JP5331519B2 - Electrostatic chuck - Google Patents

Description

  The present invention relates to an electrostatic chuck.

  The electrostatic chuck is mainly used as a mounting table for fixing a workpiece in various processes of manufacturing a semiconductor device. Here, the “work” mainly corresponds to a wafer or a reticle.

  In addition to fixing the wafer, the electrostatic chuck may be used for the purpose of efficiently removing heat generated by the process from the wafer and keeping the temperature of the wafer constant. For example, in order to enhance the cooling effect of the wafer, the electrostatic chuck is disposed on the cooling device. In order to remove heat from the wafer adsorbed on the electrostatic chuck, a backside gas such as helium (He) is allowed to flow on the back surface of the wafer, and the electrostatic chuck is provided with pores for the backside gas to flow. (For example, refer to Patent Document 1).

  When a wafer is placed on an electrostatic chuck and processed by a plasma etching process or the like, the etching rate tends to be different on the wafer surface due to plasma non-uniformity. As a means for solving such a problem, increasing the plasma density has been demanded.

  As the plasma density increases, the heat input to the wafer increases, so it is necessary to reduce the thickness of the electrostatic chuck, reduce the distance between the metal cooling device and the wafer mounting surface, and increase the cooling efficiency. I came. In this case, arcing may occur in the vicinity of the pores for flowing the backside gas. When arcing occurs, problems such as generation of particles, damage to the processed wafer, breakage of the electrostatic chuck, etc. become obvious. I have done it.

JP 2000-315680 A

  An object of the present invention is to provide an electrostatic chuck capable of preventing the occurrence of arcing accompanying the increase in plasma density.

A first aspect of the present invention is an electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck main body disposed on the cooling device and having a workpiece placement surface,
(A) A gas supply hole extending from one main surface of the cooling device to the surface of the other main surface through the cooling device, and a main countersink having a larger diameter than the gas supply hole at the opening of the gas supply hole (B) an arcing prevention member made of an insulating member provided with a gas flow path communicating with the gas supply hole in the center is embedded in the main countersink portion; and (c) a gas is placed on the work mounting surface. The gist of the present invention is an electrostatic chuck provided with pores communicating with gas supply holes through a flow path.

A second aspect of the present invention is an electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck main body disposed on the cooling device and having a workpiece placement surface,
(A) A gas supply hole extending from one main surface of the cooling device to the surface of the other main surface through the cooling device, and a main countersink having a larger diameter than the gas supply hole at the opening of the gas supply hole And (b) a plurality of grooves defined around the cross-sectional view including the center line in the gas flow direction are provided on the surface so as to become a gas flow path when inserted into the main countersink portion. An electrostatic chuck in which the arcing prevention member is embedded in the main countersink part and (c) the work placing surface is provided with a pore communicating with the gas supply hole via the gas flow path .

A third aspect of the present invention is an electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck main body disposed on the cooling device and having a workpiece placement surface,
(A) A gas supply hole extending from one main surface of the cooling device to the surface of the other main surface through the cooling device, and a main countersink having a larger diameter than the gas supply hole at the opening of the gas supply hole (B) the electrostatic chuck main body side main surface is provided with a cross-shaped counter-sinking part composed of two grooves intersecting at the center in the radial direction, and when inserted into the main countersink part, the gas flow path An arcing prevention member having a plurality of planar cutouts perpendicular to the longitudinal direction of each groove of the cross-shaped counter-sink portion is embedded in the main countersink portion so as to form a cylindrical side surface. (C) The gist of the electrostatic chuck is that the work mounting surface is provided with pores communicating with the gas supply holes via the gas flow path.

  ADVANTAGE OF THE INVENTION According to this invention, the electrostatic chuck which can prevent generation | occurrence | production of the arcing accompanying the high density of plasma density is provided.

(A) shows the cross section of the electrostatic chuck according to the embodiment, (b) shows a view of the cooling device side of the bonding interface between the electrostatic chuck main body and the cooling device of the electrostatic chuck according to the embodiment from above, (C) shows the perspective view of an arcing prevention member. (A) shows the cross section of the electrostatic chuck concerning the modification 1 of embodiment, (b) is the cooling device side of the joining interface of the electrostatic chuck main body and cooling device of the electrostatic chuck concerning the modification 1 of embodiment. The figure which looked at from the upper part is shown, (c) shows the perspective view of an arcing prevention member. (A) shows the cross section of the electrostatic chuck concerning the modification 2 of embodiment, (b) is the cooling device side of the joining interface of the electrostatic chuck main body and cooling device of the electrostatic chuck concerning the modification 2 of embodiment. The figure which looked at from the upper part is shown, (c) shows the perspective view of an arcing prevention member. (A) shows the cross section of the electrostatic chuck concerning the modification 2 of embodiment, (b) is the cooling device side of the joining interface of the electrostatic chuck main body and cooling device of the electrostatic chuck concerning the modification 2 of embodiment. The figure which looked at from the upper part is shown, (c) shows the perspective view of an arcing prevention member. (A) shows the cross section of the electrostatic chuck concerning the modification 3 of embodiment, (b) is the cooling device side of the joining interface of the electrostatic chuck main body and cooling device of the electrostatic chuck concerning the modification 3 of embodiment. The figure which looked at from the upper part is shown, (c) shows the perspective view of an arcing prevention member. (A) shows the cross section of the electrostatic chuck concerning a comparative example, (b) shows the figure which looked at the cooling device side of the joint interface of the electrostatic chuck main body and cooling device of the electrostatic chuck concerning a comparative example from the upper part. Sectional drawing of the conventional electrostatic chuck is shown.

  Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited to the following embodiments. Components having the same function or similar functions in the figures are given the same or similar reference numerals and description thereof is omitted. A description will be given using a wafer as a workpiece.

(Electrostatic chuck)
An electrostatic chuck 10 according to the embodiment shown in FIG. 1A is a static device used in a semiconductor manufacturing apparatus including a cooling device 1 and an electrostatic chuck body 2 that is disposed on the cooling device 1 and has a workpiece placement surface. The electric chuck 10 includes (a) a gas supply hole 1a extending through the cooling device 1 so as to extend from one main surface of the cooling device to the surface of the other main surface, and gas is supplied to the opening of the gas supply hole 1a. A main countersink portion 1b having a diameter larger than that of the supply hole 1a is provided, and (b) an arcing prevention member 3 made of an insulating member provided with a gas flow path 3a communicating with the gas supply hole is embedded in the main countersink portion 1b. (C) The work placement surface is provided with a pore 2a1 communicating with the gas supply hole 1a through the gas flow path 3a. Although not shown for the purpose of facilitating understanding of the invention, the electrostatic chuck main body 2 and the cooling device 1 are joined together by a joining sheet disposed between the electrostatic chuck main body 2 and the cooling device 1. ing. The number of pores is not particularly limited to three.

  The arcing prevention member 3 includes an inner wall 3b having a tapered cross section whose inner diameter extends concentrically from the cooling device 1 side toward the electrostatic chuck body 2 side in a cylindrical inner gas flow path. The diameter of the arcing prevention member 3 is preferably at least twice the thickness of the electrostatic chuck body 2 from the viewpoint of preventing arcing, and from the viewpoint of increasing the plasma density and cooling the workpiece, 4 times or less of thickness is preferable. The minimum inner diameter of the arcing prevention member 3 is equal to or less than the inner diameter of the gas supply hole 1a.

  The thickness between the workpiece mounting surface of the electrostatic chuck main body 2 and the contact surface between the cooling device is preferably 3 mm or less, and more preferably 1.5 mm or less from the viewpoint of enhancing the cooling effect of the workpiece. The plurality of pores 2a1, 2a2, 2a3 provided in the electrostatic chuck body 2 preferably have an inner diameter of 150 μm or less. The material of the electrostatic chuck body 2 is not particularly limited, but from the viewpoint of improving heat conduction and rich corrosion resistance against reactive gases, aluminum nitride ceramics, composite materials including aluminum nitride, alumina ceramics, and alumina are used. A composite material including the composite ceramic of alumina and aluminum nitride is preferable. Further, silicon carbide, yttrium oxide, or a composite material thereof may be used. Since the material of the internal electrode is not particularly limited, it may be a conductive ceramic or metal, but a refractory metal is preferable, and molybdenum, tungsten, or an alloy of molybdenum and tungsten is particularly preferable.

  The material of the arcing prevention member 3 is not particularly limited as long as the insulating property is ensured, but a heat-resistant fluororesin such as polytetrafluoroethylene (for example, Teflon (registered trademark)) or a high melting point insulating property such as alumina. Ceramics may be mentioned. From the viewpoint of long-term use, it is more preferable to use a high-melting point insulating ceramic such as alumina or aluminum nitride having a high thermal conductivity from the viewpoint of cooling as the material of the arcing prevention member is less likely to change in shape.

  The cooling device 1 has a configuration in which a flow path of cooling water is formed inside and the surface of the flow path is covered with an aluminum plate. The maximum diameter of the cooling device is preferably about the same as the maximum diameter of the electrostatic chuck body 2. The thickness of the cooling device 1 is not particularly limited. For example, when the maximum diameter of the cooling device 1 is about 300 mm, the thickness of the cooling device 1 is preferably about 30 to 40 mm. The material of the cooling device 1 is not particularly limited as long as it has good thermal conductivity, but aluminum is preferably used.

  Although various things can be used as a joining sheet without a restriction | limiting in particular, For example, an acrylic resin, a silicone resin, and a modified polyimide resin can be used. In addition, an adhesive may be used instead of the bonding sheet, but it is preferable to use an adhesive sheet with good workability in consideration of the adhesive flowing and protruding.

  The effect of the electrostatic chuck 10 according to the embodiment will be described in comparison with the electrostatic chuck 110 shown in FIG.

  As shown in FIG. 7, when the distance between the cooling device 101 and the electrostatic chuck main body 102 is long, the cooling efficiency of the wafer is low, and the plasma density cannot be increased unless a high voltage is applied. I couldn't meet it.

  Therefore, the present inventors have conceived to reduce the thickness of the electrostatic chuck body 2 as shown in FIG. 1 in order to improve the plasma density and increase the cooling efficiency of the wafer. However, the reason is not clear, but when the plasma is generated because the distance between the cooling device 1 that also serves as an RF electrode and the wafer mounting surface is shortened, arcing or There was a problem that arc marks, which seem to be caused by the occurrence of glow discharge, adhere to the workpiece. Arcing not only damages the cooling device 1, but also causes particles and contamination, and causes damage to the back surface (mounting surface) of the wafer to be mounted.

  In this case, since the distance between the cooling device 101 and the electrostatic chuck main body 102 is long and the space of the gas supply hole 101a is wide in the electrostatic chuck of FIG. 7, an arc is generated by arranging ceramic pieces in the space. Can be prevented. However, if the distance between the cooling device 1 and the wafer mounting surface is short as shown in FIG. 1A, a space for placing the ceramic pieces cannot be secured, and a new arcing prevention method has been demanded.

  As a result of sincerity studies conducted by the present inventors, it has become possible to improve the plasma density and increase the cooling efficiency of the wafer by improving the problem relating to the arc mark according to the above-described embodiment.

  According to the embodiment, by using the arcing prevention member 3, arcing does not occur in the gas supply hole 1a, and higher density plasma can be generated. As a result, for example, in the plasma etching process, the effect of increasing the wafer processing speed can be obtained.

(Electrostatic chuck manufacturing method)
A method for manufacturing the electrostatic chuck 10 will be described in the case where the electrostatic chuck body 2 is made of aluminum nitride.

(A) First, an aluminum nitride powder is formed into a predetermined shape to form a formed body. Thereafter, an internal electrode made of molybdenum is disposed on the formed body. Further, the disk is filled with aluminum nitride powder and molded again to obtain a disk-shaped molded body in which internal electrodes are embedded. The electrostatic chuck 10 is supplied with a DC voltage for attracting the wafer to the electrostatic electrode embedded in the electrostatic chuck body 2 and RF power for generating plasma.

(B) Next, the molded body is sintered in a nitrogen atmosphere to produce the electrostatic chuck body 2 in which the internal electrodes are embedded. A terminal that is electrically connected to the internal electrode is formed to be connectable. The pores 2a1, 2a2, and 2a3 extending from the wafer mounting surface to the cooling device contact surface are provided using a laser processing method or an etching processing method. Although not shown, the electrostatic chuck body 2 may be provided with a plurality of pores in the same manner as the pores 2a1, 2a2, and 2a3.

(C) The cooling device 1 is manufactured, and the cooling device 1 is provided with a through-hole serving as the backside gas supply hole 1a. The arrangement interval and the diameter of the supply holes 1a are not particularly limited. For example, when the diameter of the cooling device 1 is 300 mm, 23 through-holes 1a having a diameter of 1 mm are formed at substantially equal intervals on the circumference 17 mm from the outer peripheral end. It is preferable to provide it. A main countersink portion 1b is provided on the surface of the joint surface with the electrostatic chuck main body 2 serving as an opening of the gas supply hole so that the arcing prevention member 3 can be fitted. When the diameter of the gas supply hole 1a is 1 mm, the size of the countersink is preferably 2.5 mm in diameter and 1.3 mm in depth.

(D) Next, an arcing prevention member 3 as shown in FIGS. The arcing prevention member 3 is fitted into the main countersink part 1 b of the cooling device 1.

(E) Thereafter, the electrostatic chuck main body 2 and the cooling device 1 are joined via a joining sheet.

  Thus, the electrostatic chuck 10 is manufactured.

(Modification of the embodiment)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. The following modifications are mentioned as a modification of embodiment. The arcing prevention member that is a different part will be mainly described.

(Modification 1)
The arcing prevention member 13 shown in FIGS. 2 (a) to 2 (c) is provided with a secondary countersink portion 13 b having a smaller diameter than the outer diameter of the arcing prevention member 13 on the main surface on the electrostatic chuck body 2 side. An insulating member having a plurality of through holes 13a1, 13a2, and 13a3 having a diameter smaller than the inner diameter of the gas supply hole 1a connected from the bottom surface of the portion 13b to the main surface on the cooling device 1 side is provided. It is preferable that the arrangement of the plurality of through holes and the arrangement of the pores of the electrostatic chuck main pair 2 do not overlap each other when viewed from the vertical upper surface of the electrostatic chuck. Although the number of through holes is three in the figure, it may be three or more.

  According to the first modification, it is difficult to generate plasma in the gas supply hole 1a by reducing the space through which the backside gas flows. Although the reason is not clear, the joint between the electrostatic chuck main body 2 and the cooling device 1 is sealed with the arcing prevention member 3, and the creeping distance from the holes 2a1, 2a2, 2a3 of the electrostatic chuck main body 2 to the cooling device 1 is increased. It seems that it grows.

(Modification 2)
The arcing prevention member 23 shown in FIGS. 3A to 3C is provided with a secondary countersink portion 23b having a smaller diameter than the outer diameter of the arcing prevention member 23 on the main surface on the electrostatic chuck body 2 side. A plurality of grooves 23a1 and 23a2 are provided on the surface of the anti-arcing member defined around the cross-sectional view including the center line in the gas flow direction of the anti-arcing member 3 so as to become a gas flow path when inserted into the portion 1b. It has been. The arcing prevention member 33 shown in FIGS. 4A to 4C increases the number of the grooves 23a1 and 23a2 in FIGS. 3B and 3C, and the grooves 33a1 and 33c1 as shown in FIGS. This is an example in the case of 33a2, 33a3, 33a4. According to the second modification, arcing can be prevented for the same reason as the first modification.

(Modification 3)
5A to 5C show the arcing prevention member 43. FIG. As shown in FIG. 5 (c), the arcing prevention member 43 has a cross-shaped sub-assembly made up of _two grooves 43b ₁ and 43b ₂ that intersect the main surface of the electrostatic chuck body 2 at the center in the radial direction of the arcing prevention member 43. A counterbore 43b is provided. As shown in FIG. 5 (a), a cylindrical side surface 43a (as shown in FIG. 5 (b) is formed so as to form the gas flow path 1c when the arcing prevention member 43 is inserted into the main countersink portion 1b. 43a ₁ , 43a ₂ , 43a ₃ , 43a ₄ )), a plurality of planar cutouts 43c ₁ , 43c ₂ , 43c perpendicular to the longitudinal direction of the grooves 43b ₁ , 43b ₂ of the cross-shaped countersink part 43b ₃ and 43c ₄ . The diameter of the arcing prevention member 43 is preferably smaller than the diameter of the main countersink portion 1b as shown in FIG. The backside gas flows through a narrow space between the inner walls of 43a ₁ , 43a ₂ , 43a ₃ , 43a ₄ and the main countersink portion 1b, so that plasma is less likely to be generated in the gas supply hole 1a and effectively prevents arcing. Because it can. If a space through which the backside gas flows is formed between the notches 43c ₁ , 43c ₂ , 43c ₃ , 43c ₄ and the inner wall of the main countersink portion 1b, the diameter of the arcing prevention member 43 is set to the main seat. Although it is good also as substantially the same as the diameter of the feeding part 1b, in order to prevent arcing effectively, it is preferable to make it smaller than the diameter of the main seat feeding part 1b.

  According to the arcing prevention member 43 of FIG. 5, the arcing prevention member 43 is easier to process than the arcing prevention member 3 according to the embodiment and the arcing prevention members 13, 23, and 33 according to the modified example. The same arcing prevention effect as that of the member 3 and the arcing prevention members 13, 23, 33 according to the modified example is obtained. This is advantageous when it is necessary to produce an arcing prevention member using a member that is difficult to process. This is because not only arcing can be effectively prevented but also the flow rate of the flowing gas can be increased by flowing the gas between the side surface 43a and the gas supply hole 1a. A higher gas flow rate is more advantageous because it can be changed in a shorter time when the backside pressure is changed.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

(Manufacture of electrostatic chuck)
(Production Example 1)
An electrostatic chuck according to Production Example 1 was produced under the following conditions in accordance with the production method described above.

(A) An electrostatic chuck main body 2 made of alumina having a diameter of 300 mm and a thickness of 1.1 mm with bipolar electrodes embedded therein was produced. The CO ₂ laser (wavelength 10.6 μm) was irradiated from the cooling device 1 side to provide seven pores 2a1, 2a2, and 2a3 having a diameter of 1 mm. Although not shown, four pores are provided in addition to the pores 2a1, 2a2, and 2a3.

(B) The cooling device 1 made of aluminum was manufactured by setting the diameter of the cooling device 1 to 300 mm, the thickness of the cooling device 1 to 34 mm, and providing 23 through holes having a diameter of 1 mm on the circumference of 17 mm from the outer periphery.

(C) A main countersink portion 1b having a diameter of 2.5 mm and a depth of 1.3 mm for fitting the arcing prevention member 3 on the joint surface side of the through hole with the electrostatic chuck body 2 was provided by an end mill.

(D) An arcing prevention member 3 made of polytetrafluoroethylene having the shape shown in FIGS. In the column of this example, the registered trade name “Teflon (registered trademark)” was used as polytetrafluoroethylene.

(E) After the arcing preventing member 3 is fitted into the main countersink portion 1b of the cooling device 1, the cooling device 1 and the electrostatic chuck body 2 are joined through an acrylic joining sheet to obtain the electrostatic chuck 10. It was.

(Production Examples 2, 3, and 4)
An arcing prevention member made of polytetrafluoroethylene having the shapes of FIGS. 2 (a) to (c), FIGS. 3 (a) to (c), and FIGS. 4 (a) to (c) instead of the arcing prevention member 3 Electrostatic chucks 11, 12, and 13 were manufactured in the same manner as in Production Example 1 except that 13, 23, and 33 were used.

(Production Examples 5, 6, 7, 8)
In place of the arcing prevention member 3, the shapes of FIGS. 1 (a) to (c), FIGS. 2 (a) to (c), FIGS. 3 (a) to (c), and FIGS. 4 (a) to (c) are used. The electrostatic chuck 10 was manufactured in the same manner as in Production Example 1 except that the arcing prevention members 13, 23, 33 made of 99% alumina provided were used.

(Production comparison example)
A manufacturing comparative example according to the manufacturing method according to the above-described embodiment except that the arcing prevention member is not used and the shape of the cooling device 1 is the cooling device 201 shown in FIGS. Such an electrostatic chuck 210 was manufactured.

(Evaluation of anti-arcing effect)
(Examples 1 to 4 and Comparative Example 1)
The anti-arcing effect was evaluated under the conditions shown in Table 1 for the electrostatic chucks shown in FIGS.

  Each of the electrostatic chucks shown in FIGS. 1 to 4 and 6 was placed in an evaluation vacuum chamber. Thereafter, a wafer made of silicon was placed on the electrostatic chuck 10, and a DC voltage was applied to the electrostatic electrode of the electrostatic chuck to attract the wafer. The applied suction voltage was + V250 / −V250.

  Next, after evacuating the chamber and the gas supply line to 0.1 Torr (13.3 Pa), a mixed gas of argon (Ar) and helium (He) is supplied into the chamber, and the pressure in the chamber is set to 1 Torr (133 Pa). ). A gas (He) whose pressure was controlled from the outside of the chamber was supplied to the gas supply hole 1a of the electrostatic chuck and used as a backside gas for the wafer. The backside gas (He) pressure was 10 Torr (1330 Pa) as shown in Table 1. Here, the wafer backside gas is a gas in a space formed between the adsorbed wafer and the electrostatic chuck surface.

  Thereafter, a high frequency voltage of 13.56 MHz is applied between the upper and lower parallel plate electrodes (ie, the upper electrode plate provided in the chamber and the cooling device 1), and the space between the electrostatic chuck 10 and the upper electrode plate (ie, the upper electrode plate). Plasma was generated on the wafer). The application was stopped after 1 minute, left for 30 seconds, and then a cycle of generating plasma for 1 minute was repeated 10 cycles.

Thereafter, the electrostatic voltage was grounded, the voltage was reduced to 0 volts, the wafer was detached, and the presence or absence of arcing was visually confirmed. Those having traces on the back side of the wafer were evaluated as “Yes”, and those having no trace were evaluated as “None”. The results obtained are summarized in Table 1.

(Examples 5 to 8, Comparative Example 2)
As shown in Table 2, the anti-arcing effect was evaluated in the same manner as in Example 1 except that the backside gas pressure was 1 Torr (133 Pa). The results obtained are summarized in Table 2.

(Examples 9 to 13, Comparative Example 3)
As shown in Table 3, the anti-arcing effect was evaluated in the same manner as in Example 1 except that 99% alumina was used as the material for the anti-arcing member. The gas flow rate was measured according to the following criteria. The results obtained are summarized in Table 3.

(Measurement method of gas flow rate)
A mass flow meter was installed in the middle of the piping connected to the gas supply source and the gas supply hole of the electrostatic chuck. Then, the inside of the chamber was evacuated (= approximately 0 Torr (Pa)), and the flow rate of gas flowing through the electrostatic chuck was measured with a mass flow meter without placing the wafer. In the table, the backside gas pressure of 10 Torr (1330 Pa) indicates that the pressure of the gas supply source is 10 Torr (1330 Pa). When the wafer is adsorbed, the backside pressure and the pressure of the gas supply source are the same. . If the wafer is not adsorbed, gas is released in a vacuum of 0 Torr (Pa) and there is no backside pressure. “SCCM” in Table 3 is an abbreviation for standard cc (cm ³ ) / min, and the flow rate when converted per unit time at a constant temperature (25 ° C.) under 1 atm (atmospheric pressure 1,013 hPa). Show.

  From Table 3, it was found that arcing can be prevented while maintaining a gas flow rate that can withstand implementation. In particular, in Examples 9 and 13, arcing could be prevented while maintaining the same gas flow rate as in the comparative example.

(Examples 14 to 18, Comparative Example 4)
As shown in Table 4, the arcing prevention effect was evaluated in the same manner as in Example 1 except that 99% alumina was used as the material for the arcing prevention member and the backside gas pressure was 1 Torr (133 Pa). did. The obtained results are summarized in Table 4.

  As shown in Tables 1 to 4, it was found that the electrostatic chuck having the arcing prevention member according to the example does not cause arcing until the plasma output is higher than that of the comparative example.

  From the comparison between Table 1 and Table 2, it was found that when the pressure of the backside (He) gas is low, arcing tends to occur at a lower plasma output. The same can be said from the comparison between Table 3 and Table 4. Even when the pressure of the backside gas was low, it was found that the electrostatic chuck having the arcing prevention member according to Examples 1 to 16 functions effectively.

  In addition, when a plasma voltage is applied to the same electrostatic chuck after arcing has occurred once, when an arcing prevention member made of polytetrafluoroethylene is used, arcing tends to occur at a lower plasma output. On the other hand, when an alumina arcing prevention member was used, arcing occurred with the same plasma output. This difference is considered to be caused by the heat resistance of the arcing prevention member. That is, it is considered that the arcing preventing member made of polytetrafluoroethylene changes its shape due to arcing, whereas the shape of alumina hardly changes. Therefore, the material of the arcing prevention member is more preferably a high melting point insulating ceramic such as alumina.

DESCRIPTION OF SYMBOLS 1 ... Cooling device, 1a ... Gas supply hole, 1b ... Main countersink part,
3 ... arcing prevention member, 3a ... gas flow path,
2 ... electrostatic chuck body, 2a1, 2a2, 2a3 ... pore 10, 11, 12, 13 ... electrostatic chuck

Claims (9)

An electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck body disposed on the cooling device and having a workpiece placement surface,
A gas supply hole extending through one of the main surfaces of the cooling device from the main surface to the other main surface, and a main seat having a larger diameter than the gas supply hole at the opening of the gas supply hole A feeding part is provided,
An arcing prevention member made of an insulating member provided with a gas flow path communicating with the gas supply hole is embedded in the main countersink part,
The work placement surface is provided with a pore communicating with the gas supply hole via the gas flow path ,
The electrostatic chuck according to claim 1, wherein the arcing prevention member includes an inner wall having a tapered cross section whose inner diameter expands concentrically from the cooling device side toward the electrostatic chuck body side in the gas flow path . An electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck body disposed on the cooling device and having a workpiece placement surface,
A gas supply hole extending through one of the main surfaces of the cooling device from the main surface to the other main surface, and a main seat having a larger diameter than the gas supply hole at the opening of the gas supply hole A feeding part is provided,
An arcing prevention member made of an insulating member provided with a gas flow path communicating with the gas supply hole is embedded in the main countersink part,
The work placement surface is provided with a pore communicating with the gas supply hole via the gas flow path,
The gas supply connected to the cooling device side main surface from the bottom surface of the counter-sinking part is provided with a sub-sinking part having a smaller diameter than the outer diameter of the arcing-preventing member on the electrostatic chuck main body side of the arcing prevention member the electrostatic chuck than the inner diameter of the hole characterized in that the gas flow path of smaller diameter provided plural. An electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck body disposed on the cooling device and having a workpiece placement surface,
A gas supply hole extending through one of the main surfaces of the cooling device from the main surface to the other main surface, and a main seat having a larger diameter than the gas supply hole at the opening of the gas supply hole A feeding part is provided,
An arcing prevention member provided with a plurality of grooves defined on the surface of a cross-sectional view including a center line in the gas flow direction so as to be a gas flow path when inserted into the main countersink portion, Embedded in the main countersink,
The electrostatic chuck according to claim 1, wherein the work mounting surface is provided with a pore communicating with the gas supply hole via the gas flow path. 4. The electrostatic chuck according to claim 3 , wherein a sub counter-sink portion having a smaller diameter than the outer diameter of the arcing prevention member is provided on the electrostatic chuck main body side of the arcing prevention member. An electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck body disposed on the cooling device and having a workpiece placement surface,
A gas supply hole extending through one of the main surfaces of the cooling device from the main surface to the other main surface, and a main seat having a larger diameter than the gas supply hole at the opening of the gas supply hole A feeding part is provided,
The electrostatic chuck main body side main surface is provided with a cross-shaped counter-sink portion composed of two grooves that intersect at the center in the radial direction, and when inserted into the main counter-sink portion, a gas flow path is formed, An anti-arcing member having a plurality of planar cutouts perpendicular to the longitudinal direction of each groove of the cross-shaped counter-sink portion on a cylindrical side surface is embedded in the main countersink portion,
The electrostatic chuck according to claim 1, wherein the work mounting surface is provided with a pore communicating with the gas supply hole via the gas flow path. The diameter of the arcing preventing member, the electrostatic chuck according to claim 5, wherein the smaller this than the diameter of said main spot facing portion. An electrostatic chuck used in a semiconductor manufacturing apparatus including a cooling device and an electrostatic chuck body disposed on the cooling device and having a workpiece placement surface,
A gas supply hole extending through one of the main surfaces of the cooling device from the main surface to the other main surface, and a main seat having a larger diameter than the gas supply hole at the opening of the gas supply hole A feeding part is provided,
An arcing prevention member made of an insulating member provided with a gas flow path communicating with the gas supply hole is embedded in the main countersink part,
The work placement surface is provided with a pore communicating with the gas supply hole via the gas flow path,
The electrostatic chuck you wherein the diameter of the arcing preventing member is not more than 4 times 2 times the thickness of the electrostatic chuck body. The electrostatic chuck according to any one of claims 1 to 6, wherein the diameter of said arcing preventing member is not more than 4 times 2 times the thickness of the electrostatic chuck body. The electrostatic chuck according to any one of claims 1 to 6, wherein the arcing preventing member, characterized in that it consists of alumina or aluminum nitride.

Images