JPH0786381A - Electrostatic chuck - Google Patents

Abstract

PURPOSE:To set an electrostatic chuck sheet equal in pressure to apply. CONSTITUTION:Electrostatic chuck sheets 4a and 4b are provided onto the mounting surface of a suscepter 6 to attract and hold a work W by an electrostatic force, and a feed sheet is inserted into a feed slit 10 provided to the suscepter 6 for the formation of an electrostatic chuck, wherein a blocking member 86 is provided to the feed slit 10 to prevent the mounting surface of the suscepter 6 from communicating with the other surface. By this setup, the chuck sheets 4a and 4b can prevented from being exerted by a large differential pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck having an electrostatic chuck sheet.

[0002]

2. Description of the Related Art Generally, in a part of a semiconductor manufacturing process, for example, a plasma processing apparatus is used to perform various kinds of processing such as plasma etching on a semiconductor wafer as an object to be processed. In this type of processing apparatus, a holding means for holding and fixing a semiconductor wafer to be processed in order to prevent it from moving during processing, such as a mechanical clamp or an electrostatic chuck using electrostatic force. Is provided.

The structure of a conventional electrostatic chuck will now be described with reference to FIGS. 7 to 9. The electrostatic chuck 2 has an insulating electrostatic chuck sheet 4 made of, for example, a polyimide resin and a circular circle made of, for example, aluminum. It is composed of a columnar susceptor 6. A thin conductive film 8 such as a copper foil is enclosed in the electrostatic chuck sheet 4 over substantially the entire surface thereof to form a circular sheet as a whole, and the susceptor 6 is provided.
Is fixed to the mounting surface, which is the upper part of, by an adhesive or the like, and by applying a high DC voltage to the conductive film 8,
The electrostatic force generated attracts and holds the semiconductor wafer W on the upper surface of the sheet.

In order to apply a direct current high voltage to the conductive film 8 of the electrostatic chuck sheet 4, an aluminum susceptor 6 is formed by penetrating a power supply slit 10 having a length of about 1 cm in the thickness direction. As with the electrostatic chuck sheet 4, a power feeding sheet 14 having a power feeding film 12 such as copper foil enclosed in an insulating state is inserted into the slit 10. Then, the upper and lower ends of the power feeding sheet 14 are bent in the surface direction of the susceptor to form a U-shape as a whole, and the insulating film of the electrostatic chuck sheet 4 and the insulating film of the power feeding sheet 14 opposite thereto are partially removed. Then, the conductive film 8 of the chuck sheet 4 and the power feeding film 12 of the power feeding sheet 14 are electrically connected via the connection conductor 16 made of, for example, a conductive paste (see FIG. 8).

A portion of the insulating film is also removed from the lower portion of the power feeding sheet 14, and a connection conductor 18 made of a conductive paste is embedded in the lower portion of the insulation film. The connection conductor 18 is provided with a spring or the like from the susceptor support 20 side. A power supply pin 24, which is biased upward by the elastic member 22, is in contact with the power supply pin 24 to supply electric power from a DC high voltage source (not shown).

By the way, the processing temperature of the wafer is changed from a low temperature of -150 ° C. to a high temperature of about + 100 ° C. according to the processing content, and the cold heat or warm heat for that purpose is supplied from the susceptor support base 20 side. , A heat conductive gas having a predetermined pressure, for example, atmospheric pressure or about 10 Torr, is supplied between the susceptor support 20 and the susceptor 6 or between the susceptor 6 and the electrostatic chuck sheet 4 to efficiently cool or transfer heat. It is supposed to be done.

In particular, in the structure shown in the drawing, when the atmosphere at the contact portion between the power supply pin 24, which is a power supply point of a high voltage of 1 to 2 KV, and the connection conductor 18 of the power supply sheet 14 is in a vacuum or low pressure state. Discharge may occur depending on the state of the contact resistance at the contact portion. Therefore, in order to prevent this, the atmosphere is introduced between this portion, that is, between the susceptor support 20 and the susceptor 6 to maintain the atmospheric pressure. An O-ring 26 is interposed between the support 20 and the susceptor 6 so that the atmosphere does not leak to the vacuum processing chamber side. In order to improve the heat transfer between the wafer W and the chuck, He gas of about 10 Torr is also supplied to this interface.

[0008]

By the way, in such a conventional chuck structure, it is possible to prevent an abnormal discharge phenomenon from occurring at the power feeding point between the power feeding pin 24 and the power feeding sheet 14 as described above. To support the susceptor 20
Since atmospheric pressure is introduced between the susceptor 6 and the susceptor 6, the atmosphere reaches the upper side through the gap of the power feeding slit hole 10 formed for inserting the power feeding sheet 14, so that the slit hole 10 The electrostatic chuck sheet 4 on the upper side receives a pressure difference P1 of about 1 atm from the lower side as shown in FIG. The sheet 4 is peeled off from the mounting table of the susceptor 6 and partially bulges upward, and the protrusion 2
There was a problem that 8 was formed.

Usually, in order to fully exhibit the function of the electrostatic chuck, the flatness of the sheet surface must be secured to some extent and the degree of adhesion with the wafer must be good. The height H1 of 28 becomes larger than a limit value for ensuring good adhesion, for example, 23 μm, and as a result, a problem that the function of the electrostatic chuck is not fully exhibited occurs. Was there. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide an electrostatic chuck that does not apply a differential pressure to an electrostatic chuck sheet.

[0010]

In order to solve the above problems, the present invention provides an electrostatic chuck sheet for attracting and holding an object to be processed with an electrostatic force on the mounting surface of the susceptor, and the susceptor is provided with the electrostatic chuck sheet. In an electrostatic chuck formed by forming a power feeding slit penetrating in the thickness direction and inserting a power feeding sheet for feeding power to the electrostatic chuck sheet in the slit, the power feeding slit is closed. It is configured to form a blocking member for blocking communication between the mounting surface side of the susceptor and the opposite surface side thereof.

[0011]

According to the present invention, since it is configured as described above, the power feeding sheet is inserted into the power feeding slit formed in the susceptor, and the blocking member is provided in this slit, so that the susceptor is opposite to the mounting surface side. Cut off communication with the surface side. As a result, the differential pressure is not applied to the front surface and the back surface of the electrostatic chuck sheet, and the electrostatic chuck sheet is not partially swollen.

According to the second aspect of the present invention, the power feeding sheet is inserted through the power feeding slit formed in the susceptor, and further,
Since the slit seal member is filled in the slit, the communication between the mounting surface side of the susceptor and the opposite side thereof, that is, the atmosphere side is blocked. As a result, no differential pressure is applied to the front surface and the back surface of the electrostatic chuck sheet, which prevents the electrostatic chuck sheet from partially bulging.

According to the third aspect of the present invention, the feeding sheet is inserted through the feeding slit formed in the susceptor, and the closing sheet member is provided so as to cover the opening on the side opposite to the mounting surface of the slit. Moreover, since the communication hole that communicates with the slit is formed in the electrostatic chuck sheet corresponding to the slit, the space below the susceptor and the inside of the slit are blocked, and the atmospheric pressure below the susceptor does not enter the slit.
Since the pressure in the slit becomes the same as the pressure inside the processing chamber through the communication hole, no differential pressure is applied to the front and back surfaces of the electrostatic chuck sheet, and it does not bulge partially.

[0014]

An embodiment of an electrostatic chuck according to the present invention will be described below in detail with reference to the accompanying drawings. 1 is a sectional view showing a plasma processing apparatus to which the electrostatic chuck according to the present invention is applied, FIG. 2 is a sectional view showing a main part of the electrostatic chuck according to the present invention, and FIG. 3 is a sectional view of the electrostatic chuck shown in FIG. It is a top view of a susceptor before providing an electrostatic chuck sheet. The same parts as those shown in FIGS. 7 to 9 are designated by the same reference numerals. In this embodiment, a case where the electrostatic chuck according to the present invention is applied to a plasma etching apparatus will be described.

The plasma etching apparatus 30 has a processing chamber 36 composed of an inner frame 32 and an outer frame 34 made of a material such as aluminum. The inner frame 32 is
A cylindrical wall portion 32A, a bottom portion 32B provided at a slight distance above the lower end of the cylindrical wall portion 32A, and an outer flange portion 3 provided on the outer periphery of the lower end of the cylindrical wall portion 32A.
2C and. On the other hand, the outer frame 34 includes a cylindrical wall portion 34A and a ceiling portion 34B, and the outer flange portion 3 covers the inner frame 32 in an airtight manner.
It is placed on 2C.

Above the cylindrical wall portion 34A of the outer frame 34, a gas capable of introducing a processing gas, such as HF gas, from a processing gas source (not shown) into the processing chamber 36 through a mass flow controller (not shown). A supply line 38 is provided. Further, a gas exhaust pipe line 40 is provided below the other side of the cylindrical wall portion 34A so that a vacuum pump (not shown) can evacuate the gas.

Above the ceiling portion 34B of the outer frame 34, a magnetic field generator for forming a horizontal magnetic field on the surface of an object to be processed, for example, a semiconductor wafer W, for example, a permanent magnet 42.
Is rotatably provided, and a magnetron discharge can be generated by forming a horizontal magnetic field by the magnet and an electric field orthogonal to the horizontal magnetic field.

In the processing chamber 36, a susceptor assembly 44 for mounting and fixing an object to be processed, for example, the semiconductor wafer W is arranged. This susceptor assembly 44
Through the plurality of insulating members 46, the bottom 32 of the inner frame 32
Since an O-ring 48, for example, is interposed as an insulating member between the side surface of the susceptor assembly 44 and the cylindrical wall portion 32 of the inner frame 32, the susceptor is placed on the B side. The assembly 44 is configured to be held in an insulated state from the inner frame 32 and the outer frame 34, which are grounded externally.

The susceptor assembly 44 is made of, for example, aluminum and has a three-layer structure in the illustrated example. The susceptor 6 and the susceptor support base 20 for supporting the susceptor 6 are provided under the susceptor 6. It is composed of a jacket housing 50. The electrostatic chuck sheet 4 is attached to the mounting surface on the upper surface of the susceptor 6 with an adhesive or the like to form the electrostatic chuck 52. Then, the semiconductor wafer W as the object to be processed is suction-held on the electrostatic chuck sheet 4.

The susceptor support 20 is provided with a temperature adjusting device, such as a heater 54, for adjusting the temperature of the semiconductor wafer W. The heater 54 is connected to a heater controller (not shown), and is configured to perform temperature control according to a signal from a temperature monitor (not shown) that monitors the temperature of the susceptor 6.

The susceptor 6 is the susceptor support base 2
It is removably fixed to 0 by using a connecting member such as a bolt 56. With this configuration, the high frequency power source 58
Separately from the susceptor support 20 connected to
It becomes possible to replace only the above 6 parts of the susceptor,
Maintenance of the device becomes easy.

As described above, since the O-ring 48 is interposed between the side wall of the susceptor 6 and the inner surface of the cylindrical wall portion 32A of the inner frame 32, the processing gas introduced into the processing chamber is treated as described above. It does not reach below the susceptor support 20, and contamination of these parts is prevented.

Inside the cooling jacket accommodating table 50, a cooling jacket 62 for accumulating a coolant 60 such as liquid nitrogen is installed. The cooling jacket 62 is connected to a liquid nitrogen source 68 by a pipe 64 via a valve 66. A liquid level monitor (not shown) is arranged in the cooling jacket 62, and by opening and closing the valve 66 in response to a signal from the liquid level monitor, the coolant 60, for example, the liquid, in the cooling jacket 62 is opened. It is configured to control the supply amount of nitrogen. Further, the bottom surface of the inner wall of the cooling jacket 62 is formed, for example, in a porous form so that nucleate boiling can occur, and the liquid nitrogen therein can be maintained at a predetermined temperature, for example, -196 ° C. .

The thus constructed susceptor assembly 44 is electrically insulated from the inner frame 32 and the outer frame 34 constituting the processing chamber 36 by the insulating members 46 and 48, and has the same electrical polarity. The high frequency power source 58 is connected to the susceptor support 20 via a matching device 100. Thus, the susceptor assembly 44 and the ceiling portion 34B of the outer frame 34 which is grounded constitute an opposing electrode, and by applying high frequency power, it is possible to generate a plasma discharge between the electrodes, that is, in the processing chamber 36.

Further, between the susceptor 6 in the upper layer of the susceptor assembly 44 according to the present embodiment and the susceptor support base 20 in the middle layer provided with the heater 54, and between the susceptor support base 20 and the lower cooling jacket receiving portion 50. There are gaps 70 and 72 formed between the two, respectively, and these gaps are airtightly constituted by sealing members 74 and 76 such as O-rings. For example, it is open to the atmosphere. Instead of opening to the atmosphere, an inert gas such as He gas or Ar gas may be supplied at a predetermined pressure, for example, 1 atm.

The gaps 74 and 76 are 1 to 100 μm.
And is preferably about 50 μm. The medium enclosed in these gaps 74 and 76 can transfer the cooling heat from the cooling jacket 62 with a minimum heat loss, and yet prevent discharge at the power feeding point as described later.

On the other hand, the electrostatic chuck 52 according to the present invention is
As described above, the electrostatic chuck sheet 4 made of, for example, polyimide having an insulating property and the cylindrical susceptor 6 made of aluminum, for example, are used. The electrostatic chuck sheet 4 is formed by laminating a pair of polyimide resin films 4A and 4B, in which a thin conductive film 8 such as a copper foil is formed.
Is enclosed in an insulated state. The power supply sheet 1 is formed by penetrating the susceptor 6 made of aluminum on the conductive film 8.
A DC voltage is applied via 4.

That is, the thickness L1 of the susceptor 6 is about 20 m.
The thickness is about m, and a feed slit 10 having a substantially rectangular cross section is formed to penetrate in this thickness direction as shown in FIG. The cross-sectional area of the slit 10 is the power feeding sheet 1 described above.
4 is large enough to be inserted, and the vertical length L in FIG.
2 and the lateral length L3 are, for example, 12 mm and 2 m, respectively.
It is set to m.

Similar to the electrostatic chuck sheet 4, a power feeding film 12 such as a copper foil is provided inside the power feeding slit 10.
The power feeding sheet 14 enclosed by pasting the two insulating films 14A and 14B together is inserted, and the upper and lower ends thereof are bent in the surface direction of the susceptor 6 to be formed in a U shape as a whole. Since the power feeding sheet 14 is made of a flexible material such as polyimide resin as described above, it is not damaged by bending.

At this time, the upper bent portion 80 of the power feeding sheet 14
The lengths L4 of A (the mounting surface side of the susceptor) and the lower bent portion 80B (the surface opposite to the mounting surface side) are set to the same length, for example, about 10 mm. The insulating film 14A and the resin film 4A in a portion where the bent portion 80A and the electrostatic chuck sheet 4 face each other are formed into a conductive film 8 having a circular size with a diameter L5 of about 2 mm.
The conductive film 8 of the chuck sheet 4 and the power feeding film 12 of the power feeding sheet 14 are electrically connected to each other with a connecting conductor 16 made of, for example, a silver conductive paste interposed therebetween.

Further, the lower bent portion 80B of the power feeding sheet 14
A part of the insulating film 14A is removed so as to reach the power supply film 12 by a circular size having a diameter of about 2 mm, and the connection conductor 18 made of a similar silver conductive paste is embedded in this part.

The connecting conductor 18 is provided with a feeding pin urged upward, that is, toward the susceptor 6 by a resilient member 22 such as a spring in a pin hole 80 formed in the susceptor supporting base 20 located below the connecting conductor 18. The tip of 24 abuts, and the pin 24 and the power feeding film 12 of the power feeding sheet 14 are electrically connected. The power supply pin 24 is connected to a high voltage DC source 84 via a conductive wire 82 as shown in FIG. 1, and is connected to the conductive film 8 of the electrostatic chuck sheet 4 by, for example, 2.
It is configured so that a DC voltage of 0 KV can be applied.

The electrostatic chuck sheet 4 is firmly joined to the mounting surface of the susceptor with, for example, an epoxy adhesive, and the power feeding sheet 14 is also similar to the susceptor side at the upper bent portion 80A and the lower bent portion 80B. Are bonded to each other with, for example, an epoxy adhesive. In addition, as described above, in the gap 70 formed between the lower surface of the susceptor 6 and the upper surface of the susceptor support 20, in order to improve heat transfer of this portion, and at the power feeding point P2 of the power feeding pin 24. Atmospheric pressure of 1 atm is introduced to suppress the discharge.
Therefore, the atmosphere may flow into the power supply slit 10 formed in the susceptor 6 and adversely affect the electrostatic chuck film 4. However, in the present embodiment, in order to prevent this, a slit seal member 86 such as an adhesive is entirely injected into the power feeding slit 10 through which the power feeding sheet 14 is inserted to close it. is doing. As the slit seal member 86, -15
Any adhesive may be used as long as it is stable over a temperature range of 0 ° C. to room temperature or + 100 ° C., for example, an epoxy adhesive or an organic or inorganic adhesive is used. In the above, Armstrong Epoxy A-12 (trademark) was used. Further, engineering plastics, ceramics or the like may be used instead of or together with the adhesive.

The adhesive forming the seal member 86 is applied to the power feeding slit 10 of the susceptor 6 and the power feeding sheet 1.
4 is attached, and after the electrostatic chuck sheet 4 is attached to the mounting surface of the susceptor with an adhesive, a syringe or the like is opened from below the power supply slit 10, that is, from the opening 10A on the susceptor support base 20 side. Will be injected using the injection device. In addition, on the side wall of this etching device,
A gate valve (not shown) is provided and is connected to the load lock chamber via the gate valve.

Next, the operation of this embodiment configured as described above will be described. First, the semiconductor wafer W is housed in the processing chamber 36 by a transfer arm (not shown) through a gate valve (not shown), and is placed on the electrostatic chuck sheet 52 provided on the placement surface of the susceptor 6. A DC voltage of, for example, 2.0 KV is applied from the high voltage DC source 84 to the conductive film 8 of the electrostatic chuck sheet 52, and the wafer W is attracted and held by the Coulomb force due to polarization.

The inside of the processing chamber 36 is previously evacuated by a vacuum pump (not shown) connected to the gas exhaust pipe 40, and a processing gas, for example, HF gas, is supplied through the gas supply pipe 38. Is supplied while controlling the flow rate to maintain the process pressure in the processing chamber 36 at a process pressure, for example, about 10 ⁻¹ Torr, and at the same time, for example, 13.5 by the high frequency power source 58.
High frequency of 6MHz is the susceptor support 20 which is the lower electrode.
And to the susceptor 6. As a result, plasma is generated between the susceptor 6 and the ceiling portion 34B of the outer frame 34, which is the upper electrode, and at the same time, the permanent magnet 42 provided above the ceiling portion 34B is rotated so that plasma is generated in the vicinity of the wafer W. A magnetic field parallel to this surface is formed, and the wafer W is subjected to highly anisotropic etching.

At the time of the etching process of the wafer W, cold heat from the cooling jacket 62 provided in the cooling jacket housing 50 is transferred to the susceptor support 20, the susceptor 6 and the wafer W in this order for low temperature etching. However, at this time, the heater 5 provided on the susceptor support 20
The processing temperature of the wafer W is controlled by controlling the heat generation amount of No. 4. In this case, the gap 72 between the cooling jacket housing 50 and the susceptor support 20 and the gap 70 between the susceptor support 20 and the susceptor 6 have good heat transfer properties. In order to prevent discharge at the power feeding point P2, for example, an atmosphere of 1 atm is introduced, and heat transfer efficiency to the wafer W is maintained.

On the other hand, the DC voltage from the high voltage DC source 84 is
It is applied to the conductive film 8 of the electrostatic chuck sheet 4 through the conductive path 82, the power feeding pin 24, the connection conductor 18, the power feeding film 12 of the power feeding sheet 14 and the connection conductor 16, and the upper portion of the power feeding pin 24 and the connection conductor. Since the atmosphere of 1 atm is introduced into the gap 70 where the feeding point P2, which is the contact point with 18, is introduced, the occurrence of discharge is prevented even if the contact resistance of this portion increases.

Although the flexible power feeding sheet 14 is inserted through the power feeding slit 10 formed in the susceptor 6, it is inevitable that a slight gap is generated in this portion.
A pressure difference of 1 atm may be applied to the electrostatic chuck sheet 4 through the gap during wafer processing. However, in this embodiment, since the slit sealing member 86 made of, for example, an epoxy adhesive is substantially completely injected and solidified as a closing member in the entire gap in the power feeding slit 10, the inside is completely blocked. Therefore, no atmospheric pressure is applied to the back surface of the electrostatic chuck sheet 4.

Therefore, unlike the conventional structure, even if the inside of the processing chamber 36 is depressurized because the wafer is being processed, the chuck sheet 4 does not have a portion to which a pressure difference of 1 atm is applied, and the chuck sheet 4 has a pressure difference. It is possible to prevent partial bulging. Therefore, the flatness of the electrostatic chuck sheet 4 is maintained high, and the suction holding function is not deteriorated. Further, when He gas for heat transfer of about 10 Torr is supplied to the back surface of the electrostatic chuck sheet 4, a pressure difference corresponding to this is applied to the electrostatic chuck sheet 4. Is much smaller than at atmospheric pressure, so there is no problem.

In the above embodiment, the slit seal member 86 is filled all over the inside of the power feeding slit 10 to ensure the shutoff from the atmosphere. However, the present invention is not limited to this. As shown in FIG. 4, only the lower opening 10A of the power feeding slit 10 may be closed by the slit seal member 86. In this case, 1 atmosphere of air may be trapped in the remaining gap 88 in the power feeding slit 10 in the manufacturing process, but the electrostatic chuck sheet 4 corresponding to the upper opening 10B of the power feeding slit 10 is processed. It is preferable to form a communication hole 90 that communicates with the inside of the chamber 36. As a result, the processing chamber 36 and the inside of the power feeding slit 10 are communicated with each other through the communication hole 90, so that the pressure is the same, and no differential pressure is generated in the electrostatic chuck sheet 4 even during wafer processing.

Further, although the slit seal member 86 made of an adhesive is used as the closing member and is provided in the power feeding slit 10 in the above-mentioned embodiment, the present invention is not limited to this. As shown, the closing sheet member 92 may be used as the closing member.

That is, for example, a circular closing sheet member 92 is formed so as to completely cover the entire lower opening 10A of the power feeding slit 10 formed in the susceptor 6. The closing sheet member 92 is made of, for example, a polyimide-based insulating film, and an adhesive is applied over the entire surface of the closing sheet member 92. There is. The sheet member 92 is not limited to a polyimide film, and may be any insulating film that can withstand a pressure difference of about 1 atm. Sheet member may be used.

The shape of the closing sheet member 92 is not limited to the circular shape, and any shape may be used as long as it can cover the lower opening 10A. Further, a through hole having a diameter of about 2 mm is formed in the closing sheet member portion corresponding to the tip of the power supply pin 24 so as to embed the conductive paste. By embedding the conductive paste in this portion, the connecting conductor 18 is formed.
Are configured. Then, a DC high voltage is applied to the electrostatic chuck sheet 4 side via the power feeding sheet 14 by bringing the power feeding pin 24, which is biased from below, into contact with the connection conductor 18.

In this case, a gas of about 1 atm may be filled in the slight gap 88 remaining in the power feeding slit 10. Therefore, in order to remove the gas, the power feeding slit 10 is removed in the same manner as shown in FIG. A communication hole 90 that communicates with the inside of the processing chamber 36 is formed in the electrostatic chuck sheet 4 corresponding to the upper opening 10B, so that the inside of the processing chamber 36 and the inside of the slit 10 are always at the same pressure.

In the case of such a configuration, during processing, the processing chamber 36 and the gap 88 between the power supply slits 10 communicating with the processing chamber 36 have a low process pressure, but the susceptor 6 and the susceptor support 20 are separated from each other. The gap 70 is the feeding point P
A gas of about 1 atm is introduced to prevent discharge at 2. However, since the lower opening 10A of the power feeding slit 10 is covered and closed by the closing sheet member 92, the gas of 1 atm does not enter the gap 88, and therefore, the electrostatic chuck sheet 4 is prevented. The differential pressure is not applied between the front and back sides, and it is possible to prevent this from bulging upward.

In this case, during the wafer processing, the gap 88 of the power feeding slit 10 has a process pressure, and the gap 70 below the closing sheet member 92 has a substantially atmospheric pressure. A pressure of about 1 atm is applied to the sheet member 9 located at the lower opening 10A of the slit.
2 tends to swell slightly upward as shown by the imaginary line, but there is no problem because it does not affect the electrostatic chuck sheet 4 at all.

When a plurality of grooves for supplying a heat transfer gas of, for example, about 10 Torr are formed on the mounting surface of the susceptor 6, that is, the back surface of the electrostatic chuck sheet, the grooves are used for power supply. The upper opening of the slit may be communicated with each other, and in this case, the communication hole 90 may not be provided in the electrostatic chuck sheet 4. In the above embodiments, the case where the electrostatic chuck of the present invention is applied to the plasma etching apparatus has been described as an example, but the present invention is not limited to this and is applicable to a processing apparatus that needs to adsorb an object to be processed. Of course, all are applicable.

[0049]

As described above, according to the electrostatic chuck of the present invention, the following excellent operational effects can be exhibited. Since the power feeding slit is provided with a blocking member to block the communication between the mounting surface side of the susceptor and the opposite surface side, the electrostatic chuck sheet formed on the mounting surface side is partially connected via the power feeding slit. It is possible to prevent a large differential pressure from being applied. Therefore, it is possible to prevent the electrostatic chuck sheet from partially bulging, and it is possible to maintain the flatness of the chuck sheet and maintain the suction holding function of the chuck sheet high.

[Brief description of drawings]

FIG. 1 is a sectional view showing a plasma processing apparatus to which an electrostatic chuck according to the present invention is applied.

FIG. 2 is a sectional view showing a main part of an electrostatic chuck according to the present invention.

FIG. 3 is a plan view of a susceptor before the electrostatic chuck sheet of the electrostatic chuck shown in FIG. 2 is provided.

FIG. 4 is a sectional view showing a modified example of the electrostatic chuck of the present invention shown in FIG.

FIG. 5 is a cross-sectional view showing another modified example of the electrostatic chuck of the present invention.

6 is a plan view showing a positional relationship between a susceptor, a power feeding slit, and a closing sheet member before the electrostatic chuck sheet of the electrostatic chuck shown in FIG. 5 is provided.

FIG. 7 is a cross-sectional view showing a conventional electrostatic chuck.

FIG. 8 is an enlarged view showing a main part of the electrostatic chuck shown in FIG.

9 is a view showing a state where an electrostatic chuck sheet of the electrostatic chuck shown in FIG. 8 is swollen.

[Explanation of symbols]

 4 Electrostatic Chuck Sheet 6 Susceptor 8 Conductive Film 10 Feeding Slit 12 Feeding Film 14 Feeding Sheet 16, 18 Connection Conductor 20 Susceptor Support 24 Feed Pin 30 Plasma Etching Device 36 Processing Chamber 44 Susceptor Assembly 52 Electrostatic Chuck 58 High Frequency Power 84 High-voltage DC source 86 Slit sheet member (blocking member) 90 Communication hole 92 Blocking sheet member (blocking member) W Semiconductor wafer (processing target)

Claims (3)

[Claims] 1. An electrostatic chuck sheet for attracting and holding an object to be processed by electrostatic force is provided on a mounting surface of a susceptor, and a power feeding slit is formed in the susceptor so as to penetrate in the thickness direction. In an electrostatic chuck in which a power feeding sheet for feeding power to the electrostatic chuck sheet is inserted into the electrostatic chuck sheet, the power feeding slit is closed to cut off communication between the mounting surface side of the susceptor and the opposite surface side thereof. An electrostatic chuck characterized in that it is configured to form a closing member for 2. The electrostatic chuck according to claim 1, wherein the closing member is a slit seal member injected into the slit. 3. The closing member is a closing sheet member made of an insulating material and formed to cover the opening of the slit formed on the opposite side, and the electrostatic chuck sheet is provided with the power feeding member. The electrostatic chuck according to claim 1, wherein the electrostatic chuck is configured to form a communication hole communicating with the inside of the slit.