JP4646066B2 - Vacuum processing equipment - Google Patents

Description

  The present invention relates to a vacuum processing apparatus, and more particularly to a vacuum processing apparatus capable of stably applying a bias voltage to a rotating substrate.

  For example, in sputtering or the like, in a vacuum processing process in which there are a plurality of targets in one vacuum chamber and the substrate is sequentially moved to a position facing each target to form a film, the substrate is used to increase the uniformity in the substrate surface. A film forming process or the like is performed while rotating. As the vacuum processing apparatus, a configuration is used in which a substrate holder is disposed in a vacuum chamber so that the rotation shaft penetrates the wall of the vacuum chamber, and the rotation shaft is hermetically and rotatably held by a magnetic fluid seal. In this way, the substrate can be rotated while maintaining a high vacuum in the vacuum chamber.

  In the production of highly functional elements such as magnetoresistive elements, substrate bias application during vacuum processing is an effective method for enhancing the characteristics and integration of elements, for example, during film formation or etching. By applying a predetermined bias voltage to the substrate and controlling the energy of ions that collide with the substrate, the quality of the film is improved and the precision of microfabrication is improved.

  An example of a conventional vacuum processing apparatus provided with means for applying a bias voltage while rotating the substrate is shown in the schematic cross-sectional view of FIG. As shown in the figure, the substrate holder 3 holding the substrate 36 is disposed inside the vacuum chamber 1 provided with the exhaust device 9. A rotating body 7 having the same rotation axis as that of the substrate holder 3 passes through the bottom wall of the vacuum chamber 1 and can be rotated and hermetically held by a magnetic fluid seal 12 to keep the inside of the vacuum chamber at a high vacuum. The rotating body 7 is connected to a bias power source 17 via a power introduction mechanism 15.

Details of the power introduction mechanism 15 will be described with reference to FIG. 4 (II ′ sectional view of FIG. 3). As shown in the figure, the power introduction mechanism includes a carbon electrode 32 at a sliding portion with the rotating body 7, and presses the carbon electrode 32 against the rotating body with a predetermined force by the conductive plate 33 and the spring member 34. It is configured. The conductive plate 33 is connected to the bias power source 17 via the wiring 35. Accordingly, for example, high-frequency power is supplied from the bias power source 17, and this applies a predetermined bias voltage to the substrate 36 via the wiring 35, the plate material 33, the carbon electrode 32, and the substrate holder 3. Is done.
JP2002-339064

  In recent years, magnetoresistive elements such as TMR and MRAM, and other high-performance elements have been further improved in terms of film homogenization, film thickness uniformity, surface roughness, etc., in order to achieve higher performance and higher integration. For this purpose, more accurate control of the bias voltage and introduction of high power are necessary for the substrate placed on the rotating substrate holder. However, in the case of a bias power introduction mechanism that is performed from the side surface of a rotating structure (rotating body) as in the prior art described above, in order to ensure that the carbon electrode is in contact with the surface of the rotating body that is a curved surface. The contact area with the carbon electrode 32 cannot be increased, and a mechanism for bringing the carbon electrode into contact with the rotating body needs to be disposed on the side surface of the rotating body, which is structurally complicated. In addition, the stability of power supply to the substrate has become a problem due to deterioration and wear of the carbon electrode due to frictional heat. In other words, the bias potential on the substrate surface is biased to prevent uniform and uniform film formation, or charge up occurs on the substrate surface, destroying the device function, and etching cannot increase the etching rate. In some cases, etc. Furthermore, since the carbon electrode is in contact with a rotating body that is a curved surface, the carbon electrode has a structure that is easily worn, and there is a problem that periodic replacement in a short cycle is necessary.

  The above situation is the same not only in the film formation process such as sputtering but also in the process such as dry etching. In this case, since a larger current flows, the power supply becomes more unstable.

  Under such circumstances, an object of the present invention is to develop a power introduction mechanism having a novel structure, and to provide a vacuum processing apparatus capable of stably supplying power via a sliding portion. It is another object of the present invention to provide a vacuum processing apparatus having a long-life power introduction mechanism.

The vacuum processing apparatus of the present invention includes a substrate holder rotatably provided in a vacuum chamber, a rotating mechanism of the rotating body provided on the outer periphery of the rotating body having the same rotation axis as the substrate holder, and electric power. A vacuum processing apparatus that introduces power from an introduction power source to the substrate holder via the rotating body, wherein the power introducing mechanism is attached to the outer periphery of the rotating body. An annular member; and a second annular member connected to the power introduction power source and disposed so that an end surface thereof slides with an end surface of the first annular member; and the first annular member; A refrigerant is supplied between the second annular member and the second annular member .

  Thus, it is set as the structure which contacts the upper surface of what has the bottom face of the annular member in the upper position, and slides between the end surfaces (the upper surface or the bottom face of the annular member) of the two annular members in the vertical direction. Compared to conventional carbon electrodes, the contact area can be greatly increased, and the structure is simple and the contact area is less likely to fluctuate over a long period of time. Supply becomes possible.

Furthermore, it is preferable to supply a refrigerant between the first conductive annular member and the second conductive annular member, and the frictional heat of the sliding portion is absorbed by the refrigerant, and the temperature of the annular member increases ( For example, resistance value change) can be prevented, and more stable power supply can be achieved. Further, the lubricity between the annular members can be improved by a refrigerant (for example, water).
The refrigerant is preferably a substrate cooling refrigerant. Thus, by using the refrigerant for controlling the substrate temperature also for removing the frictional heat, the entire apparatus can be made compact.

At least the end surfaces of the first and second annular members that slide relative to each other are preferably made of a hard material. For example, by using tungsten carbide or chrome, wear due to sliding can be suppressed, and the end surfaces can change over a long period of time. Less power can be supplied.

  As the power introduction power source, a high frequency power source, a DC power source, a pulse power source, or the like can be used. In particular, a high frequency power source is preferably used for applying a bias voltage to the substrate. Can be controlled with high accuracy.

  As described above, since the power is introduced into the rotating body integral with the substrate holder through the annular members that slide with each other, it is possible to sufficiently increase the contact area between the two. It is possible to stably supply power to Therefore, it is possible to construct a sputtering apparatus, an etching apparatus, and other vacuum processing apparatuses suitable for various high-functional elements. Further, since the frictional heat due to sliding is effectively removed by the refrigerant, the sliding member is prevented from being deteriorated and the resistance value is changed, and stable power supply is possible over a long period of time. Further, the present invention is not limited to the application of a bias voltage to the substrate, but can be applied to uses such as supplying a larger current.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a sputtering apparatus showing an example of the vacuum processing apparatus of the present invention. In the vacuum processing apparatus, as shown in the figure, a substrate holder 3 on which a target 2 and a substrate 36 are placed is placed in a vacuum chamber 1 so as to face each other, and the vacuum chamber 1 is connected to an exhaust device 9 via a valve 8. ing. The target 2 is connected to, for example, a DC power source 11 through the matching unit 10.

  On the other hand, the rotating body 7 penetrates the bottom wall of the vacuum chamber 1, and the vacuum chamber member 12 (for example, a magnetic fluid seal) 12 keeps the air tightness inside the vacuum chamber. Below the vacuum seal member 12, a direct drive motor 14 for rotation that controls the rotation of the rotating body 7 by the interaction between a magnet attached to the rotating body 7 and an electromagnet disposed around the outer periphery thereof is disposed. . Furthermore, an encoder 13 for detecting the rotational speed and direction of the rotating body 7 is arranged. The substrate holder 3 has a structure in which an insulating member 5 is disposed between the substrate electrode 4 and the electrode support member 6, and the substrate electrode 4 introduces power via a power introduction rod 20, a power introduction mechanism 15 and a matching unit 18. The high frequency power source (for example, 13.56 MHz) 17 is connected.

  The power introduction mechanism 15 is provided with a supply port and a discharge port for the substrate cooling refrigerant, and communicates with the fluid path 23 of the substrate holder via the supply path 19 and the discharge path 21 of the rotating body 7, respectively. A fluid adjusted to a predetermined temperature circulates between the fluid paths 23 of the substrate holder to control the substrate 36 to the predetermined temperature.

Next, the power introduction mechanism 15 will be described in more detail with reference to the enlarged schematic diagram shown in FIG.
The power introduction mechanism 15 includes a first annular member 30 attached to the rotating body 7 and a second annular member 31 disposed in contact with the end face of the annular member 30. In this embodiment, Two sets of first and second annular members are arranged. Here, as the first and second annular members, for example, members in which tungsten carbide is coated on the surface of a SUS ring having an outer diameter of 58 mm and an inner diameter of 48 mm are used. Accordingly, the high frequency power is supplied from the high frequency power source 17 through the metal outer frame member (for example, made of SUS) 24 to the second annular members 31, 31 ′, and further to the first annular members 30, 30 ′. Further, the electric power is supplied to the substrate electrode 4 through the electric power introduction rod 20. Here, the outer periphery of the rotating body 7 above the power introduction mechanism 15 is insulated from the electrode introduction rod 20 by the insulator 22 and grounded.

  In addition, the outer frame member 24 is provided with a refrigerant supply port 25 and a discharge port 27 and annular fluid passages 26 and 27 respectively communicating with the refrigerant supply port 25 and the discharge port 27. The passage 21 is configured to always communicate with the refrigerant supply port 25 and the discharge port 27, respectively. Further, the outer frame member 24 is configured such that the refrigerant is also sent to the contact portions of the first annular members 30, 30 ′ and the second annular members 31, 31 ′, and the refrigerant leaking between the two is discharged. Drains 29 and 29 'are provided.

  In this way, the high frequency power for bias is supplied via the annular members 30 and 31, 30 'and 31' having a large contact area. Further, since the frictional heat between the annular members is effectively removed by the refrigerant, stable high-frequency power can be continuously supplied.

  In addition, as the first and second annular members, conductive materials having wear resistance such as tungsten carbide and hard chromium and having corrosion resistance against the refrigerant are preferably used. For example, as described above, It is good also as a structure which coat | covers at least the sliding part with these hard materials using metals and alloys, such as SUS. Further, different materials may be used for the first and second annular members.

  Next, a thin film forming method using the sputtering apparatus of FIG. 1 will be described. After placing the substrate 36 on the substrate holder 3, the inside of the vacuum chamber 1 is evacuated to high vacuum by the exhaust device 9. Subsequently, Ar gas at a predetermined flow rate is introduced from a gas supply mechanism (not shown) and the valve 8 is adjusted to set the inside of the vacuum chamber to a predetermined pressure. At this time, the rotary direct drive motor 14 is driven to rotate the rotating body 7, and the substrate 36 is controlled to a predetermined rotational speed (for example, 100 rpm). Moreover, the constant temperature bath 16 is turned on and the cooling water set to a predetermined temperature is circulated between the substrate holder 3 and the substrate 36 is adjusted to a predetermined temperature.

A high frequency power is supplied from the DC power source 11 to the target 2 to generate plasma, and a bias power is supplied from the bias high frequency power source (13.56 MHz) 17 to the power introduction mechanism 15 to start film formation on the substrate. In this way, the high frequency power for bias is supplied to the substrate electrode 4 via the power introducing mechanism 15 and the power introducing rod 20, and a desired bias voltage is uniformly applied to the entire surface of the substrate. In other words, a thin film is formed on the substrate with the energy of ions colliding with the substrate set to a value suitable for the required film quality, so a thin film with high quality and uniform surface roughness is formed. Is done. Further, since the sliding portion of the power introduction mechanism 15 is made of tungsten carbide and supplied with a refrigerant, an electrical change due to sliding heat is prevented and it is difficult to wear. It can be performed.
The bias power source is not limited to a high frequency power source, and a DC power source or the like can also be used.

In the configuration example of FIG. 2, two sets of the first and second annular members are arranged. Needless to say, one set or three or more sets may be used. Further, the combination of the first and second annular members is not limited to one-to-one, and the second annular member may be disposed so as to slide on the upper and lower end faces of the first annular portion. Or vice versa. Furthermore, it goes without saying that the first annular member may be formed integrally with the rotating body. Moreover, although it was set as the structure which combines the annular member and the refrigerant | coolant of a board | substrate, it is good also as a structure which supplies a refrigerant | coolant separately.
The above is the same in the case of dry etching, and the present invention is not limited to the application of a bias voltage to the rotating body, but is used for other purposes of power introduction (for example, power introduction to an electrostatic adsorption power source inside the rotating body) ) Or prevention of charge up of the substrate holder.

It is typical sectional drawing which shows an example of the vacuum processing apparatus of this invention. It is an enlarged view of the electric current introduction mechanism of FIG. It is typical sectional drawing which shows the conventional vacuum processing apparatus. FIG. 4 is an enlarged view of the current introduction mechanism of FIG. 3.

Explanation of symbols

1 vacuum chamber,
2 targets,
3 Substrate holder,
4 substrate electrodes,
5 Insulating material,
6 electrode support members,
7 Rotating body,
8 valves,
9 exhaust system,
10 matcher,
11 DC power supply,
12 Vacuum seal member,
13 Encoder,
14 Direct drive motor for rotation,
15 Electricity introduction mechanism,
16 constant temperature bath,
17 Bias high frequency power supply 18 Matching unit,
19 Supply path,
20 Electricity introduction rod,
21 discharge channel,
22 insulation members,
23 Fluid path of substrate holder,
24 outer frame member,
25 refrigerant supply port,
26, 28 Annular fluid path,
27 discharge port,
29, 29 'drain,
30 first conductive annular member,
31 second conductive annular portion,
32 carbon electrodes,
33 conductive plate material,
34 Spring member,
35 Wiring,
36 substrates,
37 Sealing material,
38,38 'bearing.

Claims (6)

A substrate holder provided rotatably inside the vacuum chamber, a rotating mechanism of the rotating body provided on the outer periphery of the rotating body having the same rotation axis as the substrate holder, and the rotating body from a power introduction power source. A vacuum processing apparatus provided with a power introduction mechanism for introducing power into the substrate holder via,
The power introduction mechanism is connected to the first annular member attached to the outer periphery of the rotating body and the power introduction power source, and is arranged so that the end surface slides with the end surface of the first annular member. A vacuum processing apparatus comprising: two annular members; and a refrigerant is supplied between the first annular member and the second annular member .   The vacuum processing apparatus according to claim 1, wherein at least end surfaces of the first annular member and the second annular member that slide with each other are made of a hard material. The vacuum processing apparatus according to claim 2, wherein the hard material is tungsten carbide or hard chrome. The refrigerant, vacuum processing apparatus according to any one of claims 1 to 3, characterized in that for cooling the substrate. The power supply mechanism, the vacuum processing apparatus according to any one of claims 1 to 4, characterized in that a predetermined bias voltage is applied to the substrate. The power lead for power supply, vacuum processing apparatus according to any one of claims 1 to 5, characterized in that a high frequency DenHara.

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