JPH09312281A - Wafer holding electrode body - Google Patents

Abstract

(57) Abstract: It is desired to provide a wafer holding electrode body that can be used in a wide temperature range and that does not cause inconvenience such as breakage even when a heating medium is used under high pressure. A wafer-holding electrode body 30 functions as an electrode for generating plasma when a high frequency is applied, and holds a wafer to adjust the temperature of the wafer. It has a plate-shaped metal electrode body 31. A groove-shaped flow groove 33 for flowing a heating medium for adjusting the wafer temperature is formed in a spiral shape on the electrode body 31, and a lid formed on the opening side of the flow groove 33 in the same shape as the opening side. By fitting the body 32, the opening side of the flow groove 33 is covered, and the space between the lid body 32 and the electrode body 31 is sealed. A supply port for supplying the heating medium is provided at one end of the circulation groove 33, and an outlet for discharging the heating medium is provided at the other end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in a semiconductor process that requires temperature control of a wafer, particularly a process of generating plasma in a vacuum container such as etching, CVD, and sputtering for processing. The present invention relates to a wafer holding electrode body.

[0002]

2. Description of the Related Art Semiconductor processes include etching and CV.
There are various processes such as D and sputtering. In these processes,
Each processing is performed by using a dedicated device for each. FIG. 5 shows an etching apparatus which is a typical one of such manufacturing apparatuses.

In FIG. 5, reference numeral 1 is a plasma etching apparatus. The plasma etching apparatus 1 includes a chamber 2 serving as an etching chamber, a gas supply means 3 for supplying an etching gas to the chamber 2, and an inside of the chamber 2. And an exhaust means 4 for exhausting gas.
In the chamber 2, a disk-shaped metal wafer holding electrode body 5 is provided at the bottom thereof. A high-frequency power supply 6 is connected to the wafer holding electrode body 5, whereby the wafer holding electrode body 5 functions as a lower electrode for generating plasma P in the chamber 2. That is, a high frequency power is applied to the wafer holding electrode body 5 from the high frequency power source 6, etching gas is further supplied from the gas supply means 3, and the inside of the chamber 2 is decompressed by the exhaust means 4, whereby the inside of the chamber 2 is reduced. The plasma P is generated.

An electrostatic chuck 7 for holding and fixing the wafer W is fixed on the wafer holding electrode body 5. The electrostatic chuck 7 is a disk-shaped one having a dielectric made of an insulating material such as ceramic and an electrode made of a dielectric polarizable conductor provided on the lower surface of the dielectric, and is connected to a high voltage power source (not shown). When the voltage is applied from this high voltage power source, the wafer W is held by exerting an adsorption force. Also,
A chiller 8 is connected to the wafer holding electrode body 5 via the electrostatic chuck 7 in order to control the temperature of the wafer W placed on the wafer holding electrode body 5. The chiller 8 is for flowing a cooling medium or a heating medium serving as a heating medium to the wafer holding electrode body 5, thereby adjusting the wafer holding electrode body 5 to a predetermined temperature.

The wafer-holding electrode body 5 is adjusted to the temperature of the heating medium by circulating the heating medium from the chiller 8. As a result, the temperature of the wafer W is adjusted as described above. For example, it has a screw type structure as shown in FIG. The wafer holding electrode body 5 shown in FIG. 6 comprises an electrode body 9 and a lid 10 fixed on the body.
The flow path 11 is formed in the electrode body 9 by hole drilling. The upper opening of the flow channel 11 is covered by the lid 10, so that the heating medium flowing through the flow channel 11 directly contacts the lid 10.

In addition, a flow path 11 is provided at the bottom of the electrode body 9.
A supply port 12 for supplying the heating medium and an outlet 13 for discharging the heating medium are provided so as to communicate with each other. The supply port 12 and the discharge port 13 are both connected to the chiller 8.
A supply port 12 is connected to the heating medium supply side of the chiller 8 and a discharge port 13 is connected to the heating medium return side of the chiller 8, whereby the heating medium from the chiller 8 is connected to the chiller 8 and the wafer holding electrode body. It is designed to circulate between 5 and 5. Lid 1
No. 0 is fixed to the electrode body 9 with screws 14, and a flow path 11 is provided between the lid 10 and the electrode body 9.
An O-ring 15 for the outer circumference is provided so that the heating medium flowing through does not leak. With such a configuration, the temperature of the wafer holding electrode body 5 is adjusted so that the temperature distribution of the whole is uniform because the heating medium from the chiller 8 flows in the flow path 11.

Further, as shown in the plan view of FIG. 7 and the side sectional view of FIG. 8, a pusher pin (for pushing up the wafer W placed through the electrostatic chuck 7 is attached to the wafer holding electrode body 5 as shown in FIG. Three holes 16 (not shown) and a hole 17 for inserting a sensor for measuring the temperature of the wafer W are formed. All of these holes 16 and 17 are holes that penetrate from the upper surface to the lower surface of the wafer holding electrode body 5, and the O-rings for holes are also provided around the holes 16 and 17 so that the heating medium does not leak from the respective holes. 18 is provided.

Further, as a wafer holding electrode body, FIG.
The sealing type structure shown in (1) is also known. FIG.
The wafer-holding electrode body 20 shown in FIG. 2 is composed of an electrode body 22 having a groove-shaped flow channel 21 formed therein and a lid 23 that covers the upper opening of the flow channel 21. The main body 22 and the main body 22 are sealed by electron beam welding. Sealing by electron beam welding is shown in Fig. 9.
As shown by the middle symbol S, it is formed not only on the outer peripheral portion of the electrode body 22 but also between the grooves that will be the flow channels 21, whereby the heating medium flowing through the flow channels 21 contacts the lid 23 and this. It flows along the direction of the flow path 21 without passing between the upper surface of the electrode body 22 and the upper surface.

[0009]

However, the wafer holding electrode bodies 5 and 20 have the following disadvantages. In the wafer holding electrode body 5 shown in FIGS. 6, 7, and 8, the outer circumference O-ring 15 and the hole O-ring 18 have different thicknesses and outer diameters, and of course, different crushing margins of the O-rings. There is. Therefore, these O-rings 15 and 18
If only the screws 14 attached to the outer peripheral portion of the wafer holding electrode body 5 are pressed against, the heating medium will easily leak.

Further, in order to send the hot medium from the chiller 8 to the wafer holding electrode body 5 and circulate the hot medium, a pressure is naturally applied to the hot medium. However, in the case of performing processing by making the inside of the chamber 2 into a substantially vacuum state by the exhaust means 4, the pressure difference between the inside of the chamber 2 which is the outside of the wafer holding electrode body 5 and the inside of the flow passage 11 is the heating medium. It becomes the pressure that is added to the pressure added to the atmospheric pressure and becomes large. And
Since the pressure difference becomes large as shown in FIG.
As shown in 0, the lid 10 rises up and the heating medium leaks from the holes 16 and 17 formed in the lid 10, which is a disadvantage. Further, since the O-rings 15 and 18 are provided between the electrode body 9 and the lid 10, the operating temperature range of the wafer holding electrode body 5 is limited to the narrow operating temperature range of the O-rings 15 and 18. Will end up.

On the other hand, the wafer holding electrode body 2 shown in FIG.
At 0, when a high-pressure heating medium is used, as shown in FIG. 11, the welded portion of the electron beam, that is, the seal portion S is broken and the lid body 23 rises up to bond to the upper surface of the lid body 23. The dielectric made of ceramic or the like of the electrostatic chuck 7 is destroyed. In order to prevent such destruction, normally, as shown in FIG. 12, the thickness t of the lid 23 is
Has a sufficient thickness (for example, 7 mm) to withstand a high-pressure heating medium. However, regarding the output intensity of electron beam welding, as the thickness of the lid 23 becomes thicker, the intensity of the electron beam reaching between the grooves forming the flow paths 21 of the electrode body 22 becomes smaller as shown by S in FIG. Therefore, if the lid 23 becomes thicker, the diameter L _{2 of the} welded portion becomes narrower, and it becomes impossible to withstand the high-pressure heating medium and is destroyed. By the way, when the diameter L _{1 of the} electron beam with which the upper surface of the lid 10 is irradiated is 2.5 mm, the diameter L of the welded portion is L.
₂ is 0.2 to 0.3 mm.

The present invention has been made in view of the above circumstances. An object of the present invention is to hold a wafer that can be used in a wide temperature range and does not cause inconvenience such as destruction even if a heating medium is used at high pressure. To provide an electrode body.

[0013]

A wafer holding electrode body of the present invention has a plate-shaped metal electrode body, and a groove shape for flowing a heating medium for adjusting a wafer temperature to the electrode body. Of the circulation groove is provided, and the opening side of the circulation groove is covered by fitting a lid body having the same shape as the shape of the opening side to the opening side of the circulation groove, and the lid body and the electrode body main body. The space between them is sealed, and the supply port for supplying the heating medium is provided on one end side of the flow groove, and the discharge port for discharging the heating medium is provided on the other end side, which is the means for solving the problems.

According to this wafer-holding electrode body, the electrode body is provided with a groove-shaped flow groove for flowing the heating medium, and the flow groove is covered by fitting the lid into the opening side of the flow groove. In addition, since the lid and the electrode body are sealed, sufficient airtightness is ensured, which eliminates the need to use an O-ring and thus enables use in a wide temperature range. In addition, since the lid is fitted into the flow groove and the gap between the lid and the electrode body is sealed, when manufacturing this, the sealing portion is the upper surface of the electrode body regardless of the thickness of the lid. Therefore, if the sealing is performed by, for example, electron beam welding, the intensity of the electron beam reaching the sealing portion becomes sufficiently large, and thus the sufficient sealing strength can be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The wafer holding electrode body of the present invention will be described in detail below with reference to embodiments. 1 and 2 are views for explaining a first embodiment of a wafer holding electrode body of the present invention, and FIG. 1 is an exploded perspective view showing a schematic configuration,
FIG. 2 is a side sectional view. In these drawings, reference numeral 30 denotes a wafer holding electrode body, and this wafer holding electrode body 3
0 is suitable for use in a semiconductor process that requires temperature control of the wafer W, such as the plasma etching apparatus 1 shown in FIG.

This wafer holding electrode body 30, like the wafer holding electrode body 5 shown in FIG. 6 and the wafer holding electrode body 20 shown in FIG. 9, generates plasma when a high frequency is applied. It functions as an electrode and controls the temperature of the wafer W by mounting it, and is composed of a metal electrode body 31 and a lid 32.

The electrode body 31 has a disk-like shape, and a flow groove 33 having a spiral shape in plan view is formed on the upper surface side thereof as shown in FIG. A lid 32 having the same shape as the opening side shape is provided in the circulation groove 33 so that the upper surface thereof is flush with the upper surface of the circulation groove 33 as shown in FIG. It is fitted into the opening side and sealed in that state. The flow groove 33 is thus covered with the lid 32 on the opening side to form the flow path 34 for flowing the heating medium. This flow path 34
A supply port 35 for supplying the heating medium is formed on one end side of the circulation groove 33, and an exhaust port 36 for discharging the heating medium is formed on the other end side thereof. These supply port 35 and discharge port 36 are
Supply pipe 3 for supplying and circulating a heating medium in the flow path 34
7 and a discharge pipe 38 are connected to each other, and to the supply pipe 37 and the discharge pipe 38, a temperature medium supply device (not shown) such as the chiller 8 shown in FIG. 5 is connected.

The sealing of the lid 32 fitted in the flow groove 33 is carried out by electron beam welding as shown in FIG. 2 in this embodiment. This electron beam welding is performed between the electrode body 31 and the lid 32 in a state where the lid 32 is fitted in the flow groove 33. Therefore, since the sealing portion S is exposed to the upper surface of the electrode body 31 regardless of the thickness of the lid 32, the electron beam reaching the sealing portion S can be obtained by performing the sealing by electron beam welding. Has a sufficient strength, whereby a sufficient sealing strength is secured between the electrode body 31 and the lid 32. Also,
Since the circulation groove 33 has a spiral shape and the lid body 32 also has a spiral shape, the sealing portion S between them substantially coincides with the entire side surface of the lid body 32 formed in a spiral shape,
Therefore, since the entire sealing area is increased, the bonding strength of the lid 32 to the electrode body 31 is sufficiently high.

Next, a method of using the wafer holding electrode 30 having such a configuration will be described as an example in which it is applied to the plasma etching apparatus 1 shown in FIG. In order to perform plasma etching using the wafer holding electrode 30, the electrostatic chuck 7 is fixed on the wafer holding electrode 30 in advance. Then, the wafer W is placed on the electrostatic chuck 7, and a high voltage is applied to the electrostatic chuck 7 to exert an adsorption force to fix the placed wafer W, and the inside of the chamber 2 is evacuated by the exhaust means. Reduce the pressure so that it is in a substantially vacuum state. Separately from this, the chiller 8 (heat medium supply device) connected in advance to the wafer holding electrode 30 supplies and circulates the heat medium (refrigerant) into the flow path 34 of the wafer holding electrode 30 to supply the wafer holding electrode. 30 is adjusted to a predetermined temperature.

Then, when the temperature of the wafer W is detected by a temperature detection sensor (not shown) provided on the electrostatic chuck 7 and it is confirmed that the temperature is stabilized at a predetermined temperature, a high frequency power source connected to the wafer holding electrode 30 in advance. By applying a high frequency to the wafer holding electrode 30 from 6 and supplying an etching gas into the chamber 2 from the gas supply means 3,
Plasma P is generated and plasma etching processing is performed.

At this time, the wafer holding electrode body 30 is
Since the lid body 23 is fixed to the electrode body 22 by the sealing by electron beam welding without providing the ring and the airtightness between them is secured, the processing temperature of the wafer W is the same as the conventional temperature range of the O-ring. Without being limited to
It can be set in a wide temperature range. In addition, in this wafer holding electrode body 30, the lid body 32 is fitted into the flow groove 33 and the lid body 32 and the electrode body body 31 are sealed by electron beam welding. Therefore, even if a high pressure medium is used as the heating medium, it is possible to prevent the inconvenience that the lid 32 rises up and the heating medium leaks.

FIG. 3 shows the second wafer holding electrode body of the present invention.
It is a figure for explaining an example of an embodiment, and is a top view of an electrode body for flowing especially a refrigerant as a heating medium. The wafer holding electrode body shown in FIG. 3 differs from the wafer holding electrode body 30 shown in FIGS. 1 and 2 in the shape of the flow groove formed in the electrode body. The electrode body of the second embodiment shown by reference numeral 40 in FIG. 3 is formed in a spiral shape in a state where the flow groove 41 is seen in a plan view, and the width w thereof is the flow groove 4
1 is formed so as to gradually widen from the supply port 42 side to the discharge port 43 side, that is, the supply port 4
The distribution groove 41 is formed in a gradually widened state so that the width w ₂ of the distribution groove 41 on the discharge port 43 side is wider than the width w ₁ of the distribution groove 41 on the 2 side. .

Although not shown, the lid in the second embodiment is also formed in the same shape as the opening side of the flow groove 41. Then, this lid also has the distribution groove 41.
In the state of being fitted in the opening side of, the flow groove 41 is covered and is sealed with the electrode body 40 by electron beam welding or the like.

In the wafer holding electrode body having such a structure, when a plasma treatment is carried out using the wafer holding electrode body in an apparatus as shown in FIG. ), A refrigerant (for example, He gas, Freon gas, or a polymer-based material) is caused to flow, and the temperature of the refrigerant gradually rises along the flow direction of the flow path due to the plasma treatment. That is, the coolant sufficiently cooled by the coolant supply device is supplied to the inside of the electrode body 40, is then subjected to heat exchange by receiving thermal energy of plasma or the like, and has a temperature higher than the temperature at the time of supply at the time of discharge. It will end up. Therefore, in the present embodiment, the width w of the circulation groove 41 is set to the supply port 4
Since it gradually widens from the 2 side to the outlet 43 side,
The contact area between the cooling medium and the lid body is increased on the side of the discharge port 43 where the cooling medium temperature rises, so that on the discharging port 43 side, heat exchange between the cooling medium and the surface of the wafer holding electrode body is performed in a large area, The cold heat is applied to the surface of the electrode body so as to offset the reduced amount.

Therefore, in this wafer holding electrode body, the surface can be cooled so as to have a substantially uniform temperature distribution without generating a large temperature gradient on the surface of the electrode body. Wafer W fixed to
Can be uniformly cooled without forming temperature unevenness, whereby the entire wafer W can be uniformly plasma-processed.

The wafer-holding electrode body is designed especially for the case where a coolant is used as the heating medium. However, when a heating medium is used as the heating medium, the electrode body 40 shown in FIG. The supply port and the discharge port may be used in reverse. In this way, the supply port and the discharge port are reversed and used, for example, 20
When plasma processing is performed using a heat medium made of silicon oil or the like at 0 to 300 ° C., the heat medium sufficiently heated by the heat medium supply device is supplied into the electrode body 40, and then heat energy such as plasma is supplied. When it is received, it is further heated, and when it is discharged, the temperature becomes higher than the temperature when it was supplied.

However, when using this heat medium, the supply port and the discharge port are reversed so that the width w of the flow groove 41 is increased.
Is gradually narrowed from the supply port (discharge port 43) side to the discharge port (supply port 42) side, the contact area between the heat medium and the lid becomes small on the discharge port side where the heat medium temperature rises, As a result, heat is exchanged between the heat medium and the surface of the wafer holding electrode body in a small area on the side of the discharge port (supply port 42), and heat is applied to the surface of the electrode body so as to offset the increase in the temperature of the heat medium. To be done. Therefore, in this wafer holding electrode body, even if a heating medium is used as the heating medium, the surface of the electrode body is heated so as to have a substantially uniform temperature distribution without generating a large temperature gradient on the surface of the electrode body. Therefore, the wafer W fixed on the wafer W can be uniformly heated without forming temperature unevenness, and thus the entire wafer W can be uniformly plasma-processed.

FIG. 4 is a third view of the wafer holding electrode body of the present invention.
It is a figure for explaining an example of an embodiment, and is a top view of an electrode body for flowing especially a refrigerant as a heating medium. The wafer holding electrode body shown in FIG. 4 is different from the wafer holding electrode body 30 shown in FIGS. 1 and 2 in the shape of the flow groove formed in the electrode body. The electrode body of the third embodiment shown by reference numeral 50 in FIG. 4 is formed in a spiral shape in a state where the flow groove 51 is seen in a plan view, and the flow groove 51 extends from the supply port 52 side to the discharge port 53. The distance d between the adjacent flow grooves 51 is gradually narrowed toward the side, that is, compared with the distance d ₁ between the flow grooves 51 on the supply port 52 side, the flow groove on the discharge port 53 side. The flow grooves 51 are formed such that the distance d ₂ between the 51 is narrower.

Although not shown, the lid in the third embodiment is also formed in the same shape as the opening side of the flow groove 51. And, this lid is also the distribution groove 51.
In the state of being fitted in the opening side of the above, it covers the flow groove 51 and is sealed with the electrode body 50 by electron beam welding or the like.

In the wafer holding electrode body having such a structure, when a plasma treatment is performed using the wafer holding electrode body by the apparatus shown in FIG. 5, a flow path (not shown) formed by the flow groove 41 is formed. ), The temperature of the refrigerant gradually rises along the flow direction of the flow path due to the plasma processing, as described above. In the present embodiment, however, the distance d between the flow grooves 51 is gradually narrowed from the supply port 52 side to the discharge port 53 side, so that the coolant is used for holding the wafer on the discharge port 53 side where the coolant temperature rises. The degree of contact with the surface portion of the electrode body (that is, the lid body) becomes high, whereby heat exchange between the coolant and the surface of the wafer holding electrode body is performed in a wide area on the side of the discharge port 43, and the coolant temperature becomes low. The cold heat is applied to the surface of the electrode body so as to offset the above.

Therefore, even in this wafer holding electrode body, similar to the wafer holding electrode body shown in FIG. 3, a substantially uniform temperature distribution can be obtained without generating a large temperature gradient on the surface of the electrode body. Since the surface of the wafer W can be cooled, the wafer W fixed on the surface of the wafer W can be uniformly cooled without forming temperature unevenness, whereby the entire wafer W can be uniformly plasma-processed.

Although the wafer holding electrode body is designed to flow a coolant as a heating medium, when a heating medium is used as the heating medium, it is similar to that shown in FIG. In the electrode body 50 shown in (1), the supply port and the discharge port may be used in reverse. In this way, when the supply port and the discharge port are used in reverse, and plasma processing is performed using a heating medium of 200 to 300 ° C., for example, the heating medium that has been sufficiently heated by the heating medium supply device is stored in the electrode body 50. After being supplied, it is further heated by receiving thermal energy of plasma or the like, and at the time of discharging, the temperature becomes higher than the temperature at the time of supplying.

However, when this heat medium is used, the supply port and the discharge port are reversed so that the distance d between the flow grooves 51 is changed from the supply port (discharge port 53) side to the discharge port (supply port). 5
2), the degree of contact with the surface portion (that is, the lid) of the wafer holding electrode body on the side of the discharge port where the temperature of the heat medium rises becomes low. On the (supply port 52) side, heat exchange between the heat medium and the wafer holding electrode body surface is performed in a small area, and heat is applied to the electrode body surface so as to offset the increase in the heat medium temperature. Therefore, in this wafer holding electrode body,
Even if a heating medium is used as the heating medium, the surface can be heated so as to have a substantially uniform temperature distribution without generating a large temperature gradient on the surface of the electrode body. The wafer W can be uniformly heated without forming temperature unevenness, and thus the entire wafer W can be uniformly plasma-processed.

In the above embodiment, the flow groove is formed in a spiral shape, but the present invention is not limited to this, and the flow groove may have an appropriate shape, such as a shape that crawls left and right in a plan view. Can be adopted.

[0035]

As described above, the wafer-holding electrode body of the present invention is provided with the groove-shaped flow groove for flowing the heating medium in the electrode body, and the lid is fitted on the opening side of the flow groove. Since this covers the flow groove and seals between the lid and the electrode body, it is possible to sufficiently secure airtightness between the lid and the electrode body. The use of rings can be dispensed with and thus can be used over a wide temperature range.

Further, since the lid body is fitted in the flow groove and the gap between the lid body and the electrode body is sealed, when manufacturing this, the sealing portion is removed regardless of the thickness of the lid body. It is exposed on the upper surface of the electrode body, and therefore, by performing sealing by, for example, electron beam welding, the intensity of the electron beam reaching the sealing portion can be made sufficiently large, which results in sufficient sealing strength. The resulting heating medium can thus be used at high pressure. Since the heating medium can be used at a high pressure in this way, it is possible to sufficiently separate the heating medium supply device (for example, a chiller or the like) and the main body of the wafer processing apparatus from each other. It is possible to widen the foot space of the installed clean room.

Further, the flow groove may be formed in a spiral shape in a plan view, and its width and interval may be changed from the supply port side to the discharge port side so that the surface temperature distribution of the wafer holding electrode body is made uniform. In this case, the plasma processing can be performed more uniformly, which is suitable for a process that is largely influenced by the wafer processing temperature.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a schematic configuration of a first embodiment of a wafer holding electrode body according to the present invention.

FIG. 2 is a side sectional view of the wafer holding electrode body shown in FIG.

FIG. 3 is a view showing a second embodiment of the wafer holding electrode body according to the present invention and is a plan view of the electrode body.

FIG. 4 is a diagram showing a third embodiment of the wafer holding electrode body according to the present invention and is a plan view of the electrode body.

FIG. 5 is a schematic configuration diagram of a plasma etching apparatus.

FIG. 6 is a side sectional view showing an example of a conventional wafer holding electrode body.

FIG. 7 is a plan view of the wafer holding electrode body shown in FIG.

FIG. 8 is a sectional view taken along the line AA of FIG. 7;

FIG. 9 is a side sectional view showing another example of a conventional wafer holding electrode body.

10 is a side sectional view for explaining a problem of the wafer holding electrode body shown in FIGS. 6, 7 and 8. FIG.

FIG. 11 is a side sectional view for explaining a problem of the wafer holding electrode body shown in FIG.

FIG. 12 is an enlarged cross-sectional view of an essential part for explaining a problem of the wafer holding electrode body shown in FIG.

[Explanation of symbols]

30 Wafer Holding Electrode Body 31, 40, 50 Electrode Body Main Body 32 Lid Body 33, 41, 51 Flow Groove 34 Flow Path 35, 42, 52 Supply Port 36, 43, 53 Discharge Port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/203 H01L 21/203 S 21/205 21/205

Claims (4)

[Claims] 1. An electrode body for holding a wafer, which functions as an electrode for generating plasma when a high frequency is applied, and which controls a temperature of the wafer, the plate body being made of metal. The electrode body has an electrode body, and a groove-shaped circulation groove for flowing a heating medium for adjusting the wafer temperature is provided in the electrode body, and the same shape as the shape of the opening side is formed on the opening side of the circulation groove. By covering the opening side of the flow groove by fitting the lid body and sealing between the lid body and the electrode body, a supply port for supplying the heating medium is provided at one end side of the flow groove, and An electrode assembly for holding a wafer, characterized in that a discharge port for discharging a heating medium is provided on an end side. 2. The wafer holding electrode body according to claim 1, wherein the flow groove is formed in a spiral shape in a plan view. 3. The wafer holder according to claim 2, wherein the width of the flow groove is formed so as to gradually increase from one side of the supply port or the discharge port of the flow groove to the other side. Electrode body. 4. The flow groove is formed such that a space between adjacent flow grooves is gradually narrowed from one side of the supply port or the discharge port of the flow groove to the other side. The electrode body for holding a wafer according to claim 2.