JP3505155B2 - Wafer holding device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for holding a wafer by using an electrostatic force in a wafer holding apparatus of a wafer processing apparatus. 2. Description of the Related Art A wafer holding apparatus of a conventional wafer processing apparatus is disclosed in Japanese Patent Application Laid-Open Nos. 2-148837 and 2-267.
As described in Japanese Patent No. 271, there is generally used a method in which the outer peripheral portion of a wafer is pressed and held by a claw-shaped member. When there is a member that comes into contact with the wafer surface, the contact portion has a problem that processing of the wafer is hindered, and the contact member also performs some processing together with the wafer.
As a result, a foreign matter source such as a reaction product may adhere to the contact member, or the contact member may be damaged, thereby generating foreign matter. Further, in a method of holding a wafer by using an electrostatic force (hereinafter, referred to as electrostatic attraction), a wafer is made of a dielectric material as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-157553. The wafer is placed on the electrostatic attraction unit, a high voltage is applied, and the wafer is held by the electrostatic attraction force. In this case, a member or the like pressing the wafer is not particularly described on the outer peripheral portion of the wafer. Therefore, the possibility of foreign matter generation by the contact member as in the above example is solved. However, the positional relationship between the wafer and the electrostatic attraction member is such that a step is provided on the electrostatic attraction member such that the wafer is located at the uppermost position (on the wafer processing space side) and the electrostatic attraction member is below the wafer. I have. With such a step,
It is also conceivable that the gas flow during wafer processing changes abruptly at the outer peripheral portion of the wafer, causing unevenness in wafer processing. In the example described in Japanese Patent Application Laid-Open No. 63-56920, a wafer is placed on a flat electrostatic attraction member. In this case, it is conceivable that the electrostatic chucking portion around the wafer may be damaged during wafer processing or a deposit may be generated, and when the next wafer is transported,
If the transfer accuracy is not sufficient, the wafer may be damaged or placed on the deposition portion, and there is a concern that a transfer error or a defect in wafer processing may occur. [0005] Regarding the transfer and transfer of the wafer, the wafer is moved up and down with a push-up pin or the like, the wafer is placed on the wafer holding unit, and then the wafer processing is performed at that position. The holding device may be moved up to this point. In the former case, there is no particular problem, but in the latter case, it is necessary to make the method of transporting the holding section highly reliable. In the example described in JP-A-59-186325, a shaft directly connected to a drive shaft of a cylinder installed on the atmosphere side passes through the decompression chamber, and the atmosphere and the decompression chamber are isolated by a seal ring. Further, a wafer holding device is connected to the penetrated shaft, and the wafer is moved up and down. The seal between the atmosphere and the decompression chamber when the wafer is up and down
It relies on sliding between the seal ring and the through shaft. In such a case, it is necessary to sufficiently take care not to damage the seal ring. Damage can cause foreign objects,
Careful attention is required especially when the wafer processing is performed in a corrosive gas or plasma because it may cause a leak. Further, in the example in which a metal block serving as a wafer holding device is movable, in the case of Japanese Patent Application Laid-Open No. 58-32410, a bellows connected to a wafer processing device is connected to the metal block via an insulator. However, in this example showing the wafer holding of the sputtering apparatus, the bellows is directly connected to the metal block from the inner wall of the container of the wafer processing apparatus (sputtering chamber), and the transfer mechanism member necessary for the wafer transfer is installed. Must be considered separately. [0006] The conventional wafer holding is
Because some member is in contact with the processing surface of the wafer,
There is a problem that foreign matter is easily generated from the contact portion and the vicinity thereof, the yield of wafer processing is reduced, and the wafer processing apparatus needs to be frequently cleaned, and the operation rate of the apparatus decreases. Also, when the wafer processing and the wafer transfer position are different, it was necessary to move the wafer holding device up and down. However, in order to shut off the wafer processing chamber and the outside world at this time, sliding of the elastomer seal portion is performed. As a result, there is a problem that foreign matter is easily generated. Further, when the wafer processing is performed in plasma, there is a problem that the elastomer seal is easily deteriorated. Another object of the present invention is to devise a method of manufacturing the wafer holding device to prevent leakage of the coolant for adjusting the temperature of the wafer or to eliminate the use of the elastomer seal for sealing the same. Further, in order to provide a wafer holding apparatus capable of reliably and uniformly performing a wafer processing which is an original object of the wafer processing apparatus, the present invention also aims at making the gas flow for the wafer processing uniform. And one of them. Further, in order to more reliably hold the wafer by the electrostatic force, even if the wafer slides in the horizontal direction, it is necessary to forcibly use the outer peripheral member. [0008] By providing a wafer holding apparatus with reduced foreign matter as described above and enabling uniform wafer processing, it is possible to improve the yield of wafer processing and improve the operation rate of the wafer processing apparatus. This is a problem to be solved by the present invention. A feature of the present invention is a wafer holding apparatus for holding a wafer in a wafer processing apparatus.
The wafer is held on the wafer holding device by using an electrostatic force, and the outer peripheral portion of the wafer is formed of an insulating member having the same surface as the wafer processing surface or a surface located above the wafer surface. The surface of the insulating member facing the portion is substantially parallel to the normal direction of the wafer processing surface. According to the present invention, foreign substances can be reduced by eliminating a member that comes into contact with the wafer processing surface. For this purpose, the present invention employs a wafer holding device utilizing electrostatic force. In addition, a structure of a wafer holding device that can limit the use of the elastomer seal, which is a source of foreign matter, as much as possible is employed.
Next, when performing wafer processing by applying RF power to the wafer to generate a bias potential, in order to prevent the occurrence of abnormal discharge, an electrical insulating material such that the RF power application unit does not directly face the reference potential unit. Cut off both. After such treatment, pins for transferring the wafer are provided, and the pins can be electrically connected. The contact between the pins and the wafer removes the charge accumulated on the wafer when the wafer is transferred and instantaneously removes the electrostatic attraction force due to the residual charge, so that the wafer is not pushed up by an excessive force. Also, since the flow path for flowing the coolant for adjusting the wafer temperature is formed by diffusion bonding, brazing, or the like, a structure in which the flow path is formed is completely joined. Even if it is provided, it is not necessary to provide the seal. Therefore, a temperature detector and a wafer presence / absence detector can be easily installed. Further, in order to make the gas flow on the wafer surface uniform, a gas flow equalizing member (referred to as a susceptor) is provided on the outer peripheral portion of the wafer. The surface of the susceptor is located at or above the wafer surface so that the gas flow does not change suddenly on the outer peripheral surface of the wafer. In addition, the surface of the susceptor is made slightly higher than the surface of the wafer so that the surface facing the outer peripheral portion of the wafer is substantially perpendicular to the surface of the wafer, thereby forcing the wafer to move in the horizontal direction and to slide. Further, reaction products and plasma generated during wafer processing may flow between the cover member and the back surface of the wafer facing the back surface of the wafer, and foreign matter may adhere to the back surface of the wafer. This was prevented by reducing the distance between the cover member and the cover member. As described above, since the source of foreign matter adhering to the wafer is eliminated as much as possible, foreign matter is reduced. Further, the gas flow is made uniform and the in-plane uniformity of the wafer processing can be improved. In addition, by devising the structure and manufacturing method of the wafer holding device, the wafer temperature measurement and the wafer presence / absence detector can be easily installed, so that the reliability of the device and the usability can be improved. Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of an embodiment of the present invention. FIG.
1, a wafer 1 is held on a dielectric thin film 3 formed on a metal member 2. Further, under the metal member 2, the insulating member 4 and the base 5 continue, and are supported by the support 6. In the metal member 2, a coolant channel 7 for flowing a coolant for adjusting the temperature of the wafer 1 is formed. In order to supply the coolant to the coolant channel 7, a through hole is formed through the base 5 through the insulating member 4. The cooling medium supply unit 8 is provided. Also,
A wafer transfer pin 9 is inserted into a through hole for the metal member 2, the insulating member 4, and the base 5, and a side wall of the through hole is formed by an insulating tube 10. Wafer delivery pin 9
Is guided by a guide 11 provided around the support 6,
The wafer 1 is transferred by being moved in the axial direction of the column 6 by a vertical mechanism (not shown). Further, inside the support 6, an RF supply shaft 1 is provided via an insulating material 12.
The RF supply shaft 13 is in the form of a pipe, and the inside thereof is a wafer cooling gas supply hole 14. The insulating member 12 penetrates the base 5 and reaches the insulating member 4. The RF supply shaft 13 penetrates through the insulating member 4 and reaches the metal member 2, and the other end (the lower side in the figure) of the RF supply shaft 13, although not shown in FIG. It is connected to each power supply for applying a high voltage for holding and a high frequency bias to the wafer 1. FIG.
Was provided with a wafer detector 15 for checking the presence or absence of a wafer. At this position, a wafer temperature detector can also be installed. A susceptor 16 (cover for the dielectric thin film 3 and the metal member 2) is provided on an outer peripheral portion of the wafer 1 to make gas flow for wafer processing uniform. Also,
The inner peripheral surface of the susceptor 16 faces the back surface of the wafer 1. The susceptor 16 is made of an electrically insulating material such as alumina, and covers the outer peripheral portions of the metal member 2, the insulating member 4, and the base 5. The wafer holding device shown in FIG. 1 is used, for example, in a plasma atmosphere as shown in FIG. FIG. 2 is a schematic diagram of a microwave plasma etching apparatus.
Hereinafter, a case where the wafer holding device of the present invention is applied to an etching apparatus will be described as an example. A vacuum container 17 is provided with a wafer holding device 18, a vacuum pump 19, and an etching gas supply unit 20. Further, microwaves are introduced into the wafer processing chamber 21 through a quartz window 22. Microwaves are generated in a magnetron 23 and passed through a waveguide 24 to a wafer processing chamber 21.
It is led to. Further, a DC power supply 25 for electrostatic attraction and an RF power supply 26 for applying a bias voltage required for etching to the wafer 1 are connected to the wafer holding device 18. The RF supply shaft 13 has a hollow structure,
Gas (Helium etc.) for temperature control is supplied to gas supply hole 2
Introduced from 7. Plasma 28 is placed in wafer processing chamber 21.
Is generated, thereby performing wafer processing. Although not shown in FIG. 2, the vacuum vessel 17 is connected to another vacuum chamber for introducing or carrying out the wafer 1 from the atmosphere via a valve. The wafer 1 transferred to the vacuum chamber 17 using the wafer transfer mechanism is transferred at a transfer position indicated by a two-dot chain line in FIG. Therefore, the wafer holding device 18 is lowered to the transfer position. By raising and lowering the wafer transfer pins 9 at this position, the wafer 1 is transferred and placed on the dielectric thin film surface 3. Note that the coolant for adjusting the temperature of the wafer 1 is as follows.
It is introduced from a coolant supply 8 via a separately provided coolant temperature controller, circulates through a coolant channel 7, and has already adjusted the temperatures of the metal member 2 and the dielectric thin film 3 to predetermined temperatures. Wafer 1
Is mounted on the wafer holding device 18, the wafer detector 1
The laser beam introduced from 5 is reflected on the back side of the wafer,
The reflected light is detected as a signal and the placement of the wafer 1 is confirmed. Although not shown in FIG. 1, the wafer detector 1
The wafer temperature is started to be detected by a wafer temperature detector (fluorescence thermometer) provided in the same manner as in 5. When an etching gas is supplied and microwaves are introduced, discharge is started. In such a state, a DC voltage for electrostatic attraction is supplied from the DC power supply 25, an electric circuit for electrostatic attraction is formed via the plasma 28, and the wafer 1 is attracted to the dielectric thin film 3. . Next, when the helium gas is supplied from the gas supply holes 27, the wafer temperature control via the helium gas proceeds. In this state, the preparation for etching is completed.
Etching is performed by applying a voltage. When the etching process is completed, the application of the RF voltage is stopped. At this time, the plasma 28 is still present. That is, the wafer 1 remains electrostatically attracted. The supply of the etching gas is stopped, and in some cases, a non-etching gas such as argon is introduced instead of the etching gas in order to remove electric charges accumulated during the electrostatic adsorption, and the charge is removed. During this time, the supply of the helium gas is stopped, and the force for pushing up the wafer 1 from the back surface of the wafer 1 is removed. When the charge elimination is completed, the supply of the argon gas is stopped, and the application of the DC voltage for electrostatic adsorption is also stopped. When the etching gas and the charge removing gas are exhausted and a high vacuum is reached, the downward movement of the wafer holding device 18 and the step of unloading the wafer 1 are started. The unloading step is performed in the reverse order of the introduction step, and a new wafer is introduced for the next etching. Thus, etching is performed. Hereinafter, the effects of the present invention will be described in order. The etching gas on the wafer surface and the reaction products (gases) generated by the etching are distributed at a substantially uniform concentration on the surface of the wafer 1, but at the outer peripheral portion of the wafer, the reaction products are generated outside the wafer. There is a possibility that the etching characteristics at the peripheral portion are different from those at the central portion because the boundary of the flow path for the gas flow changes suddenly. Therefore, in the present invention, the susceptor 16 is disposed above the wafer 1 in order to prevent a sudden change in gas flow above the surface of the wafer 1 (or on the same plane). Due to the surface of the susceptor 16, the flow of the etching gas and the reaction product slightly upwards at the outer peripheral portion of the wafer, and the stagnation effect of the etching gas and the reaction product appears. Such a phenomenon will be shown. Therefore, the etching is performed uniformly even in the outer peripheral portion of the wafer. Further, in addition to the above, since the outer peripheral surface of the wafer 1 is housed in the susceptor 16, the electrostatic attraction disappears due to some abnormal situation, and the helium supplied to the back surface of the helium Even if the wafer 1 is moved by the gas pressure, the wafer 1 can be prevented from being largely displaced on the side wall of the susceptor 16, so that it is possible to prevent a situation where the wafer cannot be delivered and the etching chamber must be opened to the atmosphere. is there. At this time, since the surface of the susceptor 16 facing the outer peripheral surface of the wafer is substantially vertical, even if the wafer 1 slides, the surface of the susceptor 16 is tapered.
Unlike the case where the wafer 1 is in the shape of a circle, the wafer 1 does not run on the horizontal surface of the susceptor 16. Next, the gap between the rear surface of the outer peripheral portion of the wafer 1 and the susceptor 16 will be described. FIG. 3 shows an enlarged view of the outer peripheral portion of the wafer. On the wafer processing surface side, plasma 28 is generated, and etching gas and reaction products fly around. Therefore, if the gap between the back surface of the wafer 1 and the susceptor 16 is wide, they enter the gap and accumulate on the back surface of the waste cloth. This is not preferable because it becomes foreign matter on the back surface of the wafer and may lower the yield. Therefore, if the gap between them is made as small as possible, entry of the etching gas and reaction products can be reduced, and foreign matter on the back surface of the wafer can be reduced. According to the results of another test, the above effect was remarkable when the gap was set to 0.3 mm or less. The above-described etching process is performed by applying an RF voltage to the wafer 1. At this time, R
An abnormal discharge may occur between the metal member 2 to which the F voltage is applied and the base 5. When this abnormal discharge occurs, the RF voltage is not normally applied to the wafer 1, and the etching itself becomes abnormal. This can be generally applied to a wafer processing apparatus that generates plasma using an RF voltage, not limited to etching. In order to prevent this, in the wafer holding device of the present invention, the insulating tube 10 is inserted so that the base 5 at a different potential from the RF application unit can be spatially cut off. Thereby, abnormal discharge can be prevented. The delivery of the wafer 1 will be described. The wafer 1 is electrostatically attracted. At this time, electric charges are accumulated on the wafer 1. This electric charge has a capability of adsorbing the wafer 1 to the dielectric thin film 3, and the wafer 1 is electrostatically adsorbed even when the switch of the DC power supply 25 for electrostatic adsorption is turned off. Therefore, the wafer 1 must be transported until the accumulated charges disappear. In addition, there is a problem that it is necessary to determine the presence or absence of disappearance. Therefore, as shown in FIG. 4, the wafer transfer pins 9 are made of a slightly conductive material such as silicon carbide. By doing so, the accumulated charge flows to the ground line through the wafer transfer pin 9 and is quickly eliminated. As a result, highly reliable wafer transfer can be performed without a wafer transfer accident. Note that the ground circuit through the wafer transfer pin 9 can be cut off during the generation of plasma, and since the ground line and the RF application unit are close to each other,
It may be adopted when abnormal discharge occurs. The transfer of the wafer 1 is performed by raising and lowering the wafer transfer pins 9. However, if the wafer 1 is transferred while being vibrated, an abnormality may occur. No.
In the present invention, the guide 11 is provided on the support 6 in order to ensure the guide. As a result, the wafer transfer pins 9 do not become abnormally long due to the vertical mechanism, and a highly reliable wafer transfer becomes possible. As described above, the elements of the highly reliable wafer holding device have been clarified. Next, the transfer position of the wafer 1 and the wafer processing position (corresponding to the wafer position shown in FIG. 2) are described. The problem solving method for different cases will be described. FIG. 5 shows the overall configuration of the wafer holding device. The upper part is almost the same as FIG. 1 in that the insulating member 4 covers the outer peripheral side surface of the metal member 2 to which RF is applied. By doing so, the creepage distance between the RF applying unit and the grounding unit is increased, and the effect of preventing abnormal discharge is further improved. In order to raise and lower the space between the wafer transfer position and the wafer processing apparatus, the present invention uses the support 6 of the wafer holding apparatus.
The bellows 30 is provided between the bellows 30 and the flange 29. The bellows 30 also serves as a vacuum seal for the atmosphere and the wafer processing chamber, and the bellows 30 expands and contracts by a guide of a support 6 provided on the atmosphere side and a vertical mechanism (not shown in FIG. 5). In the present invention, the bellows 30 is provided between the column 6 and the flange 29 so that the diameter of the bellows 30 is minimized. If the diameter of the bellows 30 is small, the force applied to the wafer transfer mechanism can be small.
The simplification and high accuracy of the vertical mechanism can be easily achieved. Needless to say, as compared with the case where a sliding portion using an elastomer seal is provided, foreign matter generated by abrasion of the sliding portion is eliminated, and the reliability of the vacuum seal is improved. As described above, the vertical movement of the wafer holding device is performed. However, the exposure of the bellows 30, the other support columns 6, the wafer transfer pins 9, and the like to the plasma is as follows.
It is not preferable in terms of the problem that the etching product adheres to form foreign matters and the plasma resistance of these materials. Therefore,
In the present invention, cylindrical covers 3 that intersect each other
1, 32 were provided on the base 5 and the flange 29. Cover 3
The cover 1 and the cover 32 overlap each other, and have such dimensions that the overlap does not disappear even when the wafer holding device is moved up and down. Both the covers 31 and 32 are maintained at the ground potential, and the members inside the covers are always isolated from the plasma and protected from contamination. As described above, according to the present invention, it is possible to achieve a wafer holding device and a holding method that perform uniform wafer processing with little foreign matter. The application of the present invention is not limited to an etching apparatus, but is widely applied to a wafer processing apparatus and a processing method which need to hold a wafer (object to be processed) by electrostatic attraction. Of course, you can. However, when looking at FIGS. 1 and 5 from the viewpoint of manufacturing the above-described wafer holding device, it is understood that the manufacturing of the metal member 2 is difficult due to the presence of the coolant channel 7.
Of course, by manufacturing the metal member 2 by dividing it into two members and sealing the refrigerant with an elastomer seal, it is possible to configure a member having the same effect. However, in this method, since a seal portion is required, an extra fastening portion or volume is required, or when a hole is formed through the metal member 2 as shown in FIG. Problems such as complexity and complexity, such as necessity, and a decrease in reliability occur. Therefore, in the present invention, a method is adopted in which the metal member 2 is integrated into a single piece at the stage of manufacturing. Examples are shown in FIGS. FIG.
FIG. As shown in FIG.
The flow path is continuous from the refrigerant supply hole 33 to the refrigerant discharge hole 34. It is possible to manufacture the coolant channel 7 by machining if it is open as shown in FIG. If two members as shown in FIG. 8 are manufactured, and they are overlapped and the outer peripheral portion is joined by welding, the same appearance as the metal member 2 in FIG. 1 can be manufactured. However, it is necessary to provide a through hole (for example, a hole into which the insulating tube 10 of FIG. 1 is inserted) in the seal surface 35 shown in FIG. Therefore, if only the outer peripheral portion of the metal member 2 is joined, the present member cannot be completed. In the present invention, in order to solve this problem, one is to use a lost wax method. This example is shown in FIG. First, a member having substantially the same shape as the coolant channel 7 is manufactured using wax. Next, a mold having the same shape as the outer shape of the metal member 2 on the outside is prepared, and a mold for a flow path made of wax is installed inside and cast. Next, remove the wax,
The metal member 2 is completed. Another embodiment of the present invention is shown in FIG. This is because the coolant channel 7 is machined in advance by a metal member 38 (tentatively described as (upper)) and a metal member 39 (this is referred to as (lower)).
Are overlapped with the bonding material 40 being narrowed therebetween.
If the metal member 2 is aluminum or an aluminum alloy, the joining member 40 is made of an aluminum alloy having a low melting point (such as a silicon-containing aluminum alloy). Then, when the pressure is increased while maintaining the pressure in a vacuum and the temperature is raised to about 600 ° C., the joining member 40 having a low melting point melts and reacts with the metal members (upper) 38 and (lower) 39 to mutually react. Joined. If such a diffusion bonding method is used, the sealing surface 35 shown in FIG. 8 is also securely bonded, so that the through-hole 37 can be processed without any special consideration. Diffusion bonding is not limited to one set, and a large number can be simultaneously bonded. Therefore, if the metal members 38 and 39 are manufactured in advance and bonded in a large amount, there is no particular problem in cost. As described above, according to the present invention, the holding of a wafer by electrostatic attraction is performed by applying a weight to the wafer surface in order to prevent a side slip at the time of transferring the wafer and to prevent the back surface of the wafer from being lifted by gas. Therefore, it is possible to reduce the generation of foreign matter in the wafer processing and to expect an effect of improving the yield of the wafer processing. In addition, since the period during which the wafer processing apparatus can be operated before the wafer processing apparatus must be cleaned in order to reduce foreign matters is lengthened, the operation rate of the apparatus is improved. Furthermore, since the outer peripheral portion of the wafer is made substantially flush with the wafer surface in order to make the gas flow on the wafer surface uniform, there is also an effect that wafer processing with excellent in-plane uniformity is performed. Further, in manufacturing the wafer holding device, an elastomer seal required for a refrigerant seal is not required, and thus there is an effect that the manufacturing of the wafer holding device is facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a wafer holding device according to one embodiment of the present invention. FIG. 2 is an explanatory diagram of a wafer processing apparatus using the wafer holding device of the present invention. FIG. 3 is an enlarged view of a wafer outer peripheral portion of the wafer holding device. FIG. 4 is an explanatory view showing a method of removing accumulated charges when a wafer is transferred. FIG. 5 is an explanatory view of another embodiment of the wafer holding device of the present invention. FIG. 6 is an explanatory view of an embodiment of a method of forming a coolant channel of the wafer holding device. FIG. 7 is an explanatory diagram of another embodiment of the present invention. FIG. 8 is an explanatory diagram of a refrigerant flow path. DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Metal member, 3 ... Dielectric thin film, 4 ... Insulating member, 5 ... Base, 6 columns ... 7 ... Refrigerant channel, 8 ... Refrigerant supply unit, 9 ... Wafer transfer pin , 10 ... insulating tube, 11
... Guide, 12 ... Insulating material, 13 ... RF supply shaft, 14 ... Gas supply hole, 15 Wafer detector ..., 16 ... Susceptor, 17
... wafer holding device, 19 ... vacuum pump, 20 ... etching gas supply unit, 21 ... wafer processing chamber, 22 ... quartz window, 2
3 magnetron, 24 waveguide, 25 DC power supply, 2
6 RF power supply, 27 gas supply hole, 28 plasma, 2
9 ... flange, 30 ... bellows, 31 ... cover, 32 ...
Cover, 33: refrigerant supply hole, 34: refrigerant discharge hole, 35:
Seal surface, 36: lost wax, 37: through hole, 38
... metal members (upper), 39 ... metal members (lower), 40 ... joining members.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshifumi Ogawa 794, Higashi-Toyoi, Kazamatsu, Kamamatsu City, Yamaguchi Prefecture Inside Hitachi Kasado Plant (72) Inventor Hiroyuki Nanada 794, Higashi-Toyoi, Kudamatsu City, Yamaguchi Prefecture Hitachi, Ltd. Inside the Kasado Plant (72) Inventor Tsunehiko Tsubone 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture Inside the Kasado Plant Hitachi, Ltd. (56) References JP-A-5-217951 (JP, A) JP-A-6-205 61336 (JP, A) JP-A-58-32410 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/68 H01L 21/3065

Claims (1)

(1) A wafer holding apparatus for holding a wafer in a wafer processing apparatus, comprising: a metal member; a dielectric thin film formed on the metal member; An insulating member provided to cover the outer peripheral side surface of the member, a base, a support and a wafer transfer pin are provided, connected to a power supply for electrostatic attraction and a power supply for applying a high frequency bias, and a wafer transfer position. In the one configured so as to be able to move up and down as a whole via the support between the wafer processing apparatuses, a flange is provided outside the support via a bellows, and a pair of cylindrical covers overlapping each other are provided on the base and the base. The pair of covers are provided on a flange, and the pair of covers are maintained at a ground potential, and have a length such that the overlap does not disappear even when the wafer holding device moves up and down. Wafer holding device.