JP2006200025A - Surface treatment apparatus, thin-film-forming apparatus, surface treatment method and thin-film-forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-film-forming apparatus which eliminates an effect of Cl atoms and does not form an impurity layer without needing a post-treatment step. <P>SOLUTION: This thin-film-forming method comprises the steps of: stopping the supply of Cl<SB>2</SB>gas 21 after having formed the thin film of Cu, and simultaneously supplying He gas 22 from a gas nozzle 18; turning a bias power supply 31 on to apply a biased power to a substrate 3; introducing He ions into the periphery of the substrate 3 to which the biased power is applied; and thereby applying energy due to ion bombardment onto the substrate 3 while keeping the substrate 3 at a low temperature to remove Cl atoms remaining in the Cu thin film. The thin-film-forming apparatus thus eliminates the effect of Cl atoms and does not form the impurity layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a surface treatment apparatus and a surface treatment method for producing a metal thin film on a surface of a substrate.
The present invention also relates to a thin film production apparatus and a thin film production method for producing a metal thin film on the surface of a substrate.

  Currently, in the manufacture of semiconductors and the like, film formation using a plasma CVD (Chemical Vapor Deposition) apparatus is known. A plasma CVD apparatus is a plasma reaction of a gas such as an organometallic complex that becomes a material of a film introduced into a chamber by a high frequency incident from a high frequency antenna, and a chemical reaction on the substrate surface by active excited atoms in the plasma. Is a device for forming a metal thin film or the like by promoting the above.

  On the other hand, the present inventors installed a member to be etched, which is a metal component that forms a high vapor pressure halide, and is made of a metal component desired to be formed into a film, and the member to be etched is formed by plasma of halogen gas. A plasma CVD apparatus (hereinafter referred to as a new type of plasma CVD apparatus) and a film forming method for forming a precursor which is a halide of a metal component by etching and forming only the metal component of the precursor on a substrate. Developed (for example, see Patent Document 1 below).

JP 2003-147534 A

In the above-described plasma CVD apparatus of the new type, the metal film is formed on the substrate by controlling the temperature of the substrate to be lower than the temperature of the member to be etched which is a metal source to be formed. For example, when the metal of the member to be etched is M and the halogen gas is Cl ₂ , the member to be etched is controlled to a high temperature (for example, 300 ° C. to 700 ° C.) and the substrate is controlled to a low temperature (for example, about 200 ° C.). Thus, an M thin film can be formed on the substrate. This is thought to be due to the following reaction.

(1) Plasma dissociation reaction; Cl ₂ → 2Cl ^*
(2) Etching reaction; M + Cl ^* → MCl (g)
(3) Adsorption reaction to the substrate; MC1 (g) → MC1 (ad)
(4) Film formation reaction; MCl (ad) + Cl ^* → M + Cl ₂ ↑
Here, Cl ^* represents a Cl radical, (g) represents a gas state, and (ad) represents an adsorption state.

In the above-described new CVD apparatus, a metal thin film with few impurities can be produced uniformly and at high speed. In the new type CVD apparatus, after forming the M thin film on the substrate, the plasma is stopped and the substrate on which the M thin film is formed is carried out and a new substrate is carried in. Immediately after the plasma is stopped, Cl ₂ gas remains. Therefore, Cl ^* and metal M react again (salt) and the impurity layer (contamination layer) is formed without the temperature of the substrate being lowered. It was. In addition, the residual Cl ₂ gas generates particulate contaminants (particles) and adheres to the surface of the substrate. For this reason, the substrate on which the M thin film is formed has removed contamination layers and particles in a post-processing step. Accordingly, an apparatus for post-processing is required, and the cost for the post-processing process is high at present.

  Such a problem is also a problem that occurs when a desired thin film is formed on the surface of the substrate by a reducing action by reducing gas plasma.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a surface treatment apparatus and a surface treatment method in which an impurity layer or the like is not formed without the influence of a reducing component.

  In addition, the present invention has been made in view of the above situation, and provides a thin film manufacturing apparatus and a thin film manufacturing method in which an impurity layer or the like is not formed without the influence of a reducing component without undergoing a post-processing step. For the purpose.

In order to achieve the above object, a surface treatment apparatus of the present invention according to claim 1 is provided.
In the surface treatment apparatus in which the surface of the substrate is treated by the reducing action of reducing gas radicals,
Bias applying means for applying a bias to the substrate after processing the surface of the substrate;
And a treatment surface cleaning means for drawing inactive gas ions to the substrate by applying a bias to the substrate by the bias application means and removing impurities on the treatment surface by ion bombardment.

In order to achieve the above object, a thin film production apparatus of the present invention according to claim 2 is provided.
A chamber containing a substrate;
A metal member to be etched provided in a chamber at a position facing the substrate;
A source gas supply means for supplying a source gas containing halogen into the chamber;
Plasma generating means for generating a precursor of a metal component and a source gas contained in the member to be etched by generating a source gas plasma by etching the inside of the chamber and etching the member to be etched with the source gas plasma;
Temperature control means for forming a metal component of the precursor on the substrate by making the temperature on the substrate side lower than the temperature of the member to be etched;
A gas supply means for supplying an inert gas into the chamber after depositing the metal component;
Bias applying means for applying a bias to the substrate after forming the metal component;
The inside of the chamber is turned into plasma to generate an inert gas plasma, the inert gas ions are drawn into the substrate to which the bias is applied by the bias applying means, and the impurity of the source gas component on the processing surface is removed by ion bombardment. It is characterized by comprising the following means.

And this invention which concerns on Claim 3 is
The thin film manufacturing apparatus according to claim 2,
The source gas containing halogen is a source gas containing chlorine.

The present invention according to claim 4 provides
In the thin film production apparatus according to claim 2 or claim 3,
The inert gas supplied from the gas supply means is an inert gas for diluting halogen in the source gas supplied by the source gas supply means.

The surface treatment method of the present invention according to claim 5 for achieving the above object is as follows.
In the surface treatment method in which the surface of the substrate is treated by the reducing action of reducing gas radicals, a bias is applied to the substrate after the surface of the substrate is treated, and ions of the inert gas are drawn into the substrate, and ion bombardment is performed. To remove impurities on the treated surface.

In order to achieve the above object, the thin film manufacturing method of the present invention according to claim 6 comprises:
A source gas containing halogen is supplied into a chamber provided with a substrate and a metal member to be etched,
The inside of the chamber is turned into plasma to generate a source gas plasma, and the member to be etched is etched with the source gas plasma to generate a precursor of the metal component and source gas contained in the member to be etched,
By making the temperature of the substrate side lower than the temperature of the member to be etched, the metal component of the precursor is formed on the substrate,
After depositing the metal component, an inert gas is supplied into the chamber and a bias is applied to the substrate.
The inside of the chamber is converted into plasma to generate an inert gas plasma, and ions of the inert gas are drawn into the substrate, and impurities on the processing surface are removed by ion bombardment.

And this invention which concerns on Claim 7 is
In the thin film preparation method according to claim 6,
The source gas containing halogen is a source gas containing chlorine.

The present invention according to claim 8 provides:
In the thin film production method according to claim 6 or 7,
The inert gas supplied after depositing the metal component is an inert gas for diluting the halogen in the source gas.

  According to the first aspect of the present invention, the reducing gas component remaining in the film can be released by ion bombardment. For this reason, it becomes possible to provide a surface treatment apparatus that eliminates the influence of the reducing component and does not form an impurity layer or the like.

  In the present invention of claim 2, the reducing gas component remaining in the film can be separated by ion bombardment without heating the substrate at the end of film formation. For this reason, a thin film can be formed uniformly and at high speed, and it is possible to provide a thin film manufacturing apparatus in which an impurity layer or the like is not formed without the influence of a reducing component without passing through a post-processing step.

  In the present invention of claim 3, since the gas containing chlorine is applied as the source gas containing the halogen gas, the cost can be reduced by using an inexpensive chlorine gas. In addition, 100% chlorine gas is not used in the process, but it is diluted with an inert gas or the like, so that the cost can be further reduced. In addition, if a rare gas is used as an inert gas for dilution, the highly reactive chlorine gas and the dilution gas do not react with each other, the main reaction can be performed stably, and the rare gas itself The bias effect can also be used.

  In the present invention of claim 4, since the ion bombardment is performed using the inert gas for diluting the halogen, it is not necessary to provide a dedicated gas supply means for applying the ion bombardment, and the cost can be suppressed.

  In the present invention of claim 5, the reducing gas component remaining in the film can be released by ion bombardment. For this reason, it becomes possible to set it as the surface treatment method which eliminates the influence of a reducing component and does not form an impurity layer or the like.

  In the present invention of claim 6, the reducing gas component remaining in the film can be separated by ion bombardment without heating the substrate at the end of film formation. For this reason, a thin film can be formed uniformly and at high speed, and it is possible to provide a thin film manufacturing method in which an impurity layer or the like is not formed without the influence of the reducing component without passing through a post-processing step.

  In the present invention of claim 7, since a gas containing chlorine is applied as a raw material gas containing a halogen gas, an impurity layer is formed by using an inexpensive chlorine gas and eliminating the influence of a reducing component without going through a post-treatment step. It becomes possible to set it as the thin film preparation method in which etc. are not formed.

  In the present invention of claim 8, since the ion bombardment is performed using the inert gas for diluting the halogen, it is not necessary to supply a dedicated inert gas to provide the ion bombardment, and the cost can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic side view of a thin film production apparatus according to an embodiment of the present invention, and FIG.

  As shown in FIG. 1, a support base 2 is provided in the vicinity of the bottom of a cylindrical chamber 1 made of, for example, ceramic (made of an insulating material), and a substrate 3 is placed on the support base 2. . The support table 2 is provided with a temperature control means 6 including a heater 4 and a refrigerant flow means 5, and the support table 2 is set to a predetermined temperature (for example, a temperature at which the substrate 3 is maintained at 100 ° C. to 300 ° C.) by the temperature control means 6. ) Is controlled.

  The upper surface of the chamber 1 is an opening, and the opening is closed by a plate-like ceiling plate 7 made of an insulating material (for example, ceramic). A plasma antenna 8 for converting the inside of the chamber 1 into plasma is provided above the ceiling plate 7, and the plasma antenna 8 is formed in a planar ring shape parallel to the surface of the ceiling plate 7. A matching unit 9 and a power source 10 are connected to the plasma antenna 8 to supply a high frequency. Plasma generating means is constituted by the plasma antenna 8, the matching unit 9 and the power source 10.

  The chamber 1 holds a member to be etched 11 made of Cu as a metal, and the member to be etched 11 is disposed in a discontinuous state between the substrate 3 and the ceiling plate 7 with respect to the electric flow of the plasma antenna 8. . For example, the member to be etched 11 includes a rod-shaped protrusion 12 and a ring part 13, and the ring part 13 is provided so that the protrusion 12 extends toward the center of the chamber 1. As a result, the member to be etched 11 is structurally discontinuous with respect to the circumferential direction, which is the flow direction of electricity of the plasma antenna 8.

  In addition, as a structure which makes it a discontinuous state with respect to the electric flow of the plasma antenna 8, it is also possible to form a to-be-etched member in a grid | lattice form, or a net | network form.

As a raw material gas supply means for supplying a raw material gas 21 containing chlorine as a halogen (Cl ₂ gas obtained by diluting chlorine with He gas, which is an inert gas) 21 around the cylindrical portion of the chamber 1. A plurality of nozzles 14 are connected at equal intervals in the circumferential direction (for example, eight locations: two locations are shown in the figure). A Cl ₂ gas 21 is sent to the nozzle 14 via the flow rate controller 15. Gases that are not involved in film formation are exhausted from the exhaust port 16. The inside of the chamber 1 closed by the ceiling plate 7 is maintained at a predetermined pressure by the vacuum device 17.

  Note that fluorine, bromine, iodine, and the like can be applied as the halogen contained in the source gas.

  On the other hand, a gas nozzle 18 serving as a gas supply means for supplying helium gas (He gas) as an inert gas into the chamber 1 is connected to the cylindrical portion of the chamber 1. A He gas 22 is sent to the gas nozzle 18 via a flow rate controller 19. After film formation, He gas plasma is generated by the plasma generating means, and He ions are drawn into the substrate 3 by applying a bias to the substrate 3 described later (processing surface cleaning means).

  In addition, other inert gas, such as Ar gas, can also be applied to the inert gas supplied from the gas nozzle 18. Further, as a gas supply means, it is possible to supply He gas for diluting chlorine from the nozzle 14 without providing the gas nozzle 18. In this case, the nozzle 14 becomes a source gas supply means and a gas supply means. That is, in FIG. 1, the gas nozzle 18 becomes unnecessary.

  On the other hand, a bias power source 31 is connected to the support base 2, and He ions are attracted to the substrate 3 by turning on the bias power source 31 and applying a bias to the substrate 3. By attracting He ions to the substrate 3 and applying ion bombardment, Cl remaining in the film described later can be released without heating the substrate 3.

In the thin film manufacturing apparatus described above, the Cl ₂ gas 21 is supplied from the nozzle 14 into the chamber 1. By entering electromagnetic waves from the plasma antenna 8 into the chamber 1, the Cl ₂ gas 21 is ionized to generate Cl ₂ gas plasma. The plasma is generated in the region shown by the gas plasma 20. The reaction at this time can be expressed by the following formula.
Cl ₂ → 2Cl ^* (1)
Here, Cl ^* represents a chlorine radical.

When the gas plasma 20 acts on the member to be etched 11 made of Cu, the member to be etched 11 is heated and an etching reaction occurs in Cu. The reaction at this time is represented by the following formula, for example.
Cu (s) + Cl ^* → CuCl (g) (2)
Here, s represents a solid state and g represents a gas state. Formula (2) is a state in which Cu is etched by the gas plasma 20 to be a precursor 23.

The member to be etched 11 is heated by generating the gas plasma 20 (for example, 300 ° C. to 700 ° C.), and the temperature of the substrate 3 is lower than the temperature of the member to be etched 11 by the temperature control means 6 (for example, 100 ° C. to 300 ° C.). As a result, the precursor 23 is adsorbed (deposited) on the substrate 3. The reaction at this time is represented by the following formula, for example.
CuCl (g) → CuCl (ad) (3)

CuCl adsorbed on the substrate 3 is reduced by the chlorine radical Cl ^* to become a Cu component, whereby a Cu thin film is produced. The reaction at this time is represented by the following formula, for example.
CuCl (ad) + Cl ^* → Cu (s) + Cl ₂ ↑ (4)

Furthermore, a part of the gasified CuCl (g) generated in the above formula (2) is reduced by the chlorine radical Cl ^* before being adsorbed to the substrate 3 (see the above formula (3)), and is in a gaseous state. It becomes. The reaction at this time is represented by the following formula, for example.
CuCl (g) + Cl ^* → Cu (g) + Cl ₂ ↑ (5)
Thereafter, the Cu component in the gas state is deposited on the substrate 3 to produce a Cu thin film.

  When a Cu thin film is produced, Cl remains in the film. It is effective to heat the substrate 3 in order to release the remaining Cl. However, in the thin film manufacturing apparatus described above, the precursor 23 is kept at a temperature lower than the temperature of the member 11 to be etched. Adsorbed on the substrate 3. For this reason, it is necessary to remove the remaining Cl without heating the substrate 3. In this embodiment, after the Cu thin film is formed, the remaining Cl is released by the following action.

When the Cu thin film is formed (the state shown in FIG. 2A), the supply of the Cl ₂ gas 21 is stopped, and at the same time, the He gas 22 is supplied from the gas nozzle 18. At this time, plasma is kept generated, the bias power supply 31 is turned on, and a bias is applied to the substrate 3. The He gas supplied from the gas nozzle 18 is converted into He ions, and the He ions are drawn into the substrate 3 to which a bias is applied (the state shown in FIG. 2B). Ions are bombarded by ions being drawn into the substrate 3, and energy is applied to the substrate 3 while keeping the temperature of the substrate 3 low. Thereby, Cl remaining in the Cu thin film can be separated (state shown in FIG. 2B).

  Therefore, a thin film production apparatus capable of producing a Cu thin film uniformly and at a high speed, removing residual Cl without going through a post-processing step, and eliminating the influence of Cl to form an impurity layer or the like. Is possible.

  Note that the thin film manufacturing apparatus to which the above-described surface treatment method is applied is not limited to the thin film manufacturing apparatus in the above-described embodiment, and in some cases, the thin film manufacturing apparatus can be applied to a thin film manufacturing apparatus such as a sputtering apparatus. is there.

  The present invention can be used in the industrial field for producing thin films.

1 is a schematic side view of a thin film manufacturing apparatus according to an embodiment of the present invention. It is state explanatory drawing of the surface of a thin film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chamber 2 Support stand 3 Substrate 4 Heater 5 Refrigerant distribution means 6 Temperature control means 7 Ceiling board 8 Plasma antenna 9 Matching device 10 Power supply 11 Member to be etched 12 Projection part 13 Ring part 14 Nozzle 15 Flow rate controller 16 Exhaust port 17 Vacuum apparatus 18 Gas nozzle 20 Gas plasma 21 Source gas 22 He gas 23 Precursor

Claims (8)

In the surface treatment apparatus in which the surface of the substrate is treated by the reducing action of reducing gas radicals,
Bias applying means for applying a bias to the substrate after processing the surface of the substrate;
A surface treatment apparatus comprising: a treatment surface cleaning means for drawing inactive gas ions into the substrate by applying a bias to the substrate by a bias application means and removing impurities on the treatment surface by ion bombardment. A chamber containing a substrate;
A metal member to be etched provided in a chamber at a position facing the substrate;
A source gas supply means for supplying a source gas containing halogen into the chamber;
Plasma generating means for generating a precursor of a metal component and a source gas contained in the member to be etched by generating a source gas plasma by etching the inside of the chamber and etching the member to be etched with the source gas plasma;
Temperature control means for forming a metal component of the precursor on the substrate by making the temperature on the substrate side lower than the temperature of the member to be etched;
A gas supply means for supplying an inert gas into the chamber after depositing the metal component;
Bias applying means for applying a bias to the substrate after forming the metal component;
The inside of the chamber is turned into plasma to generate an inert gas plasma, the inert gas ions are drawn into the substrate to which the bias is applied by the bias applying means, and the impurity of the source gas component on the processing surface is removed by ion bombardment. And a thin film forming apparatus. The thin film manufacturing apparatus according to claim 2,
A thin film manufacturing apparatus, wherein the halogen-containing source gas is a chlorine-containing source gas. In the thin film production apparatus according to claim 2 or claim 3,
The thin film manufacturing apparatus, wherein the inert gas supplied from the gas supply means is an inert gas for diluting halogen in the source gas supplied by the source gas supply means.   In the surface treatment method in which the surface of the substrate is treated by the reducing action of reducing gas radicals, a bias is applied to the substrate after the surface of the substrate is treated, and ions of the inert gas are drawn into the substrate, and ion bombardment is performed. A surface treatment method characterized by removing impurities on the treated surface. A source gas containing halogen is supplied into a chamber provided with a substrate and a metal member to be etched,
The inside of the chamber is turned into plasma to generate a source gas plasma, and the member to be etched is etched with the source gas plasma to generate a precursor of the metal component and source gas contained in the member to be etched,
By making the temperature of the substrate side lower than the temperature of the member to be etched, the metal component of the precursor is formed on the substrate,
After depositing the metal component, an inert gas is supplied into the chamber and a bias is applied to the substrate.
A method for producing a thin film characterized in that the inside of a chamber is converted into plasma to generate an inert gas plasma, ions of the inert gas are drawn into the substrate, and impurities on the processing surface are removed by ion bombardment. In the thin film preparation method according to claim 6,
A method for producing a thin film, characterized in that the source gas containing halogen is a source gas containing chlorine. In the thin film production method according to claim 6 or 7,
A method for producing a thin film, wherein the inert gas supplied after depositing the metal component is an inert gas for diluting halogen in the source gas.

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