous inorganic antireflection film is determined. There are various possible combinations of such measurement methods and determination methods, and three types have been proposed in the present invention.

That is, the first method is to determine the refractive index of the absorptive inorganic antireflection film by irradiating light such as polarized light. In this case, the absorptive inorganic antireflection film formed is exposed to light. The refractive index at the wavelength for direct photolithography by irradiation is determined by 248n at the KrF excimer exposure wavelength.
At the wavelength of m, since the intensity is small and it is difficult to make an accurate determination, the refractive index at the wavelength at which the intensity is large and an accurate determination can be made is indirectly obtained. Further, by determining the standing wave reducing effect from the refractive index, the standing wave reducing effect of the antireflection film can be determined accurately and with high throughput, and preferably whether or not it can be used for photolithography is determined. Is.

The second method focuses on that the magnitude of the standing wave is determined by the reflectance of the interface between the resist and the underlying substrate,
The reflectance is measured by irradiating the absorptive inorganic antireflection film with light,
Corresponding to the data prepared in advance, it is converted into the reflectivity of the resist-base substrate interface, and the standing wave reduction effect is judged based on that reflectivity, thereby reducing the standing wave of the antireflection film with high accuracy and high throughput. The effect is determined, and preferably, it is also determined whether or not it can be used for photolithography.

In the third method, X-rays are used as an electromagnetic wave, the content of Si, for example, is determined by the X-rays, the refractive index of the absorptive inorganic antireflection film is determined from the content, and the standing index is determined from the refractive index. By determining the wave reduction effect, the standing wave reduction effect of the antireflection film can be accurately determined with high throughput.
It is preferable to determine whether or not it can be used for photolithography.

Further, the film quality judging device of the present invention corresponds to the above-mentioned method, and is based on a measuring device for irradiating electromagnetic waves to obtain specific data, and data obtained by this measuring device and data prepared in advance. And a means for determining the film quality of the absorptive inorganic antireflection film. Specifically, it has a measuring device and a judging means corresponding to the first to third methods.

Photolithography of the formed absorptive inorganic antireflective film is achieved by using these film quality evaluation devices and a film formation determination device in combination with a CVD or PVD device for forming an absorptive inorganic antireflective film. The determination of the effect of reducing the standing wave at the wavelength for performing can be accurately and promptly performed immediately after the film formation, and the film formation state can be monitored.

[0017]

EXAMPLES The present invention will be described in detail below.
The present invention is not limited to the examples below. The type of the absorptive inorganic antireflection film according to the present invention is not particularly limited, but the above-mentioned SiO _x N proposed by the present inventors is proposed.
_y : H (SiO _x N _y containing hydrogen) film or S
i _N H _w : H film (see Japanese Patent Application No. 4-359750, also Si _N H _w containing hydrogen) or an amorphous carbon film containing hydrogen (aC: H film). However, the present invention is not limited to this, and any one can be used as long as it functions as an absorptive inorganic antireflection film that is formed by CVD or PVD and is interposed between the base substrate to be patterned and the resist. It is possible. The present method and apparatus can be suitably applied to an inorganic antireflection film of a type in which the film quality easily changes under the conditions of CVD and PVD. [Embodiment 1] In this embodiment, a method of judging the ability of an antireflection film from the refractive index of an absorptive inorganic antireflection film at a wavelength for performing photolithography and showing whether or not it can be used for photolithography And the device.

As an apparatus for measuring the refractive index, a spectroscopic ellipsometer (spectral ellipsometer) or the like is usually used when absorption is intended like an inorganic absorption film. Spectral ellipso is 200
This is a device for obtaining a refractive index using polarized light in a wavelength range of about 800 nm. When obtaining the refractive index using spectral ellipsometry, usually, a wavelength range without absorption is found, the complex refractive index n and d (film thickness) are obtained using the wavelength, and the complex refraction at each wavelength is calculated from the obtained film thickness. Find the k and n of the rates.

However, when the refractive index is obtained using this method, for example, 248 nm at the KrF excimer exposure wavelength is used.
At that wavelength, the intensity is small and it is difficult to make an accurate determination. Also, it is disadvantageous in terms of throughput. For this reason,
In this embodiment, the refractive index is obtained by an apparatus having the following method or algorithm, and the absorptive inorganic antireflection film is accurately determined with high throughput.

That is, as shown in the flowchart of FIG. 1, the following procedure can be performed. <Procedure 1> As shown in FIG. 1 <1>, a wavelength range (a shaded area in the figure) in which the film is not absorbed by a spectroscopic ellipso or other ellipso is obtained in advance. In the wavelength range where there is no absorption, the film thickness is obtained by using a spectroscopic ellipso or an ellipso that can be set to the wavelength. <Procedure 2> As shown in FIG. 1 <2>, a database is prepared in advance by obtaining a spectral refractive index due to a change in film quality.
In the database, as shown by the shaded area in FIG. 1 <2>, the refractive index is obtained using the wavelength having the highest sensitivity due to the film quality and the large spectral ellipso intensity.
This is obtained by changing the wavelength, for example, 1 to 3 times. <Procedure 3> In <Procedure 2>, the refractive indexes obtained at 1 to 3 points were made to correspond to this using a database in which spectral refractive indexes prepared in advance were registered, and measured as shown in FIG. 1 <3>. A spectral refractive index curve in the absorptive inorganic antireflection film is obtained. <Procedure 4> From the obtained spectral refractive index curve, the refractive index at a wavelength for performing photolithography, for example, 248 nm in KrF excimer laser lithography is determined. Of course, not limited to this wavelength, ArF (193 nm), i-line (365n)
m) and other wavelengths are available. <Procedure 5> As shown in FIG. 1 <5>, an amplitude diagram of the standing wave in each base substrate is prepared in advance as a database, and the amplitude diagram and the target area of the amplitude by inputting the target line width, From the rejected area, it is determined where the refractive index obtained in <Procedure 4> corresponds to the amplitude diagram of this database. Although FIG. 1 <5> is expressed in two dimensions, it is actually a three-dimensional graph. In addition, in this figure, pass areas are set in advance for each line width (hatched portions in the figure). <Procedure 6> Whether the film is photolithographically pass or fail is determined by whether or not the refractive index obtained in <Procedure 4> is in the pass area. <Procedure 7> The inorganic film is peeled off by a dry or wet method such as ashing or HF. <Procedure 8> A film is formed as a monitor wafer.

It should be noted that steps 6 and 7 can be omitted. As a device that realizes the above-described flowchart, a film formation determination device as shown in FIG. 3 can be exemplified. This film formation determination device is composed of a CVD device (not shown) for forming an absorptive inorganic antireflection film on a wafer, and a film quality determination device provided adjacent to or integrally with this CVD device. The film quality determination device includes a measurement chamber in which a spectroscopic ellipso for measuring the refractive index of the formed absorptive inorganic antireflection film is arranged, and an inorganic film peeling chamber for peeling the inorganic film of the wafer transferred from the measurement chamber. And an electronic computer that receives measurement data from the spectroscopic ellipso and processes it.

Explaining the operation of this film quality judging device, first, an absorptive inorganic antireflection film is formed by CVD under a predetermined condition directly on a wafer or on a base substrate to be patterned provided on the wafer. After directly evaluating the wafer on which the absorptive inorganic antireflection film was formed, or directly without evaluation, the wafer was transferred into the measurement chamber, and the spectroscopic ellipso measurement was performed on the stage, and the spectroscopic ellipso data was stored in the database. It is processed by an electronic computer, and it is immediately determined whether or not the formed absorptive inorganic antireflection film satisfies a predetermined standing wave reducing effect. If necessary, based on this judgment, the CVD device is immediately fed back to adjust the conditions. The wafer after the measurement is then transferred to the inorganic film peeling chamber, where the inorganic film is peeled by a dry method or a wet method so that the wafer can be reused. The wafer from which the inorganic film has been peeled off is sent again to the CVD process if necessary.

In this apparatus, a Bare-Si wafer is used as a monitor, and a wafer to be actually manufactured in CVD and a monitor wafer are simultaneously formed into a film to form a C film.
A method of integrating with the VD device can be considered. Further, it goes without saying that the measurement points and locations on the wafer surface can be freely set. [Embodiment 2] This embodiment is a method and apparatus for judging the ability of the absorptive inorganic antireflection film from the reflectance of the absorptive inorganic antireflection film and showing whether or not it can be used for photolithography. .

Usually, when performing photolithography, the magnitude of the standing wave is determined by the reflectance of the interface between the resist and the substrate.
FIG. 4 shows the relationship between the magnitude of the standing wave and the reflectance at the resist-substrate interface. From this figure, it can be seen that the higher the reflectance, the larger the standing wave. Further, as shown in FIG. 5, the reflectance at the resist-substrate interface and the reflectance at the substrate are generally different.

Based on this, an antireflection film can be evaluated accurately and at high throughput when used in photolithography by a method or an apparatus having an algorithm as described below. Hereinafter, description will be made with reference to FIG. 6, which shows a flow chart of this method.

In the method described below, since the spectral reflectance measuring device is used, the reflectance at a wavelength of 200 nm or more can be obtained. However, depending on the device used, the reflectance at a shorter wavelength than this can also be obtained. it can. <Procedure 1> A database of the reflectivity of the resist-substrate interface and the magnitude of the amplitude of the standing wave as shown in FIG. 4 is prepared in advance. As shown, the allowable range of the reflectance at the resist-substrate interface is determined. This database is created for each resist. <Procedure 2> As shown in FIG. 6 <2>, a correlation between the reflectance at the resist-substrate interface and the substrate reflectance is prepared as a database. <Procedure 3> The reflectance of the absorptive inorganic antireflection film formed by CVD or sputtering at the wavelength for photolithography is measured using a spectroreflectometer or a device having a spectroreflectometer inside. <Procedure 4> Using the database prepared in Procedure 2, the reflectance obtained in Procedure 3 is converted into the reflectance at the resist-substrate interface. <Procedure 5> Using the database prepared in Procedure 1, it is determined where in the amplitude diagram the refractive index obtained in Procedure 4 corresponds. <Procedure 6> It is judged whether the reflectance at the resist-substrate interface is acceptable or unacceptable. If it is within the allowable reflectance shown in <5> of FIG. <Procedure 7> The inorganic film is peeled off by a dry or wet method such as ashing or HF. <Procedure 8> A film is formed as a monitor wafer.

The steps 6 and 7 can be omitted. FIG. 7 shows an apparatus capable of realizing the above procedure. In this apparatus, the spectroscopic ellipso in FIG. 3 shown in the first embodiment is replaced with a spectroscopic reflectometer, and the database of the electronic computer is different, and therefore the details thereof will be omitted.

Also in this apparatus, a method of using a Bare-Si wafer as a monitor, and a wafer to be actually manufactured in CVD and a monitor wafer are simultaneously formed into a film to form a C film.
A method of integrating with the VD device can be considered. Further, it goes without saying that the measurement points and locations on the wafer surface can be freely set.

This method changes not only the KrF excimer laser wavelength (248 nm), but also ArF (193 nm) and i-line (365 nm) by changing the reflectance measurement wavelength.
It is also applicable to. [Embodiment 3] This embodiment is a method and apparatus for judging the ability of the antireflection film from the X-ray diffraction intensity of the absorptive inorganic antireflection film and judging whether or not it can be used for photolithography. .

As shown in FIG. 8, the ratio of the gas species composing the film such as SiO _x N _y : H and the ratio of the constituent elements, that is, the refractive index have a fixed relationship. Also, in the X-ray diffraction method, as shown in FIG. 9, the integrated intensity of the peak and the composition amount have a certain correlation.

By utilizing these relationships, it is possible to accurately determine whether or not the antireflection film can be used for photolithography in photolithography by a device having a method or algorithm as described below. Hereinafter, a specific description will be given with reference to FIG. 10 showing a flowchart of this method. <Procedure 1> Regarding the film to be analyzed, a database of the ratio of X-ray intensity and constituent elements as shown in FIG. 9 and FIG.
A database of constituent element ratios and refractive indexes as shown in 1 is prepared. In this case, SiO _x N _y : H, etc., as shown in FIG. 8, the Si content changes depending on the gas composition, and in the case of X-rays, O, N, and H are usually unsuitable for quantitative determination. Attention is paid to Si. <Procedure 2> A peak having a large intensity (selected so as not to affect orientation significantly) is measured by X-ray to obtain an integrated intensity. <Procedure 3> FIG. 9 and FIG. 1 of the database created in Procedure 1
From 1, the refractive index of the film is obtained. <Procedure 4> The amplitude diagram of the standing wave on each substrate as shown in Fig. 2 <5> is created in advance as a database, and the amplitude diagram and the target line width are input, and the pass / fail area of the amplitude is obtained. From the area, the position in the amplitude diagram where the refractive index found in step 3 corresponds is found. <Procedure 5> It is determined whether the film is photolithographically pass or fail. <Procedure 6> The inorganic film is peeled off by a dry method or a wet method such as ashing or HF. <Procedure 7> A film is formed as a monitor wafer.

The above steps 6 and 7 can be omitted. FIG. 12 shows an apparatus that can realize the above procedure. In this apparatus, the spectroscopic ellipso in FIG. 3 shown in the first embodiment is replaced with an X-ray diffractometer, and the database of the electronic computer is different, and the details thereof will be omitted.

Also in this apparatus, a method of using a Bare-Si wafer as a monitor, or a wafer to be actually manufactured in CVD and a monitor wafer are simultaneously formed into a film to form a C film.
A method of integrating with the VD device can be considered. Further, it goes without saying that the measurement points and locations on the wafer surface can be freely set.

This method changes not only the KrF excimer laser wavelength (248 nm) but also ArF (193 nm) and i-line (365 nm) by changing the reflectance measurement wavelength.
It is also applicable to. Examples 1 to 3 described above
According to the method and apparatus for determining the absorptive inorganic antireflection film,
Whether or not the optical film quality of the absorptive inorganic antireflection film can sufficiently reduce the standing wave at the wavelength for performing photolithography can be accurately shown with a short throughput. Moreover, since it is a non-destructive inspection, the monitor wafer can be used any number of times, which is economical. Further, since the measurement area in the wafer can be freely set, it can be set in advance in a place where defects easily occur, and the inspection accuracy is good.

[0035]

According to the method and apparatus for determining the film quality of the absorptive inorganic antireflection film of the present invention, whether or not the formed absorptive inorganic antireflection film can appropriately reduce the standing wave effect. Can be determined accurately and quickly.

Further, the film formation judging apparatus of the present invention can monitor the film formation of the absorptive inorganic antireflection film by combining the CVD apparatus or the PVD apparatus with the above film quality judging apparatus.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a film quality determination method according to a first embodiment.

FIG. 2 is a flowchart illustrating a continuation of FIG.

FIG. 3 is a schematic diagram showing a film quality determination device of Example 1.

FIG. 4 is a graph showing the relationship between the magnitude of a standing wave and the reflectance at the resist-substrate interface.

FIG. 5 is a graph showing the relationship between the reflectance of the resist-substrate interface and the reflectance of the substrate.

FIG. 6 is a flowchart illustrating a film quality determination method according to a second embodiment.

FIG. 7 is a schematic diagram illustrating a film quality determination device according to a second embodiment.

FIG. 8 is a graph showing gas species and constituent element ratios which form a SiO _x H _y : H film.

FIG. 9 is a graph showing the relationship between the integrated intensity of X-rays and the amount of Si.

FIG. 10 is a flowchart illustrating a film quality determination method according to a third exemplary embodiment.

FIG. 11 is a graph showing the dependency of n and k on the SiH ₄ / N ₂ O ratio.

FIG. 12 is a schematic diagram illustrating a film quality determination device according to a third embodiment.

FIG. 13 is a schematic diagram showing multiple interference inside a resist.

FIG. 14 is a graph showing variations in line width due to changes in resist film thickness.

15A and 15B are views for explaining an antireflection technique. FIG. 15A is a schematic diagram in which an antireflection film is formed on a resist, and FIG. 15B is a schematic diagram in which an antireflection film is formed between a resist and a substrate.

FIG. 16 is a graph showing changes in the refractive index of a SiO _x H _y : H film with changes in wavelength, where (A) is the real part of the refractive index,
(B) shows an imaginary part.

FIG. 17 is a graph showing the relationship between n and k (real part and imaginary part of complex refractive index) of a SiO _x H _y : H antireflection film.

FIG. 18 is a graph showing the standing wave reduction of a SiO _x H _y : H film, (a) is a simulation for WSi,
(B) is a simulation of Al-Si, (c)
Is actual measurement data for WSi.

[Explanation of symbols]

 ARL: Antireflection film

Claims (12)

[Claims] 1. A method for determining the film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein an electromagnetic wave is applied to the absorptive inorganic antireflection film formed on the base substrate. By irradiating, a specific value for knowing the film quality state is measured, and from this specific value, the absorptive inorganic antireflective film when a resist is actually laminated on the absorptive inorganic antireflective film and photolithography is performed. A method for determining the film quality of an absorptive inorganic antireflection film, characterized by determining the effect of reducing standing waves. 2. A method of determining the film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, which comprises irradiating light to the absorptive inorganic antireflection film formed on the base substrate. Measures the film thickness of the absorptive inorganic antireflection film and the value of the refractive index at a wavelength different from the exposure wavelength at which photolithography is actually performed. Corresponds the refractive index obtained above to the spectral refractive index prepared in advance. Then, the spectral refractive index curve is obtained, and the absorptivity at the exposure wavelength at which photolithography is performed is determined from the obtained spectral refractive index curve. A characteristic is that the effect of standing wave reduction of the formed absorptive inorganic antireflection film is determined by associating the value of the refractive index of the inorganic antireflection film with the amplitude data of the standing wave prepared in advance. Absorbable inorganic anti Method of judging film quality of anti-reflection film. 3. The obtained refractive index value of the absorptive inorganic antireflection film at the wavelength for performing photolithography is a pass region or a defect area corresponding to an aim line width set in amplitude data of standing waves prepared in advance. 3. The film quality determination method for an absorptive inorganic antireflection film according to claim 2, wherein it is determined whether the absorptive inorganic antireflection film formed on the underlying substrate is acceptable by determining which of the acceptance regions belongs. 4. A method for determining a film quality of an absorptive inorganic antireflection film interposed between an underlying substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the underlying substrate is subjected to photolithography. The reflectance obtained above was calculated from the correlation between the reflectance prepared in advance and the reflectance of the resist-base substrate interface when the resist was laminated by measuring the reflectance at that wavelength by irradiating light of the exposure wavelength. Is converted to the resist-underlying substrate interface reflectance, and the obtained resist-underlying substrate interface reflectance is the data of the relationship between the resist-underlying substrate interface reflectance and the magnitude of standing wave amplitude according to the line width prepared in advance. A method for determining an absorptive inorganic antireflection film, characterized by determining the standing wave reducing effect of the absorptive inorganic antireflection film by corresponding to 5. The relationship between the obtained resist-underlying substrate interface reflectance and the resist-underlying substrate interface reflectance according to a previously prepared line width and the magnitude of the standing wave amplitude for which an allowable range is set, The film quality determination method of the absorptive inorganic antireflection film according to claim 4, wherein it is determined whether or not the absorptive inorganic antireflection film formed on the base substrate is acceptable by corresponding. 6. A method for determining a film quality of an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the base substrate is irradiated with X-rays. Then, the X-ray diffraction intensity of the absorptive inorganic antireflection film was measured, and the absorptive inorganic reflection was found from the correspondence between the X-ray diffraction intensity obtained above and the data of the relationship between the X-ray diffraction intensity and the refractive index prepared in advance. The refractive index of the anti-reflection film was obtained, and the film was formed by associating the value of the refractive index of the absorptive inorganic anti-reflection film at the exposure wavelength at which the obtained photolithography was performed with the amplitude data of the standing wave prepared in advance. A method for determining a film quality of an absorptive inorganic antireflection film, which comprises determining a standing wave reducing effect of the absorptive inorganic antireflection film. 7. The value of the refractive index of the absorptive inorganic antireflection film at the exposure wavelength at which the obtained photolithography is performed corresponds to the aiming line width set in the amplitude data of the standing wave prepared in advance, or the pass range or The film quality determination method for an absorptive inorganic antireflection film according to claim 6, wherein it is determined whether the absorptive inorganic antireflection film formed on the underlying substrate is acceptable by determining which of the rejection regions belongs. 8. A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein an electromagnetic wave is applied to the absorptive inorganic antireflection film formed on the base substrate. A measuring device that obtains data for knowing the film quality state by irradiation, and a resist is actually laminated on the absorptive inorganic antireflection film based on the data obtained by the measuring device and the data prepared in advance. A film quality determination device for an absorptive inorganic antireflection film, comprising: a determining unit that determines a standing wave reducing effect of the absorptive inorganic antireflection film when performing lithography. 9. A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the base substrate is irradiated with light. , A film thickness of the absorptive inorganic antireflection film and a measuring device for obtaining the value of the refractive index at a wavelength different from the exposure wavelength for actually performing photolithography, the measured refractive index data, and the spectral refractive index data prepared in advance And a means for obtaining a spectral refractive index curve corresponding to the above, and a means for obtaining a value of the refractive index of the absorptive inorganic antireflection film at the exposure wavelength for performing photolithography from the spectral refractive index curve obtained by the means, The film was formed by associating the refractive index data of the absorptive inorganic antireflection film at the wavelength for performing photolithography determined by the method with the amplitude data of the standing wave prepared in advance. A film quality determination device for an absorptive inorganic antireflection film, comprising: means for determining a standing wave reduction effect of the absorptive inorganic antireflection film. 10. A film quality determination device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein photolithography is performed on the absorptive inorganic antireflection film formed on the base substrate. A measuring device that irradiates light of the exposure wavelength to obtain the reflectance at that wavelength, and the above-mentioned measuring device from the data of the correlation between the reflectance and the resist-base substrate interface reflectance in the state where the reflectance and the resist are laminated in advance. Means for converting the reflectance obtained in step 1 into the reflectance of the resist-underlying substrate interface, and the reflectance of the resist-underlying substrate interface converted by the means, with the previously prepared resist-underlying substrate interface reflectance and standing wave. And a means for determining the standing wave reducing effect of the absorptive inorganic antireflection film by associating with the data of the relationship with the magnitude of the amplitude of Machine antireflection film determination device. 11. A film quality judging device for an absorptive inorganic antireflection film interposed between a base substrate to be patterned and a resist, wherein the absorptive inorganic antireflection film formed on the base substrate is irradiated with X-rays. And a measuring device for obtaining the X-ray diffraction intensity of the absorptive inorganic antireflection film, and a comparison between the X-ray diffraction intensity obtained by the measuring device and the data of the relation between the X-ray diffraction intensity and the refractive index, which are prepared in advance. Means for obtaining the refractive index of the absorptive inorganic antireflection film from the above, the value of the refractive index of the absorptive inorganic antireflection film at the exposure wavelength for performing photolithography obtained by the means, and the amplitude of the standing wave prepared in advance A film quality determination device for an absorptive inorganic antireflection film, comprising means for determining a standing wave reducing effect of the formed absorptive inorganic antireflection film by associating with the data. 12. An apparatus for forming an absorptive inorganic antireflection film on a base substrate to be patterned by a chemical vapor deposition method or a physical vapor deposition method, and the film quality judging apparatus according to claim 8. A film forming determination apparatus comprising: