JPH04271122A - Plasma processing equipment - Google Patents

Abstract

PURPOSE:To apply an ECR type plasma processing equipment equipped with a plasma forming chamber which is equipped with a microwave transmitting window and a plasma leading-out window on both end surfaces, respectively, and coaxially surrounded by a main coil, and a reaction chamber linked with the plasma forming chamber via the plasma leading-out window in which reaction chamber a substrate stand is arranged, to an equipment capable of forming a film which is free from contamination and has uniform thickness and quality on the whole surface of a large diameter substrate and of high speed dry cleaning of the substrate stand. CONSTITUTION:An electrostatic chuck 11 is used for a substrate stand. The structure of said chuck is so constituted that the peripheral part of the surface of an insulating layer on which a substrate 9 is attracted and retained is covered with a metal surface to form a ring type metal surface 12 on the peripheral side of the substrate, and electric field of the substrate periphery is made uniform when an RF bias is applied. The ring type metal surface 12 is formed low, in order to be able to have an inner diameter which does not expose the insulating layer surface. Hence the dry cleaning in the vicinity of the electrostatic chuck 11 can be realized at a high speed by applying the RF bias.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to semiconductor integrated circuits,
In particular, it is a manufacturing device for DRAM by microfabrication of LSI, etc., which has a microwave transmission window and a plasma extraction window on both end faces, and is coaxially surrounded by a main coil and has an electron cyclotron resonance magnetic field region formed inside. a symmetrical plasma generation chamber; a reaction chamber that communicates with the plasma generation chamber through the plasma extraction window and includes a substrate pedestal therein that holds a substrate to be processed; and an RF power source that applies an RF bias to the substrate pedestal. The present invention relates to an ECR (electron cyclotron resonance) type plasma processing apparatus comprising:

0002

2. Description of the Related Art Conventionally, as this type of plasma processing apparatus, one shown in FIG. 3, for example, is known. This device is
A plasma generation chamber 3 formed as a microwave cylindrical cavity resonator, a main coil 5 coaxially surrounding the plasma generation chamber 3, and a substrate stand 10 holding a substrate to be processed (hereinafter referred to as a substrate) 9 are arranged. The main components are a reaction chamber 7 and an RF power source 20 that applies an RF bias to the substrate 9.

The plasma generation chamber 3 is provided with a microwave transmission window 2 and a plasma extraction window 8 on both end faces, and a substrate 9
For example, when forming a SiO film as an insulating film on the surface of
The electron cyclotron magnetic field plane (hereinafter referred to as the ECR domain plane) with the GHz microwave is the plasma generation chamber 3.
N2 O gas formed within the plasma generating chamber 3 and introduced into the plasma generating chamber 3 from the plasma generating gas introduction system 4 is efficiently converted into plasma near the ECR region surface. This plasma is transmitted from the plasma extraction window 8 to the substrate table 10 along a diverging magnetic field formed by the main coil 5 in which lines of magnetic force spread in the direction of the substrate table 10.
While moving in the direction, the reaction gas SiH4 introduced from the reaction gas introduction system 6 into the reaction chamber 7 is decomposed and activated. On the other hand, below the reaction chamber 7, a subcoil 15 is arranged coaxially with the main coil 5, and forms a magnetic field in the opposite direction to the magnetic field formed by the main coil 5, so that the axial magnetic field component in the reaction chamber 7 is zero. A cusp magnetic field having a so-called cusp surface is formed, and in response to the high magnetic flux density at the center of the diverging magnetic field, the moving plasma becomes dense at the center and rapidly spreads in the radial direction near the cusp surface. It arrives at a more uniform density on the substrate along with the activated reactant gas.

Further, an RF bias is applied to the substrate 9 from an RF power source 20 via the substrate table 10, and due to the difference in mobility between electrons and ions in the plasma in front of the substrate, a negative bias potential on the substrate surface is increased. Since the electric field due to this bias potential is directed toward the peripheral wall of the reaction chamber 7, the electric field strength on the substrate surface increases as it goes toward the peripheral edge, and more ions in the plasma are attracted toward the substrate peripheral edge, making the plasma more uniform. The O+ implanted at a uniform density activates the reaction on the substrate surface, and the ion bombardment effect due to the negative bias potential is also added, forming a SiO film with a uniform thickness and dense film quality. be done. and,
The plasma involved in this film formation is created by using low-pressure gas to cause the electron cyclotron motion of the electrons involved in plasma formation to occur in a state of resonance with the microwave frequency, so that the microwave power is efficiently absorbed by the electrons. , plasma density,
Plasma activity is high and substrate temperature is room temperature to 200℃.
It becomes possible to form films even at low temperatures of ℃, making it possible to perform microfabrication with submicron rules.

[0005]

[Problems to be Solved by the Invention] By the way, the substrate stand 10 that holds the substrate 9 is generally of a mechanical chuck type using mechanical means, but the arms of the chuck cover a part of the substrate, and this part cannot form a semiconductor device and results in the loss of valuable surface area of the substrate. Also,
Since the force of the chuck is applied only to a small portion of the substrate surface, it does not have the function of correcting the warp and flattening the board if it is warped. For this reason, the use of electrostatic chucks that utilize electrostatic attraction to attract and hold a substrate in close contact with the surface of a flat insulating layer is increasing. This electrostatic chuck has a plurality of electrodes such as two semicircular plate electrodes arranged in one plane so as to form a suction electrode whose outer diameter is larger than the diameter of the substrate to be processed. It is embedded in an insulator so that a common flat insulating layer is formed on both sides, and examples of its structure include, for example, Japanese Patent Publication No. 63-11426.
It is shown in the publication No. In this structure example, the electrostatic chuck consists of two aluminum semicircular plate electrodes arranged in one plane with their diametric sides facing each other, and a circular suction electrode embedded in an insulating material such as polyethylene. It is considered as something. In the case of an electrostatic chuck with such a structure, as shown in FIG. 4, the application of RF bias to the substrate is performed by connecting the non-grounded side terminal of the RF power source through the capacitor 21 that constitutes a high-pass filter. This is done by connecting to a suction electrode. Here, the reference numeral 23 is a DC power supply, which supplies a suction voltage to the electrostatic chuck 11. Further, reference numeral 22 indicates a low-pass filter consisting of a solenoid. However, such conventional electrostatic chucks have the following problems.

(1) When this type of electrostatic chuck is used as a substrate stand, a film is deposited even on the portion of the surface of the insulating layer that is not covered by the substrate. When the deposition thickness reaches approximately 100 μm, the film begins to peel off due to internal stress in the film.
There was a problem that particle contamination occurred on the substrate. Since the substrate surface has a fine structure on the submicron order,
If particles of similar size adhere, the yield of semiconductor devices will drop significantly.

In order to solve this problem, before the film deposited in the apparatus reaches a thickness of about 100 μm, a fluorine-based etching gas is introduced into the plasma generation chamber to turn it into plasma, and this plasma is applied to the film. A dry cleaning method is used to remove the particles by removing them. however,
When RF bias is applied to efficiently remove the film around the electrostatic chuck, the electrostatic chuck body is also etched at the same time, and if the insulator of the electrostatic chuck is ceramic, carbon and sodium, which are the constituent components of the electrostatic chuck, are etched. There is a problem that the inside of the reaction chamber becomes contaminated due to heavy metals and other heavy metals, and high-speed cleaning is not possible.
For this reason, there was a problem in that the cleaning time of the device was increased, and the operating rate of the device was lowered. The reason why ceramics are used as the insulator of an electrostatic chuck is that when the insulator is made of polyethylene, for example, the softening temperature of polyethylene is 12
On the other hand, ECR is characterized by low-temperature film formation.
Even with type plasma processing equipment, the substrate temperature during film formation is 150℃.
Since the electrostatic chuck can reach ~200°C, it is necessary to keep the electrostatic chuck at a low temperature, but organic synthetic resins such as polyethylene have low thermal conductivity and require a lot of consideration to keep the electrostatic chuck at a low temperature. be.

(2) In recent years, in order to improve the throughput of semiconductor manufacturing equipment, the diameter of substrates has become larger, and electrostatic chuck bodies have also become larger accordingly. However, when the diameter of the substrate becomes on the order of 200 mm, it is necessary to use a suction electrode with a diameter sufficiently larger than on the order of 200 mm in order to equalize the electric field around the edge of the substrate. Because the size of the chuck is limited when using an electrostatic chuck with existing plasma processing equipment, the suction electrode is embedded to the full outer diameter of the electrostatic chuck, making it possible to create a reliable electrostatic chuck. The problem was that it was very difficult to obtain.

An object of the present invention is to be able to clean the area around the substrate table at high speed without contaminating the inside of the device by applying an RF bias when dry cleaning the inside of the device, and to be able to handle large diameter substrates. Film thickness on the entire surface of the substrate,
An object of the present invention is to provide an ECR type plasma processing apparatus capable of forming a film with uniform film quality.

0010

[Means for Solving the Problems] In order to solve the above problems, in the present invention, both end faces are provided with a microwave transmission window and a plasma extraction window, respectively, and the main coil coaxially surrounds the main coil and has electron cyclotron resonance inside. an axially symmetrical plasma generation chamber in which a magnetic field region is formed; a reaction chamber that communicates with the plasma generation chamber through the plasma extraction window and has a substrate stand therein that holds a substrate to be processed; An ECR type plasma processing apparatus equipped with an RF power supply for applying a bias is mounted on the substrate table with two plates arranged in one plane so as to form a suction electrode whose outer diameter is larger than the diameter of the substrate to be processed. A plurality of electrodes such as semicircular plate electrodes are embedded in an insulator so that a common flat insulating layer is formed on the same side of the plurality of plate electrodes, and the surface of the insulating layer is attached to the substrate to be processed by electrostatic attraction. An electrostatic chuck is used that attracts and holds the insulating layer in close contact with the insulating layer, and the outer diameter of the insulating layer has a ring-shaped opposing surface that faces the attracting electrode with a significant width between the peripheral edge of the surface of the insulating layer and the attracting electrode. The device shall be covered by a ring-shaped metal surface larger than the

In this case, the ring-shaped metal surface covering the peripheral edge of the insulating layer surface of the electrostatic chuck is designed such that its height is lower than the insulating layer surface inside the metal surface, and its inner diameter is smaller than the substrate to be processed. It is preferable if the diameter is smaller than the diameter of the diameter.

[0012] As described above, plasma processing using an electrostatic chuck as a substrate stage in which the surface of the insulating layer on the inside of the ring-shaped metal surface, on which the substrate to be processed is suctioned and held in close contact, is formed higher than the ring-shaped metal surface. Dry cleaning, which uses etching gas to remove the film that adheres to the inside of the processing equipment, covers the surface of the insulating layer of the electrostatic chuck with a protective plate made by vapor-depositing aluminum on both sides of the same substrate as the processing target. It is preferable to use a device that performs this process.

[0013] The metal surface covering the peripheral edge of the insulating layer surface of the electrostatic chuck in a ring shape is preferably formed as a metal sputtered film.

[0014]

[Operation] In this way, the peripheral edge side of the surface of the insulating layer is covered with a ring-shaped metal surface having a larger outer diameter than the attracting electrode and having a ring-shaped opposing surface facing the attracting electrode with a significant width through the insulating layer. When an RF power source is connected to the attraction electrode of the electrostatic chuck by using an electrostatic chuck as a substrate stand, the ring-shaped metal surface is capacitively coupled to the attraction electrode using the insulating layer as a dielectric. A negative bias potential approximately equal to that of the substrate is also generated on the metal surface. Since the ring-shaped metal surface shields the peripheral edge of the attraction electrode from the substrate, the electric field on the peripheral edge of the substrate is made uniform, and
An electric field distribution is formed on the metal surface where the electric field strength becomes stronger in the radial direction, and the plasma on the front side of the substrate, which is almost uniform, is made uniform by the divergent magnetic field and the cusp magnetic field, and the film thickness is increased from the center of the substrate to the periphery. A film with uniform quality can be formed. According to experiments, the conventional film thickness distribution of 4 to 5% was suppressed to 2 to 3%.

[0015] Then, the ring-shaped metal surface covering the peripheral edge of the insulating layer surface of the electrostatic chuck is arranged so that the height is lower than the inner insulating layer surface of the metal surface and the inner diameter is the same as that of the substrate to be processed. If it is formed to be smaller than the diameter, a film will not be deposited on the peripheral edge of the insulating layer surface, and therefore, during cleaning,
The inside of the device will not be contaminated by carbon, sodium, and other heavy metals contained in the insulating layer. For example, when cleaning or removing a SiO film deposited inside the device, an RF bias is applied to the electrostatic chuck to supply a large amount of F+ in the fluorine-based cleaning gas to the SiO film deposited on the ring-shaped metal surface. 3 compared to the case where the peripheral edge of the insulating layer surface is exposed.
The SiO film can be removed at an etching rate of ~10 times.

Furthermore, when dry cleaning the inside of the apparatus, if the surface of the insulating layer of the electrostatic chuck is covered with a protection plate made by vapor-depositing aluminum on both sides of the same substrate as the substrate to be processed, a metal plate can be used as the protection plate. The protection plate is lighter compared to the case where the protection plate is used, and the protection plate is reliably adsorbed, especially when the device processes the substrate with the surface to be processed facing downward in the vertical direction, which prevents the insulating layer from being accidentally etched. There is no risk of being attacked by gas. Therefore, there is no risk of contamination within the device due to carbon, sodium, and other heavy metals in the insulating layer, and the yield of manufactured semiconductor devices is improved by avoiding contamination of the substrate with these substances during the next film formation. Can be done.

Furthermore, if the ring-shaped metal surface is formed using a metal sputtered film, the metal surface can be formed with high dimensional accuracy and with ease in terms of manufacturing technology.

[0018]

Embodiment FIGS. 1 and 2 show an embodiment of a plasma processing apparatus according to the present invention. In these figures, the same members as in FIGS. 3 and 4 are given the same reference numerals. The surface of the insulating layer on the side of the disc-shaped ceramic substrate 9 in which the suction electrode 11A, which is composed of two semicircular flat plate electrodes arranged in one plane with their diameter sides facing each other, is formed into a ring whose peripheral side is lower in height than the central part. Aluminum is formed on this surface, the side surface of the step between this surface and the central surface, and the peripheral wall surface of the disc-shaped ceramic.
A sputtered film 12 is formed. The ring-shaped surface on the peripheral edge side of the surface of the insulating layer has an inner diameter 10 to 10 mm larger than the diameter of the substrate 9.
Formed 20mm smaller and adsorbed to the surface of the insulating layer in the center.
Even if the held substrate 9 is misaligned due to transportation error during suction, the surface of the insulating layer is reliably covered, and capacitive coupling is prevented between the ring-shaped surface of the Al sputtered film and the suction electrode 11A. A ring-shaped opposing surface with a sufficient width is formed. In addition, the level difference between the surface of the insulating layer at the center and the ring-shaped surface at the periphery is set to 30 μm, and the thickness of the Al sputtered film is set to 20 μm to ensure that the substrate 9 is held in close contact with the surface of the insulating layer at the center by suction. In addition, by reducing the gap between the lower surface of the substrate 9 and the Al sputtered film and using the sputtered film at the stepped portion, the substrate 9
and the Al sputtered film are substantially in contact with each other, so that the negative bias potential appearing on the Al sputtered film when an RF bias is applied is substantially the same as that on the substrate 9.

Furthermore, as mentioned above, by forming the ring-shaped metal surface on the peripheral edge side of the insulating layer surface of the electrostatic chuck with an Al sputtered film, compared to the case where the ring-shaped metal surface is formed of a metal plate, etc. , it is possible to accurately ensure a gap between the lower surface of the substrate and the upper surface of the metal plate, and it is also easy to form in terms of manufacturing technology.

When dry cleaning the inside of an apparatus in which an electrostatic chuck is formed in this manner, the surface of the insulating layer on which the substrate is attracted and held is covered with a protective plate made of sputtered Al on both sides of the same member as the substrate to be processed. be exposed. This protective plate is carried in from a load lock chamber (not shown) adjacent to the reaction chamber 7, and can be subjected to a dry cleaning process following the film forming process without opening the reaction chamber 7 to the atmosphere. Further, the target substrate to be processed in this invention is a Si wafer, and even if both sides are covered with an Al sputtered film, the Al
It is lighter than the metal plate of the electrostatic chuck, and when the suction surface of the electrostatic chuck faces downward in the vertical direction, it is possible to more reliably suction and hold the protection plate.

An example of each procedure for film formation and cleaning using a plasma processing apparatus in which an electrostatic chuck is formed as described above will be shown below.

Microwaves with a frequency of 2.45 GHz are introduced from a microwave power supply (not shown) into the evacuated plasma generation chamber 3 through the waveguide 1 and the microwave transmission window 2, and the main By the coil 5, about 0.09 mm is generated near the microwave transmission window in the plasma generation chamber 3.
A magnetic field of T is formed, and N2 is supplied from the plasma generation gas introduction system 4.
O into the plasma generation chamber 3, S from the reaction gas introduction system 6
iH4 was introduced into the reaction chamber at 30 SCCM and 15 S, respectively.
When supplied at the CCM flow rate, first in the plasma generation chamber 3, the microwave power is efficiently absorbed by the plasma generation gas due to the interaction between the microwave and the magnetic field near the microwave transmission window, and this plasma is converted into plasma. , moves toward the substrate 9 along the divergent magnetic field formed by the main coil 5, decomposing and activating the reaction gas SiH4 supplied into the reaction chamber 7. On the other hand, in the reaction chamber 7, a cusp magnetic field having a cusp surface at an optimal position for film formation is formed by the main coil 5 and the sub-coil 15 connected in series with the main coil 5. and the frequency is 400kHz, which is supplied to the electrostatic chuck 11.
, The RF bias with a power of 800 W equalizes the plasma density on the front side of the substrate 9, and the negative bias potential appearing on the substrate 9 injects O+ in the plasma into the substrate to activate the substrate surface reaction. A SiO film with good film thickness distribution and film quality is formed. The film thickness distribution is the same as the conventional 4
A distribution of 2-3% was obtained for ~5%. However, at this time, the SiO film is also deposited on the ring-shaped metal surface around the substrate.

Then, after processing 50 substrates 9 and depositing a film on the ring-shaped metal surface to a thickness of about 20 μm, a dry cleaning process is started. This process is the first
S as etching gas for 100 minutes as a step.
F6 is supplied into the plasma generation chamber 3 at a flow rate of 100 SCCM to generate ECR (electron cyclotron resonance) plasma, and the direction of the current in the subcoil 15 is reversed to create a mirror magnetic field within the device to generate active ions and radicals. is actively supplied to the side wall of the reaction chamber 7,
To effectively remove a film deposited on a side wall by etching. Second
By supplying SF6 at a flow rate of 50 SCCM and RF power of 600 W for 30 minutes as a step, active ions and radicals are supplied mainly to the ring-shaped metal surface, and the deposited film is effectively etched. As the third step, by switching SF6 to N2 O and supplying SiH4 into the reaction chamber 7, a 1 μm thick film is formed inside the device to prevent gas release from the internal surface of the device and scattering of particles. Then, the cleaning process is completed.

[0024]

Effects of the Invention As described above, in the present invention, an electrostatic chuck is used on the substrate table in the plasma processing apparatus,
The electrostatic chuck is covered with a ring-shaped metal surface having a ring-shaped opposing surface that faces the suction electrode with a significant width between the insulation layer and the outer diameter of the suction electrode. Because of this structure, when an RF power source is connected to the attraction electrode of the electrostatic chuck, a negative bias potential approximately equal to that of the substrate is generated on this metal surface as well. Since the ring-shaped metal surface shields the peripheral edge of the attraction electrode from the substrate, the electric field on the peripheral edge of the substrate is made uniform, and an electric field distribution is formed on the metal surface in which the electric field strength increases in the radial direction. , it is possible to form a film with uniform thickness and quality over the entire surface of the substrate from the center to the periphery.

Further, the metal surface covering the peripheral edge of the insulating layer surface of the electrostatic chuck in a ring shape is arranged so that the height thereof is lower than the surface of the insulating layer inside the metal surface, and the inner diameter is similar to that of the substrate to be processed. By forming the insulating layer to be smaller than the diameter, a film will not be deposited on the periphery of the insulating layer surface, and the inside of the device will not be contaminated by carbon, sodium, and other heavy metals contained in the insulating layer during cleaning. There is no. For example, when cleaning or removing a SiO film deposited inside the device, an RF bias is applied to the electrostatic chuck to supply a large amount of F+ in the fluorine-based cleaning gas to the SiO film deposited on the ring-shaped metal surface. The SiO film can be removed at an etching rate that is 3 to 10 times higher than when the peripheral edge of the insulating layer surface is exposed. As a specific example, 100
It has become possible to shorten the time from about a minute to about 30 minutes.

During dry cleaning inside the device, the surface of the insulating layer of the electrostatic chuck is covered with a protective plate made by vapor-depositing aluminum on both sides of the same substrate as the substrate to be processed, so that the protective plate is lighter than a metal plate. Therefore, especially in the case where the device performs processing with the surface of the substrate to be processed facing vertically downward, the protection plate is reliably adsorbed and there is no possibility that the insulating layer will be erroneously attacked by the etching gas. . Therefore, there is no risk of contamination within the device due to carbon, sodium, and other heavy metals in the insulating layer, and the yield of manufactured semiconductor devices is improved by avoiding contamination of the substrate with these substances during the next film formation. Can be done.

Furthermore, by forming the metal surface that covers the peripheral edge of the surface of the insulating layer of the electrostatic chuck in a ring shape with a metal sputtered film, the metal surface can be formed with high dimensional accuracy and with ease in terms of manufacturing technology. can.

As described above, according to the present invention, a film with uniform thickness and quality can be formed on the entire surface of the substrate without contaminating the substrate, and cleaning can be performed at high speed. Effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the structure of a plasma processing apparatus according to the present invention.

FIG. 2 is a diagram showing an embodiment of an electrostatic chuck structure constituting a substrate stage of a plasma processing apparatus according to the present invention, and FIG. The overall configuration diagram of the board stand is shown in the same figure (b
) is an enlarged view of part A in figure (a).

[Fig. 3] A vertical cross-sectional view showing an example of the configuration of a conventional plasma processing apparatus.

[Fig. 4] A vertical cross-sectional view showing an example of a structure different from that in Fig. 3 of a conventional plasma processing apparatus.

[Explanation of symbols]

2 Microwave transmission window 3 Plasma generation chamber 5 Main coil 7 Reaction chamber 8 Plasma drawer window 9 Substrate (substrate to be processed) 10　　　　PCB stand 11 Electrostatic chuck 11A Suction electrode 12 Metal surface 15 Sub coil 20 RF power supply

Claims (4)

[Claims] Claims: 1. An axially symmetrical plasma generation chamber which is provided with a microwave transmission window and a plasma extraction window on both end faces, is coaxially surrounded by a main coil, and has an electron cyclotron resonance magnetic field region formed therein; and the plasma extraction chamber. A reaction chamber that communicates with a plasma generation chamber through a window and has a substrate stand therein that holds a substrate to be processed, and an RF
In a plasma processing apparatus that is equipped with an RF power supply that applies a bias and performs processing such as film formation or etching on the surface of a substrate to be processed using plasma generated in a plasma generation chamber, the substrate table has an outer diameter covered with A common flat insulating layer is formed on the same side of a plurality of electrodes such as two semicircular plate electrodes arranged in one plane so as to form an attraction electrode larger than the diameter of the processing substrate. An electrostatic chuck is used which is embedded in an insulator and sucks and holds the substrate to be processed in close contact with the surface of the insulating layer by electrostatic attraction, and the peripheral edge side of the surface of the insulating layer is attached to the insulating layer. 1. A plasma processing device characterized by being covered with a ring-shaped metal surface having a larger outer diameter than the suction electrode and having a ring-shaped opposing surface facing the suction electrode with a significant width through the plasma processing apparatus. 2. In the plasma processing apparatus according to claim 1, the metal surface covering the peripheral edge of the surface of the insulating layer of the electrostatic chuck in a ring shape has a height higher than the surface of the insulating layer inside the metal surface. 1. A plasma processing apparatus characterized in that the plasma processing apparatus is formed so that the inner diameter thereof is smaller than the diameter of a substrate to be processed. 3. The plasma processing apparatus according to claim 2, wherein the surface of the insulating layer on the inside of the ring-shaped metal surface, on which the substrate to be processed is suctioned and held in close contact, is a film attached to the inside of the apparatus. 1. A plasma processing apparatus characterized in that during dry cleaning in which the same substrate as the substrate to be processed is removed using an etching gas, the substrate is covered with a protective plate made by vapor-depositing aluminum on both sides of the same substrate. 4. The plasma processing apparatus according to claim 1 or 2, wherein the metal surface covering the peripheral edge of the insulating layer surface of the electrostatic chuck in a ring shape is formed as a metal sputtered film. plasma processing equipment.