JP2726436B2 - Plasma processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a plasma processing apparatus.

(Prior Art) As this kind of plasma processing apparatus, for example, a batch type plasma CVD apparatus has a configuration as shown in FIG.

That is, a heater 2 is provided around the quartz reaction tube 1, and a plurality of electrode plates 4 serving also as susceptors for the wafer 3 are arranged in parallel in the quartz reaction tube 1.

One end of an RF power supply 5 is connected to each of the odd-numbered electrode numbers 4a, and an RF power supply 5 is connected to each of the even-numbered electrode plates 4b so that a reaction gas plasma introduced between the electrode plates 4 can be formed. The other end of the power supply 5 is connected.

As a configuration for connecting to the alternate electrode plates 4 as described above, small-diameter and large-diameter holes are formed on the left and right of each of the electrode plates 4, and the small-diameter holes of the odd-numbered electrode plates 4a are formed. And the first electrode rod inserted through all the electrode plates 4 so as not to contact the large-diameter hole of the even-numbered electrode plate 4b and the small-diameter hole of the even-numbered electrode plate 4b. And odd-numbered electrode plates
It is possible to adopt a configuration in which a second electrode rod inserted into all the electrode plates 4 is provided so as not to contact the large-diameter hole 4a.

In addition, it is inserted through the large-diameter hole of the electrode plate 4 and is inserted and supported around the first and second electrode rods so that both ends of the even-numbered or odd-numbered electrode plates 4 are in contact with each other. A hollow cylindrical insulating separator is provided to serve as a spacer between the electrode plates 4 together with the insulation.

This type of structure is specifically disclosed, for example, in U.S. Pat. No. 4,178,877.

(Problems to be Solved by the Invention) As described above, current is supplied to each electrode by contact between the first and second electrode rods and the small-diameter hole of the electrode plate 4. The size of the hole 4 often varies among the electrodes, and the electrode plate 4 is a relatively thin plate. The contact area between the inner peripheral surface of the small diameter hole and the outer peripheral surface of the electrode rod is small. In some cases, the contact with the electrode rods is poor and proper energization cannot be performed. When such a contact failure occurs, it becomes impossible to form an appropriate plasma between the electrodes, and there has been a problem that the processing yield is deteriorated.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems, and to form an appropriate plasma by reliably and alternately contacting each of the electrode plates arranged in parallel. Is to provide.

[Means for Solving the Problems] A plasma processing apparatus according to the present invention is provided with a plurality of electrode plates, which are arranged in parallel at a distance from each other and have small and large diameter holes, and an odd number. A first electrode rod inserted into all the electrode plates so as to be in contact with the second small-diameter hole and not to be in contact with the large-diameter hole of the even-numbered electrode plate; A second electrode rod inserted into the electrode plate so as not to be in contact with the large-diameter hole of the odd-numbered electrode plate; and a second electrode rod inserted into the large-diameter hole of the electrode plate and even-numbered or odd-numbered. A hollow circular insulating separator which is inserted and supported around the first and second electrode rods so that both ends thereof are in contact with the two electrode plates; and a conductive member formed on inner and end surfaces of the insulating separator. And a member.

(Function) According to the present invention, the following functions and effects are provided.

(A) In the case where a conductive member is formed on the inner surface and the end surface of the insulating separator, contact between the electrode rod and the small-diameter hole of the electrode plate should be made by another conductive path of the electrode plate-conductive member-electrode rod. Even if there is a defect, electrical connection is ensured by the above route, and contact reliability is improved.

That is, by forming a conductive member on the inner surface of the insulating separator inserted into the electrode rod, the electrode rod and the conductive member are electrically connected over a predetermined length, and the electrode rod-conductive member Can be secured. Moreover, by forming the conductive member on the end face of the insulating separator, the electrode plate contacting at both ends of the insulating separator can be electrically connected to the electrode plate in a region corresponding to the cross-sectional area of the insulating separator. As a result, the conduction path between the conductive member and the electrode plate can be secured. In this manner, a conduction path between the electrode plate, the conductive member, and the electrode rod can be secured, and contact reliability is improved.

(Example) Hereinafter, an example in which the apparatus of the present invention is applied to a batch type plasma CVD apparatus will be specifically described with reference to the drawings.

The schematic configuration of the apparatus of the present embodiment is as shown in FIG. 5 described above, but the configuration for energizing each electrode plate 4 is different.

First, the electrode plate 4 will be described. When the 6-inch semiconductor wafer 3 is to be processed, the outer diameter is, for example, 180 mm.
As shown in FIG. 3 (A), the odd-numbered electrode number 4a has, for example, a small-diameter hole 6 on the left side and a large-diameter hole 7 on the right side on a line dividing into a semicircle, as shown in FIG. Conversely, the even-numbered electrode plate 4b has a large-diameter hole 6 on the right side and a large-diameter hole 7 on the left side.

Since such an electrode plate 4 can be used upside down, only one of the electrode plates 4 shown in FIG. 3 (A) or (B) having a large-diameter hole and a small-diameter hole is used. By preparing and using the odd and even numbers upside down, they can be used in both cases of FIGS. 3 (A) and 3 (B). Further, as for the positions where the small diameter holes 6 and the large diameter holes 7 are formed, various modifications can be made such as providing them at positions below the center line.

As the arrangement of the electrode plates 4, an electrode plate 4 a having an odd usage mode and an electrode plate having an even usage mode are provided.
4b are arranged alternately, and the first and second electrode rods 10 and 12 having an outer diameter (for example, about 3 mm) that contact only the small-diameter hole 6 are connected to all the electrode plates as shown in FIG. 4 is inserted.

Here, the first and second rods 10 and 12 are connected to a separator 14 formed of an insulating member such as ceramics, for example, in order to reliably prevent contact with the large-diameter hole 7 and insulate the rod.
Is used.

The separator 14 is formed in a hollow cylindrical shape, the outer diameter of which is such that it can be inserted into the large-diameter hole 7, and the inner diameter of which can insert the first and second electrode rods 10 and 12. It is assumed that.

As shown in FIG. 1, which is an enlarged cross-sectional view of the portion A in FIG. 2, the separator 14 is provided to insulate the electrode plate 4b between two odd-numbered electrode plates 4a, 4a. Then, the separator 14 is inserted into the electrode rod 10 and disposed so as to be inserted into the large-diameter hole 7 of the electrode plate 4b, and both ends of the separator 14 are brought into contact with the electrode plates 4a, 4a. The distance between the even-numbered electrode plates 4a, 4a is set to a predetermined value, and by inserting such separators continuously along the longitudinal direction of the electrode rod 10, the parallel pitch can be maintained at equal intervals. it can.

Similarly, a separator 14 is arranged between the even-numbered electrode plates 4b and 4b through the large-diameter hole 7 of the odd-numbered electrode plate 4a.

Here, as a characteristic configuration of the apparatus of the present embodiment, as shown in FIG. 1, the separator 14 is formed by coating a conductive member such as an aluminum layer 16 on the inner peripheral surface and both end surfaces thereof to a thickness of, for example, about 0.1 mm. doing.

 Next, the operation will be described.

In this plasma CVD apparatus, as shown in FIG. 5, the semiconductor wafer 3 is supported on, for example, the front and back surfaces of each electrode plate 4 by a claw member or the like (not shown), and the inside of the quartz reaction tube 1 is heated by a heater 2.
Then, the temperature is raised to, for example, about 300 to 400 ° C., and then a reaction gas is introduced into the quartz reaction tube 1, and the RF power source 5 is driven to cause a gap between the even-numbered electrode plate 4 a and the odd-numbered electrode plate 4 b An electric field is formed, and as a result, a plasma of the reaction gas is formed, and a plasma CVD film is formed on the surface of the semiconductor wafer 3.

Here, the energization of each electrode plate 4 will be described. One end of the RF power supply 5 is connected to the first electrode rod 10, and the other end of the RF power supply 5 is connected to the second electrode rod 12. Running. Then, the first electrode rod 10
Is in contact with the small-diameter hole 6 of the even-numbered electrode plate 4b, but is insulated from the odd-numbered electrode plate 4a by the separator 14, so that only the even-numbered electrode plate 4b is provided by the first electrode rod 10. Can be energized.

On the other hand, the second electrode rod 12 is in contact with the small-diameter hole 6 of the odd-numbered electrode plate 4a, but is insulated from the even-numbered electrode plate 4b by the separator 14, so that the second electrode rod 12 Electricity can be applied only to the odd-numbered electrode plates 4a.

The above operation can be realized when the contact between the first and second electrode rods 10 and 12 and the small diameter hole 6 of the electrode plate 4 is ensured, but the size of the small diameter hole 6 is not necessarily constant. Without
Moreover, since the contact area between the inner peripheral surface of the small diameter hole 6 and the outer peripheral surface of the electrode rod 10 or 12 is small, it cannot be guaranteed that proper contact can always be ensured.

Therefore, in the present embodiment, an energizing path that does not rely on the small-diameter hole 6 is separately formed between the electrode rod 10 or 12 and the electrode plate 4 by the aluminum layer 16 formed by coating the separator 14, and the contact between the two is made. The reliability has been improved.

That is, by forming the aluminum layer 16 on the inner surface of the separator 14 inserted around the electrode rod 10 or 12, the electrode is formed over the contact length between the small-diameter hole 6 and the rod 10 or 12. The rod 10 or 12 and the aluminum layer 16 of the separator 14 are in a state of being electrically connected. In addition, the end surfaces of the separators 14 that are in contact with the even-numbered or odd-numbered electrode plates 4 are also made of the aluminum layer 16, so that a conductive path can be secured with the electrode rods 10 or 12-the aluminum layer 16-the electrode plate 4. Can be. Therefore, even if there is a contact failure between the electrode rod 10 or 12 and the small-diameter hole 6 of the electrode plate 4, the contact failure can be prevented by securing the conduction path.

Here, the conductive path as described above can be formed by forming the aluminum layer 16 only on the inner surface of the separator 14 or by contacting the electrode plate 4 in the circumferential direction by the thickness of the aluminum layer 16 formed on the inner surface. And the aluminum layer 16 is not necessarily formed up to the end face.

From the viewpoint of contact reliability, it is preferable to coat the aluminum layer 16 up to the end face of the separator 14, but from the standpoint of ease of coating, it is preferable to coat the aluminum layer 16 only on the inner surface of the separator 14.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, when the present invention is applied to plasma CVD,
The object to be processed is not limited to a semiconductor wafer, and various objects to be processed such as an LCD (Liquid Crystal Display) substrate can be used. Further, the present invention is not limited to the above-described plasma CVD, and various plasmas such as a plasma etcher can be used. It can be applied to a processing device.

Further, the conductive member formed on the separator 14 may be an aluminum layer in the case of plasma CVD which can be processed at a relatively low temperature of 300 to 400 ° C. in the case of the above-described embodiment. If processing is required, use SiC
Various materials can be employed according to the processing conditions such as.

There are various methods for forming the above-described conductive member on the hollow cylindrical separator 14. One of the methods is as follows. As shown in FIG. 4, the separator 14 is divided into two parts in advance. The separators 14a and 14b are formed in advance, and in such a state, a conductive member is formed on the inner peripheral surface and the end surface by CVD or the like, and thereafter, both are fixed to form a hollow cylindrical shape. be able to.

Further, in order to secure the electrical connection to the side wall of the above-mentioned electrode plate, it is not always necessary to form the conductive member on the separator 14, but the shape of the electrode rod is changed, for example, a flange portion is formed. It is also possible to adopt a configuration in which the surface of the flange portion is brought into direct contact with the side surface of the electrode plate to establish electrical connection.

[Effects of the Invention] According to the present invention, not only the conduction path between the electrode plate and the electrode rod but also the conduction path between the electrode rod and the conductive member and the electrode plate can be ensured. Even if the contact with the hole of the inserted electrode plate is poor, the reliability of the electrical contact between the two can be greatly improved.

Further, according to the present invention, the simple structure of simply forming a conductive layer on the inner wall surface of the insulating separator allows the insulating separator to be electrically connected even if the current path by direct contact between the electrode plate and the rod cannot be secured. An energization path can be ensured through the conductive layer.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view for explaining, in an enlarged manner, a contact portion between an electrode rod and an electrode plate when the present invention is applied to a plasma CVD apparatus, and FIG. FIGS. 3 (A) and 3 (B) are schematic explanatory views showing the entire configuration, respectively.
FIG. 4 is a schematic explanatory view for explaining an even-numbered electrode plate, FIG. 4 is a schematic perspective view for explaining one configuration example of an anti-cracked separator before forming a conductive member, and FIG. FIG. 1 is a schematic explanatory diagram for describing a schematic configuration of a plasma CVD apparatus. 3 ... object to be processed, 4 ... electrode plate, 4a ... odd-numbered electrode plate, 4b ... even-numbered electrode plate, 5 ... RF power supply, 6 ... small-diameter hole, 7 ... large-diameter hole, 10,12 ... electrode rod, 14 ... separator, 16 ... conductive member.

Claims (1)

(57) [Claims] 1. A plurality of electrode plates, which are arranged in parallel at a distance from each other and form small- and large-diameter holes, and contact with odd-numbered small-diameter holes and large-diameter holes of even-numbered electrode plates. Is the first that is inserted through all the electrode plates so that
A second electrode rod that is inserted into the electrode plate so as to be in contact with the small-diameter hole of the even-numbered electrode plate and not to contact the large-diameter hole of the odd-numbered electrode plate; A hollow circular insulating separator which is inserted around the first and second electrode rods so that both ends thereof are in contact with the even-numbered or odd-numbered electrode plates and both ends thereof are in contact with each other. A plasma processing apparatus comprising: a conductive member formed on an inner surface and an end surface of the insulating separator.