JP5853487B2 - Discharge electrode and discharge method - Google Patents

Description

  The present invention relates to a plasma discharge electrode and a plasma discharge method for performing plasma discharge in a vacuum.

  Plasma discharge is a discharge form that generates gas ionization by applying a voltage between a positive electrode and a negative electrode in a low vacuum atmosphere, and is used in various forms such as sputtering, plasma CVD, and plastic substrate surface treatment. . Sputtering is a method in which plasma cations collide with a target installed on a negative electrode called a cathode, and the particles sputtered by the collision adhere to the substrate to form a thin film. It is widely used in the film formation process. However, the conventional sputtering method has a disadvantage that the thin film formation rate is slower than the vacuum evaporation method or the like. For this reason, a magnetron sputtering method has been devised that uses a permanent magnet or an electromagnet as a magnetic circuit to form a magnetic field in the vicinity of the target, improving the speed of thin film formation and forming a thin film by sputtering in the manufacturing process of semiconductor parts and electronic parts. Enabled mass production. However, in a normal magnetron sputtering apparatus, only the lower magnet of the target is installed on the lower surface side of the target, and the magnetic field exposed to the target surface is used. Therefore, the magnetic field is formed in an arc shape in the vertical direction on the target surface and contributes to sputtering. A large deviation occurs in the parallel magnetic field distribution. Due to this bias of the parallel magnetic field distribution, the bias of the target erosion cannot be avoided, and the target utilization efficiency is limited. For example, Patent Document 6 and Non-Patent Document 2 describe that in a normal flat-plate-type magnetron electrode, the target utilization efficiency is limited to 20 to 30% (or usually 25%) due to the bias of erosion. Rotating target method is adopted for the improvement. Non-Patent Document 1 describes a technique for rotating a magnet itself in order to improve normal target utilization efficiency (20 to 40%). Further, Non-Patent Document 3 describes that the target utilization efficiency is reduced to 12% in the Ni target that is a magnetic material, and the target is utilized by rotating the magnet as in Non-Patent Document 1 for the improvement. The efficiency is improved. That is, in the conventional magnetron sputtering, there is a problem that if the target is moved or the magnet is not moved, the target utilization efficiency is not increased and the target cost is increased. On the other hand, when the plasma discharge is applied to a CVD apparatus, the problem is the same. The confinement region of the high-density plasma indicated by the parallel magnetic field distribution is biased, which hinders efficient gas decomposition and polymerization. It was. Therefore, there are approaches such as Patent Document 1, Patent Document 2, and Patent Document 3 in which a magnet is arranged on the side surface and the upper surface of the target to improve the magnetic circuit to enhance the parallel magnetic field on the target surface. . In the above publication, the target lower magnet and the target upper magnet have the same polarity, and the parallel magnetic field on the target is increased by the repulsion of both magnetic fields. Patent Document 4 also uses a target material as a part of the yoke, arranges magnets on the target surface or side surfaces, and strengthens the parallel magnetic field on the target surface.

  Further, in Patent Document 5, an effort is made to strengthen the parallel magnetic field formed on the target surface by installing a magnetic part described as an auxiliary target on the side surface of the target and attracting / releasing the magnetic field lines on the back side of the target.

JP 61-124567 A JP 7-228971 A JP-A-8-176817 Japanese Patent Publication No.59-52957 JP 2005-509091 A WO2009-005068

VACUUM84 P1372 to P1376 published by ELSEVIER 2010, “Completely Flat erosion magnetron sputtering using a rotating asymmetrical yoke magnet” ELSEVIER 2009 Publication VACUUM83 P518 to P521, “New target materials for innovative applications on glass” VACUUM83 P470 to P474 published by ELSEVIER 2009 “Wide erosion nickel magnetron sputtering using an eccentrically Rotating center magnet”

  However, in the configurations of Patent Document 1, Patent Document 2, and Patent Document 4 in which magnets are directly arranged on the side surface and the surface of the target, there is a problem in stably using the magnets, and the thin film formation speed is not sufficiently improved.

  For example, FIG. 11 shows a case where sputtering is performed with the configuration of Patent Document 1. The magnetic field lines 84 between the target lower magnets 82 are absorbed inside the target 80 which is a magnetic body, and magnetron sputtering is performed by the action of the magnetic field lines 83 between the target upper magnets 81. However, the positive ions 85 collide with the target 80, eject target particles 86 as a target material, and also collide with the target upper magnet 81. Due to the collision impact of the positive ions 85, the target upper magnet 81 rapidly becomes a high temperature state. As a result, the magnet itself exceeds the Curie point and demagnetizes, so the function as magnetron sputtering cannot be obtained sufficiently, or the input power must be lowered to reduce the film formation speed to prevent high temperature It becomes. Therefore, the configuration in which the target upper magnet 81 serving as the magnetic field generating unit is directly installed on the side edge of the surface of the target 80 serving as the plasma generation region cannot exhibit a good sputtering function.

  Similarly, Patent Document 2 has the same problem as Patent Document 1. Furthermore, since the adjacent magnets are determined to have opposite polarities, the sputtering mechanism itself is different from the present invention.

  On the other hand, Patent Document 4 has a configuration in which a magnet cover is installed so that the magnet installed on the upper part of the target is not sputtered. However, the magnet cover eventually generates heat due to the impact of a cation, and heat transfer from the magnet cover causes the magnet to become hot. Therefore, the magnet is demagnetized similarly to Patent Document 1, and the sputtering function cannot be obtained.

  On the other hand, in Patent Document 3, as shown in FIG. 12, a cooling shield 92 that is insulated in a non-contact manner is installed between the target 90 and the target upper magnets 93 and 94, and the target upper magnets 93 and 94 are moved away from the target 90. It is carried out. Further, similarly to the configuration of Patent Document 1, target lower magnets 95 and 96 are also provided. However, in this configuration, although the magnet can be protected, the magnetic field lines 98 emitted from the target upper magnets 93 and 94 are attenuated as they approach the center of the target because they are separated from the target 90, and the target width cannot be increased. is there. Furthermore, as shown in FIG. 13, when the target is the magnetic target 110, most of the magnetic force lines 111 are absorbed from the end surface of the target, and it becomes difficult to form a uniform magnetic field on the target surface. In other words, if a magnet that is a magnetic field emission component is placed near the target, it is advantageous for forming a parallel magnetic field on the target surface, but the magnet itself will be damaged, and if it is far from the target to protect the magnet, the magnetic field can be sufficiently formed. There was a problem that the effect could not be obtained.

  On the other hand, Patent Document 5 shown in FIG. 14 is the same in that the magnetic force lines 125 are guided to the surface of the target 120 using the magnetic bodies 121 and 122 (auxiliary target in this publication), but according to the knowledge of the present inventors. For example, the mechanism is fundamentally different from the present invention in that the target lower magnet 123 is arranged and no magnet is provided on the target surface side. Further, in the configuration of Patent Document 5, magnet damage does not occur, but when the target 120 is a magnetic target, the target lower magnet 123 is brought close to the target back side magnet in order to attract and guide the target magnetic field to the target surface side. Therefore, it is necessary to arrange the magnetic bodies 121 and 122 at the target side surface positions as shown in FIG. For example, when the magnetic bodies 131 and 132 are arranged on the surface of the target 130 as shown in FIG. 15, the magnetic lines 133 are almost absorbed in the target 130 that is a magnetic body, and the installation of the magnetic bodies 131 and 132 is the target surface. This is because it is no longer effective in improving the parallel magnetic field. That is, since Patent Document 5 is characterized in that the magnetic bodies 131 and 132 are installed on the side surface of the target, the mechanism is different from that of the present invention characterized in that the magnetic body is arranged on both upper side edges of the target. Further, even if the configuration of Patent Document 5 shown in FIG. 14 is used, not all the magnetic force lines 125 generated from the target back surface side magnet 123 are directed to the magnetic body, and most of them are absorbed into the target 120 which is a magnetic body. The strength of the parallel magnetic field formed on the target surface is not sufficient and the degree of improvement is limited.

  The present invention solves the above-mentioned problems and forms a uniform parallel magnetic field distribution on the target regardless of whether the target is a magnetic body or a non-magnetic body, thereby obtaining uniform erosion and improving target utilization efficiency. Another object of the present invention is to provide a plasma discharge electrode and a discharge method capable of improving the sputter thin film formation rate or the CVD film formation rate.

  In order to achieve the above object, according to the present invention, in a discharge electrode having a flat plate target, a magnetic body provided along both side edges on the surface side of the flat plate target and facing the flat plate target, A discharge electrode is provided which is provided in combination with the magnetic body on the opposite side of the flat plate target with the magnetic material therebetween, and has a target upper magnet having a different polarity relationship with respect to the flat plate target.

  Moreover, according to the preferable form of this invention, the discharge electrode which the lower surface of the said magnetic body is substantially the same as the surface of the said flat plate target, or upper direction is provided.

  Further, according to a preferred embodiment of the present invention, in the cross section perpendicular to the longitudinal direction of the flat plate target, the facing surfaces between the magnetic bodies are inclined outward at an angle θ with respect to the normal direction of the flat plate target surface, A discharge electrode in which θ is in the range of 0 ° <θ ≦ 45 ° is provided.

  According to a preferred embodiment of the present invention, the target has a lower magnet on the back surface side of the flat target, which is the position facing the magnetic body across the flat target in the thickness direction of the flat target, A discharge electrode is provided in which the direction of the magnetic force line emission of the lower magnet is the thickness direction of the flat target, and the magnetic poles of the magnetic body and the target lower magnet have the same polarity.

  Moreover, according to the preferable form of this invention, the discharge electrode in which the surface side magnetic field and back surface side magnetic field of the said flat plate target form a loop is provided.

  Moreover, according to the preferable form of this invention, the said magnetic body, the said target upper magnet, and the said target lower magnet provide the discharge electrode which has a temperature control means.

  Moreover, according to the preferable form of this invention, the discharge electrode whose said flat plate target is a magnetic material which has Fe, Co, or Ni as a main component is provided.

  According to another aspect of the present invention, there is provided a discharge method for generating discharge using a magnetic field formed on a surface of a flat plate target, which is provided along both side edges on the surface side of the flat plate target, A magnetic material facing the flat plate target, a target upper magnet provided in combination with the magnetic material on the opposite side of the flat plate target, and the flat plate target in the thickness direction of the flat plate target A target lower magnet at the back surface side position of the flat plate target, which is a position facing the magnetic body, the opposing magnetic poles of the target upper magnets are of different polarity, and the targets facing each other across the target thickness direction By making the magnetic poles of the upper magnet and the target lower magnet the same polarity, a substantially parallel magnetic field is formed between the magnetic bodies on the target surface. And charge removal method for generating discharge by using the magnetic field is provided.

  Also, according to a preferred embodiment of the present invention, the parallel magnetic flux density in the magnetic field forming region defined by 2H with respect to the width H of the magnetic body is ± 0.35 W from the center of the width W between the magnetic bodies. The distribution is formed within Bc ± 20% with reference to the parallel magnetic flux density Bc at an arbitrary height h in the range of 0 to 2H in the height direction and the center in the width direction, and the parallel magnetic flux is used. There is provided a static elimination method for generating discharge.

  Moreover, according to the preferable form of this invention, the static elimination method whose said parallel magnetic flux density Bc is the range of 10 mT to 500 mT is provided.

  Moreover, according to the preferable form of this invention, the sputtering device which has the said discharge electrode as a sputtering source is provided.

  According to a preferred embodiment of the present invention, there is provided a thin film forming method characterized in that a thin film is formed by introducing a gas into the sputtering apparatus and sputtering a target.

  Moreover, according to the preferable form of this invention, the CVD apparatus characterized by having the said discharge electrode as a source gas reaction source is provided.

  Moreover, according to the preferable form of this invention, the CVD apparatus whose said source gas is hydrocarbon gas, silicon compound gas, or fluorine compound gas is provided.

  According to a preferred embodiment of the present invention, there is provided a thin film forming method characterized in that a CVD thin film is formed by introducing hydrocarbon gas, silicon compound gas or fluorine compound gas as a source gas into the CVD apparatus. .

  According to the present invention, a uniform parallel magnetic field distribution is formed on the target regardless of whether the target is a magnetic body or a non-magnetic body, and uniform erosion can be obtained. It is possible to provide a discharge electrode and a discharge method capable of improving the thin film formation speed or the CVD film formation speed. Further, since no target or magnet moving mechanism is required, the effect can be obtained with a simple and inexpensive discharge electrode.

The single discharge cross-sectional schematic diagram of the discharge electrode by 1st embodiment concerning this invention. The single discharge cross-sectional schematic of the discharge electrode by 2nd embodiment concerning this invention. The single discharge cross-sectional schematic of the discharge electrode by 3rd embodiment concerning this invention. Schematic which shows the film-forming apparatus using the discharge electrode by 3rd embodiment. The graph which plotted the parallel magnetic flux density distribution on the target in the discharge electrode by 1st embodiment. The figure which plotted the parallel magnetic flux density distribution on the target in the discharge electrode by 2nd embodiment. The figure which plotted the parallel magnetic flux density distribution on the target in the discharge electrode by 3rd embodiment. The single discharge cross-sectional schematic by the discharge electrode form of the comparative example 1. FIG. The graph which plotted the parallel magnetic flux density distribution on a target in the discharge electrode of the comparative example 1. FIG. The graph which plotted the parallel magnetic flux density distribution on the target in the discharge electrode of the comparative example 2. FIG. The discharge cross-sectional schematic in the structure of a prior art (patent document 1). The discharge cross-sectional schematic diagram at the time of comprising with a nonmagnetic target by a prior art (patent document 3). The discharge cross-sectional schematic at the time of comprising with a magnetic body target by a prior art (patent document 3). The discharge cross-sectional schematic in the structure of a prior art (patent document 5). The discharge cross-sectional schematic diagram at the time of installing a magnetic body on a target in the structure of a prior art (patent document 5). The single discharge cross-sectional schematic of the discharge electrode in connection with embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. However, the components described in this embodiment are merely examples, and the technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments.

  FIG. 16 shows a cross section perpendicular to the longitudinal direction of the target 140 in the discharge electrode 205. In the discharge electrode 205 having the flat plate target 140 according to the present invention, magnetic bodies 143 and 151 which are provided along both side edges on the surface side of the flat plate target 140 and face each other with the flat plate target interposed therebetween, and the magnetic bodies 143, And the target magnets 141 and 152 which are provided in combination with the magnetic bodies 143 and 151 on the opposite side of the flat plate target 140 with the flat plate target 140 being spaced apart from each other. To do. The lower surfaces of the magnetic bodies 143 and 151 are preferably substantially the same as or above the surface of the flat plate target 140.

  Here, when the flat plate target 140 is a flat plate in a state where the discharge electrode 205 is viewed from above, it may be a rectangular parallelepiped, a donut shape, or an elliptical shape, and a shape matching the shape of the discharge electrode can be selected. In general, there are many oval shapes with the central part cut out. In addition, a single flat plate target shape necessary for the discharge electrode 205 may be formed, or a plurality of flat plate target shapes may be formed together. Moreover, thickness, surface roughness, etc. can also be selected arbitrarily.

  The target surface side is a discharge surface, and if the discharge electrode 205 is a sputter electrode, it indicates the target surface on the side where the flat plate target 140 is sputtered by the positive ions 144. The both side edges on the target surface side refer to two corners on the discharge surface side of the flat plate target 140 in FIG. 16 in which the discharge electrode 205 is seen in cross section, and the present invention is close to the two corners in the present invention. The magnetic bodies 143 and 151 are arranged. The cross-sectional shape of the magnetic material may be square, round or polygonal. The magnetic bodies 143 and 151 are provided so as to face each other across the flat plate target 140 and should be installed on the outside along the corners of the target. It is preferable that the magnetic bodies 143 and 151 do not run on the flat plate target. it can. In addition, it is acceptable to place the lower surface of the magnetic body somewhat below the surface of the flat plate target. Here, the lower surface of the magnetic body is a surface in the target thickness direction of the magnetic bodies 143 and 151 installed along the target corner. Target upper magnets 141 and 152 are provided on the opposite sides of the opposing magnetic bodies 143 and 151, respectively, and are attracted and combined with the magnetic bodies 143 and 151 by the lines of magnetic force emitted. The magnetic polarities of the target upper magnets 141 and 152 are different from each other on the surfaces facing the magnetic bodies 143 and 151 and the flat plate target 140, and if one is N pole, the other is set to S pole. Furthermore, in the present invention, it is preferable that the lower surface of the magnetic material is on the same line as or higher than the surface of the flat plate target. Upward refers to the direction (height direction) away from the flat plate target in the target thickness direction. In this configuration, the lines of magnetic force emitted from the target upper magnet 141 are absorbed from the anti-target surface of the magnetic body 143 and are emitted again from the opposing surface. The released magnetic force lines 146 are absorbed by the other magnetic body 151 facing the flat plate target 140, flow through the magnetic body 151, and absorbed by the other target upper magnet 152 on the counter-target side. Therefore, strong magnetic force lines 146 are formed substantially parallel to the target plane direction between the opposing magnetic bodies. By forming a strong parallel magnetic flux on the target surface in this way, the amount of electrons trapped in the parallel magnetic flux increases dramatically, so that a stable strong discharge can be obtained over a wide range on the flat plate target, and the efficiency of the magnetron discharge Will improve. Further, since the amount of the cation 144 colliding with the flat plate target is substantially uniform between the magnetic bodies 143 and 151 due to the above-described effect, the erosion progresses substantially parallel to the target thickness direction with respect to the flat plate target surface, and is localized. Erosion is eliminated, and target usage efficiency is dramatically improved. Further, it is preferable that the combined target upper magnet 141 has the same thickness as the magnetic body 143 or is slightly thinner in order to release all the magnetic field lines of the magnet from the magnetic body. Further, when the lower surface of the magnetic material is below the target surface, for example, when it is installed on the side surface of the flat plate target 140, most of the magnetic force lines emitted from the magnetic material pass through the inside of the flat plate target 140. As a result, the efficiency of the magnetron discharge cannot be improved sufficiently and the effect becomes insufficient. Therefore, it is preferable that the lower surface of the magnetic body is on the same line as or higher than the target surface.

  Further, in the present invention, in FIG. 16, the facing surface between the magnetic bodies 143 and 151 is inclined outward by an angle θ with respect to the normal direction of the surface of the flat plate target 140, and θ is in the range of 0 ° <θ ≦ 45 °. It is characterized by being.

  The angle θ described here is an angle at the intersection of the opposing surfaces of the magnetic bodies 143 and 151 that separate the flat plate target 140 and the normal direction (vertical direction) of the flat plate target 140 when the discharge electrode 205 is viewed from the cross-sectional direction. The angle obtained by subtracting the tip angle of the magnetic material facing surface from 90 ° is indicated. The angle θ may be 0 ° or more and less than 45 °, but 20 to 30 ° is particularly preferable. This is because the magnetic force lines 146 are emitted from the inclined surface of the magnetic body 143, so that the attenuation gradient toward the normal direction (vertical direction, upward) of the flat plate target is improved in the parallel magnetic flux distribution on the target. Specifically, the uniformity of the parallel magnetic flux density between the magnetic bodies 143 and 151 is as good as that of the magnetic body without inclination, and further, the parallel magnetic flux density near the surface of the flat plate target 140 is maximized toward the normal direction. A gradient in which the parallel magnetic flux density gradually decreases is obtained. At this time, if the angle θ is 0 ° or more and less than 45 °, a parallel magnetic flux density region sufficient for magnetron discharge can be widened without decreasing the amount of attenuation of the parallel magnetic flux density rapidly even when moving away from the target in the normal direction. Can be maintained. In other words, due to the effect of adjusting the decay gradient of the parallel magnetic flux density in the normal direction of the area on the target, which is the area where the magnetron discharge is performed, the discharge state is more stable and better than that using a magnetic body without an inclination. Due to the effect of adjusting the parallel magnetic flux density in the normal direction, high power can be stably supplied, so that the sputtering rate is further improved and the target utilization efficiency is also improved. Further, the amount of the sputtered particles 145 flying from the target due to the tilting effect colliding with the surface facing the magnetic material is significantly reduced, so that the sputter rate is also improved. In addition, when sputtered particles accumulate on the surface facing the magnetic material, arc discharge tends to occur, but this problem can also be avoided.

  Furthermore, in the present invention, target lower magnets 142 and 153 are arranged at the target back side positions facing the magnetic bodies 143 and 151 with a target thickness in the target thickness direction, and the magnetic force lines of the target lower magnets 142 and 153 are released. The direction is the target thickness direction, and the magnetic poles of the magnetic body 143 and the target lower magnet 142 or the magnetic body 151 and the target lower magnet 153 facing each other across the target thickness are the same polarity.

  This configuration shows a more favorable effect when the flat plate target 140 is a magnetic material mainly composed of Fe, Co, or Ni, but can also be applied to a non-magnetic target. The target back surface side refers to the back surface with respect to the front surface side which is the discharge surface, and does not limit the range to the inside of the target width. The entire range on the same line as the target back surface or on the opposite side from the back surface (downward) Pointing. The target lower magnets 142 and 153 arranged at the target back side position have the same polarity as the magnetic bodies 143 and 151 facing each other across the target thickness direction, and the magnetic force line emission surfaces thereof are facing the facing magnetic body 143 (target thickness direction). To turn to. The magnetic field line emission surface of the target lower magnet 142 is preferably a position directly below the magnetic field line emission surface of the magnetic body 143, but there is no problem as long as it faces the magnetic body 143. With this configuration, the lower magnets of the target have different polarities, and the magnetic lines of force 147 flow into the space between the magnets and the target to form a magnetic field. In particular, FIG. 16 shows the case of a magnetic target, and many magnetic field lines 147 are absorbed into the target. Since the magnetic field lines 147 have the same polarity (same direction) as the magnetic field lines 146 on the target surface side, a repulsive force is generated between the magnetic fields, and an effect of pushing up the magnetic field lines on the target surface side is produced. Normally, in the case of a magnetic target, even if the magnetic body 143 is provided along both side edges on the target surface side, the magnetic field lines 146 emitted from the magnetic body 143 are slightly absorbed by the flat plate target 140, and the parallel magnetic flux density on the target surface. The whole tends to go down. However, when this configuration is used, a strong parallel magnetic flux can be formed on the target surface even in the magnetic target due to the repulsion effect, and a magnetron discharge can be stably formed. Conventionally, it has been known that the use efficiency of a target is deteriorated in a magnetic target, but if this configuration is used, it becomes possible to dramatically increase the use efficiency of the target. The magnetic field lines 147 that have flowed through the flat plate target 140 are absorbed by the target lower magnet 153 in the vicinity of the other end face.

  Further, the present invention is characterized in that in the configuration having the target lower magnets 142 and 153, the target surface side magnetic field and the target back surface side magnetic field each form a loop. The magnetic field loop described here means that the lines of magnetic force emitted from one magnet are absorbed by the other magnet, and magnetically move from the opposite polarity side of the other magnet to the opposite polarity side of the first magnet via the yoke member. This means that the flow of magnetic field lines that are connected converges in a loop shape, not an open shape.

  Specifically, the magnetic lines of force emitted from the target upper magnet 141 flow through the magnetic body 143 and are formed as magnetic lines of force 146 on the surface side of the flat plate target 140, and then flow through the magnetic body 151 to the target upper magnet 152. Absorbed. However, it is characterized in that a so-called magnetic field loop configuration is formed in which the flow of magnetic lines of force is not formed, but flows through the inside of the yoke 148 from the target upper magnet 152 and returns to the target upper magnet 141 again. Although the above shows the flow of a magnetic field surrounding the target, the same applies to the magnetic field installed on the lower surface of the flat plate target 140. That is, the magnetic lines of force released from the target lower magnet 142 flow into the flat plate target 140 in the state of the magnetic lines of force 147 and are absorbed by the target lower magnet 153, but further flow through the yoke 149 from the target lower magnet 153, and again below the target lower part. It is characterized in that a magnetic field loop returning to the magnet 142 is formed. That is, a double magnetic field loop having a magnetic field loop with a small target back surface magnetic field is formed inside a magnetic field loop with a large target surface magnetic field. By forming a double magnetic field loop as described above, it is possible to efficiently form a stronger magnetic field on the target surface without forming a leakage magnetic field at the end portion at an unnecessary position.

Further, the present invention is characterized in that the magnetic body, the target upper magnet and the target lower magnet have temperature control means.
The members in contact with the discharge region near the surface of the flat target 140 are all heated by the impact of the cations 144. However, when the magnetic bodies 143 and 151 are heated to a high temperature, the target upper magnets 141 and 152 are also heated due to heat conduction. The magnet will be demagnetized and damaged beyond the Curie point. In order to avoid this, the temperature of the magnetic body or magnet is controlled. As the temperature control method, it is simple and preferable to control the temperature by passing cooling water, but the refrigerant may be oil or a gas refrigerant instead of water, or a contact cooling method such as a Peltier element. FIG. 16 shows that the cooling water 150 is passed through the magnetic body 143 to control the temperature of the magnetic body 143 and the target upper magnet 141. The target lower magnets 142 and 153 are preferably installed in a cooling water tank (not shown).
[First embodiment]
Next, details of the first embodiment will be described.

  FIG. 1 shows a schematic diagram of a single discharge cross section of a discharge electrode according to the first embodiment. In the cathode 1 of the discharge electrode 200, 10 is a target whose material is selected depending on the film to be generated, and magnetic bodies 11 a and 11 b are provided across the target 10 along both side edges on the surface side of the target 10. The lower surfaces of the magnetic bodies 11a and 11b are installed at substantially the same position as the surface of the target 10 or at an upper position. Further, target upper magnets 12a and 12b are combined with the opposite surfaces of the magnetic bodies 11a and 11b to the target 10, respectively, and the target upper magnets 12a and 12b are opposed to each other with opposite polarity across the magnetic bodies 11a and 11b and the target 10. doing. The target 10 is pressed against the backing plate 22 by the target presser 20 and the screw 21, and both the backing plate 22 and the target presser 20 are fixed to the water cooling case 23 by the screw 21. Cooling water 24 whose temperature is controlled circulates inside the water cooling case 23, and the target 10 is cooled via the backing plate 22. An O-ring 25 is installed on the contact surface between the backing plate 22 and the water cooling case 23 to seal the cooling water 24.

  On the other hand, a yoke part 13 made of a magnetic material, an auxiliary magnet 14, a yoke part 15, and a yoke plate 16 are contact-connected to the opposite target surfaces of the target upper magnets 12a and 12b, and the target upper magnets 12a and 12b are magnetically joined. Let Therefore, the target upper magnets 12 a and 12 b form a magnetic field loop on the outer periphery of the target 10 and the water cooling case 23 through the above-described components. The magnetic field loop in the present invention refers to the flow of a magnetic field that converges in an annular shape. That is, in FIG. 1, the magnetic field lines 28 are emitted from the north pole of the target upper magnet 12a through the magnetic body 11a, cross over the target substantially in parallel, and absorbed by the magnetic body 11b installed on the other side edge of the target surface. And is absorbed by the south pole of the other target upper magnet 12b combined with the magnetic body 11b. The N-pole magnetic field lines of the target upper magnet 12b flow through the members of the yoke part 13, the auxiliary magnet 14, the yoke part 15, and the yoke plate 16, and are absorbed again into the south pole of the target upper magnet 12a to terminate the magnetic flux loop. That is, in the present invention, the magnetic bodies 11 a and 11 b are installed on both side edges of the surface of the target 10, and a magnetic field flow is formed so as to surround the target 10 in an annular shape, thereby forming a strong and uniform parallel magnetic flux region on the target 10. It can be formed. In particular, the distribution of the parallel magnetic flux density in the magnetic field forming region defined by 2H with respect to the center C of the opposing distance W between the magnetic bodies 11a and 11b and 2H with respect to the height H of the magnetic bodies 11a and 11b, It is characterized in that it can be made uniform within Bc ± 20% with reference to the parallel magnetic flux density Bc at an arbitrary height h position in the range of 0 to 2H in the height direction and the center position in the width direction. At this time, the parallel magnetic flux density Bc is set in the range of 10 mT to 500 mT. Electrons are trapped in the strong parallel magnetic flux region on the target 10 to generate magnetron discharge, the discharge state of magnetron sputtering is stabilized, and high power can be input, so that the sputtering rate is improved. Moreover, since a uniform parallel magnetic flux area | region can be formed on the target 10, the utilization efficiency of the target 10 improves dramatically. On the other hand, when the lower surfaces of the magnetic bodies 11 a and 11 b are below the target surface (when they are on the target side surface), part or most of the N-pole magnetic field lines emitted from the magnetic body 11 a pass through the inside of the target 10. Thus, the parallel magnetic flux to be formed on the surface of the target 10 is reduced by being absorbed by the magnetic body 11b. This state becomes particularly prominent when the material of the target 10 is a magnetic material. As a result, the discharge state of magnetron sputtering becomes extremely unstable, or only low power can be input, and only a low sputtering rate can be obtained, and target utilization efficiency is also reduced. That is, when the magnetic bodies 11 a and 11 b are located on both side edges on the surface side of the target 10, the above effect can be obtained. Even when the magnetic flux loop is not formed, the parallel magnetic flux to be formed on the surface of the target 10 is reduced, resulting in unstable discharge, low sputter rate, and low target utilization efficiency. Cooling water 19 circulates inside the magnetic bodies 11a and 11b, and temperature control is performed so that the magnetic bodies 11a and 11b do not reach a high temperature even when they are struck by cations. In other words, in order to increase the efficiency of magnetron sputtering, it is possible to emit strong magnetic lines of force from both edges of the surface of the target 10, and the magnetic field line emitting component is used as the target upper magnet 12 a. By using the temperature-controlled magnetic bodies 11a and 11b instead of 12b, the magnet ability is prevented from being damaged due to a high temperature, and magnetron discharge by stable magnetic field line emission becomes possible.

Next, details of the constituent members will be described. The target 10 is preferably a non-magnetic material such as copper, but a magnetic material can also be applied. The thickness of the target can be arbitrarily selected from about 1 mm to about 30 mm, and the target width W2 can be arbitrarily selected from about 10 mm to about 100 mm. There is no problem as long as the material of the magnetic bodies 11a and 11b is a magnetic body, but SUS430, nickel or the like having corrosion resistance is preferable. When the target 10 is a magnetic material, it is preferable to use the same material. In FIG. 1, the shapes of the magnetic bodies 11a and 11b are rectangular, but they may be polygonal or round. It is desirable from the viewpoint of target utilization efficiency that the facing distance W between the magnetic bodies 11a and 11b is set to be the same width as the target width W2 or slightly narrower. The target upper magnets 12a and 12b are preferably those having high magnetic strength, such as neodymium magnets, samarium cobalt magnets, and alnico magnets. However, a magnet with a low magnetic force such as a ferrite magnet can be used even though the sputtering rate is lowered. The yoke parts 13 and 15 are preferably made of SUS430 or nickel, which is a magnetic material and has good corrosion resistance, and the auxiliary magnet 14 is also preferably a magnet having high magnetic strength, similar to the on-target magnets 12a and 12b. Unnecessary unintentional magnetic flux loops may be formed at the target upper magnets 12a and 12b and the auxiliary magnets 14 due to excessive magnet strength or problems with the yoke design, thereby causing unnecessary unintentional intentions. May induce a magnetron plasma discharge. In that case, it causes contamination due to sputtering of an unintended material, and power is consumed for unnecessary plasma discharge, so that the film formation efficiency is lowered, or a member that does not consider cooling is unnecessary. A component such as a magnet or a resin heated by plasma may be damaged by heat, or may become a starting point of abnormal discharge, and may cause various troubles. In order not to generate such an unnecessary unintended magnetron plasma discharge, a magnetic shield made of a magnetic material is provided so as to obscure a portion where an unnecessary unintended magnetic flux loop is formed, or unnecessary. It is preferable to provide an insulator cover on the surface of the electrode where unintended discharge occurs. Particularly around the magnet, it is more preferable to magnetically shield the vicinity of the target upper magnets 12a and 12b and the auxiliary magnet 14 because the magnet itself can easily form a magnetic flux loop. For example, the area around the magnet means the cover 17 and the cover 18 as shown in FIG. The same applies to other embodiments. The auxiliary magnet 14 is for deflecting and attracting the anti-target side magnetic field lines of the target upper magnets 12a and 12b. Therefore, the auxiliary magnet 14 may be a magnet with weak magnetic force such as a ferrite magnet, and may be a magnetic material instead of a magnet. The yoke plate 16 may be made of a magnetic material, but SUS430 or nickel is preferable. The target presser 20 and the backing plate 22 are preferably made of a non-magnetic material, and are preferably made of copper or the like having good thermal conductivity. The screw 21 is preferably a non-magnetic material such as SUS304 with good corrosion resistance. The water-cooled case 23 is preferably a non-magnetic material with high corrosion resistance, and SUS304 is preferred. In this configuration, the target 10 is brought into contact with the backing plate 22 and cooled by the target holder 20 and the screw 21, but the target 10 is directly joined to the backing plate 22 by bonding without using the target holder 20, or the backing plate 22. The target having the same width as that of the water cooling case 23 may be directly screwed to the water cooling case 23 without using. Further, a heat conduction auxiliary material such as a carbon sheet may be sandwiched between the interface between the target 10 and the backing plate 22. A cover 17 is installed on the upper surfaces of the target upper magnets 12a and 12b, and a cover 18 is also installed on the surface of the auxiliary magnet 14 facing away from the target. The covers 17 and 18 may be made of a non-magnetic material. However, if a magnetic material is used, there is a magnetic field shielding effect and the discharge is more stable. An anode 27 is formed around the cathode 1 so as to surround the cathode. It is assumed that the gap between the anode 27 and the cathode 10 is kept constant via a spacer 26 made of an insulating member. The cathode 1 is electrically insulated from the anode 27 by a spacer 26. The anode 27 is preferably made of SUS304 which is a non-magnetic material and has corrosion resistance, and its opening is preferably equal to or wider than the distance W between the magnetic bodies 11. Although not shown, it is more desirable to control the temperature of the anode 27 by joining a temperature-controlled cooling water pipe or the like.
[Second Embodiment]
FIG. 2 shows a schematic diagram of a single discharge cross section of a discharge electrode according to a second embodiment of the present invention. The component configuration of the discharge electrode 201 is the same as that of the first embodiment shown in FIG. 1, but the magnetic bodies that are provided and faced along both edges of the surface of the target 10 are the inclined magnetic bodies 30a and 30b. The opposing surface is inclined symmetrically at an angle θ. The angle θ described here is an angle at the intersection of the opposing surfaces of the magnetic bodies 30a and 30b that separate the flat plate target 10 and the normal direction (vertical direction) of the surface of the flat plate target 10 when the discharge electrode 201 is viewed from the cross-sectional direction. The angle obtained by subtracting the tip angle of the magnetic material facing surface from 90 ° is indicated. The angle θ may be 0 ° or more and less than 45 °, but 20 to 30 ° is particularly preferable. This is because the magnetic field lines 31 are emitted from the inclined surface of the magnetic body 30a, so that the attenuation gradient toward the normal direction (vertical direction, upward) of the flat plate target is improved in the parallel magnetic flux distribution on the target.
Specifically, the uniformity of the parallel magnetic flux density at the distance W between the magnetic bodies 30a and 30b is as good as in the first embodiment, and further, the parallel magnetic flux density near the surface of the target 10 is maximized and heads in the vertical direction. A gradient in which the parallel magnetic flux density gradually decreases is obtained. That is, the effect of adjusting the attenuation gradient of the parallel magnetic flux density in the vertical direction makes the discharge state more stable and better than in the first embodiment without disturbing the discharge due to the strength of the partial magnetic flux density in the vertical direction. . Due to the effect of adjusting the parallel magnetic flux density in the vertical direction, the target utilization efficiency is further improved as compared with the first embodiment. Further, the amount of sputtered particles flying from the target 10 colliding with the magnetic material facing surface due to the tilting effect of the tilted magnetic bodies 30a and 30b is greatly reduced, so the sputter rate is improved over the first embodiment. To do. Further, if the sputtered particle deposition on the magnetic material facing surface increases, arc discharge is likely to occur, but this problem can also be avoided. However, when the angle θ of the inclined magnetic bodies 30a and 30b is 45 ° or more, the distance between the magnetic force line emission surfaces (distance between the inclined surfaces) increases away from the target surface in the vertical direction. As a result, the amount of attenuation of the parallel magnetic flux density in the vertical direction increases and the parallel magnetic flux density above the target becomes too low, so that the area where the magnetron discharge can be formed is narrowed. As a result, only low power can be input, the sputtering rate is lowered, and the target utilization efficiency is also reduced.
[Third embodiment]
FIG. 3 shows a conceptual diagram of a discharge electrode according to the third embodiment of the present invention. In this configuration, a non-magnetic material may be used for the target 10, but a more favorable result is shown for magnetic materials such as Fe, Ni, and Co. The configuration in which magnetic lines of force are formed from the upper part of the target 10 in the cathode 1 of the discharge electrode 202 is the same as in the second embodiment, but the water cooling case 23 that is opposed to the gradient magnetic bodies 30a and 30b across the target thickness direction. It has target lower magnets 40a and 40b inside. As shown in FIG. 3, the magnetic force line emission surfaces of the target lower magnets 40 a and 40 b are preferably directed toward the inclined magnetic bodies 30 a and 30 b facing each other across the target, and the magnetic polarities thereof are opposed to the inclined magnetic bodies 30 a and 30 b. And the same polarity. Further, the magnetic force line emission surfaces of the target lower magnets 40a and 40b in the water cooling case 23 face each other with different polarities, and are combined with the yoke plate 41 on the opposite side to the magnetic force line emission surface to form a magnetic flux loop. The temperature-controlled cooling water 24 is passed through the water cooling case 23 to cool the backing plate 22, the water cooling case 23, and the target lower magnets 40a and 40b. In the first and second embodiments, when the target 10 is a magnetic material, the magnetic lines of force 28 and 31 emitted from the magnetic body 11a and the inclined magnetic body 30a are slightly absorbed in the target 10 and parallel to the target surface. Although the overall level of the magnetic flux density may be lowered, according to this configuration, most of the magnetic force lines 42 emitted from the target lower magnet 40a pass through the target and are further emitted from the gradient magnetic body 30a having the same polarity. Therefore, the amount of the magnetic force lines 43 absorbed by the target 10 is greatly reduced, and stronger magnetic force lines are formed substantially parallel to the target surface. Furthermore, in the case of the first and second embodiments, in the magnetic target, the parallel magnetic flux density on the target surface tends to decrease slightly in the central portion of the distance W between the magnetic bodies. Since the magnetic field lines 42 from the target lower magnet 40 leaking to the target surface supplement the parallel magnetic flux in the center of the target, the parallel magnetic flux density distribution on the target can be made more uniform. When the target 10 is a magnetic body, the target lower magnets 40a and 40b are preferably those having a stronger magnetic force as the target thickness is thicker, such as neodymium magnets, samarium cobalt magnets, and alnico magnets. However, when the magnetic target is as thin as 1 to 2 mm or when a non-magnetic material is used, there is no problem even with a low magnetic force such as a ferrite magnet.

  FIG. 4 is a schematic view showing a film forming apparatus 300 using the discharge electrode according to the third embodiment of the present invention. However, in the drawing, the discharge device 202 according to the third embodiment is used as an example, but the film formation device is formed using the discharge electrodes 200 and 201 according to the first and second embodiments. No problem. In the film forming apparatus using the discharge device of the present invention in this figure, the vacuum chamber 50 is connected to the exhaust pump 51 and the inside of the vacuum chamber 50 is exhausted. A substrate 54 is supported inside the vacuum chamber 50 by substrate holders 52 and 53, and a discharge electrode 203 is installed at a position facing the front surface of the substrate 54. The substrate 54 is a glass substrate or a silicon wafer, but may be a plastic film or a metal plate. In the case of a plastic film, a web coater type vacuum chamber provided with a film transport mechanism may be used. The discharge electrodes 200 to 202 in the first to third embodiments schematically show a single shape of the discharge partial cross section, but the actual cross section is a symmetric cross section having two discharge surfaces as shown in the figure, The discharge surface in the planar direction seen from above forms a loop with a donut-shaped circle or a racetrack-shaped oval. As a result, the number of rotations of electrons captured by the parallel magnetic flux can be increased, and the discharge efficiency can be improved. In the discharge electrode 103, the cathode 1 and the anode 27 are electrically insulated via the spacer 26, and the cathode 1 is connected to the plasma power source 56. Although the anode 27 is grounded in this configuration, there is no problem even if it is a support configuration in which electrical insulation is provided from the vacuum chamber 50 and connected to the anode polarity side of the plasma power source. As the plasma power source, a general plasma power source such as a DC power source, an AC power source, a high frequency power source, or a pulse power source can be applied. Further, the cooling water described in the third embodiment is passed through the cathode 1. (The illustration is omitted in FIG. 4) An adhesion preventing plate 58 supported by an adhesion preventing plate holder 57 is provided around the side surfaces of the substrate 54 and the discharge electrode 203 to reduce the adhesion of sputtered particles in the vacuum chamber 50. Further, the gas pipe 55 is connected through the deposition preventing plate 58. The gas pipe 55 is connected to the control valve 60 and the plasma gas supply source 59 and supplies plasma gas to the surface of the discharge electrode 203. In the plasma gas supply state, a voltage is applied from the plasma power source 56 to the cathode 1 to generate a magnetron discharge on the target surface of the discharge electrode 203. A film is formed on the substrate 54 by ionizing the gas by the main discharge and sputtering the target. The plasma gas is preferably an inert gas such as argon or helium, but can also be sputtered with an active gas such as nitrogen or oxygen. In that case, a film obtained by nitriding or oxidizing the target material can be formed. In the case of CVD film formation, a reactive CVD gas supply source 61 is provided in accordance with the plasma gas supply source 59, the control valve 62 is operated, and the reactive CVD gas is introduced into the chamber together with the plasma gas. Then, a CVD film is formed on the substrate 54 by decomposing and polymerizing the gas. The CVD gas is preferably a hydrocarbon gas, a silicon compound gas or a fluorine compound gas. Examples of the hydrocarbon gas include alkanes such as methane, ethane, propane, and butane, alkenes such as ethylene, propylene, and butene, and alkynes such as acetylene. As the silicon compound gas, silane, disilane, polysilane, siloxane, silanol, TEOS and the like are suitable. However, other organic silicon compound gases, Si-based hydrogen compounds, and halides may be used. Fluorine compound gases include fluorocarbon hydrogen and its derivatives such as tetrafluoromethane (CF4), hexafluoroethane (C2F6), trifluoromethane (CHF3), octafluorocyclobutene (C4F8), and sulfur hexafluoride. A gas such as (SF6) or nitrogen trifluoride (NF3) is suitable.

Next, examples of the present invention will be described in detail. As described in the background art, the target utilization efficiency of the non-magnetic target is generally about 20 to 30%, and the magnetic target is about 10 to 15%. The object of the present invention is to improve the target utilization efficiency about twice as much as usual, although it is a magnet and target fixing system. Further, the parallel magnetic flux density in the following examples was measured using a Tesla meter (model: TM-701) manufactured by Kanetec Corporation.
Example 1
A discharge electrode as shown in FIG. 1 was constructed as follows. The material of the target 10 was copper, the target width W2 was 42 mm, and the target thickness was 10 mm. The height H and width of the magnetic body 11 were 15 mm square, the material was SUS430, and the facing distance W between the magnetic bodies 11a and 11b was 40 mm. The target upper magnets 12a and 12b were neodymium magnets having a cross-sectional shape of 10 mm square, and the auxiliary magnets 14 were neodymium magnets having a cross-sectional shape of 10 mm width and 20 mm height. The yoke parts 13 and 15 and the yoke plate 16 are made of SUS430. The target press 20 and the backing plate 22 are made of copper, and the water cooling case 23 and the screw 21 are made of SUS304. Therefore, the target surface parallel magnetic flux density distribution of the discharge electrode 100 in this configuration was measured in the range of the width W and the height 2H. The result is shown in FIG. The vertical axis is the parallel magnetic flux density, the horizontal axis is the distance W between the magnetic bodies 11, and it is on the center C of W and the parallel magnetic flux density Bc at an arbitrary point in the range of the height 2H, The parallel magnetic flux density distribution in the range of ± 0.35 W width at the same height was −5% to + 15%, and it was confirmed that a uniform parallel magnetic flux density distribution within ± 20% was formed on the target 10. Further, as a tendency, it was confirmed that the parallel magnetic flux density at the height of 1.0 H was increased on average.

Therefore, sputter film formation was performed using the discharge electrode of this example with a film formation apparatus as shown in FIG. That is, in the film forming apparatus 300, the discharge electrode 200 is used in the discharge electrode 203 portion. The discharge electrode had a discharge area in a donut shape, and the outer diameter was 250 mm. The cooling water 24 and 19 are passed through the water cooling case 23 and the magnetic body 11 of the discharge electrode, and the water amount and the control temperature are used by using a water supply means and a temperature control means (not shown) so that the water temperature after cooling is 50 ° C. Adjusted. As the plasma power source 56, a DC power source having a capacity of 10 kW was used. The vacuum pump 51 was evacuated using a rotary pump, and the pressure in the vacuum chamber 50 was controlled to 1 Pa by pressure control means (not shown). The substrate 54 is a 250 mm diameter circular glass substrate, and the distance between the discharge electrode 103 and the substrate 54 is 100 mm. In the sputtering film formation, the plasma gas supply source 59 used argon gas, and the gas flow rate was 200 sccm. With this configuration, a DC power source was output at 6 KW and sputter deposition was performed. As a result, a copper thin film could be formed with a uniform thickness on the substrate. Next, CVD film formation was performed with the same equipment configuration as described above. The CVD gas supply source 61 uses HMDSO (hexamethyldisiloxane), the control valve 62 is operated to set the gas flow rate to 150 sccm, the argon gas of the plasma gas supply source 59 is set to 50 sccm, and both gases are mixed to form a vacuum chamber. 50. When CVD film formation was performed under these conditions, a CVD film mainly composed of SiO 2 could be uniformly formed on the surface of the substrate 54. However, discharge abnormalities such as arc discharge were slightly observed at the corners of the magnetic body 11 in the above two types of film formation, and a sputter or CVD film adhered to the opposite surface of the magnetic body 11, but the film formation was not affected. . Further, when the sputter deposition was continued and the target erosion depth proceeded to 9 mm, the target utilization efficiency was measured, and the target utilization efficiency was 50%.
(Example 2)
A discharge electrode as shown in FIG. 2 was constructed as follows. The angle θ of the inclined magnetic bodies 30a and 30b was 70 °, and the shapes and materials of the other members were the same as in Example 1. As a result, as shown in FIG. 6, with respect to the parallel magnetic flux density Bc at an arbitrary point, the parallel magnetic flux density distribution in the range of ± 0.35 W width at the same height as Bc is −5% to + 15% as in the first embodiment. It was confirmed that a uniform parallel magnetic flux density distribution within Bc ± 20% could be formed on the target 10. Further, as can be seen from comparison with FIG. 5, the concentration of the parallel magnetic flux density at the height of 1.0H corresponding to the corner of the magnetic body 11 is eliminated, and the parallel magnetic flux density is gradually increased from the surface of the target 10 to the height of 2H. A well-balanced distribution in the vertical direction was obtained.

Therefore, sputtering film formation and CVD film formation were performed with a film formation apparatus as shown in FIG. That is, the structure of the discharge electrode 201 is used for the discharge electrode 203 portion in the film forming apparatus 300. Except for the inclined shapes of the inclined magnetic bodies 30a and 30b, the same conditions as in Example 1 were used. As a result, as in Example 1, a uniform thin film could be formed on the substrate for both sputtering film formation and CVD film formation, and no discharge abnormality such as arc discharge occurred. Further, it was confirmed that the sputter deposition and the CVD film adhesion to the opposing surfaces (inclined surfaces) of the gradient magnetic bodies 30a and 30b were greatly reduced, and the film formation rate was improved from that in Example 1. When the sputter deposition was continued and the target erosion depth progressed to 9 mm, the target utilization efficiency was measured. As a result, the target utilization efficiency was 60%, and it was confirmed that the target utilization efficiency was further improved than in Example 1.
(Example 3)
A discharge electrode as shown in FIG. 3 was constructed as follows. In this example, the target 10 was made of nickel, which is a magnetic material, and the target shape was the same as in Examples 1 and 2. The target lower magnets 40a and 40b in the water-cooled case 23 are neodymium magnets, the surfaces facing the inclined magnetic bodies 30a and 30b are the magnetic force line emission surfaces, and the magnet width is 10 mm. Further, the magnetic pole property of the magnetic force line emission surface is set to the same polarity as that of the opposing gradient magnetic bodies 30a and 30b. The height of the target lower magnets 40a and 40b was 20 mm, and the magnet surface opposite to the target 10 was joined to each other by a yoke plate 41 formed of SUS430 to form a magnetic flux loop. Other configurations were the same as those in Example 2. As a result, as shown in FIG. 7, although the target is a magnetic material, the average magnetic flux density level is improved about twice, and the parallel magnetic flux density Bc at an arbitrary point is the same height as Bc. Thus, the parallel magnetic flux density distribution in the range of ± 0.35 W was also −10% to + 5%, and it was confirmed that a uniform parallel magnetic flux density distribution within Bc ± 20% could be formed on the target 10.

Therefore, sputtering film formation and CVD film formation were performed with a film formation apparatus as shown in FIG. That is, the discharge electrode 202 is used in the discharge electrode 203 portion of the film forming apparatus 300. And it was comprised on the conditions similar to Example 2 except that the target 10 was nickel and the target lower magnets 40a and 40b and the yoke plate 41 were provided. As a result, a nickel film was formed on the substrate uniformly by sputtering film formation, and a thin film mainly composed of SiO 2 was formed on the substrate by CVD film formation, and no discharge abnormality such as arc discharge occurred. When the sputter deposition was continued and the target erosion depth proceeded to 9 mm, the target utilization efficiency was measured and found to be 40%.
(Comparative Example 1)
As shown in FIG. 8, a comparative example in which a general discharge electrode 204 having a magnet only at the lower part of the target is used and a nonmagnetic target is sputtered is shown. In the discharge electrode 204, the cathode 72 has the same shape as that of the third embodiment having no target upper magnetic circuit member (gradient magnetic bodies 30a, 30b, target upper magnets 12a, 12b, etc.), and the periphery of the cathode 72 is an insulating member. The spacers 26 are separated from each other and covered with the anode 70. The shape of the target 10 was the same as in Examples 1 to 3, and the material was copper. Therefore, the surface magnetic field of the target 10 is formed only by the magnetic field loop formed by the target lower magnets 40 a and 40 b and the yoke plate 41. FIG. 9 shows the result of measuring the parallel magnetic flux density distribution on the target surface in the same manner as in the above example. As a result, with respect to the parallel magnetic flux density Bc at an arbitrary point, the variation of the parallel magnetic flux density distribution in the range of ± 0.35 W width at the same height as Bc is 0% to −70%, and the target 10 is very insignificant. It was confirmed that the magnetic flux density distribution was uniform. Further, sputtering film formation and CVD film formation were performed with a film forming apparatus as shown in FIG. That is, the discharge electrode 204 is used in the discharge electrode 203 portion of the film forming apparatus 300. The discharge electrode 204 was configured to have a discharge area in a donut shape as in Examples 1 to 3, and the outer diameter was about 250 mm. Plasma gas and CVD gas were the same as those in Examples 1-3. As a result, the copper thin film at the time of sputtering film formation and the thin film mainly composed of SiO 2 at the time of CVD film formation were deposited on the substrate thickest in the portion corresponding to the center C of the target 10, resulting in an uneven film thickness state. Further, when this sputtering film formation was continued and the target erosion depth proceeded to 9 mm, the target utilization efficiency was measured and found to be 25%.
(Comparative Example 2)
8 shows a comparative example in which the general discharge electrode 204 shown in FIG. 8 shown in the comparative example 1 is used and a magnetic target is sputtered. The target material was nickel. In this case, when the target thickness is 10 mm, which is the same as in Example 3, almost no parallel magnetic flux can be formed on the target. Therefore, the target is thinned to such an extent that the parallel magnetic flux can be formed, and the target 10 thickness is 3 mm. The configuration is the same as that of Comparative Example 1. Therefore, the surface magnetic field of the target 10 is formed only by the magnetic flux loop formed by the target lower magnets 40 a and 40 b and the yoke plate 41. FIG. 10 shows the result of measuring the parallel magnetic flux density distribution on the target surface in the same manner as in the above example. As a result, with respect to the parallel magnetic flux density Bc at an arbitrary point, the parallel magnetic flux density distribution in the range of ± 0.35 W width at the same height as Bc is 0% to −80%, which is a very non-uniform parallel magnetic flux density distribution. It was confirmed that Further, sputtering film formation and CVD film formation were performed with a film forming apparatus as shown in FIG. That is, the structure of the discharge electrode 204 was used for the discharge electrode 203 portion in the film forming apparatus 300, and the target 10 was made of 3 mm thick nickel. The discharge electrode 204 was configured to have a discharge area in a donut shape as in Examples 1 to 3, and the outer diameter was about 250 mm. As a result, the nickel thin film at the time of sputtering film formation and the SiO 2 thin film at the time of CVD film formation were deposited most thickly on the portion corresponding to the center C of the target 10, resulting in a very uneven film thickness state. Further, when this sputtering film formation was continued and the target erosion depth proceeded to 2 mm, the target utilization efficiency was measured and found to be 15%.
The results shown in the following examples and comparative examples are shown in a table.

Example 4
The electrode shown in FIG. 3 was configured as described in Example 3, and a film forming experiment by a sputtering method was performed in the film forming apparatus shown in FIG. At this time, a SUS304 plate having a thickness of 3 mm was used for the cover 211, and a very small magnetron plasma discharge was generated on the surface of the cover 211. This very small magnetron plasma discharge is an unwanted discharge that was not originally intended, but it did not affect the film forming function.
(Example 5)
When the film formation experiment shown in Example 4 was carried out by changing the cover 211 to a SUS430 plate having a thickness of 5 mm, unnecessary and unintended magnetron plasma discharge did not occur.

  The present invention can be applied not only to a sputtering film forming apparatus and a CVD film forming apparatus as a discharge electrode, but also to a surface treatment apparatus or an etching apparatus using plasma, and is not limited to these application ranges.

DESCRIPTION OF SYMBOLS 1 Cathode 10 Target 11a Magnetic body 11b Magnetic body 12a Target upper magnet 12b Target upper magnet 13 Yoke part 14 Auxiliary magnet 15 Yoke part 16 Yoke plate 17 Cover 18 Cover 19 Cooling water 20 Target pressing 21 Screw 22 Backing plate 23 Water cooling case 24 Cooling Water 25 O-ring 26 Spacer 27 Anode 30a Gradient magnetic body 30b Gradient magnetic body 31 Magnetic field line 40 Target lower magnet 41 York plate 42 Magnetic field line 43 Magnetic field line 50 Vacuum chamber 51 Vacuum pump 52 Substrate holder 53 Substrate holder 54 Substrate 55 Gas tube 56 Plasma power source 57 Protection plate holder 58 Protection plate 59 Plasma gas supply source 60 Control valve 61 Gas supply source for CVD 62 Control valve 70 Anode 71 Magnetic field line 72 Cathode 80 Target 81 Target upper part Stone 82 Target lower magnet 83 Magnetic field line 84 Magnetic field line 85 Cation 86 Sputtered particle 90 Target 91 Backing plate 92 Cooling shield 93 Target upper magnet 94 Target upper magnet 95 Target lower magnet 96 Target lower magnet 97 Yoke 98 Magnetic field line 99 Magnetic field line 110 Target 111 Magnetic field line 112 Magnetic field line 120 Target 121 Magnetic body 122 Magnetic body 123 Target lower magnet 124 Yoke 125 Magnetic field line 130 Target 131 Magnetic body 132 Magnetic body 133 Magnetic field line 140 Flat target 141 Target upper magnet 142 Target lower magnet 143 Magnetic body 144 Cation 145 Sputtered particle 146 Magnetic field line 147 Magnetic field lines 148 Yoke 149 Yoke 150 Cooling water 151 Magnetic body 152 Target upper magnet 153 Target lower magnet 200 Discharge electrode 201 Discharge electrode 202 Discharge electrode 203 Discharge electrode 204 Discharge electrode 205 Discharge electrode 211 Cover 300 Film forming apparatus

Claims (17)

In the discharge electrode having a flat plate target, the magnetic material is provided along both side edges on the surface side of the flat plate target, facing the flat plate target across the flat plate target, and on the opposite side of the flat plate target across the magnetic material. discharge electrodes, characterized in that it comprises a target upper magnet is opposite polarity relationship separating the flat plate target is provided in combination in contact with the magnetic body.   The discharge electrode according to claim 1, wherein a lower surface of the magnetic body is substantially the same as or above a surface of the flat plate target.   In a cross section perpendicular to the longitudinal direction of the flat plate target, the opposing surfaces between the magnetic bodies are inclined outward at an angle θ with respect to the normal direction of the flat plate target surface, and θ is in a range of 0 ° <θ ≦ 45 °. The discharge electrode according to claim 1 or 2, wherein:   There is a target lower magnet at the back surface side position of the flat plate target, which is a position facing the magnetic body across the flat plate target in the thickness direction of the flat plate target, and the direction of the magnetic force line emission of the target lower magnet is the flat plate target The discharge electrode according to any one of claims 1 to 3, wherein the magnetic body and the magnetic pole of the target lower magnet have the same polarity.   The discharge electrode according to any one of claims 1 to 4, wherein a surface-side magnetic field of the flat plate target forms a loop.   The magnetic flux loop on the surface side of the flat plate target is generated by a surface side magnetic circuit including at least the target upper magnet and a yoke, and the configuration of the surface side magnetic circuit excluding the surface on the discharge surface side of the flat plate target 6. The discharge electrode according to claim 5, wherein a magnetic shield made of a magnetic material is provided on at least a part of the member outside the component member. The discharge electrode according to claim 6, wherein the magnetic shield is provided around the upper magnet of the target.   8. The discharge electrode according to claim 1, further comprising an insulating cover on at least a part of the outermost peripheral surface of the electrode constituent member excluding the surface on the discharge surface side of the flat plate target. .   The discharge electrode according to any one of claims 4 to 8, wherein a magnetic field on the back surface side of the flat plate target forms a loop.   The discharge electrode according to claim 1, wherein the magnetic body and the target upper magnet have temperature control means.   The discharge electrode according to claim 4, wherein the target lower magnet has a temperature control means.   The discharge electrode according to claim 4, wherein the flat plate target is a magnetic material mainly composed of Fe, Co, or Ni. A discharge method for generating a discharge using a magnetic field formed on the surface of a flat plate target, the magnetic body being provided along both side edges on the surface side of the flat plate target and facing the flat plate target, is the magnetic and target upper magnet provided in combination in contact with body position facing the magnetic separating said flat target in the thickness direction of the flat plate target on the opposite side of the flat plate target at a magnetic There is a target lower magnet at the back surface side position of the flat plate target, the opposing magnetic poles of the target upper magnets are of opposite polarity, and the magnetic polarity of the target upper magnet and the target lower magnet that are opposed across the target thickness direction. Have the same polarity to form a substantially parallel magnetic field between the magnetic bodies on the target surface, and discharge using the magnetic field. Discharge wherein the generating. Arbitrary height h in the range of ± 0.35 W from the center of the width W between the magnetic bodies and a height direction in the magnetic field forming region defined by 2H with respect to the height H of the magnetic bodies in the range of 0 to 2H the distribution of the parallel magnetic flux density position, formed within Bc ± 20% with respect to the parallel flux density Bc widthwise position height direction the height h located at the center position of the W, by using the parallel magnetic flux The discharge method according to claim 13, wherein discharge is generated.   The discharge method according to claim 14, wherein the parallel magnetic flux density Bc is in a range of 10 mT to 500 mT.   A sputtering apparatus comprising the discharge electrode according to claim 1 as a sputtering source.   A thin film forming method, wherein a thin film is formed by introducing a gas into the sputtering apparatus according to claim 16 and sputtering a target.

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