JP4379771B2 - Plasma processing apparatus and plasma processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus and a plasma processing method for performing plasma processing such as etching on a substrate to be processed such as a semiconductor wafer.
[0002]
[Prior art]
Conventionally, in the field of semiconductor device manufacturing, plasma is generated in a processing chamber, and this plasma is applied to a substrate to be processed such as a semiconductor wafer disposed in the processing chamber to perform predetermined processing such as etching or film formation. There is known a plasma processing apparatus for performing the above.
[0003]
In order to perform good processing in such a plasma processing apparatus, it is necessary to maintain the plasma state in a good state suitable for plasma processing. For this reason, a magnetic field for controlling plasma has conventionally been used. A plasma processing apparatus having a magnetic field forming mechanism to be formed is used.
[0004]
As a magnetic field forming mechanism, a substrate to be processed such as a semiconductor wafer disposed horizontally with a processing surface facing upward is arranged so that N and S magnetic poles are alternately adjacent to surround the periphery of the semiconductor substrate. A multi-pole type is known in which a magnetic field is not formed above a wafer, but a multi-pole magnetic field is formed so as to surround the periphery of the wafer. The number of poles of the multipole is an even number of 4 or more, and the number of poles is preferably selected between 8 and 32 so that the magnetic field strength around the wafer matches the processing conditions.
[0005]
[Problems to be solved by the invention]
In this way, plasma processing is performed in which a predetermined multipole magnetic field is formed around a substrate to be processed such as a semiconductor wafer in the processing chamber, and plasma processing such as etching processing is performed while controlling the plasma state by the multipole magnetic field. The apparatus is known. However, according to research by the present inventors, in plasma processing, for example, plasma etching, the in-plane uniformity of the etching rate is improved by performing plasma etching processing in a state where a multipole magnetic field is formed. On the contrary, it has been found that the in-plane uniformity of the etching rate may be improved by performing the plasma etching process in the absence of the multipole magnetic field.
[0006]
For example, when etching a silicon oxide film or the like, in-plane etching of the semiconductor wafer is performed by forming a multipole magnetic field compared to etching without forming a multipole magnetic field. The uniformity of the rate (etching rate) can be improved. That is, when etching is performed without forming a multipole magnetic field, the etching rate increases at the center of the semiconductor wafer and decreases at the periphery of the semiconductor wafer (nonuniform etching rate). ) Occurs.
[0007]
On the other hand, when etching organic low dielectric constant films (so-called Low-K) etc., etching without forming a multipole magnetic field forms a multipole magnetic field. The uniformity of the etching rate within the semiconductor wafer surface can be improved as compared with the case where the above is performed. That is, in this case, when etching is performed by forming a multipole magnetic field, the etching rate is lowered at the central portion of the semiconductor wafer and the etching rate is increased at the peripheral portion of the semiconductor wafer. Uniformity) occurs.
[0008]
Here, if the above-described magnetic field forming mechanism is composed of an electromagnet, control of formation and extinction of the magnetic field can be easily performed. However, the use of an electromagnet causes a problem of increased power consumption, so that in many devices, a permanent magnet is generally used. However, when a permanent magnet is used, control such as “forming” or “not forming” the magnetic field requires that the magnetic field forming means itself be attached to or removed from the device. For this reason, there is a problem that a large apparatus is required for attaching and detaching the magnetic field forming means, and there is a problem that it takes a long time for the work, and accordingly, there is a problem that the work efficiency of the entire semiconductor processing is lowered.
[0009]
The present invention has been made to solve such a conventional problem, and can be controlled and set to an appropriate multipole magnetic field state according to the type of plasma processing process. It is an object of the present invention to provide a plasma processing apparatus that can be performed easily and easily.
[0010]
[Means for Solving the Problems]
The present invention provides a processing chamber that accommodates a substrate to be processed, a mechanism that is provided in the processing chamber and generates plasma for performing a predetermined plasma process on the substrate to be processed, and is provided outside the processing chamber and performs the processing. The present invention relates to a plasma processing apparatus having a magnetic field forming mechanism for forming a predetermined multipole magnetic field around the substrate to be processed in a room, wherein the magnetic field forming mechanism is rotatably provided and a first magnet capable of changing a magnetic field direction. A plasma processing apparatus comprising: a segment; and a second magnet segment which is provided adjacent to the first magnet segment and has a magnetization in a circumferential direction with respect to a center of the processing chamber, and is fixed.
[0011]
The present invention provides a processing chamber that accommodates a substrate to be processed, a mechanism that is provided in the processing chamber and generates plasma for performing a predetermined plasma process on the substrate to be processed, and is provided outside the processing chamber and performs the processing. The present invention relates to a plasma processing apparatus having a magnetic field forming mechanism for forming a predetermined multipole magnetic field around the substrate to be processed in a room, wherein the magnetic field forming mechanism is rotatably provided and a first magnet capable of changing a magnetic field direction. A plasma processing apparatus comprising: a segment; and a second magnet segment which is provided adjacent to the first magnet segment and has a magnetization in a radial direction with respect to a center of the processing chamber.
[0012]
The first and second magnet segments are arranged in a ring shape, and the first and second magnet segments arranged in the ring shape are surrounded by a magnetic ring on the outside thereof.
[0013]
Further, the magnetic field forming mechanism may have an upper magnetic field forming mechanism and a lower magnetic field forming mechanism which are provided separately in a vertical direction, and the upper magnetic field forming mechanism and the lower magnetic field forming mechanism are close to each other. However, it is configured to be movable in the vertical direction so that it can be kept away.
[0014]
Furthermore, a state in which a predetermined multipole magnetic field is formed around the substrate to be processed in the processing chamber by rotating the first magnet segment, and a multipole around the substrate to be processed in the processing chamber is formed. It can be set to a state in which a magnetic field is not formed. Furthermore, it is preferable that each of the first and second magnet segments has a substantially cylindrical shape.
[0015]
Furthermore, the present invention is characterized in that plasma is applied to the substrate to be processed to perform an etching process.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 schematically shows a configuration when an embodiment according to the present invention is applied to a plasma etching apparatus for etching a semiconductor wafer. In the figure, reference numeral 1 denotes a cylindrical vacuum chamber made of aluminum, for example, and constitutes a plasma processing chamber. The vacuum chamber 1 has a stepped cylindrical shape composed of a small-diameter upper portion 1a and a large-diameter lower portion 1b, and is connected to a ground potential. A support table (susceptor) 2 is provided inside the vacuum chamber 1 to support a semiconductor wafer W as a substrate to be processed substantially horizontally with its surface to be processed facing upward.
[0018]
The support table 2 is made of a material such as aluminum, and is supported by a conductor support 4 via an insulating plate 3 made of ceramic or the like. A focus ring 5 made of a conductive material or an insulating material is provided on the outer periphery above the support table 2.
[0019]
An electrostatic chuck 6 for electrostatically attracting the semiconductor wafer W is provided on the mounting surface of the semiconductor wafer W of the support table 2. The electrostatic chuck 6 is configured by disposing an electrode 6a between insulators 6b, and a DC power source 13 is connected to the electrode 6a. By applying a voltage from the power source 13 to the electrode 6a, the semiconductor wafer W is attracted to the support table 2 by Coulomb force.
[0020]
Furthermore, a coolant channel (not shown) for circulating the coolant is supplied to the support table 2 and He gas is supplied to the back surface of the semiconductor wafer W in order to efficiently transfer the cold heat from the coolant to the semiconductor wafer W. A gas introduction mechanism (not shown) is provided so that the semiconductor wafer W can be controlled to a desired temperature.
[0021]
The support table 2 and the support table 4 can be moved up and down by a pole screw mechanism including a ball screw 7, and a drive portion below the support table 4 is covered with a bellows 8 made of stainless steel (SUS). A bellows cover 9 is provided on the outside.
[0022]
A power supply line 12 for supplying high-frequency power is connected to substantially the center of the support table 2. A matching box 11 and a high frequency power source 10 are connected to the feeder line 12. From the high frequency power supply 10, high frequency power in the range of 13.56 to 150 MHz (preferably 13.56 to 100 MHz), for example, 100 MHz, is supplied to the support table 2.
[0023]
In order to increase the etching rate, it is preferable to superimpose a high frequency for plasma generation and a high frequency for drawing ions in the plasma, and a high frequency power source (not shown) for ion drawing (bias voltage control). In this case, those having a frequency in the range of 500 KHz to 13.56 MHz are used. This frequency is preferably 3.2 MHz when the etching target is a silicon oxide film, and 13.56 MHz when a polysilicon film or an organic material film is used.
[0024]
Further, a baffle plate 14 is provided outside the focus ring 5. The baffle plate 14 is electrically connected to the vacuum chamber 1 through the support 4 and the bellows 8. On the other hand, a shower head 16 is provided on the top wall portion of the vacuum chamber 1 above the support table 2 so as to face the support table 2 in parallel, and the shower head 16 is grounded. Accordingly, the support table 2 and the shower head 16 function as a pair of electrodes.
[0025]
A large number of gas discharge holes 18 are provided in the shower head 16, and a gas introduction part 16 a is provided above the shower head 16. A gas diffusion gap 17 is formed between the shower head 16 and the top wall of the vacuum chamber 1. A gas supply pipe 15a is connected to the gas introduction part 16a, and a processing gas supply system 15 for supplying a processing gas composed of a reactive gas for etching and a dilution gas is connected to the other end of the gas supply pipe 15a. is doing.
[0026]
As the reaction gas, for example, a halogen-based gas (fluorine-based or chlorine-based), hydrogen gas, or the like can be used. As the dilution gas, a gas usually used in this field such as Ar gas, He gas, or the like is used. Can do. Such a processing gas reaches the gas diffusion gap 17 above the shower head 16 from the processing gas supply system 15 through the gas supply pipe 15a and the gas introduction portion 16a, and is discharged from the gas discharge hole 18 to the semiconductor wafer W. The film is supplied to the formed film for etching.
[0027]
An exhaust port 19 is formed on the side wall of the lower portion 1 b of the vacuum chamber 1, and an exhaust system 20 is connected to the exhaust port 19. By operating a vacuum pump provided in the exhaust system 20, the inside of the vacuum chamber 1 can be depressurized to a predetermined degree of vacuum. Further, a gate valve 24 that opens and closes the loading / unloading port of the semiconductor wafer W is provided on the upper side wall of the lower portion 1 b of the vacuum chamber 1.
[0028]
On the other hand, an annular magnetic field forming mechanism (ring magnet) 21 is disposed concentrically with the vacuum chamber 1 around the outside of the upper portion 1 a of the vacuum chamber 1, and a processing space between the support table 2 and the shower head 16. A magnetic field is formed around the. The entire magnetic field forming mechanism 21 can be rotated around the vacuum chamber 1 at a predetermined rotational speed by a rotating mechanism 25.
[0029]
As shown in FIG. 2, the magnetic field forming mechanism 21 includes a plurality (32 in FIG. 2) of magnet segments 22a (first magnet segments) and 22b (second magnets) supported by a support member (not shown). Segment) is the main component. The plurality of magnet segments 22a are arranged every other magnet segment 22b so that the magnetic poles facing the vacuum chamber 1 side are S, N, S, N,. Similarly, the magnet segments 22b are alternately arranged with respect to the magnet segment 22a, and the magnetic field direction is arranged to be opposite to the circumferential magnetic field formed in the vacuum chamber 1. The tip of the arrow in the figure indicates the N pole. Furthermore, it is preferable that the outer circumferences of the magnet segments 22 a and 22 b are surrounded by the magnetic body 23. In the following description, the magnet segments 22a and 22b may be collectively indicated by the reference numeral 22.
[0030]
In the state shown in FIG. 2, the direction of the magnetic poles of the magnet segments 22a arranged alternately with respect to the magnet segment 22b is opposite to each other in the radial direction, while the direction of the magnetic poles of the magnet segment 22b therebetween is a magnetic field. The direction of the magnetic field formed in the circumferential direction of the forming mechanism 21 is fixed in a substantially opposite direction. Therefore, in the vacuum chamber 1, magnetic field lines as shown in the figure are formed between the magnet segments 22a of the magnetization in the radial direction arranged every other magnet segment 22b, and the periphery of the processing space, that is, the vacuum chamber 1 is formed. A magnetic field of, for example, 0.02 to 0.2 T (200 to 2000 G), preferably 0.03 to 0.045 T (300 to 450 G) is formed in the vicinity of the inner wall of the semiconductor wafer W. Multi-pole magnetic field is formed so that
[0031]
The reason why the magnetic field strength range is defined in this manner is that if the magnetic field strength is too strong, magnetic flux leaks, and if it is too weak, the effect of plasma confinement cannot be obtained. Therefore, such a numerical value is an example determined by the structure (material) of the apparatus, and is not necessarily limited to this numerical range.
[0032]
In addition, it is desirable that the substantially no magnetic field in the central portion of the semiconductor wafer W described above is originally zero T (Tesla), but a magnetic field that affects the etching process is not formed in the arrangement portion of the semiconductor wafer W. Any value that does not substantially affect the wafer processing may be used. In the state shown in FIG. 2, a magnetic field having a magnetic flux density of 420 μT (4.2 G) or less, for example, is applied to the periphery of the wafer, thereby exhibiting the function of confining plasma.
[0033]
Further, in the present embodiment, each magnet segment 22a (or 22c in FIG. 4) of the magnetic field forming mechanism 21 is rotatable around the vertical central axis of the segment in the magnetic field forming mechanism 21 by the magnet segment rotating mechanism. It is said that. Each magnet segment 22b (or 22d in FIG. 4) of the magnetic field forming mechanism 21 is fixed and does not rotate.
[0034]
That is, as shown in FIGS. 2 and 3 (a), from the state in which the magnetic pole of each magnet segment 22a faces the vacuum chamber 1 side, as shown in FIGS. 3 (b) and 3 (c), the magnet segment Every other magnet segment 22a is configured to rotate in the same direction in synchronization with 22b. 3B shows a state in which the magnet segment 22a is rotated 45 degrees from the state of FIG. 3A, and FIG. 3C shows that the magnet segment 22a is 90 ° from the state of FIG. It shows a state rotated by a degree. In particular, in the case of FIGS. 2 and 3, the rotation of the magnet segment 22a is intended to be a rotation greater than 0 degree and 90 degrees (until the magnetic pole faces the circumferential direction).
[0035]
Further, as shown in FIGS. 2 and 4 (a), the magnet segments 22c are arranged alternately with respect to the magnet segment 22d, and the magnet segments 22c are rotated in synchronism with each other so that the magnetic poles are in a vacuum chamber. It can also be configured so as to face in the radial direction, as shown in FIGS. 4B shows a state in which the magnet segment 22c is rotated 90 degrees from the state of FIG. 4A, and FIG. 4C shows that the magnet segment 22c is 180 degrees from the state of FIG. 4A. It shows a state rotated by a degree. In particular, in the case of FIG. 2 and FIG. 4, the rotation of the magnet segment 22 c is intended to be a rotation greater than 0 degree and 180 degrees (until the magnetic pole faces the radial direction).
[0036]
5, the vertical axis represents the magnetic field strength, and the horizontal axis represents the distance from the center of the semiconductor wafer W disposed in the vacuum chamber 1. As shown in FIG. 1 (curve A), a state where each magnet segment 22a is rotated by 45 degrees as shown in FIG. 3B (curve B), and 90% of each magnet segment 22a as shown in FIG. 3C. The relationship between the distance from the center of the semiconductor wafer W and the magnetic field strength in a state rotated by a degree (curve C) is shown. The D / S inner diameter shown in the figure indicates the inner diameter of the deposit shield for protecting the inner wall provided on the inner wall of the vacuum chamber 1, and substantially indicates the inner diameter of the vacuum chamber 1 (processing chamber). Yes.
[0037]
As shown by a curve A in FIG. 5, in a state where the magnetic poles of the magnet segments 22a face the vacuum chamber 1, the multipole magnetic field is formed substantially to the peripheral edge of the semiconductor wafer W, while the curve C As shown by the above, in the state where each magnet segment 22a is rotated 90 degrees, the magnetic field strength is substantially zero (the magnetic field is weakened) in the vacuum chamber 1. Furthermore, as shown by the curve B, when the magnet segment 22a is rotated 45 degrees, the state is intermediate to the above state.
[0038]
Thus, in this Embodiment, each magnet segment 22a which comprises the magnetic field formation mechanism 21 is the same direction, and can rotate synchronously. Then, by such rotation of the magnet segment 22a, the multipole magnetic field is substantially formed around the semiconductor wafer W in the vacuum chamber 1 and substantially around the semiconductor wafer W in the vacuum chamber 1. The multi-pole magnetic field can be set to a state where no multi-pole magnetic field is formed.
[0039]
Therefore, for example, when etching the above-described silicon oxide film or the like, etching is performed by forming a multipole magnetic field around the semiconductor wafer W in the vacuum chamber 1, whereby the etching rate within the surface of the semiconductor wafer W is increased. Can improve the uniformity. On the other hand, when the above-described organic low dielectric constant film (Low-K) or the like is etched, the etching is performed without forming a multipole magnetic field around the semiconductor wafer W in the vacuum chamber 1. The uniformity of the etching rate in the W plane can be improved.
[0040]
6 to 8 show the results of examining the uniformity of the etching rate in the surface of the semiconductor wafer W, where the vertical axis is the etching rate (etching rate) and the horizontal axis is the distance from the center of the semiconductor wafer. In each of FIGS. 6 to 8, the curve A indicates a case where a multipole magnetic field is not formed in the vacuum chamber 1, and the curve B indicates a curve C when a multipole magnetic field of 0.03 T (300 G) is formed in the vacuum chamber 1. Shows a case where a multipole magnetic field of 0.08 T (800 G) is formed in the vacuum chamber 1.
[0041]
6 shows a case where a silicon oxide film is etched with C ₄ F ₈ gas, FIG. 7 shows a case where a silicon oxide film is etched with CF ₄ gas, and FIG. 8 shows an organic low dielectric constant with a mixed gas containing N ₂ and H _2. The case where the film (Low-K) is etched is shown. As shown in FIGS. 6 and 7, when the silicon oxide film is etched with a gas containing C and F such as C ₄ F ₈ or CF ₄ gas, the etching is performed with a multipole magnetic field formed in the vacuum chamber 1. It can be seen that the in-plane uniformity of the etching rate can be improved by performing the above. Further, as shown in FIG. 8, when an organic low dielectric constant film (Low-K) is etched with a mixed gas containing N ₂ and H ₂ , etching is performed without forming a multipole magnetic field in the vacuum chamber 1. It can be seen that the in-plane uniformity of the etching rate can be improved by performing the above.
[0042]
As described above, in the present embodiment, the state of the multipole magnetic field in the vacuum chamber 1 can be easily controlled by rotating the magnet segment 22a. Good processing can be performed in the state.
[0043]
Needless to say, the number of magnet segments 22a and 22b is not limited to 32 as shown in FIG. Moreover, the cross-sectional shape is not limited to the cylindrical shape shown in FIG. 2, and may be a square, a polygon, or the like. However, since the magnet segment 22a is rotated, the cross-section of the magnet segment 22a (and 22b) can be used to reduce the size of the apparatus by effectively using the installation space of the magnet segment 22a as shown in FIG. The shape is preferably circular and cylindrical.
[0044]
Furthermore, the magnet material which comprises the magnet segments 22a and 22b is not specifically limited, For example, it is possible to use well-known magnet materials, such as a rare earth magnet, a ferrite magnet, and an alnico magnet.
[0045]
A second embodiment will be described with reference to FIG. In the first embodiment shown in FIGS. 2 to 4, the total number of magnet segments 22 is 32, a 16-pole magnetic field is formed, and magnet segments 22a arranged every other magnet segment 22b are the same. It was rotating in sync with the direction. On the other hand, in the second embodiment, the total number of magnet segments 22 is 48, of which 32 are rotatable magnet segments 22a and 16 fixed magnet segments 22b are 16 poles. Is forming. That is, except for the total number of the magnet segments 22 constituting the magnetic circuit, it is substantially the same as the first embodiment described in FIG. Therefore, the arrangement of the first magnet segment and the second magnet segment may be appropriately arranged depending on the strength of the magnetic field to be obtained. However, the first magnet segment and the second magnet segment are partially arranged adjacent to each other and partially. An arrangement method such as arranging the second magnet segments at equal intervals is also conceivable.
[0046]
According to the second embodiment, a magnetic field zero state can be created from a multipole state by rotating the magnet segment 22a synchronously as shown by the white arrow in FIG. When the total number of magnet segments is increased in this way, the magnetic field strength at the wafer peripheral portion when rotated 90 degrees as compared with the first embodiment can be made closer to zero.
[0047]
By the way, as in the comparative example shown in FIG. 10, even if all the magnet segments 22 of the magnetic field forming mechanism are rotated in the direction of the white arrow, the magnetic field inside the chamber can be made zero from the multipole. However, in contrast to this comparative example, the present invention can reduce the number of rotating magnet segments, so that the apparatus can be simplified. Furthermore, since the magnetic efficiency of the embodiment according to the present invention is higher, the magnetic field strength at the chamber position in the multipole state can be increased by about 20% compared to the comparative example. In other words, it is possible to obtain the same magnetic field strength with a small amount of magnets.
[0048]
Further, the effect of the magnetic ring 23 will be described with reference to FIG. The magnetic ring 23 is preferably formed on the outer periphery of the magnet segment described above. Examples of the magnetic material include pure iron, carbon steel, iron-cobalt steel, and stainless steel. In the multi-pole state, magnetic flux flows in the multipole state so as to increase the magnetic field of the chamber portion, and in the state where the magnetic field is zero by rotating the magnet segment, the magnetic flux flows so as to weaken the magnetic field in the chamber portion. There is an effect that a wide range can be taken.
[0049]
Next, processing in the plasma etching apparatus configured as described above will be described.
[0050]
First, the gate valve 24 is opened, and the semiconductor wafer W is loaded into the vacuum chamber 1 by a transfer mechanism (both not shown) through a load lock chamber disposed adjacent to the gate valve 24, and is previously set in a predetermined position. Is placed on the support table 2 that has been lowered. Next, when a predetermined voltage is applied from the DC power supply 13 to the electrode 6a of the electrostatic chuck 6, the semiconductor wafer W is attracted to the support table 2 by Coulomb force.
[0051]
Thereafter, after the transfer mechanism is retracted to the outside of the vacuum chamber 1, the gate valve 24 is closed to raise the support table 2 to the position shown in FIG. 1, and the vacuum chamber is exhausted via the exhaust port 19 by the vacuum pump of the exhaust system 20. 1 is exhausted.
[0052]
After the inside of the vacuum chamber 1 reaches a predetermined degree of vacuum, a predetermined processing gas is introduced into the vacuum chamber 1 from the processing gas supply system 15 at a flow rate of, for example, 100 to 1000 sccm, and the inside of the vacuum chamber 1 has a predetermined pressure. For example, 1.33 to 133 Pa (10 to 1000 mTorr), preferably 2.67 to 26.7 Pa (20 to 200 mTorr).
[0053]
In this state, a high frequency power having a frequency of 13.56 to 150 MHz, for example, 100 MHz and a power of 100 to 3000 W is supplied from the high frequency power supply 10 to the support table 2. In this case, by applying high frequency power to the support table 2 that is the lower electrode as described above, a high frequency electric field is generated in the processing space between the shower head 16 that is the upper electrode and the support table 2 that is the lower electrode. As a result, the processing gas supplied to the processing space is turned into plasma, and a predetermined film on the semiconductor wafer W is etched by the plasma.
[0054]
At this time, as described above, depending on the type of plasma processing process to be performed, each magnet segment 22a is set in a predetermined direction in advance, and a multipole magnetic field having a predetermined strength is formed in the vacuum chamber 1, or It is set in a state where a multipole magnetic field is not substantially formed in the vacuum chamber 1.
[0055]
When a multipole magnetic field is formed, there is a possibility that a portion corresponding to the magnetic pole of the side wall portion (depot shield) of the vacuum chamber 1 (for example, a portion indicated by P in FIG. 2) is locally scraped. On the other hand, since the magnetic field forming mechanism 21 is rotated around the vacuum chamber 1 by the rotating mechanism 25 having a driving source such as a motor, the magnetic pole moves with respect to the wall portion of the vacuum chamber 1. It is possible to prevent the wall portion of the chamber 1 from being locally cut.
[0056]
When a predetermined etching process is performed, the supply of high-frequency power from the high-frequency power supply 10 is stopped, the etching process is stopped, and then the semiconductor wafer W is unloaded from the vacuum chamber 1 in the reverse procedure to the above-described procedure.
[0057]
In the embodiment described above, at least a part of the magnet segment 22 is configured to be rotatable in a horizontal plane around the vertical rotation axis, and the magnetic pole direction is changed to control the multipole magnetic field. Explained. Hereinafter, another embodiment of the control mechanism for the multipole magnetic field will be described. Also in this embodiment, the point that the multipole magnetic field is controlled by rotating the magnet segment 22a (and 22a ') is the same as in the above-described embodiment.
[0058]
Furthermore, as shown in FIG. 12, in this embodiment, the ring-shaped magnetic field forming mechanism may be divided into upper and lower parts and configured by an upper magnetic field forming mechanism and a lower magnetic field forming mechanism. The magnet segment 22a provided on the lower magnetic field forming mechanism and the magnet segment 22a ′ provided on the lower magnetic field forming mechanism are configured to be movable in the vertical direction so that they can be moved closer to and away from each other. In the case of such a configuration, when the magnet segment 22a and the magnet segment 22a ′ are brought close to each other, the magnetic field strength increases as shown by the arrow in FIG. 12 (a), while the magnet segment 22a and the magnet segment 22a. When separated from ′, the magnetic field strength decreases as shown by the arrow in FIG. Further, the second magnet segment 22b is arranged in the same manner as 22a. The second magnet segment 22b (and 22b ′) is not shown in FIG. 12, but the arrangement and the like can be easily understood from the above-described embodiment. With such a configuration, the multipole magnetic field in the vacuum chamber 1 may be controlled. Even in this configuration, it is preferable that the entire ring-shaped magnetic field forming mechanism 21 is rotated around the vacuum chamber 1 at a predetermined rotation speed by the rotation mechanism 25 shown in FIG. .
[0059]
In the above-described embodiment, the case where the present invention is applied to an etching apparatus for etching a semiconductor wafer has been described. However, the present invention is not limited to such a case. For example, the present invention can be applied to an apparatus for processing a substrate other than a semiconductor wafer, and can also be applied to a film processing apparatus such as plasma processing other than etching, for example, CVD.
[0060]
【The invention's effect】
As described above, according to the present invention, the state of an appropriate multipole magnetic field can be easily controlled and set according to the type of plasma processing process, and good plasma processing can be easily performed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of a plasma processing apparatus to which an embodiment of the present invention is applied.
FIG. 2 is a schematic diagram showing an outline of an example of a magnetic field forming mechanism used in the apparatus of FIG.
3 is a view for explaining a rotation operation of a magnet segment constituting the magnetic field forming mechanism of FIG. 2; FIG.
4 is a view for explaining a rotation operation of a magnet segment constituting the magnetic field forming mechanism of FIG. 2; FIG.
5 is a view showing a state of magnetic field strength in a vacuum chamber constituting the apparatus shown in FIG.
FIG. 6 is a view showing an example of the relationship between the in-plane distribution of the semiconductor wafer at the etching rate and the magnetic field according to the embodiment of the present invention.
FIG. 7 is a view showing an example of the relationship between the in-plane distribution of the semiconductor wafer at the etching rate and the magnetic field according to the embodiment of the present invention.
FIG. 8 is a view showing an example of the relationship between the in-plane distribution of the semiconductor wafer at the etching rate and the magnetic field according to the embodiment of the present invention.
FIG. 9 is a diagram showing an outline of another embodiment of a magnetic field forming mechanism used in the apparatus shown in FIG. 1;
FIG. 10 is a diagram showing a magnetic field formation mechanism (comparative example) for comparison with the magnetic field formation mechanism of the embodiment of the present invention.
FIG. 11 is a diagram showing the effect of a magnetic ring used in the magnetic field forming mechanism according to the embodiment of the present invention.
FIG. 12 is a view showing still another embodiment of the magnetic field forming mechanism according to the present invention.
[Sharpness of sign]
DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, 2 ... Support table, 3 ... Insulating plate, 4 ... Support stand, 5 ... Focus ring, 6 ... Electrostatic chuck, 7 ... Ball screw, 8 ... Bellows, 9 ... Bellows cover, 10 ... High frequency power supply DESCRIPTION OF SYMBOLS 11 ... Matching box, 12 ... Feed line, 13 ... DC power supply, 14 ... Baffle plate, 15 ... Process gas supply system, 16 ... Shower head, 17 ... Gas diffusion space, 18 ... Gas discharge hole, 19 ... Exhaust port 20 ... exhaust system, 21 ... magnetic field forming mechanism, 22 ... magnet segment, 23 ... magnetic body ring, 24 ... gate valve, 25 ... rotating mechanism

Claims (7)

A processing chamber that accommodates a substrate to be processed; a mechanism that is provided in the processing chamber to generate plasma for performing a predetermined plasma treatment on the substrate to be processed; and a target chamber that is provided outside the processing chamber and is in the processing chamber. A plasma processing apparatus having a magnetic field forming mechanism for forming a predetermined multipole magnetic field around a processing substrate, wherein the magnetic field forming mechanism includes a plurality of first magnet segments and a plurality of second magnets arranged in a ring shape. It has a magnet segment, the first and second magnet segments are arranged alternately, the first of each of the magnet segments field direction provided rotatably to and the same direction about synchronize its vertical axis The plasma processing apparatus is characterized in that each of the second magnet segments is fixed with a circumferential or radial magnetization with respect to the center of the processing chamber. A processing chamber that accommodates a substrate to be processed; a mechanism that is provided in the processing chamber to generate plasma for performing a predetermined plasma treatment on the substrate to be processed; and a target chamber that is provided outside the processing chamber and is in the processing chamber. A plasma processing apparatus having a magnetic field forming mechanism for forming a predetermined multipole magnetic field around a processing substrate, wherein the magnetic field forming mechanism includes a plurality of first magnet segments, a plurality of second magnet segments, and a plurality of magnets. Having a third magnet segment and ringing the plurality of first magnet segments, the plurality of second magnet segments and the plurality of third magnet segments in the order of the first, second and third magnet segments placed Jo, each of the first and second magnet segments are changeable magnetic field direction is provided rotatably in opposite directions a and synchronously about its vertical axis, the third magnet The plasma processing apparatus segment each is characterized in that it is has a fixed magnetization in the circumferential direction with respect to the center of the processing chamber. 3. The plasma processing apparatus according to claim 1, wherein the magnet segments arranged in a ring shape are surrounded by a magnetic ring on the outside thereof. The plasma processing apparatus according to any one of claims 1 to 3, wherein the magnetic field forming mechanism includes an upper magnetic field forming mechanism and a lower magnetic field forming mechanism which are provided separately in a vertical direction, and these upper magnetic field forming mechanisms are provided. A plasma processing apparatus, wherein the mechanism and the lower magnetic field forming mechanism are configured to be movable in the vertical direction so as to approach or move away from each other. 5. The plasma processing apparatus according to claim 1, wherein a rotation of a magnet segment forms a predetermined multipole magnetic field around the substrate to be processed in the processing chamber, and the substrate to be processed in the processing chamber. A plasma processing apparatus characterized in that it can be set to a state in which a multipole magnetic field is not formed around a processing substrate. 6. The plasma processing apparatus according to claim 1, wherein the magnet segment is substantially cylindrical. 7. A plasma processing method using the plasma processing apparatus according to claim 1, wherein plasma is applied to the substrate to be processed to perform an etching process.

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