JPH06116761A - Device for simultaneous etching on both sides - Google Patents

Abstract

PURPOSE:To uniformly etch a material to be etched from its inside to its outer peripheral part. CONSTITUTION:An electrode 40 which is a conductive material consists of an annular and flat material. The electrode 40 is formed in inside diameter to nearly the same shape as the outside shape of a disk D. The electrode 40 is formed with holes at 3 points and is mounted by inserting these holes onto the shaft parts of stud parts 41 consisting of isolating materials. The holes H formed on the electrode 40 come into contact with the outer peripheral surface of the disk D into when the electrode 40 is held between a high-frequency electrode 62 and a substrate holding part 55a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided simultaneous etching apparatus for etching the surface of a substrate such as a hard disk.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional substrate holder.
0, on which a large number of substrate holding portions 31 are formed. As shown in FIG. 4, the details of the substrate holding portion 31 are formed with a substantially circular opening 32 , and an arcuate groove 33 is formed in a lower region of the opening 32 within an angular range shown by a dotted line.
Are formed. A doughnut-shaped substrate D, such as a hard disk, on which the carbon film is etched on both sides, is held on this.

FIG. 5 shows that the substrate D is held in the groove 33. The substrate holder 30 holding the substrate D is carried into the etching chamber B from the preparation chamber A by the drive mechanism 37, as shown in FIG. In the etching chamber B , as shown in FIG. 7, the substrate holder 30, the ground electrode 39,
39 are arranged to face each other, and the ground electrodes 39, 3
At the four corners of FIG. 9, the alternate long and short dash line in FIG. 6 is shown (the earth electrode 39 is present in front of the substrate holder 30, but this is indicated by the alternate long and short dash line).
As shown by, the opening 39 larger than the diameter of the high frequency electrode 38
a is formed, and the high frequency electrode 38 penetrates therethrough and is provided in a non-contact state so as to face the substrate holder 30. With such a structure, when the etching chamber B has a predetermined etching atmosphere, the high-frequency electrode 38 moves toward the substrate holder side in the axial direction (dashed line) to come into contact with the surface of the substrate holder 30 which is a conductor. A high-frequency potential is applied to this, and a high-frequency potential is applied to the substrate D through the substrate holder 30 to etch the substrate D.

In such a conventional double-sided simultaneous etching apparatus, a plurality of substrates are held in a substrate holder and a high-frequency potential is applied to the substrates via the substrate holder without directly applying the high-frequency potential to the substrates. At the same time, both sides of the substrate were etched. This is because the outer circumference of the substrate has a specially shaped part called "champfer", and it is not possible to have a structure that holds the outer peripheral surface evenly, and it is placed in the groove of the substrate holder at a limited place on the outer circumference of the substrate. .
Therefore, the contact between the groove of the substrate holder and each substrate or the degree of contact is not uniform, and the high-frequency potential is not evenly transmitted from the substrate holder to each substrate. Further, since the high frequency potential is applied from a limited portion of the outer peripheral portion of the substrate, there is a problem that the potential distribution of the substrate cannot be made concentric.

As described above, the present applicant has developed the following double-sided simultaneous etching apparatus in order to solve the problem in view of the double-sided simultaneous etching apparatus.

FIG. 8 shows a double-sided simultaneous etching apparatus 1 capable of simultaneously etching both front and back surfaces of a substrate.
In the double-sided simultaneous etching apparatus 1, a cylindrical rod 10 vertically penetrates a bottom wall portion 6 of a vacuum chamber 3 and is hermetically arranged. The rod 10 is composed of a hollow cylindrical high frequency electrode 14 electrically isolated from the vacuum chamber 3, and an earth shield 10 'surrounding the high frequency electrode 14, and the upper end of the high frequency electrode 14 is closer to the upper end of the earth shield 10'. It projects slightly upward. Although not shown, cooling water can flow into the internal space 14a of the high-frequency electrode 14 as needed. Further, as shown in the drawing, a substrate D (for example, a hard disk) to be etched is placed on the upper end of the high frequency electrode 14.

The rod 10 consisting of the high frequency electrode 14 and the earth shield 10 'is vertically movable as shown by an arrow a, and the high frequency electrode 14 is connected to a high frequency power source 19 so that a high frequency potential can be applied. The ground shield 10 'is connected to the ground. In addition, above the high-frequency electrode 14, a cylindrical rod 9 having a substrate holding portion 9a formed therein is provided opposite to the upper end surface of the insulator 9b.
It is fixed to the upper lid 4 via the earth shield 9 ′ around the rod 9 except for the tip of the substrate holding portion 9a.
It is surrounded. Although the drawing shows the state in which the rod 10 is positioned downward, when the rod 10 moves upward, the substrate D is sandwiched between the high frequency electrode 14 of the rod 10 and the substrate holding portion 9a of the rod 9.

A pair of flat plate-shaped ground electrodes 11 and 12 are provided in the vacuum chamber 3, and both have a donut-shaped flat plate shape like the substrate D. The ground electrode 11 arranged parallel to the etching surface of the substrate D and arranged on the upper side is penetrated by the rod 9 through the opening formed therein, and the lower ground electrode 12 is formed on this. The opening is provided so as to penetrate the rod 10.

Further, the double-sided simultaneous etching apparatus 1 is provided with a gas inlet 8 in the wall portion 5 for making the inside of the etching chamber C a predetermined etchant gas atmosphere, and is connected to the etching apparatus 1 via a partition valve 13. A transport mechanism 16 for loading and transporting the substrate D is provided in the transport device 2,
As a result, the substrate D is placed on the high frequency electrode 14. Further, an exhaust port 7 is provided in the bottom wall portion 6 of the vacuum chamber 3, and an exhaust pump 18 is connected via a partition valve 15.

In the double-sided simultaneous etching apparatus having such a structure, the etching gas is introduced into the substrate D from the gas introduction port 8 and the etching chamber C is evacuated to a predetermined pressure by the vacuum pump 18 via the valve 15. When the rod 10 is transferred to just above the high-frequency electrode 14, the rod 10 is moved upward by a driving means (not shown), and when the substrate D comes into contact with the substrate holding portion 9a at the lower end portion of the rod 9, the rod 10 moves to its position. To stand still. As a result, the substrate D is sandwiched between the high frequency electrode 14 and the substrate holding portion 9a.

Next, when the etching chamber C has a predetermined atmosphere and pressure, a high-frequency potential is applied to the high-frequency electrode 14 from the high-frequency power source 19 to etch the etching treated surface of the substrate D. With such a configuration, the potential distribution of the substrate D can be made concentric.

[0012]

In the conventional double-sided simultaneous etching apparatus, the outer peripheral portion of the substrate is larger than the central portion of the substrate.
The etching rate is remarkably increased, and the uniformity of etching distribution in the substrate cannot be maintained. This is due to the fact that the central part of the substrate and the outer peripheral part are not exposed to a uniform electric field due to the influence of the fringing field at the outer peripheral end of the substrate. For example, in a hard disk, since elements that exhibit performance are formed from the central part of the substrate to a few mm inside the outer peripheral edge, non-uniformity of etching in the outer peripheral part causes a hindrance to the function of the hard disk. .

The present invention has been made in view of the above problems, and an object of the present invention is to provide a double-sided simultaneous etching apparatus which can obtain uniform etching characteristics on the entire substrate surface regardless of the central portion and the outer peripheral portion of the substrate surface.

[0014]

The above object is to dispose a high-frequency electrode for applying a high-frequency potential to a disk-shaped material to be etched in a vacuum chamber, and a high-frequency electrode arranged in parallel with an etching-treated surface of the material to be etched. In the double-sided simultaneous etching apparatus provided with the grounded electrode, a flat plate made of a conductive material having an opening having substantially the same shape as the material to be etched is provided on the outer periphery of the material to be etched, and the flat plate and the material to be etched are provided. This is achieved by a double-sided simultaneous etching apparatus characterized in that the materials are arranged at least partially in abutment.

[0015]

Since a flat plate made of a conductive material having an opening having substantially the same shape as the material to be etched is provided on the outer periphery of the material to be etched and the flat plate and the material to be etched are brought into contact with each other, the center of the material to be etched is The peripheral portion and the outer peripheral portion are exposed to a uniform electric field, the progress of active etching in the outer peripheral portion of the material to be etched is suppressed, and uniform etching characteristics can be obtained from the central portion to the outer peripheral portion of the material to be etched.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A double-sided simultaneous etching apparatus in embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, the material to be etched will be described using the substrate D which is a hard disk as in the conventional example.

FIG. 1 shows an etching apparatus 50 according to the present invention.
The etching apparatus 50 has a bottom wall 53 of a vacuum chamber 51, and a cylindrical rod 56 penetrating the bottom wall 53. The rod 56 is attached to the bottom wall 53 so as to be vertically slidable and airtight as shown by an arrow b. The rod 56 is composed of a hollow cylindrical high-frequency electrode 62 electrically isolated from the vacuum chamber 51, and an earth shield 56 'surrounding the high-frequency electrode 62. The upper end of the high-frequency electrode 62 is the upper end of the earth shield 56'. It projects slightly above the part. Internal space 62 of high frequency electrode 62
Although not shown in a, cooling water can be flowed as necessary. The figure shows that the substrate D is already fixed on the high-frequency electrode 62. As shown in FIG. 3, the substrate D has an annular shape such as a hard disk in which an opening h is formed, the surface is covered with a carbon film, and both front and back surfaces are etched.

As shown in FIG. 1, a cylindrical rod 55 is provided on the upper surface of the high-frequency electrode 62, that is, on the mounting surface of the substrate D so as to face it. The rod 55 is composed of an insulator 55b provided with a substrate holding portion 55a at its tip and an earth shield 55 'surrounding the insulator 55b except for the tip portion of the substrate holding portion 55a. The rod 55 is formed on a flat earth electrode 57. It is fixed to the upper lid 54 of the vacuum chamber 51 through the circular opening, and the opening of the ground electrode 57 is formed so that there is a gap that does not contact the outer peripheral surface of the rod 55. The ground electrode 57 is arranged so as to be parallel to the surface of the substrate D when the substrate D is sandwiched between the high frequency electrode 62 and the substrate holding portion 55a as shown in FIG. Further, a flat plate-shaped ground electrode 58 is provided below the ground electrode 57 so as to face it, and similarly to the ground electrode 57, when the rod 56 penetrates the opening formed therein, the rod 56 is also provided. The opening is formed so as to leave a gap that does not come into contact with the outer peripheral surface of the substrate D, and is arranged so as to be parallel to the surface of the substrate D when the substrate D is sandwiched between the high frequency electrode 62 and the substrate holding portion 55a. And a support member 58 that is a conductor
It is attached to the bottom wall portion 53 via a and 58a.

As shown in FIG. 1 or 3, the vacuum chamber 5
In the bottom wall portion 53 of No. 1, three cylindrical stud portions 41 are arranged at 120 ° intervals with reference to the center point of the high frequency electrode 62. The stud portions 41 have the same structure, and as shown in detail in FIG. 2, a columnar column 42 is vertically fixed to the bottom wall 53, and the column 42 does not contact the ground electrode 58. Therefore, the ground electrode 58 is provided with an opening 5 through which the column 42 is penetrated.
8a is formed at three places. An insulating material 43 having a shaft 45 implanted therein is fixed to the upper portion of the support column 42, and a substrate potential expanding compensating electrode 40 (hereinafter referred to as an electrode 40) is formed on the shaft portion 45. Through the opening,
It is placed on the insulating material 43. The electrode 40 is made of this insulating material 43
And 44, and the insulating material 44 receives the spring force of a spring 46 stretched in a compressed state between the insulating material 44 and the spring bearing 47 to attach the electrode 40 to the insulating material 43 side. Energize. Further, as shown in FIG. 2, the insulating material 44 is a cylindrical body having a convex sectional shape, and the convex protruding portion is inserted into the opening formed in the electrode 40 to prevent the electrode 40 from being displaced. I'm out.

The electrode 40 is made of a conductive material, and the electrode 40 shown in FIG.
As shown in FIG. 3, the plate is annular and has a thickness substantially the same as that of the substrate D, and the inner diameter of the hole H, which is an inner hole, is formed substantially the same as the outer diameter of the substrate D. In addition, as shown in FIG.
A hole is formed in the hole H of 0, and when the rod 56 moves upward as shown in the drawing, the substrate D is fitted into this step, but the chamfer at the outer peripheral edge of the substrate D is the step. The upper surface of the outer peripheral portion of the substrate D lightly touches the electrode 40 without touching. The degree of contact with the electrode 40 on the upper surface of the outer peripheral portion of the substrate D does not need to be uniform in the peripheral portion, and may be in partial contact. Since the electrode 40 is attached via the insulating materials 43 and 44, it is in a floating state when it is not in contact with the substrate D, and has its potential when a high-frequency power source is applied to the substrate.

Although not shown, the vacuum chamber 51 is provided with a gas inlet port in the wall 52, an exhaust port in the bottom wall 53, and an exhaust pump connected through a partition valve. There is.

The structure of the double-sided simultaneous etching apparatus 50 according to the first embodiment of the present invention has been described above. Next, its operation will be described.

In the double-sided simultaneous etching apparatus 50, when the substrate D is transferred onto the high-frequency electrode 62 by a transfer means (not shown), the rod 56 moves upward, so that the substrate D is removed as shown in FIG. Substrate holding portion 55 at the lower end of the rod 55
When it comes into contact with a, the rod 56 stops at that position. As a result, the substrate D is sandwiched between the high-frequency electrode 62 and the substrate holding portion 55a, and at the same time, the upper surface of the outer peripheral portion of the substrate D is in slight contact with the stepped portion of the hole H of the electrode 40. That is, it is brought into contact with a portion where a device called a chamfer is not constructed. Next, the etching chamber E in the vacuum chamber 51 is decompressed by an exhaust pump (not shown), and the etching gas is introduced from the gas inlet. Etching room E
When a predetermined atmosphere and pressure are reached, a high-frequency potential is supplied to the high-frequency electrode 62 by a high-frequency power source (not shown),
A high-frequency potential is applied to the substrate D, and the etching-processed surface of the substrate D is etched.

At this time, the potential applied to the substrate D from the high frequency electrode is also conducted to the electrode 40 which is a conductive material, and an electric field almost the same as the central portion of the substrate D is expanded to the outer peripheral portion of the substrate D, that is, , Fring generated on the outer peripheral portion of the substrate D
The influence of the ing field from the substrate outer peripheral portion to the electrode 40
The outer peripheral portion of the substrate D is exposed to substantially the same electric field as the central portion of the substrate D, and the front and back surfaces of the substrate D are uniformly etched from the central portion to the outer peripheral portion.

The etching apparatus 50 in this embodiment is a production apparatus, the stud portion 41 has a spring structure as shown in FIG. 2, and the insulating material 44 is a spring 46.
The shaft member 45 can be moved upward by resisting the spring force of. Therefore, when the etching process of the substrate D is completed and the substrate D is replaced with the next substrate D, the electrode 4
By moving 0 upward, the electrode 40 does not interfere and the substrate D can be replaced immediately. By continuously exchanging the substrates D in this manner, it is possible to mass-produce the substrates D that have been uniformly etched from the inside to the outer peripheral portion of the substrates D.

As described above, according to this embodiment, the etching rate is the same from the central portion of the substrate D to the electrode 40, the etching rate is improved, and the etching is performed uniformly, so that a high quality substrate is produced. can do. This is particularly effective when the etching distribution in the central portion and the outer peripheral portion of the substrate D must be strict.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the spring mechanism is provided on the stud portion in the explanation of the production apparatus.
When used in a batch type apparatus, the same effect can be obtained by mounting the electrode 40 as a single product on the substrate without using this stud. Further, in the above embodiment, an example in which the substrate D is placed on the high frequency electrode in the horizontal direction and the etching process is performed,
The substrate D may be held in the vertical direction for etching.

[0029]

As described above, according to the double-sided simultaneous etching apparatus of the present invention, a uniform etching distribution can be obtained from the inside of the material to be etched to the outer peripheral portion, and the quality of the material to be etched is improved. Can be made.

[Brief description of drawings]

FIG. 1 is a front view of a double-sided simultaneous etching apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view around an annular member of the etching apparatus.

FIG. 3 is a partially cutaway front view showing details of a stud of the etching apparatus.

FIG. 4 is a front view of a substrate holder of a conventional double-sided simultaneous etching apparatus.

FIG. 5 is a side view showing a substrate being held by a substrate holding portion of the substrate holder.

FIG. 6 is a view showing the inside of the etching apparatus.

FIG. 7 is a side view of the same.

FIG. 8 is a front view of an etching apparatus developed by the present applicant.

[Explanation of symbols]

 40 electrode 50 double-sided simultaneous etching device 57 ground electrode 58 ground electrode

Claims (1)

[Claims] 1. A double-sided surface provided with a high-frequency electrode for applying a high-frequency potential to a disk-shaped material to be etched in a vacuum chamber, and a ground electrode arranged parallel to an etching-treated surface of the material to be etched. In the simultaneous etching equipment,
A flat plate made of a conductive material having an opening having substantially the same shape as the material to be etched is provided on the outer periphery of the material to be etched, and the flat plate and the material to be etched are at least partially brought into contact with each other. A double-sided simultaneous etching device characterized by.