WO2003049171A1

WO2003049171A1 - Exhaust ring mechanism, and plasma treatment device using the exhaust ring mechanism

Info

Publication number: WO2003049171A1
Application number: PCT/JP2002/012826
Authority: WO
Inventors: Toshiki Takahashi
Original assignee: Tokyo Electron Limited
Priority date: 2001-12-07
Filing date: 2002-12-06
Publication date: 2003-06-12
Also published as: AU2002354107A1; JP2003174020A; JP4392852B2

Abstract

An exhaust ring mechanism includes a lower electrode which is disposed in a treatment chamber to hold a wafer (W) and an exhaust ring mechanism disposed between the lower electrode and inner walls of the treatment chamber. The exhaust ring mechanism has an exhaust ring and a magnetic field forming unit to form a magnetic field parallel to a main surface of the exhaust ring. The exhaust ring mechanism prevents plasma leakage from a plasma area to a non-plasma area by the formed magnetic field. A plasma treatment device employs the exhaust ring mechanism.

Description

Specification

Exhaust ring mechanism and plasma processing apparatus using the exhaust ring mechanism

Technical field

The present invention relates to a plasma processing apparatus, and more particularly, to an exhaust ring mechanism and a plasma processing apparatus used in a plasma processing apparatus capable of confining plasma in a plasma region. Related.

Background art

2. Description of the Related Art A plasma processing apparatus is an apparatus that performs processing such as an etching process and a film forming process on an object to be processed such as a wafer by using plasma generated in a processing chamber. There are various types of plasma processing devices, for example, a capacitive coupling type and an inductive coupling type.

As the plasma processing apparatus of this capacitive coupling type, those having parallel-plate electrodes are widely used. The parallel plate type plasma processing apparatus has a processing chamber capable of maintaining a vacuum by an exhaust system including a vacuum pump. A holder serving also as a lower electrode for mounting an object to be processed such as a wafer is mounted in the processing chamber. Above the holder, an upper electrode is provided with a space (processing space). A high-frequency power supply for applying high-frequency power is provided to one of the upper and lower electrodes or both the upper and lower electrodes. Further, a focusing ring is provided on the outer peripheral edge of the holder.

In this configuration, the high-frequency power supply High-frequency power is applied to either the upper or lower electrode or both electrodes under vacuum, and plasma is generated in an atmosphere of the process gas introduced into the processing chamber. Perform plasma processing such as switching.

In addition, a ring-shaped exhaust ring having a plurality of exhaust holes is provided between the holding body and the inner peripheral wall of the processing chamber, and by-products and unnecessary products are passed through the exhaust holes of the exhaust ring. Process gas (used) is exhausted evenly around the plasma area.

The processing chamber is divided into a plasma region and a non-plasma region via the exhaust ring. In the plasma region side, the inner wall of the processing chamber is worn out due to snow and water ring by plasma mist, and is contaminated by by-products adhering and accumulating. Ceramic spraying is applied to the walls. On the other hand, in the non-plasma region, there is almost no attack by plasma ions, and there is little contamination by by-products. Therefore, no such measures are taken on the inner wall of the treatment chamber.

However, since the exhaust ring is provided with exhaust holes for exhaust throughout the entire surface, when the density of the plasma is increased, the exhaust holes are used to form a non-plasma region. Zuma leakage occurs. Due to this plasma leakage, the plasma density at the outer peripheral portion of the object to be processed is reduced, and as a result, there is a problem that the uniformity of plasma processing such as an etching rate is deteriorated. In addition, the plasma leakage may damage or contaminate the inner wall of the processing chamber in the non-plasma region.

As a countermeasure, plasma leakage is reduced by reducing the total area of the exhaust holes. Although there is a method to prevent this, this method has disadvantages such as limiting the amount of gas exhausted from the plasma region and causing stagnation of by-products. In particular, evacuation from a pressure close to the atmospheric pressure after opening to the atmosphere or after purging with nitrogen gas increases the evacuation time to reach a predetermined degree of vacuum, and as a result, lowers throughput. There is a problem that may be caused.

Disclosure of the invention

It is an object of the present invention to provide an exhaust ring mechanism capable of confining plasma in a plasma region in a processing chamber while ensuring sufficient gas exhaustability, and a plug mounted with the exhaust ring. It is to provide a zuma treatment device.

In the present invention, an exhaust ring mechanism that contacts a plasma region for performing plasma processing on an object to be processed in a processing chamber and forms an exhaust flow path for generated gas in the plasma region. The exhaust ring mechanism includes an exhaust ring having a surface in contact with the plasma region, and a magnetic field forming unit that forms a magnetic field having magnetic lines of force parallel to the surface direction of the exhaust ring. It is composed and blocks the passage of plasma ions and electrons by the formed magnetic field, confining the plasma in the plasma region and preventing the plasma leakage from the plasma region to the non-plasma region It becomes possible to do. As a result, the diffusion of the plasma is prevented, and the uniformity of the plasma density between the peripheral portion of the wafer W and the central portion of the wafer W is improved. In addition, plasma processing such as etching at the outer peripheral portion of the wafer W is prevented from lowering, and the in-plane uniformity of the plasma processing is maintained. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a configuration of a plasma processing apparatus and an exhaust ring mechanism according to a first embodiment of the present invention.

FIG. 2A is a plan view partially illustrating the operation of the exhaust ring mechanism shown in FIG. 1, FIG. 2B is a radial cross-sectional view of FIG. 2A, and FIG. It is sectional drawing of a direction.

FIG. 3A is a diagram showing a partial plane of an exhaust ring mechanism according to a second embodiment of the present invention, FIG. 3B is a diagram showing a radial cross-sectional configuration of FIG. 3A, and FIG. FIG. 3B is a diagram showing a cross-sectional configuration in the circumferential direction of FIG. 3A.

FIG. 4A is a view showing a partial plane of an exhaust ring mechanism according to a third embodiment of the present invention, and FIG. 4B is a view showing a radial cross-sectional configuration of FIG. 4A.

FIG. 5A is a diagram showing a partial plan view of a configuration of an exhaust ring mechanism according to a fourth embodiment of the present invention, and FIG. 5B is a diagram showing a direction of a magnetic field vector in the configuration of FIG. 5A. It is.

FIG. 6A is a view showing a partial plane of a plane configuration of an exhaust ring mechanism according to a fifth embodiment of the present invention, and FIG. 6B is a direction of a magnetic field vector in the configuration of FIG. 6A. FIG.

FIG. 7A is a diagram showing a partial plan view of a planar configuration of an exhaust ring mechanism according to a sixth embodiment of the present invention, FIG. 7B is a diagram showing a first magnet arrangement example, and FIG. FIG. 4 is a diagram showing an example of an arrangement of a second magnet.

FIG. 8A is a diagram showing a plan configuration of the exhaust ring in the exhaust ring mechanism according to the seventh embodiment of the present invention as viewed from above, and FIG. FIG. 8A is a diagram showing an example of the arrangement of magnets and the direction of a magnetic field vector in the configuration of FIG. 8A, and FIG.

FIG. 9A is a diagram showing a plan view of an exhaust ring in an exhaust ring mechanism according to an eighth embodiment of the present invention, as viewed from above, and FIG. 9B is an example of a magnet arrangement in the configuration of FIG. 9A. FIG. 4 is a diagram showing the direction of a magnetic field vector.

FIG. 1 OA is a diagram showing a plan view of the exhaust ring in the exhaust ring mechanism according to the ninth embodiment of the present invention as viewed from above, and FIG. 10B is a magnet in the configuration of FIG. 1 OA. FIG. 2 is a diagram showing an example of the arrangement of the magnetic field and the direction of a magnetic field vector.

Fig. 11A is a diagram showing an external configuration of a depot shield mechanism to which the function of the exhaust ring mechanism in each of the above-described embodiments is applied. Fig. 11B is a top view of the depot shield shown in Fig. 11A. Fig. 11C shows a plan view, Fig. 11C shows a side view of the deposit shield of Fig. 11A, and Fig. 11 D shows a part of the deposit shield where magnets are arranged in the radial direction. FIG. 12A shows the cross-sectional configuration of the depot shield mechanism to which the function of the exhaust ring mechanism in each of the above-described embodiments is applied. FIG. 12B shows the external configuration of FIG. Fig. 12C shows the top view of the depot shield shown in Fig. 12C, Fig. 12C shows the external view of the depot shield of Fig. 12A viewed from the side, and Fig. 12D shows the magnet in the depot shield. The invention showing the partial cross-sectional configuration of the configuration in which is arranged in the circumferential direction is carried out. Best form for

Hereinafter, embodiments according to the present invention will be described in detail. FIG. 1 is a diagram schematically showing a configuration of a plasma processing apparatus and an exhaust ring mechanism according to a first embodiment of the present invention. 2A shows a partial plan view of the configuration of the exhaust ring mechanism 7, FIG. 2B shows a cross-sectional configuration along the radial direction, and FIG. 2C shows a cross-sectional configuration along the circumferential direction. are doing.

As shown in FIG. 1, the plasma processing apparatus is roughly divided into a processing chamber 1, a holder 2, an upper electrode 3, a matching unit 4, a high-frequency power supply 5, a focus ring 6, and an exhaust ring. The mechanism 7 consists of an exhaust system 12 and a gas supply system (purge gas and process gas) 13.

The processing chamber 1 is formed of a conductive material such as aluminum and has an airtight structure for maintaining a predetermined high vacuum state. In addition, the inner walls exposed to plasma are subjected to well-known corrosion-resistant treatment such as alumite treatment.

The holder 2 is mounted in the processing chamber 1, on which an object to be processed (for example, a wafer) W is placed and held by an electrostatic chuck (not shown). Further, a delivery mechanism (not shown) is provided, and a wafer is transferred to and from a wafer transfer mechanism (not shown). Further, a high-frequency power source 5 is connected to the holder 2 via a matching device 4 described later, and also serves as a lower electrode to which high-frequency power is applied for plasma generation. Hereinafter, the holder 2 is referred to as a lower electrode 2.

A focusing ring 6 is arranged on the outer peripheral edge of the mounting surface on which the wafer is mounted on the lower electrode 2. The focusing ring 6 is formed in a ring shape by using a silicon or the like, and the inside thereof has a gap. Ha is inserted. The focus ring 6 allows the plasma generated between the lower electrode 2 and the upper electrode 3 to be focused on the wafer W.

The upper electrode 3 is provided above the lower electrode 2 in the processing chamber 1 so as to be opposed to and parallel to the mounting surface of the lower electrode at a predetermined interval from the lower electrode 2. The upper electrode 3 is formed in a hollow shape like a box, and has a function of diffusing a process gas, for example, an etching gas into the processing chamber in a shower shape to supply the gas.

The high-frequency power supply 5 applies a high-frequency power of, for example, 13.5.6 MHz to the lower electrode 2. The matching unit 4 is provided between the high-frequency power source 5 and the lower electrode 2 to match the impedance between the upper electrode and the lower electrode during discharge and to reduce the applied high-frequency power. Acts to minimize the loss due to reflected waves and the like. By applying high-frequency power with this consistency to the process gas atmosphere of the process gas supplied into the processing chamber 1, the lower electrode 2 and the upper electrode 3 Plasma occurs in between.

The exhaust ring mechanism 7 is formed in a ring shape on the outer periphery of the mounting surface of the lower electrode 2 (the outer periphery of the focusing ring 6) and arranged. The inside of the processing chamber 1 is divided into a plasma region and a non-plasma region by the upper and lower surfaces of the main surface of the exhaust ring mechanism 7. In this case, the plasma region above the upper surface of the exhaust ring mechanism 7 is a plasma region, and the plasma region below the lower surface is a non-plasma region. For example, as shown in FIGS. 2A and 2B, the exhaust ring mechanism 7 includes an exhaust ring 71 and a main surface direction (a direction parallel to the exhaust ring main surface) of the exhaust ring 71. ), And a magnetic field forming unit 72 for forming the magnetic field of. However, the mounting surface of the lower electrode 2 is parallel to the main surface of the exhaust ring. The exhaust ring mechanism 7 is in contact with a plasma region in which the plasma processing is performed on the wafer W in the processing chamber 1 and forms an exhaust flow path for generated gas in the plasma region.

In the exhaust ring 71, a plurality of circular exhaust holes 71A are uniformly distributed over the entire circumference as shown in the figure, and the exhaust rings 71A are formed through these exhaust holes 71A. Then, the gas in the plasma region is exhausted outside the processing chamber 1 via the non-plasma region. In this example, the exhaust holes are illustrated as being formed in triple circles in the circumferential direction, but the present invention is not limited to this, and the exhaust holes may be evenly distributed on the main surface of the exhaust ring. However, any arrangement is acceptable as long as the exhaust capacity and characteristics are taken into consideration.

As shown in FIG. 2A, the magnetic field forming unit 72 of the present embodiment includes a first ring magnet 72 A (a permanent magnet or an electromagnet) that covers the inner peripheral surface of the exhaust ring 71. It is composed of a second ring magnet 72 B (permanent magnet or electromagnet) that covers the outer peripheral surface of the exhaust ring 71. With this configuration, as shown in FIG. 2B, the magnetic field forming section 72 moves in the exhaust ring 71 in a direction parallel to the main surface from the lower electrode 2 to the inner wall of the processing chamber 1. Create a magnetic field. This magnetic field traps the generated plasma in the above-mentioned plasma region and prevents the leakage of the plasma to the non-plasma region. Works.

Specifically, between the first ring magnet 72A and the second ring magnet 72B, as shown by an arrow X in FIG. A magnetic field in the direction parallel to the main surface is formed on the magnet 72B. Since the magnetic field lines B of this magnetic field are substantially perpendicular to the direction in which the plasma and the electrons leak, the plasma and the electrons in the plasma region are exhausted as shown in FIG. 2B. Even when passing through 1A, the plasmion and electrons rotate around the magnetic field line B under the action of the magnetic field as shown in Fig. 3C. However, FIGS. 2B and 2C show only the minus ion. The same applies to the following embodiments to be described later.

The plasma ions and electrons collide with the inner peripheral surface of the exhaust hole 71A, do not leak to the non-plasma region, and are confined in the plasma region. Therefore, it is possible to prevent the diffusion of the plasma at the outer peripheral portion of the wafer W, and to maintain the uniformity of the plasma density between the peripheral portion of the wafer W and the central portion of the wafer W. Therefore, it is possible to prevent a reduction in the processing speed (etching rate) such as etching at the outer peripheral edge portion of the wafer W, and to improve the in-plane uniformity of the plasma processing.

Further, the exhaust ring mechanism 7 includes a magnetic field sealing portion 73 as shown in FIGS. 2A and 2B, for example. The magnetic field sealing portion 73 is made of a magnetic material such as iron, for example, and is made of a magnetic ring 71 and first and second ring magnets 72 A and 72 B as shown in the figure. It is formed as a magnetic housing that is housed integrally. Below The magnetic field sealing portion 73 will be described as a magnetic container 73.

As shown in FIG. 2B, a magnetic path Y is formed from the outer peripheral surface to the inner peripheral surface of the magnetic storage body 73 integrally stored as described above, and the exhaust ring is formed. 7 It is possible to prevent the magnetic field from leaking, and it is possible to effectively use the magnetic field. As a result, it is possible to more reliably confine the plasma within the plasma region. Therefore, the plasma miions and electrons in the processing chamber 1 are reliably closed in the plasma region, and the uniformity of the plasma processing can be further improved. In addition, it is possible to prevent the inner wall of the processing chamber 1 in the non-plasma region from being damaged by the plasma and from being contaminated with by-products.

Further, since the first ring magnet 72A is adjacent to the lower electrode 2, a magnetic field also acts on the outer peripheral edge of the upper surface of the lower electrode 2, and this magnetic field is generated when the outer peripheral edge of the wafer W is etched. The in-plane uniformity of plasma processing such as etching rate can be further improved.

According to the first embodiment described above, the exhaust ring mechanism 7 forms the radial magnetic field of the processing chamber, and the plasma ions and the electrons try to pass through the exhaust holes of the exhaust ring. However, the generated magnetic field acts on the plasma and the electrons to swirl and collide in the exhaust hole, preventing the plasma and the electrons from passing and confining the plasma to the plasma region. be able to. Therefore, the diffusion of the plasma at the outer peripheral portion of the wafer W is prevented, and the uniformity of the plasma density between the peripheral portion of the wafer W and the central portion of the wafer W can be improved. In addition, the wafer W The plasma processing such as etching can be prevented from lowering, and the in-plane uniformity of the plasma processing can be maintained.

In addition, the inner wall of the processing chamber 1 in the non-plasma region can be prevented from being damaged by plasma, and can be prevented from being contaminated with by-products. Then, a magnetic field is formed by the magnetic field forming portion also on the outer peripheral edge of the upper surface of the lower electrode 2, and the uniformity of plasma processing such as etching can be improved by the influence of the magnetic field. Furthermore, since the exhaust ring and the first and second ring magnets are housed integrally in the magnetic housing, the magnetic housing prevents the leakage of the magnetic field, and effectively uses the magnetic field without waste. The plasma can be more reliably confined to the plasma region.

Next, an exhaust ring mechanism used in the plasma processing apparatus according to the second embodiment of the present invention will be described. FIG. 3A is a diagram illustrating a partial plan view of a configuration of an exhaust ring mechanism according to a second embodiment of the present invention, and FIG. 3B is a cross-sectional view of the processing chamber in FIG. 3A in a radial direction. FIG. 3C is a diagram showing a configuration, and FIG. 3C is a diagram showing a cross-sectional configuration thereof in a circumferential direction of FIG. 3A.

The exhaust ring mechanism 10 used in the plasma processing apparatus includes, for example, an exhaust ring 101 and a magnetic field forming unit 102 as shown in FIGS. 3A and 33B. The magnetic field generator 102 is composed of a plurality of magnets 102 A radially arranged at predetermined intervals in the circumferential direction of the exhaust ring 101. Each of the magnets 102A is formed in a plate shape, and is attached so as to fill an elongated hole formed in the exhaust ring 101. Then, the adjacent magnets 10 2 A in the exhaust ring 101 Between them, a magnetic field is formed in the direction parallel to the exhaust ring main surface in the clockwise direction (CW) as shown by arrow Z in Fig. 3A.

The magnetic field lines B of this magnetic field are substantially perpendicular to the direction in which plasma and electrons leak. For this reason, even if plasma ions and electrons in the plasma region try to pass through the exhaust hole 101A of the exhaust ring 101 as shown in FIG. Thus, it turns around the line of magnetic force under the action of the magnetic field. Therefore, the plasmion and the electrons collide with the inner peripheral surface of the exhaust hole 101A of the exhaust ring 101, do not leak to the non-plasma region, and are confined in the plasma region. .

As described above, according to the exhaust ring mechanism of the second embodiment, a magnetic field in the CW direction is formed between a plurality of magnets arranged radially, and plasma and electrons pass through the exhaust holes. Even so, it turns due to the action of the magnetic field, collides with the exhaust holes, and is prevented from passing. For this reason, the plasma can be confined in the plasma region, and the same operation and effect as those of the first embodiment can be obtained.

Next, an exhaust ring mechanism used in a plasma processing apparatus according to a third embodiment of the present invention will be described. FIG. 4A is a diagram showing a partial plan view of a configuration of an exhaust ring mechanism according to a third embodiment of the present invention, and FIG. 4B is a diagram showing a radial cross-sectional configuration of FIG. 4A. .

The magnetic field forming unit 112 in the exhaust ring mechanism is composed of first and second ring magnets 112A and 112B, similarly to the exhaust ring mechanism 7 shown in FIG. 2 described above. However, the exhaust of this embodiment As shown in FIGS. 4A and 4B, the ring mechanism 11 includes first and second ring magnets 11 A and 11 B which are formed on the inner peripheral lower surface of the exhaust ring 11 1 and the outer side. They are arranged in contact with the lower surface of the peripheral portion.

In this configuration, the magnetic force passes through the exhaust ring 111 and moves from the first ring magnet 112A to the second ring magnet 112B. Formed. This magnetic field is generally formed as a horizontal magnetic field that crosses the exhaust hole 111A of the exhaust ring 111 substantially horizontally as shown in FIG. 4B.

Since the magnetic field lines B of this magnetic field are substantially orthogonal to the direction in which the plasma and the electrons leak as in the above-described embodiments, the plasma and the electrons in the plasma region are exhausted as shown in FIG. 4B. Even if it tries to pass through the exhaust hole 71 A of the ring 71, the plasma myon and the electrons rotate around the magnetic field line B under the action of the magnetic field and leak to the non-plasma region. Without being trapped in the plasma region. Therefore, in this embodiment, the same operation and effect as those of the exhaust ring mechanism 7 shown in FIG. 2A can be obtained. In the first to third embodiments described above, there is no limitation. Instead, each component can be redesigned as needed. For example, the magnetic field forming unit is not limited to the first and second ring magnets or the plate-like magnets, but may use an electromagnet having the same form as these magnets. Instead of the first and second ring magnets, arc-shaped magnets may be arranged along the entire circumference of the exhaust ring. Also, the magnetic field forming unit may form a magnetic field parallel to the main surface direction in the exhaust ring. Preferably, the direction of the magnetic field can be in any direction. Next, an exhaust ring mechanism used in a plasma processing apparatus according to a fourth embodiment of the present invention will be described. FIG. 5A is a diagram illustrating a partial plan view of a configuration of an exhaust ring mechanism according to a fourth embodiment of the present invention, and FIG. 5B is a diagram illustrating a direction of a magnetic field vector in the configuration of FIG. 5A. FIG.

The exhaust hole 71A opened by the exhaust ring 71 of the exhaust ring mechanism in the first embodiment shown in FIG. 2 described above has a circular shape, but in the fourth embodiment, In this configuration, the slit-shaped exhaust holes are radially arranged from the inner side to the outer side.

The exhaust ring mechanism 13 includes an exhaust ring 13 1 and a magnetic field forming unit 13 2. As shown in FIG. 5A, the magnetic field forming section 13 2 includes a first ring magnet 13 2 A covering the inner peripheral surface of the exhaust ring 13 1, and an outer peripheral surface of the exhaust ring 13 1. It is composed of a second ring magnet 132B and a coil covering the second magnet.

According to this configuration, as shown in FIG. 5B, the magnetic field forming unit 13 2 moves from the lower electrode 2 shown in FIG. 1 to the inner wall of the processing chamber 1 in the exhaust ring 13 1. Force ゝ A magnetic field is formed in the direction X 1 parallel to the main surface. This magnetic field acts to confine the generated plasma in the above-mentioned plasma region and prevent the leakage of the plasma to the non-plasma region.

In the present embodiment, it is possible to obtain the same operation and effect as those of the above-described first embodiment.

Next, the present invention is applied to a plasma processing apparatus according to a fifth embodiment of the present invention. The exhaust ring mechanism used will be described. FIG. 6A is a view showing a partial plane of a plane configuration of an exhaust ring mechanism according to a fifth embodiment of the present invention, and FIG. 6B is a view showing the direction of a magnetic field vector in the configuration of FIG. 6A. FIG.

The exhaust ring mechanism 14 used in this plasma processing apparatus includes, for example, as shown in FIGS. 6A and 6B, an exhaust ring 14 1 and a magnetic field forming section 142. The magnetic field forming part 142 is composed of a plurality of magnets 142 A radially arranged at predetermined intervals in the circumferential direction of the exhaust ring 141. Each magnet 142A is formed in a plate shape, and is attached along the slit-shaped exhaust hole 144A formed in the exhaust ring 141. I have. Then, between the adjacent magnets 14 2 A and 14 2 A at the exhaust ring 14 1, the clockwise rotation (CW) as shown by the arrow Z 1 in FIG. A magnetic field is formed.

According to the present embodiment, in addition to the operation and effect similar to the above-described first embodiment, the same operation and effect as the second embodiment can be obtained.

Next, an exhaust ring mechanism used in a plasma processing apparatus according to a sixth embodiment of the present invention will be described. FIG. 7A is a diagram showing a partial plane of a plane configuration of an exhaust ring mechanism according to a sixth embodiment of the present invention, and FIG. 7B is a diagram showing a first magnet arrangement example. FIG. 7C is a diagram showing an example of the arrangement of the second magnet.

The exhaust ring mechanism of the present embodiment includes the exhaust ring 151, a plurality of magnets 152A of the magnetic field forming unit, or the exhaust ring 151, and the magnets 152B. Let's do it. Exhaust ring 1 5 1 Similar to the exhaust ring in the fourth embodiment described above, slit-shaped exhaust holes 151A are arranged radially from the inside toward the outer periphery.

As shown in Fig. 7B, as a first arrangement example, magnets 152A for forming a magnetic field are spaced at an angle of 30 ° in the circumferential direction of exhaust ring 151. It is arranged radially. These magnets 152A are each formed in a plate shape, and are arranged and mounted on the lower surface side of the exhaust ring 1515.

As shown in FIG. 7C, as a second arrangement, magnets 15 2 B for forming a magnetic field are spaced at an angle of 45 ° in the circumferential direction of exhaust ring 15 1. It is arranged radially. These magnets 15A and 15B are each formed in a plate shape, and are arranged and mounted on the lower surface side of the exhaust ring 15I. In the first and second arrangement examples, between the adjacent magnets 15A and 15B, the clockwise direction (CW) as shown by the arrow Z1 in FIG. A magnetic field is formed.

In the present embodiment, it is possible to obtain the same operation and effect as in the above-described second embodiment.

Next, an exhaust ring mechanism used in a plasma processing apparatus according to a seventh embodiment of the present invention will be described. FIG. 8A is a diagram showing a plan view of the exhaust ring in the exhaust ring mechanism according to the seventh embodiment of the present invention as viewed from above, and FIG. FIG. 8C is a diagram showing an example of the arrangement of magnets and the direction of a magnetic field vector. FIG. 8C is a diagram for explaining the concept of magnetic field formation in the present embodiment. In the first to sixth embodiments described above, the exhaust ring The magnet is arranged directly below the bottom, and the process gas that has passed through the exhaust hole passes through the surface of the magnet. If the processing device is an etching device or the like, a corrosive gas is used as the process gas, and when the exhaust gas is exhausted, the magnet is corroded by the corrosive gas.

Therefore, in the present embodiment, the exhaust gas (corrosive gas) exhaust passage is configured not to directly touch the magnet. As shown in FIG. 8A, the exhaust ring 161 has a slit-shaped exhaust hole 161A that extends from the inside to the outside over the entire circumference. Arrange in a shape.

As shown in FIG. 8B, the ring-shaped inner peripheral side magnet base member 16 2 A and the outer peripheral side magnet base member 16 3 B, each of which is made of a conductor, are connected to the exhaust ring. It is mounted so as to fit into the exhaust ring cover part 161B provided at the lower end of the inner and outer peripheries of the 161.

Two ring-shaped magnets 163 A are attached to the inside and outside of the magnet base member 16 A, respectively, and two ring-shaped magnets are attached to the inside of the magnet base member 16 B. Magnet 1 6 3 B is installed. At this time, the ring-shaped magnet 1663A and the ring-shaped magnet 1663B are arranged so that the N pole and the S pole face each other, and the main surface direction (main direction) of the exhaust ring 161 is set. Magnetic field in the direction parallel to the plane). This is conceptually equivalent to arranging two U-shaped magnets as shown in Fig. 8C so that the N pole and the S pole face each other. This magnetic field traps the generated plasma in the above-mentioned plasma region, and transmits the non-plasma region to the non-plasma region. Acts to prevent plasma leakage.

According to the present embodiment, since the exhaust passage of the exhaust gas (corrosive gas) does not directly contact the magnet, it is possible to prevent the corrosion of the magnet, and further, due to the formed magnetic field, The generated plasma is confined in the plasma region, and the leakage of the plasma to the non-plasma region can be prevented. The same operation and effect as those of the first embodiment can be obtained.

Next, an exhaust ring mechanism used in a plasma processing apparatus according to an eighth embodiment of the present invention will be described. FIG. 9A is a diagram showing a plan view of the exhaust ring in the exhaust ring mechanism according to the eighth embodiment of the present invention as viewed from above, and FIG. 9B is a view showing the arrangement of magnets in the configuration of FIG. 9A. FIG. 9B is a diagram showing an example and the direction of a magnetic field vector (in the present embodiment, as shown in FIG.

17 1 has a slit-shaped exhaust hole 1771 A over the entire circumference, and has a plurality of radial exhaust holes extending from the inside to the outer periphery.

The group 171A is arranged, and a space 171B is provided between the groups. In the example shown in Fig. 9A, exhaust holes 1 7

1A is a group consisting of 5 to 7 tubes. Such an arrangement may be appropriately arranged according to the design and configuration of the exhaust efficiency and the like.

Then, as shown in FIG. 9B, in the magnetic field forming section, a plate-like magnet 174 is attached to a magnet base member 173 made of a conductor. The lower side of the space 17 1 B of the exhaust ring 1 Ί 1 described above is formed in a concave shape capable of accommodating the magnet 17 3 and covering the entire magnet. Space 1 7 1 Magnet to 1 B 1 7 3 By storing the gas, the exhaust gas flow path of the exhaust gas (corrosive gas) is configured not to directly touch the magnet.

According to the present embodiment, similarly to the above-described seventh embodiment, the corrosion of the magnet due to the corrosive gas exhausted can be prevented, and the generated plasma can be prevented from being generated by the generated magnetic field. It can be confined within the region and prevent the leakage of plasma into the non-plasma region. The same operation and effect as those of the first embodiment can be obtained.

Next, an exhaust ring mechanism used in a plasma processing apparatus according to a ninth embodiment of the present invention will be described.

FIG. 10A is a diagram showing a plan view of the exhaust ring in the exhaust ring mechanism according to the ninth embodiment of the present invention as viewed from above, and FIG. 10B is a magnet in the configuration of FIG. FIG. 2 is a diagram showing an example of the arrangement of the magnetic field and the direction of a magnetic field vector.

The exhaust ring 181 in the exhaust ring mechanism shown in FIG. 10A has a slit-shaped exhaust hole 181A arranged in the same manner as in the above-described eighth embodiment. As shown in FIG. 10B, the magnetic field forming part of the exhaust ring mechanism is provided on the lower surface side of each space 18 1 B provided between the groups of exhaust holes 18 A, as shown in FIG. 10B. The magnet 1 8 3 (permanent magnet or electromagnet) is provided.

In this configuration, the magnet 183 is formed in a shape having a taper like a trapezoid, and the magnetic field formed is such that the magnetic field lines are exhausted from the magnet 183 to the adjacent magnet 183. It is formed so as to pass through the ring 18 1 and bend in a convex shape. By this magnetic field, as in the above-described embodiments, the plasma region and the plasma ion Even if electrons try to pass through the exhaust holes 182, they are swirled by the action of the magnetic field and are confined in the plasma region without leaking to the non-plasma region.

Also, since the magnets 183 are located behind the space 181B (non-plasma area), the exhaust gas (corrosive gas) exhaust flow path does not directly touch the magnets. And

Next, a configuration in which the function of the exhaust ring mechanism used in the plasma processing apparatus according to the tenth embodiment of the present invention is applied to a deposit shield mechanism will be described.

Fig. 11A is a diagram showing an external configuration of a depot shield mechanism to which the function of the exhaust ring mechanism in each of the above-described embodiments is applied. Fig. 11B is a top view of the depot shield shown in Fig. 11A. Fig. 11C shows a plan view, Fig. 11C shows a side view of the deposit shield of Fig. 11A, and Fig. 11 D shows a part of the deposit shield where magnets are arranged in the radial direction. In each of the embodiments described above, the exhaust ring mechanism in which the magnetic field generated by the magnet is incorporated in the exhaust ring has been described. In the present embodiment, this magnetic field is applied around the lower electrode. A magnetic field is formed on a deposit shield that covers the inner wall of the processing chamber. In this example Is assumed to be a processing chamber having a cylindrical inside, so that it is cylindrical, but is not limited to this.

The deposit shield 19 is formed of a conductive material such as aluminum, and is supported by an outer peripheral ring portion 191B and a plurality of ring support portions 191C at an upper portion thereof. And an inner peripheral ring portion 1991A. This inner ring portion 1991A is fitted to the lower electrode when installed in the processing chamber, and has a height that is slightly lower than the mounting surface of the lower electrode. It has been.

A pair of ring magnets 1992A and a magnet are arranged on the inner wall side of the outer ring portion 1991B and the outer wall side of the inner ring portion 1991A so that the N pole and the S pole face each other. 192 B and are provided.

These magnets 19A and 19B (permanent magnets or magnetic stones) form a radial magnetic field equivalent to that shown in Fig. 5B described above, and generate plasma. It is possible to prevent the plasma from leaking into the non-plasma region by being confined in the plasma region. Also, in the present embodiment, the exhaust ring as in the first to ninth embodiments described above is used. If the device configuration cannot generate this magnetic field, the depot shield placed around the lower electrode has the function of forming a magnetic field, thereby realizing prevention of plasma leakage. And can be.

Next, a configuration in which the function of the exhaust ring mechanism used in the plasma processing apparatus according to the eleventh embodiment of the present invention is applied to a deposit shield mechanism will be described.

FIG. 12A shows the exhaust ring mechanism in each of the embodiments described above. Figure 12B shows the external configuration of the deposit shield mechanism to which the functions shown in Figs. 12A and 12B are applied. Fig. 12B shows the top view of the deposit shield shown in Fig. 12A. Fig. 12C shows Fig. 12A. FIG. 12D shows a partial cross-sectional configuration of a configuration in which magnets are arranged in the circumferential direction in the depot shield, as viewed from the side. In the above, the ring magnets were arranged so as to face each other in the radial direction to form a magnetic field in the radial direction. It is what forms. Also in this example, since the inside of the processing chamber is assumed to be cylindrical, the processing chamber is of course cylindrical, but is not limited to this.

The deposit shield 20 is formed of a conductive material such as aluminum, and has an outer peripheral ring portion and a plurality of circumferential ring members on its upper portion, similarly to the tenth embodiment. And an inner peripheral ring portion supported by the support portion. The inner peripheral ring portion is fitted to the lower electrode when installed in the processing chamber, and has a height that is equal to or slightly lower than the mounting surface of the lower electrode. .

A plate-like magnet 202 is provided on each of these ring support portions.

By these magnets 202, a circumferential magnetic field equivalent to that shown in FIG. 3A described above is formed, and the generated plasma is confined in the plasma region, and the plasma is transferred to the non-plasma region. Leakage can be prevented. Also in this embodiment, this magnetic field is formed in the exhaust ring as in the first to ninth embodiments described above. In the case of a device configuration that cannot be formed, a plasma shield can be prevented by providing a depot shield disposed around the lower electrode with a magnetic field forming function.

The magnet in each of the embodiments described above may be a permanent magnet, an electromagnetic magnet, or the like.

Further, magnets, electromagnets, and magnetic storage bodies may be affected by a temperature increase due to the impact of plasma, electrons, or the like, which may fluctuate the magnetic field and impair the original function. It may be covered by storing it in an aluminum case that has been processed. Also, the exhaust ring has been described as having a circular or slit-shaped exhaust hole, but is not limited to this, and can be applied to various exhaust holes such as an ellipse, a rectangle, and a rhombus.

Further, in each of the above embodiments, the parallel plate type plasma processing apparatus has been described as an example. However, if it is a type of plasma processing apparatus that exhausts gas through an exhaust ring, the exhaust gas of the present invention is used. Deposition shield mechanism can be applied.

Industrial applicability

The present invention includes: a lower electrode provided in a processing chamber and holding a wafer W; and an exhaust ring mechanism provided between the lower electrode and an inner wall of the processing chamber. The exhaust ring mechanism has an exhaust ring and a magnetic field forming unit that forms a magnetic field in the exhaust ring. Plasma leakage from a plasma region to a non-plasma region is caused by the formed magnetic field. Can be prevented.

Claims

The scope of the claims

1. An exhaust ring mechanism that comes into contact with a plasma region for performing plasma processing on an object to be processed in a processing chamber and forms an exhaust flow path for generated gas in the plasma region. ,

The exhaust ring mechanism is

An exhaust ring having a surface in contact with the plasma region, and a magnetic field forming unit that forms a magnetic field having magnetic lines of force substantially parallel to the surface direction of the exhaust ring.

2. In the exhaust ring mechanism according to claim 1,

The magnetic field forming section is formed such that at least a part of the magnetic field lines of the magnetic field passes through the inside of the exhaust ring.

3. In the exhaust ring mechanism according to claim 1,

The magnetic field forming unit is configured by a plurality of magnets or electromagnets disposed along each of the inner peripheral surface and the outer peripheral surface of the surface of the exhaust ring.

4. In the exhaust ring mechanism according to claim 2,

The magnetic field forming section is configured by a magnet or an electromagnetic stone disposed along each of the inner peripheral surface and the outer peripheral surface on the surface of the exhaust ring.

5. In the exhaust ring mechanism according to claim 1,

The magnetic field forming section is constituted by a plurality of magnets or electromagnets disposed along the inner peripheral edge portion and the outer peripheral edge portion of the lower surface of the exhaust ring, respectively.

6. The exhaust ring mechanism according to claim 2,

The magnetic field forming portion includes an inner peripheral portion of the lower surface of the exhaust ring and It is composed of a plurality of magnets or electromagnets respectively arranged along the outer periphery.

7. The exhaust ring mechanism according to claim 1,

The magnetic field forming section is constituted by a plurality of magnets or a plurality of electromagnetic stones radially arranged in the exhaust ring at predetermined circumferential intervals.

8. The exhaust ring mechanism according to claim 2,

The magnetic field forming unit is constituted by a plurality of magnets or a plurality of electromagnetic stones radially arranged in the exhaust ring at predetermined circumferential intervals.

9. In the exhaust ring mechanism according to claim 1,

The magnetic field forming section is constituted by a plurality of magnets or a plurality of electromagnets radially arranged on the lower surface side of the exhaust ring at predetermined circumferential intervals.

10. The exhaust ring mechanism according to claim 2, wherein the magnetic field forming portion includes a plurality of magnets or radially arranged on the lower surface side of the exhaust ring at predetermined circumferential intervals. It is composed of multiple electromagnets.

11. The exhaust ring mechanism according to claim 1, wherein the exhaust ring mechanism has a magnetic field sealing portion.

12. The exhaust ring mechanism according to claim 11, wherein the magnetic field sealing portion is made of a magnetic material.

1 3. A holder which is disposed in the processing chamber and holds the object to be processed;

Disposed between the holder and the processing chamber and exhausted A plasma processing apparatus comprising: an exhaust ring mechanism having holes; and performing a plasma process on the object to be processed, comprising:

The exhaust ring mechanism is

14. The plasma processing apparatus according to claim 13, wherein the magnetic field forming unit is formed such that at least a part of the magnetic field lines of the magnetic field pass through the inside of the exhaust ring.

15. The plasma processing apparatus according to claim 13, wherein the magnetic field forming unit includes a plurality of magnets disposed along each of an inner peripheral surface and an outer peripheral surface on the surface of the exhaust ring. Or, it is composed of an electromagnet.

16. The plasma processing apparatus according to claim 14, wherein the magnetic field forming unit includes a plurality of magnets disposed along each of an inner peripheral surface and an outer peripheral surface on the surface of the exhaust ring. Or, it is composed of an electromagnet.

17. The plasma processing apparatus according to claim 13, wherein the magnetic field forming unit includes a plurality of magnets or electromagnets disposed along inner and outer peripheral portions of the lower surface of the exhaust ring. It is composed of magnets.

18. The plasma processing apparatus according to claim 14, wherein the magnetic field forming unit includes a plurality of magnets or electromagnets disposed along an inner peripheral portion and an outer peripheral portion of the lower surface of the exhaust ring. It is composed of magnets.

19. The plasma processing apparatus according to claim 13, wherein the magnetic field forming unit includes a plurality of magnets or a plurality of magnets radially arranged in the exhaust ring at predetermined circumferential intervals in the exhaust ring. It is composed of electromagnetic stones.

20. The plasma processing apparatus according to claim 14, wherein the magnetic field forming unit includes a plurality of magnets or a plurality of electromagnetic waves radially arranged in the exhaust ring at predetermined circumferential intervals in the exhaust ring. It is composed of stone.

21. The plasma processing apparatus according to claim 13, wherein the magnetic field forming unit includes a plurality of magnets or a plurality of electromagnetic waves radially arranged in the exhaust ring at predetermined circumferential intervals in the exhaust ring. It is composed of stone.

22. The plasma processing apparatus according to claim 14, wherein the magnetic field forming unit includes a plurality of magnets or a plurality of magnets radially arranged on the lower surface side of the exhaust ring at predetermined circumferential intervals. It is composed of multiple electromagnets.

23. The plasma processing apparatus according to claim 13, wherein the exhaust ring mechanism has a magnetic field sealing portion.

24. In the plasma processing apparatus according to claim 23, the magnetic field sealing portion is made of a magnetic material.

25. Within the processing chamber, the processing chamber contacts the plasma region for performing plasma processing on the object to be processed, and contacts the exhaust gas flow path of the generated gas in the plasma region. A depot shield mechanism that protects the inner wall,

The above depot shield is A magnetic field forming unit that forms a magnetic field having lines of magnetic force substantially parallel to the direction of the electrode surface that forms the plasma at an end in contact with the plasma region.

26. In the deposit shield mechanism according to claim 25, the magnetic field forming section is formed so that at least a part of the magnetic field lines of the magnetic field passes through the upper portion of the deposit shield.

27. The deposit shield mechanism according to claim 25, wherein the magnetic field forming section includes a plurality of magnets or a plurality of magnets disposed along respective inner and outer peripheral portions provided on the upper portion of the depot shield. Is constituted by the electromagnet.

28. The deposit shield mechanism according to claim 26, wherein the magnetic field forming portion is constituted by a plurality of magnets or a plurality of electromagnets arranged at a predetermined interval along a circumferential direction in an upper portion of the deposit shield. You.