JP2003239074A - Wafer supporting device, and metal film manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct temperature control uniformly over the entire surface of a substrate 3 with high accuracy. <P>SOLUTION: He gas of high heat transfer rate is controlled (maintained) at a predetermined temperature by a temperature regulator 34, and fed between the substrate 3 and an electrostatic chuck 25. The heat of a supporting base 2 which is temperature-regulated by a temperature control unit 6 is uniformly transferred to the substrate 3 with high accuracy, and the temperature is controlled uniformly over the entire surface of the substrate 3 with high accuracy. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer supporting device for supporting a wafer (substrate) for manufacturing a semiconductor and a metal film forming device for forming a metal film on the substrate.

[0002]

2. Description of the Related Art Currently, in manufacturing semiconductors, plasma CV is used.
Film formation using a D (Chemical Vapor Deposition) apparatus is known. A plasma CVD apparatus is an apparatus for introducing a material gas, which is a material for a film, into a film forming chamber to bring it into a plasma state, and promoting a chemical reaction on a substrate surface by active excited atoms in the plasma to form a film. Is. The plasma CVD apparatus includes a wafer supporting device having a substrate supporting portion (supporting base) for supporting the substrate in the film forming chamber.

It is known that the plasma CVD apparatus is provided with a temperature control means in the wafer supporting apparatus and the temperature of the substrate is controlled to a predetermined temperature by heat transfer with the mounting surface of the substrate. Generally, a support base of a wafer support device is provided with an electrostatic chuck that attracts a substrate by an electrostatic force, and the adhesion between the substrate and the support base is improved to properly perform heat transfer. As a result, it is possible to efficiently control the temperature of the substrate.

[0004]

However, since the substrates have different deformations such as warpage, it is very difficult to uniformly contact the entire surface of the substrate with the mounting surface of the support. For this reason, there is a limit to the accuracy in controlling the temperature so that the temperature of the entire surface of all the substrates becomes uniform by heat transfer by contact. It may be possible to provide a temperature sensor or the like to adjust the temperature on the support base side for each substrate to increase the uniformity and control the substrate to a predetermined temperature, but this is not practical because of the high cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wafer supporting apparatus and a wafer supporting method which improve the heat transfer efficiency between the wafer and the mounting surface of the supporting table without increasing the cost. And

Further, the present invention has been made in view of the above circumstances, and a metal film forming apparatus equipped with a wafer supporting device which improves the heat transfer efficiency between the wafer and the mounting surface of the supporting table without increasing the cost, and It is an object to provide a method for producing a metal film.

[0007]

In order to achieve the above object, the structure of a wafer supporting apparatus of the present invention comprises a support table on which a wafer is placed, and a noble gas is placed on the wafer placing surface. And a rare gas supply system for supplying the rare gas.

The rare gas supply system is provided with temperature adjusting means for adjusting the temperature of the rare gas to a predetermined temperature. Further, the temperature adjusting means is a temperature adjuster that is provided in a rare gas supply system outside the support table and directly adjusts the temperature of the rare gas. Further, the support base is provided with temperature control means for controlling the temperature of the wafer to be mounted to a predetermined temperature by heat transfer, and the temperature adjusting means is a rare gas passage formed in the support base. The circulating rare gas is adjusted to a predetermined temperature by the temperature control means.

Further, the rare gas supply system is characterized in that a plurality of supply ports for supplying the rare gas are provided on the wafer mounting surface of the support table. The rare gas is helium.

The metal film forming apparatus of the present invention for achieving the above object is arranged in a film forming chamber provided with a member to be etched made of metal, according to any one of claims 1 to 6. Wafer supporting apparatus described above, source gas supply means for supplying source gas containing halogen, and precursor of metal component and source gas contained in the member to be etched by generating source gas plasma to etch the member to be etched It is characterized in that it is provided with a plasma generating means for generating a body and a temperature control means for lowering the temperature on the side of the wafer to be lower than the temperature on the side of the member to be etched to form a metal component of the precursor on the wafer.

The source gas containing halogen is
It is characterized by being a raw material gas containing chlorine. In addition, when the member to be etched is made of copper, CuxCly is generated as a precursor.

The wafer supporting method of the present invention for achieving the above object is characterized in that a rare gas is supplied between the wafer and the wafer to support the wafer on the mounting surface of the support base.

The temperature of the rare gas is adjusted to a predetermined temperature. Further, it is characterized in that the temperature of the rare gas is directly adjusted outside the support table. Further, the support base is provided with a temperature control means, and the temperature control means of the support base adjusts the rare gas to a predetermined temperature inside the support base.

Further, it is characterized in that a rare gas is supplied from a plurality of locations to the wafer. The rare gas is helium.

A method for producing a metal film according to the present invention for achieving the above object, comprises a wafer supported by the supporting method according to any one of claims 10 to 15 and a member to be etched made of metal. A source gas containing halogen is supplied into the chamber, plasma is generated in the chamber to generate source gas plasma, and the member to be etched is etched by the source gas plasma. Is produced, and the temperature on the wafer side is made lower than the temperature on the member to be etched to deposit the metal component of the precursor on the wafer.

The source gas containing halogen is
It is characterized by being a raw material gas containing chlorine. In addition, when the member to be etched is made of copper, CuxCly is generated as a precursor.

[0017]

1 is a schematic side view showing an example of a metal film forming apparatus having a wafer supporting apparatus according to a first embodiment of the present invention, and FIG. 2 is a schematic configuration of the wafer supporting apparatus. There is.

As shown in FIG. 1, it is formed in a cylindrical shape,
For example, a chamber 1 made of ceramics (made of an insulating material)
A support base 2 is provided near the bottom of the (insulating material), and a wafer (substrate) 3 is attached to the support base 2 via an electrostatic chuck 25.
Is placed by suction. That is, the support base 2 and the electrostatic chuck 25 constitute a wafer support device. As the wafer supporting device, a mechanical pressing mechanism (spring or the like) is used.
Accordingly, a configuration in which the substrate 3 is positioned and mounted on the support base 2 only by mounting and fixing the substrate 3 on the support base 2 or by mounting a positioning member on the mounting surface and mounting the same.

A heater 4 and a refrigerant circulating means 5 are provided on the support base 2.
Is provided, and the support base 2 is controlled by the temperature control means 6 to a predetermined temperature (for example, the temperature at which the substrate 3 is maintained at 100 ° C. to 200 ° C.). The upper surface of the chamber 1 is an opening, and the opening is closed with a copper plate member 7 as a member to be etched made of metal. A vacuum device 8 is provided inside the chamber 1 closed by the copper plate member 7.
Is maintained at a predetermined pressure (P1).

A coil-shaped plasma antenna 9 is provided around the cylindrical portion of the chamber 1, and a matching device 10 and a power source 11 are connected to the plasma antenna 9 to supply power.
The plasma antenna 9, the matching unit 10 and the power supply 11 constitute plasma generating means.

In the cylindrical portion of the chamber 1 above the support table 2, a source gas containing chlorine as a halogen (He, Ar, etc., having a chlorine concentration of ≦ 50%, preferably about 10%) is provided inside the chamber 1. Nozzle 1 for supplying diluted Cl ₂ gas)
2 is connected. The nozzle 12 opens toward the copper plate member 7, and the raw material gas is sent to the nozzle 12 via the flow rate controller 13. (Source gas supply means). The halogen contained in the raw material gas includes fluorine (F) and bromine (B).
It is possible to apply r) and iodine (I).

In the above-mentioned metal film production apparatus, the chamber 1
The raw material gas is supplied from the nozzle 12 to the inside of the chamber, and the electromagnetic wave is made incident on the inside of the chamber 1 from the plasma antenna 9, whereby the Cl ₂ gas is ionized and Cl ₂ gas plasma (raw material gas plasma) 14 is generated. Cl ₂ gas plasma 14
Thereby, an etching reaction occurs in the copper plate member 7, and a precursor (CuxCly) 15 is generated. At this time, the copper plate member 7
The Cl ₂ gas plasma 14 maintains a predetermined temperature (for example, 200 ° C. to 400 ° C.) higher than the temperature of the substrate 3.

Precursor (Cu
The xCly) 15 is carried to the substrate 3 whose temperature is controlled to be lower than that of the copper plate member 7. Precursor delivered to substrate 3 (CuxCly)
15 is applied to the substrate 3 and only Cu ions are generated by the reduction reaction to form a Cu thin film on the surface of the substrate 3.

The reaction at this time can be represented by the following equation. 2Cu + Cl ₂ → 2CuCl → 2Cu ↓ + Cl ₂ ↑ Exhaust port 1 for gases and etching products not involved in the reaction
Exhausted from 7.

Although Cl ₂ gas diluted with He, Ar or the like has been described as an example of the raw material gas, Cl ₂ gas may be used alone or HCl gas may be applied. HCl
When gas is applied, HCl gas plasma is generated as the source gas plasma, but the precursor generated by etching the copper plate member 7 is CuxCly. Therefore, the source gas may be any gas containing chlorine, and a mixed gas of HCl gas and Cl ₂ gas can be used. Further, the material of the copper plate member 7 is not limited to copper (Cu), but if it is a halide-forming metal, preferably a chloride-forming metal, Ag, Au, Pt, Ta,
Ti, W, etc. can be used. In this case, the precursor is a halide (chloride) such as Ag, Au, Pt, Ta, Ti, W and the thin film formed on the surface of the substrate 3 is Ag, Au, Pt, Ta, Ti,
W etc.

Since the metal film forming apparatus having the above structure uses the Cl ₂ gas plasma (source gas plasma) 14, the reaction efficiency is greatly improved and the film forming speed is increased. Further, since Cl ₂ gas is used as the source gas, the cost can be significantly reduced. In addition, since the temperature of the substrate 3 is controlled to be lower than that of the copper plate member 7 by using the temperature control means 6, impurities such as chlorine can be reduced in the Cu thin film 16 and a high quality Cu thin film can be obtained. It will be possible to generate.

By the way, the substrate 3 is attracted by the electrostatic chuck 25 and placed on the support base 2, and the heat of the support base 2 whose temperature has been adjusted by the temperature control means 6 is transferred to the substrate 3 by contact, so that the substrate 3 is transferred. It is controlled to a predetermined temperature. Since the heat of the support base 2 is conducted to the substrates 3 having different warp states by contact, it is difficult to uniformly control the temperature of all the substrates 3 over the entire surface of the substrate 3. Therefore, the wafer supporting apparatus of the present embodiment is provided with a He gas supply system 31 as a rare gas supply system for supplying He gas that is a rare gas to the mounting surface of the substrate 3.

The He gas supply system 31 will be described in detail. As shown in FIGS. 1 and 2, the support base 2 has a He gas supply passage 32.
Is provided, and the He gas supply path 32 is opened on the upper surface of the electrostatic chuck 25 (the mounting surface of the substrate 3). He gas supply path 3
2, a flow meter 33 is provided, and a temperature controller 34 as a temperature adjusting means is provided on the upstream side of the flow meter 33. The He gas supplied to the He gas supply path 32 is directly temperature-controlled (for example, heated) by a temperature controller 34, and a flow meter 33 is provided.
Is supplied to a central portion between the substrate 3 and the electrostatic chuck 25 at a predetermined temperature (for example, the temperature at which the substrate 3 is maintained at 100 ° C. to 200 ° C.).

The He gas supplied between the substrate 3 and the electrostatic chuck 25 is collected and discharged to the He gas discharge passage 35 at the outer peripheral portion, and the He gas discharge passage 35 is provided with a discharge device 36. . The discharging condition of the He gas is controlled by the discharging device 36, and the pressure of the He gas supplied from the He gas supply path 32 is adjusted. That is, He supplied from the He gas supply passage 32
The pressure of the gas is adjusted to a pressure (P2) lower than the pressure (P1) inside the chamber 1 so as not to affect the holding of the substrate 3.

In the above-described wafer supporting apparatus, He gas having a high heat transfer coefficient is controlled (maintained) at a predetermined temperature by the temperature controller 34 and supplied between the substrate 3 and the electrostatic chuck 25.
Even if the substrate 3 is warped or the like, the heat of the support base 2 whose temperature is adjusted by the temperature control means 6 is uniformly and accurately transferred to the substrate 3. Therefore, the temperature can be uniformly and accurately controlled over the entire surface of the substrate 3. Further, since the temperature of the supplied He gas is directly controlled by the temperature controller 34, the substrate 3 can be accurately controlled to a desired temperature, and cooling by the He gas itself can be suppressed to perform complicated control. It is possible to maintain the temperature of He gas at a predetermined temperature with a simple configuration without performing.

He gas may be supplied without providing the temperature controller 34, and in this case also, the heat of the support base 2 is uniformly transferred to the substrate 3 via the He gas having a high heat transfer coefficient. . Also,
Since the substrate 3 is supported by the support base 2 in a state where the entire surface of the substrate 3 is substantially in contact with the electrostatic chuck 25 (in a state where the heat transfer efficiency is high to some extent), a rare gas having a low heat transfer efficiency but an inexpensive gas, For example, Ar or the like (neon, nitrogen, etc.) can be applied. In this case, the heat of the support base 2 can be uniformly transferred to the substrate 3 at low cost. Also,
If the substrate 3 can be maintained at 100 ° C. to 200 ° C. only by controlling the temperature of He gas by the temperature controller 34, the temperature control means 6
Can be omitted.

Another embodiment of the wafer supporting apparatus will be described with reference to FIG. FIG. 3 shows a schematic structure of a wafer supporting apparatus according to the second embodiment of the present invention. The same members as those shown in FIGS. 1 and 2 are designated by the same reference numerals, and duplicate explanations are omitted.

As shown in FIG.
Further, the temperature control means 6 including the refrigerant circulation means 5 is provided, the He gas supply path 32 is provided on the support base 27, and the He gas supply path 32 is provided on the upper surface of the electrostatic chuck 25 (the mounting surface of the substrate 3). It opens at the central part. The He gas supply path 32 is provided with a heat exchange path 28 at a portion of the support 27, and the He gas is supplied to the He gas supply path 32 via a flow meter 33.
The He gas supplied to the He gas supply path 32 is transferred to the heat exchange path 28.
The support base 2 whose temperature is controlled to a predetermined temperature by the temperature control means 6
The heat is exchanged between the electrostatic chuck 25 and the substrate 3 and the temperature is controlled to a predetermined temperature.

Therefore, the He gas adjusted to a predetermined temperature is supplied to the electrostatic chuck 25 with a simple and low-cost structure in which the heat exchange passage 28 is formed in the support 27 without separately providing a temperature adjusting means. It becomes possible to supply between the upper surface and the substrate 3. Therefore, the heat of the support base 2 can be uniformly transferred to the substrate 3 at low cost, and uniform temperature control over the entire surface of the substrate 3 becomes possible.

Another embodiment of the wafer supporting apparatus will be described with reference to FIGS. FIG. 4 is a schematic configuration of a wafer supporting apparatus according to the third embodiment of the present invention, and FIG.
FIG. 6 is a graph showing the relationship between the holding force of the electrostatic chuck, the temperature adjustment efficiency, and the ratio of the supply holes, as viewed from the direction of the VV line in the drawing. The same members as those shown in FIGS. 1 and 2 are designated by the same reference numerals, and duplicate explanations are omitted.

As shown in FIGS. 4 and 5, the support base 37 is provided with the temperature control means 6 including the heater 4 and the refrigerant flow means 5, and the support base 37 is formed with the gas chamber 38. The He gas supply path 32 is connected to a gas chamber 38, and from the gas chamber 38, supply holes 39, which are a plurality of supply ports opening to the upper surface of the electrostatic chuck 25 (the mounting surface of the substrate 3), are provided. As shown in FIG. 5, the supply holes 39 are, for example, evenly provided in a radial state. still,
It is possible to provide a plurality of supply holes 39 concentrically, or to provide a plurality of supply holes 39 at random.

Through the flow meter 33 in the He gas supply path 32
He gas is supplied. He supplied to the He gas supply path 32
The gas is heat-exchanged with the support base 27 whose temperature is controlled to a predetermined temperature by the temperature control means 6 in the gas chamber 38 and is controlled to a predetermined temperature, and the electrostatic chuck 2 is supplied from the plurality of supply holes 39.
5 and the substrate 3.

Therefore, it becomes possible to supply the temperature-controlled He gas in a uniform state between the upper surface of the electrostatic chuck 25 and the substrate 3 without separately providing temperature adjusting means. Therefore, the heat of the support base 2 can be evenly transferred to the substrate 3 at low cost, and the temperature of the entire surface of the substrate 3 can be accurately and uniformly controlled.

As shown in FIG. 6, the smaller the ratio of the total area of the supply holes 39 to the size of the substrate 3 (supply hole ratio), the stronger the holding force of the electrostatic chuck 25.
Further, the larger the ratio of the supply holes, the more efficiently the heat of the support base 37 can be transferred to the substrate 3 (higher temperature control efficiency). For example, when the supply hole ratio is about 80%, the holding force has a minimum limit F, and when the supply hole ratio is about 5%, the temperature control efficiency has a minimum ratio T. When the supply hole ratio is less than 5%, for example, the holding force of the electrostatic chuck 25 becomes weak and the substrate 3 cannot be held, and when the supply hole ratio exceeds 80%, He gas is supplied. Without this, temperature control efficiency becomes low.

Therefore, it is preferable that the supply hole ratio is, for example, about 5% to 80%. Further, more preferably, for example, by setting the supply hole ratio to about 20% around 50%, it is possible to achieve both retention force and temperature control efficiency at the same time.

The wafer supporting device shown in FIGS. 2 and 3 may be provided with the supply hole 39.

[0042]

Since the wafer supporting apparatus of the present invention includes the support table on which the wafer is mounted on the mounting surface and the rare gas supply system for supplying the rare gas to the mounting surface of the wafer, By supplying the rare gas to the mounting surface, the heat transfer efficiency between the mounting surface and the wafer can be improved without increasing the cost. As a result, it becomes possible to uniformly control the temperature of the wafer.

Since the rare gas supply system is provided with the temperature adjusting means for adjusting the temperature of the rare gas to a predetermined temperature, the temperature of the wafer can be uniformly and accurately controlled.

Further, since the temperature adjusting means is a temperature adjusting device which is provided in the rare gas supply system outside the support table and directly adjusts the temperature of the rare gas, the temperature of the wafer is controlled uniformly and accurately to the desired temperature. It will be possible.

Further, the support base is provided with temperature control means for controlling the temperature of the wafer to be mounted to a predetermined temperature by heat transfer, and the temperature adjusting means is a rare gas passage formed in the support base and is a rare gas passage. Since the rare gas flowing through the gas passage is adjusted to a predetermined temperature by the temperature control means, it is possible to uniformly transfer the heat of the support table to the wafer with a simple and low-cost configuration without adding equipment. Uniform temperature control becomes possible over the entire surface of the wafer.

Since the rare gas supply system is provided with a plurality of supply ports for supplying the rare gas to the wafer mounting surface of the supporting table, the heat of the supporting table can be uniformly transferred to the wafer at low cost. Therefore, uniform temperature control can be performed over the entire surface of the wafer.

The metal film forming apparatus of the present invention is arranged in a film forming chamber provided with a metal member to be etched, and the wafer supporting apparatus according to any one of claims 1 to 6,
Raw material gas supplying means for supplying a raw material gas containing halogen, and plasma generating means for generating a precursor of a metal component and a raw material gas contained in the member to be etched by generating a raw material gas plasma to etch the member to be etched And a temperature control unit for lowering the temperature of the wafer side to be lower than the temperature of the member to be etched to form the metal component of the precursor on the wafer. As a result, it is possible to form a high-quality metal thin film having a high film forming speed, low cost and few impurities.

According to the wafer supporting method of the present invention, since the rare gas is supplied between the wafer and the wafer to support the wafer on the mounting surface of the supporting table, the mounting surface and the wafer are not costly. The heat transfer efficiency can be improved. As a result,
It becomes possible to uniformly control the temperature of the wafer.

Since the temperature of the rare gas is adjusted to the predetermined temperature, it becomes possible to control the temperature of the wafer uniformly and accurately.

Further, since the temperature of the rare gas is directly adjusted outside the supporting table, the temperature of the wafer can be uniformly and accurately controlled to a desired temperature.

Further, since the support base is provided with temperature control means, and the temperature control means of the support base adjusts the rare gas to a predetermined temperature inside the support base, it is simple without adding any equipment. With a low-cost structure, the heat of the support table can be uniformly transferred to the wafer, and uniform temperature control can be performed over the entire surface of the wafer.

Further, since the rare gas is supplied from a plurality of locations to the wafer, the heat of the support can be evenly transferred to the wafer at a low cost, and uniform temperature control can be achieved over the entire surface of the wafer. It will be possible.

In the method for producing a metal film of the present invention, halogen is contained in the chamber between the wafer supported by the supporting method according to any one of claims 10 to 15 and the metallic member to be etched. A raw material gas is supplied, a plasma is generated inside the chamber to generate a raw material gas plasma, and a member to be etched is etched by the raw material gas plasma to generate a precursor of a metal component and a raw material gas contained in the member to be etched, By making the temperature of the wafer lower than the temperature of the member to be etched to deposit the metal component of the precursor on the wafer, the deposition rate for the wafer can be controlled uniformly. It is possible to produce a high-quality metal thin film that is fast, low-cost, and has few impurities.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of a metal film manufacturing apparatus including a wafer supporting apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a wafer supporting device.

FIG. 3 is a schematic configuration diagram of a wafer supporting apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a wafer support device according to a third embodiment of the present invention.

5 is a view taken along the line V-V in FIG.

FIG. 6 is a graph showing the relationship between the holding force of an electrostatic chuck, the temperature adjustment efficiency, and the ratio of supply holes.

[Explanation of symbols]

1 Chamber 2, 27, 37 Support 3 Wafer (Substrate) 4 Heater 5 Refrigerant Flow Means 6 Temperature Control Means 7 Copper Plate Member 8 Vacuum Device 9 Plasma Antenna 10 Matching Device 11 Power Supply 12 Nozzle 13 Flow Rate Controller 14 Cl ₂ Gas Plasma 15 Precursor 25 Electrostatic chuck 28 Heat exchange path 31 He gas supply system 32 He gas supply path 33 Flow meter 34 Temperature controller 35 He gas discharge path 38 Gas chamber 39 Supply hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Sakamoto             1-8 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa               Mitsubishi Heavy Industries, Ltd. Basic Technology Research Center F-term (reference) 4K030 AA02 BA01 CA17 EA01 FA01                       GA02 JA10 KA24 KA26 KA30                       KA41

Claims (18)

[Claims] 1. A wafer supporting apparatus comprising: a support table on which a wafer is mounted on a mounting surface, and a rare gas supply system for supplying a rare gas to the mounting surface of the wafer. 2. The wafer supporting apparatus according to claim 1, wherein the rare gas supply system is provided with temperature adjusting means for adjusting the temperature of the rare gas to a predetermined temperature. 3. The wafer supporting apparatus according to claim 2, wherein the temperature adjusting means is a temperature adjuster provided in a rare gas supply system outside the support table to directly adjust the temperature of the rare gas. 4. The temperature control means for controlling the temperature of a wafer to be mounted on the support table to a predetermined temperature by heat transfer according to claim 2, and the temperature adjusting means is a rare gas formed on the support table. A wafer supporting device, wherein a rare gas which is a passage and is circulated in the rare gas passage is adjusted to a predetermined temperature by a temperature control means. 5. The rare gas supply system according to claim 1, wherein the rare gas supply system is provided with a plurality of supply ports for supplying the rare gas to the wafer mounting surface of the support table. Wafer supporting device. 6. The wafer supporting apparatus according to claim 1, wherein the rare gas is helium. 7. The wafer supporting apparatus according to claim 1, which is arranged in a film forming chamber provided with a member to be etched made of metal, and a source gas containing halogen is supplied. Raw material gas supply means, plasma generating means for generating raw material gas plasma to etch a member to be etched to generate a precursor of a metal component and a source gas contained in the member to be etched, and a temperature on the wafer side to be etched. An apparatus for producing a metal film, comprising: temperature control means for forming a metal component of a precursor on a wafer at a temperature lower than the temperature on the member side. 8. The apparatus for producing a metal film according to claim 7, wherein the source gas containing halogen is a source gas containing chlorine. 9. The metal film forming apparatus according to claim 8, wherein the member to be etched is made of copper to generate CuxCly as a precursor. 10. A method of supporting a wafer, characterized in that a rare gas is supplied between the wafer and the wafer to support the wafer on a mounting surface of a support table. 11. The wafer supporting method according to claim 10, wherein the temperature of the rare gas is adjusted to a predetermined temperature. 12. The wafer supporting method according to claim 11, wherein the temperature of the rare gas is directly adjusted outside the support table. 13. The wafer supporting method according to claim 11, wherein the support table is provided with temperature control means, and the rare gas is adjusted to a predetermined temperature inside the support table by the temperature control means of the support table. 14. The wafer supporting method according to claim 10, wherein a rare gas is supplied from a plurality of locations between the wafer and the wafer. 15. The wafer supporting method according to claim 10, wherein the rare gas is helium. 16. A source gas containing halogen is supplied into a chamber between a wafer supported by the supporting method according to claim 10 and a member to be etched made of metal, and the chamber is supplied. To generate a precursor of a metal component contained in the member to be etched and the source gas by etching the member to be etched with the source gas plasma by plasmaizing the inside of the source gas plasma,
A method for producing a metal film, comprising forming a precursor metal component on a wafer by lowering a temperature on a wafer side than a temperature on a member to be etched. 17. The method for producing a metal film according to claim 16, wherein the halogen-containing source gas is a chlorine-containing source gas. 18. The method for producing a metal film according to claim 17, wherein the member to be etched is made of copper to generate CuxCly as a precursor.