JPH06267903A - Plasma device - Google Patents

Abstract

PURPOSE:To uniformize the density of plasma in a plasma device, wherein the plasma is generated in a treating chamber by means of high-frequency induction and a treatment is performed on a material to be treated in the treating chamber. CONSTITUTION:A plasma device has a chamber constituted for performing a plasma treatment on a wafer W on a placement base 4 and is provided with an antenna for forming an induction field in the vicinity of the wafer W by feeding a high frequency from a high-frequency power supply 21 provided on the outside of this chamber 2 via an upper wall 3, which is an insulator, and a thin plate 24, which is arranged in such a way that at least one part of the plate 24 is superposed on the antenna and consists of a normal magnetic material. Thereby, a plasma generating region is displaced and the density of plasma can be uniformized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma device.

[0002]

2. Description of the Related Art For example, a manufacturing process of a semiconductor device such as an LSI will be described as an example. In order to promote ionization and a chemical reaction of a processing gas in various processes such as etching, ashing, CVD and sputtering,
Plasma devices that generate plasma are widely used, but in recent years, as the pattern to be applied to an object to be processed such as a semiconductor wafer (hereinafter referred to as a “wafer”) has become finer, the energy density distribution of the plasma and the plasma From the viewpoint of adjusting the bias potential between the susceptor and the susceptor with higher accuracy and reducing heavy metal contamination from the electrodes, a so-called high-frequency induction type plasma device using a spiral antenna has been proposed.

For example, European Patent Publication No. 379828.
As disclosed in Japanese Patent Publication No. 2000-331, the wafer mounting table and the facing portion (generally the upper wall portion) of the hermetically sealed processing container (chamber) are made of an insulating material such as quartz glass, and the outer wall surface has a spiral shape. The antenna is fixed and a high-frequency current is passed through the antenna to create a high-frequency electromagnetic field in the processing container, whereby the processing gas supplied into the processing container is ionized and plasma is generated. In the plasma apparatus using such a system, plasma is generated in the space inside the processing container located directly below the antenna.

[0004]

However, the above-described conventional plasma device has the following problems.
That is, generally, the plasma generation density is highest at the position corresponding to the center between the center and the outside in the radial direction of the spiral antenna, and the plasma density becomes lower toward the inside and outside. ing. That is, the plasma density is not uniform. Therefore, the uniformity and reproducibility of the plasma treatment have not been sufficient. Further, the method for adjusting the plasma density has not been sufficiently disclosed.

The present invention has been made in view of the above points, and in the high frequency induction method, the uniformity of the plasma density in the vicinity of the surface to be processed of the object to be processed is improved to provide excellent uniformity and reproducibility in the plasma processing. Another object of the present invention is to provide a plasma device capable of adjusting the plasma density.

[0006]

In order to achieve the above object, according to the present invention, the following plasma device is provided. First, according to claim 1, a processing chamber configured to perform a plasma process on an object to be processed on a susceptor, and a portion outside the processing chamber corresponding to the object to be processed are provided via an insulator. And a paramagnetic member disposed so as to form an induction electric field in the vicinity of the object to be processed by supplying high frequency power, and a paramagnetic member arranged so that at least a part thereof overlaps the induction means. A featured plasma device is provided.

In such a case, the guiding member constituting the guiding means may be formed in a single spiral shape as described in claim 2, and as described in claim 3, a single loop. You may form in a shape.

Further, as described in claim 4, the guiding means is constituted by two or more guiding members,
Each guide member may be arranged in a concentric manner as a single spiral, or as described in claim 5, each guide member may be arranged in a concentric manner as a single loop. Good.

When the guiding means is composed of two or more guiding members as described above, a single spiral guiding member and a single loop-shaped guiding member are used as described in claim 6. It may be a combination.

As described above, when there are a plurality of induction members, the high frequency power supplied to each induction member may be independently controlled as described in claim 7.

Further, in each of the plasma devices constructed as described above, the paramagnetic member may be plate-shaped as described in claim 8, and further, as described in claim 9, The paramagnetic member may be made of copper.

On the other hand, according to a tenth aspect of the present invention, an insulating material is provided in a processing chamber configured to perform plasma processing on the object to be processed on the susceptor, and a portion outside the processing chamber corresponding to the object to be processed. And a guiding means for forming a guiding electric field in the vicinity of the object to be processed by supplying high frequency power, the guiding means being a spiral guiding member having a space region in the center thereof. Provided is a plasma device characterized in that it is configured.

In this case, as described in claim 11,
The guiding means may be constituted by a spiral guiding member having a pitch different between the outer portion and the central portion.
In addition, as described in claim 12, the above-mentioned claim 1
In the plasma apparatus described in 11, the high frequency applying means for applying a high frequency bias to the object to be processed may be further provided.

On the other hand, according to a thirteenth aspect of the present invention, it comprises a plasma generating section and a plasma processing section, and the plasma flow generated in the plasma generating section is introduced into the processing chamber of the plasma processing section, whereby the processing chamber of the plasma processing section is introduced. In the plasma device for performing a plasma process on an object to be processed mounted and fixed on a susceptor, the plasma generating unit is placed in the process chamber through an insulating member by applying a high frequency current. Antenna means for forming an alternating electric field,
A first magnetic field forming unit that is arranged so as to surround the plasma generating unit and forms a static magnetic field in a direction orthogonal to the alternating electric field is provided, and by appropriately adjusting the alternating electric field and the static magnetic field, It is configured to form an electron cyclotron resonance region in the processing chamber, and further, in the plasma processing unit, the plasma flow introduced into the processing chamber is provided to surround the processing chamber with respect to the object to be processed. There is provided a plasma device characterized in that a second magnetic field forming means for shaping and holding the same is provided.

In this case, as described in claim 14, the insulating member forms a plasma generating chamber communicating with the processing chamber, and the antenna means makes at least one turn around the outer peripheral portion of the plasma generating chamber. It may be arranged.

According to a fifteenth aspect, the insulating member constitutes at least a part of a wall portion of the processing chamber,
The antenna means may be configured as a single spiral antenna arranged substantially parallel to the outer wall surface of the insulating member.

Further, as described in claim 16, the insulating member constitutes at least a part of a wall portion of the processing chamber, and the antenna means is arranged substantially parallel to an outer wall surface of the insulating member. The antenna members may be configured as described above, and each antenna member may be a spiral antenna and may be arranged concentrically. Further, in this case, as described in claim 17, the antenna members may be loop-shaped antennas and arranged concentrically.

Further, as described in claim 18, two kinds of the antenna member, that is, a spiral antenna and a loop antenna, are prepared, and these are appropriately combined to arrange them concentrically. Good.

When there are a plurality of antenna members in each of the plasma devices, the high frequency current applied to each of the antenna members is as described in claim 19.
You may comprise so that each may be controlled independently.

Furthermore, as described in claim 20,
A high-frequency current having a frequency of 100 MHz or less is passed through the antenna means, and a magnetic field having a magnetic flux density corresponding to the frequency is formed by the first magnetic field forming means so that the ECR is performed.
The condition may be achieved.

On the other hand, according to a twenty-first aspect of the present invention, there is provided a processing chamber airtightly configured to perform plasma processing on the object to be processed mounted and fixed on the susceptor, and at least a wall portion of the processing chamber. A part of the insulating member is an induction field forming means capable of forming a rotating electric field in a desired region in the processing chamber by applying a high frequency current from the first high frequency power source to the outer surface of the insulating member. A magnetic pole material is disposed outside the processing chamber and in the vicinity of the induction electric field forming means, and a cross-sectional area of the magnetic pole material cut at a plane substantially parallel to the processing surface of the object to be processed is at least It is made larger than the area of the processing surface, and the thickness of the magnetic pole material is set to such a degree that the influence of the demagnetizing field excited by the applied high frequency current can be ignored, and the susceptor is independent of the first high frequency power supply. do it Characterized in that it is configured to be able to apply a bias potential by the second high-frequency power source capable of settling, the plasma apparatus is provided.

In such a case, as described in claim 22, the induction electric field forming means may be a loop antenna having a loop of at least one turn.

Further, the induction electric field forming means is composed of two or more antenna members, and as described in claim 23, each antenna member is a loop antenna, and these are arranged concentrically. May be.

When the induction electric field forming means is composed of two or more antenna members, the high frequency current applied to each of the antenna members is independently controlled as described in claim 24. You may comprise.

On the other hand, the magnetic pole material in the plasma device having the above structure may be made of soft ferrite as described in claim 25.

According to a twenty-sixth aspect of the present invention, the thickness of the magnetic pole material portion that forms a magnetic field that acts on a region where the plasma density distribution is desired to be relatively increased, and the magnetic field that acts on other regions are formed. The magnetic pole material may be thicker than the thickness of the magnetic pole material.

[0027]

According to the present invention, since the induction means for forming an induction electric field in the vicinity of the object to be processed by the supply of the high frequency electric power and a part of the paramagnetic material are overlapped with each other, the generated magnetic flux is the paramagnetic material. It does not penetrate the body. By that,
It is possible to displace the generation region of the generated plasma. In such a case, the guiding member forming the guiding means has a single spiral shape as described in claim 2 or claim 3
In the case of a single loop as described in 1., a relatively uniform plasma is generated.

Further, as described in claim 4, the guiding means is constituted by two or more guiding members, each guiding member is formed as a single spiral, and these are arranged concentrically. As described above, even when these are arranged concentrically as a single loop, the magnetic field strength of the induced concentric alternating electric field can be adjusted. In such a case, as described in claim 6, even if a single spiral guide member and a single loop-shaped guide member are combined, the same operational effect can be obtained, and more various effects can be obtained. Adjustment is possible.

When a plurality of induction members are provided and the high frequency power supplied to each induction member is independently controlled, the induction members are induced by the individual induction members. Since the strength of the alternating electric field generated can be adjusted, extremely fine and wide range plasma density control can be performed.

In each of the plasma devices configured as described above, when the paramagnetic member is plate-shaped as described in claim 8, it is easy to employ as a device structure in terms of space and The penetration of magnetic flux can be blocked evenly. Further, as described in claim 9, when the paramagnetic member is made of copper, since the conductivity is good, it is preferable for generating an eddy current that obstructs the magnetic flux.

According to the tenth aspect of the present invention, the induction means for forming an induction electric field in the vicinity of the object to be processed by supplying the high frequency power is constituted by a spiral induction member having a space region in the center thereof. Therefore, the number of magnetic fluxes vertically penetrating the central portion is reduced, the magnetic field strength of the induced alternating electric field is reduced, and the plasma generation region is displaced outward in the radial direction. Therefore, by utilizing this, it becomes possible to make the plasma density uniform.

In this case, as described in claim 11,
If the guiding means is composed of a spiral guiding member having a different pitch between the outer portion and the central portion, it is possible to make the alternating electric field induced in the outer portion and the central portion relatively sparse and dense. This can be utilized to make the plasma density uniform.

According to a twelfth aspect of the invention, in the plasma apparatus according to the first to eleventh aspects of the invention, when the high frequency applying means for applying a high frequency bias to the object to be processed is further provided, It is possible to further accelerate the ions.

On the other hand, according to a thirteenth aspect, an alternating electric field is formed in the processing chamber through the insulating member by applying a high frequency current to the antenna means installed in the plasma generating section. As described above, the plasma device according to the thirteenth aspect is configured to achieve the ECR condition without using the microwave of the ultra-high frequency. Therefore, the frequency region to be used is set to a relatively low region, for example, 100.
It can be set below MHz. Therefore, even if the magnetic flux density of the static magnetic field formed in the direction orthogonal to the alternating electric field by the antenna means is reduced, the ECR condition can be achieved, and the first magnetic field forming means for that purpose can be miniaturized. You can Also, a small magnetic field is sufficient to achieve the ECR condition, so the influence of the divergent magnetic field on the plasma flow can be minimized.

Further, in the thirteenth aspect, the second magnetic field forming means is provided so as to surround the processing chamber. Therefore, the expansion area of the plasma flow introduced into the processing chamber is expanded to a planar shape near the object to be processed, and a uniform plasma flow is maintained in the processing area, and the direction of the plasma flow is directed to the processing surface of the object to be processed. It is possible to orient vertically.

According to claim 14, the plasma state can be controlled by the number of turns of the antenna means.
For example, if a cylindrical plasma generation chamber is formed by an insulating member and the outer peripheral portion of the plasma generation chamber is surrounded by an antenna means, a uniform alternating electric field can be formed at substantially the center of the plasma generation chamber. Since the plasma generation unit and the plasma processing unit can be separated, it becomes possible to set and control separate parameters for the plasma generation condition and the plasma processing condition, and to perform more highly accurate plasma processing. You can

According to a fifteenth aspect, at least a part of the wall portion of the processing chamber, for example, the upper surface is constituted by the insulating member,
The spiral antenna is arranged substantially parallel to the outer wall surface of the insulating member. With this configuration, the ECR region can be directly formed in the vicinity of the surface of the inner wall of the insulating member, so that the device can be simplified and downsized. According to the sixteenth aspect, since two or more spiral antennas in that case are concentrically arranged, it is possible to control the plasma density in a wider range. Similar effects can be obtained when the antenna members are arranged in a loop and are arranged concentrically as in the seventeenth aspect.

When the spiral antenna and the loop antenna are combined as described in claim 18, it is possible to control the plasma density in a wider range.

If the high frequency current applied to each of the antenna members is independently controlled as described in claim 19, it is possible to control the plasma density more finely and in a wide range.

According to a twentieth aspect, a high frequency current having a frequency of 100 MHz or less is passed through the antenna means, and a magnetic field having a magnetic flux density corresponding to the frequency is formed by the first magnetic field forming means. If the conditions are satisfied, the magnetic flux density of the static magnetic field can be reduced, and the entire device can be simplified and downsized.

According to the twenty-first aspect, a high-frequency current is applied from the first high-frequency power source to the induction electric field forming means to form a rotating electric field in the processing chamber, and the rotating electric field accelerates the electrons to satisfy the plasma generation condition. To be achieved. As described above, according to the twenty-first aspect, it is possible to generate the plasma without using the electrode, and thus it is possible to reduce heavy metal contamination of the product due to the electrode material.

When the induction electric field forming means is configured as a loop antenna as in claim 22, a more uniform rotating electric field can be formed, so that plasma excellent in in-plane uniformity can be generated in the processing chamber. Can be generated.

According to the twenty-third aspect, since it is composed of two or more antenna members, it is possible to adjust the plasma density in a wider range, and to generate a plasma having excellent in-plane uniformity in the processing chamber. be able to. When the high frequency current applied to each antenna member is independently controlled as in the twenty-fourth aspect, it is possible to control the plasma density more finely and in a wide range.

According to the twenty-fifth and the twenty-sixth aspects, for example, soft ferrite is used for the magnetic pole material, and the thickness of the magnetic pole material portion for forming a magnetic field acting on a region where the plasma density distribution is desired to be relatively increased, The magnetic field in the processing chamber is adjusted by adjusting the shape of the magnetic pole material so as to be thicker than the thickness of the magnetic pole material portion that forms the magnetic field acting on the region of It can be adjusted freely. Further, at least by forming a cross-sectional area of the magnetic pole material cut in a plane substantially parallel to the processing surface of the object to be processed is wider than the processing surface of the object to be processed,
It is possible to irradiate a plasma flow having a desired density distribution over the entire processed surface of the object to be processed.

When a high-frequency current is passed through the dielectric electric field forming means, a demagnetizing field is formed in the magnetic pole material arranged near the dielectric electric field forming means, which may affect the magnetic field in the processing chamber. This can be solved by making the material have a certain thickness or by making the magnetic path longer. If soft ferrite is used as in the twenty-fifth aspect, it is easy to adopt such a form.

[0046]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 and FIG. 2 are perspective views and sectional views schematically showing the construction of a plasma apparatus according to a first embodiment of the present invention. As shown in FIG. 1, in the chamber 2 in which the processing chamber of the plasma apparatus 1 is formed, the bottom wall and the side wall are made of metal such as aluminum, and the upper wall 3 is made of an insulator such as quartz glass ( It is configured as a cylindrical closed container made of silica glass) or a ceramic material. When transparent quartz glass is used as the upper wall 3, it is possible to visually recognize the light emission state of plasma in the chamber 2.

A disk-shaped or column-shaped mounting table (susceptor) 4 is arranged at the center of the bottom surface of the chamber 2, and a wafer W, for example, is mounted as an object to be processed on the upper surface of the mounting table 4. ing. The mounting table 4 is made of, for example, aluminum whose surface is anodized. When the plasma device 1 is configured as an etching device,
For example, a frequency of 13.56 for etching is provided on the mounting table 4 through a capacitor 5 as a matching circuit.
A high frequency power source 6 of MHz is connected.

Cooling water is supplied to the inside of the mounting table 4 from a cooling water supply unit (not shown) in order to prevent heating by high frequency. By providing such a high-frequency power source 6 and appropriately applying a high-frequency bias to the mounting table 4 in accordance with the processing gas and gas pressure used, ions in the plasma flow are accelerated and the ion flow is made uniform. Is possible.

On the upper surface of the mounting table 4, a focus ring 7 made of quartz and surrounding the wafer W to be processed is provided so as to be higher than the surface to be processed of the wafer. The focus ring 7 has a function of concentrating the plasma generated above the mounting table 4 on the surface to be processed of the wafer W to enhance the plasma processing efficiency. For example, in the case of etching processing, the etching rate is increased. Has the effect of increasing Also this focus ring 7
Also has a function of preventing dust from being generated by etching an exposed portion of the mounting table 4 made of aluminum on which the wafer W is not mounted by plasma.

An electrostatic chuck 10 is provided on the wafer holding surface of the mounting table 4. The electrostatic chuck 10 has a structure in which a copper foil 11 as an electrode is covered with an insulating film, for example, polyimide resin, and has a function of accurately attracting and holding the wafer W by electrostatic force. This electrostatic chuck 10
A DC power supply 12 is connected to this DC power supply 12
When a voltage of, for example, 2 kV is applied to the electrostatic chuck 10, the wafer W as the object to be processed is attracted and held by the electrostatic chuck 10.

A gas introduction port 13 is provided on the upper side surface of the above-mentioned chamber 2, and the gas supply pipe 1 is provided in the gas introduction port 13.
4 is connected. Then, the processing gas is supplied from the separately provided gas supply source 15 into the chamber 2 through the gas supply pipe 14. In this case, the supplied processing gas differs depending on the type of processing. For example, in the case of etching processing, etching gas such as CHF ₃ or CF ₄ is supplied. Although one gas supply source 15 and one gas supply pipe 14 are shown in the illustrated example, the number of gas supply sources and gas supply pipes corresponding to the type of processing gas should be connected to the chamber 2. May be.

A gas exhaust port 16 is provided in the lower portion of the side surface of the above-mentioned chamber 2, and a gas exhaust pipe 17 is connected to the gas exhaust port 16. The gas exhaust pipe 17 is connected to an exhaust system 18 including a vacuum pump,
The inside of the chamber 2 can be evacuated to a predetermined degree of reduced pressure.

Further, a spiral high-frequency antenna 20 as a guide member is provided on the outer wall surface of the upper wall 3 of the chamber 2 so as to face the wafer W mounted on the mounting table 4 in the chamber 2. It is arranged. The antenna 20 is made of a linear or tubular conductive material, and is preferably made of copper having excellent cooling characteristics. Between the inner terminal 20a and the outer terminal 20b of the antenna 20, for example, the frequency is 13.56 from a high frequency power source 21 for plasma generation via a capacitor 22 as a matching circuit.
The high frequency power of MHz is applied. With such a configuration, a high-frequency current iRF flows through the antenna 20, and an induction electric field is formed in the space inside the chamber 2 immediately below the antenna 20 as described later, thereby generating plasma of the processing gas. The high frequency power supplies 6 and 21 described above are controlled by the controller 23.

In the first embodiment, a circular thin plate 24 made of paramagnetic metal such as copper is interposed between the center of the antenna 20 and the upper wall 3 made of quartz glass. The diameter of the thin plate 24 is appropriately selected and set according to the shape and size of the antenna 20, the output power of the high frequency power supply 21, the diameter of the wafer W, the distance between the antenna 20 and the wafer W, and the like. As will be described later, the thin plate 24 adjusts the alternating magnetic field B in the space inside the chamber 2 immediately below the antenna 20, and the alternating electric field E induced therein is adjusted.
Is adjusted, and as a result, the plasma is diffused, so that the plasma density is made uniform near the surface of the wafer W.

The plasma apparatus 1 according to the first embodiment is configured as described above. Next, the plasma generation and plasma processing in the plasma apparatus of this embodiment will be described with reference to FIG. The wafer W, which is the object to be processed, is transferred from a load lock chamber (not shown) adjacent to the chamber 2 into the chamber 2 that has been evacuated to a reduced pressure atmosphere, for example, 10 ⁻⁶ Torr, and the mounting table in the chamber 2 It is placed on the surface of the electrostatic chuck 4, and is attracted and held by the electrostatic chuck 10.
Then, a predetermined processing gas such as CHF ₃ or CF ₄ is introduced into the chamber 2 into the wafer W through the gas supply pipe 14. At this time, the pressure in the chamber 2 is, for example, 1
Adjusted to 0 ^-3 Torr.

In this state, a high frequency voltage from the high frequency power source 21 is applied to the antenna 20. By applying this high frequency voltage, the high frequency current iRF is applied to the antenna 24.
Flow, an alternating magnetic field B is generated around the conductor of the antenna 20, and most of the magnetic flux passes through the center of the antenna in the vertical direction to form a closed loop. The alternating magnetic field B induces an alternating electric field E in a substantially concentric circular direction immediately below the antenna 20, and the electrons accelerated in the circumferential direction by the alternating electric field E collide with neutral particles of the processing gas. By doing so, the gas is ionized and plasma is generated.

The plasma thus generated just below the antenna 20 has the highest plasma density at a position corresponding to an intermediate portion between the center and the outer side in the radial direction of the antenna 20, as schematically shown in FIG. Higher, the plasma density becomes lower toward the inside and outside. However, in this embodiment, since an eddy current that prevents the penetration of the magnetic flux B flows in the circular thin plate 24, the alternating magnetic field B
Is hard to pass through the central portion of the antenna, and passes outside the magnetic flux B'indicated by the dotted line when the thin plate 24 is not present. Therefore, the plasma generation region P directly below the antenna is displaced outward in the radial direction from the plasma generation region P ′ shown by the broken line when the thin plate 24 is not provided.

Without the thin plate 24, the plasma diffuses from the high density region to the low density region and the plasma density is leveled in the vicinity of the wafer W. As a result, as shown by Pd 'in FIG.
The plasma density near the center of the wafer W is higher than the plasma density near the outer peripheral edge of the wafer. Therefore, the wafer W
The surface is treated unevenly.

On the other hand, when the thin plate 24 is present, as described above, the plasma generation region P which is displaced outward in the radial direction is larger than the plasma generation region P'indicated by the broken line when the thin plate 30 is not present. Since the plasma is diffused in the radial direction and the downward direction, the plasma density is leveled near the wafer W, and near the surface of the wafer W, as shown by Pd in FIG. To be done.
Therefore, the ions, electrons, and other active species contained in the plasma are uniformly supplied or irradiated to the entire surface of the semiconductor wafer W, and the predetermined plasma processing is uniformly performed on the entire surface of the wafer.

For example, in plasma etching, gas molecules excited to an active state by plasma chemically react with a substance to be processed on the wafer surface, the reaction product is vaporized, and the wafer surface is scraped off. Further, in plasma CVD, gas molecules excited to the active state by plasma react with each other and the reaction product is deposited on the surface of the wafer to form a CVD film. As described above, in any of the plasma treatments, when the plasma device according to the first embodiment of the present invention is used, the plasma acts on the entire surface of the wafer W with a uniform density, and thus the plasma is evenly distributed on the wafer surface. The processing is performed.

When the predetermined processing for the wafer W is completed in the chamber 2 as described above, after the residual processing gas and reaction products in the chamber 2 are sufficiently exhausted by the exhaust system 18, the transfer arm (not shown). Then, the wafer W on the mounting table 4 is unloaded to the load lock chamber, and the process ends.

As described above, in the plasma device 1 of the first embodiment, the thin plate 24 as a paramagnetic metal member arranged so as to overlap a part of the antenna 20 as an induction member (for example, the central portion of the antenna) has a magnetic flux. By weakening the penetration of the thin plate 24, the alternating electric field E is weakened at the position of the inner space of the chamber 2 corresponding to the thin plate 24, and the plasma generation density is also lowered. Therefore, when the thin plate 24 is provided in the central portion of the antenna 20, the plasma generation region P immediately below the antenna is displaced radially outward, and as a result, the plasma density on the surface (processed surface) of the wafer W is increased. Be homogenized. As a result, it is possible to perform uniform and reproducible plasma processing on the wafer W that is the object to be processed.

In the first embodiment, the antenna 20 as the guiding member has the spiral shape as described above, but the present invention is not limited to this and, for example, as shown in FIG. 4, a ring having a single loop shape. A terminal 31 at each end
The antenna 31 having a and 31b may be used. Also in the case of the antenna 31 formed in the ring shape as described above, an alternating electric field is formed by the same mechanism as in the case of the spiral shape,
A relatively uniform plasma is formed.

Further, as shown in FIG. 5, the antenna 35 may have a shape in which the central portion of the spiral is cut off. In these cases as well, the plasma density is made more uniform by the above-described action of the thin plate 24 which is a paramagnetic metal member. Note that FIG.
In the case of the antenna 35 shown in FIG. 1, the diameter of the space area in the central part is determined by
The power is appropriately selected and set according to the output power of the high frequency power supply 21 connected to 35b, the diameter of the wafer W as the object to be processed, the distance between the antenna 35 and the wafer W, and the like.

The paramagnetic metal member is not limited to the circular thin plate 24 as described above. Further, the paramagnetic metal member may be arranged at a place other than the central portion of the antenna as long as it is arranged in the vicinity of the antenna as the guiding member, and if necessary, it may be arranged at a plurality of portions (for example, the central portion of the antenna and the outer circumference of the antenna). Section). Further, the paramagnetic metal member according to the present invention may be arranged so as to overlap the antenna.

Next, a second embodiment of the present invention will be described. In this embodiment, the same basic apparatus configuration as a plasma device such as a chamber is used as in the first embodiment. However, in this second embodiment, the plasma density is adjusted by changing the state of the spiral antenna without using a paramagnetic metal member. That is, in the second embodiment, in the plasma device 1 shown in FIGS. 1 and 2, the thin plate 24 is removed,
Moreover, the antenna 40 shown in FIG. 6 is used instead of the antenna 20.

In FIG. 6, the antenna 40 as a guiding member is shown.
Has a spiral shape with a spatial region in the center. As described above, in the spiral antenna 40 having the spatial region in the central portion, the number of magnetic fluxes vertically penetrating the central portion of the antenna decreases, so that the magnetic field strength of the alternating electric field induced by the diameter decreases, Similar to the first embodiment described above, the plasma generation region is displaced outward in the radial direction. Therefore, the plasma density is made uniform by the same operation as in the first embodiment. In this case, since the paramagnetic metal member used in the first embodiment does not exist, the diameter R of the space area in the central portion of the antenna needs to be larger than the diameter of the antenna 35 in FIG. A diameter corresponding to the diameter of the wafer is selected.

However, also in the case of the antenna 40 shown in FIG. 6, the diameter of the space area in the central portion is determined by the number of spirals (the number of turns) of the antenna 40, the output power of the high frequency power source 21 connected to the terminals 40a and 40b, Of course, it is appropriately selected according to the diameter of the wafer to be processed, the distance between the antenna 40 and the wafer, and the like.

In the example shown in FIG. 7, in the spiral (spiral) antenna 45, the pitch of the antenna conductors is changed in the radial direction so that the antenna outer portion is dense and the antenna central portion is sparse. . According to such a spiral structure, the concentric alternating electric field induced immediately below the antenna is relatively small in the inner peripheral portion (central portion), so that the plasma generation region is also shifted radially outward, and the The same effect as that of the first embodiment is obtained, and the plasma density is made more uniform.

Next, the third embodiment will be described. In this third embodiment, the chamber and the other basic device configuration as a plasma device is the same as that of the first embodiment, but the induction is performed. Two antennas as members,
The high-frequency voltage is concentrically provided and the high-frequency voltages supplied to these two antennas are independently controlled. That is, in the third embodiment, in the plasma device 1 shown in FIGS. 1 and 2, the thin plate 24 is removed and the antenna 20, the high frequency power source 21 and the capacitor 22 are replaced with the ring-shaped antenna 51 shown in FIG. 52, and a high-frequency power source for applying high-frequency power to these, and the like.

In FIG. 8, ring-shaped antennas 51 and 5 are provided.
2 are provided concentrically, preferably on the same plane, and a first high frequency power supply 54 is connected between the terminals 51a and 51b of the outer antenna 51 via a capacitor 53 as a matching circuit. On the other hand, a second high-frequency power source 56 is connected between the terminals 52a and 52b of the inner ring-shaped antenna 52 via a capacitor 55 as a matching circuit.

The first and second high frequency power supplies 54, 5
6 supplies independent 1st and 2nd high frequency electric power to the outer and inner ring-shaped antennas 51 and 52, respectively, with the same frequency (for example, 13.56 MHz) and the same phase. When the antenna is basically arranged at the same position as in FIGS. 1 and 2, the second high frequency power is selected to be lower than the first high frequency power.

As a result, the outer ring-shaped antenna 5
1, a relatively large high frequency current iARF flows, and a relatively small high frequency current iBRF flows through the inner ring-shaped antenna 52. In this case, the plasma generation region P in the chamber 2 immediately below the antenna has the same high-frequency current iRF as the single antenna 20 shown in FIG.
Is shifted to the outside of the plasma generation region P'when the gas flows, the plasma density can be made uniform by the same action as in the first embodiment.

In this case, as shown in FIG. 8, the outer ring-shaped antenna 51 and the inner ring-shaped antenna 5 are arranged.
Wafer W as the object to be processed at a position corresponding to
It is preferable to arrange the antennas so that the positions are located in order to make the plasma density more uniform. Further, the number of ring-shaped antennas is not limited to two as shown in FIG. 8 and may be three or more.

Further, by constructing the antenna as the guiding member in this way, the high frequency power can be set independently for the inner antenna and the outer antenna, so that the plasma generation region can be controlled more finely and widely. . By providing a power distribution circuit between the high frequency power supply and both antennas 51 and 52, the first and second high frequency power supplies 51 and 52 can be shared by one high frequency power supply.

FIG. 9 shows an example in which two spiral antennas 61 and 62 are concentrically arranged. That is,
A spiral antenna 62 is provided inside a spiral antenna 61, and corresponding high frequency power supplies 65 and 66 are connected via capacitors 63 and 64, respectively. Also in this case, the same effect as the example shown in FIG. 8 can be obtained. The number of turns of each spiral antenna 61, 62 can be arbitrarily selected according to the output of each high-frequency power source, the diameter of the wafer to be processed, the distance between the antenna and the wafer, and the like.

In FIG. 10, a spiral antenna 71 is provided.
Although the ring-shaped antenna 72 is concentrically arranged, the same effect can be obtained in this case. The ring-shaped antenna 72 may be inside as shown in FIG. 10, or the ring-shaped antenna 72 may be outside. Corresponding high frequency power sources 65 and 66 are connected to the antennas 71 and 72 via capacitors 63 and 64, respectively.

Further, in the examples of FIGS. 8 to 10, the paramagnetic metal member used in the first embodiment may be used together. In that case, the plasma can be adjusted by both the high frequency power and the paramagnetic metal.

Next, the fourth embodiment will be described.
The embodiment is an example applied to an ECR plasma etching apparatus. First, the device configuration of a plasma device 81 according to the fourth embodiment will be described based on FIGS. 11 to 14.

The plasma apparatus 81 is composed of a plasma generating section A and a plasma processing section B, as schematically shown in FIG. The plasma generating part A has, for example, a cylindrical quartz tube 82 having a dome-shaped top portion, an antenna means 83 surrounding the quartz tube 82, and an electromagnetic wave arranged above the antenna means 83 so as to surround the quartz tube 82. And a coil 84.

The antenna means 83 is connected to the first high frequency power source 86 via the matching box 85 and can apply a high frequency current in response to a command from the controller 87. Further, the electromagnetic coil 84 is connected to a power source 88 and is configured to be able to excite a desired static magnetic field in response to a command from the controller 87. In addition, a first process gas such as an inert gas such as argon can be introduced from the first gas source 89 to the top of the dome portion of the quartz tube 82 via a mass flow controller (not shown). A conduit 90 is attached.

As shown in detail in FIG. 12, the antenna means 83 is composed of an upper ring member 83a, a lower ring member 83b, and a connecting member 83c for connecting both rings. An alternating electric field can be formed in the cylindrical quartz tube 82 by applying a desired high-frequency current through the matching box 85, as shown by the arrow in FIG. The structure of the antenna is not limited to the above shape as long as it can form an alternating electric field in a desired region.

Further, as apparent from FIGS. 12 and 13, the electromagnetic coil 84 is arranged above the antenna means 83 so as to surround the cylindrical quartz tube 82. Note that in FIG. 12, in order to facilitate understanding of the structure, the electromagnetic coil 84 is shown in a state in which approximately half is cut away. As shown by the arrow in the plan view of FIG. 13, by exciting the electromagnetic coil 84 by the power supply 88, the direction orthogonal to the alternating electric field, that is, in the vertical direction (axial direction of the cylindrical quartz tube) in the illustrated example, is downward. It is configured to create a static magnetic field toward.

As will be described later, the size and output of the quartz tube 82, the antenna means 83, and the electromagnetic coil 84, which constitute the plasma generating portion, are about 20 to 20 mm above the reaction surface of the wafer W to be processed. Around 30 cm, that is, FIG.
In the above example, adjustment is made so that an ECR region (Ec) is formed in the vicinity of the connecting portion between the quartz tube 82 and the processing chamber 91 described later.

Referring again to FIG. 11, the structure of the plasma processing section B of the plasma device 81 according to the fourth embodiment will be described. The plasma processing unit B includes a processing chamber 91 for processing an object to be processed, for example, a wafer W by the plasma flow generated by the plasma generation unit A, and the wafer W is placed and fixed in the processing chamber 91. A susceptor 92 for storing is stored. The susceptor 92 is connected to a second high frequency power supply 94 via a matching box 93, and when performing an etching process according to a command from the controller 87, an RF bias can be applied to the susceptor 12. Is configured.

A second gas supply conduit 99 capable of introducing a second process gas from a second gas source 98 via a mass flow controller (not shown) into the shoulder of the processing chamber 91.
An exhaust pipe 96 communicating with an exhaust system 95 such as a vacuum pump is provided below the processing chamber 91 on the opposite side.
Is connected to the processing chamber 91 depending on the processing step.
A process gas is introduced into the inside of the chamber, or the processing chamber 9
The inside of 1 can be evacuated.

Further, according to this embodiment, the processing chamber 91
The magnetic field forming means 97 is arranged so as to surround the side wall of the. As shown in detail in FIG. 14, the magnetic field forming means 97 is configured by arranging a plurality of permanent magnets 97a, 97b and the like in an annular shape so that the polarities are alternately different, and the magnetic field lines as shown by arrows in FIG. A multipole magnetic field having Due to the action of this multipolar magnetic field, it becomes possible to shape and hold the plasma flow introduced from the plasma generating section A near the processing surface of the wafer W which is the object to be processed, as will be described later.

The plasma device 81 according to the fourth embodiment is configured as described above. Next, its operation will be described. When performing etching processing, a load lock (not shown) is carried out from a cassette chamber (not shown) by a transfer arm. The wafer W, which is an object to be processed, transferred to the processing chamber 9 from the load lock chamber through a gate valve (not shown).
1 is transported to the inside. That is, a reduced pressure atmosphere is previously set, for example, 10 ⁻⁶
It is conveyed into the processing chamber 91 set to Pa, and placed and fixed on the susceptor 92 in the processing chamber 91 by a fixing means such as an electrostatic chuck (not shown).

Next, the wafer W is supplied from the first gas supply line 90 at the top of the dome of the quartz tube 82 and the second gas supply line 99 provided at the shoulder of the processing chamber 91.
A predetermined process gas for plasma etching is introduced into the quartz tube 82 and the processing chamber 91.
At this time, the pressure in the processing chamber 91 is adjusted to, for example, 10 ⁻³ Torr. For example, the first gas supply line 90
It is possible to introduce an inert gas such as argon from the above and supply Cl ₂ or CHF ₃ from the second gas supply conduit 99. As described above, the process gas can be supplied to the plasma generating unit A and the plasma processing unit B from the two series of gas supply pipes, so that the optimum mixing ratio of the process gas for the etching can be set. By separately setting parameters in the plasma processing unit B and the plasma processing unit B, respectively, plasma etching processing with more excellent controllability can be performed.

When plasma is generated, an appropriate high-frequency current is sent from the first high-frequency power source 86 to the antenna means 83 to form an alternating electric field in the processing chamber 91, and the power source 88 drives the electromagnetic coil 84. By exciting, a static magnetic field having magnetic lines of force is formed downward in the vertical direction, that is, in the axial direction of the quartz tube 82. And EC to be described later
When the R condition is satisfied, the electrons existing in the ECR region make a spiral motion so as to wind around the magnetic field lines of the magnetic field, reach the plasma potential, and are accelerated in the weak magnetic field direction, that is, in the vertical direction downward. As a result, it becomes possible to form a plasma flow in a direction perpendicular to the processing surface of the wafer W which is the object to be processed.

Here, electron cyclotron resonance (EC
The condition R) is obtained by satisfying B = 2πm _e f _c / e. However, in the above formula,
B is the magnetic flux density, m _e is the mass of the electron, f _c is the frequency, and e is the charge. Therefore, in the conventional microwave ECR plasma device, the industrially available 2.45 GHz
8 as a magnetic field that satisfies the ECR condition for the microwave
Since 75 Gauss was required, a large heavy magnet was required to obtain the magnetic field, and the device had to be increased in size. Also, a special waveguide for propagating microwaves was required.

However, it is possible to achieve the ECR condition with a lower magnetic field by using a lower frequency.
It is clear from the above equation. Therefore, according to the plasma device 81 according to the present embodiment, the antenna means 83 has, for example, 10
Since an alternating electric field can be formed by supplying a high frequency current of 0 MHz or less, for example, 35 Gaus
By forming a very small magnetic field of about s, it is possible to satisfy the ECR condition. Therefore, it is sufficient to use a much smaller electromagnetic coil than the conventional device, and the device can be simplified and downsized.

As shown in FIG. 13, the lines of magnetic force generated by the first magnetic field forming means form a divergent magnetic field which is bent outward in the processing chamber as it goes downward in the vertical direction. Therefore, the plasma flow toward the target object W also tends to diverge. Particularly, in the conventional microwave ECR plasma device,
Since a large magnetic field of 75 Gauss must be used, the divergent magnetic field formed in the processing chamber 91 also becomes large, and the divergence tendency of the plasma flow also becomes large.
It was difficult to vertically inject the plasma stream onto the treated surface of the above.

However, according to the plasma device 81 according to the present embodiment, a small magnetic field of 35 Gauss can be used, so that the divergent magnetic field generated in the processing chamber 91 can also be made small and the inside of the processing chamber 91 can be reduced. It is possible to minimize the divergence tendency of the introduced plasma stream. In particular, at a point about 20 to 30 cm away from the ECR region, the influence of the divergent magnetic field can be almost ignored, so that the plasma flow can be vertically guided to the processing surface of the wafer W, and thus the selection ratio is high. Good anisotropic etching can be achieved.

Further, since the multi-pole magnetic field forming means 97 as shown in FIG. 14 is arranged around the processing chamber 91 of the plasma apparatus 1 shown in FIG. It is possible to shape and hold the plasma flow introduced into the device so as to correspond to the processed surface of the object W to be processed. Further, by reducing the divergence tendency of the plasma flow described above by the magnetic field forming means 97 having such a multi-pole structure and making the plasma flow vertically incident on the processing surface, it is possible to secure a high selection ratio and uniform etching. Become.

In the embodiment shown in FIG. 11, the susceptor 9 is used.
An RF bias can be applied from the second high frequency power supply 94 to the second via the matching box 93. Therefore, by appropriately applying an RF bias according to the processing gas or gas pressure used,
It is possible to accelerate the ions in the plasma flow and to make the ion flow uniform.

The wafer W which is the object to be processed as described above
When the processing of step 1 is completed, the exhaust pipe line 96 is opened, the residual processing gas and the reactive organisms in the processing chamber 11 are sufficiently exhausted by the exhaust system 95 such as a vacuum pump, and then the side surface of the processing chamber 91 is removed. A gate valve (not shown) provided is opened, and the object to be processed on the susceptor is carried out to the load lock chamber by the transfer arm. The above is the description of the operation when the plasma device 1 according to the fourth embodiment is used.

Next, another embodiment relating to the introduction path of the process gas from the first gas supply conduit 90 of the top dome portion of the quartz tube 82 will be described with reference to FIGS.
Will be described with reference to. In the fourth embodiment of FIG. 11, the processing gas is directly introduced into the quartz tube 82 from the first gas supply line 90 formed in the top dome portion of the quartz tube 82. In order to disperse uniformly and rapidly in the chamber 91, the configuration shown in FIG. 15 or 16 can be adopted. In another embodiment shown in FIG. 15, the processing gas is introduced through a plate member 101 having a plurality of through holes 100 formed therein, to homogenize and accelerate the gas dispersion.

In another example shown in FIG. 16, a sponge-like porous material 102 is installed in the vicinity of the first gas supply pipeline 90, and the processing gas is a minute gas in the porous material 102. The gas is introduced into the plasma generating part A through the holes 103, and the gas dispersion can be made uniform and accelerated.

Next, referring to FIGS. 17 and 18, the fifth
Examples will be described. However, regarding the constituent members having the same function and structure as the first embodiment shown in FIG.
By giving the same numbers, duplicate explanations are omitted. In the fifth embodiment, the quartz tube 8 shown in FIG.
Instead of 2, the quartz plate 110 is arranged on the upper surface of the processing chamber 91, and the antenna means 111 is installed on the outer surface of the quartz plate 110.

As shown in FIG. 18, this antenna means 111 is a spiral antenna having a spiral shape, and it is possible to efficiently form an alternating electric field by applying a high frequency current from a high frequency power source 86 via a matching box 85. Is possible. The antenna structure provided on the outer surface of the quartz plate 110 is not limited to the above shape as long as it can form a desired alternating electric field in a desired region.

For example, various types of antennas shown in FIGS. 4 to 10 can be used, and in such a case, the antenna shown in FIG.
It is possible to adopt the connection configuration of the high frequency power supply and the capacitor shown in FIG. Moreover, by configuring the connection of the antenna and the high frequency power source in such a manner, as described in the corresponding part, it becomes possible to make the plasma density uniform and perform more uniform plasma treatment. .

Also in this fifth embodiment, as shown in FIG.
Similar to the embodiment shown in FIG. 7, an electromagnetic coil 84 is installed above the antenna means 111, and is configured to be able to form a static magnetic field having magnetic force lines that gradually diverge downward in the vertical direction. There is. Thus, also in this embodiment, by appropriately adjusting the outputs of the antenna means 111 and the electromagnetic coil 84, a desired area,
For example, it is possible to form the ECR region in a region of 20 to 30 cm above the treated surface of the object to be treated.

Furthermore, according to the present embodiment, it is not necessary to use a bulky constituent member such as the quartz tube 82 in the plasma device 81 according to the first embodiment shown in FIG. It is possible to reduce the size.

Next, a sixth embodiment will be described with reference to the accompanying drawings. This embodiment is an example applied to a plasma etching apparatus. As shown in FIG. 19, a plasma etching apparatus 121 according to the sixth embodiment is shown. Is provided with a processing chamber 122 made of, for example, aluminum that is airtight. A susceptor 123 is arranged substantially in the center of the processing chamber 122, and an object to be processed is placed on the susceptor 123.
For example, the wafer W is placed and fixed.

A processing gas supply conduit 124 is attached to the shoulder of the processing chamber 122, and Cl ₂ and C are supplied from a gas source 125 via a mass flow controller (not shown).
A reactive gas such as HF ₃ can be supplied into the processing chamber 122. Further, an exhaust pipe 126 is attached to the lower side of the processing chamber 122 opposite to the side where the processing gas supply pipe 124 is attached, and an exhaust system 127 such as a vacuum pump is used to evacuate the vacuum if necessary. It is constructed so that it can be pulled.

Further, as shown in FIG. 19, on the upper surface of the susceptor 123 on which the wafer W to be processed is placed, the focus ring 1 made of quartz and surrounding the wafer W is formed.
30 is provided so as to be higher than the surface to be processed of the wafer W. The focus ring 130 has the effect of concentrating the plasma generated on the susceptor 123 on the surface to be processed and increasing the rate of processing, such as etching. Further, the focus ring 130 causes the susceptor 12 made of aluminum by the plasma.
The exposed part that is not covered by the object to be processed of 3 is etched,
It also has the effect of preventing the generation of dust.

Further, an electrostatic chuck 132 is provided on the surface of the susceptor 123 holding the object to be processed. The electrostatic chuck 132 is formed by bonding a conductor 131 such as a copper foil to an insulating film, for example, polyimide resin with polyimide, and does not peel off the film from the susceptor 123 even at a high temperature, for example, 100 ° C. to 150 ° C. , And has a function of accurately holding the wafer W to be processed. The electrostatic chuck 132 includes a power switch 134 via an electric wire 133.
The power switch 134 is connected to the DC power source 13
It is electrically grounded via 5. This DC power supply 135
When a higher voltage, for example, 2 KV, is applied to the conductor 131 of the electrostatic chuck 132, the wafer W that is the target object is processed.
Is configured to be adsorbed and held.

Inside the susceptor 123, a temperature adjusting means for the object to be treated, for example, liquid nitrogen is supplied from a supply means (not shown) via a pipe 136, and a tank capable of temporarily storing the liquid nitrogen. 137. By this temperature adjusting means, the object to be plasma-processed is cooled, for example, on the susceptor 123 and is maintained at a temperature suitable for the processing, for example, a predetermined temperature of 0 ° C. to −150 ° C. during the processing. It is possible to provide an apparatus suitable for processing that depends on the temperature of the processing body, such as etching, ashing, and film formation. Especially in the etching of semiconductor wafers,
0.3μ by forming contact holes of 64M memory or more
Etching of m or less requires fine processing. For the technique of protecting the sidewall of the contact hole with a reaction product of the processing gas and etching the bottom surface, the semiconductor wafer is cooled to a low temperature, for example, -100 ° C or less. Need to be processed.

The supply port 139 of the gas supply line 124 to the processing chamber 122 is diverted via a gas diffusion plate (not shown), and the supply port of the processing chamber 122 has a porous gas diffusion showerhead. For example, glassy carbon obtained by carbonizing a fluorocarbon resin or a phenol resin is provided. The gas supply port made of this glassy carbon can supply a uniform processing gas to the object to be processed placed on the susceptor 123, and the processing result, for example, a high uniformity in the processing surface of the etching processing can be obtained. It is configured to be able to.

As is apparent from FIG. 20, the center of the top wall surface of the processing chamber 122 is cut out in a substantially circular shape, and the disk-shaped insulating member 128 is hermetically attached thereto. The material of the insulating member 128 is not particularly limited as long as it is an insulating member such as quartz glass or ceramic material, but when transparent quartz glass is used,
It is possible to visually check the light emission state of the plasma in the processing chamber 2.

A loop antenna 129 and a magnetic pole member 140 are mounted and fixed on the upper surface of the insulating member 128, that is, on the outer side of the processing chamber 122. The loop antenna 12
Although 9 can be made of a conductive material such as a copper wire or a copper tube, it is preferable to use a copper tube having excellent cooling characteristics. Further, in this embodiment, as apparent from FIG. 20, the loop antenna 12 that draws a loop of one turn is shown.
9 is used, but it is not limited to the illustrated example as long as a rotating electric field can be formed in the processing chamber by applying a high frequency current.

For example, various types of antennas shown in FIGS. 4 and 8 can be used, and in such a case, as shown in FIG.
The connection configuration of the high frequency power supply and the capacitor shown in FIG. 8 can be adopted. Moreover, by configuring the connection of the antenna and the high frequency power source in such a manner, as described in the corresponding part, it becomes possible to make the plasma density uniform and perform more uniform plasma treatment. .

The loop antenna 129 has the first high frequency power source 142 via the matching box 141.
Is configured so that a high frequency current can be applied. Then, according to a command from the controller 143,
For example, by applying a high frequency current of 13.56 MHz to the loop antenna 129, the insulating member 128
It is possible to satisfy the plasma generation condition by forming a rotating electric field in the processing chamber 122, accelerating the electrons, through.

As the magnetic pole member 140 provided on the insulating member 128, it is preferable to use nickel-zinc based soft ferrite having low conductivity. When a magnetic pole material having high conductivity is used, an eddy current is generated due to an alternating magnetic field generated when a high frequency current is applied, and there is a possibility that a desired magnetic field cannot be formed in the processing chamber 2.

Regarding the shape of the magnetic pole member 140,
In the case of the illustrated embodiment, the circumference is made thicker and thinner at the center to make the density distribution of the plasma in the processing chamber 122 uniform within the surface. As will be described later, the shape of the magnetic pole member 140 will be described. Can be appropriately determined according to the processing conditions.

Further, the horizontal cross-sectional area of the magnetic pole member 140,
That is, the cross-sectional area of the wafer W as the object to be processed in the processing chamber 122 taken along a plane substantially horizontal to the processing surface is larger than the area of the processing surface of the wafer W. . With this configuration, the magnetic field generated by the magnetic pole material 140 can be applied to the entire processing surface of the wafer W, which is the object to be processed, and the density distribution of plasma can be controlled more precisely.

When a high frequency current is applied to the loop antenna 129 to generate plasma, a demagnetizing field is generated in the magnetic pole member 140, which may adversely affect the magnetic field generated by the magnetic pole member 140. Therefore, according to the present invention, the above problems are overcome by providing the magnetic pole member 140 with a thickness that allows the influence of the demagnetizing field to be ignored, or by devising a longer magnetic path.

A second high frequency power source 145 is connected to the susceptor 123 via a matching box 144, and a high frequency bias potential is applied to the susceptor 12 during an etching process according to a command from the controller 143.
It is configured so that it can be applied to No. 3. The susceptor 123 is connected to the insulator 138 from the processing chamber 122.
It is configured to be insulated by.

Further, according to this embodiment, the processing chamber 12
Magnetic field forming means, for example, permanent magnets 146a and 146b are arranged so as to surround the side wall of the second magnet. As shown in detail in FIG. 21, the magnetic field forming means 146 is formed by arranging a plurality of permanent magnets 146a, 146b and the like in an annular shape so that the polarities are alternately different, and the magnetic field lines shown by the arrows in FIG. To form a multipole magnetic field. Due to the action of the multi-pole magnetic field, the plasma flow that is about to collide with the inner wall of the processing chamber 122 is pushed back to the center of the processing chamber 122, and the plasma is shaped and held near the processing surface of the wafer W that is the object to be processed. Is configured to be possible.

The plasma etching apparatus 121 according to the sixth embodiment is constructed as described above. Next, its operation will be explained.
A wafer W, which is an object to be processed, is transferred from an unillustrated cassette chamber to an unillustrated load lock chamber by an appropriate transfer means, for example, a transfer arm, and a gate valve 147 provided on the side surface of the process chamber 122 from the load lock chamber. (Refer to FIG. 20) to be transferred into the processing chamber 122. Further, the wafer W is preliminarily reduced in pressure, for example, 10 ⁻⁶ Tor.
The susceptor 1 is conveyed to the processing chamber 122 whose pressure is reduced to r.
It is attracted and held by the electrostatic chuck 132 on 23.

Then, from the gas supply conduit 124 provided at the shoulder of the processing chamber 122, the wafer W to be processed is processed.
A predetermined process gas, for example, Cl ₂ or CHF ₃ for plasma etching is introduced into the processing chamber 122. At this time, the pressure in the processing chamber 122 is, for example, 10
-Adjusted to ^-3 Torr.

When performing plasma etching,
From the first high frequency power supply 142 to the matching box 141
A high frequency current of, for example, 13.56 MHz is applied to the loop antenna 129 via the. A magnetic field that vertically moves up and down inside the processing chamber 122 is formed by the high frequency current, and a rotating electric field is formed around the magnetic field. Electrons are accelerated to the plasma potential by this rotating electric field, and plasma is formed in the processing chamber 122. In this case, according to the present embodiment, it is possible to form a very uniform rotating electric field by the loop antenna 129, and therefore it is possible to form a plasma having high uniformity in the processing chamber 122.

Further, since the magnetic field forming means 146 constituted by a plurality of permanent magnets 146a and 146b as shown in FIG. 3 is arranged around the processing chamber 122 of the plasma etching apparatus 121 shown in FIG. The plasma flow that is about to collide with the inner wall of the processing chamber 122 can be pushed back to the center of the processing chamber 122, and the plasma can be shaped and held in the vicinity of the processing surface of the wafer W that is the object to be processed. Therefore, a uniform etching process can be performed on the processed surface of the wafer W that is the object to be processed.

Further, according to the plasma device 121 of the present embodiment, the second high frequency power source 145 is connected to the susceptor 123. Since the second high frequency power supply 145 can be controlled independently of the first high frequency power supply 142 for generating plasma, a high frequency bias potential between the generated plasma and the susceptor 123 or the wafer W is generated. Can be adjusted freely. Therefore, by appropriately applying a high frequency bias according to the processing gas and the gas pressure used, it is possible to accelerate the ions in the plasma flow and to make the ion flow uniform.

When the processing of the wafer W in the processing chamber 122 is completed as described above, the exhaust pipe 126 is opened, and the processing chamber 1 is opened by the exhaust system 127 such as a vacuum pump.
After the residual processing gas and reaction products in 22 are sufficiently exhausted, the gate valve 147 provided on the side surface of the processing chamber 122 is opened, and the wafer W on the susceptor 123 is opened by a transfer arm (not shown). The process ends by carrying out the load lock chamber (not shown).

Next, referring to FIG. 22 and FIG.
The structure and action of the soft ferrite which is the magnetic pole material constructed based on this embodiment will be described. Generally, the density distribution of plasma in the processing chamber 122 is affected by the magnetic field distribution in the processing chamber 122. Therefore, according to the present embodiment, the magnetic pole material 1 such as soft ferrite is formed on the upper surface of the insulating member 128 to adjust the magnetic field distribution in the processing chamber 122.
By arranging 40 and changing its shape, the magnetic field distribution in the processing chamber 122 can be adjusted and the plasma density distribution can be adjusted freely.

However, according to the present embodiment, in order to control the plasma density distribution over the entire processing surface of the wafer W, the horizontal cross-sectional area of the magnetic pole member 140, that is, the processing surface of the wafer W, is substantially formed. It is important to configure so that the area of the cross section cut by parallel planes is larger than the area of the processing surface. Further, as described above, when a high-frequency current is applied to the loop antenna 129, a demagnetizing field is generated in the magnetic pole material 10, so it is important to give the magnetic pole material 0 a thickness such that its influence can be ignored.

After satisfying the above conditions, the magnetic pole material 14
The density distribution of plasma in the processing chamber 122 can be freely adjusted by appropriately adjusting the shape of the soft ferrite constituting the zero component. For example, in the example shown in FIG. 19, assuming that the density distribution around the plasma is lower than the center density distribution of the plasma when the magnetic pole member 140 is not installed, and it is desired to make the plasma uniform,
As shown in the figure, in the vertical cross section of the magnetic pole member 140, the peripheral portion is made thicker than the central portion, or the magnetic path is made longer so that the plasma can be made uniform.

The required plasma density distribution varies depending on factors such as the type of the object to be processed, the reactive gas and the gas pressure. Therefore, according to the present invention, the shape of the magnetic pole member 140 is appropriately adjusted. This makes it possible to obtain a desired optimum plasma density distribution.

For example, in the example shown in FIG. 22, by completely covering the periphery of the loop antenna 129 'with the magnetic pole material 140', the influence of the demagnetizing field generated by applying the high frequency current to the loop antenna 129 'is canceled. It is possible to reinforce the magnetic field over the entire processing surface of the wafer W that is the object to be processed.

Further, in the example shown in FIG. 23, the magnetic pole material 140 ″ of soft ferrite is formed around the loop antenna 129 ″.
The effect of the demagnetizing field is offset by covering with, and the central portion of the magnetic pole member 140 ″ is made thinner than the surroundings, thereby promoting in-plane homogenization of plasma in the processing chamber 122. it can.

Finally, in the example of FIG. 19, the loop antenna 1
Although the structure of 29 is shown as a simple structure having a one-turn loop, the structure of the loop antenna 129 is configured to generate a good rotating magnetic field by applying a high frequency current.
As long as it can be formed inside, it is not limited to the above example. For example, as shown in FIG. 24, it is also possible to arrange loops of one turn so as to overlap each other to form a loop antenna 149 in which the rotating magnetic field is strengthened. Besides, it is also possible to use a spiral loop antenna composed of a loop of several turns to form a rotating magnetic field over a wide range.

In the above-mentioned embodiment, the supply of the processing gas is performed, for example, on the upper surface of the chamber or the processing chamber as shown in FIGS.
6, the shower head 150 shown in FIG. 27 is provided,
It may be configured to supply from the shower head 150. The shower head 150 is made of, for example, an insulating material such as fused silica, quartz, or ceramics, and has a gas inlet 151 and a buffer chamber 152 therein.
It has a large number of ejection holes 153 on the back surface. Then, the processing gas supply pipe 154 is connected to the gas inlet 151.

When the shower head 150 having such a structure is used, the processing gas introduced into the buffer chamber 152 from the gas introduction port 151 is once blocked and then discharged from each discharge hole 153 at a uniform pressure and flow rate. It is discharged or jetted into the processing chamber. Therefore, this shower head 5
By using 0, the processing gas is uniformly supplied into the processing chamber and the chamber, so that the plasma density can be made more uniform.

The plasma device according to the present invention has been described above based on the embodiments. However, the plasma device according to the present invention is not limited to the above embodiments, and an ashing device,
It can also be applied to a sputtering apparatus, an ion implantation apparatus, a plasma CVD apparatus and the like. Further, the object to be processed can also be applied to various plasma devices for processing an LCD substrate, for example. In this case, the guide member of the guide unit and the antenna unit may be configured according to the planar form of the substrate. For example, when the LCD substrate has a rectangular shape, the loop-shaped guiding member and the antenna means may be formed of a linear or tubular conductive material in a so-called rectangular loop shape. Further, as for the spiral shape, it may be formed into a so-called rectangular spiral shape by sequentially bending inward at a right angle. With this configuration, the same effect as each of the above-described embodiments can be obtained even for the rectangular object to be processed, and it is possible to perform uniform plasma processing.

[0137]

According to the first aspect of the present invention, it is possible to displace the generation region of the generated plasma, and it is possible to make the plasma uniform by changing the distribution of the plasma density. . According to the second and third aspects, since the plasma originally generated is relatively uniform, it is possible to perform the plasma treatment with more excellent uniformity on the object to be treated.

Further, according to the fourth, fifth and sixth aspects, it is possible to control the plasma density in a wider range, and it is possible to perform the plasma processing with more excellent uniformity on the object to be processed. Further, as described in claim 7, when a plurality of induction members are provided and the high frequency power supplied to each induction member is independently controlled, an alternating pattern induced by each induction member is provided. Since the strength of the electric field can be adjusted,
Extremely fine and wide range plasma density control is possible.

When the paramagnetic member is plate-shaped as described in claim 8, it is easy to adopt as a device structure in terms of space. Further, in claim 9, the shift of the plasma region can be made large, and from this point, it is possible to control the distribution of the plasma density over a wide range.

According to the tenth aspect, the number of magnetic fluxes vertically penetrating the central portion is reduced, the magnetic field strength of the induced alternating electric field is reduced, and the plasma generation region is reduced even if the permanent metal member is not used. Since it is displaced outward in the radial direction, this can be utilized to make the plasma density uniform.

According to the eleventh aspect, it is possible to make the induced alternating electric field relatively dense in the outer portion and the central portion, and by utilizing this, the plasma density is made uniform. Is possible.

According to the twelfth aspect, it is possible to further accelerate the ions in the plasma, and for example, in the etching process, the etching rate can be improved.

On the other hand, according to the thirteenth aspect, even if the magnetic flux density of the static magnetic field formed in the direction orthogonal to the alternating electric field by the antenna means is reduced, it becomes possible to achieve the ECR condition, and therefore the first condition therefor. The magnetic field forming means can be miniaturized. Also, a small magnetic field is sufficient to achieve the ECR condition, so the influence of the divergent magnetic field on the plasma flow can be minimized. Since the second magnetic field forming means is provided so as to surround the processing chamber, the expansion region of the plasma flow introduced into the processing chamber is expanded to a planar shape in the vicinity of the object to be processed, and a uniform plasma is generated in the processing region. It is possible to maintain the flow and to direct the direction of the plasma flow perpendicular to the processing surface of the object to be processed.

According to the fourteenth aspect, the plasma state can be controlled by the number of turns of the antenna means.
Therefore, for example, a uniform alternating electric field can be formed substantially in the center of the plasma generating chamber, and the plasma generating portion and the plasma processing portion can be separated from each other. It becomes possible to set and control the parameters of, and it is possible to carry out the plasma processing with higher accuracy.

According to the fifteenth aspect, further simplification and miniaturization of the device can be achieved.

According to the sixteenth, seventeenth and eighteenth aspects, the plasma density can be controlled in a wider range, and the uniformity of the plasma can be further improved. In this respect, according to claim 19, it is possible to control the plasma density more finely and in a wider range.

According to the twentieth aspect, it becomes possible to further simplify and downsize the entire apparatus. Therefore, claim 13
According to 20 to 20, the ECR condition can be achieved by using a much smaller high-frequency current as compared with the conventional microwave ECR plasma device, so that the magnet for forming the necessary magnetic field can be miniaturized. This is possible, the maintenance is easy, and the plasma device itself can be downsized and simplified. In addition, compared to the conventional equipment, a smaller magnetic field is used, so it is possible to minimize the influence of the divergent magnetic field generated in the processing chamber on the plasma flow, and the plasma flow is more perpendicular to the processed surface of the object to be processed. Can be incident on.

According to the twenty-first aspect, a rotating electric field is formed in the processing chamber by applying a high-frequency current from the first high-frequency power source to the induction electric field forming means, and the rotating electric field accelerates electrons to satisfy the plasma generation condition. To be achieved. As described above, according to the twenty-first aspect, it is possible to generate the plasma without using the electrode, and thus it is possible to reduce heavy metal contamination of the product due to the electrode material.

When the induction electric field forming means is constituted as a loop antenna as in claim 22, a more uniform rotating electric field can be formed, so that plasma excellent in in-plane uniformity can be generated in the processing chamber. Can be generated.

According to the twenty-third aspect, since it is composed of two or more antenna members, it is possible to adjust the plasma density in a wider range, and to generate a plasma having excellent in-plane uniformity in the processing chamber. be able to. When the high frequency current applied to each antenna member is independently controlled as in the twenty-fourth aspect, it is possible to control the plasma density more finely and in a wide range.

According to the twenty-fifth aspect, since soft ferrite is used for the magnetic pole material, the magnetic field in the processing chamber is adjusted as in the twenty-sixth aspect to freely adjust the density distribution of the generated plasma in the processing chamber. It is easy to do. Further, by forming the cross-sectional area of the magnetic pole material cut at a plane substantially parallel to the processing surface of the object to be processed to be wider than the processing surface of the object to be processed, over the entire processing surface of the object to be processed,
It is possible to irradiate a plasma stream having a desired density distribution.

Therefore, according to the twenty-first to twenty-sixth aspects, since the electrodeless discharge can be performed by using the loop antenna, the high frequency power for plasma generation and the high frequency bias potential can be adjusted independently. Moreover, it is possible to avoid heavy metal contamination due to the electrode material.
Moreover, by simply changing the shape of the soft ferrite, the density distribution of the plasma in the processing chamber can be easily adjusted, and a high in-plane uniformity of the plasma flow can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a first embodiment.

FIG. 2 is an explanatory view schematically showing a cross section showing the configuration of the first embodiment.

FIG. 3 is an explanatory diagram showing an operation of the first embodiment.

FIG. 4 is an explanatory plan view showing a loop antenna which is another example of the antenna used in the first embodiment.

FIG. 5 is an explanatory plan view showing a spiral antenna which is another example of the antenna used in the first embodiment.

FIG. 6 is an explanatory plan view of an antenna used in the second embodiment.

FIG. 7 is a plan view showing another antenna used in the second embodiment.

FIG. 8 is an explanatory plan view of the antenna used in the third embodiment.

FIG. 9 is a plan view showing another example of the antenna that can be used in the third embodiment.

FIG. 10 is a plan view showing another example of the antenna that can be used in the third embodiment.

FIG. 11 is a schematic vertical sectional view of a plasma device according to a fourth embodiment.

FIG. 12 is a schematic sketch of a plasma generating portion of the plasma device shown in FIG.

FIG. 13 is a schematic cross-sectional view in which a plasma generating portion of the plasma device shown in FIG. 11 is horizontally cut.

FIG. 14 is a schematic cross-sectional view of a plasma-processed portion of the plasma device shown in FIG. 11, which is cut horizontally.

FIG. 15 is a schematic cross-sectional view showing another example of the gas introduction path to the plasma generating portion that can be used in the fourth embodiment.

FIG. 16 is a schematic cross-sectional view showing another example of the gas introduction path to the plasma generating portion that can be used in the fourth embodiment.

FIG. 17 is a schematic vertical sectional view of a plasma device according to a fifth embodiment.

FIG. 18 is a schematic plan view of the plasma device shown in FIG.

FIG. 19 is a schematic vertical sectional view of a plasma etching apparatus according to a sixth embodiment.

20 is a plan view of the plasma etching apparatus shown in FIG.

21 is a horizontal cross-sectional explanatory view of a processing chamber portion of the plasma etching apparatus shown in FIG.

FIG. 22 is a cross-sectional view of essential parts of another example of the relationship between the loop antenna and the soft ferrite of the plasma etching apparatus according to the sixth embodiment.

FIG. 23 is a cross-sectional view of main parts of another example of the relationship between the loop antenna and the soft ferrite of the plasma etching apparatus according to the sixth embodiment.

FIG. 24 is a cross-sectional view of main parts of another example of the relationship between the loop antenna and the soft ferrite of the plasma etching apparatus according to the sixth embodiment.

FIG. 25 is a perspective view showing an overview of a shower head that can be used in each embodiment of the present invention.

FIG. 26 is a bottom view of a shower head that can be used in each example of the present invention.

FIG. 27 is a vertical cross-sectional view of a shower head that can be used in each example of the present invention.

[Explanation of symbols]

 1 plasma device 2 chamber 3 upper wall 4 mounting table 6 high frequency power supply 15 gas supply source 18 exhaust system 20 antenna 21 high frequency power supply 24 thin plate W wafer

Claims (26)

[Claims] 1. A processing chamber configured to perform plasma processing on an object to be processed on a susceptor, and a portion provided outside the processing chamber and corresponding to the object to be processed via an insulator, and A guiding means for forming an induction electric field in the vicinity of the object to be processed by supplying high-frequency power; and a paramagnetic member arranged so that at least a part thereof overlaps the guiding means. Plasma equipment. 2. The plasma device according to claim 1, wherein the guide member forming the guide means has a single spiral shape. 3. The plasma device according to claim 1, wherein the guiding member forming the guiding means has a single loop shape. 4. The guiding means comprises two or more guiding members, each guiding member has a single spiral shape, and each guiding member is concentrically arranged.
The plasma device according to claim 1. 5. The guiding means comprises two or more guiding members, each guiding member has a single loop shape, and each guiding member is concentrically arranged. 1. The plasma device according to 1. 6. The guide means comprises two or more guide members, each guide member has a single spiral shape and a single loop shape, and the guide members are arranged concentrically. The plasma device according to claim 1. 7. The plasma device according to claim 4, wherein the high frequency power supplied to the induction member is controlled independently of each other. 8. The paramagnetic member has a plate shape, and the paramagnetic member has a plate shape.
The plasma device according to. 9. The paramagnetic member is made of copper, and the paramagnetic member is made of copper.
Or the plasma apparatus according to 8. 10. A processing chamber configured to perform plasma processing on an object to be processed on a susceptor, and a portion provided outside the processing chamber and corresponding to the object to be processed via an insulator, and And a guide means for forming an induction electric field in the vicinity of the object to be processed by the supply of high-frequency power, wherein the guide means is constituted by a spiral guide member having a space region in a central portion thereof. And a plasma device. 11. The plasma device according to claim 11, wherein the guiding means is composed of a spiral guiding member having a pitch different between the outer portion and the central portion. 12. A high frequency applying means for applying a high frequency bias to the object to be processed, further comprising: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11.
The plasma device according to. 13. A plasma generating unit and a plasma processing unit, wherein the plasma flow generated by the plasma generating unit is introduced into the processing chamber of the plasma processing unit so as to be mounted on the susceptor in the processing chamber. A plasma device for performing plasma processing on a fixed object to be processed, wherein an antenna for forming an alternating electric field in the processing chamber through an insulating member by applying a high-frequency current to the plasma generator. Means and a first magnetic field forming means arranged so as to surround the plasma generating portion to form a static magnetic field in a direction orthogonal to the alternating electric field, and appropriately adjusting the alternating electric field and the static magnetic field. An electron cyclotron resonance region is formed in the processing chamber, and the plasma processing unit is disposed so as to surround the processing chamber and is introduced into the processing chamber. Wherein the second magnetic field forming means for shaping held is provided the plasma stream that is relative to the workpiece, the plasma device. 14. The insulating member forms a plasma generating chamber communicating with the processing chamber, and the antenna means is arranged so as to make at least one turn around an outer peripheral portion of the plasma generating chamber. The plasma device according to claim 13. 15. A single spiral antenna in which the insulating member constitutes at least a part of a wall portion of the processing chamber, and the antenna means is arranged substantially parallel to a surface of an outer wall portion of the insulating member. 14. The plasma device according to claim 13, wherein: 16. The insulating member constitutes at least a part of a wall portion of the processing chamber, and the antenna means is composed of two or more antenna members arranged substantially parallel to a surface of an outer wall portion of the insulating member. 14. The plasma device according to claim 13, wherein each antenna member is a spiral antenna, and the antenna members are concentrically arranged. 17. The insulating member constitutes at least a part of a wall portion of the processing chamber, and the antenna means is composed of two or more antenna members arranged substantially parallel to the outer wall surface of the insulating member. 14. The plasma device according to claim 13, wherein each antenna member is a loop-shaped antenna, and these are arranged concentrically. 18. The insulating member constitutes at least a part of a wall portion of the processing chamber, and the antenna means is constituted by two or more antenna members arranged substantially parallel to a surface of an outer wall portion of the insulating member. 14. The plasma device according to claim 13, wherein each antenna member is a spiral antenna and a loop antenna, and these are arranged concentrically. 19. The plasma device according to claim 16, 17 or 18, wherein the high frequency current applied to each antenna member is controlled independently. 20. An ECR condition is achieved by causing a high frequency current having a frequency of 100 MHz or less to flow through the antenna means and forming a magnetic field having a magnetic flux density corresponding to the frequency by the first magnetic field forming means. The plasma device according to claim 13, 14, 15, 16, 17, 18, or 19. 21. A processing chamber hermetically configured to perform plasma processing on an object to be processed mounted and fixed on a susceptor, wherein at least a part of a wall of the processing chamber is composed of an insulating member. An induction electric field forming means capable of forming a rotating electric field in a desired region in the processing chamber by applying a high frequency current from a first high frequency power source is arranged on an outer surface portion of the insulating member, and outside the processing chamber. A magnetic pole material is arranged in the vicinity of the induction electric field forming means, and the cross-sectional area of the magnetic pole material cut along a plane substantially parallel to the processing surface of the object to be processed is wider than at least the area of the processing surface. In addition, the thickness of the magnetic pole material is set to a level at which the influence of the demagnetizing field excited by the applied high-frequency current can be neglected, and the susceptor has a second adjustable power supply independent of the first high-frequency power supply. For high frequency power supply Ri wherein the are configured so as to be able to apply a bias potential, the plasma device. 22. The plasma device according to claim 21, wherein said induction electric field forming means is a loop antenna having a loop of at least one turn. 23. The induction electric field forming means is composed of two or more antenna members, each antenna member is a loop-shaped antenna, and these are arranged concentrically. The plasma device according to. 24. The plasma device according to claim 23, wherein the high frequency current applied to each antenna member is configured to be independently controlled. 25. The plasma device according to claim 21, 22, 23, or 24, wherein the magnetic pole material is soft ferrite. 26. The thickness of the magnetic pole material portion that forms a magnetic field that acts on an area where the density distribution of plasma is desired to be relatively increased is made thicker than the thickness of the magnetic pole material portion that forms a magnetic field that acts on other areas. The plasma device according to claim 21, 22, 23, 24, or 25, which is formed.