JP7232135B2 - Dry etching method and device manufacturing method - Google Patents

Description

The present invention relates to a dry etching method for dry-etching a Ru film in a plasma atmosphere and a device manufacturing method, and more particularly to a method capable of always dry-etching a Ru film at a predetermined etching rate.

For example, in the manufacturing process of electronic components such as communication devices, there is a step of dry etching a Ru film formed on the surface of a substrate such as a silicon wafer to form a desired electrode pattern. It is known from patent document 1. In this method, a substrate is placed on a stage (substrate electrode) in a vacuum chamber, and an etching gas containing oxygen gas and halogen-containing gas is introduced into the vacuum chamber in a vacuum atmosphere. Then, high-frequency power is applied to an antenna coil arranged above a dielectric window (dielectric plate) provided on the upper wall of the vacuum chamber. Then, high-frequency power is introduced into the vacuum chamber through the dielectric window, a plasma atmosphere is generated in the vacuum chamber, and the Ru film is dry-etched (etching process). During the dry etching of the Ru film, reaction products adhere to components such as the dielectric window which are present in the vacuum chamber. For this reason, a cleaning gas such as ammonia gas or other halogen-containing gas is introduced into the vacuum chamber periodically to generate a plasma atmosphere to clean the parts in the vacuum chamber (cleaning process).

Here, it has been found that, for example, as the area of the Ru film to be dry-etched increases as the area of the substrate increases, the etching rate gradually decreases even if the cleaning process is periodically performed. Therefore, the present inventors have made intensive studies and have come to the following findings. That is, when the Ru film is dry-etched as described above, RuO ₄ is usually produced mainly as a reaction product, and RuO ₄ has a high vapor pressure. Therefore, even if it adheres to parts in the vacuum chamber, it volatilizes and is evacuated. On the other hand, when the area of the Ru film to be dry-etched increases, not only RuO ₄ but also RuO ₂ is generated as a reaction product for some reason, and it has been found that this adheres to the inside of the vacuum chamber.

RuO ₂ has a low vapor pressure and is electrically conductive. For this reason, RuO ₂ adhering to parts in the vacuum chamber volatilizes and is not evacuated unlike RuO ₄ . When RuO ₂ having such conductivity adheres to the dielectric window, the introduction of a predetermined high-frequency power into the vacuum chamber is hindered, resulting in a gradual decrease in plasma density and an etching rate. It is thought that it will decline.

Japanese Patent Application Laid-Open No. 2004-247553 (see claim 5)

The present invention has been made based on the above findings, and efficiently removes RuO ₂ that is generated as a reaction product and adheres to parts existing in a vacuum chamber, and always dry-etches the Ru film in the same atmosphere. It is an object of the present invention to provide a dry etching method and a device manufacturing method that can be used.

In order to solve the above problems, the dry etching method of the present invention includes placing a substrate having a Ru film in a vacuum chamber, and introducing an etching gas containing oxygen gas and halogen-containing gas into the vacuum chamber having a vacuum atmosphere. , an etching step of dry-etching the Ru film in a plasma atmosphere, and a cleaning step of introducing a cleaning gas into the vacuum chamber and cleaning the parts existing in the vacuum chamber in the plasma atmosphere, wherein the cleaning gas is The etching gas includes a halogen-containing gas and a rare gas, and is characterized in that at least ions of the rare gas ionized in the plasma atmosphere are drawn into the parts existing in the vacuum chamber. At this time, if the component is a dielectric window provided on the wall of the vacuum chamber, a high-frequency voltage may be applied to an electrode placed close to the dielectric window in the cleaning step.

According to the present invention, when the etching process is performed, depending on the area of the Ru film to be dry-etched, reaction products such as RuO ₄ and RuO ₂ adhere to parts existing in the vacuum chamber. In order to remove such reaction products, a cleaning process is periodically performed while dry etching the Ru films on a plurality of substrates. At this time, a cleaning gas containing a halogen-containing gas and a rare gas is used so that at least the ions of the rare gas ionized in the plasma atmosphere are drawn into the parts existing in the vacuum chamber, thereby cleaning the parts in the vacuum chamber. Adhered RuO ₂ , which is originally volatilized and difficult to evacuate, can be efficiently removed.

Taking as an example a case where the component in the vacuum chamber is a dielectric window provided on the wall of the vacuum chamber, halogen ions ionized in the plasma atmosphere reduce RuO ₂ adhering to the dielectric window. Ru. At this time, by applying a high-frequency voltage to the electrode, ions of the rare gas ionized in the plasma atmosphere are drawn toward the dielectric window, and the impact of the ions of the rare gas on the reduced Ru causes Ru is discharged into the vacuum chamber and evacuated. Incidentally, when a cleaning gas containing a rare gas (not including a halogen-containing gas) or a cleaning gas containing a halogen-containing gas (not including a rare gas) is used, RuO ₂ cannot be effectively removed, and the etching process cannot be performed. It was confirmed that it was not possible to suppress the decrease in the etching rate that accompanies the implementation.

As described above, in the present invention, RuO ₂ that is produced as a reaction product and that adheres to the parts existing in the vacuum chamber is also efficiently removed. Then, in the case of introducing high-frequency power into the vacuum chamber through the dielectric window to generate a plasma atmosphere in the vacuum chamber, the cleaning process that is periodically carried out removes particles adhering to the dielectric window. By removing RuO ₂ , the introduction of high-frequency power is prevented from being hindered, and the Ru film can always be dry-etched in the same atmosphere (for example, with a predetermined etching rate maintained).

In the present invention, it is preferable that the cleaning gas further contains oxygen gas, and the flow rate ratio between the halogen-containing gas and the oxygen gas is set in the range of 10:0.1 to 1:1. By further containing oxygen gas within this flow ratio range, the oxygen ions ionized in the plasma atmosphere oxidize the Ru reduced by the halogen ions, volatilizing as RuO ₄ , so that RuO ₂ is more efficiently produced. can be removed. If the flow rate ratio of the halogen-containing gas and the oxygen gas is greater than 1:1, the oxygen ions become too large, and reduction by the halogen ions does not occur efficiently. As a result, RuO ₂ cannot be efficiently removed. may not be possible.

In the present invention, it is preferable that the ratio of the rare gas to the total flow rate of the cleaning gas is set to 2 to 20%. If the proportion of the rare gas is less than 2%, the halogen-containing gas will not be efficiently ionized (dissociated), and reduction by halogen ions will not occur efficiently. RuO ₂ may not be removed efficiently because Ru is not released efficiently either. On the other hand, if the proportion of the rare gas is more than 20%, the number of rare gas ions is too large, and reduction by halogen ions does not occur efficiently, so RuO ₂ may not be removed efficiently.

In the present invention, the halogen-containing gas preferably contains at least one selected from _Cl2 , _BCl3 , HCl, HBr, HI and _SiCl4 .

In the present invention, the halogen-containing gas preferably contains boron atoms or hydrogen atoms. According to this, the boron ions or hydrogen ions ionized in the plasma atmosphere during cleaning can efficiently reduce the RuO ₂ adhering to the parts to Ru, volatilize as RuO ₄ as described above, and evacuate. Therefore, RuO ₂ can be removed more efficiently, which is advantageous.

Further, in order to solve the above-described problems, the device manufacturing method of the present invention includes placing a substrate having a Ru film in a vacuum chamber, and placing an etching gas containing an oxygen gas and a halogen-containing gas in the vacuum chamber having a vacuum atmosphere. and an etching step of dry etching the Ru film in a plasma atmosphere, and a cleaning step of introducing a cleaning gas into the vacuum chamber and cleaning the parts existing in the vacuum chamber in the plasma atmosphere. The gas contains the same halogen-containing gas contained in the etching gas and a rare gas, and at least the ions of the rare gas ionized in the plasma atmosphere are attracted to the parts existing in the vacuum chamber, and at a predetermined timing. The cleaning step is performed. In the present invention, the predetermined timing includes not only the case where the etching process and the cleaning process are alternately performed, but also the case where the etching process is performed every time the etching process is performed a plurality of times.

1 is a cross-sectional view schematically illustrating the configuration of a dry etching apparatus capable of implementing the dry etching method of the embodiment of the present invention; FIG. FIG. 4 is a plan view showing electrodes placed close to a dielectric window; The graph which shows the experimental result which confirms the effect of this invention. The graph which shows the experimental result which confirms the effect of this invention. The graph which shows the experimental result which confirms the effect of this invention. The graph which shows the experimental result which confirms the effect of this invention.

Hereinafter, with reference to the drawings, dry etching of a Ru film of a silicon substrate such as a silicon wafer (hereinafter referred to as "substrate Sw") provided with a Ru film will be taken as an example, and the dry etching method and device according to the embodiment of the present invention will be described. A manufacturing method will be described.

Referring to FIG. 1, EM is an ICP (inductively coupled plasma) type dry etching apparatus that performs an etching process and a cleaning process included in the device manufacturing method and dry etching method of the present embodiment. The EM comprises a cylindrical vacuum chamber 1 with an upper opening 1a. Hereinafter, terms indicating directions such as "upper" and "lower" will be described based on the posture of the etching apparatus EM in FIG.

An upper opening 1 a of the vacuum chamber 1 is closed with a dielectric window 11 made of a quartz plate, and this dielectric window 11 constitutes the upper wall of the vacuum chamber 1 . A flange 1b projecting radially outward is provided on the upper side wall of the vacuum chamber 1, and the flange 1b and the dielectric window 11 are separated by an O-ring 12 fitted in a groove formed on the upper surface of the flange 1b. Sealed. A stage 2 is provided at the bottom of the vacuum chamber 1 via an insulator 13 . Although not shown, the stage 2 is composed of a metal base and a chuck plate provided on the base, and can electrostatically attract the substrate Sw while it is positioned with the Ru film facing upward. It's like The stage 2 is connected to the output from the high-frequency power supply E1, and by applying high-frequency power to the stage 2, a bias potential can be applied to the substrate Sw. Although not shown, the base of the stage 2 is provided with a heater and a coolant channel for circulating a coolant so that the substrate Sw can be controlled at a predetermined temperature.

An exhaust pipe 3 leading to a vacuum pump (not shown) is connected to the bottom of the vacuum chamber 1 so that the inside of the vacuum chamber 1 can be evacuated. A side wall of the vacuum chamber 1 is connected to a gas introduction pipe 4 leading to each gas source through a flow control valve (for example, a mass flow controller) (not shown). can be introduced with

A plurality of stages (two stages in this embodiment) of loop-shaped antenna coils 5 are provided above the dielectric window 11 . The antenna coil 5 is connected to the output of the high-frequency power source E2, so that the high-frequency power for forming the plasma atmosphere can be supplied to the antenna coil 5, so that the high-frequency power can be introduced into the vacuum chamber 1 through the dielectric window 11. there is

An electrode 6 is arranged between the dielectric window 11 and the antenna coil 5 in close proximity to the dielectric window 11 . Referring also to FIG. 2, the electrode 6 includes, for example, a base portion 61 and a plurality of main branches (six in this embodiment) extending radially from the base portion 61 so as to be point symmetrical with the base portion 61 as the starting point. It is possible to use a branch portion 63 that is configured by a portion 62 and a branch portion 63 that protrudes from the main branch portion 62 and divides a space defined by the main branch portions 62 adjacent to each other into a plurality of portions.

An output from a high frequency power supply E2 is connected to the electrode 6 via a variable capacitor 7. When a high frequency voltage is applied to the electrode 6 while a plasma atmosphere is formed in the vacuum chamber 1, ionization occurs in the plasma atmosphere. ions are drawn toward the dielectric window 11 . As the variable capacitor 7, for example, one whose capacitance is variable in the range of 10 pF to 500 pF can be used. A capacitor having a fixed capacitance can be used instead of the variable capacitor 7 .

The dry etching apparatus EM is equipped with a control means having a well-known microcomputer, sequencer, etc. (not shown). It is designed to The dry etching method of this embodiment for etching the Ru film formed on the substrate Sw using the dry etching apparatus EM will be described below.

First, the vacuum pump is operated to evacuate the inside of the vacuum chamber 1, and the substrate Sw is placed on the stage 2 using a transfer robot (not shown). It is electrostatically attracted. An etching gas containing a halogen-containing gas and an oxygen gas is introduced into the vacuum chamber 1 through the gas introduction pipe 4 . As the halogen-containing gas, at least one selected from Cl ₂ , BCl ₃ , HCl, HBr, HI and SiCl ₄ can be used. Each is set to 600 sccm (the pressure in the vacuum chamber 1 at this time is 1 to 20 Pa). Next, a plasma atmosphere is formed in the vacuum chamber 1 by applying high frequency power of 500 W to 2000 W, for example, of 13.56 MHz to the antenna coil 5 from the high frequency power supply E2. At the same time, high-frequency power of 30 W to 300 W, for example, of 12.56 MHz is applied to the stage 2, and a bias potential is applied to the substrate Sw. Etched (etching process). The end point of the etching process can be detected by a known method such as endpoint. When the end point of the etching process is detected, the introduction of the etching gas and the power supply are stopped to end the etching, and the processed substrate Sw is unloaded from the vacuum chamber 1 . After that, the next substrate Sw is placed on the stage 2 in the same manner as described above, and the Ru film is dry-etched.

When such an etching process is carried out, depending on the area of the Ru film to be dry etched, reaction products such as RuO ₄ and RuO ₂ adhere to parts such as the dielectric window 11 in the vacuum chamber 1 . In order to remove the reaction product adhering to the dielectric window 11, a cleaning process is periodically performed at a predetermined timing while the Ru films of the plurality of substrates Sw are dry-etched. Here, the timing of performing the cleaning can be appropriately set according to the etching conditions and the like. may be implemented.

In the cleaning process, a cleaning gas containing a halogen-containing gas and a rare gas is introduced into the vacuum chamber 1, high-frequency power of 300 W to 3000 W, for example, of 13.56 MHz is supplied from the high-frequency power source E2 to the antenna coil 5, and the high-frequency power source E1 A plasma atmosphere is formed in the vacuum chamber 1 by applying 5 W to 100 W of high frequency power of 12.56 MHz, for example, to the stage 2 . By using the same halogen-containing gas as that contained in the etching gas, it is possible to suppress changes in the atmosphere between the etching process and the cleaning process (which may lead to a decrease in device yield). A dummy substrate can be placed on the stage 2 during the cleaning process. The flow rate of the halogen-containing gas is set in the range of 10-200 sccm, and the flow rate of the rare gas is set in the range of 2-40 sccm (at this time, the pressure in the vacuum chamber 1 is 1-20 Pa).

When the plasma atmosphere is formed in this way, the RuO ₂ adhering to the dielectric window 11 is reduced to Ru by ions of the rare gas ionized in the plasma atmosphere. At this time, by applying a high-frequency voltage (for example, 100 to 5000 V) to the electrode 6 arranged close to the dielectric window 11, ions of the rare gas ionized in the plasma atmosphere are attracted toward the dielectric window 11. , Ru is discharged into the vacuum chamber 1 and evacuated by the impact (sputtering) of the rare gas ions on the Ru reduced by the halogen ions.

Here, it is preferable to set the ratio of the rare gas to the total flow rate of the cleaning gas to 2 to 20%. If the proportion of the rare gas is less than 2%, the halogen-containing gas is not efficiently ionized (dissociated), and the reduction of RuO ₂ by halogen ions does not occur efficiently. RuO ₂ may not be efficiently removed because Ru is not released efficiently due to the impact of . On the other hand, if the ratio of the rare gas is more than 20%, the number of rare gas ions is too large, and reduction by halogen ions does not occur efficiently, so RuO ₂ may not be removed efficiently.

Here, when a cleaning gas made of a rare gas (not including a halogen-containing gas) or a cleaning gas made of a halogen-containing gas (not including a rare gas) is used, RuO ₂ cannot be effectively removed, and the etching step It was confirmed by an experiment described later that the decrease in the etching rate due to the implementation of the above cannot be suppressed. On the other hand, in the present embodiment, it is presumed that the cleaning gas also contains a halogen-containing gas, thereby promoting the ionization of the noble gas in the plasma atmosphere and effectively removing RuO ₂ .

As described above, in this embodiment, RuO ₂ which is produced as a reaction product of dry etching and attached to the dielectric window 11 is also efficiently removed. When high-frequency power is introduced into the vacuum chamber 1 through the dielectric window 11 to generate a plasma atmosphere in the vacuum chamber 1, the dielectric window 11 is cleaned during a periodic cleaning process. By removing the RuO ₂ adhering to the RuO 2 , the introduction of high-frequency power into the vacuum chamber 1 is prevented from being hindered, and Ru The film can be dry etched.

Moreover, it is preferable that the cleaning gas further contains oxygen gas, and the flow rate ratio of the halogen-containing gas and the oxygen gas is set in the range of 10:0.1 to 1:1. By further containing oxygen gas within this flow ratio range, the oxygen ions ionized in the plasma atmosphere oxidize the Ru reduced by the halogen ions, volatilizing as RuO ₄ , so that RuO ₂ is more efficiently produced. can be removed. If the flow rate ratio of the halogen-containing gas and the oxygen gas is greater than 1:1, the oxygen ions become too large, and reduction by the halogen ions does not occur efficiently. As a result, RuO ₂ cannot be efficiently removed. may not be possible.

Further, it is preferable to use a halogen-containing gas containing a boron atom or a hydrogen atom. According to this, the boron ions or hydrogen ions ionized in the plasma atmosphere during cleaning can efficiently reduce the RuO ₂ adhering to the dielectric window 11 to Ru, and volatilize it as RuO ₄ as described above. Since the chamber can be evacuated with a vacuum, RuO ₂ can be removed more efficiently, which is advantageous.

Further, as the halogen-containing gas, a highly reducing first halogen-containing gas (for example, one containing no boron atoms such as _Cl2 ) and a second halogen-containing gas containing boron atoms (for example, _BCl3 ) are used. is preferably included. According to this, it is possible to prevent boron atoms from adhering to the dielectric window 11 during cleaning, and to enhance the effect of reducing RuO ₂ adhering to the dielectric window 11 to Ru. In this case, it is preferable that the flow rate of the first halogen-containing gas is higher than the flow rate of the second halogen-containing gas.

In order to confirm the effect of the above embodiment, the following experiment was conducted using the above dry etching apparatus EM. In Invention Experiment 1, a φ8-inch substrate Sw on which a Ru film having a thickness of 130 nm is formed (a resist pattern is formed on the Ru film, and the ratio of the area of the Ru film exposed from the resist opening to the surface area of the substrate Sw ( The opening ratio) was set to 90%) was placed on the stage 2, and after evacuating, the Ru film was dry-etched under the following etching conditions (etching process). That is, an etching gas containing oxygen gas and Cl ₂ gas was used, the oxygen gas flow rate was 320 sccm, the Cl ₂ gas flow rate was 60 sccm, the pressure was 1 Pa, the power supplied to the antenna coil 5 was 13.56 MHz, 800 W, The input power to stage 2 was set to 12.5 MHz and 60 W, respectively. When the end point of the etching process was detected using a known end point detector (EPD) provided in the dry etching apparatus EM, the introduction of the etching gas and power supply were stopped to complete the dry etching. In Experiment 1 of the present invention, the cleaning process was performed under the following cleaning conditions each time the etching process for 25 substrates Sw (one lot) was completed. That is, _a cleaning gas containing oxygen gas, Cl ₂ gas, and Ar gas was used. The input power was set at 13.56 MHz and 950 W, the power input to the stage 2 was set at 12.5 MHz and 20 W, and the cleaning time was set at 900 sec. FIG. 3 shows the relationship between the number of processed substrates Sw and the etching rate obtained by obtaining the etching rate from the time from the start of etching of each substrate Sw to the detection of the end point. According to this, it was confirmed that even when the number of processed wafers reached 175, the etching rate did not decrease and a constant etching rate (around 50 nm/min) could be achieved. From this, it was found that the Ru film can always be dry-etched in the same atmosphere by removing the RuO ₂ adhering to the dielectric window 11 .

In Invention Experiment 2, a φ8-inch substrate Sw on which a Ru film having a thickness of 130 nm was formed (a resist pattern was not formed on the Ru film, and the ratio of the exposed Ru film area to the surface area of the substrate Sw (aperture ratio) was set to 100%) was placed on the stage 2, and after evacuating, the Ru film was dry-etched under the following etching conditions (etching process). That is, an etching gas containing oxygen gas and Cl ₂ gas was used, the oxygen gas flow rate was 400 sccm, the Cl ₂ gas flow rate was 80 sccm, the pressure was 1 Pa, and the power supplied to the antenna coil 5 was 13.56 MHz, 800 W. The input power to stage 2 was set to 12.5 MHz and 150 W, respectively. In Experiment 2 of the present invention, the cleaning process was performed every time the etching process for one substrate Sw was completed (that is, the etching process and the cleaning process were alternately performed). The cleaning conditions were as follows: using a cleaning gas containing _Cl2 gas, _BCl3 gas and Ar gas, _Cl2 gas flow rate of 60 sccm, _BCl3 gas flow rate of 40 sccm, Ar gas flow rate of 10 sccm, pressure of 5 Pa, antenna The electric power applied to the coil 3 was set to 13.56 MHz, 950 W, the electric power applied to the stage 2 was set to 12.5 MHz, 20 W, and the cleaning time was set to 30 sec. FIG. 4 shows the results of obtaining the relationship between the number of processed substrates Sw and the etching rate in the same manner as in Invention Experiment 1 above. According to this, it was confirmed that a constant etching rate (approximately 47 nm/min) could be achieved while the ten substrates Sw were etched. As a result, even though the area of the Ru film to be dry-etched was larger than in Invention Experiment 1, the RuO ₂ adhering to the dielectric window 11 was removed, so that the Ru film was always etched in the same atmosphere. It was found that dry etching is possible.

In Comparative Experiment 1, the etching process and the cleaning process were performed in the same manner as in Inventive Experiment 1 above, except that Ar gas was not added to the cleaning gas. FIG. 5 shows the results of obtaining the relationship between the number of processed substrates Sw and the etching rate in the same manner as in Invention Experiment 1 above. According to this, it was confirmed that the etching rate abruptly decreased when the number of processed wafers reached 30 wafers. In Comparative Experiment 2, the etching process and the cleaning process were alternately performed in the same manner as in Inventive Experiment 2, except that Ar gas was not added to the cleaning gas. FIG. 6 shows the results of obtaining the relationship between the number of processed substrates Sw and the etching rate in the same manner as in Invention Experiment 2 above. According to this, it was confirmed that although a constant etching rate could be achieved for the second to seventh processed wafers, the etching rate abruptly decreased when the processed wafer number reached 10 wafers. Further, although not shown, in Comparative Experiment 3, the etching process and the cleaning process were performed in the same manner as in Invention Experiment 1 except that a cleaning gas consisting only of a rare gas (no oxygen gas or Cl ₂ gas) was used. bottom. Also in this case, similarly to the comparative experiment 1, it was confirmed that when the number of processed wafers reached 30, the etching rate decreased sharply. In these comparative experiments 1 to 3, _the RuO ₂ adhering to the dielectric window 11 could not be removed. As a result, the plasma density gradually decreased and the etching rate decreased. After the completion of Comparative Experiments 1 to 3, each dielectric window 11 was checked, and it was confirmed that RuO ₂ was thickly adhered especially to the central portion.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above, and can be modified as appropriate without departing from the scope of the technical idea of the present invention. For example, in the above embodiment, the case of removing RuO ₂ adhering to the dielectric window 11 has been described as an example, but the components present in the vacuum chamber 1 are not limited to the dielectric window 11, and RuO ₂ may be adhered. If there is a part in the vacuum chamber 1 that obstructs the atmosphere in the same manner as in the above, a high frequency voltage is applied to the part from a known high frequency power supply to attract ions of the rare gas ionized in the plasma atmosphere. good.

In the above embodiment, a high-frequency voltage is applied to the electrode 6 in order to draw ions of the rare gas into the dielectric window 11. However, the output of a known DC power supply is connected to the electrode 6, and a negative voltage is applied to the electrode 6. may be configured to be applied.

Sw... Substrate with Ru film, 1... Vacuum chamber, 11... Dielectric window (parts present in the vacuum chamber).

Claims (7)

an etching step of placing a substrate having a Ru film in a vacuum chamber, introducing an etching gas containing an oxygen gas and a halogen-containing gas into the vacuum chamber having a vacuum atmosphere, and dry etching the Ru film in a plasma atmosphere;
A dry etching method comprising a cleaning step of introducing a cleaning gas into the vacuum chamber and cleaning parts existing in the vacuum chamber in a plasma atmosphere,
The cleaning gas contains the same halogen-containing gas contained in the etching gas and a rare gas, and at least ions of the rare gas ionized in the plasma atmosphere are drawn into the parts existing in the vacuum chamber. and a dry etching method. 2. The dry etching method according to claim 1, wherein said component is a dielectric window provided in the vacuum chamber wall,
A dry etching method, wherein, in the cleaning step, a high-frequency voltage is applied to an electrode arranged close to a dielectric window. 3. The cleaning gas according to claim 1, wherein the cleaning gas further contains oxygen gas, and the flow rate ratio of the halogen-containing gas and the oxygen gas is set in the range of 10:0.1 to 1:1. dry etching method. 4. The dry etching method according to claim 1, wherein the ratio of the rare gas to the total flow rate of said cleaning gas is set to 2 to 20%. 5. The dry etching method according to claim 1, wherein said halogen-containing gas contains at least one selected from Cl ₂ , BCl ₃ , HCl, HBr, HI and SiCl ₄ . 5. The dry etching method according to claim 1, wherein said halogen-containing gas contains boron atoms or hydrogen atoms. an etching step of placing a substrate having a Ru film in a vacuum chamber, introducing an etching gas containing an oxygen gas and a halogen-containing gas into the vacuum chamber having a vacuum atmosphere, and dry etching the Ru film in a plasma atmosphere;
and a cleaning step of introducing a cleaning gas into the vacuum chamber and cleaning components existing in the vacuum chamber in a plasma atmosphere.
wherein the cleaning gas contains the same halogen-containing gas contained in the etching gas and a rare gas such that at least the ions of the rare gas ionized in the plasma atmosphere are attracted to the components present in the vacuum chamber;
A method of manufacturing a device, wherein the cleaning step is performed at a predetermined timing.

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