JP2001035832A - Dry etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry etching method which can achieve a good etching profile and less degradation in the quality of an organic, low permittivity insulating film. SOLUTION: A dry etching method for a laminated film containing an organic, low permittivity insulated film 103 formed as an interlayer dielectric uses, as an etching gas, a mixed gas prepared by mixing a first gas containing one of hydrogen and nitrogen or both with a second gas easily separating phosphorous, sulfur or silicon, or a mixed gas prepared by mixing the first and second gases with a third gas of a noble gas, or a mixed gas prepared by mixing the second gas with the third gas. Such an etching gas is introduced into a vacuum container wherein a semiconductor substrate is placed. Then, a plasma is generated by applying high frequency power to plasma generating means, and the film 103 formed on the surface of the semiconductor substrate is etched using the plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dry etching an organic low dielectric constant insulating film used for an interlayer insulating film of a semiconductor device, and more particularly, to a method for processing an organic low dielectric constant insulating film at high speed and with high processing accuracy. The present invention relates to a dry etching method which performs processing without deterioration of film quality and poor embedding of metal wiring.

[0002]

2. Description of the Related Art A conventional etching process for an organic low dielectric constant insulating film will be described with reference to FIG. In FIG. 2, 2
01 is a resist mask, 202 is a silicon oxide film, 20
Reference numeral 3 denotes an organic low dielectric constant insulating film, 204 denotes a metal wiring, 205 denotes a wiring groove or via hole, and 206 denotes a side wall protective film.

Since the organic low dielectric constant insulating film alone has problems in hygroscopicity, mechanical strength, plasma resistance and the like, generally, as shown in FIG. 2, a silicon oxide film or the like by plasma CVD is formed thereon. Cover and use. When a wiring groove or via hole having a damascene structure is formed in this film, the following procedure is performed.

First, as shown in FIG. 2 (a), after forming a resist mask for forming a groove or a hole, an upper silicon oxide film is etched (FIG. 2 (b)). Etching of the low dielectric constant insulating film (FIG. 2)
(C)). The etching of the upper silicon oxide film is performed using a fluorocarbon-based gas (for example, a C ₄ F ₈ / CO / Ar / O ₂ -based gas) which has been generally used conventionally.

The organic low dielectric constant insulating film can be generally etched by oxygen plasma. For example, as disclosed in Japanese Patent Application Laid-Open No. 8-316209,
_{2. The use} of plasma of CO ₂ gas makes it possible to easily etch most organic low dielectric constant insulating films at a high etching rate. However, Proceedings of the 59th Annual Meeting of the Japan Society of Applied Physics (Autumn 1998), 15p-C-
As described in FIG. 10, the organic substance reacts not only with oxygen ions but also with oxygen radicals, and the etching proceeds isotropically. Therefore, the cross-sectional shapes of the holes and grooves are as shown in FIG. It tends to be a barrel-shaped shape called a so-called Boeing shape. With such a shape, in the subsequent wiring metal film forming process, a defective filling of the metal into the hole or the groove occurs, which causes a defect such as an increase in wiring resistance or, in the worst case, a disconnection of the wiring.

As described above, when the protective film is not formed on the side wall of the organic low dielectric constant insulating film, no matter how the gas system or the etching conditions are adjusted, the vertical shape can be ensured.
Oxygen radicals are generated due to oxygen existing in the organic low dielectric constant insulating film, and the oxygen radicals cause the organic low dielectric constant insulating film to be etched, resulting in a bowing shape as shown in FIG. When an ashing step of a resist mask is performed after an organic low dielectric constant insulating film etching step, oxygen radicals generated in plasma cause
Etching of the organic low dielectric constant insulating film further proceeds. From the above results, it can be said that in the step of etching the organic low dielectric constant insulating film, the formation of the plasma-resistant side wall protective film is indispensable.

[0007] Further, another disadvantage of etching by oxygen plasma is, for example, Proceedin.
gs of Symposium on Dry Pr
ossess 1998 p. 175, there is a problem of deterioration of film quality. That is, this means that the organic low dielectric constant insulating film exposed to the oxygen plasma forms an altered layer that adsorbs oxygen or combines with oxygen,
There is a problem in that this oxygen is desorbed during a subsequent wiring metal forming step, for example, a CVD step of a tungsten plug, thereby causing defective filling of holes and grooves.

In order to solve the above problems, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 10-189543, a side wall processed with sulfur is processed while processing with oxygen plasma using SO ₂ gas. Methods have been proposed to protect and prevent deterioration of film quality. However, even if this gas system is used, deterioration of the film cannot be prevented, and defective filling still occurs in the tungsten plug process.

As described above, in the etching of an organic low-dielectric-constant insulating film using an oxygen-based gas, despite the high etching rate, deterioration of the film quality cannot be avoided. It is necessary to perform etching using a gas system that contains only gas.

As an example of etching an organic low dielectric constant film with a gas other than an oxygen-based gas, see, for example, Japanese Patent Application Laid-Open No. 10-1501.
No. 05 discloses a fluorocarbon-based gas (for example, C ₄ F ₈ / CO / Ar /) used for etching SiO ₂ which has been widely and conventionally used as an interlayer insulating film.
An example in which O ₂ -based gas) is directly applied is disclosed. However, only a fluorine-containing organic low dielectric constant insulating film (for example, a fluorinated polyaryl ether represented by the following general formula (1)) can be etched at a high speed with a fluorocarbon-based gas and does not contain fluorine. Since the etching rate of an organic low dielectric constant insulating film (for example, a polyaryl ether represented by the following general formula (2)) is about 1/10 of that containing fluorine, it should be applied to actual semiconductor production. Could not.

[0011]

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[0012]

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[0013]

As described above, in the case of plasma using an oxygen-based gas, there is a problem that deterioration of film quality due to adsorption of oxygen to an organic low dielectric constant insulating film cannot be avoided.

Further, with a fluorocarbon-based gas, a fluorine-containing organic low dielectric constant insulating film can be etched at a high speed, but with an organic low dielectric constant insulating film containing no fluorine, an etching sufficient for mass production can be performed. There was a problem that speed could not be obtained.

Further, in the step of etching the organic low dielectric constant insulating film, unless the side surface of the organic low dielectric constant insulating film is covered with the protective film, the organic low dielectric constant insulating film itself is etched. There is a problem that the shape is broken by oxygen radicals or oxygen radicals generated in the ashing process.

Therefore, in order to solve the conventional problems, in order to prevent the deterioration of the film quality of the organic low dielectric constant insulating film, a gas system containing no oxygen is adopted, and a strong side wall protective film is formed. It was necessary to find a gas system and an etching apparatus capable of obtaining an etching rate sufficient for mass production.

An object of the present invention is to provide a dry etching method which has a good etching shape and does not deteriorate the quality of an organic low dielectric constant insulating film.

[0018]

According to the present invention, in a dry etching method for a laminated film including an organic low dielectric constant insulating film formed as an interlayer insulating film, a gas containing one or both of hydrogen and nitrogen as an etching gas is provided. A mixed gas of (a first gas) and a gas that easily releases phosphorus or sulfur or silicon (a second gas), or a gas containing one or both of hydrogen and nitrogen (a first gas) and phosphorus or sulfur Alternatively, a mixed gas of a gas that easily releases silicon (second gas) and a rare gas (third gas), or a gas that easily releases phosphorus, sulfur, or silicon (second gas) and a rare gas ( Mixed gas with a third gas) into a vacuum vessel in which the semiconductor substrate is installed, and apply high frequency power to the plasma generating means to generate plasma, and form the plasma on the surface of the semiconductor substrate using the plasma. The dry etching method for etching the organic low dielectric constant insulating film is provided.

[0019]

Embodiments of the present invention will be described below in detail.

The dry etching method of the present invention will be described with reference to FIG. In FIG. 1, 101 is a resist mask, 102 is a silicon oxide film, 103 is an organic low dielectric constant insulating film, 104 is a metal wiring, 105 is a wiring groove or via hole, and 106 is a side wall protective film.

For the organic low dielectric constant insulating film, for example, a material having the structural formula shown in the general formula (1) or (2) is used. The film structure is exactly the same as that of the conventional example shown in FIG. 2. Since the organic low-dielectric-constant insulating film alone has problems in hygroscopicity, mechanical strength, plasma resistance, etc., silicon oxide by plasma CVD is formed thereon. Use it covered with a membrane. The process of forming a wiring groove or via hole having a damascene structure in this film is the same as that of the conventional example shown in FIG.

First, as shown in FIG. 1 (a), after forming a resist mask for forming a groove or a hole, the upper silicon oxide film is etched (FIG. 1 (b)). The low dielectric constant insulating film is etched (FIG. 1)
(C)). The etching of the upper silicon oxide film is performed using a fluorocarbon-based gas (for example, a C ₄ F ₈ / CO / Ar / O ₂ -based gas) which has been generally used conventionally.

The gas used in the dry etching method for an organic low dielectric constant insulating film according to the present invention is a gas containing hydrogen and / or a gas containing nitrogen (first gas) and a gas containing phosphorus, sulfur or silicon. A mixed gas with a gas that easily releases (second gas), or a gas containing hydrogen and / or a gas containing nitrogen (first gas) and a gas that easily releases phosphorus or sulfur or silicon (second gas) Gas) and a rare gas (third gas), or a mixed gas of a gas (second gas) and a rare gas (third gas) that easily releases phosphorus, sulfur, or silicon.

When the above gas is introduced into a vacuum vessel and high frequency power is applied to generate plasma, the plasma contains
Hydrogen ions, radicals and / or nitrogen ions, radicals, and phosphorus, sulfur, and silicon atoms are generated. When hydrogen ions and / or nitrogen ions are incident on the semiconductor substrate where the organic low dielectric constant insulating film is exposed, carbon, nitrogen, hydrogen, and oxygen, which are constituent elements of the organic low dielectric constant insulating film, are formed. , Fluorine are CH _x , NH _x , C
It is volatilized in the form of N, H ₂ , H ₂ O, HF, and the etching reaction proceeds. On the other hand, on the side of the pattern where no ions are incident, phosphorus, sulfur or silicon atoms adhere and polymerize to form a polymer film mainly containing the above elements.

Since the reaction between hydrogen ions and nitrogen ions and the organic low dielectric constant insulating film is an ion assisted reaction, it is considered that the anisotropic shape is maintained even if a polymer film is not formed on the side surface of the pattern. Tends to. However, the general formula (1)
Alternatively, as is clear from the general formula (2), since oxygen is contained in the organic low dielectric constant insulating film, oxygen generated by etching becomes oxygen radicals in plasma,
Since the pattern side wall is etched by the oxygen radical, the side wall protective film is indispensable even in a gas system containing no oxygen.

Although FIG. 1 shows an example in which only the upper layer of the organic low dielectric constant insulating film is covered with the silicon oxide film, a structure in which the upper and lower portions of the organic low dielectric constant insulating film are sandwiched between silicon oxide films can also be considered. . In this case, it is necessary to etch the lower silicon oxide film after the etching of the organic low dielectric constant insulating film. At this time, if the side wall protection is performed during the etching of the organic low dielectric constant insulating film, the organic silicon oxide is generated by the oxygen or fluorine radicals generated in the plasma in the subsequent step of etching the lower silicon oxide with the fluorocarbon-based gas. The dielectric insulating film is not etched, and a good etched shape can be obtained.

A minimum amount of hydrogen ions required for the reaction,
As a gas for generating phosphorus, sulfur or silicon atoms, a single gas or a mixed gas of hydride gases such as PH ₃ , H ₂ S and SiH ₄ is sufficient. However, the P / H ratio of the source gas (the ratio of the number of phosphorus atoms to the number of hydrogen atoms) or S
/ H ratio (ratio of the number of sulfur atoms to the number of hydrogen atoms) or Si /
By controlling the H ratio (the ratio between the number of silicon atoms and the number of hydrogen atoms), the etching rate and the thickness of the sidewall protective film can be controlled. Thus, by adding hydrogen gas, the P / H ratio, S / H ratio, or Si / H ratio can be controlled in a wider range, and the process window can be widened.

Further, by adding nitrogen gas to the above-mentioned gas, the sputtering effect is increased and the etching rate is improved, and nitrogen is also added to the side wall protective film to form a stronger film. Similar effects can be obtained by introducing a gas such as NH ₃ (ammonia) or N ₂ H ₄ (hydrazine) instead of introducing a mixed gas of nitrogen and hydrogen.

Furthermore, for example, He, Ne, A
By adding a rare gas such as r, Kr, Xe and Rn, an improvement in plasma density is expected, and a sputtering efficiency by ions is also improved, so that a higher etching rate can be obtained.

The plasma processing apparatus used in the dry etching method of the present invention uses a plasma as dense as possible from the viewpoint of securing a sufficiently high etching rate even with a gas having a low reactivity such as hydrogen or nitrogen. It is desirable that the plasma processing apparatus be capable of generating plasma. Examples of the plasma processing apparatus preferably used in the present invention include, for example, an ECR type plasma processing apparatus, a helicon wave type plasma processing apparatus, an ICP type plasma processing apparatus, and a SWP type.
Type plasma processing apparatus, SIP type plasma processing apparatus, and the like, but the present invention is not limited to the plasma apparatus, and a plasma apparatus capable of generating high density plasma of 1 × 10 ¹¹ cm ⁻³ or more. If it is, any device can be applied.

[0031]

EXAMPLES The dry etching method of the present invention will now be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 As a first example of the present invention, results of etching an organic low dielectric constant film using H ₂ gas and H ₂ S gas will be described. In this embodiment, E
Etching was performed using a CR type plasma etching apparatus. In addition, a series of etching processes of the stacked interlayer insulating films were all performed in the same processing chamber.

First, a silicon substrate having the sectional structure shown in FIG. 1A was prepared. Here, the upper silicon oxide film 102 is made of plasma TEOS SiO _{2 having a} thickness of 200 nm.
The organic low dielectric constant insulating film 103 is spin-coated to a thickness of 8
00 nm polyarylether, metal wiring 104 is a 500 nm thick Al-Cu film, and base is plasma TE
This is a structure of an OS SiO ₂ 1 μm / Si substrate (not shown). This wafer is placed on a substrate support of an ECR type plasma etching apparatus, and a turbo molecular pump is used to
The inside of the vacuum vessel was evacuated until the pressure reached 1 × 10 ⁻⁶ Torr.

Next, a plasma is generated under the following conditions.
The upper silicon oxide film was etched.

Gas type, flow rate: C ₄ F ₈ / CO / Ar / O ₂
= 15/150/200/5 sccm Pressure: 40 mTorr Substrate temperature: 20 ° C. Magnetic field: 875 Gauss Microwave power: 1 kW Substrate RF frequency, power: 13.56 MHz, 400 W

At this time, Vdc of the substrate support is about -200.
V. The above etching treatment was performed for 20 seconds, and all the upper silicon oxide film 102 was removed. The end point of the etching of the silicon oxide film was determined by a change in the emission intensity of SiF (wavelength: 640 nm) using a plasma emission intensity monitor.

Next, after evacuating the vacuum chamber for 30 seconds,
Plasma was generated under the following conditions, and the organic low dielectric constant insulating film was etched.

Gas type, flow rate: H ₂ / H ₂ S = 100/15 sccm Pressure: 10 mTorr Substrate temperature: 20 ° C. Magnetic field: 875 Gauss Microwave power: 1 kW RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -110.
V. The above etching treatment was performed for 6 minutes, and the entire organic low dielectric constant insulating film 103 was removed. The end point of the etching of the organic low-dielectric-constant insulating film was determined by a change in the emission intensity of CH (wavelength: 431 nm) using a plasma emission intensity monitor. The etching rate of the film calculated from the etching time was about 130 nm / min, which was slightly lower for application to production.

After all the above processes were completed, the resist mask was removed as necessary, and after the steps of cleaning and barrier metal film formation, tungsten plug film formation was performed. When the cross section of the wafer after film formation was observed by SEM, it was confirmed that the via hole had no shape abnormality such as bowing and that tungsten was normally embedded.

Example 2 As a second example of the present invention, results of etching an organic low dielectric constant film using H ₂ gas and H ₂ S gas will be described. In this embodiment, E
Etching was performed using a SIP type plasma etching apparatus instead of the CR type plasma etching apparatus. Also,
A series of etching processes for the stacked interlayer insulating films were all performed in the same processing chamber.

First, a silicon substrate having the same cross-sectional structure as in Example 1 was prepared. The wafer was placed on a substrate support of an SIP type plasma etching apparatus, and the inside of the vacuum vessel was evacuated using a turbo molecular pump until the pressure reached 1 × 10 ⁻⁶ Torr.

Next, a plasma is generated under the following conditions.
The upper silicon oxide film was etched.

Gas type, flow rate: C ₄ F ₈ / Ar / O ₂ = 15
/ 150/5 sccm Pressure: 30 mTorr Substrate temperature: 0 ° C. Microwave power: 1.5 kW Substrate RF frequency, power: 13.56 MHz, 350 W

At this time, Vdc of the substrate support is about -150.
V. The above etching process was performed for 12 seconds, and the entire upper silicon oxide film 102 was removed. The end point of the etching of the silicon oxide film was determined by a change in the emission intensity of SiF (wavelength: 640 nm) using a plasma emission intensity monitor.

Next, after evacuating the vacuum chamber for 30 seconds,
Plasma was generated under the following conditions, and the organic low dielectric constant insulating film was etched.

Gas type, flow rate: H ₂ / H ₂ S = 100/15 sccm Pressure: 5 mTorr Substrate temperature: 0 ° C. Microwave power: 1.5 kW Substrate RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -100.
V. Perform the above etching process for 120 seconds,
All of the organic low dielectric constant insulating film 103 was removed. The end point of the etching of the organic low-dielectric-constant insulating film was determined by a change in the emission intensity of CH (wavelength: 431 nm) using a plasma emission intensity monitor. The etching rate of the film calculated from the etching time was about 400 nm / min, which was a value applicable to production.

After all the above processes were completed, the resist mask was removed if necessary, and after the steps of cleaning and barrier metal film formation, tungsten plug film formation was performed. When the cross section of the wafer after film formation was observed by SEM, it was confirmed that the via hole had no shape abnormality such as bowing and that tungsten was normally embedded.

(Embodiment 3) As a third embodiment of the present invention, results of etching an organic low dielectric constant film using H ₂ gas and PH ₃ gas will be described. In the present embodiment, similarly to the second embodiment, the etching was performed using the SIP type plasma etching apparatus.

First, a silicon substrate having the same cross-sectional structure as in Example 1 was prepared, and the upper silicon oxide film was etched in the same procedure as in Example 2.

Next, the organic low dielectric constant insulating film was etched under the following conditions.

Gas type, flow rate: H ₂ / PH ₃ = 100/15 sccm Pressure: 5 mTorr Substrate temperature: 0 ° C. Microwave power: 1.5 kW Substrate RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -100.
V. Perform the above etching process for 110 seconds,
All of the organic low dielectric constant insulating film 103 was removed. The etching rate of the film calculated from the etching time is about 430 nm
/ Min.

After all the etching processes were completed, the resist mask was removed as necessary, and after the steps of cleaning and barrier metal film formation, a tungsten plug was formed. The cross section of the wafer after film formation was observed with a SEM, and there was no shape abnormality such as bowing in the via hole shape.
It was also confirmed that tungsten was buried normally.

Example 4 As a fourth example of the present invention, the results of etching an organic low dielectric constant film using H ₂ gas, N ₂ gas and SiH ₄ gas will be described. Also in this embodiment, similarly to the second embodiment, the etching was performed using the SIP type plasma etching apparatus.

First, a silicon substrate having the same cross-sectional structure as in Example 1 was prepared, and the upper silicon oxide film was etched in the same procedure as in Example 2.

Next, the organic low dielectric constant insulating film was etched under the following conditions.

Gas type, flow rate: H ₂ / N ₂ / SiH ₄ = 10
0/50/15 sccm Pressure: 5 mTorr Substrate temperature: 0 ° C. Microwave power: 1.5 kW Substrate RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -100.
V. The above etching process was performed for 95 seconds, and the entire organic low dielectric constant insulating film 103 was removed. The etching rate of the film calculated from the etching time is about 505 nm /
min.

After all the etching processes were completed, the resist mask was removed as necessary, and after the steps of cleaning and barrier metal film formation, a tungsten plug was formed. The cross section of the wafer after film formation was observed with a SEM, and there was no shape abnormality such as bowing in the via hole shape.
It was also confirmed that tungsten was buried normally.

Fifth Embodiment As a fifth embodiment of the present invention, results of etching an organic low dielectric constant film using H ₂ gas, N ₂ gas, SiH ₄ gas and Ar gas will be described.
Also in this embodiment, similarly to the second embodiment, the etching was performed using the SIP type plasma etching apparatus.

First, a silicon substrate having the same cross-sectional structure as in Example 1 was prepared, and the upper silicon oxide film was etched in the same procedure as in Example 2.

Next, the organic low dielectric constant insulating film was etched under the following conditions.

Gas type, flow rate: H ₂ / N ₂ / SiH ₄ / Ar
= 100/50/15/100 sccm Pressure: 5 mTorr Substrate temperature: 0 ° C. Microwave power: 1.5 kW Substrate RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -100.
V. The above etching process was performed for 95 seconds, and the entire organic low dielectric constant insulating film 103 was removed. The etching rate of the film calculated from the etching time is about 505 nm /
min. In addition, the resist mask was completely removed after the completion of the etching of the organic low dielectric constant insulating film.

After the completion of the etching process, cleaning,
After the barrier metal film formation process, a tungsten plug was formed. When the cross section of the wafer after film formation was observed by SEM, it was confirmed that the via hole had no shape abnormality such as bowing and that tungsten was normally embedded.

(Embodiment 6) As a sixth embodiment of the present invention, a result of etching an organic low dielectric constant film using H ₂ S gas and Ar gas will be described. Also in this embodiment,
As in Example 2, etching was performed using a SIP type plasma etching apparatus.

First, a silicon substrate having the same cross-sectional structure as in Example 1 was prepared, and the upper silicon oxide film was etched in the same procedure as in Example 2.

Next, the organic low dielectric constant insulating film was etched under the following conditions.

Gas type, flow rate: H ₂ S / Ar = 100/100 sccm Pressure: 5 mTorr Substrate temperature: 0 ° C. Microwave power: 2.5 kW Substrate RF frequency, power: 13.56 MHz, 250 W

At this time, Vdc of the substrate support is about -95 V
Met. The above etching treatment was performed for 5 minutes, and the entire organic low dielectric constant insulating film 103 was removed. The etching rate of the film calculated from the etching time is about 150 nm / mi.
n.

After the etching process has been completed, cleaning,
After the barrier metal film formation process, a tungsten plug was formed. When the cross section of the wafer after film formation was observed by SEM, it was confirmed that the via hole had no shape abnormality such as bowing and that tungsten was normally embedded.

[0074]

As described above, according to the present invention, when etching an organic low dielectric constant insulating film, a gas containing one or both of hydrogen atoms and nitrogen atoms as an etching gas (first gas). Mixed gas of hydrogen and gas that easily releases phosphorus or sulfur or silicon (second gas), or gas containing one or both of hydrogen atoms and nitrogen atoms (first gas) and phosphorus or sulfur or silicon easily Mixed gas of gas (second gas) and rare gas (third gas) released to
Alternatively, by using a mixed gas of a gas (second gas) that easily releases phosphorus, sulfur, or silicon (second gas) and a rare gas (third gas), the etching shape is good and the organic low dielectric constant insulating film is It has become possible to provide a dry etching method without deterioration of the film quality.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an etching method for an organic low dielectric constant insulating film according to the present invention.

FIG. 2 is a schematic view showing a conventional method for etching an organic low dielectric constant insulating film.

[Explanation of symbols]

 101, 201 resist mask 102, 202 upper silicon oxide film 103, 203 organic low dielectric constant insulating film 104, 204 lower silicon oxide film 105, 205 wiring groove or via hole 106, 206 sidewall protective film

Claims (19)

[Claims] 1. A dry etching method for a laminated film including an organic low dielectric constant insulating film formed as an interlayer insulating film, wherein a first gas which is a gas containing one or both of hydrogen atoms and nitrogen atoms is provided. A mixed gas with a second gas, which is a gas that readily releases phosphorus or sulfur or silicon atoms, is introduced into a vacuum vessel in which the semiconductor substrate is installed, and high-frequency power is applied to the plasma generation means. A dry etching method, comprising generating plasma and etching an organic low dielectric constant insulating film formed on a surface of a semiconductor substrate using the plasma. 2. The method according to claim 1, wherein the first gas is a gas containing one or both of a hydrogen atom and a nitrogen atom, and the second gas is a gas that easily releases phosphorus or sulfur or silicon atoms. The dry etching method according to claim 1, wherein the dry etching method has a molecular structure that does not include oxygen atoms and halogen atoms. 3. A gas containing one or both of a hydrogen atom and a nitrogen atom, wherein the first gas is H ₂ , N ₂ , N ₂
The dry etching method according to claim 1, wherein the mixed gas is one or more of H ₃ and N ₂ H ₄ . 4. The method of claim 2, wherein the second gas, which is a gas that easily releases phosphorus, sulfur, or silicon atoms, is PH ₃
Or H ₂ S or dry etching method according to claim 1 which is SiH _4. 5. The dry plasma generator according to claim 1, wherein said plasma generating means is an ECR plasma source, a helicon wave plasma source, an ICP plasma source, a SWP plasma source, or a SIP plasma source. Etching method. 6. The dry etching method according to claim 1, wherein the organic low dielectric constant insulating film is a polyaryl ether or a fluorinated polyaryl ether. 7. A dry etching method for a laminated film including an organic low dielectric constant insulating film formed as an interlayer insulating film, wherein a first gas which is a gas containing one or both of a hydrogen atom and a nitrogen atom is provided. A second gas, which is a gas that readily liberates phosphorus or sulfur or silicon atoms;
A mixed gas with a third gas, which is a rare gas, is introduced into a vacuum vessel in which a semiconductor substrate is installed, and high-frequency power is applied to plasma generating means to generate plasma, and the semiconductor is formed using the plasma. A dry etching method characterized by etching an organic low dielectric constant insulating film formed on a substrate surface. 8. The dry etching method according to claim 7, wherein the third gas, which is a rare gas, is one or a mixed gas of He, Ne, Ar, Kr, Xe and Rn. . 9. The method according to claim 1, wherein the first gas is a gas containing one or both of a hydrogen atom and a nitrogen atom, and the second gas is a gas that easily releases phosphorus or sulfur or silicon atoms. The dry etching method according to claim 7, wherein the molecular structure does not include an oxygen atom and a halogen atom. 10. The first gas, which is a gas containing one or both of a hydrogen atom and a nitrogen atom, is H ₂ , N ₂ ,
The dry etching method according to claim 7, wherein the dry etching method is a mixed gas of one or more of NH ₃ and N ₂ H ₄ . 11. The second gas, which is a gas that liberates phosphorus or sulfur or silicon atoms easily, has a pH of PH.
The dry etching method according to claim 7, wherein the dry etching method is ₃ or H ₂ S or SiH ₄ . 12. The dry plasma generator according to claim 7, wherein said plasma generating means is an ECR plasma source, a helicon wave plasma source, an ICP plasma source, a SWP plasma source, or a SIP plasma source. Etching method. 13. The dry etching method according to claim 7, wherein the organic low dielectric constant insulating film is a polyaryl ether or a fluorinated polyaryl ether. 14. A dry etching method for a laminated film including an organic low-dielectric-constant insulating film formed as an interlayer insulating film, wherein a second gas that is a gas that easily releases phosphorus, sulfur, or silicon atoms is used. A mixed gas with a third gas, which is a rare gas, is introduced into a vacuum vessel in which a semiconductor substrate is installed, and high-frequency power is applied to plasma generation means to generate plasma, and the plasma is used. A dry etching method comprising etching an organic low dielectric constant insulating film formed on a surface of a semiconductor substrate. 15. The dry etching method according to claim 14, wherein the third gas, which is the rare gas, is one or a mixed gas of He, Ne, Ar, Kr, Xe, and Rn. . 16. The second gas, which is a gas that easily releases phosphorus, sulfur, or silicon atoms, has a molecular structure containing hydrogen atoms or nitrogen atoms, not containing oxygen atoms and halogen atoms. 16. The dry etching method according to 14 or 15. 17. The second gas, which is a gas that readily releases phosphorus or sulfur or silicon atoms, has a pH of PH.
The dry etching method according to claim 14, wherein the dry etching method is ₃ or H ₂ S or SiH ₄ . 18. The dry plasma generator according to claim 14, wherein said plasma generating means is an ECR plasma source, a helicon wave plasma source, an ICP plasma source, a SWP plasma source, or a SIP plasma source. Etching method. 19. The dry etching method according to claim 14, wherein the organic low dielectric constant insulating film is a polyaryl ether or a fluorinated polyaryl ether.