JP2003318165A - Magnet arrangement making point-cusp magnetic field for plasma generation and plasma processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide magnet arrangement making point-cusp magnetic field for plasma generation that can produce uniform plasma distribution over the whole surface of a wafer so that a uniform processing speed may be realized, and to provide a plasma processing system. <P>SOLUTION: The magnet arrangement is used in the plasma processing system having a top electrode 1 placed above a surface of the wafer 23 and an outer insulating member 3 for supporting the electrode 1. The magnet arrangement is composed of a plurality of magnets 6 separately arranged on the outer surface of the electrode 1 and a plurality of magnets 6 separately arranged on the region corresponding to the outer surface of the insulating member 3. The magnets connected with the electrode 1 and the magnets connected with the insulating member 3 are arranged to satisfy a positional and magnetic relationship creating the predetermined magnet arrangement. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet array for producing a point cusp magnetic field for plasma generation. The magnet array is used in a plasma processing apparatus for manufacturing a semiconductor device on a silicon substrate or another substrate. The point cusp field magnet arrangement can improve process uniformity at the surface of the substrate or wafer to be processed.

[0002]

Plasma assisted wafer processing is a well established process in the manufacture of semiconductor devices, commonly referred to as integrated circuits. Conventionally, there are many different plasma-assisted processes such as etching, sputter deposition, chemical vapor deposition, for example. All of these processes must be performed to create a uniform processing rate such as the etch rate or the deposition rate on the wafer surface. If uneven processing rates occur on the wafer surface, many defective semiconductor devices are created.

Magnetically enhanced capacitively coupled plasmas have found wide application in wafer manufacturing processes due to their higher utilization efficiency of rf power (high frequency power). However, the majority of magnetically enhanced capacitively coupled plasmas create a non-uniform plasma over the entire surface of the wafer. This is because the electrons and ions in the plasma undergo an E × B drift, where E and B are the strength of the DC (direct current) electric field and magnetic field on the rf electrode surface, respectively. Due to this E × B drift, the plasma moves toward one side of the reaction vessel. Moreover, the magnetic field applied to the rf electrode in most of the magnetically enhanced plasma extends to the wafer surface. This presents another serious problem as the magnetic field prohibits the application of other rf electrodes applied to the wafer holder. The reason for this is again
That is, the plasma is moved to one side of the reaction vessel by the E × B drift. The movement of the plasma to one side creates a non-uniform plasma over the surface of the wafer. Therefore, most applications of magnetically enhanced plasmas are limited.

As a solution to the above-mentioned problems, an rf electrode having a plurality of magnets for producing a point cusp magnetic field under the electrode has been proposed. The point cusp magnetic field is limited near the rf electrode. The configuration or arrangement of magnets creates a strong magnetic field on the surface of the rf electrode and creates a magnetic field free environment on the surface of the wafer. This magnetic field does not cause the movement of plasma toward one side of the reaction vessel due to the E × B drift of electrons and ions. The reason is that the E × B drift is confined to a localized area and any of the neighboring drifts are in the opposite direction. Therefore, the E × B drift does not spread over a large area of the surface of the rf electrode.

However, the aforementioned rf electrode having a point-cusp magnetic field based on a given magnet arrangement can also create a non-uniform plasma across the surface of the wafer under some circumstances. This state is shown in FIG.
This will be described in detail with reference to FIG.

FIG. 8 shows a sectional view of a conventional plasma processing apparatus. The apparatus has a reaction vessel 100 and a wafer holder 201 inside it. The wafer holder 201 is arranged on the bottom wall 115. Wafer holder 21
0 is composed of an rf lower electrode 102 and an insulator 104. rf
The lower electrode 102 is arranged on the upper surface of the insulator 104. The lower electrode 102 is electrically insulated from the reaction container 100. The wafer 130 is mounted on the lower electrode 102.

Further, the reaction container 100 has an upper electrode 101 above the wafer holder 201. Upper electrode 10
1 has a disk shape, and is further supported by a ring-shaped insulator 103 fixed to the inner surface of the reaction container 100. In this structure, the upper electrode 101 is connected to the reaction vessel 100.
Electrically isolated from the rest of the. The plurality of magnets 106 are arranged on the upper surface of the upper electrode 101. Many magnets 106 are located in a circular area on the top surface. The magnets 106 are arranged in a form orthogonal to each other along a line perpendicular to the upper surface, so that the polarities of the magnets 106 facing the inside of the reaction vessel 100 are opposite to those of the adjacent magnets 106 on a straight line (side portion). And is the same as the diagonally adjacent magnets. These magnets generate a magnetic field having a closed magnetic flux 107 near the inner surface of the upper electrode 101. There are many closed magnetic fluxes 107 on the upper surface side and the lower surface side of the upper electrode 101.

The upper electrode 101 is supplied with an rf current from an rf power source 113 via a matching circuit 108. This r
The frequency of the f-current is typically in the range 10-150 MHz. Further, the lower electrode 102 may or may not be supplied with the rf current from the rf power source 112 via the matching circuit 111. If rf current is lower electrode 1
02, the frequency of the rf current is usually below 20 MHz.

Process gas is supplied into the reaction vessel 100 through a plurality of inlets 109, and the reaction vessel 100 is exhausted through a gas outlet 110. When an rf current is applied to the upper electrode 101 under an appropriately low pressure, for example, a low pressure of 1 to 20 Pa, plasma is generated by the capacitive coupling mechanism. This generated plasma is then forced to be confined by the closed magnetic flux 107.

Further, the reaction vessel 100 has a ceiling wall 114 and a cylindrical side wall 105. The reaction vessel is made to have an airtight structure.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The problems associated with the configuration of are described below. The magnet arrangement described above produces a large number of point cusp magnetic fields 107 on the lower surface of the upper electrode 101. The magnetic arrangement is
It is uniform on the upper surface of the upper electrode 101 except for the edge portion. Each magnet 106 is surrounded by four magnets of opposite polarity and four magnets of the same polarity. Therefore, the distribution pattern of the magnetic field in the upper electrode 101 is uniform except for the portion near the edge. Furthermore, because of the presence of four magnets with opposite polarities for each magnet, the magnetic flux 107 does not penetrate deeply into the reaction vessel 100, but instead bends within a short distance, in the direction of the magnetic poles with different polarities. Go to Therefore, a strong magnetic field exists on the lower surface of the upper electrode 101, and the strength of the magnetic field toward the lower electrode 102 is rapidly attenuated. Such conditions create a magnetic field free environment in the region near the surface of the wafer 130.

The uniform distribution pattern of the magnetic field depends on the upper electrode 10.
It ends at the edge of 1. The outermost magnets have only two or three magnets with opposite polarities at very close distances. Top plate 10
In the plan view of FIG. 1, as shown in FIG. 9 showing the magnet arrangement, reference numerals 122, 123, 124,
The magnets on the line indicated by 125 exist with alternating polarities, each of which has three magnets of opposite polarity at close distance. Therefore, each of these magnets creates a magnetic flux that forms a closed loop. On the other hand, reference numeral 118,
The magnets above the lines indicated by 119, 120 and 121 have the same polarity towards the interior of the reaction vessel 100. Each of these magnets has only two magnets of opposite polarity at close distances. Therefore, the magnetic fluxes emitted from these magnets extend deeper inside the reaction container 100 than those of the other magnets 106. Note that reference numeral 116 indicates the Y axis, and 117 indicates the X axis.

When the plasma is generated, the upper electrode 10
Electrons and ions in the vicinity of 1 are forced to move under the E × B drift. Bulk plasma (bulk p
There is no DC (direct current) electric field in lasma (volumetric plasma). Therefore, the electrons in the bulk plasma simply follow the magnetic flux lines. Since there is no magnetic field on the surface of the wafer, the electrons just above the wafer are unaffected by the magnetic field.

However, the lines 118, 119, 12
The magnetic flux associated with the magnet located above 0, 121 extends toward the lower electrode 102. As the electrons move along the magnetic flux, the plasma density associated with these locations will increase. That is, the plasma density becomes non-uniform over the entire surface of the wafer. As a result, the processing rate on the wafer surface is likewise non-uniform. For example, in dry etching applications, line 11
The edge speed at the locations corresponding to 8,119,120,121 will increase. This is shown diagrammatically in FIG. In FIG. 10, 126, 12
The area indicated by 7,128,129 is wafer 1
It has a higher etching rate compared to the rest of 30. In practical applications, it was observed that the etch rate non-uniformity across a 300 mm diameter wafer is approximately plus or minus 15%.

At present, the majority of wafer processing must be done on the surface of the wafer with very good process speed uniformity. In general, an acceptable non-uniformity for a 200 mm diameter wafer or a 300 mm diameter wafer is less than plus or minus 5%.
Therefore, the plasma source described above cannot be used for most wafer processing.

It is an object of the present invention to produce a nearly uniform magnetic flux distribution pattern under the entire rf electrode surface, so that a uniform processing speed can be achieved over the entire wafer surface. Another object of the present invention is to provide a magnet array that creates a point cusp magnetic field for plasma generation and a plasma processing apparatus that can create a uniform plasma distribution.

[0017]

In order to achieve the above-mentioned object, a magnet array and a plasma processing apparatus for producing a point cusp magnetic field for plasma generation according to the present invention are configured as follows.

The magnet array of the present invention is used in a plasma processing apparatus having at least an electrode arranged above the surface of a wafer and an outer insulating member for supporting the electrode. The magnet array is composed of a plurality of magnets arranged separately on the outer surface of the electrode and a plurality of magnets arranged separately on a region corresponding to the outer surface of the insulating member. In the above structure, the magnets associated with the electrodes and the magnets associated with the insulating member are arranged so as to satisfy a positional and magnetic relationship for forming a predetermined magnet array.

In the above magnet arrangement, the magnets associated with the insulating member are arranged so that their positions are raised.

In the above magnet arrangement, the magnets associated with the insulating member are tilted so that the tips of their magnetic axes face the upper spot above the center of the electrode.

In the magnet arrangement described above, the electrode has a central region portion and an outer peripheral portion, and the magnet associated with the insulating member is arranged on the outer peripheral portion.

The plasma processing apparatus of the present invention comprises an upper electrode,
It is composed of an insulating member that supports the upper electrode on the outside thereof, a lower electrode on which a wafer is mounted, a reaction vessel including a capacitively coupled plasma source, and a magnet array that creates a point cusp magnetic field below the upper electrode. ing. The magnet array is composed of a plurality of magnets spaced apart on the outer surface of the upper electrode and a plurality of magnets spaced apart in a region corresponding to the outer surface of the insulating member. In this structure, the magnet associated with the upper electrode and the magnet associated with the insulating member are arranged so as to satisfy a predetermined positional and magnetic relationship that creates a predetermined magnet array.

In the plasma processing apparatus, the magnets associated with the insulating member are arranged so as to raise their positions.

In the plasma processing apparatus, the magnets related to the insulating member are tilted so that the tips of their magnetic axes face the upper spot above the center of the upper electrode.

In the plasma processing apparatus, the upper electrode has a central region portion and an outer peripheral portion, and the magnet associated with the insulating member is arranged in the outer peripheral portion.

[0026]

Preferred embodiments will be described below with reference to the accompanying drawings. The details of the invention will be clarified through this description of the embodiments.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a plasma processing apparatus having a magnet array according to the first embodiment. The magnet array includes a number of magnets 6 arranged on the upper electrode 1. Each of the magnets 6 has the same shape and the same magnetic force. FIG. 2 is a plan view showing a pattern of magnet arrangement on the upper electrode 1 viewed from the upper side or the lower side. In FIG. 2, a number of small circles indicate the end faces of each magnet 6. Further, the letters N and S indicate the magnetic polarity of the magnet 6 as viewed from below. The magnetic poles on the lower side of the magnet 6 are arranged so as to be alternately opposite. The X-axis 16 and the Y-axis 17 are shown in FIG.

The basic hardware structure of the plasma processing apparatus of this embodiment is the same as that of the plasma processing apparatus except for the magnetic arrangement.
It is almost the same as that described in the prior art.

The plasma processing apparatus has a reaction container 50. The reaction container 50 includes an upper electrode 1, a lower electrode 2, and insulating members (or insulators) 3 and 4 that electrically insulate the electrodes from the rest of the reaction container 50. The reaction container 50 includes an upper wall (ceiling wall) 14, a cylindrical side wall 5,
And the bottom wall 15 portion. Upper electrode 1
The insulating member 3 arranged so as to support the upper electrode is usually in the shape of a ring. A dielectric ring plate is preferably used as the insulating member 3. The insulating member 3 is fixed to the cylindrical side wall 5. The upper electrode 1 is made of a metal, usually a non-magnetic metal such as aluminum. The lower surface of the upper electrode 1 may or may not be surrounded by a thin plate made of a different material such as Si (silicon). This is to obtain the desired chemical reaction in the plasma and on the surface of the wafer. The thin plate is not shown in the figure and is therefore not shown. In addition, the upper electrode 1
Can also be cooled by flowing a cooling liquid through a passage formed in the upper electrode 1. This passage is likewise not shown in FIG.

The upper electrode 1 is given an rf current from the rf power source 13 via the matching circuit 8. The frequency of the rf current is not critical, preferably 10-300 MH
It is included in the range of z. The process gas is supplied into the reaction container 50 through the plurality of gas inlets 9. The reaction container 50 has a gas outlet 1 formed in the cylindrical side wall 5.
Exhausted via 0. As shown in FIG. 1, the process gas inlet 9 is provided around the side wall 5 of the reaction vessel 50. However, different mechanisms for supplying the process gas into the reaction vessel 50 can be used.
For example, the process gas can be supplied via a gas inlet formed in the upper electrode 1.

The plurality of magnets 6 are arranged on the outer surfaces of the upper electrode 1 and the insulating member (dielectric ring plate) 3. The insulating member 3 is, as shown in FIGS. 1 and 2,
It exists around the upper electrode 1. The magnets 6 are arranged in a form orthogonal to each other along a vertical line, so that the polarities of the magnets 6 directed toward the inside of the reaction container 50 are opposite to the magnets that are linearly adjacent to each other, and the magnets that are diagonally adjacent to each other. Will be the same between and. The distance between two adjacent magnets of opposite polarity is not critical and can be varied in the range 5-100 mm. The height of the magnet is likewise unimportant and is usually greater than 2 mm. The cross-sectional shape of the magnet 6 is square or circular. If the cross-sectional shape is circular, the diameter of the magnet 6 is 3-50m.
It is in the range of m. This value is not important and can be selected by considering the thickness of the upper electrode 1 and the dimensions of the reaction vessel. Usually, all magnets are made of the same magnetic material so that their magnetic poles have the same magnetic field strength. The strength of each magnetic field at the poles is not important. Depending on the type of application and the size of the wafer (or substrate), the value of magnetic field strength will vary.

Generally, the distance from the magnet 6 to the lower surface of the upper electrode 1 is determined by the thickness of the upper electrode 1. The thickness of the upper electrode 1 is not critical and is usually greater than 3 mm. However, the strength of the magnetic field on the lower surface of the upper electrode 1 is weakened as the thickness of the upper electrode is increased.
In order to avoid weakening the strength of the magnetic field on the lower surface of the upper electrode 1, it is possible to form a hole in the upper electrode 1 and dispose the magnet 6 in the hole as shown in FIG. The structure for setting the magnet on the upper electrode 1 reduces the distance from the magnet to the lower surface of the upper electrode 1. Similarly, the magnet 6 can be arranged in a hole formed in the insulating member 3 as shown in FIG.

When an rf current is applied to the upper electrode 1 under an appropriately low pressure, for example, a pressure of 1 to 20 Pa, plasma is generated by a capacitive coupling type mechanism. This plasma is then confined by the closed magnetic flux 7.

The lower electrode 2 is provided on the wafer holder 51. The wafer holder 51 is fixed to the bottom wall 15. The lower electrode 2 is the insulating member 4 of the wafer holder 51.
Is located on the upper surface of. The insulating member 4 electrically isolates the lower electrode 2 from the rest of the reaction vessel 50. The wafer 23 is mounted on the lower electrode 2. Similarly, from the power source 12 to the matching circuit 11
Rf current is given via the. If an rf current is applied to the lower electrode 2, the frequency of the current is usually in the range below 20 MHz.

An important feature of the magnet array in the first embodiment of the present invention is that the same magnet array extends outside the upper electrode 1 so that it extends over the ring-shaped insulating member 3 around the upper electrode 1. It means that the area has been extended. This magnet arrangement produces a magnetic field with a closed magnetic flux 7 near the inner surfaces of the upper electrode 1 and the insulating member 3.

Due to the magnet arrangement described above, the outermost magnet 6 exists at the location of the insulating member 3. The magnet 6, which lies above the line indicated by the reference numbers 18, 19, 20, 21 in particular, lies within the insulation member 3,
It is separated from the upper electrode 1. These magnets are basically for expanding the magnetic field, thereby making it possible to create a non-uniform plasma. Since these magnets 6 are located away from the upper electrode 1,
The expanding magnetic flux towards the lower electrode 2 is likewise also under the insulating member 3 and at a distance from the surface area of the upper electrode 1. This results in a uniform pattern of magnetic flux distribution under the upper electrode 1. Since the expanded magnetic flux emitted from the outermost magnet 6 on the ring-shaped insulating member 3 is further away from the wafer 23, and no plasma is generated below the insulating member 3, the wafer 23 The effect of the extended magnetic flux on the above processing speed is neglected. This results in a radially uniform plasma and uniform processing rate across the wafer surface.

According to the first embodiment, the point cusp magnetic field generated by the above-mentioned magnet array on the upper electrode 1 and the ring-shaped insulating member 3 is applied to the capacitively coupled plasma processing apparatus. The point cusp magnetic field locates a magnetic flux that extends away from the periphery of the upper electrode 1 towards the interior space of the reaction vessel, thereby minimizing the formation of a non-uniform plasma across the surface of the wafer 23. , Or lose.

Next, a second embodiment of the present invention will be described with reference to FIG. The plasma processing apparatus of the second embodiment is a modification of the first embodiment. Here, only the magnet arrangement is modified, and the other hardware configuration is the same as that described in the first embodiment. Therefore, only the magnet arrangement is described here. Figure 4
In, each of the elements that are substantially identical to those shown in FIG. 1 is labeled with the same reference numeral.

The pattern of the magnetic arrangement is the same as that described in the first embodiment. That is, the magnets 6 are arranged in an orthogonal form along the vertical line,
Therefore, the polarities of the magnetic poles 6 directed to the inside of the reaction container 50 are opposite to those of the magnets that are linearly adjacent to each other, and are the same as those of the magnets that are diagonally adjacent to each other. The magnets 6 arranged on the upper electrode 1 are present on the same plane in the same arrangement manner. As shown in FIG. 4, the magnet 6 arranged on the ring-shaped insulating member 3 is gradually raised when the position of the magnet 6 is further apart from the upper electrode 1. The pattern of the magnet array viewed from the upper side or the lower side does not change as compared with that of the first embodiment.

The size and strength of the magnetic field of the magnet 6 are
It is the same as those described in the first embodiment.

The magnet arrangement described above also
As described in the first embodiment, a uniform magnetic field distribution is created below the upper electrode 1. Further, the ring-shaped insulating member 3
The strength of the magnetic field at the lower surface of is gradually reduced in the direction towards the side wall 5. This is because the magnet 6 in the insulating member 3 gradually increases in height in the direction toward the side wall 5. This is shown diagrammatically in FIG. Thus, the extended magnetic flux in the outermost magnetic field is in the ring-shaped insulating member 3 or extends only slightly below the lower surface of the insulating member 3. Therefore, the movement of the plasma along the lines forming the magnetic field is further suppressed. This improves plasma uniformity across the surface of the wafer 23.

Next, a third embodiment of the present invention will be described with reference to FIG. The plasma processing apparatus of the third embodiment is
Similarly, this is also a modification of the first embodiment. First here
Only the magnet arrangement is modified as compared to the embodiment, and the other basic hardware configuration is the same as that described in the first embodiment. Therefore, only the magnet arrangement is described below with reference to FIG.
Elements in FIG. 5 that are substantially identical to those shown in FIG. 1 are labeled with the same reference numerals.

The pattern of the magnet array is the same as that described in the first and second embodiments. The magnet 6 arranged on the upper electrode 1 is
Exist on the same plane corresponding to the upper surface of the magnets 6 and, further, the magnetic axes 24 of each magnet 6 are parallel to each other. On the other hand, the magnets 6 arranged on or in the ring-shaped insulating member 3 are on another plane different from the plane mentioned above, their magnetic axes 24 not being parallel to those on the upper electrode 1. . The magnets 6 arranged on the ring-shaped insulating member 3 are inclined, so that the upper ends of the respective magnetic axes face the upper spot above the central portion of the upper electrode 1. The inclination angle of the outermost magnet is
It is smaller than that of the inner magnet. Insulation member 3
The arrangement of the magnets 6 at further minimizes the penetration of magnetic flux extending into the reaction vessel 50 at the periphery of the magnet arrangement. This improves plasma uniformity on the wafer surface. It should be noted that in the third embodiment, the thickness of the ring-shaped insulating member arranged in the region around the upper electrode 1 is relatively increased.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The plasma processing apparatus of the fourth embodiment is the second
It is a modification of the embodiment. Here, only the shapes of the upper electrode and the insulating member are modified as compared with the second embodiment,
The other hardware configuration is the same as that described in the second embodiment. The magnet arrangement is different from that of the first embodiment, but is the same as that of the second embodiment. Therefore, here only the upper electrode and the insulating member will be described in relation to the features of the magnet arrangement with reference to FIG. In FIG. 6, elements that are substantially the same as those shown in FIG. 4 are each assigned the same reference number.

The upper electrode 61 has two parts. The first portion is a central area portion 61 having a circular flat plate shape.
a and the other portion is the outer peripheral portion 61b. The central region portion 61a is the upper plate 1 described in the first embodiment.
Corresponding to. The outer peripheral portion 61b is the upper electrode 6 in FIG.
It is formed by bending the peripheral portion of 1 upward. The ring-shaped insulating member 62 having a relatively large thickness has an inner surface 62a formed to have an inclination. The inner edge is lower and the outer edge is higher on the inner surface 62a of the insulating member 62. The inner surface 62a has a straight slope in the shape of its cross section. The upper electrode 61 is attached to and supported by the inner surface of the insulating member 62, so that the outer peripheral portion 61b is held in contact with the inclined inner surface 62a. The pattern of the magnet arrangement of the magnets 6 is the same as that described in the second embodiment. That is, the magnets 6 arranged in the central region portion 61a exist on a plane of the same height, which corresponds to the upper surface of the central region portion 61a. The position of the magnet 6 arranged on the outer peripheral portion 61b gradually increases as the position is changed outward. All of the magnets 6 are arranged on the upper electrode 61.

The arrangement of the magnets 6 arranged on the outer peripheral portion 61b corresponding to the ring-shaped insulating member 62 removes the magnetic flux extending at the edge portion of the magnet arrangement.

Next, a fifth embodiment of the present invention will be described with reference to FIG. The plasma processing apparatus of the fifth embodiment is a modification of the fourth embodiment. In the fifth embodiment, the upper electrode 6
1 and the characteristic shape of the insulating member 62 are shown. In the fifth embodiment, the magnet arrangement is modified as compared to the fourth embodiment, and the other hardware configuration is the same as that described in the fourth embodiment. The magnet arrangement is substantially the same as that in the third embodiment.
In FIG. 7, elements that are substantially the same as those shown in FIGS. 1 and 6 are each assigned the same reference numeral.

The upper electrode 61 has a central region portion 61a and an outer peripheral portion 61b. The ring-shaped insulating member 62 has an inner surface 62a formed to have an inclination.
The inner surface 62a has a linear inclination in its cross-sectional shape. The magnets 6 arranged on the central region 61a lie on a plane of the same height and their magnetic axes are parallel to each other. The magnets 6 located on the outer peripheral portion 61b gradually increase in height as their position changes outward, and furthermore they have their magnetic axes in the outer peripheral portion 61b.
It is arranged so as to be perpendicular to the upper surface of b. All of the magnets 6 are arranged on the upper electrode 61.

The array of magnets 6 located on the outer peripheral portion 61b corresponding to the ring-shaped insulating member 62 further minimizes and eliminates the magnetic flux extending at the peripheral portion of the magnet array.

[0050]

According to the present invention, the magnet array for generating the point cusp magnetic field or the plasma processing apparatus including the magnet array minimizes or eliminates the magnetic flux existing in the predetermined peripheral region of the upper electrode. Therefore, the uniformity of the plasma distribution over the surface of the wafer can be improved, thereby improving the processing uniformity on the surface of the wafer.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a plasma processing apparatus according to a first embodiment.

FIG. 2 is a plan view showing a magnet array on the upper electrode and the insulating member in the first embodiment.

FIG. 3 is a sectional view of a plasma processing apparatus as a modified example of the first embodiment.

FIG. 4 is a sectional view of a plasma processing apparatus according to a second embodiment.

FIG. 5 is a sectional view of a plasma processing apparatus according to a third embodiment.

FIG. 6 is a sectional view of a plasma processing apparatus according to a fourth embodiment.

FIG. 7 is a sectional view of a plasma processing apparatus according to a fifth embodiment.

FIG. 8 is a sectional view of a conventional plasma processing apparatus.

FIG. 9 is a plan view showing a magnet array on an upper electrode in a conventional device.

FIG. 10 is a plan view showing a wafer to show areas of technical problem.

[Explanation of reference symbols]

1 Upper electrode 2 Lower electrode 3 Insulation member 4 Insulation member 6 magnets 7 magnetic flux 23 wafers 51 Wafer holder 61 Upper electrode 62 Insulation member

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Claims (8)

[Claims] 1. A plurality of magnets, which are used in a plasma processing apparatus having an electrode arranged above a surface of a wafer and an outer insulating member supporting the electrode, and are arranged apart from each other on an outer surface of the electrode, and A plurality of magnets are arranged apart from each other in a region corresponding to the outer surface of the insulating member, and in the above, the magnets related to the electrodes and the magnets related to the insulating member are arranged in a positional and magnetic manner to form a predetermined magnet array. A magnet array for generating a point cusp magnetic field for plasma generation, which is arranged so as to satisfy the above relationship. 2. The magnet array for generating a point cusp magnetic field for plasma generation according to claim 1, wherein the magnets related to the insulating member are arranged so as to raise their positions. 3. The plasma according to claim 1, wherein the magnets related to the insulating member are inclined so that the tips of their magnetic axes are directed to the upper spot above the center of the electrodes. A magnet array that creates a point cusp magnetic field for generation. 4. The plasma generation according to claim 2, wherein the electrode has a central region portion and an outer peripheral portion, and the magnet related to the insulating member is disposed on the outer peripheral portion. A magnet array that creates a point cusp magnetic field. 5. An upper electrode, an insulating member supporting the upper electrode on the outer side thereof, a lower electrode on which a wafer is mounted, a reaction vessel including a capacitively coupled plasma source, and an upper electrode separated from the outer surface. A plurality of magnets, and a plurality of magnets arranged apart from each other on a region corresponding to the outer surface of the insulating member, wherein the magnets are associated with the upper electrode and the magnets are associated with the insulating member. Is arranged so as to satisfy predetermined positional and magnetic relationships, and a magnet array for creating a point cusp magnetic field is provided below the upper electrode, and the plasma processing apparatus. 6. The plasma processing apparatus according to claim 5, wherein the magnets associated with the insulating member are arranged so as to enhance their positions. 7. The magnet according to claim 5, wherein the magnets associated with the insulating members are tilted so as to direct the tips of their magnetic axes toward an upper spot above the center of the upper electrode. Plasma processing equipment. 8. The plasma processing apparatus according to claim 6, wherein the upper electrode has a central region portion and an outer peripheral portion, and the magnet associated with the insulating member is disposed in the outer peripheral portion. .