JP4216279B2 - Insulator and plasma processing apparatus having the same - Google Patents

Description

  The present invention relates to a plasma such as a plasma CVD apparatus or a dry etching apparatus used in manufacturing a semiconductor such as a silicon solar battery or the like, and an insulator that obtains an insulation state between a conductor and an element connected to the conductor. The present invention relates to a processing apparatus.

  Conventionally, when a semiconductor such as a silicon solar cell is manufactured, a plasma CVD apparatus using plasma is known as an apparatus for forming the film, and the substrate surface on which the film has been formed is etched with plasma. A dry etching apparatus is generally known. A plasma CVD apparatus 10 shown in FIG. 8 will be described as a configuration example of a plasma processing apparatus using these plasmas.

A film forming chamber 12 (processing chamber) provided in the plasma CVD apparatus 10 (plasma processing apparatus) shown in the figure is a film forming unit 14 provided with ladder electrodes 13 (electrodes) on both sides at the approximate center of the vacuum chamber 11. A substrate heater 16 is provided on both side surfaces of the film forming unit 14 via a heater cover 15. Then, the substrate K is disposed on the heater cover 15 so as to face the ladder electrode 13, and a film forming process is performed on the substrate.

Further, as shown in FIG. 9, the ladder electrode 13 includes a pair of power feeding rods 13a and a plurality of parallel vertical grids 13b that electrically connect the power feeding rods 13a.
The power feeding rod 13a is provided with a power feeding portion 13c connected to a plurality of high frequency cables 18 (also referred to as RF cables) at a plurality of locations, and high frequency power is fed from the power feeding portion 13c to the power feeding rod 13a. It has become.

  In the film forming chamber 12, a film forming gas that is a processing raw material gas containing a raw material gas made of SiH 4 is sent in a vacuum state in which the vacuum chamber 11 is decompressed, and high frequency power is supplied to the ladder electrode 13. Then, plasma is generated between the ladder electrode 13 and the deposition preventing plate 17, and a film is formed on the substrate K heated by the substrate heater 16.

  In the plasma processing apparatus such as the plasma CVD apparatus 10 configured as described above, the ladder electrode 13 for generating plasma is connected to a high frequency cable 18 that supplies high frequency power and is supported in an insulated state. The film forming chamber 12 is provided. Therefore, an insulator for supporting the ladder electrode 13 in an insulated state is generally used. A configuration in which such an insulator is provided as a ceramic support member has already been disclosed (for example, see Patent Document 1).

  However, a thick film is deposited on the insulator supporting the ladder electrode 13 by repeating the film forming process, or a film having a high conductivity in the film forming process, particularly an n doped with P (phosphorus) in an amorphous silicon film. If a mold film or the like adheres and accumulates, there is a high possibility that the insulation resistance of the insulator will decrease in a short period of time and the ladder electrode 13 will be grounded. Then, depending on the influence of the ground fault, the generation of plasma from the ladder electrode 13 may become abnormal, causing a problem that the film forming process becomes unstable and the film thickness distribution becomes non-uniform.

In order to solve such a problem, there has already been shown an insulator in which the insulator is made into a double-pipe structure to cut a film (see, for example, Patent Document 2).
In addition to the portion that supports the ladder electrode 13, an annular groove is formed in the power feeding portion 13 c that is a connection portion between the ladder electrode 13 and the high-frequency cable 18 that supplies high-frequency power to the ladder electrode 13. A configuration for performing film cutting is shown (see Patent Document 2).
Further, in a gas pipe electrode (gas supply electrode) that functions as an electrode for generating plasma while supplying a film-forming gas, the film of the deposit is cut at the connection portion between the gas pipe electrode and the film-forming gas supply line. A structure of a connecting pipe having a double pipe structure is shown (for example, see Patent Document 3).
JP 2002-246321 A (paragraphs 34-37, FIGS. 9-11) JP 2000-208297 A (paragraphs 16-18, FIG. 4, and 12-15, FIG. 2) JP 2001-120985 (paragraphs 23-25, FIG. 6)

  However, in recent years, large-scale ladder electrodes are often provided for the production of large-area substrates having a side exceeding 1 m, and ceramics or the like that secure this support strength when supporting such ladder electrodes. It is difficult to produce an insulator made of an insulator. That is, the conventional double-pipe structure insulator having a single-piece structure is difficult to manufacture due to this complicated structure, resulting in an increase in manufacturing cost. In addition, the shape and size for obtaining the strength for supporting the ladder electrode that has increased in weight are excessively enlarged due to a complicated shape, and the size of the apparatus with respect to the substrate has been increased.

  The present invention has been made in view of the above circumstances, and while cutting off the ground fault of a conductor including an electrode for generating plasma and the like to ensure a reliable insulation state and obtaining a stable operation, it is small in size. An object of the present invention is to provide an insulator having a strength sufficient for manufacturing a large-area substrate and a plasma processing apparatus including the same.

In order to solve the above problems, the invention described in claim 1 is used in plasma processing apparatus for performing a film on a substrate, it is connected to conductors including an electrode for generating plasma land of the conductor by an insulating It met insulator that to prevent fault, an inner member made of an insulating material which is directly connected to the conductor, are spaced apart so as to cover the outer peripheral portion axial length than the inner member of the inner member a short cylindrical outer member, it is provided with a holding member for holding the positional relationship by contact with these two members together are disposed between the inner member and the outer member, said outer member, said A wall portion of either the outer member or the inner member that is supported only by the inner member via the holding member and is in contact with the holding member is provided with a restraining portion that supports and holds the holding member. When That.

  With this configuration, even when a highly conductive material adheres to and accumulates on the surface of the insulator according to the present invention connected to the conductor, the outer peripheral portion of the inner member is covered by the outer member. As a result, the above deposits do not adhere to the entire surface of the insulator. That is, the film of the deposit is partially cut at the gap between the outer member and the inner member, thereby ensuring an insulating state in which the potential difference is maintained on both sides of the insulator. And since the insulator which has the above film cutting structures is comprised by the combination of each member which has a simplified shape, ensuring of intensity | strength and manufacture are easy.

  When the inner member and the outer member are in contact with each other by the deposits described above, the insulation resistance is lowered. However, the gap between the inner member and the outer member is always maintained uniformly by the holding member. Are not touched by deposits. In addition, since the gap between the two members is defined by the thickness of the holding member, it is easy to guide the separation distance between the two members to a very small size. If the gap size is reduced, the intrusion path of the deposit is further narrowed, and the intrusion of the deposit is suppressed and the film cutting effect is further enhanced.

Further, the holding member is disposed in a state of being caught by the restraining portion, and the position of the holding member remains in a fixed position without being affected by the installation direction of the insulator, deformation due to heat input, vibration, or the like. As a result, the positional relationship between the inner member and the outer member is always kept constant, and there is no problem such that the inner member and the outer member are in contact with each other unexpectedly.
Note that the constraining portion may be, for example, a recess into which the holding member is fitted, or may be a convex portion that supports the holding member, and a wall surface on which such a constraining portion is formed contacts the holding member. Either the inner periphery of the outer member, the outer periphery of the inner member, or both may be used.

  Note that the connection between the conductor and the inner member includes a simple connection method in which the conductor is fitted with a slight gap. Further, the material of the outer member and the holding member is not necessarily an insulator, but it is necessary to select the material according to the installation environment. Further, it is desirable that the holding member is positioned in the vicinity of the central portion of the entire length in the axial direction of the outer member so that the attached matter does not reach the holding member. This also fixes the outer member to the inner member with a good balance.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the inner member is provided with a flow path for conducting fluid therein.

According to such a configuration, in order to supply the fluid to the conductor, the element to be insulated connected to the conductor is a film in which the inner member and the outer member are spaced apart by the holding member. The insulator having the cut structure is insulated from the conductor in any environment.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the holding member is a helical structure surrounding the outer peripheral portion of the inner member.

With such a configuration, the inner member and the outer member are fixed via a spiral structure such as a spring that is spirally wound around the outer periphery of the inner member. Suppression is suppressed. Further, according to the helical structure the restraining portion according to claim 1 is arranged, so that the mutual member is fixed positioning of the outer member and the inner member is more accurately defined.

  The invention described in claim 4 is the invention described in claim 1 or 2, wherein the holding member is a leaf spring.

With such a configuration, the outer member is fixed at a fixed position of the inner member by the elastic force of the leaf spring, so that the rattling is more reliably removed and a firmly fixed insulator is configured. . Further, even when there is a difference in deformation due to heat input between the inner member and the outer member, the plate spring can absorb this deformation difference.
Further, according to placing the leaf spring restraining portion according to claim 1, so that the mutual member is fixed positioning of the outer member and the inner member is more accurately defined.

According to a fifth aspect of the present invention, there is provided a plasma processing apparatus having a gas supply electrode connected to a high frequency cable to generate plasma in a processing chamber and supplying a film forming gas to a substrate installed in the processing chamber. The gas supply electrode and the film forming gas supply line are connected to each other through the insulator according to any one of claims 1 to 4 .

  With such a plasma processing apparatus, the gas supply electrode charged by the high-frequency power supplied from the high-frequency cable performs the film-forming process on the substrate by transmitting the film-forming gas while generating plasma. However, at this time, the film forming process is performed while the insulating state between the film forming gas supply line and the gas supply electrode is reliably maintained by the film cutting structure of the insulator. Therefore, a ground fault in the gas supply electrode is avoided and the generation of plasma is made uniform.

The insulator according to the first aspect of the present invention includes an inner member that is an insulator that is directly connected to a conductor, an outer member that is spaced apart so as to cover the outer periphery of the inner member, and the inner member Between the inner member and the outer member, and the holding member that holds the positional relationship by being in contact with both members. The film cutting effect can be further enhanced by suppressing the intrusion of deposits by making it possible to reduce the amount. As a result, it is possible to reliably obtain an insulating state by the insulator and to lead an accurate operation of the conductor.
In addition, since each element constituting the insulator is simply formed individually and is configured to be easily combined by attaching a holding member, an insulator that obtains a high film cutting effect and performs insulation has high rigidity, It can be realized at low cost.
Further, the film cutting portion can be formed in a space-saving manner without waste in the axial direction, and a small insulator that is short in the axial direction can be obtained.

In addition, since any one of the wall surfaces of the outer member and the inner member that are in contact with the holding member is provided with a restraining portion that supports and holds the holding member, external influences such as installation direction, thermal deformation, vibration, etc. Even if it is a case where it receives, it becomes more reliable to fix the positional relationship of an outer member and an inner member to a fixed position. Therefore, the reliability of the film cutting effect on the deposit can be improved. In addition, since the fixed state is good, there is no restriction on the installation environment in which the insulator is installed, and the degree of freedom of installation is increased, so that versatility can be improved.
In addition, the connection distance can be shortened to reduce the space required for the connection, and the degree of freedom of design in the device provided with the insulator and the miniaturization of the device can be realized.

According to the insulator according to the second aspect of the present invention, since the flow path for conducting the fluid is provided inside the inner member, the fluid supply source element to be insulated and the conductor to which the fluid is supplied The fluid can be supplied in a state in which they are reliably insulated from each other. This makes it possible to guide the operation of the conductor and the element to be insulated connected thereto to a normal state.

  According to the insulator according to the invention described in claim 3, since the insulator is provided with a spiral structure surrounding the outer peripheral portion of the inner member as the holding member in the previous invention, the inner member and the outer member can be provided with a simple configuration. Can be fixed at a fixed position to suppress rattling of each other. In addition, the insulator can be obtained at a reduced cost by simplifying the configuration.

According to the insulator according to the invention of claim 4, since the holding member in the previous invention is a leaf spring, the outer member and the inner member can be firmly fixed in place by the elastic force of the leaf spring. This can increase the rigidity of the insulator made into a composite. Moreover, even when there is a difference in thermal expansion between the outer member and the inner member, this difference can be absorbed by the leaf spring, and a highly reliable insulator that avoids shape change or breakage is realized. Can do.
In addition, it is easy to insert the holding member between the outer member and the inner member while firmly fixing the outer member and the inner member as described above, and the manufacturing can be facilitated. That is, by contracting the leaf spring with a force superior to the elastic force, it is possible to attach the leaf spring even if the gap between the two insulators is narrow, and the combined state is strengthened by the elastic force acting after the attachment. Can get to. Therefore, it is possible to realize a highly rigid insulator while appropriately and easily forming a film-cutting structure for the deposit.

  According to the plasma processing apparatus of the fifth aspect of the present invention, the gas supply electrode and the film forming gas supply line are connected by the insulator according to any one of the first to fourth aspects. Therefore, even if a film in the film forming process with high conductivity adheres and accumulates on this connection portion, the grounding on the gas supply electrode side is avoided by the film cutting effect of the insulator having a flow path inside, and the fluid is supplied. Can be supplied.

Next, each embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is an exploded perspective view for explaining the structure and configuration of the film forming unit 14.
The film forming unit 14 includes a film forming unit support base 31 placed on a base serving as a base, and each component is supported on the film forming unit support base 31.

A support protrusion 31a is formed in the center of the film forming unit support base 31 in the longitudinal direction, and a temperature control heater / cooler (not shown) is supported on the support protrusion 31a. Yes. The temperature control heater / cooler is surrounded by the top plate 32, the side plate 33 and the end plate 34.
On both sides of the temperature control heater / cooler, an end face plate 34, a deposition preventing plate 17, a ladder electrode 13 and a substrate holding plate 21 are arranged in this order, and the support structure of the ladder electrode 13 will be described below.

The ladder electrode 13, which is a conductor, forms a gas supply integrated gas supply electrode, and a plurality of pipe-shaped vertical grids 13 b are provided between a pair of pipe-shaped power supply rods 13 a arranged vertically. The structure is provided with a gap.
And the upper end part of the ladder electrode 13 is supported by the electrode upper end support insulator 40 (insulator) provided in the exhaust cover 35, as shown to Fig.2 (a).

The electrode upper end support insulator 40 is a cylindrical inner member 41 inserted from above into a hole formed in the exhaust cover 35 and a cylindrical shape that is spaced apart so as to cover the outer periphery of the inner member 41. It has an outer member 42 and a helical structure (holding member) (see reference numerals 43 and 53 in FIG. 3) positioned between them.
A curved recess 44 is formed at the front end of the inner member 41 (the lower end side in the drawing), and the power supply rod 13a above the ladder electrode 13 is directly connected to the recess 44. It comes to be held in contact with.

  A ring member (not shown) having an outer diameter larger than that of the hole of the exhaust cover 35 is attached in the vicinity of the rear end portion (upper end side in the drawing) of the inner member 41, and an electrode including the inner member 41. The upper end support insulator 40 is prevented from falling off the exhaust cover 35.

  Moreover, as shown in FIG.2 (b), the film forming unit support stand 31 shown in FIG. 1 is provided with the electrode lower end support insulator 50 (insulator) arrange | positioned in the vicinity of both sides in this upper surface. In addition to the support of the ladder electrode 13 described above, support is provided on the lower side of the ladder electrode 13.

The electrode lower end support insulator 50 is fitted to a base plate member 55 fixed to the film forming unit support base 31 by screws 61a. As a configuration of the electrode lower end support insulator 50, the electrode lower end support insulator 50 is fitted to the base plate member 55. The inner member 51 made of ceramic, the cylindrical outer member 52 spaced apart so as to cover the outer periphery of the inner member 51, and a helical structure (not shown) located between them ) Is provided.
A concave portion 54 formed in a curved shape is formed at the distal end portion (upper end side in the drawing) of the inner member 51, and the power feeding rod 13 a below the ladder electrode 13 is in direct contact with the concave portion 54. It is supposed to be retained.

  The hole 55a through which the screw 61a for fixing the base plate member 55 to the film forming unit support base 31 passes is a length along the direction orthogonal to the longitudinal direction of the ladder electrode 13 supported by the electrode lower end support insulator 50. It is a hole.

Now, the configuration and structure of the electrode upper end support insulator 40 and the electrode lower end support insulator 50 which form the above-described insulator of the present invention will be described in detail with reference to FIG.
As shown in FIG. 3 (a), the electrode upper end support insulator 40 includes an inner member 41 made of an insulator such as ceramics that is directly fitted and connected to the power supply rod 13a of the ladder electrode 13 that is a conductor. The outer member 42 spaced apart so as to cover the outer peripheral portion of the inner member 41, and disposed between the inner member 41 and the outer member 42 and in contact with both the members 41, 42, both members 41, And a spring-shaped spiral structure 43 (holding member) that holds the positional relationship of 42.

  The configuration and structure of the electrode lower end support insulator 50 shown in FIG. 3B is the same as that of the electrode upper end support insulator 40 shown in FIG. And a helical structure 53 (holding member).

According to the configuration in which each of the supporting insulators 40 and 50 is provided to support the ladder electrode 13, a film such as amorphous silicon having high conductivity adheres to the surface of each of the supporting insulators 40 and 50 in the film forming process using plasma. Even if deposited, since the outer peripheral portions of the inner members 41 and 51 are covered with the outer members 42 and 52, it is possible to avoid the adhesion film from adhering to all the surfaces of the support insulators 40 and 50.
That is, the film is cut in such a way that the adhering film is partially interrupted at the gaps between the outer members 42 and 52 and the inner members 41 and 51, so that the exhaust cover 35 and the ladder electrode 13 that are the mother body and the manufacturing that is the mother body The membrane unit support 31 and the ladder electrode 13 are insulated from each other, and a potential difference of 300 to 500 V on both sides of the support insulators 40 and 50 is maintained.

  The support insulators 40 and 50 having the above-described membrane cutting structure are formed by spirally connecting the single-shaped inner members 41 and 51 having the cylindrical shape to the single-shaped outer members 42 and 52 having the cylindrical shape. Since it is a simple structure combined through a structure, it is possible to easily obtain the strength required for support by limiting to the inner members 41 and 51, and individual manufacturing costs can be suppressed in manufacturing. Assembling is simply performed in the state.

  Further, since the gap S between the inner members 41, 51 and the outer members 42, 52 is always maintained uniformly by the spiral structures 43, 53, it is avoided that these members 40, 50 are in contact with each other by the adhesion film. Since the gap S between the two members is defined by the thickness of the spiral structures 43 and 53, it is possible to easily guide the separation distance between the two members 40 and 50 to a very small size. If the gap S is reduced, the intrusion path of the deposit is further narrowed, and the intrusion of the deposit is suppressed and the film cutting effect is further enhanced.

The materials of the outer members 42 and 52 and the spiral structures 43 and 53 are not necessarily made of an insulator such as ceramics, and SUS304 or Inconel material that does not affect plasma is used. Also good.
Further, the spiral structures 43 and 53 are positioned near the central portion of the entire length of the outer members 42 and 52 in the axial direction (up and down direction on the paper surface) so that the deposits in the film forming process do not reach the spiral structures 43 and 53. I am going to let you. This also fixes the outer members 42 and 52 to the inner members 41 and 51 with good balance.

  According to the support insulators 40 and 50 for supporting the ladder electrode 13 according to the present embodiment described above and the plasma CVD apparatus having the support insulators 40 and 50, both members (41, 42 and 51, 52) having a double tube structure are used. It is possible to narrow the gap S in accordance with the dimensions of the spiral structures 43 and 53 and to increase the depth, thereby preventing intrusion of substances adhering to the film and obtaining a more effective film cutting effect than before. Can do. Accordingly, it is possible to ensure an insulation resistance of 1 MΩ or more, which is generally required in the film forming process, and to stabilize the film forming process and obtain a uniform film thickness distribution. As a result, a high-quality substrate can be obtained.

  Moreover, it becomes possible to guide the strength for supporting the large ladder electrode 13 corresponding to the large substrate with a simplified small shape, and the supporting insulators 40 and 50 satisfying the above requirements and suppressing the cost, A low-cost and compact plasma CVD apparatus having the supporting insulators 40 and 50 can be realized.

In addition, the structure demonstrated below may be sufficient as a modification of this embodiment.
Each of the supporting insulators 40 and 50 shown in FIGS. 4 (a) and 4 (b) has a helical structure 43 and 53 as compared with the structure of the supporting insulators 40 and 50 described above. The difference is that an annular recess D1 is formed on the outer periphery of the inner members 41, 51 to be attached, and an annular recess D2 is formed on the inner periphery of the outer members 42, 52. Each of these recesses D1 and D2 refers to a restraining portion according to the present invention and plays a role of supporting the helical structures 43 and 53.

  The depths of the recesses D1 and D2 are formed to be extremely shallow compared to the diameters of the inner members 41 and 51, and the width dimension corresponding to the vertical direction in the drawing is the height dimension of the spiral structures 43 and 53. Are formed so that they are substantially equivalent.

  As described above, the outer and inner sides of the spiral structures 43 and 53 are supported and held in the respective recesses D1 and D2, so that the positions of the spiral structures 43 and 53 can be changed when starting or stopping. It is held in place without being affected by thermal deformation, deformation or thermal expansion due to heat input, vibration applied to the inner members 41 and 51 and the outer members 42 and 52, and further, the installation direction of the support insulators 40 and 50, etc. .

  As a result, the positional relationship between the inner members 41 and 51 and the outer members 42 and 52 is always kept constant, the stability of the shape of each support lever 40 and 50 is maintained, and both members (41 and 42, and 51 and 52). ) It is possible to avoid the problem of contact between each other. Further, even if there is a limit to the thickness required for thinning the spiral structures 43 and 53 due to the formation of the recesses D1 and D2, this thickness can be offset by the depth of the recesses D1 and D2. The gap S between the inner members 41 and 51 and the outer members 42 and 52 can be further reduced. Therefore, it is possible to further enhance the film cutting effect of the attached film and maintain the insulating state.

Although the case where the recesses D1 and D2 are provided as the restraining portions has been described above, the present invention is not limited to this, and each member 41, which is caught in the gap portion of the spiral structures 43, 53, is not limited thereto. Similar operations and effects can be obtained even if the convex portions are formed on the wall surfaces of 42, 51, 52, or the convex portions sandwich the spiral structures 43, 53 in the height direction.
Moreover, although the case where the recessed part was formed in each of the inner side members 41 and 51 and the outer side members 42 and 52 was demonstrated, even if it forms in either one, the helical structure bodies 43 and 53 are hold | maintained in a fixed position. It is possible.

  Further, as a second modified example, the configuration of the support insulators 40 and 50 as shown in FIGS. 5A and 5B may be adopted. Reference numerals 43 ′ and 53 ′ shown in FIG. 5 are leaf springs (holding members) provided in place of the spiral structures 43 and 53 described above, and inner members are formed by these leaf springs 43 ′ and 53 ′. Outer members 42 and 52 are fixed to 41 and 51.

When such leaf springs 43 ′ and 53 ′ are used, the outer members 42 and 52 are fixed to the fixed positions of the inner members 41 and 51 by this elastic force, and the rattling of each other occurs. The highly rigid support insulators 40 and 50 that are more reliably removed and firmly fixed can be realized.
And even if there is a difference in deformation due to heat input between the inner members 41, 51 and the outer members 42, 52, that is, even when there is a difference in thermal expansion, the leaf springs 43 ', 53' absorb this deformation difference. Is possible and will not be damaged.

  Of course, according to the configuration in which the restraining portions such as the recesses D1 and D2 described above are appropriately provided in the members 41, 42, 51 and 52 to support the leaf springs 43 ′ and 53 ′, the outer members 42 and 52 and the inner members The positioning with respect to 41 and 51 is more accurately defined and fixed to each other.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. Note that the ladder electrode 13 shown in the present embodiment forms a gas supply electrode integrated with the gas blowing provided in the plasma CVD apparatus 10 described in the related art and the first embodiment, and is related thereto. The same reference numerals are given to the structure and configuration, and a part of the description will be omitted, and different points will be described in detail.

As shown in FIG. 6A, the ladder electrode 13 disposed inside the deposition preventing plate 17 is provided with a plurality of holes 13d for supplying a film-forming gas (fluid) containing a source gas into the film-forming chamber. The ladder electrode 13 is formed by combining conductor pipes for the convenience of charging the high frequency power while sending the film forming gas.
The ladder electrode 13 is connected to a gas supply pipe 100 that supplies a film-forming gas through a connecting insulator 60 (insulator) having a double-pipe structure. Needless to say, the inside of the connecting insulator 60 In detail, the flow path F for making the gas for film forming conduct | electrically_connecting is provided in the inside of the inner member 61 which is one element which comprises this.

  The connecting insulator 60 will be described in detail. The connecting insulator 60 includes an inner member 61 directly connected to the gas supply pipe 100 at one end and directly connected to the ladder electrode 13 at the other end, and an outer periphery of the inner member 61. A cylindrical outer member 62 that is spaced apart so as to cover the portion, and a helical structure 63 (holding member) positioned between them is configured.

  By providing such a connecting insulator 60, the gas supply pipe 100 to be insulated while being connected to the ladder electrode 13 in order to supply the film-forming gas to the ladder electrode 13 includes an inner member 61 and an outer member 62. Is insulated from the ladder electrode 13 to which a voltage of several hundred volts is applied under any environment such as a film forming process.

  Since the connecting insulator 60 is formed by the members 61 and 62 having a simple shape, the connecting insulator 60 can be formed smaller than the conventional one, the space around the ladder electrode 13 can be saved, the degree of freedom in design, and the film forming unit. The plasma CVD apparatus having the size can be reduced.

  Also in this embodiment, it may be changed to a leaf spring instead of the spiral structure 63, and a constraining portion such as a recess for supporting the spiral structure 63 or the leaf spring may be provided.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG.
Although it has already been described that the high-frequency cable 18 is connected to the ladder electrode 13 described in the other embodiments, in the present embodiment, it is a connection portion between the high-frequency cable 18 and the ladder electrode 13. A double-pipe connection insulator 70 (insulator) is interposed in the power supply section (connection section).

  More specifically, as shown in FIG. 7, the connecting insulator 70 having a double-pipe structure is attached to the tip of a high-frequency cable having a core wire and has the through-hole 71a for the core wire in the axial direction. An inner member 71, an outer member 72 spaced apart so as to cover the outer peripheral portion of the inner member 71, and a helical structure 73 (holding) that positions the members 71, 72 in contact with both the members 71, 72. Member).

  The high-frequency cable shown in this figure is composed of a flexible tube made of a core wire 18a, a metal mesh conductor that supplies power outside the core wire 18a, an insulator 18c, and an insulator 18d. The ladder electrode 13 is connected via a tip fitting 80.

  With such a configuration using the connecting insulator 70, the side in contact with the ladder electrode 13 to which the core wire or the like is connected and the surface of the high-frequency cable 18 are insulated by a film-cutting structure by the spiral structure 73, so Even if a film having a high conductivity adheres to and accumulates on the flexible tube 18d, which is an insulator provided on the outer peripheral portion of the cable 18, it is possible to avoid the high-frequency power charged on the ladder electrode 13 from being grounded.

  Of course, the ground fault is avoided by providing the flexible tube 18d on the outer peripheral portion of the high frequency cable 18. However, if the flexible tube 18d is in contact with other elements in the vicinity, the ground fault occurs. Probability is high. However, by providing such a connecting insulator 70, a ground fault is surely avoided and reliability is improved.

  Also in this embodiment, the helical structure 73 may be replaced with a leaf spring, and a constraining portion such as a recess that supports the helical structure 73 or the leaf spring is provided on the inner member 71 or the outer member 72. Each can be provided.

It is a disassembled perspective view explaining the structure of the film-forming unit of the plasma CVD apparatus which is a plasma processing apparatus in one Embodiment of this invention. It is a perspective view explaining the support part of the ladder electrode of the plasma CVD apparatus which is a plasma processing apparatus in the 1st Embodiment of this invention, (a) is an upper side of a ladder electrode, (b) is a lower side of a ladder electrode. It is. It is a partial section perspective view explaining composition and structure of a support insulator in a 1st embodiment of the present invention. It is a partial section perspective view explaining composition and structure of a modification of a support insulator in a 1st embodiment of the present invention. It is a partial section perspective view explaining composition and structure of the 2nd modification of a support insulator in a 1st embodiment of the present invention. It is a figure explaining the structure and structure of the ladder electrode of the plasma CVD apparatus which is a plasma processing apparatus in the 2nd Embodiment of this invention, (a) is a perspective view of a ladder electrode, (b) is the sectional drawing. is there. It is sectional drawing explaining the structure which supplies high frequency electric power to the ladder electrode of the plasma CVD apparatus which is a plasma processing apparatus in the 3rd Embodiment of this invention. It is a schematic perspective view explaining the prior art example of the plasma CVD apparatus which is a plasma processing apparatus. It is a schematic perspective view explaining the structure of the ladder electrode of the plasma CVD apparatus which is a plasma processing apparatus.

Explanation of symbols

10 Plasma CVD equipment (plasma processing equipment)
11 Vacuum chamber 12 Film forming chamber (processing chamber)
13 Ladder electrode (electrode, conductor)
13a Power feeding rod 14 Film forming unit 15 Heater cover 16 Substrate heater 17 Depositing plate 18 High frequency cable 31 Film forming unit support base 40 Electrode upper end support insulator (insulator)
41 inner member 42 outer member 43 spiral structure (holding member)
43 'leaf spring (holding member)
50 Electrode bottom support insulator (insulator)
51 Inner member 52 Outer member 53 Spiral structure (holding member)
53 'leaf spring (holding member)
60 Connection insulator (insulator)
61 Inner member 62 Outer member 63 Spiral structure (holding member)
70 Connection insulator (insulator)
71 inner member 71a through hole 72 outer member 73 spiral structure (holding member)
D1, D2 recess (restraint)
S Clearance between inner member and outer member

Claims (5)

Used in plasma processing apparatus for performing a film on a substrate, are connected to conductors including an electrode for generating plasma met insulator that to prevent grounding of the conductor by an insulating, directly connected to the conductor An inner member made of an insulating material, a cylindrical outer member that is spaced apart so as to cover the outer periphery of the inner member, and has a shorter axial length than the inner member, and between the inner member and the outer member And a holding member that holds the positional relationship by being in contact with both the members. The outer member is supported only by the inner member via the holding member, and the holding member is in contact with the holding member. An insulator, wherein a wall portion of either the outer member or the inner member is provided with a restraining portion that supports and holds the holding member . The insulator according to claim 1, wherein the inner member includes a flow path through which a fluid is conducted.   The insulator according to claim 1 or 2, wherein the holding member is a helical structure surrounding an outer peripheral portion of the inner member.   The insulator according to claim 1 or 2, wherein the holding member is a leaf spring. A plasma processing apparatus having a gas supply electrode connected to a high-frequency cable to generate plasma in a processing chamber and supplying a film-forming gas to a substrate installed in the processing chamber. A plasma processing apparatus, wherein the working gas supply line is connected via the insulator according to any one of claims 1 to 4 .

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