JPH10144662A - Plasma treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve magnetic field uniformity in a treating vessel of a plasma treating apparatus having a dipole ring magnet. SOLUTION: The apparatus comprises a dipole ring magnet 41 disposed round a treating vessel 3. This magnet 41 is composed of segment magnets Ml-M40 disposed elliptically round the treating vessel 3 with spacings different in location. This allows the magnetic field to be adjusted by adjusting the magnetic moment. Each segment magnet M1-M40 is identical in shape, size and structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for performing various types of plasma processing such as etching on a substrate to be processed.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, during a process such as an etching process, a sputtering process or a CVD process, a process gas is introduced into a process vessel and the process gas is turned into a plasma. Although a plasma processing apparatus configured to perform a predetermined process on a surface of a substrate to be processed, for example, a semiconductor wafer (hereinafter, referred to as a “wafer”), is used. In addition, since the diameter of a wafer has been increased, it has been particularly important in these plasma processing apparatuses to be able to perform fine processing at high speed and uniformly.

For example, in the case of an etching apparatus, for example, high-density plasma is generated in a processing vessel to improve the etching rate while enabling fine processing, and the uniformity of the etching rate in the wafer surface is improved. It is desired to be good.

In this regard, for example, Japanese Patent Laid-Open No. 6-5317
In Japanese Patent Application Publication No. 7 (JP-A) No. 7-103, there is disclosed a plasma generation apparatus including a dipole ring magnet configured by arranging a plurality of anisotropic segment magnets in an annular shape around an outer periphery of a processing container. This device is intended to improve the uniformity of the magnetic field, especially the uniformity of the magnetic field on the surface to be processed of the substrate to be processed, thereby realizing a more uniform plasma density than the conventional device using magnetron plasma. is there.

[0005]

However, the magnetic field generated by the anisotropic segment magnet forming the conventional dipole magnet has been formed as shown in FIGS. In FIG. 15, the horizontal axis represents the distance from the center of the substrate to be processed, and the vertical axis represents the intensity of the magnetic field. A curve a in FIG. 15 shows the magnetic field strength distribution in the NS direction shown in FIG. 16, and a curve b shows the magnetic field strength distribution in a direction (EW direction) orthogonal to the NS direction. FIG. 16 shows a magnetic field distribution parallel to the surface to be processed of the substrate to be processed, wherein the horizontal axis represents the NS direction,
The vertical axis indicates a direction (EW direction) orthogonal to the NS direction. The intersection of the vertical axis and the horizontal axis indicates the center of the processing surface of the processing target substrate such as a wafer.

As can be seen from FIGS. 15 and 16,
The intensity distribution of the magnetic field on the substrate to be processed formed by the dipole ring magnet had a substantially elliptical shape in which the NS direction has a short diameter and the perpendicular direction, that is, the EW direction has a long diameter.
For this reason, the NS direction and the direction E-
The magnetic field strength was different from that in the W direction, and a high-precision uniform magnetic field could not be formed over the entire surface of the substrate to be processed.

Considering the influence of the E × B drift motion of the electrons in the plasma, the electrons move from the E-pole side to the W-pole side in FIG. 16, so that the electrons accumulate on the W-pole side. To avoid this, a so-called gradient magnetic field in which the magnetic field intensity decreases from the E pole side to the W pole side,
Thus, it is necessary to change the drift direction of the electrons to suppress the accumulation of electrons on the W pole side. However, in the related art, in order to form such a gradient magnetic field, the capacity of the magnet is required for each anisotropic segment magnet. It was difficult to consider.

[0008] Therefore, it is difficult to perform more uniform plasma processing on a substrate to be processed in a conventional apparatus having a dipole ring magnet. In order to perform uniform plasma processing, the magnetic field generated by the anisotropic segment magnet forming the dipole ring magnet extends horizontally from the processing surface of the processing substrate to the plasma space above it, and is horizontal to the processing substrate. Although it is preferable that a strong magnetic field is formed, the magnetic field actually formed has a vertical component, and a curved magnetic field that is vertically convex is formed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a plasma processing apparatus having a dipole ring magnet in which a plurality of anisotropic segment magnets are annularly arranged on the outer periphery of a processing vessel. It is an object of the present invention to correct a magnetic field generated by a magnetic segment magnet, improve plasma uniformity in a processing container, and perform a desired uniform plasma processing on a substrate to be processed.

[0010]

According to a first aspect of the present invention, a processing gas is introduced into a processing vessel, and the processing gas is turned into plasma to be applied to a substrate to be processed in the processing vessel. A plasma processing apparatus comprising a dipole ring magnet in which a plurality of anisotropic segment magnets are annularly arranged on the outer periphery of a processing vessel. It is characterized by being changed from an annular shape to an elliptical shape.

As described above, by disposing the anisotropic segment magnets in an elliptical shape, in a plasma processing apparatus having a conventional dipole ring magnet in which a magnetic field is formed in an elliptical shape when viewed from a plane, the processing vessel By correcting the magnetic field formed in the substrate, the surface to be processed, its outer peripheral edge, and the surface to be processed can be made uniform at least up to a space where plasma is generated above the surface to be processed. Plasma processing can be performed.

Conventionally, it has been proposed to adjust the magnetic moment by, for example, appropriately changing the deposition of each segment magnet. However, as in the present invention, the segment magnets are arranged in an elliptical shape, and If the distance to the processing chamber space (substrate to be processed) is changed, the magnetic moment can be adjusted similarly, and as a result, the magnetic field can be adjusted. Therefore, all the segment magnets to be used can be of the same shape and size.
Since it is possible to form a dipole ring magnet using only the same anisotropic segment magnet as described above,
The same type of anisotropic segment magnet can be used even if the plasma processing apparatus is enlarged due to an increase in the size of the substrate to be processed which is expected in the future. be able to.

According to a second aspect of the present invention, there is provided an apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing predetermined processing on a substrate to be processed in the processing container. In a plasma processing apparatus provided with a dipole ring magnet in which an anisotropic segment magnet is annularly arranged on an outer periphery of a processing container, at least one of an upper end portion and a lower end portion of the anisotropic segment magnet has a magnetic field in the processing container. It is characterized in that an auxiliary magnet for correcting a vertical component is provided.

Therefore, in a plasma processing apparatus provided with a dipole ring magnet in which a plurality of anisotropic segment magnets are annularly arranged on the outer periphery of a processing vessel, the anisotropic segment magnet provided with an auxiliary magnet used in the present invention is changed. By doing so, the vertical component of the magnetic field formed in the processing container is corrected. That is, by appropriately correcting the vertical component of the magnetic field generated by the anisotropic segment magnet with this auxiliary magnet,
The central part of the upwardly convex curved magnetic field can be pressed and corrected. Therefore, it is possible to form a horizontal magnetic field on the substrate to be processed from the surface to be processed, its outer peripheral edge, and at least the plasma generation space above the surface to be processed. In addition, uniform plasma processing can be performed. In this case, the auxiliary magnet
Although a magnetic field vector formed thereby having a vertical component can be used, preferably, a magnetic field vector that is magnetized in the vertical direction can perform such correction more effectively.

Further, the invention according to claim 3 is an apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing a predetermined processing on a substrate to be processed in the processing container. In a plasma processing apparatus including a dipole ring magnet in which a plurality of anisotropic segment magnets are annularly arranged on the outer periphery of a processing container, the plurality of anisotropic segment magnets are not arranged at equal intervals. . That is, the intervals between the adjacent anisotropic segment magnets are not always the same. Therefore, for example, a so-called thinned-out arrangement is also included.

If a plurality of anisotropic segment magnets are simply arranged in an ellipse, the overall diameter of the dipole ring magnet becomes large, for example, the major axis becomes long. In this regard, as described in claim 3, by reducing the number of anisotropic segment magnets by appropriately so-called thinning, for example, while generating a desired magnetic field in the processing chamber, the dipole ring magnet can be used. The major axis of the ellipse can be shortened, and as a result, the plasma processing apparatus can be made compact. Also, when a plurality of anisotropic segment magnets are annularly arranged, fine magnetic field adjustment can be performed by appropriately adjusting the arrangement intervals, and the cost can be reduced as the number of segment magnets decreases.

Further, as described in claim 4, the arrangement of the anisotropic segment magnets is substantially elliptical, and the center of the substantially ellipse extends from the center of the substrate to be processed along the major axis direction of the ellipse. These anisotropic segment magnets may be arranged so as to be eccentric in the direction. In this case, the direction to be shifted along the long axis is a direction to avoid the concentration of electrons in the plasma, for example, according to FIG.
It is the W pole side. The term “substantially elliptical” as used herein includes not only an ellipse but also, for example, the shape of a cut surface when a cylinder is cut obliquely on a flat surface. With this configuration, it is possible to form a gradient magnetic field in which the magnetic field intensity decreases from the E-pole side to the W-pole side, which has been difficult in the past, thereby changing the drift direction of the electrons and accumulating electrons on the W-pole side. It becomes possible to suppress.

In such a case, as described in claim 5,
If the interval between the anisotropic segment magnets is set so that one side of the center of the ellipse is relatively sparse and the other side is relatively dense with respect to the short axis of the ellipse, electrons can further move to the W pole side It is possible to suppress accumulation.

Further, a magnetic body is arranged on the side surface of the dipole ring magnet and the magnetic body is further provided with a magnetic field generating means for preventing a magnetic field from leaking, so that the magnetic material is provided around the device. It is possible to eliminate the leakage magnetic field, prevent the magnetic effects of peripheral devices, and improve the degree of freedom of design and the uniformity of the magnetic field strength when constructing a multi-chamber type semiconductor device manufacturing system. it can.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an etching apparatus will be described below. FIG. 1 schematically shows a cross section of an etching apparatus 1 according to a first embodiment. Processing chamber 2 in apparatus 1
Is formed in a cylindrical processing container 3 made of anodized aluminum or the like, and the processing chamber 2 is configured to be airtightly and freely closable. The processing vessel 3 itself is grounded, for example, by being connected to a ground wire 4.

An insulating support plate 5 made of ceramic or the like is provided at the bottom of the processing chamber 2. A substrate to be processed, for example, a wafer P having a diameter of 12 inches, is mounted on the insulating support plate 5. A substantially cylindrical susceptor 6 is housed.
The susceptor 6 is made of, for example, anodized aluminum and forms a lower electrode.

The susceptor 6 is supported by a vertically movable support member 7, and is actuated by a drive source 8 such as a motor installed outside the processing container 3, as shown by a reciprocating arrow in the drawing. It can move up and down freely. FIG. 1 shows a position at the time of etching, and the susceptor 6 is driven by the driving source 8.
Can be moved down to the gate valve 9 for carrying in and out provided below the side of the processing container. A bellows 10 for ensuring airtightness is arranged on the outer periphery of the support 7.

On the susceptor 6, an electrostatic chuck (not shown) for holding the wafer P by suction is provided.
The wafer P is placed at a predetermined position on the electrostatic chuck. Also, on the outer peripheral edge of the upper surface of the susceptor 6,
An annular focus ring 11 having conductivity is provided. The focus ring 11 has a function of improving the uniformity of the plasma density around the wafer P.

An exhaust pipe 13 is provided at the bottom of the processing vessel 3 and communicates with a vacuuming means 12 such as a turbo molecular pump. For example, it is possible to evacuate to 10 mTorr. In addition, the evacuation of the processing container 3 and the maintenance of the degree of reduced pressure in the processing container 3 by the operation of the evacuation unit 12 are performed based on a detection signal from a pressure sensor (not shown) provided in the processing container 3. It is controlled automatically.

An upper electrode 22 is provided above the processing chamber 2 via an insulating material 21 made of, for example, alumina. The upper electrode 22 is made of a conductive material, for example, anodized aluminum. At least the surface 22a facing the wafer P is made of another material having conductivity with respect to a high frequency, for example, a single material. It may be formed of crystalline silicon. The upper electrode 22 has a hollow structure having a hollow portion 22b therein, and a gas inlet 23 is formed in the upper center of the upper electrode 22. The gas inlet 23 communicates with the hollow portion 22b. I have. A large number of discharge ports 22c are formed on the surface 22a facing the wafer P in order to uniformly supply the processing gas to the entire surface of the processing surface of the wafer P.

The gas inlet 23 has a gas inlet tube 24
The gas introduction pipe 24 is connected to the valve 2.
5. A processing gas supply source 27 is connected via a mass flow controller 26 for adjusting a flow rate. In the present embodiment, a predetermined processing gas, for example, a CF-based etching gas such as a CF ₄ gas or a C ₄ F ₈ gas is supplied from the processing gas supply source 27. The flow rate is adjusted by the mass flow controller 26, and the wafer P is uniformly discharged from the discharge port 22 c of the upper electrode 22.

Next, a high-frequency power supply system of the etching apparatus 1 will be described. First, a frequency of about several hundred kHz, for example, 80
First high-frequency power supply 31 that outputs high-frequency power of 0 kHz
Is supplied via a matching unit 32 having a blocking capacitor and the like. On the other hand, a second high-frequency power supply 34 that outputs a high-frequency power of 1 MHz or higher, for example, 27.12 MHz, whose frequency is higher than that of the first high-frequency power supply 31, is supplied to the upper electrode 22 via a matching unit 33. Power is supplied.

A so-called dipole ring magnet 41 according to the present embodiment is disposed on the outer periphery of the processing vessel 3 as a magnetic field generating means. This dipole ring magnet 41 is placed on an annular rotary stage 42,
As shown in FIG. 2, it has forty cylindrical segment magnets M1 to M40 arranged in an elliptical shape. These segment magnets M1 to M40 constitute an anisotropic segment magnet. In addition, each of these segment magnets M1 to M4
Although 0 is the same shape and the same size, when it is arranged on the rotary stage 42, it is arranged so that its magnetization direction is directed to a different direction as described later. And the rotary stage 4
As shown in FIG. 1, the processing container 3 itself is driven by a driving means 43 such as a motor and a transmission mechanism 44 such as a gear.
Is configured to rotate concentrically around the outer periphery of the. The direction of rotation is indicated by a rotation arrow R in FIG.

As described above, each of the segment magnets M1 to M
Since 40 has the same shape and the same size, for example, the segment magnet M1
The segment magnet M1 has a columnar shape as a whole, and is configured such that, for example, cylindrical magnet materials 51 and 52 of the same shape and the same size for magnetizing and magnetizing are closely attached in the vertical direction. Have been. These magnet materials 51 and 52 may be integrally formed from the beginning. Further, a slit may be provided between the magnet materials 51 and 52, and a non-magnetic material may be interposed as described later. By magnetizing the material thus configured and magnetizing the magnet materials 51 and 52, for example, in the directions indicated by the arrows in FIG. 3, the segment magnet M1 is configured (the tip of the arrow is N pole is shown). The magnet material 5
The magnetization directions of 1, 52 are exactly the same.

The other segment magnets M2 to M40 have exactly the same configuration as the segment magnet M1. When arranging these forty segment magnets having the same magnetization direction on the rotary stage 42, as shown in FIG. The magnetizing directions of the segment magnets M1 to M40 are set to be different so that the magnetizing direction of the segment magnets returns to the original direction (performs a full circle). For example, referring to FIG. 2, the segment magnet M1 and the segment magnet M
21 is the same magnetization direction, and the segment magnet M20 and the segment magnet M40 are the same magnetization direction. In this embodiment, the segment magnets M1 to M
Numeral 40 is set so that the magnetization directions are shifted by equal angles. Due to the arrangement of the segment magnets M1 to M40 as described above, the magnetic field vector in the processing container 3 is oriented in the direction indicated by the thick arrow in FIG.

More specifically, the segment magnets M1 to M1
As shown in FIG. 2, M40 is arranged on an elliptical locus whose major axis is in the NS direction, that is, the direction of the composite vector C, and whose minor axis is in a direction orthogonal to this. The length of the major axis and the minor axis of the elliptical locus is determined by various parameters constituting the magnetic field, for example, the magnetic force of the segment magnets M1 to M40, the number of the segment magnets M1 to M40, and the segment magnets M1 to M4.
The magnetic field having a circular magnetic field line is formed by eliminating the non-uniformity between the NS direction and the direction (EW direction) of the magnetic field shown in FIG. It is set as follows.

The main part of the etching apparatus 1 according to the present embodiment is configured as described above. With the arrangement of the dipole ring magnet 41 as described above, when the wafer P is viewed from the side in the Y-axis direction. As shown in FIG. 4, when the dipole ring magnet 41 is stationary, a magnetic field substantially parallel to a plane including the wafer P is formed.

Similarly, when the dipole ring magnet 41 is stationary, that is, when the rotary stage 42 is stopped, as shown in FIG. 5, the magnetic field intensity distribution in the NS direction (curve a). And the magnetic field strength distribution (curve b) in the direction (E-W direction) orthogonal to the NS direction almost coincides. Then, as shown in FIG. 6 corresponding to FIG. 16, the lines connecting the equal strength positions of the magnetic field form concentric circles centered on the center of the wafer P as the substrate to be processed.

Next, using the etching apparatus 1 according to the present embodiment, for example, an oxide film (Si
The process, operation, and the like in the case of etching O ₂ ) will be described. A side surface of the etching apparatus 1 is a load lock chamber (see FIG. (Not shown) are arranged side by side, and when the wafer P, which is a substrate to be processed, is carried in and out of the processing container 3, the susceptor 6 is lowered to a predetermined transfer position by the operation of the drive source 8.

Then, the wafer P is carried into the processing chamber 2 from the load lock chamber (not shown), and is held at a predetermined position on the susceptor 6 by holding means such as an electrostatic chuck.
Is set. Next, the susceptor 6 is raised to a predetermined etching processing position (the position shown in FIG. 1) by the operation of the drive source 8. At the same time, the inside of the processing chamber 2 is evacuated by the evacuation means 12 to a predetermined degree of reduced pressure. After that, a predetermined processing gas, for example, CF ₄ is supplied from the processing gas supply source 27 at a predetermined flow rate, and the processing is performed. The pressure in the chamber 2 is set and maintained at a predetermined pressure reduction degree, for example, 20 mTorr.

Next, the frequency of the upper electrode 22 from the second high frequency power supply 34 is 27.12 MHz and the power is 2 k.
When the high frequency power of W is supplied, the etching gas in the processing chamber 2, that is, the gas molecules of the CF ₄ gas are dissociated and turned into plasma. At the same time, high-frequency power having a frequency of 800 kHz and power of 1 kW is supplied to the susceptor 6 from the first high-frequency power supply 31.

Further, when the rotating stage 42 is rotated by the operation of the driving means 43 and the dipole ring magnet 41 is rotated around the outer periphery of the processing container 3, a uniform magnetic field parallel to the wafer P, ie, the high frequency A parallel magnetic field is formed in a direction orthogonal to the electric field formed by the power supply.

As a result, electrons in the plasma cause an E × B drift motion, and as a result, further dissociation occurs due to collision with neutral molecules, so that the density of the plasma in the processing chamber 3 becomes extremely high. Also, for example, the diffusion of even electrons in the bulk that does not cause E × B drift motion is suppressed by the magnetic field. Therefore, the plasma density is also high from this point.

Under such a plasma atmosphere, high-density etchant ions generated by the plasma atmosphere are incident by a relatively low frequency high frequency (800 kHz) supplied from the first high frequency power supply 31 to the susceptor 6 side. While the energy is controlled independently of the plasma generation process, the silicon oxide film (SiO ₂ ) on the surface of the wafer P is etched. Therefore, it is possible to perform a predetermined etching process without damaging the wafer P. Further, an etching process with a high etching rate and high in-plane uniformity is performed on the wafer P.

In this etching apparatus 1,
As described above, in the dipole ring magnet 41,
Since the plurality of segment magnets M1 to M40 are arranged in an elliptical shape, the magnetic field formed in the processing chamber 2 is corrected,
As a result, the magnetic field in the processing chamber 2 becomes uniform from the surface to be processed, its outer peripheral edge, and at least the space above the surface to be processed where plasma is generated. Can be applied.

Further, since the segment magnets M1 to M40 are formed of the same member, even if the plasma processing apparatus is enlarged in accordance with the expected increase in the size of the substrate to be processed,
Since the same type of segment magnets M can be used, the production cost of the segment magnets M can be reduced.

Next, a second embodiment in which the present invention is applied to an etching apparatus will be described. In the following description, components having the same functions and configurations as those of the above-described embodiment will be denoted by the same reference numerals,
Duplicate description will be omitted.

FIG. 7 schematically shows a cross section of an etching apparatus 100 according to the second embodiment. A dipole ring magnet 101 is disposed on the outer periphery of the processing container 3 as a magnetic field generating means. As shown in FIG. 8, the dipole ring magnet 101 has 36 cylindrical segment magnets Mg1 to Mg36 arranged in an annular shape on an annular rotary stage 42. These segment magnets Mg1 to Mg36 have the same shape and the same size, but when arranged on the rotary stage 42, they are arranged so that their magnetization directions face different directions as described later.

Further, a shield ring 102 made of an annular magnetic material is provided on the rotary stage 42 so as to surround the outer circumference of the dipole ring magnet 101, and rotates in synchronization with the dipole ring magnet 101. .

As described above, each segment magnet Mg1
Since Mg36 has the same shape and size, the segment magnet Mg1 will be described, for example.
Is a columnar magnet material as a whole. For example, cylindrical magnet materials 103 and 104 of the same shape and the same size for magnetizing into a magnet
A non-magnetic body 105 made of, for example, an aluminum material having the same diameter is disposed between the two, and has a structure in which the non-magnetic body 105 is sandwiched.
Then, the thus configured material is magnetized and, for example, magnet materials 103, 10
By magnetizing No. 4, the segment magnet Mg1 is formed (the tip of the arrow A indicates the N pole). The magnetization directions of the magnet materials 103 and 104 are exactly the same.

As shown in FIG. 9, auxiliary magnets 106 and 107 made of, for example, permanent magnets having the same diameter are fixed to the upper end and the lower end of the segment magnet Mg1, respectively.
The directions of the magnetic fields of the auxiliary magnets 106 and 107 are directed toward the center along the vertical direction of the segment magnet Mg1, as indicated by arrows B1 and B2 in FIG. This makes it possible to reduce the vertical magnetic field component of the magnetic field formed by the segment magnet Mg.

Therefore, the vertical component of the magnetic field of the segment magnet Mg formed in the processing chamber 2 (arrow S in FIG. 9).
1, S2) is corrected by the magnetic field (arrows B1, B2 in the figure) formed by the auxiliary magnets 106, 107, and a uniform magnetic field is formed in the processing chamber 2.

Further, other segment magnets Mg2 to Mg36
Has exactly the same configuration as this segment magnet Mg1,
The above-mentioned auxiliary magnets 106 and 107 are provided at the upper end and the lower end, respectively.
Has been fixed. These segment magnets Mg1
The rotation of the dipole ring magnet 101 made of Mg36 is the same as that of the dipole ring magnet 41, and therefore, the description is omitted. The magnetic field vector C formed in the processing chamber 2 by the dipole ring magnet 101 is directed in the direction indicated by the thick arrow in FIG. 10 along the NS direction.

At a predetermined position in the outer peripheral direction of the shield ring 102, a counter magnet 108 as magnetic field generating means for preventing magnetic field leakage as shown in FIG. 8 is attached. The counter magnet 108 has a substantially rectangular parallelepiped shape as a whole, and is made by magnetizing a magnet material having the shape, for example, in the direction of the arrow in FIG.

In this embodiment, as shown in FIGS. 8 and 10,
Positions along the direction of the magnetic field vector C, that is, the segment magnets Mg35 to Mg2 and the segment magnets Mg
A total of 16 pieces are attached to the outer periphery of the shield ring 102 in two steps, upper and lower, so as to be located outside of 17 to Mg20. Therefore, the segment magnets Mg35 to Mg
2 side counter magnet group and segment magnet Mg17 ~
The Mg20-side counter magnets have a positional relationship facing each other along the direction of the magnetic field vector. Each counter magnet 10 when attached to the shield ring 102
For the magnetic poles of the eight groups, the segment magnets Mg35 to Mg
The two magnets are mounted such that the N pole is located outside, and the segment magnets Mg17 to Mg20 are located such that the N pole is located inside.

The main part of the etching apparatus 100 according to the second embodiment is configured as described above, and the vertical components of the magnetic field generated by the segment magnets Mg1 to Mg36 are appropriately corrected by the auxiliary magnets 106 and 107. Thus, the curved magnetic field having a vertically convex shape, which has conventionally occurred, can be corrected. Therefore, a magnetic field that is horizontal with respect to the wafer P, which is a substrate to be processed, is formed at least in the plasma generation space above the surface to be processed, its outer peripheral edge, and the surface to be processed. Plasma treatment can be performed.

The shield ring 10 provided in the device
With the 2 and the counter magnet 108, the leakage of the magnetic field generated from the dipole ring magnet 101 can be prevented, and the magnetic influence of peripheral devices can be prevented. That is, the magnetic field generated by the dipole ring magnet 101 tends to leak in all directions around the outer periphery of the processing container 3, but since the magnetic shield ring 102 is arranged on the outer periphery of the side surface of the dipole ring magnet 101, Leakage of the magnetic field to a nearby location is prevented. Moreover, a counter magnet 108 is further provided around the outer periphery of the shield ring 102.
Is disposed, magnetic field leakage to a distant place is also prevented.

Therefore, even if the same apparatus as the etching apparatus 100 is installed in a place close to each other, the desired high-speed and uniform etching processing can be performed without interference of the magnetic field. Further, since magnetic field leakage to a distant place is prevented, magnetic influence on peripheral devices can be prevented. In addition, since the shield ring 102 rotates together with the dipole ring magnet 101, even if the counter magnet 108 is attached to a part of the shield ring 102, it is possible to prevent the magnetic field from leaking over the entire circumference. Needless to say, the magnetic field leakage prevention means including the shield ring 102 and the counter magnet 108 can be implemented in the etching apparatus 1 according to the first embodiment.

As described in the above embodiments, the segment magnets M1 to M40, which are anisotropic segment magnets constituting the dipole ring magnets 41 and 101,
Since Mg1 to Mg36 have the same configuration,
We manufacture many segments of one type for each,
By changing the arrangement, the desired dipole ring magnet 4
1 or 101 can be configured. Therefore, it is possible to easily obtain an anisotropic segment magnet having a desired magnetization direction only by changing the arrangement state, and the manufacturing cost is low.

The electrons in the plasma cause an E × B drift motion and move from the E pole to the W pole, so that the plasma density of the W pole is higher than that of the E pole. Therefore, if the magnetic field intensity distribution considering the influence of the E × B drift motion is formed, the uniformity of the plasma density can be further improved. Specifically, FIGS. 12 and 13
As shown in FIGS. 12 and 13 (corresponding to FIGS. 15 and 16, respectively), if a gradient magnetic field gradually weakening from the E pole side to the W pole side is formed, E × B The effect of suppressing the diffusion of the electrons that has caused the drift motion is weakened. As a result, the concentration of the electrons on the W pole side is avoided, and the uniformity of the plasma density on the wafer is improved.

In order to form such a gradient magnetic field,
As shown in FIG. 14, the anisotropic segment magnets M1 to Mn forming the dipole ring magnet 201 are arranged in a substantially elliptical shape, and the center of the ellipse Z is shifted from the center of the wafer P toward the W pole. do it. Note that the magnetization directions of the anisotropic segment magnets M1 to Mn forming the dipole ring magnet 201 are set in the same manner as in the first and second embodiments by making a half turn around the wafer P. Return to the original direction, each of the anisotropic segment magnets M1 to Mn
Are set to be shifted from each other.

The dipole ring magnets 41 and 101 used in the above embodiment are respectively 40 segment magnets M1 to M40 and 36 segment magnets Mg1 to Mg
The number of the segment magnets may be arbitrarily selected as required. Therefore, for example, when the number of the segment magnets M1 to M40 provided in the dipole ring magnet 41 is reduced, that is, when thinning is performed, the major axis of the ellipse of the dipole ring magnet 41 is reduced while a desired magnetic field is generated in the processing chamber 2. The length of the etching apparatus can be reduced, and the size of the etching apparatus 1 can be reduced. Further, for example, the segment magnets Mg1 to Mg3 provided on the dipole ring magnet 101
When thinning is performed on 6, the fine adjustment of the magnetic field generated in the processing chamber 2 is further facilitated.

Although the above embodiment is an example in which the present invention is configured as an etching apparatus, the present invention is not limited to this, and the present invention can be embodied as another plasma processing apparatus such as an ashing apparatus, a sputtering apparatus, and a CVD apparatus. . Further, the substrate to be processed is not limited to the wafer, and may be an LCD substrate.

[0059]

According to the present invention, a dipole ring magnet having a plurality of anisotropic segment magnets arranged in an elliptical shape on the outer periphery of a processing vessel in a plasma processing apparatus, or a plurality of anisotropic segment magnets having an auxiliary magnet are provided. Is provided on the outer periphery of the processing container in a ring shape, so that the uniformity of the magnetic field formed in the processing container can be improved as compared with the related art. Therefore, a more uniform plasma processing can be performed on the substrate to be processed than before. Further, since each dipole ring magnet is formed by the same anisotropic segment magnet, even if the plasma processing apparatus is enlarged due to the increase in the size of the substrate to be processed, substantially the same anisotropic segment magnet is used. It can be used, and the production cost of the anisotropic segment magnet can be reduced. If a magnetic field generating means for preventing magnetic field leakage is provided on the outer periphery of the dipole ring magnet, it is possible to prevent the generation of a leakage magnetic field around the apparatus, prevent the magnetic influence of peripheral devices, and manufacture a multi-chamber type semiconductor device. In constructing the system, the degree of freedom of design and the uniformity of the magnetic field strength can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of an etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the magnetization direction of each segment magnet of the dipole ring magnet used in the etching apparatus in FIG.

FIG. 3 is a perspective view of a segment magnet used for the dipole ring magnet of FIG.

FIG. 4 is an explanatory diagram showing a state of a magnetic field in a processing chamber in the etching apparatus of FIG. 1 as viewed from a side.

FIG. 5 is an explanatory view showing a state of a magnetic field gradient on a wafer in the etching apparatus of FIG. 1 as viewed from a side.

FIG. 6 is an explanatory diagram viewed from a plane showing a state of a curve (equal intensity line) connecting equal intensity positions on a wafer in the etching apparatus of FIG. 1;

FIG. 7 is an explanatory sectional view of an etching apparatus according to a second embodiment of the present invention.

FIG. 8 is a perspective view of a dipole ring magnet used in the etching apparatus of FIG.

FIG. 9 is a perspective view of a segment magnet used for the dipole ring magnet of FIG. 7;

FIG. 10 is a plan view showing a magnetization direction of each segment magnet of the dipole ring magnet of FIG. 7;

FIG. 11 is a perspective view of a counter magnet attached to a shield ring of the dipole ring magnet of FIG.

FIG. 12 shows a magnetic field strength distribution when improving the uniformity of the plasma density in consideration of the E × B drift motion of electrons.
It is explanatory drawing from the wafer side surface.

FIG. 13 shows a magnetic field strength distribution when improving the uniformity of plasma density in consideration of the E × B drift motion of electrons.
It is explanatory drawing from a wafer plane.

FIG. 14 is an explanatory diagram showing an example of the arrangement of anisotropic segments for forming the magnetic field intensity distribution shown in FIGS.

FIG. 15 is an explanatory view showing a magnetic field intensity distribution according to a conventional technique, viewed from the side of a wafer.

FIG. 16 is an explanatory diagram showing a magnetic field intensity distribution according to a conventional technique, viewed from a wafer plane.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 100 Etching apparatus 2 Processing chamber 3 Processing container 6 Susceptor 12 Vacuum evacuation means 22 Upper electrode 27 Processing gas supply source 31 1st high frequency power supply 34 2nd high frequency power supply 41, 101 Dipole ring magnet 42 Rotation stage 102 Shield ring 106 , 107 Auxiliary magnet 108 Counter magnet M1 to M40, Mg1 to Mg36 Segment magnet P Wafer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomomi Kondo 5-3-6 Akasaka, Minato-ku, Tokyo Inside Tokyo Electron Co., Ltd. (72) Inventor Koji Miyata 2-5-1 Kitafu, Takefu City, Fukui Prefecture Shinetsu Kagaku Kogyo Co., Ltd.

Claims (6)

[Claims] An apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing predetermined processing on a substrate to be processed in the processing container, comprising: a plurality of anisotropic segment magnets; A plasma processing apparatus provided with a dipole ring magnet having an annular arrangement around the outer periphery of a processing container, wherein the arrangement of the anisotropic segment magnets is made elliptical. 2. An apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing predetermined processing on a substrate to be processed in the processing container, comprising: a plurality of anisotropic segment magnets; A dipole ring magnet arranged annularly around the outer periphery of the processing vessel, wherein at least one of the upper end and the lower end of the anisotropic segment magnet corrects a vertical component of a magnetic field in the processing vessel. A plasma processing apparatus comprising an auxiliary magnet. 3. An apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing predetermined processing on a substrate to be processed in the processing container, the apparatus comprising a plurality of anisotropic segment magnets. A plasma processing apparatus comprising a dipole ring magnet in which a plurality of anisotropic segment magnets are annularly arranged on the outer periphery of a processing container, wherein the plurality of anisotropic segment magnets are not arranged at equal intervals. 4. An apparatus for introducing a processing gas into a processing container, converting the processing gas into plasma, and performing a predetermined processing on a substrate to be processed in the processing container, the apparatus comprising a plurality of anisotropic segment magnets. In the plasma processing apparatus provided with a dipole ring magnet arranged in an annular shape on the outer periphery of the processing container, the arrangement of the anisotropic segment magnet is substantially elliptical, and the center of the substantially ellipse is from the center of the substrate to be processed. A plasma processing apparatus, wherein these anisotropic segment magnets are arranged so as to be eccentric in a direction along a major axis direction of an ellipse. 5. The distance between anisotropic segment magnets is
The side with the center of the ellipse is relatively sparse with respect to the minor axis of the ellipse,
The plasma processing apparatus according to claim 4, wherein the other side is set to be relatively dense. 6. A magnetic body is disposed on a side surface of the dipole ring magnet, and the magnetic body is further provided with a magnetic field generating means for preventing a magnetic field from leaking. 6. The plasma processing apparatus according to 4 or 5.