JPH0715900B2 - Dry process equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dry process device using magnetron discharge.

(Prior Art) Conventionally, a dry etching apparatus as this type of dry process apparatus is disclosed in, for example, a document: “Japanese Journal of Applied Physics (Japanese Journal o
f Applied Physics) 20 (11), 1981, pL817-820 ".

An outline of this conventional dry etching apparatus is shown in FIG. 2 and will be described.

In FIG. 2, 10 is a vacuum container, which is provided with an etching gas introducing pipe 12 and an exhaust pipe 14 communicating with a vacuum pump. In this conventional example, a part of the bottom portion of the vacuum container 10 is provided with a cathode electrode 18 through an insulating portion 16 formed of an insulating material such as Teflon.
Then, a sample to be etched, that is, a sample to be etched (hereinafter, referred to as a substrate) 20 is mounted on the cathode electrode 18, and the sample is placed in the vacuum container 10. A permanent magnet device in which N poles, S poles and N poles are sequentially arranged in a direction parallel to the substrate 20 outside the vacuum container 10 and below the substrate 20 to be mounted on the cathode electrode 18.
22 is provided so that the magnet device 22 can be reciprocated in the horizontal direction parallel to the substrate 20 (indicated by the arrow a in the figure). In addition, a radio frequency (RF) oscillator (including a power supply) 24 for supplying electromagnetic waves to the cathode electrode 18 (oscillation frequency 13.5
6MHz).

After the sample (substrate) 20 to be etched is mounted on the cathode electrode 18 in the vacuum container 10, it is sufficiently evacuated by a vacuum pump, and an etching gas is introduced into the vacuum container 10 to obtain 10 ^-2 ~
A gas pressure of about 10 ⁻³ Torr is applied, and then an electromagnetic wave is applied to the cathode electrode 18 by the RF oscillator 24 to excite the etching gas into a plasma state composed of positive ions and negative electrons. The supply of this electromagnetic wave forms an AC electric field E in a direction perpendicular to the cathode electrode 18. On the other hand, the permanent magnet device 22 forms a magnetic field B in a direction parallel to the cathode electrode at an intermediate position between the N pole and the S pole. Due to the AC electric field E and the magnetic field B which are formed in the space above the substrate 20 and are orthogonal to each other, an electron with a small mass causes a spiral cyclotron motion with a small orbital radius along the line of magnetic force,
It collides violently with a neutral etching gas to generate a high density plasma, and a magnetron discharge 26 is generated in this space.

Normally, the ionization rate of etching gas by RF discharge excitation is 10
^Although it is as small as ^{-4, the} ionization rate by magnetron discharge is about 10 ^-2, which is increased by two digits or more, which is an advantage that the etching rate is also increased by one digit or more.

(Problems to be Solved by the Invention) However, in the apparatus having such a conventional configuration, the magnetic field B formed on the sample to be etched, for example, the upper side of the substrate 20 is not a uniform magnetic field. The substrate is moved horizontally to the left and right, so that the substrate is uniformly etched. When the permanent magnet device 22 is moved in the horizontal direction, the magnetron discharge 26 also moves to the left and right, which causes a problem that the average value of the etching rate also decreases.

In order to solve this problem, an attempt was made to form a uniform magnetic field by arranging the S pole of one of the two independent magnets and the N pole of the other magnet so as to face each other. Requires a great deal of skill and labor, and a spare space for arranging such two magnets must be provided in the vacuum container, which is not advantageous in manufacturing the device.

The present invention has been made in view of the above-mentioned conventional problems. Therefore, an object of the present invention is to use a permanent magnet as a sample, for example, a sample to be etched in the case of a dry etching apparatus, or a sputtering sample in the case of a sputtering apparatus. In the case of a CVD device, a uniform magnetic field can be formed on the sample or the base without moving in a direction parallel to the base such as the substrate, and uniform etching or sputtering can be performed over almost the entire sample surface. Another object of the present invention is to provide a dry process device configured to uniformly form a film on a base.

(Means for Solving Problems) In order to achieve this object, the present invention takes the following means.

The magnetic field generator used in the present invention is a permanent magnet having a loop shape. This permanent magnet has a main magnetic pole layer having an N pole in one half of the loop outer constituent part and an S pole in the other half, and an opposite magnetic pole arrangement of the main magnetic pole layer in the loop inner constituent part. And an auxiliary magnetic pole layer having a magnetic pole arrangement.

This permanent magnet is attached inside or outside the vacuum container.
This attachment does not allow movement in a direction parallel to the sample, but is preferably arranged to rotate in a plane parallel to the sample plane using any suitable means, and thus to rotate the magnetic field. It may be configured.

Further, the attachment of the permanent magnet forms a magnetic field substantially parallel and uniform to the sample in the space above the sample, mainly in the region where the magnetron discharge is to be generated.

In a preferred embodiment of the present invention, the main magnetic pole layer may be formed by magnetizing the outer loop constituent portion and the auxiliary magnetic pole layer may be formed by magnetizing the inner loop constituent portion.

Further, in another preferred embodiment of the present invention, the main magnetic pole layer is a pre-magnetized first permanent magnet, and the auxiliary magnetic pole layer is pre-magnetized and is fitted inside the first permanent magnet. You can also say

In carrying out the present invention, a permanent magnet may be provided on the cathode electrode side, an anode electrode side, or a permanent magnet may be separately provided on the cathode electrode side and the anode electrode side, as required. .

In carrying out the present invention, when the permanent magnet is mounted inside or outside the vacuum container, the height relationship between the permanent magnet and the sample may be shifted or coincident with each other. When viewed in plan from above, the samples are preferably arranged in such a relationship that the sample is located in the hollow portion inside the loop of the permanent magnet.

Further, in a preferred embodiment in which the dry process apparatus of the present invention is a dry etching apparatus or a sputtering apparatus, it is best to provide this permanent magnet on the cathode electrode side, but it is also provided on the anode electrode side or the cathode. You may provide separately on the electrode side and the anode electrode side.

Further, particularly when the plasma CVD apparatus is used, for example,
Although it is best to provide the permanent magnet on the anode electrode side, it may be provided on the cathode electrode side or separately on the cathode electrode side and the anode electrode side.

Furthermore, in a preferred embodiment of the present invention, the loop shape of the permanent magnet is preferably annular, elliptical or quadrangular.

Further, it is preferable that the permanent magnet is electrically connected to the high frequency power source or electrically grounded.

(Operation) According to the dry process device of the present invention, since the loop-shaped permanent magnet composed of the outer and inner two magnetic pole layers is used as the magnetic field generator, it is substantially formed in the hollow portion inside the loop and the space in the vicinity thereof. Form a uniform and uniform magnetic field. Therefore, this permanent magnet forms a magnetic field of uniform strength in a direction substantially parallel to and substantially parallel to the plane of the sample in any suitable space region above the sample in the vacuum container, and this magnetic field and the high-frequency AC electric field. Since it is configured to generate a magnetron discharge in the space area by means of, the high concentration plasma can be generated on the sample with high uniformity, and this sample can be etched, sputtered or deposited at high speed and with high uniformity. Can be done.

Further, since the direction of the magnetic field is almost parallel to the sample surface, that is, substantially parallel to the sample surface, it is difficult for electrons in the plasma to flow to the sample side, which makes it difficult to form an ion sheath, and therefore the self-bias voltage is about 1 It becomes as small as / 5 or less to reduce damage to the sample by incident ions.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

It should be noted that the configuration of the illustrated embodiment is only schematically shown to the extent that the present invention can be understood, and therefore the size, shape and arrangement of each component are not limited to this illustrated example. . Further, in the figure, the same components as those of the conventional apparatus shown in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

Further, in each of the following embodiments, a case where the dry process apparatus of the present invention is mainly used as a dry etching apparatus will be described, but it is clear that the apparatus of the present invention can be applied to a sputtering apparatus and a CVD apparatus.

Example of Permanent Magnet Used FIG. 3 (A) and FIG. 3 (B) are plane views for explaining an example of the constitution of a permanent magnet which is used by being incorporated in the dry process apparatus of the present invention to constitute a suitable magnetic field generator. Figure and III-I
It is sectional drawing on the II line. This loop-shaped permanent magnet 30 has an annular shape, and has an N pole (also called N magnetic pole) 32 in one half divided by the diameter and an S pole (also called S magnetic pole) in the other half. 34) is magnetized to form a main magnetic pole layer 36, and the N magnetic pole 32 and the S magnetic pole 34 mainly form the N pole 32 to the S pole 34 in and around the hollow portion inside the loop.
Magnetic field lines (indicated by solid lines with arrows in the figure)
38 is configured to be substantially parallel and have substantially uniform strength when seen in a plan view. A permanent magnet having such magnetic lines of force can be obtained, for example, when the content of Co is increased to about 30% in an alnico magnet containing Al, Ni, Co and Fe as main components. In this example, the Co content is about 30
%, The coercive force is as large as about 1000 gauss or more. Due to the large coercive force, the N magnetic pole 32 of the main magnetic pole layer 36 is formed inside the same loop-shaped permanent magnet 30 after magnetization.
The S pole 33 and the N pole 35 opposite to the S pole 34 are spontaneously magnetized to form the auxiliary magnetic pole layer 40. Therefore, the main magnetic pole layer 36 of the outer loop constituent part and the auxiliary magnetic pole layer 40 of the inner loop part constitute one loop-shaped permanent magnet, and the boundary between the two magnetic pole layers 36 and 40 is shown in FIG. And (B) are indicated by broken lines. This Co content is about 25%
When it becomes below, the coercive force becomes smaller than about 1000 gauss, which is why the S pole 33 and N of such opposite magnetic poles are formed.
There is no magnetisation of pole 35. As described above, in this embodiment, since the opposite magnetic poles S and N magnetic poles 33 and 35 of the auxiliary magnetic pole layer 40 are formed on the inner constituent side portions of the N and S magnetic poles 32 and 34 of the main magnetic pole layer 36, respectively. As shown in FIG. 3 (A), the lines of magnetic force 38 generated in the hollow portion inside the ring are more uniform in plan view, and as shown in FIG. 3 (B), from the cross-sectional direction. The magnetic field lines 38 that are seen have much better parallelism and uniformity in this hollow portion.

FIGS. 4A and 4B are a plan view and a cross-sectional view taken along the line IV-IV for explaining another configuration example of the permanent magnet 30. In the figure, the same components as those shown in FIG. 3 are designated by the same reference numerals. In this embodiment of the permanent magnet 30, the main magnetic pole layer 36 is formed of a ring-shaped first permanent magnet having a large diameter which is magnetized in advance, and the auxiliary magnetic pole layer 40 is formed.
Is formed in advance by a magnetized ring-shaped second permanent magnet having a small diameter, and the second permanent magnet is fitted inside the first permanent magnet to form a ring-shaped permanent magnet 30 as an integral structure. ing. The boundary between the main magnetic pole layer 36 and the auxiliary magnetic pole layer 40 is shown by a solid line. In this case, as a matter of course, the first and second permanent magnets have the north pole and the south pole in the radial direction, respectively, and the north and south pole portions of the first permanent magnet and the south and south poles of the second permanent magnet, respectively. The ring-shaped permanent magnets 30 are fitted and arranged so as to be in contact with each other so that the strength of the magnetic field outside the ring of the ring-shaped permanent magnet 30 is stronger than the strength of the magnetic field inside the ring. In the case of a magnet having such a double structure, the magnitude of the coercive force of the magnet used does not matter, and the two permanent magnets, the first and second permanent magnets having a small coercive force, are used to create a hollow portion. A magnetic field distribution as shown in FIGS. 4 (A) and 4 (B) can be obtained.

In the illustrated example, a ring-shaped permanent magnet is shown as an example, but it may be, for example, a square, a rectangle, an ellipse, or another loop shape.

First Embodiment FIG. 1 shows a dry process device such as a dry etching device or a sputtering device configured to perform a magnetron discharge by using, for example, an annular permanent magnet 30 composed of such a main magnetic pole layer 36 and an auxiliary magnetic pole layer 40. In the figure which shows the constitution example of the device,
The permanent magnet 30 is provided on the outer circumference of the vacuum container 10 on the cathode electrode 18 side.
An example in which is attached is shown. In this embodiment, an example using the permanent magnet 30 having the structure shown in FIG. 3 will be described, but the permanent magnet 30 having the structure shown in FIG. 4 is essentially unchanged.

In the configuration example shown in FIG. 1, the cathode electrode is provided in the vacuum container 10.
18 and the anode electrode 42 are arranged so as to face each other, and the anode electrode 42 is grounded. Further, in this embodiment, the permanent magnet 30 is arranged around the outside of the vacuum container 10 and near the surface of the cathode electrode 18 facing the anode electrode 42. In this case, the ring-shaped permanent magnet 30 is arranged so that the substrate (or wafer) 20, which is the sample to be etched, is located in the hollow portion. For example, in the example shown in FIG.
A ring-shaped permanent magnet 30 is arranged so as to surround the substrate 20 from the outside of the vacuum container 10.

When an electromagnetic wave of 13.56 MHz is applied from the RF oscillator 24 to the cathode electrode 18, a high frequency AC electric field E is formed in the space above the cathode electrode 18 in a direction substantially orthogonal to the surface of the cathode electrode 18 and thus the substrate 20. This AC electric field E and the permanent magnet 30
A magnetron discharge (shown by the broken line) 26 is formed by the magnetic field B formed between the magnetic poles N and S of. Since the plasma intensity of the magnetron discharge 26 is proportional to the intensity of the AC electric field E and the intensity of the magnetic field B, the intensity distributions of the AC electric field E and the magnetic field B are both formed substantially uniformly on the substrate 20. The plasma intensity also becomes almost uniform.

The ionization rate of plasma by magnetron discharge is
Since the ionization rate of plasma by RF discharge is higher by two digits or more, dry etching in the apparatus according to this embodiment is
It is more than one digit faster and more uniform than before.

Second Embodiment FIG. 5 is a block diagram showing, for example, a dry etching apparatus which is a second embodiment of the dry process apparatus of the present invention. This second embodiment is different from the first embodiment. This is an example in which a ring-shaped permanent magnet 30 is additionally provided on the outer circumference of the vacuum container 10 on the side of the anode electrode 42. According to this structure, the plasma intensity can be made more uniform by the action of the magnetic fields from the two permanent magnets.

Third Embodiment FIG. 6 is a block diagram showing, for example, a plasma CVD apparatus which is a third embodiment of the dry process apparatus of the present invention. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In this third embodiment, the film-forming substrate 20 is provided on the anode electrode 42, the ring-shaped permanent magnet 30 is attached to the anode electrode on the outer periphery of the vacuum container 10.
This is an example provided on the 42 side. Also in this embodiment, when an electromagnetic wave of 13.56 MHz is applied to the cathode electrode 18 from the RF oscillator 24, a high frequency AC electric field E is generated in the space below the cathode electrode 18 in a direction substantially orthogonal to the surface of the anode electrode 42 and thus the substrate 20. It is formed. The AC electric field E and the magnetic field B formed by the permanent magnet 30 form a magnetron discharge (shown by a broken line) 26. Since the plasma intensity of the magnetron discharge 26 is proportional to the intensity of the AC electric field E and the intensity of the magnetic field B, the intensity distributions of the AC electric field E and the magnetic field B are both formed substantially uniformly on the substrate 20. The plasma intensity also becomes almost uniform. In addition, 19 is a heater provided as required.

Fourth Embodiment The apparatus having the configuration shown in FIGS. 1, 5, and 6 described above is an example in which a loop-shaped permanent magnet is fixedly or rotatably provided on the outer peripheral portion of a vacuum container. It may be fixed or rotatably provided inside the vacuum container. In this case, the permanent magnets can be appropriately provided on one or both of the cathode electrode side and the anode electrode side according to the design.

FIG. 7 shows that the ring-shaped permanent magnet 30 is directly connected to the cathode electrode.
18 is a configuration diagram showing an embodiment of a dry etching apparatus provided on the surface of the cathode electrode 18 facing the anode electrode 42 in particular. FIG. Even with such a configuration, the plasma intensity in the upper region of the sample 20 can be made substantially uniform.

Modifications It is obvious that the present invention is not limited to the embodiments described above, and that many modifications and changes can be made.

For example, in a vacuum container, the loop-shaped permanent magnet can be directly installed on the cathode electrode or the anode electrode depending on the design, but in that case, it may be installed on the upper surface or the lower surface of these electrodes, or May be provided by embedding a part or all of these electrodes.

In addition, instead of installing this loop-shaped permanent magnet directly on the cathode electrode or anode electrode, the loop-shaped permanent magnet is placed slightly floating so that it does not come into contact with the cathode electrode or anode electrode, and high-density plasma is generated. Therefore, for example, by making the flow of the sputtering gas smooth, it is possible to perform highly uniform and high-speed sputtering deposition.

For example, in the above-mentioned dry process device, the permanent magnets are fixedly provided inside or outside the vacuum container, but in the plane including these loop-shaped permanent magnets, for example, the center axis or the center of gravity of rotational symmetry is centered. By rotating the magnetic field in a plane substantially orthogonal to the AC electric field by rotating as an axis, the plasma intensity distribution on the sample, that is, the substrate to be etched, the target, or the film forming substrate becomes more uniform, and therefore the etching rate, It is possible to make the sputtering rate or the film formation rate uniform. In this case, the means for rotating the permanent magnet is not particularly limited, and the rotating means can be easily provided by using the conventional technique.
For example, when these permanent magnets are provided on the cathode electrode or the anode electrode, the cathode electrode or the anode electrode may be rotated. When the permanent magnet is not provided on the cathode electrode or the anode electrode, the holding mechanism of the permanent magnet is used to mechanically control the rotation or, for example, an electromagnetic method utilizing the repulsive force of the magnet is used to form a vacuum container. The rotation may be controlled from the outside. still,
For these rotations, the speed of rotation is not important. or,
When the cathode electrode and the anode electrode are individually provided with the above-mentioned permanent magnets, respectively, it is preferable that the S poles and the N poles, which are arranged opposite to each other, rotate in synchronization with each other so as not to shift. Good to do.

Further, in the above-described embodiment in which the loop-shaped permanent magnet is provided outside the vacuum container, the position where the permanent magnet is provided is not limited to the illustrated example, but preferably in the vacuum container,
In order to form a magnetic field having magnetic lines of force in a direction substantially parallel to the cathode electrode in the space above the cathode electrode, the loop-shaped permanent magnet is brought into contact with the vacuum container or separated from the vacuum container at an appropriate location outside the container. It is good to arrange it.

Further, the electric field (electrical vector) is orthogonal to the cathode electrode by electrically contacting the permanent magnet used in this device with a high frequency (RF) power source or electrically grounding it. Can also be held.

Further, since the anode electrode 42 is normally grounded, it is possible to stack substances formed by reacting in plasma. Particularly, in a sputtering apparatus or a plasma CVD apparatus, when it is desired to stack deposited films by sputtering with ions, direct current (DC) or high frequency (RF) is applied to the anode electrode 42.
It is also possible to apply an electric field.

Since the present invention is characterized by using a loop-shaped permanent magnet having a two-layer magnetic pole layer structure as a magnetic field generating device necessary for forming a magnetron discharge, the other components of the dry process device are limited to the above-mentioned configurations. It is not intended to be changed, but can be changed arbitrarily according to the design.

(Effects of the Invention) As is clear from the above description, according to the dry process device of the present invention, a substantially parallel and highly uniform magnetic field is applied to the hollow portion inside the loop of the loop-shaped permanent magnet or the region in the vicinity thereof. Therefore, it is possible to generate highly concentrated plasma with high uniformity on the sample to be etched, the target sample, or the sample to be film-formed. Therefore, etching, sputtering or CVD film formation can be performed on these samples at high speed and with high uniformity.

Further, according to the dry process apparatus of the present invention, since the magnetic field is formed in the direction substantially parallel to the sample, electrons in the plasma are less likely to flow to the sample side, and thus the ion sheath is less likely to be formed, so that the self-bias The voltage is reduced to 1/5 or less. As a result, the damage to the sample caused by the incident ions is reduced, and therefore the dry process apparatus of the present invention is suitable for use in gates, trench etching, or vapor deposition of wiring materials which require low-damage etching or rapid deposition. .

Further, according to the present invention, the device can be downsized.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a first embodiment of a dry process apparatus of the present invention, FIG. 2 is a block diagram showing a conventional dry etching apparatus, and FIGS. 3 (A) and 3 (B) show the present invention. Is a schematic plan view showing an example of a loop-shaped permanent magnet used in FIG. 4 and a cross-sectional view taken along line III-III. FIGS. 4 (A) and 4 (B) are loop-shaped permanent magnets used in the present invention. FIG. 6 is a schematic plan view showing another example of the present invention and a cross-sectional view taken along line IV-IV. FIG. 5 is a configuration diagram schematically showing a second embodiment of the dry process apparatus of the present invention. FIG. 7 is a configuration diagram for explaining a third embodiment of the dry process device of the present invention, and FIG. 7 is a configuration diagram for explaining a fourth embodiment of the dry process device of the present invention. 10 …… Vacuum container, 12 …… Introduction tube 14 …… Exhaust tube, 18 …… Cathode electrode 19 …… Heater, 20 …… Sample 21 …… Reactive gas, 24 …… Radio frequency (RF) oscillator 26 …… Magntron Discharge 30 …… Looped permanent magnet 32,35 …… N pole (N magnetic pole) 33,34 …… S pole (S magnetic pole) 36 …… Main magnetic pole layer, 38 …… Magnetic field 40 …… Auxiliary magnetic pole layer, 42 ・ ・ ・... Anode electrode E ... AC electric field, B ... Magnetic field (or magnetic field).

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area H01L 21/205

Claims (12)

[Claims] 1. A magnetron discharge is generated in an upper space of a sample mounted on a cathode electrode or an anode electrode and installed in a vacuum container by an electric field generated by a power applied to the cathode electrode or the anode electrode from a power source. In a dry process device equipped with a magnetic field generator for generating a magnetic field, the magnetic field generator is a permanent magnet formed by magnetizing a permanent magnet material having an integral continuous loop shape, and this permanent magnet A main magnetic pole layer having an N pole in one half of the outer component and an S pole in the other half, and an auxiliary magnetic pole layer having a magnetic pole arrangement opposite to the magnetic pole arrangement of the main magnetic pole layer in the loop inner component, respectively. And is provided, and the permanent magnet is fixedly provided inside or outside the vacuum container or is provided so as to be rotatable in a plane parallel to the sample plane. Dry process and wherein the door. 2. A magnetic recording medium according to claim 1, wherein the main magnetic pole layer is magnetized to a loop outer side constituent portion, and the auxiliary magnetic pole layer is magnetized to a loop inner side constituent portion. Dry process equipment. 3. The main magnetic pole layer is a pre-magnetized first permanent magnet, and the auxiliary magnetic pole layer is a pre-magnetized second permanent magnet fitted inside the first permanent magnet. The dry process apparatus according to claim 1. 4. The dry process apparatus according to claim 1, wherein the permanent magnet is provided on the cathode electrode side. 5. The dry process apparatus according to claim 1, wherein the permanent magnet is provided on the anode electrode side. 6. The dry process apparatus according to claim 1, wherein the permanent magnets are individually provided on the cathode electrode side and the anode electrode side. 7. The dry process apparatus according to claim 1, wherein the loop shape of the permanent magnet is an annular shape, an elliptical shape, or a quadrangular shape. 8. The dry process apparatus according to claim 1, wherein the permanent magnet is electrically connected to the power source. 9. The dry process apparatus according to claim 1, wherein the permanent magnet is electrically grounded. 10. The dry process apparatus according to claim 1, wherein dry etching is performed using the sample as a sample to be etched. 11. The dry process apparatus according to claim 1, wherein the sample is used as a target sample for sputtering vapor deposition. 12. A plasma using the sample as a base for film formation.
A dry process apparatus according to any one of claims 1 to 9, characterized by performing a CVD process.