JPS63276226A - Dry processor - Google Patents

Abstract

PURPOSE:To produce plasma in high concentration and homogeneity on a specimen to be etched for CVD deposition process at high speed and in high homogeneity by a method wherein a magnetic field in high homogeneity is formed in a hollow part inside a loop of loopy magnet or nearby region thereof. CONSTITUTION:A magnet is composed of a main magnet pole part 36 comprising a permanent magnet with N polarity in one half part and S polarity in the other half part as well as an auxiliary magnetic pole 40 made of ferromagnetic material having no coercive force. When a cathode 18 is impressed with electromagnetic wave of 13.56 MHz from an RF oscillator 24, a high-frequency AC electric field E is formed in the direction almost orthogonal to the surface of a substrate 20 toward the electrode 18 in the space above the electrode 18. The magnetron discharge 26 is formed by the electric field E and the magnetic field B. The plasma intensity in the discharge part 26 is proportional to the intensities of electric field E and magnetic field B to make the plasma intensity almost homogeneous. Through these procedures, the CVD deposition process can be performed at high speed and in high homogeneity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application 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 has been described, for example, in the literature: "Japanese Journal of Azolide Physics".
Journal of Applied Physics
s) 20(11), 1981, pL 817-820
” is disclosed.

This conventional dry etching apparatus is schematically shown in FIG. 2, and will be described below.

In FIG. 2, reference numeral 10 denotes a vacuum vessel, which is provided with an etching gas introduction pipe 12 and an exhaust pipe 14 communicating with a vacuum pump. In this conventional example, a part of the bottom of the vacuum container 10 is formed as a cathode electrode 18 via an insulating part 16 made of an insulating material such as Teflon, and a sample to be etched, that is, a sample to be etched, is formed on the cathode electrode 18. A sample (hereinafter referred to as a substrate as an example) 20 is mounted and placed in the vacuum container 10. A permanent magnet device in which an N pole, an S pole, and an N pole are sequentially arranged in a direction parallel to the substrate 20 on the outside of the vacuum container 10 and below the substrate 20 to be mounted on the cathode electrode 18. 22 is provided, and the magnet device 22 can be reciprocated in a horizontal direction parallel to the substrate 20 (indicated by arrow a in the figure). Furthermore, a radio frequency (RF) oscillator (including a power supply) 24 (oscillation frequency: 13.56 MHz) is used to supply electromagnetic waves to the cathode electrode 18.
).

After the sample to be etched (substrate) 2o is mounted on the cathode electrode 18 in the vacuum chamber 10, it is sufficiently evacuated using a vacuum pump, and the etching gas is introduced into the vacuum chamber 10 at a temperature of about 10-2 to 10-3 Torr. The gas pressure is increased, and then electromagnetic waves are applied to the cathode electrode 18 by the RF oscillator 24 to excite the etching gas into a plasma consisting of positive ions and negative electrons. By supplying this electromagnetic wave, an alternating current electric field E in a direction perpendicular to the cathode electrode 18 is generated.
is formed. On the other hand, a magnetic field B in a direction parallel to the cathode electrode is generated by the permanent magnet device 22 at a position between the N pole and the S pole.
is formed. Due to the alternating current electric field E and magnetic field B, which are orthogonal to each other, formed in the space above the substrate 2θ, the light-mass electrons cause a spiral cyclotron motion with a small orbital radius along the lines of magnetic force, and a neutral It violently collides with the etching gas to generate high-density plasma and generates a magnetron discharge 26 in this space.

Etching gas ionization rate H due to normal RF discharge excitation
Although it is as small as about 10, the ionization rate due to magnetron discharge increases by more than two orders of magnitude to about 10-2, which has the advantage that the etching rate also increases by more than one order of magnitude.

(Problems to be Solved by the Invention) However, in an apparatus having such a conventional configuration, the magnetic field B formed above the sample to be etched, for example, the substrate 2o, is not a uniform magnetic field. The substrate is etched uniformly by moving it horizontally and laterally with respect to the surface. When the permanent magnet device 22 is moved horizontally, the magnetron discharge 26 also moves 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 two independent magnets and the N pole of the other magnet to face each other, but the formation of a uniform magnetic field was difficult. This method requires considerable skill and labor, and furthermore, a spare space must be provided in the vacuum container for arranging two such magnets, so there is little advantage in manufacturing the device.

The present invention has been made in view of the above-mentioned conventional problems, and 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 device, and a sputtering device in the case of a snot or ivy device. In the case of a CVD device, a uniform magnetic field is formed on the sample or the substrate without moving it in a direction parallel to the substrate or the substrate, and uniform etching or snocuttering is performed over almost the entire surface of the sample. It is an object of the present invention to provide a dry process apparatus configured to perform the dry process or to uniformly form a film on a substrate.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention uses a magnetic field generator of a dry process apparatus as a magnet having a loop shape, and one half of the magnet has an N pole. with S in the other half
It has a composite structure including a main magnetic pole part made of a permanent magnet having a pole, and an auxiliary magnetic pole part made of a ferromagnetic material having no coercive force.

This permanent magnet is attached and attached to the inside or outside of the vacuum container. This mounting is such that it cannot be moved in a direction parallel to the sample, but is preferably constructed so that it can rotate in a plane parallel to the sample plane by any suitable means, thus rotating the magnetic field. It may be configured as follows.

Further, by attaching the permanent magnet, a uniform magnetic field substantially parallel to the sample is formed in the space above the sample, mainly in the region where magnetron discharge is to be generated.

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

In carrying out this invention, when this magnet is attached to the inside or outside of a vacuum container, the height relationship between the magnet and the sample may be different or the same, but the height relationship between the permanent magnet and the sample may be different. When these are viewed from above in a plan view, it is preferable to arrange them with each other in such a relationship that the sample is located in the hollow part inside the loop of the magnet.

Furthermore, the dry processing apparatus of the present invention may be used as a drying, processing apparatus or a switching apparatus. In a preferred embodiment of the ivy device, it is best to provide this magnet on the cathode side, but it may also be provided on the anode side, or separately on the cathode and anode sides. Also good.

In addition, especially when using a plasma CVD apparatus, for example, it is best to provide the magnet on the anode electrode side, but it is also possible to provide the magnet on the cathode electrode side, or separately on the cathode electrode side and the anode electrode side. Also good.

Further, in a preferred embodiment of the present invention, the loop shape of the magnet is preferably annular, elliptical, or square.

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

(Function) According to the dry process apparatus of the present invention, a magnet having a loop-shaped structure consisting of a main magnetic pole part made of a permanent magnet and an auxiliary magnetic pole part made of a ferromagnetic material having no coercive force is used as a magnetic field generating device. Therefore, a substantially parallel and uniform magnetic field is formed in the hollow part inside the loop and the space around it. Therefore, the magnet forms a magnetic field of uniform strength in a direction approximately parallel to the surface of the sample in any suitable spatial area above the sample in the vacuum container, and this magnetic field is combined with a high-frequency alternating electric field. Since the structure is configured to generate magnetron discharge in the spatial region, high-concentration plasma is generated highly uniformly on the sample, and the sample is etched, scorched, splattered, or film-formed at high speed and highly uniformly. I can do it.

In addition, since the direction of the magnetic field is approximately parallel to the sample surface, electrons in the plasma are difficult to flow toward the sample, and therefore, an ion sheath is difficult to form. Therefore, the self-bias voltage is approximately 115 This reduces the damage caused by incident ions to the sample.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

It should be noted that the configuration of the illustrated embodiment is only shown schematically to the extent that the present invention can be understood, and therefore, the dimensions, shapes, and arrangement relationships of each component are not limited only to this illustrated example. . In addition, in the figure, the same reference numerals are given to the same components as those of the conventional device shown in FIG. 2, and detailed explanation thereof will be omitted.

Further, in each of the following embodiments, the case where the dry process apparatus of the present invention is mainly used as a dry etching apparatus will be explained.
It is clear that the invention can also be applied to devices.

Embodiments of magnets used FIGS. 3(A) and 3(B) are plan views illustrating a first configuration example of a magnet that is incorporated into the dry process apparatus of the present invention to constitute a preferred magnetic field generating device. and a cross-sectional view along the line ■-■. This loop-shaped magnet 30 has a ring shape, and is divided into two halves by the diameter, with an N pole 32 in one half and a S pole 34 in the other half. A main magnetic pole layer 36 is formed, and these N magnetic poles 3
2 and the S magnetic pole 34, a line of magnetic force 38 (indicated by a solid line with an arrow in the figure) directed from the N pole 32 to the S pole 34 mainly exists in the hollow part inside the loop and its vicinity when viewed from above. It is constructed so that it is approximately parallel and has approximately uniform strength. Permanent magnets with such magnetic field lines - for example, have At as the main component.

Contains Ni, Co, and Fe. In addition, the auxiliary magnetic layer 40 is formed of a small-diameter ring-shaped magnetic material made of a ferromagnetic material such as iron that does not have coercive force, and the ring-shaped magnetic material is fitted inside the ring-shaped permanent magnet to form an integrated structure. It has a structure in which a ring-shaped magnet 30 is formed. The boundary between the main magnetic layer 36 and the auxiliary magnetic layer 40 is shown by a solid line. In this case, the main magnetic pole layer 36 has an N pole and an S pole in the radial direction, and the ring-shaped magnetic bodies in contact with the N pole and the S pole form opposite magnetic S poles and N poles, respectively, by magnetic induction. As shown in Fig. 3 (N), the magnetic lines of force 38 generated in the hollow part inside the ring are more uniform when viewed in plan, and as shown in Fig. 3 (B), when viewed from the cross-sectional direction. The magnetic lines of force 38 have considerably improved parallelism and uniformity in this hollow portion.

In the illustrated example, the main magnetic pole layer 36 and the auxiliary magnetic pole layer 40
Although ring-shaped permanent magnets and magnetic bodies are shown as examples, examples include squares and rectangles.

It may have an elliptical shape or other loop shape.

In the structure of ring-shaped permanent magnets and magnetic materials, the magnets and magnetic materials are subdivided to the extent that their functions are not significantly changed, and negligible gaps are provided between the subdivided magnets, or the machine NQ is 'frIt may be packed with a substance to the extent that it does not change significantly.

FIGS. 4(A) and 4(B) are a plan view and a sectional view taken along the line IV-IV for explaining a second configuration example of the magnet 30. FIG. In this figure, the same components as those shown in FIG. 3 are designated by the same reference numerals. Like the magnet shown in the first configuration example, the magnet 30 shown in this configuration example has a main magnetic pole layer 36 formed of a pre-magnetized dog-shaped ring-shaped permanent magnet with a diameter that is ferromagnetic and has no coercive force. The auxiliary magnetic layer 4 is made of a ring-shaped magnetic material with a smaller diameter than the body.
form 0. The magnet 30 shown in this configuration example is different from the magnet shown in the first configuration example, and has a structure in which a ring-shaped magnet 30 is formed with an auxiliary magnetic layer 40 spaced apart inside a permanent magnet (main pole layer 36). It has become. The magnetic pole position relationship and magnetic field strength relationship of the magnet 30 are the same as in the case of the magnet shown in the first configuration example. By changing the size and shape of the auxiliary magnetic layer 40, the uniformity 9 strength of the magnetic field can be adjusted, and further by changing its vertical position, the uniformity 1 strength of the magnetic field can be adjusted.

FIGS. 5A and 5B show a first modification of the loop-shaped magnet using the ring-shaped magnet 30 shown in this embodiment.

Four ring-shaped ferromagnetic plates are arranged at the lower end of the flat side of the ring-shaped magnet (main pole layer 36), and the density of the magnetic lines of force at the upper end or center is changed by pulling the lines of magnetic force downward by magnetic induction. The strength of the magnetic field can be changed.

FIGS. 6(A) and 6(B) show a second modification of the loop-shaped magnet using the ring-shaped magnet 30 shown in this embodiment.

Four ring-shaped ferromagnetic plates are placed on the outer periphery of the ring-shaped magnet (main pole layer 36), and the density of the magnetic lines of force inside the magnet is reduced by pulling the lines of magnetic force toward the outer periphery of the magnet through magnetic induction. You can change the strength of the magnetic field by changing the

, In the modified example of the loop-shaped magnet shown in FIGS. 5 and 6, when the magnetic field strength of the permanent magnet is different for each magnet,
It is possible to adjust the magnetic field strength to an appropriate magnetic field by using four ferromagnetic plates.

The magnetic field strength at the upper end or center depends on the size of the ferromagnetic plate 41,
Adjustment is possible by changing the shape or its position.

The ring-shaped magnet in FIGS. 5 and 6 may be the magnet 3θ shown in FIG. 3 or 4.

Embodiment 1 FIG. 1 shows a dry process device, such as a dryer, a ching device, or a spasitter device, configured to perform magnetron discharge using, for example, an annular magnet 30f comprising such a main magnetic pole layer 36 and an auxiliary magnetic pole layer 40. This figure shows a configuration example in which the magnet 30 is attached to the cathode electrode 18 side of the outer periphery of the vacuum container 1θ. In this embodiment, an example using the magnet 30 having the structure shown in Figure $3 will be explained.
Even if the magnet 30 has the structure shown in FIGS. 4 to 6, there is essentially no difference.

In the configuration example shown in FIG. 1, a cathode electrode 18 and an anode electrode 42 are disposed facing each other in the vacuum container 10.
This anode electrode 42 is grounded.

In this embodiment, the magnet 30 is placed around the outside of the vacuum container 10, and is placed around the anode electrode 42 of the cathode electrode 18.
Place it near the opposite surface. In this case, a sample to be etched, such as a substrate (or sea urchin/%) 2Q, is placed in the hollow part of the ring-shaped magnet 30. For example, in the example shown in FIG. 1, a vacuum container 10 is placed around the substrate 20.
A ring-shaped magnet 30f is disposed to surround the substrate 20 from the outside.

RF oscillators 24 to 13, 56 are connected to this cathode electrode 18.
When a MHz electromagnetic wave is applied, a high frequency alternating current electric field E is formed in the space above the cathode electrode 18 in a direction substantially perpendicular to the surface of the substrate 20 toward the cathode electrode 18 . A magnetron discharge (shown by a broken line) 26 is caused by this AC electric field E and a magnetic field B formed between the magnetic poles N and 8 of the magnet 30.
is formed. Since the plasma intensity of this magnetron discharge 26 portion is proportional to the intensity of the AC electric field E and the intensity of the magnetic field B, the intensity distributions of both the AC electric field E and the magnetic field B are formed almost uniformly on the substrate 20. , the plasma intensity becomes almost uniform.

Since the ionization rate of plasma caused by magnetron discharge is more than two orders of magnitude higher than the ionization rate of plasma caused by normal RF discharge, dry etching using the apparatus according to this embodiment is more than one order of magnitude faster and more uniform than conventional methods. .

Second Embodiment FIG. 7 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. The ring-shaped magnet 30 is attached to the anode electrode 42 on the outer periphery of the vacuum container 10.
This is an example of adding it to the side. If you configure it like this,
By the action of the magnetic fields from the two magnets, it is possible to make the plasma intensity even more uniform.

Third Embodiment FIG. 8 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 this figure, the same components as in FIG. 1 are designated by the same reference numerals, and detailed explanation thereof will be omitted. In this third embodiment, the film-forming substrate 20 is provided on the anode electrode 42, and the ring-shaped magnet 30 is placed on the anode electrode on the outer periphery of the vacuum vessel 10.

This is an example in which it is provided on the 42 side. In this embodiment as well, when a 13.56 MHz electromagnetic wave is applied to the cathode electrode 18 from the RF oscillator 24, a high-frequency alternating current electric field E is generated in the space below the cathode electrode 18 in the direction perpendicular to the anode electrode 42 and hence the surface of the substrate 20. is formed. This AC electric field E,
A magnetron discharge (shown in broken lines) 26 is formed by the magnetic field B formed by the magnet 30. Since the plasma intensity of this magnetron discharge 26 portion is proportional to the intensity of the AC electric field E and the intensity of the magnetic field B, the intensity distributions of both the AC electric field E and the magnetic field B are formed almost uniformly on the substrate 20. , the plasma intensity becomes almost uniform. In addition, 19
is a heater provided as required.

Fourth Embodiment The above-described apparatus shown in FIGS. 1, 7, and 8 is an example in which a loop-shaped magnet is fixed or rotatably provided on the outer periphery of a vacuum container. It may be fixed or rotatably provided inside the container. In this case, a magnet can be appropriately provided on either or both of the cathode electrode side and the anode electrode side, depending on the design.

FIG. 9 is a block diagram showing an embodiment of a dry etching device in which the ring-shaped magnet 30f is provided directly on the cathode electrode 18, particularly on the surface of the cathode electrode 18 facing the anode electrode 42. Even with this configuration, sample 2
The plasma intensity in the upper region of 0 can be made almost uniform.

Variants It is clear that the invention is not limited only to the embodiments described above, but can be made in many variations or modifications.

For example, in a vacuum container, this loop-shaped magnet can be installed directly on the cathode or anode electrode depending on the design, but in that case, it can be placed on the top or bottom of these electrodes, or A portion or the entirety thereof may be embedded in these electrodes.

In addition, instead of placing this loop-shaped magnet directly on the cathode or anode electrode, high-density plasma can be generated by placing the loop-shaped magnet slightly floating so as not to come into contact with the cathode or anode electrode. let me,
Therefore, for example, by making the sputtering gas flow smoothly, highly uniform and high-speed sputtering deposition can be performed.

For example, in the dry process equipment described above, the magnets are fixedly provided, but within the plane containing these loop-shaped magnets, for example, the magnets are rotated around a rotationally symmetrical center axis or the center of gravity as the center axis, so that an AC electric field is applied to the magnets. By rotating the magnetic field in substantially orthogonal planes, the plasma intensity distribution on the sample, i.e., the substrate to be etched, the target, or the substrate to be deposited becomes more uniform, and therefore the etching rate, sputtering rate, or deposition rate becomes more uniform. It is possible to plan for In this case, the means for rotating the magnet is not particularly limited, and the rotating means can be easily provided using conventional techniques. For example, when these magnets are provided on the cathode electrode or the anode electrode, a structure may be adopted in which the cathode electrode or the anode electrode is rotated. In addition, if a magnet is not installed on the cathode or anode electrode, the rotation can be controlled mechanically using a magnet holding mechanism, or the magnet can be inserted from outside the vacuum vessel using an electromagnetic method using the repulsive force of the magnet. The rotation may be controlled. still,
For these rotations, the rotation speed is not important. or,
When the cathode electrode and the anode electrode are individually provided with magnets as described above, it is preferable to rotate them in synchronization with each other so that there is no misalignment between the S poles and the N poles, which are arranged opposite to each other. It's good.

In addition, in the above-mentioned embodiment in which a loop-shaped magnet is provided outside the vacuum vessel, the position where the magnet is provided is not limited to the illustrated example, but it is preferably above the cathode electrode inside the vacuum vessel. It is preferable to arrange a loop-shaped magnet at an appropriate location outside the container so as to form a magnetic field having lines of magnetic force in a direction substantially parallel to the cathode electrode in the space.

Furthermore, by electrically contacting the magnet used in this device with a radio frequency (RF) power supply or electrically grounding it as required, the electric field (electric vector) f, in a direction perpendicular to the cathode electrode, can be It can also be held.

Further, since the anode electrode 42 is normally grounded, it is possible to stack materials formed by reacting in plasma. In particular, when it is desired to laminate the deposited films while irradiating them with ions in a step-by-step device or a plasma CVD device, it is also possible to apply a direct current (DC) or radio frequency (RF) electric field to the anode electrode 42. .

Since this invention is characterized by using a loop-shaped magnet having a main magnetic pole layer and an auxiliary magnetic pole layer as a magnetic field generating device necessary for forming a magnetron discharge, the other components of the dry process apparatus are as described above. The configuration is not limited to the above, 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 apparatus of the present invention, a highly uniform magnetic field can be formed in the hollow part inside the loop of the loop-shaped magnet or in the area near it. Therefore, highly concentrated plasma can be generated highly uniformly on the sample to be etched, the target sample, or the sample to be film-formed.

Therefore, it is possible to perform etching, sputtering, or CVD film formation on these samples at high speed and with high uniformity.

Furthermore, according to the dry process apparatus of the present invention, since the magnetic field is formed in a direction almost parallel to the sample, it is difficult for electrons in the plasma to flow toward the sample side, and therefore, it is difficult to form an ion sheath. The voltage becomes small, 115 or less. As a result, damage to the sample caused by incident ions is reduced, and the dry process apparatus of the present invention is particularly suitable for use in dirt or trench etching, or wiring material vapor deposition, which requires low-damage etching or high-speed vapor deposition. .

Further, according to the present invention, the device can be made smaller.

[Brief explanation of the drawing]

Figure 1 is a block diagram schematically showing a first embodiment of the dry etching apparatus of the present invention, Figure 2 is a diagram showing a conventional dry etching apparatus, and Figures 3 (A) and (B) are A schematic plan view and a sectional view taken along the line ■-■, showing a first example of the loop-shaped magnet used in the invention, and FIGS. 4(A) and (B) show the loop-shaped magnet used in the invention. A schematic plan view and a cross-sectional view taken along line IV-IV showing a second example of the magnet, and FIGS. 5(A) and (B) are a first modified example of the loop-shaped magnet used in the present invention. 6A and 6B are schematic plan views showing a second modified example of the loop magnet used in the present invention. Figure 7 is a schematic configuration diagram of a second embodiment of the dry process apparatus of the present invention, and Figure 8 is a cross-sectional view taken along the line ■-■. FIG. 9 is a block diagram illustrating a fourth embodiment of the dry process apparatus of the present invention. DESCRIPTION OF SYMBOLS 10... Vacuum container, 12... Inlet pipe, 14... Exhaust pipe, 18... Cathode electrode, 20... Sample, 21
... Reactive gas, 24 ... Radio frequency (RF) oscillator,
26... Magnetron discharge, 28... Heater, 30
... Roof-shaped magnet, 32.35 ... N pole, 33.3
4... S pole, 36... Main magnetic pole layer, 38... Lines of magnetic force, 40... Auxiliary magnetic pole layer, 42... Anode electrode, 4
1...Ferromagnetic plate, E...AC electric field, B...magnetic field (or magnetic field). Patent applicant: Oki Electric Industry Co., Ltd. Engineering Isu/Depth ↓ Shirai Pro π (Number 11 - Kasei 1 + Jm 1st to the tub of l)
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Claims (1)

[Claims] 1) A magnetron discharge is generated in a space containing a sample mounted on a cathode electrode or an anode electrode and placed in a vacuum container by an alternating electric field generated by electromagnetic waves applied to the electrode from a high frequency power source. In a dry process apparatus equipped with a magnetic field generator, the magnetic field generator is a magnet having a loop shape, and the magnet is made of a permanent magnet having an N pole in one half and an S pole in the other half. A main magnetic pole part made of a ferromagnetic material having no coercive force, and an auxiliary magnetic pole part made of a ferromagnetic material having no coercive force. A dry process device characterized in that it is installed so that it can rotate within the device. 2) The dry process apparatus according to claim 1, wherein the auxiliary magnetic pole portion is formed inside the main magnetic pole portion. 3) The dry process apparatus according to claim 1, wherein the auxiliary magnetic pole portion is formed above or below the main magnetic pole portion. 4) The dry process apparatus according to claim 1, wherein the auxiliary magnetic pole portion is formed outside the main magnetic pole portion.