KR20180124773A - Plasma processing apparatus cleaning method - Google Patents

Abstract

The present invention relates to a method for cleaning a plasma processing apparatus. The objective of the present invention is to remove extraneous matter attached on a non-plasma surface of a plasma processing apparatus by predetermined plasma under a low pressure condition. The method for cleaning a plasma processing apparatus for performing plasma treatment on a substrate in a plasma processing chamber in a processing container comprises: a first step of taking out a plasma-processed substrate and insulating a part of a plasma processing chamber; a second step of generating plasma of a fluorocarbon gas in the plasma processing chamber; and a third step of removing extraneous matter on a non-plasma surface of an outer space by the plasma of the fluorocarbon gas supplied from the insulated area of the plasma processing chamber to a space outside the plasma processing chamber.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a plasma processing apparatus,

The present invention relates to a cleaning method of a plasma processing apparatus.

In the plasma processing apparatus, after a plasma-treated wafer is taken out, oxygen gas is introduced into a plasma processing chamber which is a plasma generating space, and a dry cleaning process is performed (see, for example, Patent Document 1). In Patent Document 1, the pressure of the plasma processing chamber is set to 26.7 Pa to 80.0 Pa, and a plasma of oxygen gas is generated to perform a dry cleaning process. Further, a carbon tetrafluoride gas is introduced into the plasma processing chamber to generate a plasma of a carbon tetrafluoride gas to carry out an oxide removing process.

(Prior art document)

(Patent Literature)

(Patent Document 1) Japanese Patent Laid-Open No. 2007-214512

However, in the dry cleaning method described above, it is difficult to remove the deposit adhered to the non-plasma region, because it is difficult to introduce plasma into the non-plasma region of the plasma processing apparatus located outside the plasma processing chamber. Particularly, in the above-mentioned dry cleaning method, it is difficult to introduce plasma into the non-plasma region under a low pressure condition necessary for removing deposits such as an oxide film.

In view of the above-mentioned problem, in one aspect, the present invention aims to remove adhering substances adhered to a non-plasma surface of a plasma processing apparatus by a predetermined plasma under a low pressure condition.

According to an aspect of the present invention, there is provided a cleaning method of a plasma processing apparatus for plasma processing a substrate in a plasma processing chamber in a processing vessel, the method comprising the steps of removing a plasma-processed substrate and inserting a region of a part of the plasma processing chamber A second step of generating a plasma of a fluorocarbon gas in the plasma processing chamber; a second step of generating plasma of the fluorocarbon gas supplied from the insulated region of the plasma processing chamber to a space outside the plasma processing chamber; And a third step of removing the deposits on the non-plasma surface of the outer space by the first step and the second step.

According to one aspect, it is possible to remove the deposit attached to the non-plasma surface of the plasma processing apparatus by a predetermined plasma under a low pressure condition.

1 is a view showing an example of a plasma processing apparatus according to an embodiment;
2 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the first embodiment;
3 is a view showing an example of opening and closing of a shutter according to an embodiment;
4 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the second embodiment;
5 is a view showing the relationship between pressure and high-frequency power during cleaning according to an embodiment;
6 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the third embodiment.
7 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the fourth embodiment.
8 is a diagram showing the relationship between pressure and high-frequency power at the time of cleaning according to an embodiment;

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, in the present specification and drawings, substantially the same constituent elements are denoted by the same reference numerals, and redundant description is omitted.

[Plasma Processing Apparatus]

First, a plasma processing apparatus according to an embodiment of the present invention will be described. 1 is an example of a plasma processing apparatus according to an embodiment of the present invention. The plasma processing apparatus according to the present embodiment has, for example, a substantially cylindrical processing vessel 2 made of aluminum whose surface is anodized. The processing vessel 2 is grounded.

A substantially columnar support base 4 is provided on the bottom of the processing vessel 2 through an insulating plate 3 such as ceramics. On the support table 4, a stage 5 holding the wafer W and functioning as a lower electrode is also provided.

A cooling chamber (7) is provided in the support base (4). A refrigerant is introduced into the cooling chamber (7) through the refrigerant introduction pipe (8). The refrigerant circulates through the cooling chamber (7) and is discharged from the refrigerant discharge pipe (9). A gas passage 14 for supplying a heat transfer medium (for example, He gas or the like) to the back surface of the wafer W is formed on the insulating plate 3, the support table 4, the stage 5, and the electrostatic chuck 11 , The cold heat of the stage 5 is transferred to the wafer W through the heat transfer medium, and the wafer W is maintained at a predetermined temperature.

Above the central portion on the upper side of the stage 5, an electrostatic chuck 11 having a circular shape and approximately the same diameter as the wafer W is provided. In the electrostatic chuck 11, the adsorption electrode 12 is disposed between the insulating materials. The DC power source 13 is connected to the attracting electrode 12 and a DC voltage is applied from the DC power source 13 to electrostatically attract the wafer W to the electrostatic chuck 11 by Coulomb force.

A ring-shaped focus ring 15 is disposed on the upper periphery of the stage 5 so as to surround the wafer W mounted on the electrostatic chuck 11. The focus ring 15 is made of a conductive material such as silicon and has an action of improving plasma uniformity. The side surface of the stage 5 is covered with the stage side cover member 60.

Above the stage 5, a gas showerhead 40 is provided. The gas showerhead 40 is provided opposite to the stage 5 functioning as a lower electrode and also functions as an upper electrode. The gas showerhead 40 is supported on the ceiling portion of the processing vessel 2 with the insulating material 41 interposed therebetween. The gas showerhead 40 has an electrode plate 24 and an electrode support 25 of a conductive material for supporting the electrode plate 24. The electrode plate 24 is made of, for example, a conductive material such as silicon or SiC or a semiconductor, and has a plurality of gas holes 45. The electrode plate (24) forms a surface facing the stage (5).

A gas introduction port 26 is provided at the center of the electrode support 25 and a gas supply pipe 27 is connected to the gas introduction port 26. The process gas supply source 30 is connected to the gas supply pipe 27 via an on-off valve 28 and a mass flow controller (MFC) The processing gas supply source 30 supplies a processing gas for plasma processing such as etching or a cleaning gas for cleaning processing. The gas is flow-controlled by a mass flow controller (MFC) 29 and is transferred to the gas diffusion chamber 44 through the gas supply pipe 27 and the gas introduction port 26 in accordance with the opening and closing of the opening / closing valve 28 . The gas is diffused in the gas diffusion chamber 44 and introduced into the interior of the processing vessel 2 from the plurality of gas holes 45.

The processing vessel 2 may be provided with a deposition shield 23 for preventing adhesion of reaction products generated during plasma processing such as etching to the inner wall thereof. The deposition shield 23 may be provided in the exhaust space S2 on the outer periphery side of the support table 4 and the stage 5. [

Between the deposition shield 23 and the stage 5, a baffle plate 20 formed in a ring shape is provided. As the deposition shield 23 and the baffle plate 20, aluminum materials coated with ceramics such as alumina and yttria (Y ₂ O ₃ ) can be suitably used.

The baffle plate 20 has a function of regulating the flow of gas and uniformly exhausting gas from the plasma processing chamber S1 to the exhaust space S2. The plasma processing chamber S1 is a plasma generating space (plasma processing space) formed of a stage 5, a gas showerhead 40, a deposition shield 23, and a baffle plate 20. [ Inside the plasma processing chamber S1, a predetermined plasma is generated from the gas supplied from the gas showerhead 40, and a predetermined process is performed on the wafer W by the plasma.

A portion of the plasma processing chamber S1 is openable and closable by a shutter 22. [ The gate valve GV is opened and the shutter 22 is lowered by the driving of the lifter 55 to open the shutter 22. When the wafer W is transferred from the opening of the shutter 22 to the plasma processing chamber S1 Or the wafer W is taken out from the plasma processing chamber S1.

Under the baffle plate 20 below the processing space S1, an exhaust space S2 for exhausting is formed. As a result, invasion of the plasma into the exhaust space S2 on the downstream side of the baffle plate 20 can be suppressed.

The first high frequency power supply 51 generates a high frequency power HF for plasma generation. The first high frequency power source 51 generates a high frequency power HF having a frequency of 60 MHz, for example. The first high frequency power supply 51 is connected to the gas showerhead 40 through a matching device 52. [ The matching unit 52 is a circuit for matching the output impedance of the first high frequency power supply 51 with the input impedance of the load side (upper electrode side).

The second high frequency power supply 53 generates a high frequency bias power LF for attracting ions to the wafer W. The second high frequency power source 53 generates a high frequency bias power LF having a frequency of 20 MHz, for example. The second high frequency power supply 53 is connected to the stage 5 via a matching device 54. [ The matching device 54 is a circuit for matching the output impedance of the second high frequency power supply 53 with the input impedance of the load side (lower electrode side).

An exhaust pipe 31 is connected to the bottom of the processing container 2 and an exhaust device 35 is connected to the exhaust pipe 31. The exhaust device 35 has a vacuum pump such as a turbo molecular pump, and can evacuate the inside of the processing container 2 to a predetermined reduced-pressure atmosphere. A gate valve GV is provided on the side wall of the processing vessel 2, and the wafer W is carried into and out of the processing vessel 2 by opening and closing the gate valve GV.

The plasma processing apparatus is controlled by the control apparatus 100. The control apparatus 100 is a computer having a communication interface (I / F) 105, a CPU 110, a memory 115, and the like. The memory 115 stores a control program for controlling various kinds of plasma processing such as etching performed by the plasma processing apparatus by the CPU 110, a program for executing processing in each part of the plasma processing apparatus according to processing conditions, That is, the recipe is stored. The CPU 110 controls each part (lifter 55, exhaust device 35, DC power supply 13, first high frequency power supply 51) of the plasma processing apparatus by using a recipe or a control program stored in the memory 115, The second high frequency power source 53, the process gas supply source 30, and the like).

≪ First Embodiment >

[Cleaning Method of Plasma Treatment Apparatus]

Next, a cleaning method of the plasma processing apparatus having such a configuration will be described in order of the first to fourth embodiments. First, an example of a cleaning method of the plasma processing apparatus according to the first embodiment will be described with reference to Fig. 2 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the first embodiment.

Before the present process is started, the wafer W is in a state in which a predetermined plasma process such as etching or film formation is performed in the plasma processing apparatus. When the present process is started, the gate valve GV is opened under the control of the control device 100, the processed wafer W is taken out of the process container 2 (step S11), and the shutter 22 is opened Step S13). Step S13 is an example of a first step for insulating a part of the plasma processing chamber S1 in the processing vessel 2. [ In other words, in this embodiment and each of the later-described embodiments, by opening the shutter 22 provided inside the processing vessel 2, an insulated region can be formed in a part of the plasma processing chamber S1. That is, the opening portion of the shutter 22 corresponds to an insulated area of a part of the plasma processing chamber.

Next, carbon tetrafluoride gas is introduced from the gas showerhead 40 (step S15). Step S15 is an example of a second step of generating a plasma of the fluorocarbon gas introduced into the plasma processing chamber S1. In this embodiment, a carbon tetrafluoride gas (CF ₄ gas) is introduced as an example of the fluorocarbon gas. However, for introducing the gas it is not limited to a CF ₄ gas, CF ₄ gas, C ₄ F ₆ gas, C ₅ F ₈ gas and C ₆ F ₆ but may be at least any one of the gas.

Next, the oxide removal processing is executed under the control of the control device 100 (step S17). Specifically, the carbon tetrafluoride gas introduced in step S15 is supplied to the non-plasma space S3 and the exhaust space (non-plasma space) in the processing vessel 2 outside the plasma processing chamber S1 via an insulated area of a part of the plasma processing chamber S1 ) ≪ / RTI > Plasma of the supplied carbon tetrafluoride gas removes deposits such as a silicon oxide film adhered to the surfaces of the non-plasma space S3 and the exhaust space S2. Hereinafter, the surfaces of the non-plasma space S3 and the exhaust space S2 are referred to as " non-plasma surface ".

Next, the shutter 22 is closed (step S19), the fluorine ion or the like is discharged from the plasma processing apparatus by the exhaust device 35 (step S21), and the process is terminated.

3 (a), during the plasma processing of the wafer W, the shutter 22 is closed and the deposition shield 23, the baffle plate 20, the stage 5, and the gas showerhead 40 The processing gas is introduced into the plasma processing chamber S1, which is a closed space. The processing gas is converted or dissociated mainly by the high-frequency power HF in the plasma processing chamber S1, and a plasma is generated. The shutter 22 is at the same potential as the deposition shield 23 and the baffle plate 20 and is grounded. As a result, the generated plasma is confined in the upper portion of the wafer W in the plasma processing chamber S1, and the desired plasma processing is performed on the wafer W.

During the plasma processing, a reaction product such as a silicon oxide film (SiO _x ) is produced at the time of processing the wafer W and adhered to the inner wall of the plasma processing chamber S 1. A part of the reaction product is gradually attached to the nonplasma surface S3 of the non-plasma space S3 and the non-plasma surface of the exhaust space S2, which are the spaces outside the plasma processing chamber S1 surrounded by the deposition shield 23, the baffle plate 20 and the shutter 22 Goes.

Thus, in the cleaning method according to the present embodiment, not only the shutter 22 is opened and the reaction product adhered to the surface of the plasma processing chamber S1 is cleaned, but also the non-plasma space S3 and the non- The reaction product is cleaned and removed.

3, in the cleaning method according to the present embodiment, after the wafer W is subjected to the plasma treatment as shown in Fig. 3 (a), as shown in Fig. 3 (b) And the shutter 22 is opened. The shutter 22 opened when the wafer W after processing is removed may be left open without being closed. As described above, in this embodiment, the shutter 22, which shields the plasma, is in an open state even during cleaning, thereby creating an insulated region A in a part of the plasma processing chamber S1.

Thus, in this embodiment, by opening the shutter 22, an electrically floating insulating region A shown in Fig. 3 (b) is formed on the ground surface of the deposition shield 23 and the baffle plate 20 . In this case, since the processing vessel 2 outside the plasma processing chamber S1 is grounded and grounded, a potential difference is generated between the floating insulating region A and the ground plane of the processing vessel 2.

At the time of cleaning, carbon tetrafluoride gas is introduced into the plasma processing chamber S1, and a plasma of carbon tetrafluoride gas, which is a plasma for cleaning, is generated. Plasma of carbon tetrafluoride gas is directed to the non-plasma space S3 of the ground plane and the non-plasma plane of the exhaust space S2, passing through the insulating region A (opening of the shutter 22) having a higher potential than the non-plasma surface.

As described above, in the cleaning process of the plasma processing apparatus according to the first embodiment, by the potential difference between the opening of the shutter 22 and the non-plasma surface of the non-plasma space S3 and the non-plasma surface of the exhaust space S2, The electrical behavior to enter the space S2 side has been described. As a structural behavior of the plasma, opening of the shutter 22 at the time of cleaning causes spatial distortion in the interior of the processing container 2, and plasma is generated from the opening of the shutter 22 to the non- S2. As a result, the reaction products adhered not only to the plasma processing chamber S1 but also to the non-plasma surfaces of the non-plasma space S3 and the exhaust space S2 can be effectively cleaned and removed by exhausting.

≪ Second Embodiment >

[Cleaning Method of Plasma Treatment Apparatus]

Next, an example of a cleaning method of the plasma processing apparatus according to the second embodiment will be described with reference to Fig. 4 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the second embodiment. In the cleaning process of the plasma processing apparatus according to the second embodiment shown in Fig. 4, the same step numbers are attached to the same process steps as the cleaning process of the plasma processing apparatus according to the first embodiment shown in Fig. 2, The description will be omitted.

In other words, in the cleaning method of the plasma processing apparatus according to the second embodiment, after introduction of the carbon tetrafluoride gas in step S15, the inert gas in step S41 is introduced, and only the oxide removing process in step S17 is performed. Which is different from the cleaning method according to the embodiment.

In this embodiment, too, the shutter 22 is opened to make an insulating region A at the time of cleaning, and a part of the plasma of the carbon tetrafluoride gas and the inert gas is led from the plasma processing chamber S1 to the non-plasma space S3 and the exhaust space S2. In this embodiment, the plasma is introduced into the non-plasma space S3 and the exhaust space S2 by making the pressure unbalanced between the plasma processing chamber S1 and the non-plasma space S3 and the exhaust space S2.

Particularly, in this embodiment, by adding an inert gas to the carbon tetrafluoride gas, the plasma can be more effectively guided to the non-plasma space S3 and the exhaust space S2 by the penning effect.

The penning effect is a phenomenon in which discharging occurs at a lower voltage than when only two types of gas are charged and discharged. In other words, in the present embodiment, by supplying two kinds of gases of carbon tetrafluoride gas and inert gas, a discharge can be generated at a lower pressure than in the case of a single gas of carbon tetrafluoride gas by the penning effect, and plasma can be generated. For example, by adding the Ar gas to the CF ₄ gas, it is possible to generate plasma at low pressure than that of the single gas of CF ₄ gas.

The plasma for cleaning can be guided to the exhaust space S2 and the non-plasma space S3 when the cleaning is performed while the shutter 22 is closed as in the conventional case, unless the pressure in the plasma processing chamber S1 side in the processing vessel 2 is set to a considerably high pressure none.

For example, FIG. 5 shows the case where the plasma can be induced from the plasma processing chamber S1 to the non-plasma space S3 and the exhaust space S2 side by the symbol " o ", and the pressure and the high frequency power HF are shown in the table. Ar gas is added to the CF ₄ gas to generate plasma, and the cleaning is performed while the shutter 22 is closed as shown in Fig. 3 (a). In this case, as shown in Fig. 5A, when the high frequency power HF applied to the upper electrode is set to 1400 W and the pressure in the plasma processing chamber S1 is set to a high pressure of 150 mTorr (= 20.0 Pa), the plasma is supplied to the exhaust space S2 and the non- S3. Here, the high-frequency power LF applied to the lower electrode is 1400 W.

According to this, when the high frequency power HF is 1300 W or less, the plasma can not be led to the exhaust space S2 and the non-plasma space S3 even if the inside of the plasma processing chamber S1 is 150 mTorr. In addition, even if a high frequency power HF of 1400 W is applied, if the inside of the plasma processing chamber S1 is less than 150 mTorr, the plasma can not be led to the exhaust space S2 and the non-plasma space S3.

On the other hand, in order to clean the silicon oxide film (SiO _x ) or the silicon nitride film (SiN _x ) by plasma, it is preferable to set the inside of the plasma processing chamber S 1 to a pressure lower than 150 mTorr.

Thus, in the present embodiment, for example, Ar gas is added to the CF _x gas to generate plasma, and the shutter 22 is opened to perform cleaning as shown in Fig. 3 (b). 5B, when the high frequency power HF is 1100 W or more, even if the plasma processing chamber S1 is at a low pressure of 40 mTorr (= 5.33 Pa), the plasma is supplied to the exhaust space S2 and the nonplasma space S3 . Even if the high frequency power HF is less than 1100 W, the plasma can be guided to the exhaust space S2 and the non-plasma space S3 at a low pressure of 70 mTorr (= 9.33 Pa) or more when the plasma processing chamber S1 is 900 W or more. Even if the high frequency power HF is less than 900 W, the plasma can be led to the exhaust space S2 and the non-plasma space S3 if the plasma processing chamber S1 is 100 mTorr (= 13.33 Pa) or more.

Thus, by opening the shutter 22 at the time of cleaning to form the insulating region A and introducing two or more kinds of gases for cleaning, for example, even if the plasma processing chamber S1 is at a low pressure of 40 mTorr, Can be induced in the plasma space S3. This promotes ion etching and cleans and removes not only the plasma treatment chamber S1 but also the deposits of the reaction products attached to the non-plasma surfaces of the exhaust space S2 and the non-plasma space S3.

≪ Third Embodiment >

[Cleaning Method of Plasma Treatment Apparatus]

Next, an example of a cleaning method of the plasma processing apparatus according to the third embodiment will be described with reference to Fig. 6 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the third embodiment. In the cleaning process of the plasma processing apparatus according to the third embodiment shown in Fig. 6, the same step numbers are attached to the same process steps as the cleaning process of the plasma processing apparatus according to the first embodiment shown in Fig. 2, Simplify or omit the description.

The cleaning method of the plasma processing apparatus according to the third embodiment is different from the cleaning method according to the first embodiment in that after the step S11 of carrying out the wafer W, the dry cleaning processing of the steps S31 to S35 is added .

In other words, in the present embodiment, after it is taken out of the wafer W, introducing O ₂ gas (step S31), creating a plasma of O ₂ gas, and the plasma processing chamber dry cleaning treatment by a plasma of O ₂ gas in the S1 (Step S33). This removes the deposit of the silicon oxide film adhering to the wall surface of the plasma processing chamber S1.

The process of performing the dry cleaning process by the plasma of the O ₂ gas is an example of the fourth step of generating the plasma of the oxygen gas introduced into the plasma process chamber S 1. The fourth step is performed before the first step to the third step of steps S13 to S17.

Next, oxygen ions and the like are discharged using the exhaust device 35 (step S35), and the shutter 22 is opened similarly to the cleaning process according to the first embodiment (step S13). Next, carbon tetrafluoride gas is introduced (step S15), and deposits of the silicon oxide film deposited on the non-plasma surfaces of the plasma processing chamber S1, the exhaust space S2 and the non-plasma space S3 are removed (step S17). Next, the shutter 22 is closed (step S19), the fluorine ions and the like are discharged (step S21), and the present process is terminated.

As described above, according to the cleaning method of the plasma processing apparatus according to the third embodiment, first, the inside of the processing container 2 is dry-cleaned using oxygen plasma. For this reason, a member formed of silicon such as the gas showerhead 40 is oxidized by dry cleaning and becomes a new particle generation source. Thus, in the present embodiment, the adherence of the silicon oxide film attached to the non-plasma surface including the silicon oxide film of the new particle generation source is cleaned using the plasma of carbon tetrafluoride gas.

At this time, also in the present embodiment, the shutter 22 is opened after the cleaning by the oxygen plasma to make the insulating region A, and the plasma is induced in the non-plasma space S3 and the exhaust space S2. Thus, the deposits of the silicon oxide film adhering to the non-plasma surfaces of the non-plasma space S3 and the exhaust space S2 can be removed.

≪ Fourth Embodiment &

[Cleaning Method of Plasma Treatment Apparatus]

Next, an example of a cleaning method of the plasma processing apparatus according to the fourth embodiment will be described with reference to Fig. 7 is a flowchart showing an example of a cleaning process of the plasma processing apparatus according to the fourth embodiment. In the cleaning process of the plasma processing apparatus according to the fourth embodiment shown in Fig. 7, the same step numbers are attached to the same process steps as the cleaning process of the plasma processing apparatus according to the third embodiment shown in Fig. 6, Simplify or omit the description.

The cleaning method of the plasma processing apparatus according to the fourth embodiment is different from the cleaning treatment according to the third embodiment only in that step S41 for introducing an inert gas is added after step S15 for introducing carbon tetrafluoride gas .

In other words, in the present embodiment, after the wafer W is taken out, O ₂ gas is introduced (step S31), a plasma of O ₂ gas is generated, and a dry cleaning process is performed by the plasma of O ₂ gas S33).

Next, oxygen ions and the like are discharged using the exhaust device 35 (step S35), and the shutter 22 is opened similarly to the cleaning process according to the third embodiment (step S13). Next, an inert gas such as carbon tetrafluoride gas and Ar gas is introduced (steps S15 and S41), and deposits of the silicon oxide film deposited in the processing vessel 2 are removed (step S17). Next, the shutter 22 is closed (step S19), the fluorine ions and the like in the plasma processing chamber S1 are discharged (step S21), and the process is terminated.

As described above, according to the cleaning method of the plasma processing apparatus according to the fourth embodiment, first, dry cleaning is performed using oxygen plasma. For this reason, a member formed of silicon such as the gas showerhead 40 is oxidized by dry cleaning and becomes a new particle generation source. Thus, in this embodiment, the deposit of the silicon oxide film attached to the non-plasma surface including the silicon oxide film of the new particle generation source is cleaned by using the plasma of the carbon tetrafluoride gas and the inert gas.

At this time, also in the present embodiment, the shutter 22 is opened after the cleaning by the oxygen plasma to make the insulating region A, and the plasma is induced in the non-plasma space S3 and the exhaust space S2.

Further, in the present embodiment, by introducing a mixed gas of carbon tetrafluoride gas and inert gas, the plasma can be generated at a lower pressure than that of a single gas of carbon tetrafluoride gas by the penning effect.

For the silicon oxide film to be cleaned by plasma, a condition of low pressure is required. On the other hand, in the present embodiment, the adherence of the silicon oxide film adhering to the non-plasma surfaces of the non-plasma space S3 and the exhaust space S2 by the plasma of the gas mixture of the carbon tetrafluoride gas and the inert gas in the environment satisfying the low- Can be removed.

For example, by adding the Ar gas to the CF ₄ gas, it is possible to generate plasma at low pressure than that of the single gas of CF ₄ gas.

For example, in Fig. 8, the case where the plasma is successfully induced in the non-plasma space S3 and the exhaust space S2 is indicated by the symbol " o ". The asterisk in FIG. 8 (b) shows the process conditions at the time of cleaning the oxygen plasma in step S33 in FIG. An asterisk in FIG. 8 (a) shows a process condition at the time of cleaning oxygen plasma in step S33 in FIG.

Figure 8 (a) the shows the result when introducing a mixed gas of CF ₄ gas, Ar gas and O ₂ gas into the plasma processing chamber S1. Figure 8 (a) the shows the result when the only CF ₄ gas introduced into the plasma processing chamber S1. 8A and 8B show a case where the shutter 22 is closed and cleaning by oxygen plasma is performed.

When a mixed gas of CF ₄ gas, Ar gas and O ₂ gas is introduced into the plasma processing chamber S 1 shown in FIG. 8 (a), compared to the case where only the CF ₄ gas shown in FIG. 8 (b) The plasma can be induced in the non-plasma space S3 and the exhaust space S2.

8 (a), O ₂ gas is supplied in addition to CF ₄ gas and Ar gas. However, even if O ₂ gas is not supplied, The plasma can be induced in the plasma space S3 and the exhaust space S2.

The cleaning method of the plasma processing apparatus according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope of the present invention Do. The matters described in the plural embodiments can be combined within a range that does not contradict each other.

For example, in each of the above-described embodiments, the silicon oxide film is described as an example of the attachment attached to the wall surface of the plasma processing apparatus to be cleaned. However, the object to be cleaned according to the present invention is not limited to this, and may be, for example, an attachment of a silicon nitride film. In this case, a plasma of a fluorocarbon gas such as CF ₄ gas or a plasma of a fluorocarbon gas and an inert gas similar to the gas used for removing the deposit of the silicon oxide film described in each of the above embodiments can be used. The inert gas added to the fluorocarbon gas is not limited to Ar gas but may be He gas.

The object to be cleaned according to the present invention is not limited to this and may be, for example, an organic polymer-containing material of C _x H _y or C _x F _y . In this case, the gas used for removing the organic polymer-containing substance of C _x H _y or C _x F _y is preferably an oxygen-containing gas.

Specifically, when removing the organic polymer-containing substance of C _x H _y or C _x F _y , the following first to third steps are carried out.

In the first step, the shutter 22 is opened to insulate a region A of the plasma processing chamber S1. In the second step, a plasma of the oxygen-containing gas introduced into the plasma processing chamber S1 is generated. In the third step, the plasma of the oxygen-containing gas is supplied from the insulated region A of the plasma processing chamber S1 to the non-plasma surface, and the deposits adhering to the non-plasma surfaces of the non-plasma space S3 and the exhaust space S2 are removed.

Thereby, the organic polymer inclusion of C _x H _y or C _x F _y adhering to the non-plasma surface of the non-plasma space S 3 and the exhaust space S 2 can be removed. In the cleaning method of supplying the plasma of the oxygen-containing gas to the non-plasma surface and removing the organic polymer-containing substance of C _x H _y or C _x F _y , in step S15 of Fig. 2 and Fig. 6, An oxygen-containing gas may be introduced. 4 and FIG. 7, oxygen-containing gas and inert gas may be introduced instead of introducing the carbon tetrafluoride gas and the inert gas.

The shutter 22 may be opened even if it is not fully opened. The opening of the shutter 22 is electrically insulated and a predetermined potential difference is generated from the ground plane, so that the cleaning effect of the plasma of the present embodiment can be exerted. However, if the shutter 22 is expanded, plasma for cleaning is easily induced in the exhaust space S2 and the non-plasma space S3, which is preferable.

Further, in each of the above-described embodiments, the example in which the shutter 22 is moved up and down by the lifter 55 has been described. However, the cleaning treatment of the plasma processing apparatus according to the present invention is not limited to this, and the shutter 22 and the deposition shield 23 may be moved up and down by the lifter 55 integrally.

The plasma processing apparatus according to the present invention can be applied to a plasma processing apparatus such as an ALD (Atomic Layer Deposition) apparatus, a Capacitively Coupled Plasma (CCP), an Inductively Coupled Plasma (ICP), a Radial Line Slot Antenna, an Electron Cyclotron Resonance Plasma (ECR) ). ≪ / RTI >

In this specification, a wafer (semiconductor wafer) W is described as an example of a substrate. However, the substrate is not limited to this, and may be various substrates used for an LCD (Liquid Crystal Display) or an FPD (Flat Panel Display), a photomask, a CD substrate, a printed substrate, or the like.

2: Processing vessel
5: stage (lower electrode)
7: Cooling chamber
11: Electrostatic Chuck
15: Focus ring
20: Baffle plate
23: Deposition shield
22: Shutter
30: Process gas supply source
35: Exhaust system
40: gas shower head (upper electrode)
51: first high frequency power source
53: Second high frequency power source
100: Control device
S1: Plasma processing chamber
S2: Exhaust space
S3: non-plasma space

Claims (9)

A cleaning method of a plasma processing apparatus for plasma processing a substrate in a plasma processing chamber in a processing vessel,
A first step of insulating a part of the plasma processing chamber after carrying out the plasma-processed substrate,
A second step of generating a plasma of a fluorocarbon gas in the plasma processing chamber,
A third step of removing deposits on the non-plasma surface of the outer space by the plasma of the fluorocarbon gas supplied from the insulated region of the plasma processing chamber to a space outside the plasma processing chamber,
Wherein the plasma processing apparatus further comprises:
The method according to claim 1,
And a fourth step of generating a plasma of oxygen gas in the plasma processing chamber,
Wherein the first to third steps are performed after the fourth step
Cleaning method.
3. The method according to claim 1 or 2,
And introducing an inert gas before the third step.
The method of claim 3,
Wherein the inert gas is an Ar gas or a He gas.
3. The method according to claim 1 or 2,
And a shutter forming part of the plasma processing chamber is opened to insulate a part of the plasma processing chamber.
3. The method according to claim 1 or 2,
Wherein the deposit on the non-plasma surface to be removed in the third step is silicon oxide or silicon nitride.
3. The method according to claim 1 or 2,
Wherein the fluorocarbon gas is at least one of CF ₄ gas, C ₄ F ₆ gas, C ₅ F ₈ gas and C ₆ F ₆ gas.
A cleaning method of a plasma processing apparatus for plasma processing a substrate in a plasma processing chamber in a processing vessel,
A first step of insulating a part of the plasma processing chamber after carrying out the plasma-processed substrate,
A second step of generating a plasma of an oxygen-containing gas in the plasma processing chamber,
A third step of removing deposits on the non-plasma surface of the outer space by the plasma of the oxygen-containing gas supplied from the insulated area of the plasma processing chamber to a space outside the plasma processing chamber,
Wherein the plasma processing apparatus further comprises:
9. The method of claim 8,
Wherein the deposit on the non-plasma surface to be removed in the third step is an organic polymer-containing substance of C _x H _y or C _x F _y .

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