JP6275610B2 - Plasma processing method and plasma processing apparatus - Google Patents

Description

  The present invention relates to a plasma processing method and a plasma processing apparatus.

Along with the rapid miniaturization of LSIs in recent years, high dimensional accuracy in the etching process requires high controllability and high process performance stability in order to reduce device characteristic variations. In general, changes in process performance over time in an etching process are classified into short-term process performance fluctuations and long-term process performance fluctuations. The former is caused by a change in the probability of radical adhesion to the inner wall of the chamber due to temperature fluctuations of the members in the etching chamber. The latter is attributed to the fact that reaction products generated during the etching process adhere to the inner wall of the chamber. Further, along with the miniaturization of MOSFET (Metal Oxide Semiconductor Field Effect Transistor), in recent years, a metal gate / high-K (MG / HK) structure in which a high dielectric constant (High-K) material is used for a gate oxide film has become mainstream. It has become. A Hafnium oxide film (HfO ₂ ) or the like is used as the High-K gate oxide film material, and various metal materials are used as the metal gate material. In order to ensure high process stability in the etching process by introducing the MG / HK process, a stabilization method for the metal-based reaction product is required. As described in Non-Patent Document 1, in general, metal-based reaction products are difficult to remove by conventional plasma cleaning mainly composed of fluorine for reaction products composed of Si and C. Therefore, it is necessary to study an effective method for suppressing metal-based reaction products remaining in the processing chamber. To date, the following techniques have been studied as a stabilization method against process fluctuations caused by metal-based reaction products.

  First, a technique for keeping the chamber atmosphere constant by using a seasoning technique as described in Patent Document 1 and plasma cleaning mainly using chlorine have been implemented. However, seasoning and plasma cleaning mainly composed of chlorine require a considerable number of non-product wafers (non-product wafers, dummy wafers) due to the characteristics of the process, which is often problematic in terms of cost.

  Further, as in the technique described in Patent Document 2 and Patent Document 3, a film composed of Si, O, C, or the like is formed on the inner wall of the chamber before processing the product wafer, and is removed after processing the product wafer. A method of resetting the inner wall state every time a product wafer is processed is known. Furthermore, the technique described in Patent Document 2 has a metal cleaning process mainly composed of chlorine in addition to the film forming process described above, and during the metal cleaning due to the electrode protection effect of the coating film formed on the electrode. It is described that the electrode itself can be prevented from being scraped and a non-product wafer is unnecessary.

JP 2010-177480 A JP 2011-192872 A U.S. Pat. No. 7,767,584

A. Le Gouil and 4 others: J. Vac. Sci. Technol. B24 (5) (2006) 2191

Accordingly, the inventors have examined whether or not there is a problem in the case where the above-described conventional technology is applied to microfabrication of LSI or the like in the future. As a result, it has been found that the above-described prior art does not sufficiently consider the following points.
(1) Since the coating film formed on the wall surface is consumed during the etching process, the wall surface is partially exposed during the etching process, and the amount of consumption of the etchant changes. In order to prevent process variations caused by this, the coating film needs to be formed as a film thickness that remains until the process is completed before the wafer processing. However, when wafer processing conditions with a low etching selectivity to the coating film, such as a mask (Si-based) etching process, are used, the amount of consumption of the coating film formed on the wall surface is large, which is necessary for remaining until the process is completed. Since the coating film thickness becomes enormous and the coating film forming process takes a very long time, the throughput is significantly reduced.
(2) Further, since the coating film is formed to some extent uniformly throughout the processing chamber, the coating film is much thicker than the film thickness required for electrode protection from chlorine plasma cleaning on the electrode that is not consumed during wafer processing. A coating film is formed, and it takes a lot of time to completely remove the film every wafer processing, which also causes a decrease in throughput.
(3) Furthermore, there is a concern that the coating film formed on the wall surface changes in composition and film thickness depending on the atmosphere on the inner wall of the chamber such as temperature and residue, and becomes a variation factor of plasma state in the etching process.
(4) Finally, since the composition of the coating film directly affects the plasma state during wafer processing, if the coating film forming conditions are changed, the wafer processing conditions must be changed at the same time, and mass production is started. It is extremely difficult to apply the above technology to a process that is later or close to mass production, or to change the existing coating film forming conditions, and there are limitations to the process to which the above technology can be applied. .

  An object of the present invention is to provide a high-throughput plasma processing method and plasma processing apparatus that can stabilize the plasma state during wafer processing and improve the efficiency of plasma processing without limiting the application process.

As an embodiment for achieving the above object, in a plasma processing method for plasma processing a first sample in which a film containing a metal element is disposed,
A first step of forming a coating film using plasma in a processing chamber in which the first sample is subjected to plasma processing;
After the first step, a second step of placing a second sample on a sample stage disposed in the processing chamber;
After the second step, a third step of removing the coating film using plasma,
A fourth step of carrying out the second sample from the processing chamber after the third step;
After the fourth step, a fifth step of placing the first sample on the sample stage and plasma-treating the first sample in the processing chamber;
After the fifth step, there is provided a plasma processing method comprising a sixth step of removing a deposited film deposited on the coating film in the processing chamber using plasma.

Further, in a plasma processing method of plasma processing a sample in which a film containing a metal element is arranged,
A first step of forming a coating film using plasma in a processing chamber in which the sample is plasma-treated;
After the first step, a second step of placing the sample on the sample stage and plasma processing the sample in the processing chamber;
After the second step, a third step of removing the deposited film containing the metal element in the processing chamber using plasma,
A fourth step of removing the deposited film deposited on the coating film in the processing chamber using plasma after the third step;
And a fifth step of removing the coating film in the processing chamber using plasma after repeating the second step to the fourth step by a predetermined number of samples. The processing method.

Further, a processing chamber in which the sample is plasma-processed, a plasma generation unit that generates plasma in the processing chamber, a sample stage on which the sample is placed, a current detection unit that detects a current flowing through the sample stage, In a plasma processing apparatus comprising: a voltage detection means for detecting a voltage applied to the sample stage; and a coating thickness monitor means for monitoring the thickness of a coating film covering the sample stage.
The coating film thickness monitoring unit is configured such that the sample stage is based on a difference between an impedance obtained by using the current detected by the current detection unit and the voltage detected by the voltage detection unit and an impedance obtained in advance. Obtain the magnitude relationship between the film thickness of the coating film coated thereon and the desired film thickness determined in advance,
The plasma processing apparatus further includes a control device that performs plasma processing of the sample when the coating film is coated on the sample stage.

  According to the present invention, it is possible to provide a high-throughput plasma processing method and plasma processing apparatus that can stabilize the plasma state during wafer processing and improve the efficiency of plasma processing without limiting the application process.

It is a longitudinal cross-sectional view for demonstrating the structure of the plasma processing apparatus which concerns on the 1st Example of this invention. It is an etching process sequence diagram in the plasma processing method concerning the 1st example of the present invention. It is the sequence diagram which simplified the etching process sequence shown to FIG. 2A. An example of chlorine-based plasma cleaning conditions in the plasma processing method according to the first embodiment of the present invention will be described. An example of fluorine plasma cleaning conditions in the plasma processing method according to the first embodiment of the present invention will be described. It is a longitudinal cross-sectional view which shows the structure of the plasma processing apparatus which concerns on the 2nd Example of this invention. It is a graph which shows the relationship between the scraping amount of the electrode surface by chlorine system plasma cleaning, and the coating film thickness which can protect an electrode. It is an etching process sequence diagram in the plasma processing method which concerns on the 2nd Example of this invention.

The inventors examined the above-mentioned problems and adopted the following steps. That is, in the plasma processing method, first, a coating film is formed before the lot processing of the processing material. The purpose of this coating film formation is to protect the electrode surface from electrode damage caused by chlorine-based plasma. Next, after the dummy wafer is placed on the electrode, the coating film formed on the portion other than the electrode surface is removed, and after the dummy wafer is carried out, product wafer processing is performed. Finally, in order to remove reaction products generated in the product wafer processing, chlorine-based plasma cleaning for metal-based reaction products and fluorine-based plasma cleaning for non-metal-based reaction products are performed. From product wafer processing to chlorine-based plasma cleaning and fluorine-based plasma cleaning are repeated for the number of product wafers that are continuously processed at once, and after all product wafer processing is completed, the coating film on the remaining electrode is removed. Remove. According to the above procedure, it is possible to create a state in which the coating film does not affect the plasma during product wafer processing and the electrode is protected by the coating film during chlorine plasma cleaning.
Hereinafter, the present invention will be described using examples. In the drawings, the same reference numerals indicate the same components.

  A plasma processing method and apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view for explaining the configuration of a microwave ECR (Electron Cyclotron Resonance) plasma etching apparatus which is an example of a plasma processing apparatus according to the present embodiment. An electric field, a magnetic field supply device, and a power supply installed outside the container are schematically shown. Equipment and devices other than these are arranged according to required performance or specifications so as not to significantly impair the operation and effect of the invention according to this embodiment by those who have ordinary knowledge in the technical field according to this embodiment. Or it can be deleted.

  In the plasma processing apparatus shown in FIG. 1, a disc-shaped shower plate 102 having a plurality of through holes for introducing a reactive gas and a dielectric window above a processing chamber 101 having a cylindrical shape with an open top. 103 (made of quartz or the like) is installed, and the processing chamber 101 is hermetically sealed by the dielectric window 103. The flow rate of the reactive gas is controlled by the gas supply device 104 and is supplied to the processing chamber 101 via the shower plate 102. A solenoid coil 105 that forms a magnetic field inside the processing chamber 101 is disposed on the outer periphery and above the processing chamber 101, and the magnetic field in the processing chamber 101 can be controlled by the current of the solenoid coil 105. In addition, a magnetron 106 that generates electromagnetic waves and a waveguide 107 (or antenna) that transmits electromagnetic waves are installed in an open part above the processing chamber 101, and a cylindrical space (cavity resonance) above the dielectric window 103. Part). The electromagnetic wave used in the present embodiment is a 2.45 GHz microwave by the magnetron 106, but this is not particularly limited by the effect and action. The microwave oscillated by the magnetron 106 propagates through the waveguide 107, passes through the dielectric window 103, and is introduced into the processing chamber 101. A vacuum exhaust pump (not shown) is connected to the lower portion of the processing chamber 101 through a vacuum exhaust pipe 108 so that the processing chamber 101 can be evacuated. In addition, a substrate electrode (sample stage) 109 installed at the lower portion of the processing chamber 101 so as to face the shower plate 102 at the upper portion of the processing chamber 101 is covered with a dielectric film (not shown). The wafer (sample) 110 is transferred into the processing chamber 101 by a transfer device such as a robot arm (not shown). Then, it is placed on the substrate electrode 109 and is electrostatically attracted by a DC voltage applied from the DC power source 111 to an electrode (not shown) inside the substrate electrode 109. The high frequency power source 112 can apply a high frequency to the substrate electrode 109 via the high frequency matching unit 113. An earth 114 connected to the ground is installed in the middle of the processing chamber 101, and the high-frequency current applied to the substrate electrode 109 by the high-frequency power source 112 flows to the earth 114 through plasma. A cylindrical inner cylinder 115 (made of quartz) is installed above the ground 114 and insulated.

  The etching process in the plasma processing apparatus starts with the following flow. A process gas is introduced into the processing chamber 101 from the gas supply device 104, and a desired pressure is controlled. The processing gas is excited by an electromagnetic wave oscillated from the magnetron 106 and supplied into the processing chamber 101 and electron cyclotron resonance by a magnetic field formed in the processing chamber 101, and plasma is generated in the processing chamber 101. High frequency power is applied from a high frequency power source 112 connected to the substrate electrode 109, ions are drawn from the plasma onto the upper surface of the wafer 110 placed on the substrate electrode 109, and an etching process is performed.

  FIG. 2A is a diagram illustrating an etching sequence in the plasma processing method according to the present embodiment. The plasma processing method according to the present embodiment includes the following six elements, and an etching process is performed according to the procedure shown in FIG. 2A. (1) Formation of coating film on wall surface, (2) Removal of coating film other than on substrate electrode 109, (3) Product wafer processing, (4) Plasma cleaning mainly composed of chlorine, (5) Fluorine Mainly plasma cleaning, (6) removal of the remaining coating film on the substrate electrode 109.

  Any number of product wafers are continuously processed at a time, and after each product wafer process, plasma cleaning mainly composed of chlorine and plasma cleaning mainly composed of fluorine are always processed.

Details of each element will be described below in accordance with the processing sequence shown in FIG. 2A. First, a coating film is formed by plasma A on the inner wall of the processing chamber 101 (step S201). The coating film is formed on the surface of the substrate electrode 109 and on the entire wall surface regardless of the upper and lower portions in the processing chamber 101. This coating film is a coating film containing Si, a film containing carbon as a main component, a film containing Si as a main component, a film containing Si and oxygen (O), or Si and carbon (C). Or a film containing Si and nitrogen (N). The process gas for forming these coating films includes, for example, a film containing Si and oxygen (O), a mixed gas of SiCl ₄ and O ₂ , and a film containing Si and carbon (C). Is a mixed gas of SiCl ₄ and CH _{4, and} a mixed gas of SiCl ₄ and N ₂ is used for a film containing Si and nitrogen (N), and these are diluted with a rare gas such as Ar. Also good. A coating film is formed by generating plasma using these process gases. In this embodiment, a case where a film mainly composed of SiO ₂ is formed by a mixed gas of SiCl ₄ and O ₂ will be described.

  Next, the dummy wafer is transferred into the processing chamber 101 and placed on the substrate electrode 109 (step S202). Thereafter, the coating film formed on the wall surface in the processing chamber 101 is removed by plasma cleaning mainly using fluorine by the plasma B (step S203). At this time, since the dummy wafer is placed on the substrate electrode 109, the coating film on the surface of the substrate electrode 109 is protected by the dummy wafer, and is not exposed to plasma and is not etched. After all the coating films on the inner walls of the processing chamber 101 other than the upper surface of the substrate electrode 109 are removed, the dummy wafer is carried out (step S204). From the above, a state in which the coating film is formed only on the upper surface of the substrate electrode 109 can be formed in the processing chamber 101. As the process gas of plasma B, for example, a mixed gas of NF3, SF6, or a diluent gas such as Ar is used. Up to this point, (1) coating film formation on the wall surface (S201) and (2) removal of coating films other than on the substrate electrode 109 (S202-S204) are completed.

  When the coating film is formed only on the substrate electrode 109, a product wafer on which a silicon film, a carbon film, a metal film, or the like is stacked is placed on the substrate electrode 109 (step S205). Next, plasma is generated and plasma processing such as etching is performed (step S206). Thereafter, the product wafer is unloaded from the substrate electrode 109 (step S207). A plasma is any plasma constructed by a single or multiple steps. Thereby, the (3) product wafer processing is completed.

When the product wafer processing is completed, plasma cleaning mainly including chlorine is performed by forming plasma C (step S208), and metal among the reaction products deposited on the inner wall of the processing chamber 101 generated during the product wafer processing. The reaction product containing is removed. In this cleaning, a mixed gas of Cl ₂ gas and SiCl ₄ gas or a mixed gas of Cl ₂ gas and BCl ₃ gas can be used. Subsequently, a reaction composed of silicon or carbon containing no metal among the reaction products deposited on the inner wall of the processing chamber 101 by the plasma cleaning process (step S209) mainly composed of fluorine by forming the plasma D. The product is removed. As a result, (4) plasma cleaning mainly composed of chlorine and (5) plasma cleaning mainly composed of fluorine are completed.

  The chlorine-based plasma cleaning process and the fluorine-based plasma cleaning process are repeatedly performed for each product wafer by the number of product wafers processed continuously.

  The coating film remaining on the substrate electrode 109 after the last product wafer processing, which is continuously processed at one time, is completely removed by plasma cleaning mainly composed of fluorine by the plasma B (step S210).

  The process is performed by the above etching process sequence. The coating film formed on the substrate electrode 109 is consumed (reduced in film thickness) by plasma cleaning mainly using chlorine by plasma C and plasma cleaning mainly by fluorine by plasma D. Here, N is the number of processed product wafers that are continuously processed at one time, Z is the coating film thickness formed on the substrate electrode 109, and the coating film thickness is consumed by plasma cleaning mainly composed of chlorine by plasma C. When the coating film thickness consumed by the plasma cleaning mainly composed of fluorine by X and plasma D is Y, the coating film Z is formed to satisfy the following formula (1).

Z> N (X + Y) (1)
If the coating film Z becomes too thick, it may affect the surface temperature of the product wafer due to a decrease in the wafer adsorption force to the substrate electrode 109 and the heat conduction to the wafer. The number of processed product wafers N that are continuously processed at one time is preferably about one lot (25).

FIG. 3 shows plasma cleaning conditions mainly composed of chlorine in the plasma C. This chlorine-based plasma cleaning efficiently removes reaction products containing metal deposited on the inner wall of the processing chamber 101 and has a high etching selectivity to the coating film. In this plasma cleaning mainly composed of chlorine, an additive gas is mixed with Cl ₂ gas, and either SiCl ₄ gas or BCl ₃ gas is used as the additive gas. The flow rate ratio of the additive gas to the Cl ₂ gas can be used in the range of 0.2 to 0.5, and preferably in the range of 0.3 to 0.4. The pressure in the processing chamber 101 is preferably in the range of 0.3 Pa to 3.0 Pa. Further, they may be diluted with a rare gas such as Ar in addition to the additive gas.

  FIG. 4 shows plasma cleaning conditions mainly for fluorine in the plasma D. This fluorine-based plasma cleaning efficiently removes reaction products composed of silicon, carbon, etc. that do not contain metal deposited on the inner wall of the processing chamber 101, and has a high etching selectivity to the coating film. Have The pressure in the processing chamber 101 can be used in the range of 0.05 Pa to 10 Pa, 0.1 Pa to 10 Pa is a practical range, and 0.1 Pa to 3.0 Pa is a suitable range.

FIG. 2B is a simplified sequence diagram of the etching process sequence shown in FIG. 2A. The other plasma processing method according to the present embodiment shown in FIG. 2B is composed of the following five elements. Compared with the procedure shown in FIG. 2A, “removing the coating film other than on the substrate electrode 109” is performed for the purpose of improving the throughput. The process is simplified by omitting elements. That is, (1) coating film formation on the wall surface, (2) product wafer processing, (3) plasma cleaning mainly composed of chlorine, (4) plasma cleaning mainly composed of fluorine, (5) on the substrate electrode 109 Removing the remaining coating film. Steps S201 and S205 to S210 in FIG. 2A correspond to steps S211 and S212 to S217 in FIG. 2B. Similar to the processing procedure of FIG. 2A, an arbitrary number of product wafers are continuously processed at one time, and after each product wafer processing, plasma cleaning mainly composed of chlorine and plasma cleaning mainly composed of fluorine are always processed.

  Using the plasma processing apparatus shown in FIG. 1 and the cleaning conditions shown in FIGS. 3 and 4, according to the etching process sequence shown in FIG. The etching selectivity to the coating film is high, the coating film thickness can be reduced, the time required to remove the coating film can be reduced, the plasma state during wafer processing can be stabilized, and the plasma processing efficiency can be improved. .

  1 and the cleaning conditions shown in FIGS. 3 and 4 were used to repeat the processing of 25 wafers per lot a plurality of times in accordance with the etching process sequence shown in FIG. 2B. In addition, the throughput could be further improved by omitting the steps.

  As described above, according to this embodiment, it is possible to provide a high-throughput plasma processing method and plasma processing apparatus that stabilize the plasma state during wafer processing and improve the efficiency of plasma processing without limiting the application process. .

  A plasma processing method and apparatus according to a second embodiment of the present invention will be described with reference to FIGS. Note that the matters described in the first embodiment and not described in the present embodiment can be applied to the present embodiment as long as there are no special circumstances. FIG. 5 is a longitudinal sectional view showing the structure of the plasma processing apparatus according to the second embodiment of the present invention. In this example, in addition to the configuration of the plasma processing apparatus shown in Example 1, the following configuration is provided or implemented, so that the coating film on the substrate electrode (sample stage) 109 is always monitored, and chlorine is mainly used. Thus, it is possible to maintain and manage the coating film thickness so that the substrate electrode 109 is not damaged by the plasma cleaning. FIG. 6 is a grab showing the relationship between the amount of scraping of the surface of the substrate electrode 109 by plasma cleaning mainly composed of chlorine and the protective coating thickness of the surface of the substrate electrode 109. As can be seen from FIG. 6, when the coating film on the electrode is 10 nm or more, the etching effect on the electrode surface during the chlorine plasma cleaning process can be made small enough to be ignored by the protective effect of the coating film. Therefore, if the coating film on the electrode is maintained at 10 nm or more, plasma cleaning mainly composed of chlorine can be performed without protecting the substrate electrode 109 with a non-product wafer (dummy wafer).

  Hereinafter, differences from the first embodiment will be mainly described. A voltage / current probe (hereinafter referred to as V / I probe) 201 capable of measuring a high-frequency current value or a voltage value is connected between the high-frequency power source 112 and the substrate electrode 109, and an arithmetic unit capable of calculating impedance from the measured value 202, a reference data storage unit 203 for storing an impedance value when the coating film on the substrate electrode 109 is 10 nm, and a process sequence control unit 204 for controlling the processing procedure are connected.

In general, when high-frequency power is applied to the substrate electrode 109, the high-frequency current flows to the ground 114 through the plasma formed in the substrate electrode 109 and the processing chamber 101. A sheath is formed on the surface of the plasma and ground 114 and the substrate electrode 109. When a coating film is formed on the inner wall of the processing chamber 101 as in step S <b> 201 shown in FIG. 2A, the coating film is formed on the substrate electrode 109. For example, in this embodiment, the main component of the coating film formed by the mixed gas of SiCl ₄ and O ₂ is SiO ₂ and an insulating film is formed. Here, the high-frequency impedance Z of the insulating film is described by the following equation (2). C is the capacitance, ω is the angular frequency, ε is the dielectric constant of the insulating film, d is the coating film thickness, and S is the coating film area.

Z = 1 / jωC = d / jεS (2)
Assuming that the plasma density to be formed is constant for different coating thicknesses, if the relative dielectric constant ε and the area S of the coating film are known, the substrate electrode 109 is connected to the plasma and the ground 114. By measuring the synthetic high-frequency impedance, it is possible to measure the thickness change of the coating film as the impedance change.

  FIG. 7 is an etching process sequence diagram in the plasma processing method according to the present embodiment in which a coating film thickness monitor on the substrate electrode 109 using impedance is applied. Hereinafter, differences from the etching processing sequence shown mainly in the first embodiment will be described. Note that steps S201 to S204 in FIG. 2A correspond to steps S701 to S704 in FIG. Steps S205 to S207 correspond to step S705. Steps S208 to S209 correspond to steps S706 to S707. In FIG. 7, the coating film other than on the substrate electrode 109 is removed (step S703), product wafer processing is performed (step S705), and plasma cleaning mainly using fluorine by the plasma D is processed (step S707). Immediately after being formed, plasma with a rare gas such as Ar is formed, and at the same time, a high frequency bias is applied in the range of 1 W to 50 W (step S708). During this plasma discharge, the high-frequency current value or voltage value by the V / I probe 201 is measured (step S709), and the impedance value is calculated from the measured value by the calculation unit 202 and stored in the reference data storage unit 203. It is compared with the impedance value when the coating film on the substrate electrode 109 is 10 nm (step S710), and whether or not the coating film thickness on the substrate electrode 109 is 10 nm or more is determined from the positive or negative difference (step S710). S711). From the impedance value comparison result, if the coating film thickness on the substrate electrode 109 is 10 nm or more, the next product wafer processing is performed (step S705). If the coating film thickness is less than 10 nm, the coating film remaining on the substrate electrode 109 is The plasma B is removed by plasma cleaning mainly composed of fluorine (step S712), and the process sequence is started again by returning to the formation of the coating film thickness in the processing chamber 101 (step S701). All the above configurations are connected to the process sequence control unit 204, and the timing and operation amount thereof are controlled so as to operate in an appropriate sequence. In the plasma processing apparatus according to the present embodiment, these procedures are performed automatically and can be automatically sequenced. According to this method, the coating film thickness on the substrate electrode 109 is always maintained at 10 nm or more, and the plasma cleaning mainly composed of chlorine which does not require the non-product wafer mounting and does not cause the substrate electrode 109 to be damaged can be performed.

  Using the plasma processing apparatus shown in FIG. 5 and the cleaning conditions shown in FIGS. 3 and 4, according to the etching process sequence shown in FIG. The etching selectivity to the coating film is high, the coating film thickness can be reduced, the time required to remove the coating film can be reduced, the plasma state during wafer processing can be stabilized, and the plasma processing efficiency can be improved. . Moreover, a dummy wafer can be made unnecessary by obtaining the thickness of the coating film formed on the substrate electrode.

  As described above, according to this embodiment, it is possible to provide a high-throughput plasma processing method and plasma processing apparatus that stabilize the plasma state during wafer processing and improve the efficiency of plasma processing without limiting the application process. .

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, in the above-described embodiment, the embodiment of the ECR plasma apparatus has been particularly described. However, the present invention can be applied to other plasma generation apparatuses or methods such as inductively coupled plasma (ICP) and capacitively coupled plasma (CCP). Even if used, the same effect is obtained. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 101 ... Processing chamber, 102 ... Shower plate, 103 ... Dielectric window, 104 ... Gas supply apparatus, 105 ... Solenoid coil, 106 ... Magnetron, 107 ... Waveguide, 108 ... Vacuum exhaust pipe, 109 ... Substrate electrode (sample stand) 110 ... Wafer (sample), 111 ... DC power supply, 112 ... High frequency power supply, 113 ... High frequency matcher, 114 ... Ground, 115 ... Inner cylinder, 201 ... V / I probe, 202 ... Calculation unit, 203 ... Reference data Storage unit, 204... Process sequence control unit.

Claims (9)

In a plasma processing method of performing plasma processing on a first sample in which a film containing a metal element is disposed in a processing chamber,
A first step of forming a coating film in the processing chamber using plasma;
After the first step, a second step of placing a second sample on a sample stage disposed in the processing chamber;
After the second step, a third step of removing the coating film using plasma,
A fourth step of carrying out the second sample from the processing chamber after the third step;
After the fourth step, a fifth step of placing the first sample on the sample stage and plasma-treating the first sample;
And a sixth step of removing the deposited film deposited by the plasma treatment of the first sample after the fifth step. The plasma processing method according to claim 1,
The plasma processing method is characterized in that the sixth step is a plasma processing for selectively removing the deposited film with respect to the coating film. The plasma processing method according to claim 1,
When the film thickness of the coating film after the third step is Z, the number of the first samples is N, and the film thickness of the coating film removed in the sixth step is X, the Z Wherein the peritoneum is formed by the first step so as to satisfy Z> N × X. In the plasma processing method of Claim 1 or Claim 2,
When the number of the first samples is N, the fifth step and the sixth step are repeated N times, and then a seventh film for removing the coating film on the sample table using plasma is used. The plasma processing method further comprising a step. In the plasma processing method according to any one of claims 1 to 4,
The sixth step includes a first cleaning step of removing a deposited film deposited in the processing chamber using plasma and containing a metal element;
After the first cleaning step, the plasma processing method includes a second cleaning step of removing a deposited film that is deposited in the processing chamber using plasma and contains other than a metal element. In the plasma processing method of Claim 5,
The plasma in the first cleaning step is generated using a mixed gas of Cl ₂ gas and SiCl ₄ gas or a mixed gas of Cl ₂ gas and BCl ₃ gas. In the plasma processing method according to any one of claims 1 to 6,
The plasma processing method, wherein the coating film is a film containing silicon. A processing chamber in which a sample is plasma-processed, a plasma generation means for generating plasma in the processing chamber, a sample stage on which the sample is placed, a current detection means for detecting a current flowing through the sample stage, and the sample In a plasma processing apparatus comprising a voltage detection means for detecting a voltage applied to a table, and a film thickness monitor means for monitoring the film thickness of a coating film coated on the sample table,
The film thickness monitoring means is based on a difference between an impedance obtained using the current detected by the current detection means and a voltage detected by the voltage detection means, and an impedance obtained in advance. And the desired film thickness,
A plasma processing apparatus, further comprising: a control device that performs plasma processing of the sample based on the obtained magnitude relationship when the coating film covers the sample stage. The plasma processing apparatus according to claim 8 , wherein
When the film thickness is less than 10 nm, the control device
The plasma is characterized in that after the coating film is coated on the sample table until the thickness of the coating film to be coated on the sample table reaches the desired film thickness, the plasma treatment of the next sample is performed. Processing equipment.

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