JP3510041B2 - Etching equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching apparatus for simultaneously etching both front and back surfaces of a substrate such as a hard disk.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for simultaneously etching both front and back surfaces of a substrate, for example, as shown in FIG.
There is known a structure in which a high frequency electrode c for applying a high frequency potential to a substrate b such as a hard disk and ground electrodes d, d parallel to both surfaces of the substrate b are provided therein. The high-frequency electrode c is composed of a pair of rods extending through the ground electrodes d, d in the vacuum chamber a, and the substrate b placed on the substrate holder e and carried into the vacuum chamber a is Vacuum chamber a
Both ground electrodes d, d are held at the tip of the lower high-frequency electrode c which is projected and retracted from the bottom of the device by a driving device (not shown).
Of the high frequency electrode c fixed to the upper side and sandwiched as shown in the drawing. The periphery of the high frequency electrodes c, c is covered with ground rods f, f, and the lower ground rod f is formed on the lower ground electrode d to allow the substrate b to pass to the intermediate position. The closing plate h that closes the passing through hole g is fixed. At the intermediate position, an annular etching compensating structure i made of a conductive material is provided on the outer periphery of the substrate b in order to compensate for the non-uniformity of etching performed on the substrate b. Although the substrate b has a ring-like shape such as a hard disk in which the opening k is formed in the center, it may be a substrate without the opening k. Further, the apparatus shown in FIG. 1 shows the one in which the vacuum chamber is divided into two chambers by the partition wall j in order to enable the etching treatment on the two substrates b. 1 is a high frequency power supply.

When the substrate b is loaded by being placed on the substrate holder e in the vacuum chamber a, the high-frequency electrode c which stands by below.
Also, the earth rod f rises and the substrate b is lifted at its tip end to be sandwiched between it and the high frequency electrode c above, and the passage plate g of the earth electrode d below is closed by the closing plate h. Then, the inside of the vacuum chamber a is adjusted to an etching atmosphere by evacuation and introduction of an etching gas, and when a high frequency voltage is applied to the substrate b from the high frequency power sources 1 and 1, the substrate b and the ground electrodes d and d are separated from each other. At this point, plasma discharge is generated, and the etching gas composition excited thereby plunges into both surfaces of the substrate b, and both surfaces are simultaneously etched. The etching compensating structure i is a member for compensating the etching distribution in the outer peripheral portion of the substrate b, and adjusting the distance between the potential of the substrate b and the ground potential of the etching compensating structure i in the height direction. The discharge area is controlled by and is set under the optimum condition of uniformity of etching distribution of the substrate b.

[0004]

In order to simultaneously perform etching on both surfaces of the substrate as described above, it is necessary to expose the substrate surface to be etched and sandwich the substrate. When the surface portion is sandwiched by the high frequency electrodes c, the potential difference between the earth rod f and the substrate b provided on the outer periphery thereof, and the substrate b and the etching compensation structure i.
Due to the relationship that there are two structures having different potential differences with respect to the substrate b having a potential relationship with, the etching rate is different between the inner part and the outer part of the substrate b, and the nonuniformity of the etching distribution is still sufficiently improved. I found it not.

An object of the present invention is to eliminate a potential structure different from the potential of the substrate b in an apparatus for simultaneously etching both surfaces of the substrate so that a more uniform etching distribution can be obtained.

[0006]

In the present invention, a high-frequency electrode for applying a high-frequency potential to a substrate and a plate-shaped ground electrode parallel to both surfaces of the substrate are provided in a vacuum chamber, and the substrate is applied by applying the high-frequency potential. in the same time the etching performed apparatus on both sides of, the high frequency electrode, which the insulating material so that only the power supply contact portion for applying a high frequency potential is exposed with in contact with the outer peripheral edge surface of the substrate to sandwich the substrate Ring covered with
The above-mentioned object is achieved by using a substrate holding member having the shape of a circle. Preferably, the feeding contact portion is connected to the ring.
The inner circumference of the substrate holding member is shaped. Also, the substrate holding member
When the surface of the above-mentioned insulating member is covered with a metal member,
The metal member is grounded. The high-frequency electrode is composed of an annular body divided into two or more parts, each of which is provided with a power feeding contact portion that makes contact with the outer peripheral end surface of the substrate over substantially the entire circumference, and each annular body is attached to the outer peripheral end surface by a driving device. A rod having an earth potential that is movable toward and away from the plate-like ground electrode and has a through hole through which the substrate passes is formed in one of the plate-like ground electrodes, and transfers the substrate between the high frequency electrodes of the annular body through the through hole. It is preferable to provide a closing plate which is provided so as to be able to project and retract freely, and a closing plate which closes the through hole and forms the one earth electrode in a plate shape at the tip of the rod.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. 2. In FIG. 2, reference numeral 1 is composed of an upper etching section 1a and a lower conveying section 1b communicating therewith. A vacuum chamber is shown, and a high-frequency electrode 3 for contacting and applying a high-frequency potential to a substrate 2 such as a hard disk, a compact disc, a glass substrate, and a silicon wafer is provided in the etching section 1a above the vacuum chamber, and the substrate 2 Plate-shaped ground electrodes 4a and 4b are provided on both surfaces of the pair and are parallel to each other with a space therebetween. Although the hard disk having the opening 2a in the central portion as shown in FIG. 4 is used for the substrate 2, the present invention is not limited to this, and plate-shaped bodies of various shapes can be used.

The substrate 2 is mounted in a plurality of mounting holes 5a formed in the substrate holder 5 and carried into the carrying section 1b. The carrying-in is carried out by a rotary plate or a slide arm provided outside the vacuum chamber 1. And the like. At the bottom of the vacuum chamber 1 below the substrate carry-in position of the substrate holder 5 into the etching section 1a, a rod 8 of earth potential is provided which is kept airtight by a bellows 7 or the like and is raised and lowered by an external actuator. The rod 8 mounts the substrate 2 on its tip and moves up and down between the intermediate position of the ground electrodes 4a and 4b, that is, the etching position and the housing position of the mounting hole 5a of the substrate holder 5.

In order to allow the substrate 2 to be transferred to the intermediate position, a through hole 9 having a size that allows the substrate 2 to pass therethrough is formed in the lower ground electrode 4b, and the tip of the rod 8 is etched during etching. The closing plate 10 made of the same material as the earth electrode 4b
The through hole 9 is closed by the. Upper earth electrode 4
Reference symbol a is a plate-like shape, and the ground electrodes 4a and 4b are fixed to the wall surface of the vacuum chamber 1 at the ground potential by means of fixing columns.

The high-frequency electrode 3 is composed of a substrate holding member 13 which is covered with an insulating material 11 and exposes a power feeding contact portion 12 which contacts the outer peripheral end face of the substrate 2 located at an intermediate position,
An annular body in which the substrate holding member 13 is divided into two or more parts in order to contact and hold the outer peripheral end surface of the substrate 2 carried to an intermediate position parallel to the ground electrodes 4a and 4b, for example, FIG.
A sliding shaft which is composed of two divided annular bodies 13a and 13b as shown in FIG. 2 and which is connected to a drive device 14 such as an air cylinder outside the vacuum chamber 1 via a vacuum seal. 15 is provided, and when the substrate 2 is carried to the intermediate position by the rod 8, the driving device 14 causes the annular members 13 to move.
The a and 13b move forward from the retracted position to contact the outer peripheral end face of the substrate 2 to hold the substrate 2. The power supply contact portion 12 is provided on the substrate 2 to prevent the plasma potential from changing.
Only a distance L of about several mm required for contact with the inner periphery is exposed to the inner periphery and the rest is covered with an insulating material 11, and the surface thereof is further covered with a metal earth shield 16 in order to increase the mechanical strength of the annular body. Covered with. The power feeding contact portion 12 is an annular body 13.
It is connected to an external high frequency power source 17 through the insides of a and 13b and the inside of the sliding shaft 15. Although not shown, the vacuum chamber 1
Is provided with an inlet for an etching gas and an exhaust port connected to a vacuum pump via a partition valve, as in the vacuum chamber of a conventional etching apparatus.

Describing the operation of the one shown in the figure, when the substrate 2 is loaded on the substrate holder 5 by the transport means 6 and the substrate 2 is loaded into the transport compartment 1b of the vacuum chamber 1, the rod 8 causes the substrate holder 5 and the through hole 9 to pass. The substrate 2 placed on the tip thereof is carried to an intermediate position between the ground electrodes 4a and 4b.
Subsequently, the annular substrate holding members 13a and 13b forming the high-frequency electrode 3 advance from both sides, and the feeding contact portion 12 exposed on the annular inner surface contacts the outer peripheral end surface of the substrate 2 to hold the substrate 2. . Then, the rod 8 descends to a position where the closing plate 10 attached to the tip of the rod 8 forms substantially the same plane as the lower ground electrode 4b that closes the through hole 9. During this time, the inside of the etching section 1a is evacuated by a vacuum pump, and when the etching gas is introduced from the inlet and adjusted to a predetermined atmosphere and pressure, the high frequency power supply 17
Is applied from the outer peripheral end surface of the substrate 2 via the high frequency electrode 3 of the annular substrate holding member 13, and the substrate 2 and the ground electrode 4
Plasma is generated between a and 4b, and both surfaces of the substrate 2 are simultaneously etched.

Since there are no obstacles for disturbing the plasma potential near the central portions of both sides of the substrate 2 and most of the power feeding contact portion 12 is covered with the insulating material 11 and exposed only slightly, the substrate 2 The high-frequency potential applied to the substrate 2 is uniform on both sides of the substrate 2 while being hardly affected by the ground potential or the floating potential, and can be etched at the same etching rate from the outer peripheral portion to the central portion of the substrate 2. The etching rate is also improved, and it is possible to obtain a substrate having both surfaces subjected to high-quality etching.

In the above description, the substrate 2 and the ground electrodes 4a and 4b are described as being provided in a horizontal state, but they may be provided vertically.

[0014]

When by the above-described manner, the present invention exhibits a high frequency electrode to provide a high-frequency voltage so as to etch both surfaces of the substrate provided between the two ground electrodes, in contact with the outer peripheral edge surface of the substrate the Hold the substrate and cover it with an insulating material so that only the power supply contact part that applies high-frequency potential to it is exposed.
Since it is configured with an annular substrate holding member cracks, has the effect that can be RF potential applied to the substrate is etched on both sides with uniform etching distribution of ground potential and a floating potential affected hardly substrate of claim With the constitution of Item 4, the substrate can be easily held, and by adopting the constitution of Claim 5 , the potential distributions on both surfaces of the substrate can be made substantially the same, and there is an effect that both surfaces can be uniformly etched.

[Brief description of drawings]

FIG. 1 is a cut side view of a conventional example.

FIG. 2 is a cut side view of an example of an embodiment of the present invention.

3 is an enlarged cross-sectional view taken along line 3-3 of FIG.

FIG. 4 is a plan view of the substrate

[Explanation of symbols]

1 vacuum chamber, 2 substrates, 3 high frequency electrodes, 4a and 4b
Ground electrode, 8 rods, 9 through holes, 10 closing plates, 1
1 insulating material, 12 power feeding contact part, 13 substrate holding member,
13a and 13b annular body, 14 drive device

Claims (5)

(57) [Claims] 1. An apparatus in which a high-frequency electrode for applying a high-frequency potential to a substrate and a plate-shaped ground electrode parallel to both surfaces of the substrate are provided in a vacuum chamber, and both surfaces of the substrate are simultaneously etched by applying the high-frequency potential. At this high frequency electrode,
Only feeding contact portion is exposed for applying a high frequency potential to the same time in contact with the outer peripheral edge surface of the substrate to sandwich the substrate
An etching apparatus comprising an annular substrate holding member covered with an insulating material as described above . 2. The substrate holding portion, wherein the power feeding contact portion is the annular substrate holding portion.
The edging according to claim 1, which is an inner circumference of the material.
Ching device. 3. The surface of the insulating member of the substrate holding member.
Is further covered with a metal member and the metal member is grounded.
The etching apparatus according to claim 1, wherein
Place 4. The substrate holding member constituting the high-frequency electrode is formed of an annular body divided into two or more parts, each of which is provided with a power feeding contact portion that makes contact over substantially the entire circumference of the outer peripheral end surface of the substrate, 2. The etching apparatus according to claim 1, wherein each of the annular bodies can be moved back and forth toward the outer peripheral end surface by a driving device. 5. A through hole through which the substrate passes is formed in one of the plate-like ground electrodes, and a ground potential rod for transferring the substrate between the high frequency electrodes of the annular body is projected and retracted through the through hole. The etching apparatus according to claim 4 , further comprising a closing plate that is freely provided and that closes the through hole and forms the one ground electrode in a plate shape at a tip portion of the rod.