JP2015088469A - Plasma processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize, at right and left sides of an antenna, the density of plasma generated by using the antenna in a device in which an antenna having high frequency electrodes of a structure having a plurality of openings on the inner sides of two electrode conductors constituting reciprocating conductors is arranged in the direction where the main surface of the high frequency electrode and the surface of a substrate substantially become vertical to each other.SOLUTION: An antenna 28 constituting this plasma processing device has two high frequency electrodes 30 and has a structure in which the two high frequency electrodes 30 holding a cooling pipe 42 therebetween are housed in a dielectric case 40. The distance between the main surface in the outside of each high frequency electrode 30 and the external surface of the dielectric case 40 opposite to the main surface is made substantially equal to each other in the two high frequency electrodes 30.

Description

  The present invention relates to a plasma processing apparatus that uses a plasma to perform processing such as film formation by plasma CVD, etching, ashing, film formation by sputtering, and the like, and more specifically, a high-frequency current flows through an antenna. The present invention relates to an inductively coupled plasma processing apparatus that generates plasma by an induction electric field generated by the above-described method and processes a substrate using the plasma.

  An example of a plasma processing apparatus of this type, in which the antenna has a high-frequency electrode having a structure in which a plurality of openings are provided on the inner sides of two electrode conductors constituting a reciprocating conductor, It is described in Patent Document 1.

  This conventional plasma processing apparatus will be described in summary with reference to FIGS. In FIG. 1, the dielectric plate is not shown for the sake of simplicity. The illustration of the plate thickness of the high frequency electrode and the substrate is also omitted. They shall refer to FIG.

The high-frequency electrode 70 constituting the antenna 68 is arranged in parallel with two rectangular plate-like electrode conductors 71 and 72 placed close to each other with a gap 74 so as to be positioned on the same plane along the surface of the substrate 2. In addition, the electrode conductors 71 and 72 have a reciprocating conductor structure in which one end in the longitudinal direction X is connected by a conductor (not shown in the figure), and the two electrode conductors 71 and 72 have a high-frequency current I in _{which R} is flowed in opposite directions (because the high frequency, the direction of the high-frequency current I _R is inverted by the time. hereinafter the same). Frequency of the high frequency current I _R is, for example, 13.56 MHz.

  Further, notches facing each other across the gap 74 are provided on the gap 74 side of the two electrode conductors 71 and 72, and an opening 77 is formed by the facing notches, and a plurality of the openings 77 are formed. The high-frequency electrodes 70 are arranged so as to be dispersed in the longitudinal direction X.

  A dielectric plate 80 is disposed near the lower side of the high-frequency electrode 70 in order to prevent the surface of the high-frequency electrode 70 from being sputtered by charged particles (mainly ions) in the plasma 82.

The high-frequency current I _R generates a high-frequency magnetic field around the high-frequency electrode 70, thereby generating an induction electric field in the opposite direction to the high-frequency current I _R. This induction electric field accelerates electrons in a vacuum vessel (not shown) to ionize the gas in the vicinity of the antenna 68 (more specifically, near the lower side of the dielectric plate 80), thereby lowering the dielectric plate 80. Plasma 82 is generated near the side. The substrate 2 is disposed at a position facing the main surface of the high-frequency electrode 70, and the plasma 82 diffuses to the vicinity of the substrate 2, and the substrate 2 can be subjected to the above-described processing such as film formation. .

  As an effect exhibited by this plasma processing apparatus, Patent Document 1 describes the following effect.

Since the antenna 68 (more specifically, the high-frequency electrode 70) has a reciprocal conductor structure when viewed globally, the high-frequency currents I _R flow through the two electrode conductors 71 and 72 in opposite directions. The effective inductance of the antenna 68 is reduced by the mutual inductance existing between the reciprocating conductors 71 and 72. Therefore, the potential difference generated between both ends in the longitudinal direction X of the antenna 68 can be suppressed to be smaller than that of a simple flat antenna, thereby suppressing the plasma potential and reducing the plasma density distribution in the longitudinal direction X of the antenna 68. Can improve the uniformity.

When the high-frequency current I _R flowing through the high-frequency electrode 70 is viewed in detail, the high-frequency current I _R tends to flow mainly at the end portions of the two electrode conductors 71 and 72 due to the skin effect. Of these, if attention is paid to the side of the two electrode conductors 71 and 72 on the side of the gap 74, the high-frequency current I _R flows in the opposite direction to the side close to each other. In comparison, the inductance (and hence the impedance) becomes smaller. Therefore, the high-frequency current I _R will flow more along the opening 77 formed therein sides and the clearance 74 side. As a result, each opening 77 functions in the same manner as a coil dispersedly arranged in the longitudinal direction X of the antenna 68, so that a structure similar to that in which a plurality of coils are connected in series can be formed with a simple structure. it can. Therefore, with a simple structure, a strong magnetic field can be generated in the vicinity of each opening 77 to increase the plasma generation efficiency.

  By the way, when a film is formed on the substrate 2 by the conventional plasma processing apparatus shown in FIGS. 1 and 2 and the film thickness distribution thereof is measured in detail, the film thickness distribution in the longitudinal direction X of the antenna 68 has an opening 77. There was a pulsation corresponding to the arrangement, and it was found that there was still a problem in this point.

An example of the result of measuring the film thickness distribution is shown in FIG. In FIG. 3, a fluorinated silicon nitride film (SiN: F) is formed on the substrate 2 using a mixed gas of silicon tetrafluoride gas (SiF ₄ ) and nitrogen gas (N ₂ ) as a source gas. Each point on the substrate 2 located directly below the center of each opening 77 and the center between adjacent openings 77 on the central axis of the opening row in FIG. 1 (some of which are indicated by points a to f). The film thickness was measured. At this time, the pitch of the openings 77 was 48 mm, the diameter of each opening 77 was 40 mm, and the distance L ₁ between the antenna 68 and the substrate 2 was 95 mm.

  As can be seen from FIG. 3, the film thickness is small just below the center of each opening 77 (points b, d, f, etc.), and just below the center between adjacent openings 77 (points a, c, e, etc.). ), The film thickness is large, and the film thickness distribution in the longitudinal direction X of the antenna 68 pulsates corresponding to the arrangement of the openings 77. The measurement position where X in FIG. 3 is a negative value can be inferred from the above description.

Since the behavior of the high-frequency current I _R and the plasma 82 is easily affected by various objects existing in the vicinity thereof, it is not easy to clarify clearly theoretically. However, as shown in FIG. It is thought that the pulsation is caused by the following action.

(1) the high-frequency current I _R As described above, since the flows more to the periphery of the gap 74 side edges and the openings 77 of the high-frequency electrode 70 by the skin effect and low impedance due to the high frequency current I _R flowing therethrough Strong plasma generation effect. In particular, since both ends of each opening 77 (both ends in the direction perpendicular to the antenna longitudinal direction X. That is, in this example, both ends in the Y direction) 79, a reverse current does not flow nearby, so the plasma generating action is strong. In contrast, a deep plasma is generated in the lower portion 84 (see FIG. 2) of the both end portions 79, whereas the high-frequency current I _R does not flow in the center of each opening portion 77. The plasma generated at 85 is light, and this contributes to reducing the film thickness at points b, d, f, etc. on the substrate corresponding to the center. On the other hand, in the lower part between the adjacent openings 77, plasma that is lighter than the lower part 84 of the both ends 79 but darker than the lower part 85 in the center of the opening 77 is generated. Therefore, this contributes to increasing the film thickness at points a, c, e, etc. on the substrate corresponding to the center between the adjacent openings 77. In this way, the density corresponding to the arrangement of the opening 77 is generated in the plasma density in the longitudinal direction X of the antenna 68, which causes pulsation in the film thickness distribution on the substrate 2.

(2) Moreover, since the main surface and the substrate 2 of the high-frequency electrode 70 constituting the antenna 68 are opposite to each other to the parallel plate electrodes, the high-frequency electrode 70 by passing a high frequency current I _R in the high-frequency electrode 70 potential Rises, a substantially uniform (quasi-uniform) electric field is generated between the high-frequency electrode 70 and the substrate 2. That is, as in the example shown in FIG. 2, a substantially flat equipotential surface 86 is generated between the main surface of the high-frequency electrode 70 and the substrate 2. In the case of such a flat equipotential surface 86, when the plasma 82 generated near the lower side of the antenna 68 (more specifically, the dielectric plate 80) diffuses to the substrate 2 side, the plasma 82 is laterally moved. Therefore, the density of the plasma density generated in (1) is easily transferred onto the substrate 2 as it is. This also causes pulsation in the film thickness distribution on the substrate 2.

If the distance L ₁ between the antenna 68 and the substrate 2 is increased, the diffusion of the plasma 82 in the lateral direction increases until reaching the substrate 2, so that the density of the plasma density is reduced near the substrate 2. Although it is considered that the uniformity of the substrate processing can be improved, this causes another problem that the distance between the antenna 68 and the substrate 2 is increased and the plasma processing apparatus is increased in size.

  In contrast, a plasma processing apparatus capable of solving the problems of the conventional apparatus as described above has been filed separately by the same applicant as the present application (Japanese Patent Application No. 2013-173160).

  An example of the plasma processing apparatus according to this separate application will be described in summary with reference to FIGS. In FIG. 4, the dielectric case is not shown for the sake of simplicity. The illustration of the plate thickness of the high frequency electrode and the substrate is also omitted. They shall refer to FIG.

In this example, two antennas 28 are provided. Each antenna 28 has a structure in which the high-frequency electrode 30 is housed in a dielectric case 40. Since the high-frequency electrode 30 generates heat by flowing a high-frequency current I _R , a cooling pipe 42 for cooling the high-frequency electrode 30 is attached to one main surface of the high-frequency electrode 30. The dielectric case 40 can prevent the surface of the high frequency electrode 30 and the like inside thereof from being sputtered by charged particles (mainly ions) in the plasma 50.

The high-frequency electrodes 30 constituting each antenna 28 are close to each other with a gap 34 so that two electrode conductors 31 and 32 each having a rectangular plate shape that is long in the X direction form a rectangular plate shape as a whole. The electrode conductors 31 and 32 have a reciprocating conductor structure in which one ends in the longitudinal direction X of the electrode conductors 31 and 32 are connected by a conductor (not shown in the figure). High-frequency currents I _R are caused to flow in directions opposite to each other.

  In addition, each of the two electrode conductors 31 and 32 constituting each high-frequency electrode 30 is provided with a notch opposed to the side on the gap 34 side with the gap 34 interposed therebetween, and an opening 37 is formed by the opposed notch, A plurality of the openings 37 are arranged in the longitudinal direction X of the high-frequency electrode 30.

  The antenna 28 is placed in a vacuum vessel (not shown) in which the main surface of the high-frequency electrode 30 constituting each antenna 28 (ie, the larger surface of the plate-like object) and the surface of the substrate 2 are substantially the same. It is arranged in a direction perpendicular to

By flowing a high frequency current I _R in the high-frequency electrode 30 constituting each antenna 28 as described above, the high-frequency magnetic field is generated around each high-frequency electrode 30, whereby an induced electric field is generated in the high frequency current I _R and reverse To do. This induction electric field accelerates electrons in the vacuum container to ionize the gas in the vicinity of the antenna 28 and generate plasma 50 near the outside of the dielectric case 40. The plasma 50 diffuses to the vicinity of the substrate 2, and the plasma 2 can be subjected to the above-described processing such as film formation.

  Also in the plasma processing apparatus according to this another application, the high-frequency electrode 30 constituting each antenna 28 has a reciprocal conductor structure when viewed globally, and a plurality of openings 37 are formed in the longitudinal direction X in each high-frequency electrode 30. Since the structure is arranged in a dispersed manner, the same effect as the above-described effect of the conventional plasma processing apparatus described above can be obtained.

  Furthermore, according to the plasma processing apparatus according to this another application, unlike the above-described conventional apparatus, the opening of the high-frequency electrode 30 constituting the antenna 28 without having to increase the distance between the antenna 28 and the substrate 2. The density of the plasma corresponding to the arrangement 37 can be relaxed in the vicinity of the substrate 2, and the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved. This will be described in more detail with reference to the film thickness measurement result.

FIG. 6 shows an example of a result obtained by forming a film on the substrate 2 by the plasma processing apparatus and measuring the film thickness distribution in detail. In FIG. 6, a fluorinated silicon nitride film (SiN: F) is formed on the substrate 2 using a mixed gas of silicon tetrafluoride gas (SiF ₄ ) and nitrogen gas (N ₂ ) as a source gas. The film thicknesses of a plurality of points (some of which are indicated by points A to F) on the central axis 29 between the two antennas 28 arranged vertically as shown in FIG. 4 are measured. Y of each point on the substrate 2 (some of which are indicated by points a to f) located immediately below the center of the opening 37 of the high-frequency electrode 30 constituting each antenna 28 and the center between the adjacent openings 37. Intermediate points in the direction are the points A to F on the central axis 29. The measurement position where the value of X is larger than the point F in FIG. 6 and the measurement position where X is a negative value can be inferred from the above description.

At this time, the pitch of the openings 37 was 35 mm, the diameter of each opening 37 was 30 mm, the distance between the two antennas 28 was 125 mm, and the distance L ₂ between each antenna 28 and the substrate ₂ was 100 mm.

  As can be seen from FIG. 6, the film thickness in the longitudinal direction X of the antenna 28 does not have the pulsation (see FIG. 3) as seen in the case of the above-described conventional device, and the film has good uniformity. A thickness distribution is obtained. The reason why such a good result is obtained is considered to be due to the following action.

  (1) In this apparatus, the antenna 28 is arranged in such a direction that the main surface of the high-frequency electrode 30 and the surface of the substrate 2 are substantially perpendicular to each other. In the vicinity of the outside of the body case 40, both ends of each opening 37 of the high-frequency electrode 30 (both ends in the direction orthogonal to the antenna longitudinal direction X, that is, in the case of this apparatus, the antenna 28 is arranged vertically. Even if a dark plasma is generated in the side portion 64 of each of the openings 37 and a light plasma is generated in the side portion 65 at the center of each opening 37, this device is different from the conventional device, The density of the plasma is positioned in the vertical direction with respect to the substrate surface. Accordingly, while the plasma 50 is diffused toward the substrate 2, the density of the plasma is mixed and averaged to some extent, so that the density of the plasma 50 is easily relaxed in the vicinity of the substrate 2.

(2) Moreover, since the antenna 28 is its high-frequency electrode 30 main surface of the substrate 2 surface are arranged substantially to be perpendicular orientation to each other, a high frequency by flowing a high frequency current I _R in the high-frequency electrode 30 When the potential of the electrode 30 rises, the equipotential surface 66 generated between the high-frequency electrode 30 and the substrate 2 is a curved surface having a valley below the high-frequency electrode 30 except near the substrate 2 as in the example shown in FIG. It becomes a shape. Therefore, when the plasma 50 generated near the outside of the dielectric case 40 diffuses toward the substrate 2, the plasma 50 easily diffuses in the lateral direction. From this point of view, the arrangement of the openings 37 of the high-frequency electrode 30 Corresponding plasma density is easily relaxed in the vicinity of the substrate 2.

  By the actions (1) and (2) above, even if the distance between the antenna 28 and the substrate 2 is not intentionally increased, the density of plasma corresponding to the arrangement of the openings 37 of the high-frequency electrode 30 constituting the antenna 28 is changed to the substrate. 2 can be relaxed and the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved. For example, when a film is formed on the substrate 2, the uniformity of the film thickness distribution in the longitudinal direction X of the antenna 28 can be improved.

  Furthermore, since it is not necessary to darely increase the distance between the antenna 28 and the substrate 2, it is possible to prevent the vacuum vessel and thus the plasma processing apparatus from being enlarged. In addition, the time required for evacuating the vacuum vessel can be shortened. Even if the antenna 28 is arranged vertically and the antenna 28 protrudes into the vacuum vessel, the size of the vacuum vessel and thus the plasma processing apparatus can be prevented.

Japanese Patent No. 5018994 (paragraphs 0012-0014, FIG. 1 and FIG. 3)

In the plasma processing apparatus according to the another application, a cooling pipe 42 is attached to one main surface of the high-frequency electrode 30 constituting the antenna 28 as in the example shown in FIG. The distances L ₃ and L ₄ between the main surface of both sides in the Y direction orthogonal to the longitudinal direction X (the same applies hereinafter) and the outer surface of the dielectric case 40 (that is, the outer surface of the side surface) opposite to each other are different ( In the illustrated example, L ₃ > L ₄ ), and it has been found that there is still room for improvement in that the density of the plasma 50 generated using the antenna 28 is different between the left and right sides of the antenna 28. This is because a thicker plasma 50 can be generated using a stronger magnetic field closer to the high frequency electrode 30 when the distance (L ₃ , L ₄ ) is smaller. That is, in the case of the antenna 28 shown in FIG. 5, the plasma 50 generated on the right side of the antenna 28 is darker than the plasma 50 generated on the left side.

  If there is a difference in plasma density between the left and right sides of the antenna 28 as described above, it causes a reduction in the uniformity of substrate processing in the left and right direction (ie, the Y direction).

Also in this case, if the distance L ₂ between the antenna 28 and the substrate 2 is increased, the diffusion of the plasma 50 in the Y direction increases until reaching the substrate 2, so that the density of the plasma density is reduced near the substrate 2. Although it is considered that the uniformity of the substrate processing can be improved, as described above, another problem that the distance between the antenna 28 and the substrate 2 is increased and the plasma processing apparatus is enlarged as described above. Occurs.

  Accordingly, an object of the present invention is to further improve the above points and to make the density of plasma generated using the above antenna uniform on the left and right sides of the antenna.

  Further, when a plurality of antennas 28 that are substantially straight in plane shape as described above are arranged in parallel along the surface of the substrate 2, for example, each antenna 28 is configured in detail. If a difference in impedance due to a difference in temperature of the high-frequency electrode 30 or a difference in impedance in the high-frequency power supply circuit to each antenna 28 occurs, the uniformity of the strength of the magnetic field generated by each antenna 28 is thereby reduced. Thus, there is still room for improvement in that the uniformity of plasma in the parallel direction of the plurality of antennas 28 may be reduced. Accordingly, it is another object of the present invention to further improve such points.

  One of the plasma processing apparatuses according to the present invention is an inductively coupled plasma in which an induction electric field is generated in a vacuum vessel by flowing a high-frequency current through an antenna, and a substrate is processed using the plasma. In the processing apparatus, the antenna has a structure in which a high-frequency electrode is housed in a dielectric case, and the high-frequency electrode includes two electrode conductors each having a rectangular plate shape as a rectangular plate as a whole. A reciprocating conductor structure in which the two ends of the electrode conductors are arranged parallel to each other with a gap therebetween, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. Currents are flowed in opposite directions, and further provided with notches facing each other across the gap on the gap-side sides of the two electrode conductors. A mouth portion is formed, and a plurality of openings are dispersed in the longitudinal direction of the high-frequency electrode, and the antenna is disposed in the vacuum vessel, and the main body of the high-frequency electrode constituting the antenna is formed. And the antenna has two high-frequency electrodes, and both high-frequency electrodes are disposed between the two high-frequency electrodes. And having a structure in which a cooling pipe through which a cooling medium flows is sandwiched in the dielectric case, and opposed to the main surface on the outer side of each high-frequency electrode The distance between the outer surface of the dielectric case is made substantially equal to each other for the two high-frequency electrodes.

  The antenna has two high-frequency electrodes, and a cooling pipe that cools the high-frequency electrode and into which a cooling medium flows is attached to one main surface of each high-frequency electrode. A plurality of high-frequency electrodes are housed in the dielectric case in a direction in which the cooling pipe is located inside, and the main surface on the outer side of each high-frequency electrode and the dielectric case opposite to the main surface You may employ | adopt the structure that the distance between an outer surface is mutually made substantially equal about the said 2 high frequency electrode.

  The antenna has a structure in which cooling pipes for cooling the high-frequency electrode and through which a cooling medium flows are attached to both main surfaces of the high-frequency electrode, and both the main surfaces of the high-frequency electrode and A structure may be employed in which the distances between the outer surfaces of the dielectric cases facing each other are substantially equal to each other.

  The antenna has a refrigerant passage through which a cooling medium for cooling the high-frequency electrode flows inside the high-frequency electrode constituting the antenna, and both the main surfaces of the high-frequency electrode and the dielectric case facing it A structure may be adopted in which the distances between the outer surfaces are substantially equal to each other.

  The high-frequency electrode constituting the antenna has two electrode conductors each bent in a U-shaped cross section, and the antenna is a dielectric having a cooling pipe sandwiched between the bent electrode conductors. The structure is housed in a body case, and the distance between the two main surfaces outside the high-frequency electrode and the outer surface of the dielectric case opposite to the main surface is substantially equal to each other. It may be adopted.

  Another one of the plasma processing apparatuses according to the present invention is an inductively coupled type in which an induction electric field is generated in a vacuum vessel by flowing a high-frequency current through an antenna, and plasma is generated and the substrate is processed using the plasma. The antenna has a structure in which a high-frequency electrode is housed in a dielectric case, and the high-frequency electrode is configured so that two electrode conductors form a rectangular plate shape as a whole. It has a reciprocating conductor structure in which a gap is placed close to each other and arranged in parallel, and one end in the longitudinal direction of both electrode conductors is connected by a conductor, and the high-frequency currents are opposite to each other in the two electrode conductors Further, notches facing each other across the gap are provided on the gap-side sides of the two electrode conductors, and an opening is formed by the facing notches. A plurality of openings are arranged in a distributed manner in the longitudinal direction of the high-frequency electrode, and the antenna is placed in the vacuum vessel, the main surface of the high-frequency electrode constituting the antenna, and the surface of the substrate Are arranged in a direction substantially perpendicular to each other, and the antenna has a substantially straight planar shape, a plurality of the antennas are arranged in parallel along the surface of the substrate, and A plurality of high-frequency power supplies that supply high-frequency power to the antennas, and a plurality of high-frequency power supplies that are provided at substantially the same location for the antennas and that detect the strength of the magnetic field generated by the antennas. In response to outputs from the magnetic sensor and the plurality of magnetic sensors, the high-frequency power output from the high-frequency power sources so that the outputs are substantially equal to each other. And a control device for controlling the force, is characterized in that.

  Instead of the plurality of magnetic sensors, a plurality of electric field sensors for detecting the strength of the electric field generated by each antenna may be provided.

  Instead of providing a plurality of high-frequency power supplies for supplying high-frequency power to each antenna, a high-frequency power supply for supplying high-frequency power to each antenna and the high-frequency power output from the high-frequency power supply are distributed to each antenna. In addition, a distribution circuit in which the magnitude of the high-frequency power distributed to each antenna is variable in response to an external control signal may be provided.

  According to the first aspect of the present invention, (a) the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other. Even if the density of the plasma occurs in the part corresponding to the center and both ends, the density of the plasma is positioned in the vertical direction with respect to the substrate surface, and the plasma is mixed with each other in the middle of the diffusion to the substrate side. Light and shade are easy to relax. In addition, the equipotential surface between the high-frequency electrode and the substrate has a curved surface with a valley below the high-frequency electrode except near the substrate, so that when the plasma diffuses to the substrate side, it tends to diffuse in the lateral direction. From the viewpoint, it becomes easy to relax the density of the plasma corresponding to the arrangement of the openings of the high-frequency electrode in the vicinity of the substrate.

  (B) As a result, even if the distance between the antenna and the substrate is not intentionally increased, the density of the plasma corresponding to the arrangement of the openings of the high-frequency electrodes constituting the antenna is relaxed in the vicinity of the substrate, so that The uniformity of substrate processing can be improved. Further, since it is not necessary to increase the distance between the antenna and the substrate, it is possible to prevent the vacuum vessel and thus the plasma processing apparatus from being enlarged.

  (C) Furthermore, the antenna has a structure in which two high-frequency electrodes are provided and a cooling pipe is sandwiched between the two high-frequency electrodes and is housed in a dielectric case. Since the distance between the outer main surface of each of the two and the outer surface of the dielectric case opposite to each other is substantially equal to each other for the two high-frequency electrodes, the density of the plasma generated using the antenna is reduced. Uniformity can be achieved on the left and right sides of the antenna.

  (D) As a result, the uniformity of the substrate processing can be improved also in the left-right direction of the antenna. Further, since it is not necessary to increase the distance between the antenna and the substrate, it is possible to prevent the vacuum vessel and thus the plasma processing apparatus from being enlarged.

  (E) That is, according to the present invention, as described above, the uniformity of the substrate processing in the longitudinal direction of the antenna can be improved, and the uniformity of the substrate processing can also be improved in the left-right direction of the antenna. Together, both effects can improve the uniformity of processing in two dimensions within the substrate surface without having to increase the distance between the antenna and the substrate.

  According to the invention described in claim 2, since the antenna is arranged in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Further, the antenna has two high-frequency electrodes, a cooling pipe is attached to one main surface of each high-frequency electrode, and the two high-frequency electrodes are arranged in the direction in which the cooling pipe is positioned inside the dielectric. The distance between the outer main surface of each high-frequency electrode and the outer surface of the dielectric case opposite to each other is substantially equal for the two high-frequency electrodes. Therefore, the density of plasma generated using the antenna can be made uniform on the left and right sides of the antenna.

  As a result, the same effects as the effects (d) and (e) of the invention described in claim 1 can be obtained.

  According to the invention described in claim 3, since the antenna is arranged in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Furthermore, the antenna has a structure in which cooling pipes are attached to both main surfaces of the high-frequency electrode, and the distance between both main surfaces of the high-frequency electrode and the outer surface of the dielectric case opposite to the main surface is substantially equal to each other. Therefore, the density of plasma generated using the antenna can be made uniform on the left and right sides of the antenna.

  As a result, the same effects as the effects (d) and (e) of the invention described in claim 1 can be obtained.

  According to the invention described in claim 4, since the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Further, the antenna has a refrigerant passage inside the high-frequency electrode constituting the antenna, and the distance between both main surfaces of the high-frequency electrode and the outer surface of the dielectric case facing it is substantially equal to each other. Since they are equal, the density of plasma generated using the antenna can be made uniform on the left and right of the antenna.

  As a result, the same effects as the effects (d) and (e) of the invention described in claim 1 can be obtained.

  According to the invention described in claim 5, since the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Furthermore, the high-frequency electrode constituting the antenna has two electrode conductors each bent in a U-shaped cross section, and the antenna is a dielectric having a cooling pipe sandwiched between the bent electrode conductors. The antenna has a structure housed in a body case, and the distance between the two main surfaces outside the high-frequency electrode and the outer surface of the dielectric case facing each other is substantially equal to each other. The density of the plasma generated using can be made uniform on the left and right sides of the antenna. As a result, the same effects as the effects (d) and (e) of the invention described in claim 1 can be obtained.

  (F) Further, since the two electrode conductors are bent as described above, the angular portion is reduced, and the electric field concentration around the high-frequency electrode can be reduced when the high-frequency power is turned on. As a result, the occurrence of abnormal discharge can be suppressed.

  According to the invention described in claim 6, since the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Furthermore, since a plurality of antennas having a substantially straight planar shape are arranged in parallel with each other along the surface of the substrate, a plasma with a larger area can be generated and a substrate with a larger area can be processed. it can.

  Further, in response to outputs from a plurality of magnetic sensors, the high-frequency power output from each high-frequency power source can be controlled so that the outputs are substantially equal to each other, thereby the magnetic field generated by each antenna. Therefore, the uniformity of plasma in the parallel direction of a plurality of antennas can be improved.

  (G) As a result, according to the present invention, as described above, the uniformity of the substrate processing in the longitudinal direction of the antenna can be improved, and the uniformity of the plasma can also be improved in the parallel direction of the plurality of antennas. Since the uniformity of processing can be improved, both effects can be combined, and the uniformity of processing in two dimensions within the substrate surface can be improved without intentionally increasing the distance between the antenna and the substrate.

  According to the invention described in claim 7, since the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Furthermore, since a plurality of antennas having a substantially straight planar shape are arranged in parallel with each other along the surface of the substrate, a plasma with a larger area can be generated and a substrate with a larger area can be processed. it can.

  Further, in response to outputs from a plurality of electric field sensors, the high frequency power output from each high frequency power supply can be controlled so that the outputs are substantially equal to each other, whereby the electric fields generated by the antennas are controlled. Therefore, the uniformity of plasma in the parallel direction of a plurality of antennas can be improved.

  As a result, the same effect as the effect (g) of the invention described in claim 6 can be obtained.

  According to the invention described in claim 8, since the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other, The same effects as shown in a) and (b) are obtained.

  Furthermore, since a plurality of antennas having a substantially straight planar shape are arranged in parallel with each other along the surface of the substrate, a plasma with a larger area can be generated and a substrate with a larger area can be processed. it can.

  Further, in response to the outputs from the plurality of magnetic sensors, the magnitude of the high-frequency power distributed to each antenna can be controlled by the distribution circuit so that the outputs are substantially equal to each other. Since the strength of the magnetic field generated by the antenna can be made uniform, the uniformity of plasma in the parallel direction of the plurality of antennas can be improved.

  As a result, the same effect as the effect (g) of the invention described in claim 6 can be obtained.

  According to the ninth aspect of the present invention, the antenna is disposed in a direction in which the main surface of the high-frequency electrode and the surface of the substrate are substantially perpendicular to each other. The same effects as shown in a) and (b) are obtained.

  Furthermore, since a plurality of antennas having a substantially straight planar shape are arranged in parallel with each other along the surface of the substrate, a plasma with a larger area can be generated and a substrate with a larger area can be processed. it can.

  Further, in response to outputs from the plurality of electric field sensors, the distribution circuit can control the magnitude of the high frequency power distributed to each antenna so that the outputs are substantially equal to each other. Since the strength of the electric field generated by the antenna can be made uniform, the uniformity of plasma in the parallel direction of the plurality of antennas can be improved.

  As a result, the same effect as the effect (g) of the invention described in claim 6 can be obtained.

It is a schematic perspective view which shows the antenna and board | substrate of a conventional plasma processing apparatus partially, and illustration of the dielectric material board is abbreviate | omitted. It is a figure which shows the schematic example of the equipotential surface between the antenna and board | substrate in the apparatus of FIG. 1, and the dielectric plate is also shown in figure. It is a figure which shows an example of the result of having measured the film thickness distribution of the film | membrane formed on the board | substrate with the apparatus of FIG. It is a schematic perspective view which shows partially the antenna and board | substrate of a plasma processing apparatus which concern on another application, and illustration of the dielectric material case is abbreviate | omitted. It is a figure which shows the schematic example of the equipotential surface between one antenna and a board | substrate in the apparatus of FIG. 4, and the dielectric material case is also illustrated. It is a figure which shows an example of the result of having measured the film thickness distribution of the film | membrane formed on the board | substrate with the apparatus of FIG. It is a schematic sectional drawing which shows one Embodiment of the plasma processing apparatus which concerns on this invention. FIG. 8 is a schematic cross-sectional view showing one antenna in the apparatus shown in FIG. 7 as viewed in the direction of the arrow HH. It is a front view of one high frequency electrode which comprises the antenna shown in FIG. 8, and illustration of the cooling pipe is abbreviate | omitted. It is sectional drawing which expands and shows one of the antennas in the apparatus shown in FIG. It is sectional drawing which shows the other example of an antenna, and respond | corresponds to FIG. It is sectional drawing which shows another example of an antenna, and respond | corresponds to FIG. It is sectional drawing which shows another example of an antenna, and respond | corresponds to FIG. FIG. 14 is a schematic cross-sectional view showing the antenna shown in FIG. 13 together with the vacuum container when viewed in the direction of the arrow II, and corresponds to FIG. It is sectional drawing which shows another example of an antenna, and respond | corresponds to FIG. It is a figure which shows an example of the apparatus which has arrange | positioned the several antenna in parallel, and the dielectric case of each antenna is abbreviate | omitting illustration. FIG. 17 is an enlarged side view showing one antenna and the periphery of the magnetic sensor in the apparatus shown in FIG. 16 when the sensor is a magnetic sensor, and a dielectric case is not shown. FIG. 18 is a cross-sectional view taken along line JJ in FIG. 17 and also shows a dielectric case. FIG. 17 is an enlarged side view showing one antenna and an electric field sensor in the apparatus shown in FIG. 16 when the sensor is an electric field sensor, and a dielectric case is not shown. FIG. 20 is a cross-sectional view taken along line KK in FIG. 19 and also shows a dielectric case. It is a figure which shows the other example of the apparatus which has arrange | positioned the several antenna in parallel, The dielectric material case of each antenna is abbreviate | omitting illustration.

  One embodiment of the plasma processing apparatus according to the present invention will be described with reference to FIGS. In the following description, the same reference numerals are assigned to the same or corresponding parts as those in the examples shown in FIGS.

  In order to indicate the orientation of the antenna 28 and the like, the X direction, the Y direction, and the Z direction that are orthogonal to each other at one point are shown in each drawing. The Z direction is a direction parallel to the perpendicular 3 standing on the surface of the substrate 2, and the Y direction is a direction perpendicular to the perpendicular 3, and these are simplified to represent the vertical direction Z and the horizontal direction Y, respectively. Sometimes called. The X direction is a direction orthogonal to the perpendicular 3 and is the longitudinal direction of the antenna 28. For example, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction, but is not limited thereto.

This apparatus, by generating an induced electric field into the vacuum chamber 4 by flowing a high frequency current I _R from the high frequency power source 60 to the antenna 28 to generate plasma 50 by the induced electric field, processing on a substrate 2 by using the plasma 50 Is an inductively coupled plasma processing apparatus.

  In this embodiment, the antenna 28 has a planar shape that is substantially straight in the X direction. In this application, “substantially straight” means not only literally a straight state but also a state close to straight (substantially straight state).

  A holder 10 that holds the substrate 2 is provided in the vacuum container 4.

  The substrate 2 is, for example, a substrate for a display device such as a liquid crystal display or an organic EL display, a flexible substrate for a flexible display, a substrate for a semiconductor device such as a solar cell, or the like, but is not limited thereto.

  The planar shape of the substrate 2 is, for example, a circle or a rectangle, and is not limited to a specific shape.

  The treatment applied to the substrate 2 is, for example, film formation by plasma CVD, etching, ashing, film formation by sputtering, or the like.

  This plasma processing apparatus is also called a plasma CVD apparatus when a film is formed by plasma CVD, a plasma etching apparatus when etching is performed, a plasma ashing apparatus when ashing is performed, and a plasma sputtering apparatus when sputtering is performed.

  The plasma processing apparatus includes, for example, a metal vacuum vessel 4, and the inside is evacuated through a vacuum exhaust port 8.

  A gas 24 is introduced into the vacuum vessel 4 through a gas introduction pipe 22. In this example, a plurality of gas introduction pipes 22 are arranged in the longitudinal direction X of each antenna 28.

The gas 24 may be set according to the processing content applied to the substrate 2. For example, when film formation is performed on the substrate 2 by plasma CVD, the gas 24 is a source gas. More specifically, when the source gas is SiH ₄ , an Si film is formed; when SiH ₄ + O ₂ is used, an SiO ₂ film is formed; when SiH ₄ + NH ₃ is used, an SiN: H film (silicon hydride film) is formed. When the source gas is SiF ₄ + N ₂ , SiN: F films (fluorinated silicon nitride films) can be formed on the surface of the substrate 2, respectively.

  In this embodiment, two antennas 28 are provided. However, the number of antennas 28 is one or more and arbitrary. Each antenna 28 has a structure in which the high-frequency electrode 30 is housed in a dielectric case (that is, a dielectric case) 40. The dielectric case 40 can prevent the surface of the high frequency electrode 30 and the like inside thereof from being sputtered by charged particles (mainly ions) in the plasma 50.

  The dielectric case 40 is made of, for example, ceramics such as quartz, alumina, silicon carbide, or a silicon plate.

  Then, the antenna 28 is placed in the vacuum container 4 so that the main surface of the high-frequency electrode 30 (that is, the larger surface of the plate-like object) and the surface of the substrate 2 are substantially perpendicular to each other. It is arranged in the direction. In this application, “substantially vertical” means not only literally a vertical state but also a state close to vertical (substantially vertical state).

  In this example, two openings 7 corresponding to the length of the antenna 28 are provided on the ceiling surface 6 of the vacuum vessel 4, and the antennas 28 are provided below the respective openings 7. In this example, the dielectric case 40 of each antenna 28 is fixed to the inner surface of the ceiling surface 6.

  Each opening 7 is covered with a cover plate 44, and a packing 52 for vacuum sealing is provided between each cover plate 44 and the ceiling surface 6. Feed throughs 46 and 47, which will be described later, pass through the respective cover plates 44, and a packing 53 for vacuum sealing is provided in the through part. Each cover plate 44 may be made of a dielectric such as quartz or alumina, or may be made of metal as long as electrical insulation of the through portions of the feedthroughs 46 and 47 is ensured. If it is made of metal, it becomes easy to prevent the high frequency from each antenna 28 from leaking outside through the opening 7.

  In this example, no vacuum seal packing is provided between the dielectric case 40 of each antenna 28 and the ceiling surface 6. Therefore, the inside of each dielectric case 40 becomes the atmosphere in the vacuum vessel 4 as well as the outside. Even in such a case, plasma is not generated in each dielectric case 40. This is because the space in each dielectric case 40 is small and the electron travel distance is not large enough to generate plasma. That is, the plasma 50 is generated outside each dielectric case 40 (see, for example, FIG. 7). However, a packing for vacuum sealing may be provided between the dielectric case 40 and the vacuum vessel 4 (more specifically, the ceiling surface 6), and the inside of the dielectric case 40 may be on the atmosphere side. In that case, the packing 53 is unnecessary. The same applies to other examples described later.

  Each high-frequency electrode 30 constituting each antenna 28 is formed so that the two electrode conductors 31 and 32 each having a rectangular plate shape that is long in the X direction form a rectangular plate shape as a whole (more specifically, The two electrode conductors 31 and 32 are close to each other with a gap 34 therebetween so that they are located on the same plane perpendicular to the surface of the substrate 2 (that is, on the same plane parallel to the XZ plane in this example). And arranged in parallel. In addition, one end in the longitudinal direction X of both electrode conductors 31 and 32 is connected by a conductor 33. Thereby, each high frequency electrode 30 has a reciprocating conductor structure. In this example, the conductor 33 is integral with the electrode conductors 31 and 32, but may be separate. A cooling pipe 42 described later may also serve as the conductor 33. The same applies to the antennas 28 of other examples described later.

  The material of each of the electrode conductors 31 and 32 and the conductor 33 is, for example, copper (more specifically, oxygen-free copper), aluminum, or the like, but is not limited thereto.

  Notches 35 facing the gap 34 side (in other words, the inner side) 31a, 32a (see FIG. 9) of the two electrode conductors 31, 32 constituting each high-frequency electrode 30 with the gap 34 interposed therebetween, 36 are provided, and the opening 37 is formed by the notches 35 and 36 facing each other. A plurality of the openings 37 are dispersed in the longitudinal direction X of the antenna 28. The number of openings 37 is not limited to the example shown in the drawing. The same applies to the antennas 28 of other examples described later.

  Each notch 35, 36 is preferably symmetrical about the gap 34. The shape of each opening 37 may be circular as shown in the illustrated example, or may be rectangular.

  Further, in this embodiment, each antenna 28 has two high-frequency electrodes 30 having the same structure, and cools both high-frequency electrodes 30 between the two high-frequency electrodes 30. A structure in which a cooling pipe 42 through which a cooling medium (for example, cooling water) flows is sandwiched in a dielectric case 40 is provided. The two high frequency electrodes 30 are disposed substantially parallel to each other.

  The openings 37 of the two (in other words, left and right) high-frequency electrodes 30 are preferably provided at positions facing each other. In this example, the openings 37 do so. The same applies to other examples described later.

  The cooling pipe 42 has a portion extending along the longitudinal direction X of both the high-frequency electrodes 30 while avoiding the openings 37 of the two high-frequency electrodes 30 (see FIG. 8). The cooling pipe 42 is attached to the two high-frequency electrodes 30 (in other words, two high-frequency electrodes 30 on both sides of the cooling pipe 42), for example, by a joining means such as brazing. The cooling pipe 42 is a metal pipe, for example. The same applies to other examples described later. 8 is a view shown in the direction of the arrow H-H in FIG. 7, the antenna 28 shown in FIG. 8 removes the other high-frequency electrode 30 stacked from the upper side of the drawing. It is shown.

Further, referring to FIG. 10, in each antenna 28, the outer main surface of each of the two high-frequency electrodes 30 and the outer surface of dielectric case 40 (that is, the outer surface of the side surface; the same applies hereinafter) facing each other. The distances L ₅ and L ₆ between them are substantially equal to each other for the two high-frequency electrodes 30 (ie, L ₅ = L ₆ or L ₅ ≈L ₆ ).

  For example, high frequency power is supplied in parallel to the plurality of antennas 28 from a common high frequency power supply 60 via a common matching circuit 62 as in the examples shown in FIGS. However, the matching circuit 62 may be individually provided for each antenna 28, and the high frequency power supply 60 may be provided for each antenna 28. The same applies to other examples described later.

  The frequency of the high-frequency power output from the high-frequency power supply 60 is, for example, a general 13.56 MHz, but is not limited thereto.

  High frequency power is supplied in parallel from a high frequency power supply 60 to the two high frequency electrodes 30 constituting each antenna 28 through feedthroughs 46 and 47. That is, the feedthroughs 46 and 47 are common to the two high-frequency electrodes 30 in this example.

Further, the two electrode conductors 31 and 32 constituting each high-frequency electrode 30 are supplied with high-frequency power from the high-frequency power source 60 through the feedthroughs 46 and 47, and thereby the two electrode conductors 31 and 32 are supplied to the two electrode conductors 31 and 32. the opposite of the high frequency current (return current) I _R is flowed together (as described above, because the high-frequency direction of the high-frequency current I _R is inverted by the time.). More specifically, the end of the electrode conductor 31 on one side having a reciprocating conductor structure on the side opposite to the conductor 33 is a feeding point for high-frequency power (that is, a point connected to the high-frequency power source 60; the same applies hereinafter). ) 48, and the other end of the electrode conductor 32 opposite to the conductor 33 is a ground point (that is, a point connected to the ground; the same applies hereinafter) 49.

  A cooling medium flows through the feedthroughs 46 and 47 through the cooling pipe 42. That is, the feedthroughs 46 and 47 are commonly used for supplying high-frequency power and cooling medium.

By flowing the high-frequency current I _R to each high-frequency electrode 30 constituting each antenna 28 as described above, a high-frequency magnetic field is generated around each high-frequency electrode 30, thereby causing an induction electric field in a direction opposite to the high-frequency current I _R. Occurs. Due to this induced electric field, electrons are accelerated in the vacuum vessel 4 to ionize the gas 24 in the vicinity of the antenna 28 and generate a plasma 50 in the vicinity of the outside of the dielectric case 40. The plasma 50 diffuses to the vicinity of the substrate 2, and the plasma 2 can be subjected to the above-described processing such as film formation.

  Also in the plasma processing apparatus of this embodiment, each high-frequency electrode 30 constituting each antenna 28 has a reciprocating conductor structure when viewed globally, and a plurality of openings 37 are formed in each high-frequency electrode 30 in the longitudinal direction X. Since the structure is arranged in a distributed manner, the same effect as the effect obtained by the conventional plasma processing apparatus described above with reference to FIGS. 1 to 3 can be obtained.

That is, the antenna 28 (more specifically its high-frequency electrode 30) is flowed into the high-frequency current I _R is opposite to each other on the two electrode conductors 31 and 32 have a round trip conductor structure global point of view Therefore, the effective inductance of the antenna 28 is reduced by the mutual inductance existing between the reciprocating conductors 31 and 32.

More specifically, the total impedance Z _T of parallel reciprocating conductors that are close to each other is expressed by the following equation as described in electrical theory books as differential connections. Here, in order to simplify the description, the resistance of each conductor is R, the self-inductance is L, and the mutual inductance between the two conductors is M.

[Equation 1]
Z _T = 2R + j2 (LM)

Inductance L _T of the total impedance Z _T is expressed by the following equation. As in the inductance L _T, a material obtained by combining the self and mutual inductances, in this specification will be referred to as effective inductance.

[Equation 2]
L _T = 2 (LM)

As can be seen from the above equation, the effective inductance L _T of the reciprocating conductor is smaller sentence of the mutual inductance M, and thus also decreases total impedance Z _T. This principle is also applied to the antenna 28 having a reciprocating conductor structure.

  As a result of the effective inductance of the antenna 28 being reduced by the above principle, the potential difference generated between both ends in the longitudinal direction X of the antenna 28 can be suppressed smaller than that of a simple flat antenna, thereby reducing the plasma potential. In addition, the uniformity of the plasma density distribution in the longitudinal direction X of the antenna 28 can be enhanced.

  As a result of suppressing the plasma potential to a low level, the energy of charged particles incident on the substrate 2 from the plasma 50 can be suppressed to a low level. For this reason, for example, damage to the film formed on the substrate 2 can be suppressed to a low level. Improvements can be made. Further, even when the antenna 28 is lengthened, for the above reason, the potential of the antenna 28 can be kept low and the plasma potential can be kept low. Therefore, the antenna 28 can be lengthened to easily cope with the increase in size of the substrate 2. Become.

  As a result of improving the uniformity of the plasma density distribution in the longitudinal direction X of the antenna 28, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved. For example, the uniformity of the film thickness distribution in the longitudinal direction X of the antenna 28 can be improved.

When the high-frequency current I _R flowing through each high-frequency electrode 30 is viewed in detail, as shown in the example of FIG. 9, the high-frequency current I _R is mainly caused by the skin effect, and the end portions of the two electrode conductors 31, 32. Tend to flow through. Among them, when attention is paid to the sides 31a and 32a on the gap 34 side of the two electrode conductors 31 and 32, the high-frequency current I _R flows in the opposite direction to the sides close to each other. In comparison with the sides 31b and 32b, the inductance (and hence the impedance) becomes smaller. Therefore, the high-frequency current I _R will flow more along the opening 37 formed therein sides and the clearance 34 side. As a result, each opening 37 functions in the same manner as the coils distributed in the longitudinal direction X of the antenna 28, so that a structure similar to that in which a plurality of coils are connected in series can be formed with a simple structure. it can. Therefore, with a simple structure, a strong magnetic field can be generated in the vicinity of each opening 37 to increase the plasma generation efficiency.

Even if the cooling pipe 42 is attached to the high-frequency electrode 30 by brazing or the like, the inductance (and hence the impedance) on the side on the gap 34 side is small as described above, and the high-frequency current I _R is on the side on the gap 34 side and there. Since many flows along the formed openings 37, it does not hinder the generation of a strong magnetic field in the vicinity of each opening 37.

  Furthermore, according to the plasma processing apparatus according to this embodiment, the antenna 28 is disposed in the vacuum vessel 4 in a direction in which the main surface of the high-frequency electrode 30 and the surface of the substrate 2 are substantially perpendicular to each other. Therefore, for the same reason as in the case of the plasma processing apparatus according to another application described above with reference to FIGS. 4 to 6, the antenna 28 is configured without increasing the distance between the antenna 28 and the substrate 2. The density of the plasma corresponding to the arrangement of the opening 37 of the high-frequency electrode 30 can be relaxed in the vicinity of the substrate 2 and the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved. The details of this effect will be described with reference to the above description of another application, and is summarized as follows.

  That is, since the antenna 28 is arranged so that the main surface of the high-frequency electrode 30 and the surface of the substrate 2 are substantially perpendicular to each other, it corresponds to the center and both ends of each opening 37 of the high-frequency electrode 30. Even if the density of the plasma is generated in the portion where the plasma is generated, the density of the plasma is positioned in the vertical direction with respect to the substrate surface, and the plasma 50 is mixed with each other in the middle of diffusion to the substrate 2 side, so that the density is easily relaxed. . In addition, since the equipotential surface between the high-frequency electrode 30 and the substrate 2 has a curved surface with a valley below the high-frequency electrode 30 except near the substrate, the plasma 50 diffuses in the lateral direction when diffusing to the substrate side. From this point of view, it becomes easy to relax the density of the plasma corresponding to the arrangement of the opening 37 of the high-frequency electrode 30 in the vicinity of the substrate 2.

  As a result, even if the distance between the antenna 28 and the substrate 2 is not intentionally increased, the density of the plasma corresponding to the arrangement of the openings 37 of the high-frequency electrode 30 constituting the antenna 28 is relaxed in the vicinity of the substrate 2, and the antenna 28. The uniformity of substrate processing in the longitudinal direction X can be improved. Furthermore, since it is not necessary to darely increase the distance between the antenna 28 and the substrate 2, it is possible to prevent the vacuum vessel 4 and hence the plasma processing apparatus from being enlarged.

Further, mainly referring to FIG. 10, the antenna 28 has two high-frequency electrodes 30 and a cooling pipe 42 sandwiched between the two high-frequency electrodes 30 in the dielectric case 40. The distances L ₅ and L ₆ between the outer main surface of each high-frequency electrode 30 and the outer surface of the dielectric case 40 facing the high-frequency electrode 30 are set to each other with respect to the two high-frequency electrodes 30. Since they are substantially equal, the density of the plasma 50 generated using the antenna 28 can be made uniform on the left and right sides of the antenna 28. This is because the distances L ₅ and L ₆ are substantially equal to each other, so that the strength of the magnetic field generated by the two high-frequency electrodes 30 is also substantially equal in the vicinity of the left and right side surfaces of the dielectric case 40. This is because the densities of the plasma 50 generated in the vicinity of the left and right side surfaces of the dielectric case 40 are substantially equal to each other.

  As a result, the uniformity of the substrate processing can be improved also in the left-right direction Y of the antenna 28. Furthermore, it is not necessary to increase the distance between the antenna 28 and the substrate 2 (see FIG. 7; the same applies hereinafter) in order to increase the plasma density mitigation effect due to plasma diffusion, so that the vacuum vessel 4 and thus the plasma processing apparatus can be increased in size. Can be prevented.

  That is, according to this embodiment, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the substrate processing can also be improved in the left-right direction Y of the antenna 28. Therefore, by combining both the effects, it is possible to improve the uniformity of the processing in two dimensions within the substrate plane without intentionally increasing the distance between the antenna 28 and the substrate 2.

  Next, in another example of the antenna 28, the same or corresponding parts as those in the example shown in FIG. 10 are denoted by the same reference numerals, and the differences from the example shown in FIG. 10 will be mainly described below. .

  The antenna 28 in the example shown in FIG. 11 has two high-frequency electrodes 30 having the above-described structure, the cooling pipe 42 having the above-described structure is attached to one main surface of each high-frequency electrode 30, and the two sheets The high-frequency electrode 30 is housed in the dielectric case 40 in such a direction that the cooling pipe 42 is located inside. The two high frequency electrodes 30 are disposed substantially parallel to each other. Each cooling pipe 42 has a portion extending along the longitudinal direction X of the high-frequency electrode 30 while avoiding the openings 37 of the high-frequency electrode 30 to which the cooling pipe 42 is attached (see FIG. 8).

Furthermore, the distances L ₇ and L ₈ between the outer main surface of each high-frequency electrode 30 and the outer surface of the dielectric case 40 facing it are made substantially equal to each other for the two high-frequency electrodes 30. (Ie L ₇ = L ₈ or L ₇ ≈L ₈ ).

  The two high-frequency electrodes 30 constituting the antenna 28 are supplied with high-frequency power in parallel from the above-described high-frequency power source 60 through, for example, two sets of the feedthroughs 46 and 47 described above. The high-frequency power supply to the two electrode conductors 31 and 32 constituting each high-frequency electrode 30 is the same as in the above-described example. The cooling medium is supplied to the two cooling pipes 42 using the two sets of feedthroughs 46 and 47.

Also in this example, as described above, the distances L ₇ and L ₈ between the outer main surface of each high-frequency electrode 30 and the outer surface of the dielectric case 40 opposed thereto are substantially equal to each other. Similarly to the case of the above-described example, the density of the plasma 50 generated using the antenna 28 can be made uniform on the left and right sides of the antenna 28.

  As a result, the uniformity of the substrate processing can be improved also in the left-right direction Y of the antenna 28. Furthermore, since it is not necessary to deliberately increase the distance between the antenna 28 and the substrate 2 in order to enhance the plasma density mitigation effect due to plasma diffusion, it is possible to prevent the vacuum vessel 4 and thus the plasma processing apparatus from being enlarged.

  That is, according to the embodiment using the antenna 28, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be enhanced as described above, and the uniformity of the substrate processing in the left-right direction Y of the antenna 28 is also possible. Therefore, both the effects can be combined, and the uniformity of the processing in two dimensions within the substrate surface can be improved without having to increase the distance between the antenna 28 and the substrate 2.

  The antenna 28 in the example shown in FIG. 12 has a structure in which the cooling pipes 42 having the above structure are attached to both main surfaces of the high frequency electrode 30 having the above structure. The cooling pipes 42 on both main surfaces respectively have portions extending along the longitudinal direction X of the high-frequency electrode 30 while avoiding the openings 37 of the high-frequency electrode 30 (see FIG. 8). It is preferable that the diameters of the cooling pipes 42 on both main surfaces be substantially equal to each other, so that the left-right symmetry of the structure in the dielectric case 40 is improved.

Further, the distances L ₉ and L ₁₀ between both main surfaces of the high-frequency electrode 30 and the outer surface of the dielectric case 40 facing the high-frequency electrode 30 are substantially equal to each other (ie, L ₉ = L ₁₀ or L ₉ ≈ L ₁₀ ).

  The high-frequency power from the above-described high-frequency power supply 60 is supplied in parallel to both main surfaces of the high-frequency electrode 30 using, for example, two sets of the feedthroughs 46 and 47 described above. However, since the high-frequency electrode 30 is usually thin, high-frequency power may be supplied to only one main surface thereof. The high-frequency power supply to the two electrode conductors 31 and 32 constituting the high-frequency electrode 30 is the same as in the above-described example. The cooling medium is supplied to the two cooling pipes 42 using the two sets of feedthroughs 46 and 47.

Also in this example, as described above, the distances L ₉ and L ₁₀ between the outer main surface of the high-frequency electrode 30 and the outer surface of the dielectric case 40 opposed thereto are substantially equal to each other. As in the case of the example described above, the density of the plasma 50 generated using the antenna 28 can be made uniform on the left and right sides of the antenna 28.

  In addition, a part of the high-frequency current flows through the cooling pipes 42 on both main surfaces of the high-frequency electrode 30, which may contribute to generation of a high-frequency magnetic field and thus to generation of the plasma 50. Since the distance between the cooling pipe 42 on the surface and the dielectric case 40 opposite thereto is also substantially equal to each other, this also equalizes the density of the plasma 50 generated using the antenna 28 on the left and right sides of the antenna 28. Contributes to

  As a result, the uniformity of the substrate processing can be improved also in the left-right direction Y of the antenna 28. Furthermore, since it is not necessary to deliberately increase the distance between the antenna 28 and the substrate 2 in order to enhance the plasma density mitigation effect due to plasma diffusion, it is possible to prevent the vacuum vessel 4 and thus the plasma processing apparatus from being enlarged.

  That is, according to the embodiment using the antenna 28, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be enhanced as described above, and the uniformity of the substrate processing in the left-right direction Y of the antenna 28 is also possible. Therefore, both the effects can be combined, and the uniformity of the processing in two dimensions within the substrate surface can be improved without having to increase the distance between the antenna 28 and the substrate 2.

  The antenna 28 in the example shown in FIG. 13 has a structure in which a refrigerant passage 43 through which a cooling medium for cooling the high-frequency electrode 30 flows is provided inside the high-frequency electrode 30 having the above structure. The refrigerant passage 43 has a portion that extends along the longitudinal direction X of the high-frequency electrode 30 while avoiding the openings 37 of the high-frequency electrode 30 (see FIG. 14).

Furthermore, the distances L ₁₁ and L ₁₂ between both main surfaces of the high-frequency electrode 30 and the outer surface of the dielectric case 40 facing the high-frequency electrode 30 are substantially equal to each other (ie, L ₁₁ = L ₁₂ or L ₁₁ ≈ L ₁₂ ).

  The supply of high-frequency power from the high-frequency power source 60 to the high-frequency electrode 30 constituting the antenna 28 and the supply of the cooling medium to the refrigerant passage 43 in the high-frequency electrode 30 are performed through the feedthroughs 46 and 47 described above. The high-frequency power supply to the two electrode conductors 31 and 32 constituting the high-frequency electrode 30 is the same as in the above-described example.

Also in this example, the distances L ₁₁ and L ₁₂ between the outer main surface of the high-frequency electrode 30 and the outer surface of the dielectric case 40 facing the same are substantially equal to each other as described above. As in the case of the example described above, the density of the plasma 50 generated using the antenna 28 can be made uniform on the left and right sides of the antenna 28.

  As a result, the uniformity of the substrate processing can be improved also in the left-right direction Y of the antenna 28. Furthermore, since it is not necessary to deliberately increase the distance between the antenna 28 and the substrate 2 in order to enhance the plasma density mitigation effect due to plasma diffusion, it is possible to prevent the vacuum vessel 4 and thus the plasma processing apparatus from being enlarged.

  That is, according to the embodiment using the antenna 28, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be enhanced as described above, and the uniformity of the substrate processing in the left-right direction Y of the antenna 28 is also possible. Therefore, both the effects can be combined, and the uniformity of the processing in two dimensions within the substrate surface can be improved without having to increase the distance between the antenna 28 and the substrate 2.

  The antenna 28 in the example shown in FIG. 15 is a modification of the example shown in FIG. 10, and as a pair of electrode conductors constituting the high-frequency electrode 30, a pair of upper and lower electrodes each bent in a U-shaped cross section. The conductors 31 and 32 are provided, and the two sides of the one electrode conductor 31 opposite to the bent portion 31c and the two sides of the other electrode conductor 32 opposite to the bent portion 32c are spaced from each other. (For example, see the gap 34 in FIG. 8). The bent portions 31c and 32c are bent in a round shape. In this application, the structure of the high-frequency electrode 30 is also included in the structure in which the two electrode conductors 31 and 32 are arranged parallel to each other with a gap therebetween so as to form a rectangular plate shape as a whole. Yes.

The high-frequency electrode 30 also have a reciprocating conductor structure one end to each other in the longitudinal direction X are connected by conductors of the electrodes conductors 31 and 32, the high frequency current I _R is opposite to each other to the two electrodes conductors 31 and 32 Flowed in the direction. In addition, notches (for example, see notches 35 and 36 in FIG. 8) facing each other with the gap between the opposing sides of the electrode conductors 31 and 32 are provided, and openings are formed by the facing notches. 37 is formed, and a plurality of the openings 37 are dispersed in the longitudinal direction X of the high-frequency electrode 30 and arranged. The left and right openings 37 of the high-frequency electrode 30 are preferably provided at positions facing each other, and in this example, such is the case.

  Further, the antenna 28 is configured to cool the high-frequency electrode 30 between the electrode conductors 31 and 32 bent in the U-shaped cross section and sandwich the cooling pipe 42 through which the cooling medium flows. The dielectric case 40 is housed in a structure. The cooling pipe 42 has a portion extending along the longitudinal direction X of the high-frequency electrode 30 while avoiding the openings 37 of the high-frequency electrode 30 (see the cooling pipe 42 in FIG. 8). The cooling pipe 42 is attached to the electrode conductors 31 and 32 by a joining means such as brazing.

Further, in the antenna 28, the distances L ₁₃ and L ₁₄ between the two main surfaces outside the high-frequency electrode 30 and the outer surface of the dielectric case 40 facing the main surface are substantially equal to each other (ie, L ₁₃ = L ₁₄ or L ₁₃ ≈L ₁₄ ).

  The high frequency electrode 30 constituting the antenna 28 is supplied with high frequency power from the above described high frequency power supply 60 through, for example, the above described feedthroughs 46 and 47. A cooling medium is supplied to the cooling pipe 42 using the feedthroughs 46 and 47.

Also in this example, as described above, the distances L ₁₃ and L ₁₄ between the two main surfaces outside the high-frequency electrode 30 and the outer surface of the dielectric case 40 facing each other are made substantially equal to each other. Therefore, as in the case of the example described above, the density of the plasma 50 generated using the antenna 28 can be made uniform on the left and right sides of the antenna 28.

  As a result, the uniformity of the substrate processing can be improved also in the left-right direction Y of the antenna 28. Furthermore, since it is not necessary to deliberately increase the distance between the antenna 28 and the substrate 2 in order to enhance the plasma density mitigation effect due to plasma diffusion, it is possible to prevent the vacuum vessel 4 and thus the plasma processing apparatus from being enlarged.

  That is, according to the plasma processing apparatus using the antenna 28, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the substrate processing can also be performed in the left-right direction Y of the antenna 28. Therefore, even if both the effects are combined and the distance between the antenna 28 and the substrate 2 is not increased, the processing uniformity in two dimensions within the substrate surface can be improved.

  Furthermore, since the two electrode conductors 31 and 32 constituting the high-frequency electrode 30 are bent as described above, at least the bent portions 31c and 32c have no angular portions. Accordingly, the angular portion is reduced, and the electric field concentration around the high-frequency electrode 30 when the high-frequency power is input can be reduced. As a result, the occurrence of abnormal discharge can be suppressed.

  The cooling pipe 42 may be provided on the inner surface of the bent portions 31c and 32c of the electrode conductors 31 and 32 as in this example, and attached so as to realize heat transfer with the inner surface. Instead, it may be attached away from the inner surface of the bent portions 31c and 32c. When the cooling pipe 42 is attached to the inner surfaces of the bent portions 31c and 32c, for example, a bending diameter corresponding to the outer diameter of the cooling pipe 42 is provided on the inner surfaces of the bent portions 31c and 32c, and the cooling pipe is attached to the inner surfaces. What is necessary is just to attach 42 by joining means, such as brazing.

  When the cooling pipe 42 is attached to the inner surfaces of the bent portions 31c and 32c as described above, the heat transfer area between the cooling pipe 42 and the electrode conductors 31 and 32 is increased, so that the cooling performance of the high-frequency electrode 30 is improved. .

  Further, for example, compared to the case where the cooling pipe 42 is sandwiched between the two flat plate-like high-frequency electrodes 30 as in the example shown in FIG. 10, the bent electrode conductors 31 and 32 as in the example shown in FIG. When the cooling pipe 42 is attached to the inner surface of the bent portions 31c and 32c, the workability at the time of joining work by brazing the cooling pipe 42 to the electrode conductors 31 and 32 is improved, so that the working time and work auxiliary jig are improved. In view of the above, it is possible to reduce the processing cost.

  The antenna 28 in each of the above embodiments is not limited to a straight planar shape, and the planar shape may be other shapes such as a curved shape or an annular shape.

  Next, an embodiment in which a plurality of antennas 28 each having a substantially straight planar shape are arranged in parallel along the surface of the substrate 2 will be described. In the following, the same or corresponding parts as those of the previous embodiment shown in FIGS. 7 to 9 and the like are denoted by the same reference numerals, and differences from the previous embodiment will be mainly described.

  As in the embodiment shown in FIG. 16, a plurality of antennas 28 whose planar shapes are substantially straight in the X direction are arranged in parallel in the Y direction and in parallel with each other along the surface of the substrate 2 (more specifically, in parallel with each other). ) May be arranged. By doing so, a plasma having a larger area can be generated and the substrate 2 having a larger area can be processed. In FIG. 16, four antennas 28 are shown for simplification of illustration, but the number of antennas 28 is not limited thereto. The same applies to the embodiment of FIG. 21 described later.

  In the embodiment shown in FIG. 16, each antenna 28 has a dielectric case 40 (FIG. 18) in which a cooling pipe 42 is attached to one main surface of the high-frequency electrode 30, as in the case of another application shown in FIG. (Refer to FIG. 7 to FIG. 15.) The antenna 28 described with reference to FIGS. The high frequency power is supplied to the high frequency electrode 30 of each antenna 28 and the cooling medium is supplied to each cooling pipe 42 through the feedthroughs 46 and 47 described above. The same applies to the embodiment shown in FIG. 21 described later.

  In any case, also in this embodiment, each antenna 28 is arranged in a direction in which the main surface of the high-frequency electrode 30 and the surface of the substrate 2 are substantially perpendicular to each other. By adopting, the above-described effects can be achieved.

  Further, the plasma processing apparatus shown in FIG. 16 is provided with a plurality of high-frequency power sources 60 for supplying high-frequency power to the respective antennas 28 and the respective antennas 28 provided at substantially the same location. In response to outputs from the plurality of magnetic sensors 90 that detect the strength of the magnetic field, and the outputs from the plurality of magnetic sensors 90, the high-frequency signals output from the high-frequency power sources 60 so that the outputs are substantially equal to each other. And a control device 100 that controls electric power.

  A matching circuit 62 may be provided between each high-frequency power source 60 and each antenna 28 as necessary.

  Each magnetic sensor 90 (and each electric field sensor 94 described later) is shown in a simplified manner in FIG. The same applies to FIG. 21 described later. A more specific example of the magnetic sensor 90 will be described with reference to FIGS. In FIG. 17, in order to mainly represent the core wire 92, the dielectric 93 is not shown, and the conductor tube 91 is indicated by a broken line. Refer to FIG. 18 for these details.

Each magnetic sensor 90 has a structure in which a core wire (conducting wire) 92 is passed through the central axis of a conductor tube 91 having a generally loop shape, and a dielectric 93 is packed therebetween to be electrically insulated. The conductor tube 91 is open at one place so as not to form a closed circuit, and is electrically grounded at one place. The core wire 92 also has a generally loop shape, and the output S ₁ (or S ₂ , S ₃ , S ₄ ) is taken out from both ends thereof. Although the conductor tube 91 is not necessarily provided, it is preferable to provide the conductor tube 91. In such a case, the conductor tube 91 shields the electric field, and the core wire 92 is not easily affected by the electric field.

  Such a magnetic sensor 90 is arranged in the vicinity of the high-frequency electrode 30 and so as to be substantially parallel to the main surface of the high-frequency electrode 30 (more specifically, the circular surface of the core 92 is the main surface of the high-frequency electrode 30). To be substantially parallel to each other). Such an arrangement increases the output of the magnetic sensor 90. With such an arrangement, the magnetic sensor 90 may be arranged anywhere in the high-frequency electrode 30, but the magnetic sensor 90 is located in the opening 37 because the magnetic field near the opening 37 of the high-frequency electrode 30 is strong as described above. It is preferable to arrange them at opposite positions, and more preferably to arrange them coaxially with the center of the opening 37. By doing so, the output of the magnetic sensor 90 becomes larger. However, in any case, each magnetic sensor 90 is disposed in substantially the same place and in the same state with respect to each antenna 28 (more specifically, the high-frequency electrode 30). Thereby, the conditions of magnetic field detection by each magnetic sensor 90 can be made uniform.

  Each magnetic sensor 90 may be attached to the inner surface of each dielectric case 40 as in the example shown in FIG.

When high-frequency power is supplied to each antenna 28 (more specifically, the high-frequency electrode 30) and a high-frequency current I _R flows as described above, a high-frequency magnetic field is generated around each high-frequency electrode 30, which is A high-frequency voltage is induced in each core wire 92 in accordance with the time variation of the interlinkage magnetic flux by electromagnetic induction in linkage with the magnetic sensor 90 (more specifically, the core wire 92), and this is output S ₁ (or S ₂ , S ₃ , S ₄ ). These outputs S _{1 to} S ₄ may be supplied to the control device 100 as they are, or provided with signal converters 98 in the middle, and converted into signals that can be easily handled by the control device 100 (for example, direct current or direct current voltage). May be supplied to the control device 100.

The control device 100 controls the high-frequency power output from each high-frequency power supply 60 so that the outputs S _{1 to} S ₄ from each magnetic sensor 90 (or signals obtained by converting them) are substantially equal to each other. . For example, if the output from the magnetic sensor 90 is smaller than the others, the high frequency power supplied to the antenna 28 provided with the magnetic sensor 90 is increased, and the output from the magnetic sensor 90 is substantially equal to the others. To be. The same applies to the reverse case.

  By the above control, for example, even if there is a difference in impedance due to a difference in temperature rise of the high-frequency electrode 30 constituting each antenna 28, a difference in impedance in a high-frequency power supply circuit to each antenna 28, etc., each antenna 28 is generated. Since the strength of the magnetic field to be generated can be made uniform, the uniformity of plasma in the parallel direction Y of the plurality of antennas 28 can be improved.

  Moreover, the above control can be performed in real time during the generation of the plasma 50.

  As a result, according to the plasma processing apparatus of this embodiment, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the plasma can also be achieved in the parallel direction Y of the plurality of antennas 28. Therefore, it is possible to improve the uniformity of the substrate processing, so that both effects can be combined and the two-dimensional processing in the substrate plane can be performed without increasing the distance between the antenna 28 and the substrate 2. Uniformity can be improved.

  Each antenna 28 is provided with a plurality of magnetic sensors 90, and the output from the plurality of magnetic sensors 90 of each antenna 28 (for example, an average value) is given to the control device 100, respectively. You may make it control the high frequency electric power output from each high frequency power supply 60 so that the said synthesized value may become substantially equal about each antenna 28, respectively.

  When a plurality of antennas 28 are arranged in parallel as described above, all the antennas 28 may be arranged at equal intervals, and the plasma density in both end regions in the parallel direction Y of the plurality of antennas 28 is lower than the other. In consideration of this tendency, the distance between both end regions in the parallel direction Y of the plurality of antennas 28 may be set smaller than the others.

  An electric field sensor 94 may be provided in place of the magnetic sensor 90, and an example in that case will be described with reference to FIGS. In FIG. 19, the dielectric 96 is not shown in order to mainly represent the electrode plate 95. Refer to FIG. 20 for these details.

  Each electric field sensor 94 has a structure in which an electrode plate 95 is covered with a dielectric 96. The planar shape of the electrode plate 95 is shown as an example of a circle in FIG. 19, but other shapes such as a quadrangle may be used. Although it is not always necessary to provide the dielectric 96, it is preferable to provide it. In this case, even if the electric field sensor 94 is disposed near the high-frequency electrode 30, the electrode plate 95, the high-frequency electrode 30, and the cooling are provided. It is possible to prevent discharge from occurring between the pipe 42 and the pipe 42.

  Such an electric field sensor 94 is arranged in the vicinity of the high-frequency electrode 30 and substantially parallel to the main surface of the high-frequency electrode 30 (more specifically, the electrode plate 95 is substantially in contact with the main surface of the high-frequency electrode 30. To be parallel). Such an arrangement increases the output of the electric field sensor 94. With such an arrangement, the electric field sensor 94 may be arranged anywhere on the high-frequency electrode 30, but the potential near the feeding point 48 (see FIGS. 8 and 9) of the high-frequency electrode 30 is the highest and easy to detect. Therefore, it is preferable to dispose near the end on the feeding point 48 side. However, in any case, each electric field sensor 94 is disposed in substantially the same place in the same state with respect to each antenna 28 (more specifically, the high-frequency electrode 30). Thereby, the conditions for electric field detection by each electric field sensor 94 can be made uniform.

  Each electric field sensor 94 may be attached to the inner surface of each dielectric case 40 as in the example shown in FIG.

If (more specifically its high-frequency electrode 30) each antenna 28 high frequency current I _R is supplied to the high-frequency power in the manner described above, when the impedance of the high-frequency electrode 30 and Z, the high-frequency electrode 30 is high frequency voltage V is generated represented by V = Z · I _R. The magnitude of the high frequency voltage V is distributed along the current path of the high frequency electrode 30. This high frequency voltage V becomes the source of the electric field generated by each antenna 28. Such a high-frequency voltage V also contributes to the generation of the plasma 50 even if it is not as large as the magnetic field generated by the antenna 30. This is called capacitive coupling. Therefore, the high frequency voltage V generated by each antenna 28, that is, the strength of the electric field is detected and controlled so that they are substantially equal. The uniformity of the plasma in the parallel direction Y of the plurality of antennas 28 is also possible. It contributes to improving.

In each electric field sensor 94 (more specifically, the electrode plate 95), a high frequency voltage corresponding to the magnitude of the high frequency voltage V is induced by capacitive coupling, which is output S ₁ (or S ₂ , S _3). , S ₄ ). The outputs S _{1 to} S ₄ may be supplied to the control device 100 as they are, or each of them is provided with a signal converter 98 to be converted into a signal (for example, DC voltage) that can be handled easily by the control device 100. 100 may be supplied.

The control device 100 controls the high-frequency power output from each high-frequency power supply 60 so that the outputs S _{1 to} S ₄ from each electric field sensor 94 (or signals obtained by converting them) are substantially equal to each other. . For example, if the output from the electric field sensor 94 is smaller than the others, the high frequency power supplied to the antenna 28 provided with the electric field sensor 94 is increased, and the output from the electric field sensor 94 is substantially equal to the others. To be. The same applies to the reverse case.

  By the above control, for example, even if there is a difference in impedance due to a difference in temperature rise of the high-frequency electrode 30 constituting each antenna 28, a difference in impedance in a high-frequency power supply circuit to each antenna 28, etc., each antenna 28 is generated. Since the strength of the applied electric field can be made uniform, the uniformity of plasma in the parallel direction Y of the plurality of antennas 28 can be improved.

  Moreover, the above control can be performed in real time during the generation of the plasma 50.

  As a result, according to the plasma processing apparatus of this embodiment, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the plasma can also be achieved in the parallel direction Y of the plurality of antennas 28. Therefore, it is possible to improve the uniformity of the substrate processing, so that both effects can be combined and the two-dimensional processing in the substrate plane can be performed without increasing the distance between the antenna 28 and the substrate 2. Uniformity can be improved.

  Each antenna 28 is provided with a plurality of electric field sensors 94, and outputs (for example, average values) obtained by synthesizing outputs from the plurality of electric field sensors 94 of each antenna 28 are given to the control device 100, respectively. You may make it control the high frequency electric power output from each high frequency power supply 60 so that the said synthesized value may become substantially equal about each antenna 28, respectively.

  Each antenna 28 is provided with both the magnetic sensor 90 and the electric field sensor 94 as described above, and the outputs from both are synthesized (for example, weighted by the contribution ratio of the magnetic field and the electric field to the plasma generation). May be provided to the control device 100 to control the high-frequency power output from each high-frequency power source 60 so that the combined value is substantially equal for each antenna 28.

  Instead of providing a high frequency power supply 60 for each antenna 28 as in the embodiment shown in FIG. 16, a common high frequency power supply 60 and a distribution circuit 102 may be provided as in the embodiment shown in FIG. The embodiment of FIG. 21 will be described below mainly with respect to the differences from the embodiment shown in FIG. Since the magnetic sensor 90 and the electric field sensor 94 are as described above, redundant description is omitted.

  The plasma processing apparatus shown in FIG. 21 is provided between a high-frequency power source 60 for supplying high-frequency power to each antenna 28, and the high-frequency power source 60 and each antenna 28. A distribution circuit 102 that distributes power to each antenna 28 and that can vary the magnitude of high-frequency power distributed to each antenna 28 in response to an external control signal, and a plurality of magnetic sensors 90 as described above. In response to the outputs from the plurality of magnetic sensors 90, the control device 100 controls the magnitude of the high-frequency power distributed to each antenna 28 by the distribution circuit 102 so that the outputs are substantially equal to each other. And. The entire output of the high frequency power supply 60 may also be controlled by the control device 100.

  For example, the distribution circuit 102 may be inserted between the high-frequency power supply 60 and each antenna 28 and may have a plurality of variable impedances whose impedances are variable in response to control signals from the control device 100. . By controlling the variable impedance, the magnitude of the high frequency power distributed to each antenna 28 can be controlled.

  According to this embodiment, in response to the outputs from the plurality of magnetic sensors 90, the distribution circuit 102 controls the magnitude of the high-frequency power distributed to each antenna 28 so that the outputs are substantially equal to each other. Even if there is a difference in impedance due to a difference in temperature of the high-frequency electrode 30 constituting each antenna 28, a difference in impedance in a high-frequency power supply circuit to each antenna 28, etc. Since the strength of the magnetic field generated by the antenna 28 can be made uniform, the uniformity of plasma in the parallel direction Y of the plurality of antennas 28 can be improved.

  As a result, according to the plasma processing apparatus of this embodiment, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the plasma can also be achieved in the parallel direction Y of the plurality of antennas 28. Therefore, it is possible to improve the uniformity of the substrate processing, so that both effects can be combined and the two-dimensional processing in the substrate plane can be performed without increasing the distance between the antenna 28 and the substrate 2. Uniformity can be improved.

  As in the case of the embodiment shown in FIG. 16, an electric field sensor 94 may be provided instead of the magnetic sensor 90. By doing so, in response to the output from the electric field sensor 94, the distribution circuit 102 can control the magnitude of the high-frequency power distributed to each antenna 28 so that the respective outputs are substantially equal to each other. Thus, for example, even if there is a difference in impedance due to a difference in temperature rise of the high-frequency electrode 30 constituting each antenna 28, a difference in impedance in a high-frequency power supply circuit to each antenna 28, etc., Since the strength of the generated electric field can be made uniform, the uniformity of the plasma in the parallel direction Y of the plurality of antennas 28 can be improved.

  As a result, the uniformity of the substrate processing in the longitudinal direction X of the antenna 28 can be improved as described above, and the uniformity of the substrate processing can be improved by improving the uniformity of the plasma also in the parallel direction Y of the plurality of antennas 28. Therefore, even if the distance between the antenna 28 and the substrate 2 is not intentionally increased, it is possible to improve the processing uniformity in two dimensions within the substrate surface.

  Each antenna 28 is provided with both the magnetic sensor 90 and the electric field sensor 94 as described above, and the outputs from both are synthesized (for example, weighted by the contribution ratio of the magnetic field and the electric field to the plasma generation). May be supplied to the control device 100 to control the high-frequency power distributed to each antenna 28 by the distribution circuit 102 so that the combined value is substantially equal for each antenna 28.

2 Substrate 4 Vacuum container 24 Gas 28 Antenna 30 High frequency electrode 31, 32 Electrode conductor 33 Conductor 34 Gap 37 Opening 40 Dielectric case 42 Cooling pipe 43 Refrigerant passage 50 Plasma 60 High frequency power supply 90 Magnetic sensor 94 Electric field sensor 100 Control device 102 Distribution circuit I _R frequency current

Claims (9)

An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode is formed by arranging two electrode conductors, both of which are in a rectangular plate shape, parallel to each other with a gap therebetween so as to form a rectangular plate shape as a whole, and in the longitudinal direction of both electrode conductors. It has a reciprocating conductor structure in which one end is connected by a conductor, and the high-frequency current flows through the two electrode conductors in directions opposite to each other, and the gap between the two electrode conductors Each of the notches facing each other with a gap is provided, and an opening is formed by the facing notches, and a plurality of the openings are distributed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
Further, the antenna has two high-frequency electrodes, and between the two high-frequency electrodes, the both high-frequency electrodes are cooled and a cooling pipe through which a cooling medium flows is sandwiched. It has a structure housed in the dielectric case,
The distance between the outer main surface of each high-frequency electrode and the outer surface of the dielectric case opposite to the main surface is substantially equal to each other for the two high-frequency electrodes. Processing equipment. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode is formed by arranging two electrode conductors, both of which are in a rectangular plate shape, parallel to each other with a gap therebetween so as to form a rectangular plate shape as a whole, and in the longitudinal direction of both electrode conductors. It has a reciprocating conductor structure in which one end is connected by a conductor, and the high-frequency current flows through the two electrode conductors in directions opposite to each other, and the gap between the two electrode conductors Each of the notches facing each other with a gap is provided, and an opening is formed by the facing notches, and a plurality of the openings are distributed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
Further, the antenna has two high-frequency electrodes, and is attached to one main surface of each high-frequency electrode with a cooling pipe for cooling the high-frequency electrode through which a cooling medium flows, and It has a structure in which two high-frequency electrodes are housed in the dielectric case in a direction in which the cooling pipe is located inside,
The distance between the outer main surface of each high-frequency electrode and the outer surface of the dielectric case opposite to the main surface is substantially equal to each other for the two high-frequency electrodes. Processing equipment. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode is formed by arranging two electrode conductors, both of which are in a rectangular plate shape, parallel to each other with a gap therebetween so as to form a rectangular plate shape as a whole, and in the longitudinal direction of both electrode conductors. It has a reciprocating conductor structure in which one end is connected by a conductor, and the high-frequency current flows through the two electrode conductors in directions opposite to each other, and the gap between the two electrode conductors Each of the notches facing each other with a gap is provided, and an opening is formed by the facing notches, and a plurality of the openings are distributed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
Further, the antenna has a structure in which cooling pipes for cooling the high-frequency electrode and through which a cooling medium flows are attached to both main surfaces of the high-frequency electrode.
And the distance between both the main surfaces of the said high frequency electrode and the outer surface of the said dielectric case facing it is mutually made substantially equal, The plasma processing apparatus characterized by the above-mentioned. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode is formed by arranging two electrode conductors, both of which are in a rectangular plate shape, parallel to each other with a gap therebetween so as to form a rectangular plate shape as a whole, and in the longitudinal direction of both electrode conductors. It has a reciprocating conductor structure in which one end is connected by a conductor, and the high-frequency current flows through the two electrode conductors in directions opposite to each other, and the gap between the two electrode conductors Each of the notches facing each other with a gap is provided, and an opening is formed by the facing notches, and a plurality of the openings are distributed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
Furthermore, the high-frequency electrode has a refrigerant passage through which a cooling medium for cooling the high-frequency electrode flows.
And the distance between both the main surfaces of the said high frequency electrode and the outer surface of the said dielectric case facing it is mutually made substantially equal, The plasma processing apparatus characterized by the above-mentioned. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode has two electrode conductors arranged in parallel with a gap therebetween so as to form a rectangular plate shape as a whole, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. A reciprocating conductor structure is provided, in which the high-frequency current flows through the two electrode conductors in opposite directions, and further, a notch facing the gap side of the two electrode conductors across the gap. Each of which is provided with an opening formed by the opposed notch, and a plurality of the openings are disposed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
Further, the two electrode conductors constituting the high-frequency electrode are a pair of electrode conductors each bent in a U-shaped cross section, the two sides opposite to the bent portion of one of the electrode conductors, and the other The two sides opposite to the bent portion of the electrode conductor are arranged so as to face each other with the gap therebetween, and the opening is formed by providing the notch on each side. ,
The antenna has a structure in which a cooling pipe that cools the high-frequency electrode and in which a cooling medium flows is sandwiched between the bent electrode conductors and stored in the dielectric case. And
The plasma processing apparatus is characterized in that the distance between the two main surfaces outside the high-frequency electrode and the outer surface of the dielectric case facing each other is substantially equal to each other. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode has two electrode conductors arranged in parallel with a gap therebetween so as to form a rectangular plate shape as a whole, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. The reciprocating conductor structure has a structure in which the high-frequency current flows through the two electrode conductors in opposite directions, and further, a notch facing the gap side of the two electrode conductors across the gap. Each of which is provided with an opening formed by the opposed notch, and a plurality of the openings are disposed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
And the antenna has a substantially straight planar shape, a plurality of the antennas are arranged in parallel along the surface of the substrate,
A plurality of high frequency power supplies for supplying high frequency power to the antennas;
A plurality of magnetic sensors that are provided at substantially the same location for each of the antennas and detect the strength of the magnetic field generated by each of the antennas;
And a control device that controls high-frequency power output from each of the high-frequency power sources so that the outputs are substantially equal to each other in response to outputs from the plurality of magnetic sensors. Plasma processing equipment. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode has two electrode conductors arranged in parallel with a gap therebetween so as to form a rectangular plate shape as a whole, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. A reciprocating conductor structure is provided, in which the high-frequency current flows through the two electrode conductors in opposite directions, and further, a notch facing the gap side of the two electrode conductors across the gap. Each of which is provided with an opening formed by the opposed notch, and a plurality of the openings are disposed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
And the antenna has a substantially straight planar shape, a plurality of the antennas are arranged in parallel along the surface of the substrate,
A plurality of high frequency power supplies for supplying high frequency power to the antennas;
A plurality of electric field sensors that are provided at substantially the same location for each of the antennas and detect the strength of the electric field generated by each of the antennas;
And a control device that controls high-frequency power output from each of the high-frequency power sources so that the outputs are substantially equal to each other in response to outputs from the plurality of electric field sensors, Plasma processing equipment. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode has two electrode conductors arranged in parallel with a gap therebetween so as to form a rectangular plate shape as a whole, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. A reciprocating conductor structure is provided, in which the high-frequency current flows through the two electrode conductors in opposite directions, and further, a notch facing the gap side of the two electrode conductors across the gap. Each of which is provided with an opening formed by the opposed notch, and a plurality of the openings are disposed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
And the antenna has a substantially straight planar shape, a plurality of the antennas are arranged in parallel along the surface of the substrate,
Furthermore, a high frequency power source for supplying high frequency power to each antenna,
Provided between the high-frequency power source and the antennas, and distributes the high-frequency power output from the high-frequency power source to the antennas. The antennas respond to an external control signal. A distribution circuit in which the magnitude of the high-frequency power distributed to is variable,
A plurality of magnetic sensors that are provided at substantially the same location for each of the antennas and detect the strength of the magnetic field generated by each of the antennas;
A control device for controlling the magnitude of the high-frequency power distributed to the antennas by the distribution circuit so that the outputs are substantially equal to each other in response to outputs from the plurality of magnetic sensors. A plasma processing apparatus. An inductively coupled plasma processing apparatus that generates a plasma by generating an induction electric field in a vacuum vessel by flowing a high-frequency current through an antenna, and processes the substrate using the plasma,
The antenna has a structure in which a high-frequency electrode is housed in a dielectric case,
The high-frequency electrode has two electrode conductors arranged in parallel with a gap therebetween so as to form a rectangular plate shape as a whole, and one end in the longitudinal direction of both electrode conductors is connected by a conductor. A reciprocating conductor structure is provided, in which the high-frequency current flows through the two electrode conductors in opposite directions, and further, a notch facing the gap side of the two electrode conductors across the gap. Each of which is provided with an opening formed by the opposed notch, and a plurality of the openings are disposed in the longitudinal direction of the high-frequency electrode.
And the antenna is disposed in the vacuum vessel in a direction in which the main surface of the high-frequency electrode and the surface of the substrate constituting the antenna are substantially perpendicular to each other,
And the antenna has a substantially straight planar shape, a plurality of the antennas are arranged in parallel along the surface of the substrate,
Furthermore, a high frequency power source for supplying high frequency power to each antenna,
Provided between the high-frequency power source and the antennas, and distributes the high-frequency power output from the high-frequency power source to the antennas. The antennas respond to an external control signal. A distribution circuit in which the magnitude of the high-frequency power distributed to is variable,
A plurality of electric field sensors that are provided at substantially the same location for each of the antennas and detect the strength of the electric field generated by each of the antennas;
A controller for controlling the magnitude of the high-frequency power distributed to each antenna by the distribution circuit so that the outputs are substantially equal to each other in response to outputs from the plurality of electric field sensors. A plasma processing apparatus.

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