JP6607160B2 - Plasma CVD equipment - Google Patents

Description

  The present invention relates to a plasma CVD (Chemical Vapor Deposition) apparatus.

  A plasma CVD apparatus is known in which a metal ion obtained by converting a raw material gas into a plasma is adsorbed on a workpiece surface in a vacuum chamber (see Patent Document 1).

JP 7-216589 A

  Since the electrode provided in the plasma CVD apparatus is exposed to a plasma atmosphere, it becomes high temperature (about 600 ° C. or higher) and may be deformed by thermal expansion. When the electrode is deformed, the contact between the electrode and the support member that supplies power to the electrode becomes insufficient, which may cause poor conductivity. Therefore, a technique capable of suppressing contact failure between the electrode and the support member provided in the plasma CVD apparatus has been desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  (1) According to one aspect of the present invention, a plasma CVD apparatus is provided. The plasma CVD apparatus has a long electrode extending in the horizontal direction, having one end and the other end, and a gripping part for gripping a workpiece provided between the one end and the other end; A first support member that supports at least one end side of the electrode gripping portion from below; and a conductive second support member that supports at least the other end side of the electrode gripping portion from below; The electrode includes a weight portion on the other end side with respect to the second support member. According to the plasma CVD apparatus of this aspect, the electrode can be positively brought into contact with the support member by the mass of the weight portion. Therefore, contact failure between the electrode and the support member can be suppressed.

  Note that the present invention can be realized in various forms, for example, in the form of an electrode used in a plasma CVD apparatus, a film forming method using the plasma CVD apparatus, or the like.

It is a figure which shows schematic structure of a plasma CVD apparatus. It is a figure which shows schematic structure of an electrode unit. It is a top view which shows the structure of an electrode. It is a figure which shows schematic structure of the electrode unit in a 1st modification.

A. Embodiment:
FIG. 1 is a diagram showing a schematic structure of a plasma CVD apparatus 100 in one embodiment of the present invention. The plasma CVD apparatus 100 forms a thin film on the surface of the workpiece W by a plasma CVD method. The plasma CVD apparatus 100 includes a film forming chamber 110, a vacuum preliminary chamber 120, an electrode unit 130, a rod 140, and a control unit 150.

  The film formation chamber 110 is provided with a power supply unit 111 and a vacuum pump (not shown). In the film formation chamber 110, the interior and the process gas are introduced after the chamber is evacuated by a vacuum pump, and a film formation process by a plasma CVD method is performed. The power feeding unit 111 feeds predetermined power to the electrode 20 provided in the electrode unit 130. In the present embodiment, the power supply unit 111 supplies a voltage of, for example, 3000 V to the electrode 20. In the present embodiment, the film forming chamber 110 is made of a conductive material and is electrically grounded. Note that the power feeding unit 111 is insulated from the film formation chamber 110.

  A vacuum pump (not shown) is connected to the vacuum preliminary chamber 120. In the vacuum preparatory chamber 120, the workpiece W is introduced and removed, and the chamber is kept in a vacuum state by a vacuum pump, and moisture adhering to the workpiece W is removed.

  The electrode unit 130 is attached to the lower end of the rod 140. The electrode unit 130 is a mechanism for supplying power to the workpiece W. The detailed configuration of the electrode unit 130 will be described later.

  The rod 140 extends in the vertical direction. The rod 140 moves up and down in accordance with a control signal from the control unit 150, and moves the electrode unit 130 provided at the lower end between the vacuum preliminary chamber 120 and the film forming chamber 110.

  The control unit 150 is configured as a computer including a CPU and a memory. The CPU controls the operation of the rod 140, the power supply by the power supply unit 111, the operation of the vacuum pump, the introduction of various gases, and the like by executing a control program stored in the memory.

  FIG. 2 is a diagram illustrating a schematic structure of the electrode unit 130. FIG. 2 shows the electrode unit 130 lowered to the film forming chamber 110. The electrode unit 130 includes a first support member 10 a, a second support member 10 b, an electrode 20, a valve body 30, and a contact portion 40.

  The electrode 20 is a long electrode extending in the horizontal direction and having one end 20a and the other end 20b. Between the one end 20a and the other end 20b of the electrode 20, a grip portion 25 described later is provided. The electrode 20 has a circular cross section. In this embodiment, the diameter of the electrode 20 is about 10 to 15 mm. The electrode 20 is made of a material having a certain heat capacity. In the present embodiment, the electrode 20 is made of titanium (Ti), but instead of titanium, the electrode 20 may be made of any material having a somewhat large heat capacity, such as stainless steel (SUS).

  The first support member 10a supports at least the one end 20a side from the grip portion 25 of the electrode 20 from below. In this embodiment, it supports from an up-down direction. The second support member 10b supports the other end 20b side from the grip part 25 of the electrode 20 at least from below. In this embodiment, it supports from an up-down direction. The first support member 10a includes a collar 11a and a bolt 12a. The electrode 20 is fixed from above and below by pressing the electrode 20 toward the collar 11a with the bolt 12a. The second support member 10b includes a collar 11b and a bolt 12b. The electrode 20 is fixed from above and below by pressing the electrode 20 toward the collar 11b with the bolt 12b.

  In the present embodiment, hereinafter, the first support member 10a and the second support member 10b are collectively referred to as the support member 10. The support member 10 has a rod-like appearance extending in the vertical direction, and is made of conductive stainless steel (SUS). The support member 10 is fixed to the valve body 30 via an insulating member 31.

  The valve body 30 closes the film formation chamber 110 by partitioning the film formation chamber 110 and the vacuum preliminary chamber 120 when the workpiece W is transferred from the vacuum preliminary chamber 120 to the film formation chamber 110. The valve body 30 is made of a conductive metal material.

  The contact portion 40 is electrically connected to the electrode 20 via the first support member 10a. The contact part 40 contacts the power feeding part 111 when the workpiece W moves into the film forming chamber 110. As a result, the workpiece W becomes the same potential as the power feeding unit 111 through the electrode 20, and discharge can be performed between the workpiece W and the grounded film forming chamber 110 and between the workpiece W and the valve body 30. .

  In the present embodiment, the electrode 20 includes a weight portion 21, a flat portion 22, and a grip portion 25. In this embodiment, the weight portion 21 is provided on the other end 20b side of the second support member 10b of the electrode 20. The weight part 21 has a predetermined mass. This mass is set to a mass heavier than the total mass of the grip portion 25 and the workpiece W, for example. The flat portion 22 is flat in a direction perpendicular to the thickness direction (X-axis direction) of the electrode 20. In the present embodiment, the flat portion 22 is sandwiched between the collar 11b and the bolt 12b, and a contact area between the second support member 10b, the collar 11b, and the bolt 12b can be secured. The grip portion 25 is formed of a conductive material and grips the workpiece W. In the present embodiment, the grip portion 25 is formed in a clip shape, but is not limited to the clip shape, and may be formed in a hook shape, for example.

  FIG. 3 is a plan view showing the configuration of the electrode 20. 3, the figure which looked at the electrode 20 shown in FIG. 2 from the valve body 30 side is represented. As shown in FIG. 3, a first hole 23 and a second hole 24 are formed in the vicinity of both ends of the electrode 20, respectively. In the present embodiment, the second hole portion 24 is formed in the flat portion 22. The first hole 23 has a circular shape. The second hole 24 has a shape extending in the longitudinal direction of the electrode 20. In the present embodiment, the first hole portion 23 and the second hole portion 24 are formed as through holes that penetrate the electrode 20 in the thickness direction (X-axis direction).

  The first support member 10 a is disposed (inserted) in the first hole portion 23, and the second support member 10 b is disposed in the center portion in the longitudinal direction of the second hole portion 24. In this embodiment, the cross-sectional shape of the support member 10 is a circle. The diameter of the first hole 23 and the length of the second hole 24 in the short direction (Z-axis direction) are substantially equal to the diameter of the support member 10. Therefore, by inserting the first support member 10a into the first hole 23 and the second support member 10b into the second hole 24, the vertical direction (X-axis direction) and the horizontal direction (Y, Z-axis) of the electrode 20 are obtained. Misalignment in the direction) is suppressed.

  The length of the second hole portion 24 in the longitudinal direction (Y-axis direction) is longer than the diameter of the second support member 10b. Therefore, in a state where the second support member 10b is inserted into the second hole 24, the second hole 24 is adjacent to the second support member 10b in the horizontal direction (Y-axis direction) of the electrode 20, A gap 26 larger than the gap formed in the first hole 23 is formed. Therefore, when the electrode 20 is heated and expanded during the film formation process, at least a part of the expanded volume can be absorbed by using the gap 26. For this reason, it is possible to suppress the horizontal expansion of the electrode 20 from being restricted by the support member 10. In the present embodiment, the length in the Y-axis direction of the gap 26 formed in the second hole 24 is larger than the dimensional change in the Y-axis direction in the vicinity of the outer periphery of the electrode 20 due to thermal expansion.

  According to the plasma CVD apparatus 100 of the present embodiment, the weight of the weight part 21 is balanced with the weight applied to the second support member 10b by the work W, so that the electrode 20 is positively attached to the second support member 10b. Specifically, it can be brought into contact with the upper surface of the bolt 12b. Therefore, contact failure between the electrode 20 and the support member 10 can be suppressed.

  In addition, according to the present embodiment, since the electrode 20 has a circular cross section, it is possible to suppress the deposition residue generated by the deposition process from being deposited on the upper surface of the electrode 20. Further, even if film deposition residue adheres to the electrode 20, since the cross section is circular, it is difficult to apply stress to the deposited film residue. Therefore, it is possible to suppress the film residue from being peeled off from the electrode 20 and causing a contact failure. In addition, since the heat capacity of the electrode 20 is large to some extent, even when the electrode 20 is exposed to a plasma atmosphere and becomes high temperature, deformation due to thermal expansion is difficult to occur. Therefore, contact failure between the electrode 20 and the support member 10 can be more effectively suppressed.

B. Variations:
<First Modification>
FIG. 4 is a diagram showing a schematic structure of an electrode unit 130A in the first modification. In the above embodiment, the electrode 20 has a circular cross section, and a flat portion 22 is provided in a part thereof. On the other hand, in this modification, the entire electrode 20A is formed flat without having the flat portion 22. And the weight part 21A is provided in the other end 20b side rather than the 2nd supporting member 10b of the electrode 20A.

<Second Modification>
In the embodiment and the modification, the weight portion is provided only on the other end 20b side than the second support member 10b. On the other hand, a weight part may be provided in the both ends of an electrode.

<Third Modification>
In the said embodiment, the 1st supporting member 10a has electroconductivity. On the other hand, for example, when electric power is supplied to the electrode 20 from another conductor, the first support member 10a may not have conductivity.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the column of the summary of the invention are intended to solve the above-described problems or to achieve a part or all of the above-described effects. In order to achieve, it is possible to replace and combine as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Support member 10a ... 1st support member 10b ... 2nd support member 11a, 11b ... Collar 12a, 12b ... Bolt 20, 20A ... Electrode 20a ... One end 20b ... Other end 21, 21A ... Weight part 22 ... Flat part 23 ... 1st hole part 24 ... 2nd hole part 25 ... Grip part 26 ... Air gap 30 ... Valve element 31 ... Insulating member 40 ... Contact part 100 ... Plasma CVD apparatus 110 ... Film-forming chamber 111 ... Power supply part 120 ... Vacuum preliminary chamber 130, 130A ... Electrode unit 140 ... Rod 150 ... Control unit W ... Workpiece

Claims (1)

A plasma CVD apparatus,
A long electrode extending in the horizontal direction and having one end and the other end, and a gripping part for gripping a workpiece is provided between the one end and the other end;
A first support member that supports at least one end side of the electrode gripping portion from below;
A conductive second support member that supports at least the other end side of the electrode gripping portion from below;
The said electrode is a plasma CVD apparatus provided with a weight part in the said other end side rather than a said 2nd support member.

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