JP2004119539A - Method for removing resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist pattern removing method capable of preventing the side wall of an insulating film on which a pattern is etched from being exposed to an excess oxygen plasma in the case of removing a resist pattern used for the pattern etching of the insulating film as a mask by ashing processing. <P>SOLUTION: In the resist pattern removing method for removing a resist pattern 15a used for the pattern etching of an inter-layer insulating film 13 as a mask from the inter-layer insulating film 13 by the ashing processing while supplying the oxygen plasma, the ashing processing of the resist pattern 15a is performed in the supplied state of the oxygen plasma and the supplied state of carbon. Since the excess O plasma reacts with supplied C and oxide containing carbon is generated and vaporized in the ashing processing of the resist pattern, the side wall of the pattern-etched insulating film can be prevented from being exploded by the O plasma. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for removing a resist pattern, and more particularly to a method for removing a resist pattern on an insulating film formed of a material having low oxygen plasma resistance by ashing.
[Prior art]
[0002]
In recent years, with high integration of a semiconductor integrated circuit device (LSI), a wiring process technology has been increasingly regarded as important for high-speed operation of SI. This is because it has become remarkable that the wiring delay time is larger than the gate delay time due to the miniaturization of semiconductor elements.
[0003]
In order to suppress the wiring delay time, it is necessary to reduce the capacitance between wirings and lower the wiring resistance. In addition, since the current density increases with the miniaturization of semiconductor elements, it is necessary to improve electromigration (EM) resistance. In order to improve these problems, it is considered important to introduce a multilayer wiring technique using an insulating film having a low dielectric constant (low dielectric constant film) as an interlayer insulating film together with copper (Cu) wiring. .
[0004]
Since the electric resistance of the Cu wiring is about two-thirds of that of the conventional aluminum alloy wiring, a reduction in the wiring resistance can be realized, and a higher EM resistance than the Al alloy wiring is expected. The introduction to has been started.
[0005]
As a method of forming the Cu wiring, a groove wiring method such as a damascene method is generally used.
Here, a general method for forming a Cu wiring using the damascene method will be described.
First, as shown in FIG. 4, an interlayer insulating film 13 is formed on a substrate 11 via an etching stopper layer 12, and a protective film 14 is formed on the interlayer insulating film 13.
Next, a resist pattern 15a is formed on the protective film 14 by a normal lithography technique, and the protective film 14 and the interlayer insulating film 13 are pattern-etched by etching using the resist pattern 15a as a mask, thereby forming wiring grooves and connection holes. Is formed.
[0006]
Next, although not shown here, the substrate 11 is carried into the processing chamber, and oxygen (O 2) is used as a process gas. ₂ 2) O plasma is generated in the processing chamber by performing plasma discharge using gas, and the resist pattern 15a is removed by ashing.
Thereafter, the etching stopper layer 12 exposed at the bottom of the groove 16 is removed by etching, and a barrier metal film for preventing diffusion of Cu is formed on the protective film 14 so as to cover the inner wall of the groove 16. Is formed on the protective film 14 so as to embed the Cu. Then, the Cu film and the barrier metal film on the protective film 14 are removed by a chemical mechanical polishing (CMP) method or the like until the surface of the protective film 14 is exposed.
Thus, a Cu wiring is completed in the groove 16.
[0007]
In the Cu wiring as described above, silicon oxide (SiO 2) is used as the interlayer insulating film 13 in order to reduce the capacitance between wiring layers. ₂ ) SiOCH films, SiOF films, organic insulating films, and the like having a lower dielectric constant than the films are being developed and put into practical use as next-generation materials.
Although a low dielectric constant film as described above can be obtained by lowering the polarizability of a material, there is a certain limit to the lowering of the polarizability alone.
Therefore, it is considered necessary to lower the dielectric constant by making the film structure porous. Recently, a low-dielectric-constant film in which a film made of a material having a low dielectric constant is made porous has been developed and attracted attention.
[0008]
[Problems to be solved by the invention]
However, the interlayer insulating film 13 made of a low dielectric constant film as described above has a characteristic that resistance to O plasma is weak.
For this reason, in the ashing process of the resist pattern 15a used as a mask when forming the groove 16 by pattern-etching the protective film 14 and the interlayer insulating film 13, the interlayer insulating film 13 forming the side wall of the groove 16 is exposed to O plasma. Due to the exposure, the O plasma erodes the interlayer insulating film 13 and many pores are generated on the side wall of the groove 16.
When the pores absorb moisture in the atmosphere, when the barrier metal film is formed on the inner wall of the groove 16 by the groove wiring method, the barrier metal film is not only degassed but also hinders the film formation, but also adheres to the barrier metal film. In addition, there is a problem in that the dielectric constant of the interlayer insulating film 13 is increased, as well as causing a decrease in the film thickness and peeling of the film.
[0009]
In addition, by being exposed to O plasma, the interlayer insulating film 13 that forms the side wall of the groove 16 is oxidized (converted to SiO), and easily reacts with a hydrofluoric acid (HF) aqueous solution used in a cleaning process performed after the ashing process. Then, the side wall of the groove 16 is etched, and the diameter of the groove 16 is increased as shown in FIG. 5A, or the groove 16 becomes a bowing shape as shown in FIG. A dimensional conversion difference occurs, causing a short circuit between wirings.
Further, there has been a problem that the dielectric constant is increased by converting the interlayer insulating film 13 into SiO.
[0010]
In particular, when a porous film is used for the interlayer insulating film 13, since O plasma is deeply eroded and easily eroded, the amount of generated pores increases and the SiO 16 becomes thicker. The difference and the increase in the dielectric constant of the interlayer insulating film 13 have been problems.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, a first method for removing a resist pattern according to the present invention is a method for removing a resist pattern used as a mask for pattern etching of an insulating film from above the insulating film by ashing treatment by supplying oxygen plasma. This method is characterized in that ashing is performed on a resist pattern in a state where carbon is supplied together with supply of oxygen plasma.
[0012]
According to such a first method for removing a resist pattern, oxygen gas (O plasma) is supplied and ashing of the resist pattern is performed while carbon (C) is supplied. The excess O plasma reacts with the supplied C to generate a carbon-containing oxide, which is vaporized.
Thus, in order to prevent the side wall of the pattern-etched insulating film from being exposed to excessive O plasma, even if a low dielectric constant film having low resistance to O plasma is used as the insulating film, the O plasma is not applied to the insulating film. Erosion of the side wall can be prevented.
In addition, excess O plasma and C react with each other to generate and vaporize a carbon-containing oxide, so that oxidation of the sidewall of the pattern-etched insulating film by O plasma can be prevented.
[0013]
Further, a second resist pattern method of the present invention is a resist pattern removing method for removing a resist pattern used as a mask for pattern etching of an insulating film from the insulating film by ashing treatment by supplying oxygen plasma. After the first ashing of the resist pattern is performed by supplying oxygen plasma, the second ashing of the resist pattern is performed while carbon is supplied together with the supply of oxygen plasma.
[0014]
According to the second method for removing a resist pattern, the O plasma is supplied to perform the first ashing of the resist pattern, whereby the O plasma acts on the resist pattern made of an organic material, Reacts with C to form a carbon-containing oxide, and the resist pattern is removed by ashing.
[0015]
Then, at the end of the ashing process of the resist pattern, the amount of the O plasma for the ashing of the resist pattern decreases because the number of the resist patterns decreases, and as a result, the excess O plasma increases. In such an atmosphere, while the O plasma is supplied and the C is supplied, the second ashing process of the resist pattern is performed.
As a result, the excess O plasma reacts with the supplied C to generate and vaporize a carbon-containing oxide, thereby preventing the O plasma from eroding the side wall of the pattern-etched insulating film. Oxidation of the side wall of the insulating film due to this can be prevented.
Further, in the first ashing process, since the ashing process is performed by supplying O plasma, the ashing process can be performed promptly as compared with the second ashing process performed in a state in which C is supplied together with the supply of O plasma. it can.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the method for removing a resist pattern according to the present invention will be described in detail with reference to the drawings.
(1st Embodiment)
In the present embodiment, in a step of forming a Cu wiring by a groove wiring method, when an interlayer insulating film is pattern-etched to form a wiring groove, a connection hole, and the like, a resist pattern used as a mask is removed by ashing. The present invention is applied.
Note that the same components as those in the related art will be described with the same reference numerals.
[0017]
That is, as shown in FIG. 1A, an element is formed on a surface of a substrate 11 (for example, a silicon substrate) made of, for example, a silicon substrate, and a conductive layer is formed, and then, for example, silicon carbide (SiC) is formed on the substrate 11. An interlayer insulating film 13 made of, for example, silicon oxycarbide (SiOC), which is a low dielectric constant film, is formed via an etching stopper layer 12 made of.
Further, in order to prevent degassing from the interlayer insulating film 13 on the interlayer insulating film 13, SiO 2 ₂ After forming the protective film 14 made of, a resist 15 is applied on the protective film 14.
[0018]
Then, as shown in FIG. 1B, a resist pattern 15a is formed by a normal lithography process, and the protective film 14 and the interlayer insulating film 13 are pattern-etched by dry etching using the resist pattern 15a as a mask. Thus, a groove 16 such as a wiring groove or a connection hole is formed.
The groove 16 may have a stepped shape in which a connection hole is formed at the bottom of the wiring groove.
[0019]
After forming the groove 16 in this manner, an ashing process is performed to remove the resist pattern 15a above the interlayer insulating film 13.
First, a substrate 11 is loaded into a processing chamber (not shown) of a processing apparatus provided with a plasma generating means, for example, a parallel plate type plasma processing apparatus, and O 2 is added to a process gas. ₂ A gas containing carbon (C-containing gas) which easily reacts with O plasma and whose reaction product is easily vaporized is added to the process gas and supplied into the processing chamber 21 while using the gas. And perform a plasma discharge.
Thus, the ashing process of the resist pattern 15a is performed in a state where O plasma is supplied and C is supplied.
[0020]
Here, by using a parallel plate type plasma processing apparatus as the processing apparatus, O ₂ The plasma discharge is performed after the C-containing gas is added to the process gas and supplied into the processing chamber by using a gas. However, the present invention is not limited to this. And the ashing process may be performed while supplying the O plasma into the processing chamber and supplying the C-containing gas into the processing chamber.
[0021]
The ashing process here is preferably performed under reactive ion etching (RIE) conditions. As such a condition, for example, oxygen (O ₂ ) [Flow rate: 50cm ³ / Min] and methane (CH ₄ ) [Flow rate: 120cm ³ / Min] to the process gas, the bias power is set to 450 W, the pressure is set to 2.6 Pa, and the substrate temperature is set to 25 ° C.
Here, the gas flow rate indicates a volume flow rate in a standard state.
Here, it is preferable to perform the ashing process under the RIE condition because the anisotropic processing of the resist pattern 15a can be promoted by the ion assist effect.
[0022]
In this embodiment, as described above, C is supplied by adding a C-containing gas to the process gas.
Here, C is also supplied from the resist pattern 15a made of an organic material, but the amount is insufficient to prevent the O plasma from eroding the interlayer insulating film 13 forming the groove 16. According to the present invention, C is supplied from a source different from the resist pattern 15a.
[0023]
Here, CH is used as the C-containing gas. ₄ However, the present invention is not limited to this, and any gas containing C that easily reacts with O plasma and whose reaction product easily vaporizes may be used.
Examples of the C-containing gas include a gas containing O, nitrogen (N), and hydrogen (H) together with C.
Specifically, CO, CO ₂ , C ₅ H ₁₂ , C ₅ H ₁₀ , C ₄ H ₁₀ , C ₄ H ₈ , C ₄ H ₆ , C ₃ H ₉ N, C ₃ H ₈ , C ₃ H ₆ , C ₃ H ₄ , C ₂ N ₂ , C ₂ H ₇ N, C ₂ H ₆ , C ₂ H ₄ O, C ₂ H ₄ , COS, CH ₄ S, CHN, CH ₅ NCHN, CH ₅ N or a mixed gas thereof.
[0024]
Where O ₂ The flow ratio between the gas and the C-containing gas is appropriately set depending on the type of the C-containing gas to be added, the material of the interlayer insulating film 13, and the amount of the resist pattern 15a. However, the flow rate of the C-containing gas is preferably an amount that does not hinder the ashing process of the resist pattern 15a by the O plasma.
Also, O ₂ By adjusting the pressure during the ashing process without changing the flow rate of the gas, it is also possible to adjust the ratio of O plasma to C in the C-containing gas and C in the resist pattern 15a.
[0025]
Also, in the present embodiment, O ₂ Although an example in which the flow ratio of the gas and the C-containing gas is constant has been described, the present invention is not limited to this. For example, in the initial stage of the ashing process, the O plasma acts on the C constituting the resist pattern 15a. In order to reduce ₂ Since the flow ratio to the gas is reduced and the resist pattern 15a is reduced at the end of the ashing process, the C-containing gas ₂ The flow ratio to gas may be increased.
[0026]
By such ashing, O plasma acts on the resist pattern 15a made of an organic material, reacts with C constituting the resist pattern 15a to generate a carbon-containing oxide, and the resist pattern 15a is removed.
[0027]
Subsequently, as shown in FIG. 1C, the etching stopper layer 12 exposed at the bottom of the groove 16 is removed by etching, so that the groove 16 has a shape reaching the conductive layer on the substrate 11.
Thereafter, the inside of the groove 16 is cleaned using, for example, an HF aqueous solution as a processing liquid.
[0028]
Next, although not shown here, after a barrier metal film is formed on the protective film 14 so as to cover the inner wall of the groove 16, a Cu film is formed on the barrier metal film so as to fill the groove 16. Then, the Cu film and the barrier metal film on the protective film 14 are removed by a CMP method or the like, and a wiring or a via reaching the conductive layer of the substrate 11 is formed in the groove 16.
[0029]
According to such a method of removing a resist pattern, O.sub.2 is added to the process gas. ₂ While supplying O plasma using gas, CH gas is used as the process gas. ₄ Is added, and ashing is performed on the resist pattern 15a in a state where C is supplied. In the ashing, excessive O plasma reacts with the supplied C to form a carbon-containing oxide (eg, CO, CO). ₂ ) Is generated and vaporized.
This prevents the interlayer insulating film 13 forming the side wall of the groove 16 from being exposed to the O plasma, thereby suppressing the O plasma from eroding the side wall of the groove 16. For this reason, it is possible to prevent pores from being generated on the side wall of the groove 16.
[0030]
Therefore, the pores absorb moisture in the air, which inhibits film formation when the barrier metal film is formed on the inner wall of the groove 16, lowers the adhesion of the barrier metal film, peels off the film, and removes the interlayer insulating film. 13 can be prevented from having a high dielectric constant.
[0031]
Further, in order to prevent the interlayer insulating film 13 forming the side wall of the groove 16 from being oxidized by the O plasma and being turned into SiO, even when an HF aqueous solution is used as a processing liquid in the cleaning process after the ashing process, the groove 16 is formed. Etching of the side wall can be suppressed, and a dimensional conversion difference of the groove 16 can be suppressed.
Further, since the formation of SiO in the interlayer insulating film 13 is prevented, the dielectric constant of the interlayer insulating film 13 can be prevented from increasing.
[0032]
In the present embodiment, an example in which SiOC which is a low dielectric constant film is used for the interlayer insulating film 13 has been described, but the present invention is not limited to this.
However, it is preferable to use a low dielectric constant film having low oxygen plasma resistance as the interlayer insulating film 13 because the effects of the present invention can be remarkably exhibited.
As such a low dielectric constant film, as a material having a low dielectric constant, there is SiOC, SiOF, SiOCH or other organic insulating films. Further, as a porous film having a low dielectric constant, porous SiO 2 is used. ₂ Membrane, semi-porous SiO ₂ Membrane, porous HSSQ (Hydrogen Silsesquioxane) film, porous MSSQ (Hydrogen Silsesquioxane) film, porous tetrafluoroethylene film, porous SiOCH film, porous aromatic thermosetting resin (Porousaromatic thermoset) and the like.
In particular, when a porous film into which O plasma easily penetrates into the interlayer insulating film 13 is used, the method of removing a resist pattern according to the present embodiment can suppress the intrusion of O plasma. Can play.
[0033]
(2nd Embodiment)
Also in the present embodiment, an example will be described in which the resist pattern 15a used as a mask for pattern etching when forming the groove 16 is removed from above the interlayer insulating film 13 by ashing, as in the first embodiment.
As shown in FIG. 2, the processing apparatus used in the present embodiment is, for example, a parallel plate type plasma processing apparatus and includes a processing chamber 21 for performing an ashing process.
[0034]
The processing chamber 21 is provided with a stage 22 made of, for example, an electrostatic chuck for holding a substrate at the bottom thereof, and a plasma generating means 23 for supplying a gas into the processing chamber 21 at an upper portion thereof. A gas supply pipe 24 is provided.
[0035]
When performing the ashing process in this embodiment using such a processing apparatus, first, before performing the ashing process, for example, a C-containing gas is supplied from the gas supply pipe 24 into the processing chamber 21 to generate plasma. By performing the plasma discharge by the means 23, the C-containing substance 25 is deposited on, for example, the inner wall in the processing chamber 21.
Conditions for this deposition include, for example, ethane (C ₂ H ₆ ) [Flow rate: 15cm ³ / Min] and argon (Ar) [flow rate: 250 cm ³ / Min], the upper RF power is set to 1000 W, the lower bias power is set to 500 W, the pressure is set to 7.8 Pa, and the substrate temperature is set to 25 ° C.
[0036]
After depositing the C-containing material 25 in the processing chamber 21 as described above, the substrate 11 on which the resist pattern 15a is formed is again moved to the processing chamber 21 (see FIG. 1B). 2) (see FIG. 2), and ashing of the resist pattern 15a is performed.
As a condition for the ashing process, for example, O 2 ₂ [Flow rate: 200cm ³ / Min], a bias power of 150 W, a pressure of 3 Pa, and a substrate temperature of 25 ° C.
[0037]
According to such a method of removing the resist pattern, since the C is supplied from the C-containing material 25 deposited on the inner wall of the processing chamber (see FIG. 2) by the plasma discharge, the ashing processing of the resist pattern 15a is excessive. O plasma reacts with the supplied C, and carbon-containing oxide is generated and vaporized.
Accordingly, it is possible to prevent the O plasma from eroding the interlayer insulating film 13 forming the side wall of the groove 16 and suppress the formation of SiO in the interlayer insulating film 13, which is the same as in the first embodiment. The effect can be achieved.
Further, according to the resist pattern removing method of the present embodiment, even when supplying a very small amount of C, the amount of deposition of the C-containing material 25 (the area of the deposition region) in the processing chamber 21 can be adjusted. , C can be adjusted.
[0038]
(Third embodiment)
Also in the present embodiment, as in the first embodiment, an example will be described in which the resist pattern 15a used as a mask for pattern etching when forming the groove 16 is removed from above the interlayer insulating film 13 by ashing.
[0039]
In the ashing process according to the present embodiment, the same processing apparatus as that of the second embodiment is used, and as shown in FIG. A wall member 26 made of glassy carbon is arranged on the inner wall of the processing chamber 21.
Here, the wall material 26 made of glassy carbon is arranged. However, the present invention is not limited to this. The C-containing material may be arranged, and the stage 22 and the electrode on which the substrate 11 is placed may be arranged. A part made of a C-containing material such as silicon carbide (SiC) may be attached.
[0040]
In addition, the wall member 26 is arranged on the inner wall of the processing chamber 21. However, the present invention is not limited to this, and it is preferable that the wall member 26 is arranged in the processing chamber 21 near a region where plasma is generated by plasma discharge. .
Further, in order to supply C uniformly under an ashing process atmosphere, it is preferable to arrange C-containing materials evenly.
[0041]
Then, as shown in FIG. 1B again, the substrate 11 on which the resist pattern 15a is formed is placed on the stage 22 (see FIG. 3) in the processing chamber 21 (see FIG. 3), and the resist pattern is formed. The ashing process 15a is performed.
The conditions of the ashing process here are the same as in the second embodiment, and C is supplied by shaving the wall material 26 made of C-containing material by plasma discharge during the ashing process.
[0042]
Also according to such a method of removing the resist pattern, by supplying C from the wall material 26 made of the C-containing material disposed in the processing chamber 21, excessive O plasma is supplied to the ashing of the resist pattern 15a. Reacting with the C, and generating and vaporizing the carbon-containing oxide, it is possible to prevent the O plasma from eroding the interlayer insulating film 13 forming the side wall of the groove 16 and to prevent the O plasma from eroding. Since the formation of SiO can be suppressed, the same effects as in the first embodiment can be obtained.
Further, according to the resist pattern removing method of the present embodiment, since the C is supplied from the wall member 26 disposed on the inner wall of the processing chamber 21, the supply amount of C is adjusted by adjusting the surface area of the wall member 26. It is possible to adjust. Further, since it is possible to dispose a C-containing material composed of only C, it is easy to control the supply amount of C.
[0043]
(Fourth embodiment)
In the present embodiment, an example in which the ashing process of the resist pattern 15a used as a mask in the pattern etching when forming the groove 16 is performed in two stages will be described.
First, the substrate 11 is loaded into a processing chamber (not shown), and O plasma is supplied to perform a first ashing process.
[0044]
Here, the conditions for the ashing process are as follows. ₂ [Flow rate: 250cm ³ / Min], the bias power is set to 300 W, the pressure is set to 5 Pa, and the substrate temperature is set to 25 ° C.
[0045]
In the first ashing process, O plasma acts on the resist pattern 15a made of an organic material, reacts with C constituting the resist pattern 15a, and reacts with carbon-containing oxides (CO, CO). ₂ ) Is generated, and the resist pattern 15a is removed by ashing.
At the end of the ashing process, the amount of the O plasma for the ashing of the resist pattern 15a is reduced due to the decrease in the number of the resist patterns 15a. The second ashing process is performed in a state where C is supplied while C is supplied.
Specifically, when one type of carbon-containing oxide, for example, CO, generated by the O plasma reacting with C constituting the resist pattern 15a, is no longer detected by the endpoint detector installed in the processing chamber. Then, a second ashing process which is an over-etching process is started.
[0046]
The conditions for the second ashing process here include, for example, O 2 ₂ [Flow rate: 50cm ³ / Min] and CH ₄ [Flow rate: 120cm ³ / Min], the bias power is set to 450 W, the pressure is set to 2.6 Pa, and the substrate temperature is set to 25 ° C.
Here, the process gas is O ₂ And CH ₄ However, the present invention is not limited to this. ₂ It may be a mixed gas of a gas and a C-containing gas, or a gas containing C and O.
Specific examples of the C-containing gas include the C-containing gas described in the first embodiment.
[0047]
According to such a method of removing a resist pattern, in the first ashing process, O 2 gas is added to the process gas. ₂ Since the processing is performed using only the gas, the ashing processing of the resist pattern 15a can be performed quickly, and the time required for the ashing processing can be reduced.
Further, in the second ashing process, at the end of the ashing process, the O 2 plasma is used as a process gas in a state where the amount of the excess O plasma increases due to the decrease in the number of the resist patterns 15a. ₂ Since the ashing process is performed using C and a C-containing gas, excess O plasma reacts with C, and a carbon-containing oxide is generated and vaporized, so that the same effect as in the first embodiment can be obtained. it can.
[0048]
【The invention's effect】
As described above, according to the first method for removing a resist pattern of the present invention, an excess O plasma reacts with the supplied C to form a carbon-containing oxide during the ashing of the resist pattern. The vaporization can prevent the side wall of the pattern-etched insulating film from being exposed to O plasma.
Therefore, even when a low dielectric constant film having low resistance to O plasma is used for the insulating film, the O plasma can be prevented from eroding the side wall of the insulating film, and pores are formed on the side wall of the insulating film. It can be prevented from occurring.
In addition, excess O plasma reacts with the supplied C to generate and vaporize a carbon-containing oxide, thereby suppressing oxidation of the sidewall of the pattern-etched insulating film due to O plasma. In the cleaning step, the oxidized insulating film can be prevented from being removed, and the dimensional conversion difference of the pattern of the insulating film can be suppressed. Further, since the oxidation of the side wall of the insulating film is suppressed, the dielectric constant of the insulating film can be prevented from increasing.
[0049]
Further, according to the second method of removing a resist pattern of the present invention, the first ashing process of the resist pattern is performed by supplying O plasma, and thus the second method is performed in a state where C is supplied together with supply of O plasma. Ashing processing of a resist pattern can be performed more quickly than ashing processing.
Furthermore, at the end of the ashing process, the resist pattern is reduced, so that the O plasma is supplied in an atmosphere where excess O plasma is increased, and the second ashing process is performed in a state where C is supplied. Excessive O-plasma reacts with C to generate and vaporize a carbon-containing oxide, so that the sidewall of the pattern-etched insulating film can be prevented from being exposed to O-plasma.
Therefore, an effect similar to that of the first resist pattern removing method can be obtained.
[Brief description of the drawings]
FIG. 1 is a process sectional view for describing a first embodiment according to a method for removing a resist pattern of the present invention.
FIG. 2 is a processing apparatus for explaining a second embodiment according to the method for removing a resist pattern of the present invention.
FIG. 3 is a processing apparatus for explaining a third embodiment according to the method for removing a resist pattern of the present invention.
FIG. 4 is a cross-sectional view illustrating an example of a conventional method for removing a resist pattern.
FIG. 5 is a cross-sectional view for explaining a problem of a conventional method of removing a resist pattern.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 13 ... Interlayer insulating film, 15a ... Resist pattern, 16 ... Groove, 21 ... Processing chamber, 25 ... Carbon (C) content, 26 ... Wall material

Claims (8)

A method of removing a resist pattern used as a mask for pattern etching of an insulating film from the insulating film by an ashing process by supplying oxygen plasma,
An ashing process for the resist pattern in a state in which carbon is supplied together with the supply of the oxygen plasma; 2. The method according to claim 1, wherein the carbon is supplied as a carbon-containing gas. 2. The method according to claim 1, wherein a carbon-containing substance is deposited in a processing chamber for performing the ashing process before the ashing process is performed, and the carbon-containing material is used as a supply source of the carbon. 2. The method according to claim 1, wherein a carbon-containing substance is disposed in a processing chamber for performing the ashing processing, and the carbon-containing substance is used as a supply source of the carbon. 2. The method according to claim 1, wherein the insulating film is formed of a material having a lower dielectric constant than silicon oxide. 2. The method according to claim 1, wherein the insulating film is a porous film. A method for removing a resist pattern used as a mask for pattern etching of an insulating film, the resist pattern being removed from the insulating film by an ashing process by supplying oxygen plasma,
After performing a first ashing process on the resist pattern by supplying the oxygen plasma,
A method of removing a resist pattern, comprising performing a second ashing process on the resist pattern in a state where carbon is supplied together with the supply of the oxygen plasma. The method according to claim 7, wherein the carbon is supplied as a carbon-containing gas.

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