TW201909272A - Cleaning method of plasma processing device - Google Patents

Abstract

There is provision of a cleaning method of a plasma processing apparatus including a plasma treatment chamber for applying plasma treatment to a substrate. The method includes: insulating a part of plasma treatment chamber, generating plasma of fluorocarbon gas in the plasma treatment chamber, and removing deposits on a non-plasma surface of a space outside of the plasma treatment chamber, by the plasma of the fluorocarbon gas introduced from the plasma treatment chamber to the outside space.

Description

 Cleaning method of plasma processing device  

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

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

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-214512

However, in the dry cleaning method described above, it is difficult to introduce the plasma into the non-plasma region of the plasma processing apparatus located outside the plasma processing chamber, so that it is difficult to remove the adhering matter attached to the non-plasma region. In particular, in the dry cleaning method described above, it is difficult to introduce the plasma into the non-plasma region by removing the low pressure condition required for the deposit of the oxide film or the like.

In view of the above problems, in one aspect, an object of the present invention is to remove adhering substances adhering to a non-plasma surface of a plasma processing apparatus by a predetermined plasma under a low pressure condition.

In order to solve the above problems, according to one aspect, a cleaning method of a plasma processing apparatus is provided, which is a method for cleaning a plasma processing apparatus for treating a substrate plasma in a plasma processing chamber in a processing container, having: In the first step, after the substrate after the plasma treatment is carried out, a part of the plasma processing chamber is insulated; in the second step, a plasma of a carbon fluoride gas is generated in the plasma processing chamber; and the third The step of removing the non-plasma surface of the outer space by supplying the plasma of the carbon fluoride gas to the space outside the plasma processing chamber from the insulated region of the plasma processing chamber. Attachment.

According to one phase, the adhering matter attached to the non-plasma surface of the plasma processing apparatus can be removed by a predetermined plasma under low pressure conditions.

2‧‧‧Processing container

5‧‧‧ mounting table (lower electrode)

7‧‧‧Cooling room

11‧‧‧Electrostatic fixture

15‧‧‧ Focus ring

20‧‧‧Bubble board

23‧‧‧Deposition shading

22‧‧‧Baffle

30‧‧‧Processing gas supply

35‧‧‧Exhaust device

40‧‧‧ gas sprinkler (upper electrode)

51‧‧‧1st high frequency power supply

53‧‧‧2nd high frequency power supply

100‧‧‧Control device

S1‧‧‧ plasma processing room

S2‧‧‧Exhaust space

S3‧‧‧Non-plasma space

Fig. 1 is a view showing an example of a plasma processing apparatus according to an embodiment.

Fig. 2 is a flow chart showing an example of the washing process of the plasma processing apparatus according to the first embodiment.

Fig. 3 is a view showing an example of opening and closing of a shutter relating to an embodiment.

Fig. 4 is a flow chart showing an example of the washing process of the plasma processing apparatus according to the second embodiment.

Fig. 5 is a view showing the relationship between the pressure at the time of cleaning and the high frequency power according to the embodiment.

Fig. 6 is a flow chart showing an example of the washing process of the plasma processing apparatus according to the third embodiment.

Fig. 7 is a flow chart showing an example of the washing process of the plasma processing apparatus according to the fourth embodiment.

Fig. 8 is a view showing the relationship between the pressure at the time of cleaning and the high-frequency power according to the embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present specification and the drawings, the same components are denoted by the same reference numerals, and the description thereof will not be repeated.

[plasma processing device]

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

The bottom of the processing container 2 is passed through an insulating plate 3 made of ceramic or the like to provide a support column 4 having a substantially cylindrical shape. The support table 4 is provided with a mounting table 5 that holds the wafer W and also functions as a lower electrode.

A cooling chamber 7 is provided inside the support table 2. The cooling chamber 7 is introduced through the refrigerant introduction pipe 8 to introduce a refrigerant. The refrigerant circulates in the cooling chamber 7, and is discharged from the refrigerant discharge pipe 9. Further, the insulating plate 3, the support table 4, the mounting table 5, and the electrostatic chuck 11 are formed to supply a heat transfer medium (for example, He gas or the like) to the gas passage 14 on the inner surface of the wafer W, and the medium is transmitted through the heat transfer medium. The cold heat of the stage 5 is conducted to the wafer W to maintain the wafer W at a predetermined temperature.

An electrostatic chuck 11 having a circular shape and having a diameter slightly the same as that of the wafer W is provided on the upper central portion of the mounting table 5. The electrostatic chuck 11 places the adsorption electrode 12 between the insulating materials. The adsorption electrode 12 is connected to the DC power source 13. By applying a DC voltage from the DC power source 13, the wafer W can be adsorbed to the electrostatic chuck 11 by Coulomb force.

An annular focus ring 15 is disposed on the peripheral portion of the upper end of the mounting table 5 so as to surround the wafer W placed on the electrostatic chuck 11 . The focus ring 15 is formed of a conductive material such as tantalum and has the function of improving plasma uniformity. The side surface of the mounting table 5 is covered by the mounting table side covering member 60.

A gas shower head 40 is provided above the mounting table 5. The gas shower head 40 is disposed opposite to the mounting table 5 having a function as a lower electrode, and has a function as an upper electrode. The gas shower head 40 is supported by the top of the processing container 2 through the insulating material 41. The gas shower head 40 has an electrode plate 24 and an electrode support 25 that supports a conductive material of the electrode plate 24. The electrode plate 24 is made of, for example, conductive or semiconductor such as tantalum or SiC, and has a plurality of gas holes 45. The electrode plate 24 is formed to face the opposing surface of the mounting table 5.

A gas introduction port 26 is provided in the center of the electrode support body 25, and a gas supply pipe 27 is connected to the gas introduction port 26. The gas supply pipe 27 is connected to the process gas supply source 30 through the on-off valve 28 and the mass flow controller (MFC) 29. The processing gas supply source 30 supplies a processing gas for plasma treatment such as etching, a cleaning gas for cleaning processing, and the like. The gas is controlled by the mass flow controller (MFC) 29, and is conveyed to the gas diffusion chamber 44 through the gas supply pipe 27 and the gas introduction port 26 in response to opening and closing of the opening and closing valve 28. The gas diffuses in the gas diffusion chamber 44 and is introduced into the inside of the processing container 2 from the plurality of gas holes 45.

The processing container 2 is detachably provided with a deposition shielding portion 23 which is useful for preventing a reaction product generated during plasma treatment such as etching from adhering to the inner wall thereof. Further, the deposition shielding portion 23 can be provided in the exhaust space S2 on the outer peripheral side of the support table 4 and the mounting table 5.

A buffer plate 20 formed in an annular shape is provided between the deposition shielding portion 23 and the mounting table 5. The deposition shielding portion 23 and the buffer plate 20 can be suitably coated with a ceramic such as alumina or yttria (Y ₂ O ₃ ).

The baffle plate 20 has a function of adjusting the air flow and uniformly exhausting the gas from the plasma processing chamber S1 toward the exhaust space S2. The plasma processing chamber S1 is a plasma generating space (plasma processing space) formed by the mounting table 5, the gas shower head 40, the deposition shielding portion 23, and the buffer plate 20. Inside the plasma processing chamber S1, a predetermined plasma is generated from the gas supplied from the gas shower head 40, and the wafer W is subjected to a predetermined process by plasma.

A part of the plasma processing chamber S1 can be opened and closed by the baffle 22. When the wafer W is loaded and unloaded, the gate valve GV is opened, the shutter 55 is lowered by the driving of the lifter 55, and the shutter 22 is opened, and the wafer W is carried from the opening of the shutter 22 to the plasma processing. The chamber S1 or the wafer W is carried out from the plasma processing chamber S1.

Below the buffer plate 20 on the lower side of the processing space S1, an exhaust space S2 for exhausting is formed. Thereby, it is possible to suppress the plasma from intruding into the exhaust space S2 on the downstream side of the buffer plate 20.

The first high-frequency power source 51 generates high-frequency power HF for plasma generation. The first high-frequency power source 51 generates high-frequency power HF of, for example, a frequency of 60 MHz. The first high frequency power source 51 is connected to the gas shower head 40 through the matching unit 52. The matching unit 52 is a circuit for matching the input impedance of the first high-frequency power source 51 and the input impedance of the load side (upper electrode side).

The second high frequency power source 53 generates high frequency bias power LF for attracting ions to the wafer W. The second high-frequency power source 53 generates, for example, a high-frequency bias power LF of a frequency of 20 MHz. The second high-frequency power source 53 is connected to the mounting table 5 through the matching unit 54. The matching unit 54 is a circuit for matching the output impedance of the second high-frequency power source 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 is provided with a vacuum pump such as a turbo molecular pump, and the inside of the processing container 2 can be evacuated to a predetermined reduced pressure atmosphere. Further, the side wall of the processing container 2 is provided with a gate valve GV, and the wafer W is carried in and out of the processing container 2 by opening and closing of the gate valve GV.

The plasma processing apparatus is controlled by the control unit 100. The control device 100 is provided with 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 plasma processing such as etching performed by the plasma processing apparatus by the CPU, and a program for causing each part of the plasma processing apparatus to perform processing in accordance with the processing conditions. That is, the recipe is processed. The CPU 110 controls each part of the plasma processing apparatus using the recipe or control program stored in the memory 115 (the elevator 55, the exhaust unit 35, the DC power source 13, the first high-frequency power source 51, the second high-frequency power source 53, and the processing gas. Supply source 30, etc.).

<First embodiment>

[Washing method of plasma processing device]

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

Further, before the start of the process, the wafer W is in a state in which a predetermined plasma treatment such as etching or film formation is applied to the plasma processing apparatus. When the present process is started, the gate valve GV is opened by the control of the control device 100, and the processed wafer W is carried out from the processing container 2 (step S11), and the shutter 22 is opened (step S13). ). Step S13 is an example of the first step of insulating a part of the region of the plasma processing chamber S1 in the processing container 2. That is, in the present embodiment and the following embodiments, the region where the plasma processing chamber S1 is partially insulated can be opened by opening the shutter 22 provided inside the processing container 2. That is, the opening portion of the baffle 22 corresponds to an insulated region of a portion of the plasma processing chamber.

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

Next, the oxide removal processing is performed by the control of the control control 100 (step S17). Specifically, the carbon tetrafluoride gas introduced in step S15 is supplied to the non-plasma space S3 in the processing container 2 outside the plasma processing chamber S1 through the insulated region of a part of the plasma processing chamber S1. And the exhaust space (non-plasma space) S2. Then, the deposit of the ruthenium oxide film or the like adhered to the surface of the non-plasma space S3 and the exhaust space S2 is removed by the plasma of the supplied carbon tetrafluoride gas. Hereinafter, the surfaces of the non-plasma space S3 and the exhaust space S2 are also referred to as "non-plasma surfaces".

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

As shown in FIG. 3(a), the baffle 22 is closed during the plasma processing of the wafer W, and the processing gas is introduced into the deposition shield 23, the buffer plate 20, the mounting table 5, and the gas shower head. A plasma processing chamber S1 of 40 enclosed spaces. The process gas is mainly ionized or dissociated by the high frequency power HF in the plasma processing chamber S1 to generate a plasma. The baffle 22 has the same potential as the deposition shielding portion 23 and the buffer plate 20, and is at a ground potential. Thereby, the generated plasma is sealed above the wafer W in the plasma processing chamber S1, and the desired plasma treatment can be applied to the wafer W.

Further, during the plasma processing, when the wafer W is processed, a reaction product such as a ruthenium oxide film (SiOx) is formed and adhered to the inner wall of the plasma processing chamber S1. A part of the reaction product gradually adheres to the non-plasma space S3 of the outer space of the plasma processing chamber S1 surrounded by the deposition shielding portion 23, the buffer plate 20, and the baffle 22, and the non-plasma surface of the exhaust space S2. .

Therefore, in the cleaning method according to the present embodiment, the shutter 22 is opened, and not only the reaction product adhered to the surface of the plasma processing chamber S1 but also the non-plasma space S3 and the exhaust space S2 are cleaned. A reaction product attached to the plasma surface.

Referring to Fig. 3, in detail, in the cleaning method according to the present embodiment, as shown in Fig. 3(a), after the wafer W is plasma-treated, the processed crystal is as shown in Fig. 3(b). The circle W is carried out, and the shutter 22 is opened. The shutter 22 that is opened when the processed wafer W is carried out may be kept open without being closed. As described above, in the present embodiment, the baffle 22 that originally shields the plasma is still in an open state during cleaning, thereby creating a region A in which a part of the plasma processing chamber S1 is insulated.

In this manner, in the embodiment, the insulating region of the electrical floating surface as shown in FIG. 3(b) is formed with respect to the large ground of the deposition shielding portion 23 and the buffer plate 20 by opening the shutter 22. A. As a result, since the processing container 2 outside the plasma processing chamber S1 is grounded and becomes a ground potential, a potential difference is generated between the floating insulating region A and the large ground of the processing container 2.

At the time of cleaning, carbon tetrafluoride gas is introduced into the plasma processing chamber S1 to generate a plasma of a carbon tetrafluoride gas (cleaning plasma). The plasma of the carbon tetrafluoride gas is induced to the non-plasma space S3 and the exhaust space S2 of the large ground by the insulating region A (the opening of the baffle 22) whose potential is higher than that of the non-plasma surface. Non-plasma surface.

As described above, in the cleaning process of the plasma processing apparatus according to the first embodiment, the potential difference between the opening of the baffle 22 and the non-plasma space S3 and the non-plasma surface of the exhaust space S2 is obtained. The electrical action of sucking the plasma into the non-plasma space S3 and the exhaust space S2 side will be described. In addition, the action of the plasma structure causes a spatial skew in the interior of the processing vessel 2 by opening the baffle 22 during cleaning, and the plasma is directed from the opening of the baffle 22 toward the non-plasma space S3. The exhaust space S2 moves. Thereby, the reaction product adhering to the non-plasma surface of the non-plasma space S3 and the exhaust space S2 can be effectively cleaned not only in the plasma processing chamber S1 but also by exhaust gas.

<Second embodiment>

[Washing method of plasma processing device]

An example of the cleaning method of the plasma processing apparatus according to the second embodiment will be described with reference to Fig. 4 . Fig. 4 is a flow chart showing an example of the washing process of the plasma processing apparatus according to the second embodiment. In addition, the washing process of the plasma processing apparatus according to the second embodiment shown in FIG. 4 is the same as the washing process of the plasma processing apparatus according to the first embodiment shown in FIG. The step number is omitted and the description is omitted.

In other words, in the cleaning method of the plasma processing apparatus according to the second embodiment, after the introduction of the carbon tetrafluoride gas in the step S15, the introduction of the inert gas in the step S41 is performed, and then the oxide removal treatment in the step S17 is performed. The cleaning method differs from the first embodiment in that it is different.

In this embodiment, the baffle 22 is opened to clean the insulating region A, and a portion of the plasma of the carbon tetrafluoride and the inert gas is induced from the plasma processing chamber S1 to the non-plasma space S3. Exhaust space S2. In the present embodiment, the plasma is induced to the non-plasma space S3 and the exhaust space S2 by creating a pressure imbalance between the plasma processing chamber S1 and the non-plasma space S3 and the exhaust space S2. .

In particular, in the present embodiment, by further adding an inert gas to the carbon tetrafluoride gas, the plasma can be more effectively induced into the non-plasma space by the Penning effect. S3 and exhaust space S2.

The Penning effect refers to a phenomenon in which discharge can be generated with a voltage lower than that of a single gas when the two gases are sealed and discharged. In other words, in the present embodiment, by supplying two types of gases of a carbon tetrafluoride gas and an inert gas, a discharge can be generated by a Penne effect with a lower pressure than a single gas of a carbon tetrafluoride gas. To produce plasma. For example, by adding Ar gas to CF ₄ gas, it is possible to generate plasma in a lower pressure than in the case of a single gas of CF ₄ .

When the baffle 22 is continuously closed and cleaned as in the prior art, if the plasma processing chamber S1 side in the processing container 2 is not brought to a relatively high pressure, the plasma for cleaning cannot be induced to the exhaust space S2 and Non-plasma space S3.

For example, Fig. 5 indicates the time at which the plasma can be induced from the plasma processing chamber S1 toward the non-plasma space S3 and the exhaust space S2 by the symbol "○", and the pressure at this time and the high-frequency power HF. Displayed in the form. Ar gas was added to the CF ₄ gas to generate a plasma, and the baffle 22 was continuously closed as shown in Fig. 3 (a) for cleaning. In this case, as shown in FIG. 5(a), when the high-frequency power HF applied to the upper electrode is 1400 W and the plasma processing chamber S1 has a high pressure of 150 mTorr (= 20.0 Pa), the plasma can be used. It is induced to the exhaust space S2 and the non-plasma space S3. Here, the high frequency power LF system 1400W applied to the lower electrode.

Therefore, when the high-frequency power HF is 1300 W or less, even if the inside of the plasma processing chamber S1 is 150 mTorr, the plasma cannot be induced to the exhaust space S2 and the non-plasma space S3. Further, even when the high-frequency power HF of 1400 W is applied, when the plasma processing chamber S1 is less than 150 mTorr, the plasma cannot be induced to the exhaust space S2 and the non-plasma space S3.

On the other hand, since the silicon oxide film (SiO _x) or silicon nitride film (SiN _x) is a so-called low pressure plasma cleaning system requires the condition, it is desirably in the inner plasma processing chamber S1 is compared to a low pressure 150mTorr.

Then, in the present embodiment, for example, Ar gas is added to CF _x gas to generate a plasma, and the baffle 22 is opened as shown in Fig. 3 (b) for cleaning. Therefore, as shown in FIG. 5(b), the Penning effect can be as long as the high-frequency power HF is 1100 W or more, even if the plasma processing chamber S1 has a low pressure of 40 mTorr (=5.33 Pa). The plasma is induced to the exhaust space S2 and the non-plasma space S3. In addition, when the high-frequency power HF is less than 1100 W and is 900 W or more, the plasma can be induced to the exhaust space S2 and the non-plasma space by a low pressure of 70 mTorr (=9.33 Pa) or more in the plasma processing chamber S1. S3. Even if the high-frequency power HF is less than 900 W, the plasma can be induced into the exhaust space S2 and the non-plasma space S3 as long as the inside of the plasma processing chamber S1 is 100 mTorr (= 13.33 Pa) or more.

Thereby, the insulating region A can be formed by opening the shutter 22 during cleaning, and by introducing two or more types of cleaning gas, even in a low pressure state of, for example, 40 mTorr in the plasma processing chamber S1, The plasma can be induced to the exhaust space S2 and the non-plasma space S3. Thereby, ion etching is promoted, and not only the plasma processing chamber S1 but also the deposit of the reaction product adhered to the non-plasma surface of the exhaust space S2 and the non-plasma space S3 can be cleaned and removed.

<Third embodiment>

<Third embodiment>

[Washing method of plasma processing device]

Next, an example of the cleaning method of the plasma processing apparatus according to the third embodiment will be described with reference to Fig. 6 . Fig. 6 is a flow chart showing an example of the washing 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 steps as those in the cleaning process of the plasma processing apparatus according to the first embodiment shown in FIG. 2 are attached. Step numbers are numbered and simplified or omitted.

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

That is, in the present embodiment, after the wafer W is carried out, O ₂ gas is introduced (step S31) to generate O ₂ gas plasma, which is plasma-treated in the plasma processing chamber S1 by O ₂ gas plasma. A dry cleaning process is performed (step S33). Thereby, the deposit of the tantalum oxide film adhered to the wall surface of the plasma processing chamber S1 is removed.

Further, the treatment for performing the dry cleaning treatment by the O ₂ gas plasma generates an example of the fourth step of generating the oxygen plasma introduced into the plasma processing chamber S1. The fourth step is performed before the first step to the third step of steps S13 to S17.

Then, after the oxygen gas or the like is discharged by using the exhaust device 35 (step S35), the shutter 22 is opened in the same manner as the washing process according to the first embodiment (step S13). Next, the carbon tetrafluoride gas is introduced (step S15) to remove the deposits of the tantalum oxide film adhered to the non-plasma surface of the plasma processing chamber S1, the exhaust space S2, and the non-plasma space S3 (step S17). . Next, the shutter 22 is closed (step S19), and after the fluorine ions or the like are discharged (step S21), the processing is terminated.

As described above, according to the cleaning method of the plasma processing apparatus according to the third embodiment, the dry cleaning in the processing container 2 is first performed using the oxygen plasma. Therefore, the member formed by the gas shower head 40 or the like is oxidized by the dry cleaning, and becomes a new particle generation source. Therefore, in the present embodiment, the carbon tetrafluoride gas plasma is used together to clean the deposit of the tantalum oxide film containing the new particle generation source and the tantalum oxide film to which the non-plasma surface is attached.

At this time, in the present embodiment, after the oxygen plasma is cleaned, the baffle 22 is opened to form the insulating region A, and the plasma is induced into the non-plasma space S3 and the exhaust space S2. Thereby, the deposit of the cerium oxide adhered to the non-plasma surface of the non-plasma space S3 and the exhaust space S2 can be removed.

<Fourth embodiment>

[Washing method of plasma processing device]

Next, an example of the cleaning method of the plasma processing apparatus according to the fourth embodiment will be described with reference to Fig. 7 . Fig. 7 is a flow chart showing an example of a cleaning method 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 processing steps as those of the plasma processing apparatus according to the third embodiment shown in FIG. 6 are the same. Step number and simplify or omit the description.

In the cleaning method of the plasma processing apparatus according to the fourth embodiment, after the step S15 of introducing the carbon tetrafluoride gas, the step S41 of introducing the inert gas is added to the cleaning process according to the third embodiment. The difference.

That is, in the present embodiment, after the wafer W is carried out, the O ₂ gas is introduced (step S31) to generate the O ₂ gas plasma, and the dry cleaning process is performed by the O ₂ gas plasma (step S33). .

Then, after the oxygen gas or the like is discharged by using the exhaust device 35 (step S35), the shutter 22 is opened in the same manner as the washing process according to the third embodiment (step S13). Then, an inert gas such as carbon tetrafluoride gas or Ar gas is introduced (steps S15 and S41) to remove adhering substances adhering to the tantalum oxide film in the processing container 2 (step S17). Then, the shutter 22 is closed (step S19), and the fluorine ions or the like in the plasma processing chamber S1 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 fourth embodiment, the dry cleaning is first performed using the oxygen plasma. Therefore, the member formed by the gas shower head 40 or the like is oxidized by dry cleaning, and becomes a source of new particle generation. Then, in the present embodiment, a plasma of a carbon tetrafluoride gas and an inert gas is used together to clean the deposit of the tantalum oxide film containing the new particle generation source and the tantalum oxide film to which the non-plasma surface adheres.

At this time, in the present embodiment, after the cleaning of the oxygen plasma, the baffle 22 is opened to form the insulating region A, and the plasma is induced into the non-plasma space S3 and the exhaust space S2.

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

A plasma cleaning system for a tantalum oxide film requires a so-called low pressure condition. On the other hand, in the present embodiment, the non-plasma space S3 and the exhaust space S2 are removed by the plasma of a mixed gas of carbon tetrafluoride gas and an inert gas in an environment satisfying the low-pressure condition. Attachment of cerium oxide attached to the slurry surface.

For example, by adding Ar gas to the CF ₄ gas, plasma can be generated at a lower pressure than in the case of a single gas of CF ₄ gas.

For example, in Fig. 8, the symbol "○" indicates that the plasma is successfully induced into the non-plasma space S3 and the exhaust space S2. Further, the star mark of Fig. 8(b) indicates the program condition at the time of cleaning the oxygen plasma in step S33 of Fig. 6. The star mark of Fig. 8(a) indicates the program condition at the time of cleaning the oxygen plasma in step S33 of Fig. 7.

Fig. 8(a) shows the result of introducing a mixed gas of CF ₄ gas, Ar gas, and O ₂ gas into the plasma processing chamber S1. Fig. 8(b) shows the results when only the CF ₄ gas was introduced into the plasma processing chamber S1. In addition, in FIGS. 8(a) and 8(b), the case where the baffle 22 is closed and the oxygen plasma cleaning is performed is shown.

When a mixed gas of CF ₄ gas, Ar gas, and O ₂ gas is introduced into the plasma processing chamber S1 shown in FIG. 8( a ), only CF ₄ gas is shown as compared with FIG. 8( b ). In the case of introduction, the plasma can be induced to the non-plasma space S3 and the exhaust space S2 at a lower pressure.

Further, in Fig. 8(a), in addition to the CF ₄ gas and the Ar gas, O ₂ gas is supplied, but even if the O ₂ gas is not supplied, the Penning effect can be used as shown in Fig. 8(b). In the case of low pressure, the plasma is induced to the non-plasma space S3 and the exhaust space S2.

In the above, the cleaning method of the plasma processing apparatus has been described above. However, the cleaning method of the plasma processing apparatus according to the present invention is not limited to the above embodiment, and various types can be carried out within the scope of the present invention. Change and improvement. The matters described in the above plural embodiments can be combined in a range that does not contradict each other.

For example, in each of the above-described embodiments, an example of the adhering matter adhering to the wall surface of the plasma processing apparatus to be cleaned is described as an oxide film. However, the object to be cleaned according to the present invention is not limited thereto, and may be, for example, an attachment of a tantalum nitride film. In this case, the plasma or carbon fluoride gas of the carbon fluoride gas such as CF ₄ gas which is the same as the gas used for the removal of the deposit of the tantalum oxide film described in each of the above embodiments can be used and inactive. Plasma of gas. Further, the inert gas to be added to the carbon fluoride gas is not limited to Ar gas, and may be He gas.

Further, the object to be cleaned according to the present invention is not limited thereto, and may be an organic polymer such as C _x H _y or C _x F _y . In this case, the gas used in the removal of the organic polymer of C _x H _y or C _x F _y is preferably an oxygen-containing gas.

Specifically, when the organic polymer containing C _x H _y or C _x F _y is removed, the following first to third steps are carried out.

In the first step, the shutter 22 is opened, and a part of the area A of the plasma processing chamber S1 is insulated. The second step generates a plasma of an oxygen-containing gas introduced into the plasma processing chamber S1. In the third step, the plasma of the oxygen-containing gas is supplied from the region A in which the plasma processing chamber S1 is insulated to the non-plasma surface to remove the non-plasma surface of the non-plasma space S3 and the exhaust space S2. Attachment.

Thereby, the organic polymer of C _x H _y or C _x F _y to which the non-plasma surface of the non-plasma space S3 and the exhaust space S2 adheres can be removed. The method for supplying an organic polymer-containing plasma to a non-plasma surface to remove C _x H _y or C _x F _y may be replaced in step S15 of FIGS. 2 and 6. An oxygen-containing gas is introduced by introducing a carbon tetrafluoride gas. In steps S15 and S41 of FIGS. 4 and 7, an oxygen-containing gas and an inert gas may be introduced instead of introducing a carbon tetrafluoride gas and an inert gas.

In addition, the baffle 22 may not be fully opened as long as it is open. Since the opening of the baffle 22 is electrically insulated, a predetermined potential difference is generated from the large ground, so that the plasma cleaning effect of the embodiment can be achieved. However, when the shutter 22 is fully opened, it is preferable because the cleaning plasma is easily induced to the exhaust space S2 or the non-plasma space S3.

Further, in each of the above embodiments, the baffle 22 is moved up and down by the elevator 55. However, the cleaning process of the plasma processing apparatus according to the present invention is not limited thereto, and the baffle 22 and the deposition shielding portion 23 may be integrally moved up and down by the elevator 55.

The plasma processing apparatus related to the present invention can be applied to an ALD (Atomic Layer Deposition) device, a capacitive inductively coupled plasma (CCP), an inductively coupled plasma (ICP), a spiral trough antenna, and an electron cyclotron resonance plasma (ECR). , various types of spiral wave plasma (HWP).

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

Claims (10)

 A method for cleaning a plasma processing apparatus, which is a method for cleaning a plasma processing apparatus for plasma-treating a substrate in a plasma processing chamber in a processing vessel, comprising: a first step, a substrate after plasma treatment After moving out, insulating a portion of the plasma processing chamber; in the second step, a plasma of carbon fluoride gas is generated in the plasma processing chamber; and a third step is performed from the plasma processing chamber The insulated region is supplied to the plasma of the fluorinated carbon gas in the space outside the plasma processing chamber to remove the deposit on the non-plasma surface of the outer space.    The cleaning method of claim 1, further comprising: step 4, generating oxygen plasma in the plasma processing chamber; the first step to the third step are performed after the fourth step get on.    The cleaning method of claim 1, wherein the inert gas is introduced before the third step.    The cleaning method of claim 2, wherein the inert gas is introduced before the third step.    The cleaning method of claim 3, wherein the inert gas system is Ar gas or He gas.    A cleaning method according to any one of claims 1 to 5, which opens a baffle forming part of the plasma processing chamber to insulate a portion of the plasma processing chamber.    The cleaning method according to any one of claims 1 to 5, wherein the non-plasma surface attachment removed in the third step is a tantalum oxide or a niobium nitride.   The cleaning method according to any one of claims 1 to 5, wherein the carbon fluoride gas system is at least one of CF ₄ gas, C ₄ F ₆ gas, C ₅ F ₈ gas, and C ₆ F ₆ gas. By.  A method for cleaning a plasma processing apparatus, which is a method for cleaning a plasma processing apparatus for plasma-treating a substrate in a plasma processing chamber in a processing vessel, comprising: a first step, a substrate after plasma treatment After the removal, the portion of the plasma processing chamber is insulated; in the second step, the plasma of the oxygen-containing gas is generated in the plasma processing chamber; and the third step is performed by the plasma processing chamber. The insulating region is supplied to the plasma of the oxygen-containing gas in the space outside the plasma processing chamber to remove the deposit on the non-plasma surface of the outer space.   The cleaning method according to claim 9, wherein the non-plasma surface deposited in the third step is an organic polymer containing C _x H _y or C _x F _y .