JP4986350B2 - Magnetron unit of sputtering apparatus and sputtering apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetron unit of a sputtering apparatus and a sputtering apparatus for forming a thin film on a substrate to be processed.
[0002]
[Prior art]
Generally, a magnetron type sputtering apparatus includes a chamber having a target, a support member disposed in the chamber and supporting a wafer, and a magnetron unit provided on the upper side of the target. The magnetron unit has, for example, a magnet assembly that is arranged to face the target and has a plurality of magnets for forming a magnetic field in the vicinity of the target, and a drive motor that rotationally drives the magnet assembly.
[0003]
When film formation processing of a wafer is performed using such a sputtering apparatus, a process gas (for example, argon gas) is supplied into the chamber, and a predetermined voltage is applied between the target and the support member, Generate plasma. Then, argon ions in the plasma collide with the target, particles sputtered from the target (particles to be sputtered) are deposited on the wafer, and a thin film is formed on the wafer surface.
[0004]
[Problems to be solved by the invention]
In the magnetron type sputtering apparatus as described above, the target becomes high temperature due to the influence of plasma, applied voltage, magnetic field, and the like, so that the target is cooled by circulating cooling water. However, even in this case, the center portion of the target is not sufficiently cooled due to the influence of the magnetic field intensity distribution, etc., and erosion proceeds on the back surface of the center portion of the target, and pinhole-like damage may occur. It was.
[0005]
An object of the present invention is to provide a magnetron unit of a sputtering apparatus and a sputtering apparatus that can effectively cool a target.
[0006]
[Means for Solving the Problems]
A magnetron unit of a sputtering apparatus according to the present invention includes a frame that is attached to a target of the sputtering apparatus, and a magnet that is disposed in an inner region of the frame so as to face the target and has a plurality of magnets for forming a magnetic field in the vicinity of the target. An assembly; drive means for rotationally driving the magnet assembly; and coolant supply means for supplying a coolant for cooling the target. The coolant supply means is provided in the frame, and the coolant is supplied to the inner region of the frame. And a discharge port for discharging the cooling liquid from the inner region of the frame. The discharge port is provided on the opposite side of the introduction port in the frame.
[0007]
By providing the coolant discharge port on the opposite side of the introduction port in the frame in this manner, the coolant introduced from the introduction port to the inner region of the frame enters the gap between the target and the magnet assembly and is positioned on the opposite side. It is discharged to the outer area of the frame from the outlet. That is, the coolant is sufficiently circulated in the gap between the target and the magnet assembly. For this reason, even if the temperature at the center of the target tends to increase due to the influence of the intensity distribution of the magnetic field formed by the magnet assembly, the center of the target is sufficiently cooled. Thereby, the cooling efficiency of a target improves.
[0008]
Preferably, the introduction port and the discharge port are provided in the frame so as to face each other across the center of the frame. As a result, the cooling liquid introduced into the inner region of the frame circulates more sufficiently in the gap between the target and the magnet assembly, further improving the cooling efficiency of the target.
[0009]
Preferably, the frame is provided with a coolant supply path extending from a position near the discharge port to the introduction port, or a coolant supply path extending from a position near the introduction port to the discharge port. In this case, both the coolant introduction pipe and the coolant discharge pipe can be arranged on the coolant introduction port side, or can be arranged on the coolant discharge port side. Therefore, even when there is no space for pipe installation on the inlet side or outlet side of the coolant, the coolant can be reliably supplied to the inner region of the frame.
[0010]
At this time, the coolant introduction path preferably has a groove shape. In this case, the coolant introduction path can be easily formed by cutting or the like.
[0011]
Further preferably, the introduction port is provided at the bottom of the frame. Thereby, the coolant introduced into the inner region of the frame from the introduction port can be effectively introduced into the gap between the target and the magnet assembly.
[0012]
Preferably, the plurality of magnets includes a plurality of first magnets arranged in an annular shape so as to be eccentric with respect to the center of the target, and a plurality of second magnets arranged so as to surround the plurality of first magnets. And have. Thereby, a magnetic field can be uniformly formed in the vicinity of the target.
[0013]
The present invention also includes a chamber having a target, a support member disposed in the chamber and supporting a substrate to be processed, a gas supply means for supplying a process gas into the chamber, and a process gas supplied into the chamber. A sputtering apparatus comprising plasma generating means for converting into plasma and a magnetron unit provided on the side opposite to the support member side of the target and confining the plasma generated by the plasma generating means in the vicinity of the target. A frame attached to the target, a magnet assembly disposed in an inner region of the frame so as to face the target, and having a plurality of magnets for forming a magnetic field in the vicinity of the target, and driving means for rotationally driving the magnet assembly And to cool the target A cooling liquid supply means for supplying the cooling liquid, and the cooling liquid supply means is provided in the frame, and is provided on the opposite side of the frame from the inlet for introducing the cooling liquid into the inner region of the frame. And a discharge port for discharging the coolant from the inner region of the frame.
[0014]
In this way, in the magnetron unit, by providing the coolant discharge port on the opposite side of the introduction port in the frame, the coolant introduced from the introduction port to the inner region of the frame enters the gap between the target and the magnet assembly. It goes to the discharge port located on the opposite side, and is discharged from the discharge port to the outer region of the frame. That is, the coolant is sufficiently circulated in the gap between the target and the magnet assembly. For this reason, even if the temperature at the center of the target tends to increase due to the influence of the intensity distribution of the magnetic field formed by the magnet assembly, the center of the target is sufficiently cooled. Thereby, the cooling efficiency of a target improves.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a magnetron unit of a sputtering apparatus and a sputtering apparatus according to the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a diagram schematically showing an embodiment of a sputtering apparatus according to the present invention. In the figure, a sputtering apparatus 1 of this embodiment is a magnetron type sputtering apparatus for forming, for example, a Ti film or a TiN film on the surface of a wafer W.
[0017]
The sputtering apparatus 1 includes a housing 2 and a target 3 disposed so as to close an upper opening of the housing 2, and the housing 4 and the target 3 constitute a chamber 4. A pedestal 5 that supports the wafer W is disposed in the chamber 4, and the pedestal 5 is disposed in parallel to the lower surface of the target 3.
[0018]
An exhaust port 6 and a gas introduction port 7 are formed in the housing 2. A vacuum pump 8 such as a cryopump is connected to the exhaust port 6, and the inside of the chamber 4 is depressurized by operating the vacuum pump 8. A gas supply source 9 is connected to the gas introduction port 7, and argon gas as a process gas is supplied from the gas supply source 9 into the chamber 4 through the gas introduction port 7.
[0019]
The target 3 and the pedestal 5 are connected to the cathode and the anode of the DC power supply 10, respectively. In a state where the wafer W is placed on the pedestal 5, when argon gas is introduced into the chamber 4 and a predetermined voltage is applied between the target 3 and the pedestal 5, the argon gas is turned into plasma.
[0020]
A magnetron unit 11 for confining the plasma generated in the chamber 4 in the vicinity of the target 3 is disposed on the side opposite to the pedestal 5 side of the target 3, that is, on the upper side of the target 3.
[0021]
The magnetron unit 11 has a frame 12 attached to the upper surface of the edge of the target 3. The frame 12 is formed of a plastic having resistance to insulation and has a circular inner wall surface (see FIG. 3). A top plate 13 is attached to the upper surface of the frame 12. A magnet assembly 14 is disposed in the inner region of the frame 12.
[0022]
The magnet assembly 14 includes a base plate 15 and a plurality of magnets 16 that are attached to the lower surface of the base plate 15 and form a magnetic field in the vicinity of the target 3. As shown in FIG. 2, these magnets 16 are composed of a plurality of first magnets 16a arranged in a substantially ring shape and a plurality of second magnets 16b arranged so as to surround these first magnets 16a. Yes. The first magnet 16 a and the second magnet 16 b are arranged in an eccentric state with respect to the center of the target 3 so that a magnetic field is uniformly formed in the vicinity of the target 3. A weight 17 for balancing the weight of the magnet assembly 14 is attached to the lower surface of the base plate 15.
[0023]
A mounting bracket 18 is fixed to the upper surface of the base plate 15, and this mounting bracket 18 is supported by a rotating shaft of a drive motor 19 provided on the top plate 13. Thus, when the drive motor 19 is rotated, the magnet assembly 14 is rotationally driven via the mounting bracket 18.
[0024]
Such a magnetron unit 11 is provided with a cooling water supply system 20 that supplies cooling water for cooling the target 3. The cooling water supply system 20 is provided in the frame 12 and is provided on the opposite side of the introduction port 21 in the frame 12 to the introduction port 21 for introducing the cooling water into the inner region of the frame 12. And a discharge port 22 for discharging from the inner region. The introduction port 21 and the discharge port 22 are formed in the frame 12 so as to face each other with the center of the frame 12 interposed therebetween.
[0025]
The introduction port 21 is preferably formed at the bottom of the frame 12 so that the cooling water introduced into the inner region of the frame 12 can effectively flow into the gap between the magnet assembly 14 and the target 3. On the other hand, the discharge port 22 is formed in the upper part of the frame 12 in order to effectively discharge the cooling water existing in the inner region of the frame 12.
[0026]
As shown in FIGS. 3 and 4, the frame 12 is formed with a groove-like introduction path 23 that communicates with the introduction port 21. The groove-like introduction path 23 extends from the position adjacent to the discharge port 22 along the inner wall surface of the frame 12. Note that the groove-like introduction path 23 can be easily formed by, for example, cutting.
[0027]
A pipe 24 for introducing cooling water is connected to a terminal end 23 a opposite to the inlet 21 in the groove-like introduction path 23 through a through hole (not shown) formed in the top plate 13. In addition, a cooling water discharge pipe 26 is connected to the discharge port 22 through a through hole 25 formed in the top plate 13. Thereby, the cooling water sent by the pipe 24 passes through the groove-like introduction path 23 of the frame 12 and is introduced from the introduction port 21 into the inner region of the frame 12. Then, the cooling water circulating in the inner region of the frame 12 flows out of the frame 12 from the discharge port 22 and is discharged through the pipe 26.
[0028]
In addition, the introduction path for supplying the cooling water to the introduction port 21 in the frame 12 is not particularly limited to the groove shape as described above, and may be a tunnel shape, for example.
[0029]
When film formation is performed by the sputtering apparatus 1 configured as described above, first, the wafer W is loaded into the chamber 4 by a transfer means (not shown) and placed on the pedestal 5. Then, the inside of the chamber 4 is decompressed to a desired degree of vacuum by the vacuum pump 8, and the argon gas from the gas supply source 9 is introduced into the chamber 4. Then, with the magnet assembly 14 rotated by the drive motor 19, the DC power supply 10 is turned on, and a desired voltage is applied between the target 3 and the pedestal 5. Then, a glow discharge is generated in the chamber 4, and argon ions in the plasma collide with the lower surface of the target 3 to eject target atoms (particles to be sputtered), and the target atoms are deposited on the wafer W to form a thin film. It is formed.
[0030]
At this time, the temperature of the target 3 rises due to influences such as generation of plasma in the chamber 4, application of a high voltage between the target 3 and the pedestal 5, and generation of a magnetic field by the magnetron unit 11. For this reason, the cooling water is supplied to the inner region of the frame 12 by the cooling water supply system 20 to cool the target 3.
[0031]
Here, as a comparative example, as shown in FIGS. 5 and 6, when the introduction port 51 and the discharge port 52 are formed adjacent to the frame 50, the following problems occur. That is, in general, the gap between the lower surface of the magnet assembly 14 and the upper surface of the target 3 is as narrow as several millimeters, and the cooling water is difficult to enter the gap. In addition to this, when the introduction port 51 and the discharge port 52 are provided adjacent to each other, the cooling water introduced from the introduction port 51 to the inner region of the frame 50 sufficiently enters the gap between the magnet assembly 14 and the target 3. There is a possibility that it will immediately flow out of the outlet 52. In this case, the cooling of the center portion of the target 3 is particularly insufficient, so that erosion progresses on the back surface of the center portion of the target 3 and pinhole-like damage may occur.
[0032]
On the other hand, in the present embodiment, the cooling water introduction port 21 is provided in the frame 12 at a position facing the discharge port 22, so that the cooling water introduced from the introduction port 21 into the inner region of the frame 12 The air enters the gap with the magnet assembly 14, travels toward the opposite discharge port 22, and is discharged from the discharge port 22 to the outside of the frame 12. At this time, since the cooling water inlet 21 is provided at the bottom of the frame 12, the cooling water easily enters the gap between the target 3 and the magnet assembly 14. For this reason, even when the gap between the target 3 and the magnet assembly 14 is narrow, the cooling water circulates sufficiently in the gap. Therefore, since the center part of the target 3 is also sufficiently cooled, pinhole-like damage occurring on the back surface of the center part of the target 3 is reduced.
[0033]
The present invention is not limited to the above embodiment. For example, in the above embodiment, the cooling water introduction port 21 and the discharge port 22 are formed at positions facing each other across the center of the frame 12, but the introduction port 21 is on the opposite side of the frame 12 from the discharge port 22. If it is formed, it may be formed at a position shifted from the opposing position across the center of the frame 12.
[0034]
In the above embodiment, the cooling water introduction pipe 24 and the cooling water discharge pipe 26 are both arranged on the discharge port 22 side of the frame 12, and the groove-like introduction path 23 communicating with the introduction port 21 is provided in the frame 12. However, if there is no space limitation on the introduction port 21 side of the frame 12, the pipe 24 may be arranged on the introduction port 21 side of the frame 12. In this case, it is not necessary to form the groove-like introduction path 23 in the frame 12.
[0035]
Furthermore, in the said embodiment, although it was set as the structure which forms in the flame | frame 12 the groove-shaped introduction path 23 extended from the vicinity of the discharge port 22 to the introduction port 21, this invention is the pipe | tube 24 and cooling water for cooling water introduction, for example The present invention can also be applied to a case in which both the discharge pipes 26 are arranged on the introduction port 21 side of the frame 12 and a cooling water supply path extending from the vicinity of the introduction port 21 to the discharge port 22 is formed in the frame.
[0036]
【Effect of the invention】
According to the present invention, since the coolant discharge port is provided on the opposite side of the coolant introduction port in the frame, the target can be effectively cooled by the coolant. Thereby, damage to the target caused by the temperature rise of the target can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of an embodiment of a sputtering apparatus according to the present invention.
FIG. 2 is a plan view of the magnet assembly shown in FIG.
3 is a horizontal sectional view of the frame shown in FIG. 1. FIG.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is a horizontal sectional view of a frame as a comparative example.
6 is a cross-sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sputtering device, 3 ... Target, 4 ... Chamber, 5 ... Pedestal (support member), 9 ... Gas supply source (gas supply means), 10 ... DC power supply (plasma generation means), 11 ... Magnetron unit, 12 ... Frame , 14 ... magnet assembly, 16 ... magnet, 16 a ... first magnet, 16 b ... second magnet, 19 ... drive motor (drive means), 20 ... cooling water supply system (coolant supply means), 21 ... introduction port, 22 ... discharge port, 23 ... annular introduction path (coolant introduction path), W ... wafer (substrate to be processed).

Claims (5)

A frame attached to the target of the sputtering apparatus;
A magnet assembly disposed in an inner region of the frame so as to face the target and having a plurality of magnets for forming a magnetic field in the vicinity of the target;
Drive means for rotationally driving the magnet assembly;
A coolant supply means for supplying a coolant for cooling the target,
The cooling liquid supply means is provided in the frame, and is provided in the frame so as to face the introduction port across the center of the frame with an introduction port for introducing the cooling liquid into the inner region of the frame. is, the coolant possess an outlet for discharging from the inner region of the frame, the frame, the cooling liquid supply passage extending from a position near said outlet to said inlet or said inlet A magnetron unit of a sputtering apparatus, wherein a cooling liquid supply path extending from a nearby position to the discharge port is provided . Magnetron unit of the coolant supply passage sputtering apparatus of claim 1, wherein the form a groove. The magnetron unit of the sputtering apparatus according to claim 1, wherein the introduction port is provided at a bottom portion of the frame. The plurality of magnets includes a plurality of first magnets arranged in an annular shape so as to be eccentric with respect to a center of the target, and a plurality of second magnets arranged so as to surround the plurality of first magnets. The magnetron unit of the sputtering apparatus as described in any one of Claims 1-3 which has. A chamber having a target;
A support member disposed in the chamber and supporting a substrate to be processed;
Gas supply means for supplying a process gas into the chamber;
Plasma generating means for converting the process gas supplied into the chamber into plasma;
A sputtering apparatus comprising: a magnetron unit provided on a side opposite to the support member side of the target, and confining the plasma generated by the plasma generating means in the vicinity of the target;
The magnetron unit is
A frame attached to the target;
A magnet assembly disposed in an inner region of the frame so as to face the target and having a plurality of magnets for forming a magnetic field in the vicinity of the target;
Drive means for rotationally driving the magnet assembly;
A coolant supply means for supplying a coolant for cooling the target,
The cooling liquid supply means is provided in the frame, and is provided in the frame so as to face the introduction port across the center of the frame with an introduction port for introducing the cooling liquid into the inner region of the frame. is, the coolant possess an outlet for discharging from the inner region of the frame, the frame, the cooling liquid supply passage extending from a position near said outlet to said inlet or said inlet A sputtering apparatus provided with a coolant supply path extending from a nearby position to the discharge port .

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