JP6048319B2 - Magnetron sputtering equipment - Google Patents

Description

  The present invention relates to a magnetron sputtering apparatus that generates a plasma using a magnetic field and an electric field and sputters a target using the plasma.

  In a magnetron sputtering apparatus used in the manufacturing process of a semiconductor device, a target made of a film-forming material is placed in a vacuum vessel so as to face a substrate to be processed, and a magnetic field and an electric field are formed on the lower surface side of the target to generate plasma. The target is generated and sputtered by plasma ions. In order to obtain high in-plane uniformity for a film formed on the substrate to be processed, it is necessary to secure a large amount of sputtered particles scattered at a portion of the target that faces the peripheral edge of the substrate to be processed.

  FIG. 32 shows the distribution of the amount of sputtered particles scattered from the target 1000. As the distance from the target is increased, the crest of the peripheral portion (the portion where the amount of sputtered particles is scattered) is smoothed, and the surface of the substrate 10 to be processed is shown. Then, the uniformity of the in-plane distribution of sputtered particles is high.

  FIG. 33A shows an example of a magnet unit for forming a magnetic field on the target 1000. This magnet unit is configured by disposing an annular magnet 2001 along the peripheral edge of the target 1000 and disposing a magnet 2002 above the center of the target 1000. In the figure, P indicates plasma (hereinafter the same). FIG. 33B is a plan view of the magnet unit viewed from the target 1000 side, and FIG. 33C shows the erosion state of the target 1000 with the erosion depth enlarged (exaggerated). is there.

According to the magnet unit having such a configuration, a ring of a horizontal magnetic field H, that is, a race track, is formed near the lower surface of the target 1000 by a cusp magnetic field based on the outer magnet 2001 and a cusp magnetic field based on the inner magnet 2002. The The horizontal magnetic field H is a highly horizontal magnetic field. When an inert gas such as argon (Ar) gas is introduced into the vacuum container and a DC voltage is applied to the target 1000, for example, the argon gas is ionized by an electric field to generate electrons. These electrons drift due to a horizontal magnetic field and an electric field, and a high-density plasma is formed. Argon ions in the plasma sputter the target 1000 to sputter sputtered particles (metal particles), and film formation is performed on the substrate to be processed by the sputtered particles.
In the case of this example, since plasma is not generated immediately below the magnet 2002 at the center, erosion of the target 1000 is not formed in a portion where the plasma is not generated. The uniformity of the film formation distribution is poor.

  FIGS. 34A and 34B show another example of a magnet unit for forming a magnetic field on the target 1000. FIG. This magnet unit is configured by arranging an annular magnet 3002 along the periphery of the target 1000. In this case, it is possible to secure a large amount of sputtered particles scattered at the portion of the target 1000 that faces the peripheral edge of the substrate to be processed. However, no plasma is generated in the central portion of the target 1000, and the substrate to be processed is again. The uniformity of the film formation distribution on 10 is poor (FIG. 34C).

  Therefore, in practice, the magnet unit shown in FIGS. 35A and 35B may be used. 35A and 35B, reference numeral 1001 denotes an annular magnet, and a magnet 1002 having a polarity different from that of the magnet 1001 is disposed at an eccentric position inside the annular magnet 1001. These magnets 1001 and 1002 are attached to the rotating plate 1004 via the iron plate 1003, and the magnets 1001 and 1002 are rotated by the rotating mechanism 1005 with the eccentric position of the rotating plate 1004 as the center of rotation.

  However, when the annular magnet 1001 smaller than the target 1000 is revolved around the center of rotation, there is a lot of time during which the magnet 1001 makes a full discharge during most of the surface of the target 1000. For this reason, there is a concern that sputtered particles are reattached to a non-discharged region, and the particles are generated in the vacuum vessel, which causes a reduction in the processing yield of the substrate to be processed.

  In Patent Document 1, an annular moat (vault) is formed on the surface of the target on the side of the semiconductor wafer, and a permanent magnet is provided on the lower surface side of the rotatable yoke to form a unit. Although a magnetron plasma sputtering reactor reactor is described in FIG. 1, it does not suggest the present invention.

Japanese Patent Laid-Open No. 2001-316809: paragraphs 0031 to 0034, FIG.

  The present invention has been made under such circumstances, and an object of the present invention is to provide a magnetron capable of forming a film with high in-plane uniformity on a substrate to be processed and obtaining an erosion with a small bias in a target. It is to provide a sputtering apparatus.

The present invention is a magnetron sputtering apparatus in which a target is disposed so as to face a substrate to be processed placed in a vacuum vessel, and a magnet is provided on the back side of the target.
A power supply for applying a voltage to the target;
A base body made of a magnetically permeable material provided on the back side of the target;
A plurality of first magnets provided on a target side surface of the base body;
A second magnet provided on a surface of the base body opposite to the target,
The first magnet and the second magnet are disposed so as to form an annular horizontal magnetic field in the vicinity of the surface of the target on the substrate side ;
Each of the first magnet and the second magnet has different magnetic poles magnetized at a portion on the base body side and a portion on the opposite side of the base body,
The second magnet includes a plurality of magnets spaced from each other at a central portion of the base body and both side portions of the central portion, and the magnetic flux of the magnet located at the central portion diverges. And features.

The magnetron sputtering apparatus may have the following configuration.
(A) before SL base body is magnetized to the polarity of the magnetic pole portions of the base side of the second magnet, between the pole portions of the opposite side of the base body in the base body and the first magnet Magnetic flux is formed .
(B ) At least one of the first magnet and the second magnet is configured as an electromagnet, and a magnetic pole in a portion on the base body side and a magnetic pole in a portion on the opposite side of the base body according to the direction of the current of the electromagnetic coil, Is configured to reverse.
( C ) A moving mechanism for moving the base body along the surface of the base body is provided. At this time, the moving mechanism is a rotating mechanism for rotating the base body along the surface of the base body. Alternatively, the moving mechanism is a mechanism for linearly moving the base body along the surface of the base body.

  In the present invention, a first magnet is provided on the target side of a base body made of a magnetically permeable material, and a second magnet is provided on the side of the base body opposite to the target. Therefore, the degree of freedom in adjusting the position of the annular horizontal magnetic field formed in the vicinity of the target substrate side of the target is large, and therefore the horizontal magnetic field can be formed at a highly appropriate position. As a result, film formation with high in-plane uniformity can be performed on the substrate to be processed, and erosion with less bias can be obtained in the target, so that high usage efficiency can be obtained for the target.

It is a vertical side view of the magnetron sputtering apparatus which concerns on 1st Embodiment. It is explanatory drawing of the magnet unit provided in the said magnetron sputtering device. It is explanatory drawing which shows arrangement | positioning of the surface magnet provided in the said magnet unit, and its effect | action. It is explanatory drawing which shows arrangement | positioning of the back magnet provided in the said magnet unit. It is explanatory drawing of the magnet unit which concerns on a comparative example. It is explanatory drawing of the table magnet which concerns on the said comparative example. It is explanatory drawing of the magnet unit which concerns on the modification of 1st Embodiment. It is explanatory drawing of the surface magnet which concerns on the said modification. It is explanatory drawing of the magnet unit which concerns on the other modification of 1st Embodiment. It is explanatory drawing of the surface magnet which concerns on the said other modification. It is explanatory drawing which shows the modification of a back magnet. It is the 1st explanatory view of the magnet unit concerning a 2nd embodiment. It is the 2nd explanatory view of the magnet unit concerning a 2nd embodiment. It is a 1st explanatory view of a table magnet concerning a 2nd embodiment. It is the 3rd explanatory view of the magnet unit concerning a 2nd embodiment. It is a 4th explanatory view of the magnet unit concerning a 2nd embodiment. It is the 2nd explanatory view of a table magnet concerning a 2nd embodiment. It is explanatory drawing of the magnet unit which concerns on 3rd Embodiment. It is explanatory drawing of the table magnet which concerns on 3rd Embodiment. It is explanatory drawing of the magnet unit which concerns on 4th Embodiment. It is explanatory drawing of the table magnet which concerns on 4th Embodiment. It is the 1st explanatory view of the magnet unit concerning a 5th embodiment. It is the 1st explanatory view of the table magnet concerning a 5th embodiment. It is the 2nd explanatory view of the magnet unit concerning a 5th embodiment. It is the 2nd explanatory view of the table magnet concerning a 5th embodiment. It is the 1st explanatory view of the magnet unit concerning a 6th embodiment. It is the 2nd explanatory view of the magnet unit concerning a 6th embodiment. It is explanatory drawing of the table magnet which concerns on 6th Embodiment. It is explanatory drawing of the back magnet which concerns on 6th Embodiment. It is explanatory drawing of the magnet unit which concerns on the modification of 6th Embodiment. It is explanatory drawing of the table magnet which concerns on the modification of 6th Embodiment. It is explanatory drawing which shows the change of distribution of the amount of sputtered particles scattered from a target. It is explanatory drawing which shows the 1st example of the conventional magnet unit. It is explanatory drawing which shows the 2nd example of the conventional magnet unit. It is explanatory drawing which shows the 3rd example of the conventional magnet unit.

[First Embodiment]
An overall configuration of the magnetron sputtering apparatus according to the first embodiment of the present invention will be described with reference to a longitudinal side view of FIG. In the figure, reference numeral 2 denotes a vacuum vessel 2 made of, for example, aluminum (Al) and grounded. The vacuum vessel 2 has an opening at the ceiling, and the target electrode 3 is provided so as to close the opening 21. The target electrode 3 is configured by bonding a conductive base plate 32 made of, for example, copper (Cu) or aluminum to the upper surface of a target 31 made of a film forming material, for example, tungsten (W). For example, the target 31 is configured to have a circular planar shape, and the diameter thereof is set to, for example, 500 mm in a range of 400 to 500 mm so as to be larger than a semiconductor wafer (hereinafter referred to as “wafer”) 10 forming a substrate to be processed. Yes.

  The base plate 32 is formed larger than the target 31, and the target electrode 3 is provided so that the peripheral area of the lower surface of the base plate 32 is placed around the opening 21 of the vacuum vessel 2. An annular insulating member 22 is provided between the peripheral edge of the base plate 32 and the vacuum vessel 2, and the target electrode 3 is fixed to the vacuum vessel 2 while being electrically insulated from the vacuum vessel 2. Has been. Further, a negative DC voltage is applied to the target electrode 3 by the power supply unit 33.

  A placement unit 4 on which the wafer 10 is placed in a horizontal state is provided in the vacuum vessel 2 so as to face the target electrode 3 in parallel. The mounting unit 4 is configured as an electrode (counter electrode) made of, for example, aluminum, and is connected to a high frequency power supply unit 41 that supplies high frequency power. The mounting unit 4 is configured to be movable up and down between a transfer position at which the wafer 10 is carried into and out of the vacuum chamber 2 and a processing position at the time of sputtering by an elevating mechanism 42. In the processing position, for example, the distance h between the upper surface of the wafer 10 on the mounting unit 4 and the lower surface of the target 31 before erosion is set within a range of 10 mm to 30 mm, for example.

  A heater 43 that forms a heating mechanism is built in the mounting portion 4 so that the wafer 10 is heated to, for example, 400 ° C. Further, the mounting unit 4 is provided with a push-up pin (not shown) for delivering the wafer 10 between the mounting unit 4 and an external transfer arm (not shown).

  Inside the vacuum vessel 2, an annular chamber shield member 44 is provided so as to surround the lower side of the target electrode 3 along the circumferential direction, and the side of the mounting portion 4 is surrounded along the circumferential direction. Thus, an annular holder shield member 45 is provided. These are provided in order to suppress adhesion of sputtered particles to the inner wall of the vacuum vessel 2, and are made of a conductor such as aluminum or an alloy having aluminum as a base material. The chamber shield member 44 is connected to, for example, the inner wall of the ceiling portion of the vacuum vessel 2 and is grounded via the vacuum vessel 2. Further, the holder shield member 45 is grounded so that the mounting portion 4 is grounded via the holder shield member 45.

  Further, the vacuum vessel 2 is connected to a vacuum pump 24 which is a vacuum exhaust mechanism through an exhaust passage 23 and is connected to a supply source 26 of an inert gas, for example, Ar gas, through a supply passage 25. In the figure, reference numeral 27 denotes a transfer port for the wafer 10 which can be opened and closed by the gate valve 28.

  A magnet unit is provided on the upper side of the target electrode 3 so as to be close to the target electrode 3. 2 is a longitudinal sectional view of the magnet unit, FIG. 3 is a plan view of the magnet unit viewed from the target side, and FIG. 4 is a view of the magnet unit viewed from the upper side. In FIG. 2, the description of the base plate 32 is omitted, and the heights of the magnets 501 and 502 are enlarged (exaggerated) (hereinafter, the same applies to the longitudinal sectional view of the magnet unit).

  The magnet unit includes a support plate 51 that is a circular base body having a diameter slightly larger than the diameter of the target 31, nine magnets 501 provided on the surface (lower surface) of the support plate 51 on the target 31 side, And nine magnets 502 provided on the surface (upper surface) opposite to the target 31 of the support plate 51. The support plate 51 is attached to the rotation mechanism 56 via the rotation shaft 55, and the rotation center thereof is set at a position slightly decentered from the center of the support plate 51.

  3, C1 indicates the center of the support plate 51, C2 indicates the center of the target 31, and the magnet unit of FIG. 2 includes the support plate 51, the magnet 501, and the magnet 501 at the position AA ′ shown in FIG. A positional relationship 502 is schematically shown. As described above, the diameter of the target 31 in this example is 500 mm, and the diameter of the support plate 51 is 510 mm. The support plate 51 is made of a magnetically permeable material such as iron. In this specification, the lower surface side of the support plate 51 is referred to as the front side, and the upper surface side is referred to as the back side. Further, the front side magnet 501 of the support plate 51 is referred to as “front magnet”, and the back side magnet 502 is referred to as “back magnet”. The front magnet 501 corresponds to the first magnet of the present invention, and the back magnet 502 corresponds to the second magnet.

Each of the front magnets 501 is formed in a columnar shape and has a surface magnetic flux density of, for example, about 2 to 3 G (2.0 × 10 ^{−4 to} 3.0 × 10 ⁻⁴ T). In these table magnets 501, as shown in FIG. 3, nine magnets 501 are arranged in a matrix of 3 rows and 3 columns. Each front magnet 501 is magnetized with magnetic poles that are different from each other vertically, and the lower magnetic pole has N and S poles arranged in a staggered pattern. The center part of the front magnet 501 located in the center part is located in the center part of the support plate 51, and the lower magnetic pole of the front magnet 501 is an N pole. Further, the central portion of the magnet 501 located at the corner in the matrix arrangement is located near the periphery of the support plate 51, for example, closer to the inside from the periphery. Hereinafter, the magnetic pole on the lower surface side of the front magnet 501 and the magnetic pole on the upper surface side of the back magnet 502 are both referred to as “front magnetic pole” for convenience.

  The back magnets 502 are each formed in a cylindrical shape, and those having the same surface magnetic flux density as the front magnet 501 are used. As shown in FIG. 4, these back magnets 502 have nine magnets 502 arranged in a matrix of three rows and three columns in a narrow region closer to the center of the support plate 51 than the region where the front magnets 501 are arranged. Has been. The nine back magnets 502 are vertically magnetized with different magnetic poles, the front magnetic poles are all S poles, and the central portion of the magnet 502 located in the center is close to the central portion of the support plate 51. positioned.

  The centers of the center magnets 501 and 502 of the front magnet 501 and the back magnet 502 are actually slightly decentered from the center of the support plate 51 so as not to interfere with the rotating shaft that rotates the support plate 51. The front magnet 501 and the back magnet 502 of this example are both formed in the same size, and the diameter is set to 30 mm and the height is set to 15 mm.

  Around the magnet unit described above, a cooling jacket 57 is provided so as to cover the upper surface and side surfaces of the magnet unit while forming a space in which the support plate 51, the front magnet 501 and the back magnet 502 rotate. . A cooling medium flow path 58 is formed inside the cooling jacket 57, and a cooling medium adjusted to a predetermined temperature, for example, cooling water, is circulated and supplied from the supply unit 59 into the flow path 58, so that the magnet unit and The target electrode 3 is cooled via the magnet unit.

  The magnetron sputtering apparatus having the above-described configuration includes a power supply operation from the power supply unit 33 and the high frequency power supply unit 41, an Ar gas supply operation, a lifting operation of the mounting unit 4 by the lifting mechanism 42, and a magnet unit by the rotating mechanism 56. A control unit 100 for controlling the rotation operation, the exhaust operation of the vacuum vessel 2 by the vacuum pump 24, the heating operation by the heater 43, and the like. The control unit 100 includes, for example, a computer including a CPU and a storage unit (not shown). The storage unit includes steps (commands) for control necessary for film formation on the wafer 10 by the magnetron sputtering apparatus. ) The grouped program is stored. This program is stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card, and installed in the computer therefrom.

  Next, the operation of the above magnetron sputtering apparatus will be described. First, the transfer port 27 of the vacuum container 2 is opened, the placement unit 4 is placed at the delivery position, and the wafer 10 is delivered to the placement unit 4 by a cooperative operation of an external transport mechanism and push-up pins (not shown). Next, the transfer port 27 is closed, and the placement unit 4 is raised to the processing position. In addition, Ar gas is introduced into the vacuum vessel 2 and evacuated by the vacuum pump 24 to maintain the inside of the vacuum vessel 2 at a predetermined degree of vacuum, for example, 11 to 100 mTorr (1.46 to 13.3 Pa).

  On the other hand, while rotating the magnet unit by the rotation mechanism 56, a negative DC voltage of, for example, 100 W to 3 kW is applied from the power supply unit 33 to the target electrode 3, and several hundred KHz to hundreds of hundreds of KHz to hundreds are applied from the high frequency power supply unit 41 to the mounting unit 4. A high frequency voltage of about MH is applied about 10 W to 1 kW. Further, the cooling water is always passed through the flow path 58 of the cooling jacket 57.

  When a DC voltage is applied to the target electrode 3, the Ar gas is ionized by the surrounding electric field to generate electrons. At this time, a cusp magnetic field is formed below the surface magnet 501 of the magnet unit, and this cusp magnetic field continuously forms a horizontal magnetic field H in the vicinity of the surface (surface to be sputtered) of the target 31 (FIG. 3). . Hereinafter, the influence on the horizontal magnetic field H by providing the back magnet 502 will be described.

  As shown in FIGS. 2 and 3, the N poles of the magnetic poles on the support plate 51 side of the nine front magnets 501 arranged in a matrix form are one less than the S poles. On the other hand, the magnetic poles on the support plate 51 side of the back magnet 502 are all N poles, and the magnetic flux MF1 diverges from the S poles on the center side of the back magnet 502. Since the support plate 51 is made of iron as described above, the support plate 51 has an N pole, and the magnetic flux MF2 extends from the support plate 51 to the S pole that is the front pole of the front magnet 501. FIG. 2 is a diagram when the arrangement of the front magnetic poles of the front magnet 501 is viewed in a longitudinal section along the S pole, N pole, and S pole (AA ′ section in FIG. 3), and the state at this time Is shown.

  On the other hand, since the front magnet 501 and the back magnet 502 located at the center of the support plate 51 are coupled, as shown in FIG. 2, the outer surface from the N pole that is the front magnetic pole of the front magnet 501 at the center is shown. A magnetic flux MF3 extends to the S pole, which is a magnetic pole. Since the support plate 51 has an N pole, the N pole on the support plate 51 side of the surrounding front magnet 501 is apparently strong. Therefore, the magnetic flux MF3 extending from the north pole of the front surface magnet 501 to the south pole of the surrounding front magnet 501 and the north pole as the magnetic pole on the support plate 51 side of the surrounding front magnet 501 extend to the south pole as the front magnetic pole. The magnetic flux MF4 is coupled. As a result of this coupling, a horizontal magnetic field H is formed at a position closer to the peripheral surface magnet 501 side than the central surface magnet 501. More specifically, the horizontal magnetic field H is formed in the vicinity of the lower surface side of the target 31 with continuous cusp magnetic fields.

  Furthermore, since the support plate 51 has an N pole, the magnetic flux MF2 extends from the peripheral portion of the support plate 51 to the S pole that is the front magnetic pole of the surrounding front magnet 501. That is, when attention is paid to a region outside the surrounding front magnet 501 whose front magnetic pole is the S pole (on the side opposite to the front surface magnet 501 in the center), this magnetic flux MF2 and the support plate 51 side of the front magnet 501 are arranged. A horizontal magnetic field is formed closer to the outside than directly below the front magnet 501 by the magnetic flux MF4 extending from the N pole to the S pole of the front magnetic pole. Thus, as shown in FIG. 3, an annular horizontal magnetic field H is formed around the lower side of the south pole, which is the front pole of the front magnet 501.

  An annular horizontal magnetic field is not formed in the region below the center magnet 501 and the surface magnet 501 around which the surface magnetic pole is N-pole. In FIG. 3, a circle surrounding a front magnetic pole corresponds to a state in which a region below the front magnetic pole is surrounded by an annular horizontal magnetic field H.

  As described above, since a DC voltage is applied to the target 31, an electric field is formed below the target 31, and argon gas is ionized by this electric field to generate electrons. The electrons drift along the horizontal magnetic field H while being entangled with the annular horizontal magnetic field H formed by the mechanism described above. The drifted electrons further collide with the argon gas and cause ionization to generate plasma P. The direction of movement of electrons drifting around the lower region of the surrounding front magnet 501 whose front pole is the S pole is counterclockwise when viewing the target 31 from the wafer 10.

  As shown in FIG. 3, in this magnet unit, the front magnets 501 whose front poles are S poles are distributed along the support plate 51, and a horizontal magnetic field H (annularly spreading around these front magnets 501). Plasma P) is formed. When the support plate 51 is rotated around the vertical axis at a position eccentric from the center by the rotation mechanism 56, the plasma P moves along the trajectory through which each horizontal magnetic field H passes, and over the entire surface of the target 31. Erosion can be generated more uniformly.

  In addition, since the in-plane uniformity of erosion of the target 31 is high in this way, film formation with high in-plane uniformity is possible even when sputtering is performed with the distance between the wafer 10 and the target 31 close to, for example, 30 mm or less. The result can be obtained. By generating sputtered particles at a position close to the wafer 10, loss due to scattering of the sputtered particles to the outside of the wafer 10 can be reduced, and film formation efficiency can be improved. From the viewpoint of generating stable discharge, the distance h between the target 31 and the wafer 10 is preferably set to 10 mm or more.

  According to the above-described embodiment, there are the following effects. A front magnet 501 (first magnet) is provided on the target 31 side of the base body 51 made of a magnetically permeable material, and a back magnet 502 (second magnet) is provided on the opposite surface. Therefore, the degree of freedom in adjusting the position of the annular horizontal magnetic field H formed near the target 10 on the wafer 10 side is large, and therefore the horizontal magnetic field H can be formed at a highly appropriate position. As a result, film formation with high in-plane uniformity can be performed on the wafer 10, and erosion with little bias can be obtained in the target 31, so that high usage efficiency can be obtained for the target 31.

  As shown in FIGS. 2 and 3, a back magnet 502 is provided, and an annular horizontal magnetic field H is concentrated at a position close to the surrounding front magnet 501 side by using magnetic fluxes MF3-MF4 and MF2-MF4. As a result, a relatively strong plasma P can be generated to improve the deposition rate.

  FIG. 5 shows a configuration of a comparative example in which the back magnet 502 is not used in the magnet unit used in the first embodiment. FIG. 6 is a plan view of the magnet unit shown in FIG. 5 when viewed from below. In the explanatory diagrams of the various embodiments and comparative examples shown below, the same reference numerals as those shown in these drawings are attached to the same components as those shown in FIGS. .

In the magnet unit shown in FIG. 5, the magnetic pole on the support plate 51 side of the front magnet 501 has one more S pole than the N pole, but unlike the example shown in FIG. 2, the back magnet 502 is not provided. The support plate 51 is relatively weak and has an S pole.
Since the support plate 51 has an S pole, a divergent magnetic flux MF5 is formed in the surrounding front magnet 501, and therefore, in a region below the surrounding front magnet 501 located on the line AA ′ in FIG. 6. No horizontal magnetic field H is formed.

  On the other hand, in the center table magnet 501 having the north pole as the front pole, a magnetic flux MF3 extending from the north pole of the center table magnet 501 to the south pole as the front pole of the surrounding table magnet 501 is formed. Further, a magnetic flux MF4 is formed extending from the S pole, which is the magnetic pole on the support plate 51 side, of the center magnet 501 to the N pole, which is the front pole.

  As a result of the coupling of these magnetic fluxes MF3 and MF4, a horizontal magnetic field H is formed at a position close to the front magnet 501 side of the central portion where the front magnetic pole is the N pole as shown on the A-A 'line in FIG. However, as described above, since the S pole on which the support plate 51 is charged is relatively weak, the magnetic flux density of the magnetic flux MF4 is small and the coupling of the magnetic fluxes MF3 and MF4 is also weak. As a result, the region where the horizontal magnetic field H is formed becomes wider and the plasma P becomes weaker than in the case of FIGS.

  Therefore, it can be said that when the back magnet 502 is provided, it is possible to concentrate in a relatively narrow region to form the annular horizontal magnetic field H, and to improve the film forming speed.

  FIGS. 7 and 8 show the installation of the back magnet 502 without providing the back magnet 502 at the center of the nine back magnets 502 arranged in a matrix in the magnet unit used in the first embodiment. The example which reduced the number is shown.

  By reducing the number of back magnets 502, the coupling between the front magnet 501 located at the center and the back magnet 502 is weakened, which is the front magnetic pole of the front magnet 501 at the center compared to the magnet unit of FIG. The magnetic flux MF3 extending from the N pole to the S pole, which is the surrounding front magnetic pole, is weakened. As a result, the coupling of the magnetic fluxes MF3 and MF4 is weakened, and the formation position of the horizontal magnetic field H moves to the center side. On the other hand, by reducing the number of back magnets 502, the magnetic field MF2 extending from the peripheral edge of the support plate 51 to the south pole which is the front magnetic pole of the surrounding front magnet 501 is weakened, and the horizontal magnetic field H formed by the magnetic flux MF4 is reduced. It moves to the peripheral edge side of the support plate 51.

  Due to these actions, the region in which the horizontal magnetic field H shown in FIG. 8 is formed is slightly expanded compared to the example of FIG. 3, and the intensity of the plasma P formed by the horizontal magnetic field H is also reduced. However, the effect of concentrating the horizontal magnetic field H can still be obtained as compared with the example of FIG.

  FIG. 9 and FIG. 10 show the installation of the front magnet 501 without providing the central surface magnet 501 among the nine front magnets 501 arranged in a matrix in the magnet unit used in the first embodiment. The example which reduced the number is shown.

By not providing the front magnet 501 located at the center, the magnetic flux MF2 ′ extends from the center of the support plate 51 to the south pole that is the front magnetic pole of the front magnet 501. Due to the action of the magnetic fluxes MF4 and MF2 ′, the horizontal magnetic field H is formed at a position closer to the surrounding front magnet 501 side as compared with the magnet unit of FIG. Further, by reducing the number of the front magnet 501 whose pole on the support plate 51 side is the S pole, the magnetic fluxes MF2 and MF2 ′ extending from the support plate 51 are also strengthened. Move to the front magnet 501 side.
By these actions, the region where the horizontal magnetic field H shown in FIG. 10 is formed is concentrated in a narrower region than the example of FIG. 3, and the intensity of the plasma P is improved.

  Here, the shape and arrangement of the back magnet 502 are not limited to the example in which nine cylindrical magnets 502 are arranged in a matrix as shown in FIG. For example, as shown in FIG. 11A, surrounding back magnets 502 may be arranged in a cross shape on the front, back, left and right of the back magnet 502 in the center. Further, as shown in FIG. 11B, an annular back magnet 502a may be disposed around the back magnet 502 in the center of the cylindrical shape. Further, the shape of the back magnet 502 is not limited to a cylindrical shape or an annular shape, and rectangular or cubic blocks may be arranged in a matrix shape or a cross shape.

[Second Embodiment]
12 to 17 show an example of a magnet unit in which the front magnet 501 is configured using an electromagnet capable of reversing the magnetic poles according to the current direction of the electromagnetic coil 503. In this example, all the magnetic poles on the support plate 51 side of the back magnet 502 are S poles. The entire configuration of the magnetron sputtering apparatus is the same as that described with reference to FIG.

  For example, as shown in FIG. 14, at a certain timing, the magnetic poles of the front magnet 501 are set so that the N and S poles of the front magnetic poles viewed from the target 31 side of the magnet unit are arranged in a zigzag pattern. (The arrangement of the front magnetic poles in FIG. 14 is the same as that of the first embodiment shown in FIG. 3). At this time, the magnetic pole on the support plate 51 side of the front magnet 501 has one more S pole than the N pole, and all the magnetic poles on the support plate 51 side of the back magnet 502 are S poles. The plate 51 has an S pole (FIGS. 12 and 13).

  When attention is paid to the front magnet 501 on the AA ′ line shown in FIG. 14 (FIG. 12), a divergent magnetic flux MF5 is formed in the surrounding front magnet 501 whose front pole is the S pole. A horizontal magnetic field H is not formed. On the other hand, in the central table magnet 501 whose front magnetic pole is N pole, the magnetic flux MF3 extending from the north pole of the central table magnet 501 to the S pole which is the front magnetic pole of the surrounding front magnet 501 and the central table magnet. The magnetic flux MF4 extending from the S pole as the magnetic pole on the support plate 51 side to the N pole as the front pole is coupled. As a result of this coupling, a horizontal magnetic field H is formed at a position close to the front magnet 501 side of the central portion where the front magnetic pole is the N pole as shown on the A-A 'line in FIG.

When the state of the front magnet 501 on the BB ′ line shown in FIG. 14 is viewed at the same timing (FIG. 13), all the front magnets 501 arranged on the BB ′ line have magnetic poles on the support plate 51 side. Magnetic fluxes MF4, MF2, and MF2 ′ extending from a certain S pole to an N pole that is a front magnetic pole are formed. As a result, a horizontal magnetic field H is formed at a position close to each table magnet 501 side whose surface magnetic pole is an N pole as shown on the line BB ′ in FIG.
Depending on the state of the front magnet 501, as shown in FIG. 14, an annular horizontal magnetic field H is formed around the lower side of the front magnet 501 whose front pole is an N pole.

  Next, after a predetermined time has elapsed since the state shown in FIGS. 12 to 14 is formed, the direction of the current of the electromagnetic coil 503 of each front magnet 501 is reversed, and the arrangement of the N pole and S pole of the front magnetic pole is reversed. Is in the state shown in FIG. At this time, the magnetic pole on the support plate 51 side of the front magnet 501 has one S pole less than the N pole, but all the magnetic poles on the support plate 51 side of the back magnet 502 are S poles. The support plate 51 has an S pole (FIGS. 15 and 16).

  When attention is paid to the front magnet 501 on the AA ′ line shown in FIG. 17 (FIG. 15), the magnetic flux MF3 extending from the north pole of the surrounding front magnet 501 to the south pole which is the front magnetic pole of the front center magnet 501. And the magnetic flux MF4 extending from the N pole that is the magnetic pole on the support plate 51 side of the surrounding front magnet 501 to the S pole that is the front magnetic pole. Further, since the support plate 51 has an S pole, the magnetic flux MF2 extends from the peripheral portion of the support plate 51 to the N pole, which is the front magnetic pole of the surrounding front magnet 501, and N on the support plate 51 side of the front magnet. A magnetic flux MF4 extending from the pole to the S pole of the front pole is formed. By the action of these magnetic fluxes MF3-MF4 and MF2-MF4, a horizontal magnetic field H is formed at a position close to the surrounding front magnet 501 side where the front magnetic pole is an N pole as shown on the line AA 'in FIG. The

When the state of the front magnet 501 on the BB ′ line shown in FIG. 14 is seen at the same timing (FIG. 16), the front magnetic poles of all the front magnets 501 arranged on the BB ′ line are S poles. The horizontal magnetic field H is not formed because the divergent magnetic flux MF is formed.
Depending on the state of the front magnet 501, as shown in FIG. 17, an annular horizontal magnetic field H is formed around the lower side of the surrounding front magnet 501 whose front magnetic pole is N-pole.

  As described above, the front magnetic pole of the front magnet 501 is periodically inverted between the N pole and the S pole by using the electromagnetic coil 503, so that an annular horizontal magnetic field as shown in FIGS. The position where H is formed is switched within the surface of the support plate 51. Therefore, by rotating the support plate 51 while periodically reversing the front magnetic pole of the front magnet 501, it becomes possible to use the plasma P generated by the horizontal magnetic field H dispersed in the surface of the support plate 51. This contributes to improvement of uniformity in time and efficient use of the target 31.

[Third Embodiment]
18A, 18B, and 19 show an example in which a back magnet 502 is provided in a magnet unit that includes an annular front magnet 501a. The magnetron sputtering apparatus provided with this magnet unit is different from the magnetron sputtering apparatus according to the first embodiment shown in FIG. 1 in that the rotating shaft 55 and the rotating mechanism 56 for rotating the support plate 51 are not provided.

  As shown in FIGS. 18 (a) and 19, the magnet unit of this example has an annular front magnet 501a arranged on the lower surface of the peripheral edge of the disc-shaped support plate 51 so as to extend downward, and the support plate The 51-side pole is the N pole and the front pole is the S pole. On the other hand, on the upper surface side of the support plate 51, for example, nine back magnets 502 are arranged in a matrix shape, and the front magnetic poles are all S poles, as in the example of FIG.

When the front magnet 501a and the back magnet 502 are arranged in this way, since the magnetic poles on the support plate 51 side of the magnets 501a and 502 are all N poles, the support plate 51 has N poles. As a result, as shown in FIG. 18 (a), the magnetic flux MF2 'extends from the center side of the support plate 51 to the south pole, which is the front pole of the front magnet 501a, and an annular horizontal magnetic field H is formed inside the front magnet 501a. Can be formed (FIG. 19)). At this time, the region where the magnetic flux MF2 ′ is formed can be adjusted by adjusting the number of the back magnets 502 installed, the surface magnetic flux density of each back magnet 502, and the like. As a result, the region where the horizontal magnetic field H is formed, that is, the region where the plasma P is generated can be expanded, and the target 31 as shown in FIG. 18B as compared with the prior art described with reference to FIG. It is possible to improve the use efficiency and to form a film with good in-plane uniformity.
As described above, in the third embodiment, the case where the support plate 51 is not rotated has been described. However, the rotation shaft 55 and the rotation mechanism 56 that rotate as necessary are provided, and the support plate 51 is rotated around the vertical axis. Of course, it may be allowed to.

[Fourth Embodiment]
20 and 21 show examples of magnet units in which rectangular parallelepiped front magnets 501b are radially arranged around the center of the support plate 51 in the radial direction. About the whole structure of the magnetron sputtering apparatus provided with the magnet unit of this example, the support plate 51 is disposed so that the center of the support plate 51 coincides with the center of the target 31, and the support plate 51 is disposed around the vertical axis passing through the center. The example is the same as that described with reference to FIG.

  As shown in FIG. 21, the front magnet 501 b of this example is formed as a rectangular parallelepiped block whose planar shape viewed from the target 31 side is an elongated rectangle, and the four front magnets 501 b are the central part of the support plate 51. It is arranged in a cross shape so as to extend in the radial direction across the wall. Four table magnets 501b are arranged in an X shape so as to extend in the radial direction across the central portion at an intermediate position between the table magnets 501b arranged in a cross shape and adjacent in the circumferential direction. . The length of the long side of each table magnet 501b viewed from the target 31 side is adjusted so that the table magnets 501b do not contact each other.

  As shown in FIG. 20, in this example, the front magnetic poles of all the front magnets 501b are S poles, and the poles on the support plate 51 side are N poles. Further, with respect to the back magnet 502, since the magnetic poles on the support plate 51 side are all N poles, the support plate 51 has N poles. The arrangement state of the back magnet 502 is not particularly limited. For example, the arrangement illustrated in FIGS. 4 and 11A and 11B may be employed.

  In the magnet unit in which the front magnet 501b and the back magnet 502 are arranged as described above, the state at the position AA ′ in FIG. 21 shows a support plate around the front magnet 501b as shown in FIG. Magnetic flux MF4 extending from the N pole as the magnetic pole on the 51 side to the S pole as the front magnetic pole, and magnetic fluxes MF2 and MF2 ′ extending from the support plate 51 bearing the N pole to the S pole as the front magnetic pole of the front magnet 501 are formed. The

  By the action of these magnetic fluxes MF2-MF4 and MF2'-MF4, an annular horizontal magnetic field H is formed around the lower side of each table magnet 501b as shown in FIG. In this example, each horizontal magnetic field H has a shape radially extending from the center of the support plate 51 in a radial direction corresponding to the planar shape of the front magnet 501b as viewed from the target 31 side. For this reason, by rotating the support plate 51 around the center, it is possible to perform film formation with high use efficiency of the target 31 and good in-plane uniformity.

[Fifth Embodiment]
In the fifth embodiment shown in FIG. 22 to FIG. 25, an electromagnetic coil 503 is provided, and the back magnet 502 is configured by an electromagnet capable of reversing the magnetic poles according to the direction of current, and the front magnet 501b The point which divided | segmented a part in radial direction and the point which replaced the front magnetic pole from the S pole to the N pole by half the front magnet 501b differ from the magnet unit which concerns on 4th Embodiment.

  As shown in FIGS. 23 and 25, in the magnet unit of this example, in the fourth embodiment shown in FIG. 21, the front magnets 501b having relatively long long sides extending in the direction crossing the cross are each in the radial direction. It is divided into two. As a result, a total of twelve front magnets 501 b are radially arranged on the support plate 51 around the center of the support plate 51 so as to extend in the radial direction.

In these table magnets 501b, out of the eight table magnets 501b arranged in a cross shape, two on the center side forming the vertical line of the cross, two on the outer side forming the horizontal line, and X-shaped Among the four table magnets 501b arranged in the left side, two of the table magnets 501b that form a straight line that goes up to the left, for a total of six table magnets 501b, have N poles for the front pole and S poles for the support plate 51 side. Are arranged as follows. For the remaining six front magnets 501b, the front magnetic pole is the S pole and the magnetic pole on the support plate 51 side is the N pole.
Further, in the magnet unit of this example, an electromagnetic coil 503 is provided on the back magnet 502, and the magnetic pole can be reversed according to the direction of current.

  Here, for example, as shown in FIG. 22, it is assumed that the current direction of the electromagnetic coil 503 is set so that all the magnetic poles on the support plate 51 side of the back magnet 502 become N poles at a certain timing. Since the front magnet 501 has the same number of magnetic poles on the support plate 51 side as the S pole and the N pole, the support plate 51 has an N pole under the influence of the magnetic poles of the back magnet 502.

  At this time, in the front magnet 501b on the AA ′ line shown in FIG. 23, the magnetic flux MF3 extending from the north pole of the outer front magnet 501b to the south pole that is the front magnetic pole of the front side magnet 501b, and the center side The magnetic flux MF4 extending from the N pole that is the magnetic pole on the support plate 51 side of the front magnet 501b to the S pole that is the front magnetic pole is coupled. Further, since the support plate 51 has an N pole, the magnetic flux MF2 ′ extends from the center of the support plate 51 to the S pole, which is the front magnetic pole of the front side magnet 501b, and the support plate 51 of the front magnet. A magnetic flux MF4 extending from the N pole on the side to the S pole of the front magnetic pole is formed.

Due to the action of these magnetic fluxes MF3-MF4 and MF2′-MF4, an annular horizontal magnetic field H is formed in the lower region of the center-side table magnet 501b whose front pole is the S pole as shown on the line AA ′ in FIG. It is formed.
On the other hand, since the support plate 51 has an N pole, a divergent magnetic flux MF5 is formed in the outer front magnet 501b, and therefore, below the outer front magnet 501b located on the line AA ′ in FIG. A horizontal magnetic field H is not formed in the region.

Also in the other front magnet 501b, an annular horizontal magnetic field H is formed in the lower region of the front magnet 501b whose front pole is the S pole, and this horizontal region is formed in the lower region of the front magnet 501b whose front pole is the N pole. The magnetic field H is not formed.
As a result, as shown in FIG. 23, the plasma P can be generated in a state where the horizontal magnetic field H is dispersed in the plane of the support plate 51.

  Next, after a predetermined time has elapsed since the state shown in FIGS. 22 and 23 is formed, the current direction of the electromagnetic coil 503 of each back magnet 502 is reversed, and the magnetic pole on the support plate 51 side is set to the S pole. (FIG. 24). As a result, the support plate 51 has an S pole under the influence of the magnetic poles of the back magnet 502.

  At this time, in the front magnet 501b on the AA ′ line shown in FIG. 25, the magnetic flux MF3 extending from the north pole of the outer front magnet 501b to the south pole which is the front magnetic pole of the center side front magnet 501b, A magnetic flux MF4 extending from the N pole that is the magnetic pole on the support plate 51 side of the front magnet 501b to the S pole that is the front magnetic pole is coupled. In addition, since the support plate 51 has an S pole, the magnetic flux MF2 extends from the peripheral portion of the support plate 51 to the S pole, which is the front magnetic pole of the outer front magnet 501b, and at the support plate 51 side of the front magnet. A magnetic flux MF4 extending from the north pole to the south pole of the front pole is formed.

By the action of these magnetic fluxes MF3-MF4 and MF2-MF4, an annular horizontal magnetic field H is formed in the lower region of the outer front magnet 501b whose front pole is N-pole as shown on the AA 'line in FIG. The
On the other hand, since the support plate 51 has the south pole, a divergent magnetic flux MF5 is formed in the center-side table magnet 501b, so that the center-side table magnet 501b located on the line AA ′ in FIG. The horizontal magnetic field H is not formed in the lower region.

Also in the other front magnet 501b, an annular horizontal magnetic field H is formed in a lower region of the front magnet 501b whose front magnetic pole is N pole, and this horizontal region is formed in a lower region of the front magnet 501b whose front magnetic pole is S pole. The magnetic field H is not formed.
As a result, as shown in FIG. 25, it is possible to disperse the horizontal magnetic field H in the plane of the support plate 51 at a position different from the position of FIG.

  As described above, the electromagnetic coil 503 is used to rotate the support plate 51 while periodically changing the position of the horizontal magnetic field H formed in a distributed manner in the plane of the support plate 51. The generation region of the plasma P viewed on average becomes more uniform. As a result, the in-plane uniformity during film formation and the effect of contributing to efficient use of the target 31 can be further improved.

Further, by appropriately adjusting the shape, number of arrangement, arrangement position, selection of the polarity of the front magnetic pole, and the like of the front magnet 501b and the back magnet 502, the plasma generation position can be adjusted more precisely.
In addition, in the second and fifth embodiments, the example in which the electromagnetic coil 503 is provided on one of the front magnet 501 and the back magnet 502 to reverse the magnetic pole has been described. Of course, the magnetic poles may be reversed by providing electromagnetic coils 503 on both of the magnets 502.

[Sixth embodiment]
26 to 29 show that the shape of the target 31, the support plate 51, and the front magnet 501c viewed from the lower surface side is rectangular in order to process a rectangular substrate, and the front magnet 501c is arranged in the horizontal direction. 1 is different from the magnetron sputtering apparatus according to the first embodiment shown in FIG. 1 in that a moving mechanism 56a is provided.

  As shown in FIG. 28, the support plate 51 of this embodiment is configured as a rectangular plate corresponding to the shape and dimensions of the target 31, and a support shaft 55c that supports the front magnet 501c is moved to the center of the plate surface. The groove part 511 which comprises the track | orbit to make is provided along the long side direction of a plate surface.

  The front magnet 501c formed in a rectangular parallelepiped shape has a rectangular shape with rounded corners when viewed from the lower surface side, and the long side of the support plate 51 extends along the short side of the support plate 51. It is arranged in the direction crossing the long side. The dimension of the long side of the table magnet 501c is slightly shorter than the short side of the target 31 (shown by a broken line in FIG. 28), while the dimension of the short side of the table magnet 501c is the long side of the target 31. It is set to a fraction of that.

The front magnet 501c of this example is arranged so that the front magnetic pole is the S pole and the magnetic pole on the support plate 51 side is the N pole.
Further, the front magnet 501c is supported by the support bar 55a suspended at the center on the upper surface side, and the upper end of the support bar 55a is linearly movable on the rail 54 arranged along the long side direction of the support plate 51. It is connected to the moving mechanism 56a configured as described above (FIGS. 26 and 27).

  As shown in FIG. 29, a total of twelve rectangular parallelepiped back magnets 502 b are arranged on the upper surface side of the support plate 51. The back magnet 502b is arranged in four regions, with three magnets as a set, with the groove 511 and the central region in the long side direction of the support plate 51 interposed therebetween. Further, the back magnet 502b of this example is arranged so that all the front magnetic poles are S poles.

  In the magnet unit described above, since the magnetic poles on the support plate 51 side of the front magnet 501a and the back magnet 502 are all N poles, the support plate 51 has N poles. As a result, as shown in FIG. 26, a magnetic flux MF2 extending from the support plate 51 to the S pole, which is the front magnetic pole of the front magnet 501, is formed, and an annular horizontal magnetic field H is formed around the lower side of the front magnet 501c by this magnetic flux. (FIG. 28). Similarly to the above-described embodiments, in the front magnet 501c of this example, the magnetic flux MF4 extending from the N pole as the magnetic pole on the support plate 51 side to the S pole as the front magnetic pole is formed, and the magnetic fluxes MF4-MF2 are formed. The horizontal magnetic field H is also formed by the coupling, but for convenience of illustration, the magnetic flux MF2 is not shown in FIGS.

  As shown in FIG. 28, the horizontal magnetic field H formed in the vicinity of the front magnet 501c has two horizontal magnetic fields H extending along the short side direction of the target 31 and two horizontal magnetic fields H extending in the long side direction of the target 31. A horizontal magnetic field H. Therefore, as shown in FIGS. 26 and 27, the horizontal magnetic field H extending along the short side direction is made to cross the horizontal magnetic field H by moving the front magnet 501c periodically in the horizontal direction (that is, It is possible to scan in the long side direction of the target 31. As a result, the plasma P generated by these horizontal magnetic fields H can scan the entire surface of the target 31 to obtain erosion with high in-plane uniformity.

  30 and 31 are examples in which a plurality of front magnets 501c are provided and these front magnets 501c are moved by the moving mechanism 56a. By using a plurality of front magnets 501c, a high deposition rate can be obtained. In addition, when one front magnet 501c is moved, a region where the scanning ranges of the two horizontal magnetic fields H extending along the short side direction of the target 31 overlap and a region which does not overlap are formed. More uniform erosion can be obtained by moving another front magnet 501c so as to compensate for the non-performing region.

  The plurality of table magnets 501c may be moved so that their movement directions and distances coincide with each other by synchronizing the operation of the movement mechanism 56a, and an area shared by each table magnet 501c is set, The moving mechanism 56a may be moved independently.

  In each of the embodiments described above, the configuration of the magnetron sputtering apparatus can be changed as appropriate. For example, the installation of the chamber shield member 44 and the holder shield member 45 may be omitted as necessary, or the type of gas species for generating plasma may be changed.

S Semiconductor wafer 2 Vacuum container 24 Vacuum pump 3 Target electrode 31 Target 4 Placement part 41 High frequency power supply part 51 Support plates 501, 501a to 501c
Table magnet 502, 502a, 502b
Back magnet

Claims (6)

In a magnetron sputtering apparatus in which a target is disposed so as to face a substrate to be processed placed in a vacuum vessel, and a magnet is provided on the back side of the target,
A power supply for applying a voltage to the target;
A base body made of a magnetically permeable material provided on the back side of the target;
A plurality of first magnets provided on a target side surface of the base body;
A second magnet provided on a surface of the base body opposite to the target,
The first magnet and the second magnet are disposed so as to form an annular horizontal magnetic field in the vicinity of the surface of the target on the substrate side ;
Each of the first magnet and the second magnet has different magnetic poles magnetized at a portion on the base body side and a portion on the opposite side of the base body,
The second magnet includes a plurality of magnets spaced from each other at a central portion of the base body and both side portions of the central portion, and the magnetic flux of the magnet located at the central portion diverges. And a magnetron sputtering apparatus. The base body is magnetized to the polarity of the magnetic pole on the base body side of the second magnet, and a magnetic flux is formed between the base body and the magnetic pole on the opposite side of the base body of the first magnet. The magnetron sputtering apparatus according to claim 1, wherein At least one of the first magnet and the second magnet is configured as an electromagnet, and the magnetic pole in the portion on the base body side and the magnetic pole in the portion on the opposite side of the base body are inverted according to the direction of the current of the electromagnetic coil. 3. The magnetron sputtering apparatus according to claim 1 , wherein the magnetron sputtering apparatus is configured as described above. Magnetron sputtering apparatus according to any one of claims 1 to 3, characterized in that it comprises a moving mechanism for moving the base body along the surface of the base body. The magnetron sputtering apparatus according to claim 4 , wherein the moving mechanism is a rotating mechanism for rotating the base body along a surface of the base body. The magnetron sputtering apparatus according to claim 4 , wherein the moving mechanism is a mechanism for linearly moving the base body along the surface of the base body.

Images