JP4317077B2 - Metal film production equipment - Google Patents

Description

The present invention relates to a metal film production apparatus for producing a refractory metal or a noble metal in a fine hole, for example.

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

By the way, as seen in the following Patent Document 2, capacitors used in FeRAM (Ferroelectric Random Access Memory) are, for example, iridium (Ir), platinum (Pt), etc. on silicon oxide (SiO ₂ ). A substrate on which a noble metal is formed is used, and a ferroelectric is laminated on the substrate on which the noble metal is formed. In recent years, in order to reduce the size and capacity of a capacitor, it has been considered to secure an area for storing electric charges while reducing the size by making the ferroelectric portion a three-dimensional structure. In this case, a fine hole is formed in the substrate, and a noble metal film is formed on the inner wall surface of the hole.

  In the above-described new type CVD apparatus, a metal thin film with few impurities can be produced uniformly and at high speed. Application of this new type of CVD apparatus to form a noble metal such as iridium (Ir) or platinum (Pt) on a substrate has been studied.

JP-A-11-121703

In the above-described new type CVD apparatus, the member to be etched is etched by plasma of halogen gas (Cl ₂ gas) to generate a precursor which is a metal component halide. For this reason, when a noble metal film is formed, for example, Ir is applied as the member to be etched, and IrCl is formed as the precursor. Since Ir is a metal that is unlikely to become a chloride, it was necessary to form IrCl by supplying a large amount of Cl ₂ gas in order to obtain IrCl required for film formation. However, if a large amount of Cl ₂ gas is supplied, Cl ^*, which is a Cl radical, increases, and damage to the substrate, particularly the bottom surface of a fine hole, is caused by Cl ^* . When Ir is deposited in a state where the substrate is damaged, the substrate is corroded by catalytic action, and there is a possibility that a capacitor having necessary characteristics cannot be obtained.

  Therefore, it is theoretically possible to produce a noble metal thin film with few impurities uniformly and at high speed by using a new type CVD apparatus, but the technology for making an actual product has not been established. It is a fact.

  The present invention has been made in view of the above situation. In order to produce a noble metal thin film with less impurities in the above-described CVD apparatus, a metal film for suppressing damage is applied only to the bottom surface of a substrate, particularly a fine hole. It is an object of the present invention to provide a metal film production apparatus and a metal film production method that can be produced uniformly and at high speed.

  In addition, the present invention has been made in view of the above situation, and in the CVD system of the new method as described above, a noble metal thin film with few impurities is uniformly and rapidly produced on the wall surface and bottom surface of a fine hole in the substrate. An object of the present invention is to provide a metal film manufacturing apparatus and a metal film manufacturing method that can be used.

  Further, the present invention has been made in view of the above situation, and in the above-described new type CVD apparatus, the ferroelectric material is uniformly distributed inside the hole of the substrate in which the noble metal thin film is formed on the wall surface and bottom surface of the fine hole. And it aims at providing the metal film preparation apparatus and metal film preparation method which can be produced at high speed.

  The present invention has been made in view of the above situation. In the new CVD apparatus as described above, the transistor is connected to the inside of the hole of the substrate in which the noble metal thin film is formed on the wall surface and bottom surface of the fine hole. An object of the present invention is to provide a capacitor manufacturing apparatus capable of manufacturing a ferroelectric material uniformly and at high speed.

  The present invention has been made in view of the above situation. In the new CVD apparatus as described above, the transistor is connected to the inside of the hole of the substrate in which the noble metal thin film is formed on the wall surface and bottom surface of the fine hole. An object of the present invention is to provide a ferroelectric memory manufacturing apparatus capable of producing a ferroelectric material uniformly and at high speed.

In order to achieve the above object, a metal film manufacturing apparatus of the present invention according to claim 1 is provided.
A chamber in which a substrate having a fine hole formed on the surface is stored;
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;
By adjusting the temperature on the substrate side to be lower than the temperature of the member to be etched, the metal component of the precursor can be deposited on the substrate side, and the metal component of the precursor is deposited only on the bottom surface of the fine hole on the surface. and means,
The control adjustment means functions to increase the coverage, which is (the metal coating thickness of the bottom surface / the metal coating thickness of the wall surface) of the fine holes, by controlling the temperature on the substrate side to the low temperature side.
Characterized in that it comprises a.

The present invention according to claim 2
The metal film manufacturing apparatus according to claim 1 ,
The member to be etched is a refractory metal having a melting point of 1500 ° C. or higher.

In order to achieve the above object, a metal film manufacturing apparatus of the present invention according to claim 3 is provided.
A chamber that accommodates a substrate in which a fine hole is formed on the surface and a refractory metal film is formed only on the bottom surface;
A member to be etched made of noble metal provided in a chamber at a position where the substrate faces;
A source gas supply means for supplying a source gas containing halogen into the chamber;
Plasma generating means for generating a precursor of a noble metal component contained in the member to be etched and a source gas by generating a source gas plasma by plasmaizing the inside of the chamber and etching the member to be etched with the source gas plasma;
By making the temperature on the substrate side lower than the temperature of the member to be etched, the noble metal component of the precursor can be deposited on the substrate side, and at the same time, the noble metal component of the precursor is deposited on the bottom surface and the wall surface of the fine holes on the surface. and an adjustment means,
The control / adjusting means controls the temperature on the substrate side so that the coverage of the fine holes (the thickness of the noble metal coating on the bottom surface / the thickness of the noble metal coating on the wall surface) is approximately 1 or 1.
Characterized in that it comprises a.

The present invention according to claim 4 provides
In the metal film production apparatus of Claim 3 ,
The member to be etched is a noble metal having a high catalytic property with respect to the substrate.

According to the present invention, in order to produce a noble metal thin film, a metal film (especially a refractory metal) for suppressing damage can be produced uniformly and at high speed only on the bottom surface of a substrate, particularly a fine hole. An apparatus can be provided, and a metal thin film can be formed only on the bottom surface of a fine hole by temperature control.

Further, since the member to be etched is a refractory metal having a melting point of 1500 ° C. or higher, a refractory metal having a melting point of 1500 ° C. or higher can be produced only on the bottom surface of a fine hole.

Further, according to the present invention, it is possible to provide a metal film production apparatus capable of producing a noble metal thin film with few impurities uniformly and at high speed on the wall surface and bottom surface of a substrate, in particular, fine holes, and temperature control. Thus, a noble metal thin film can be formed on the wall surface and bottom surface of the fine hole.

In addition, since the member to be etched is a noble metal having a high catalytic property with respect to the substrate, a metal film production apparatus capable of producing a noble metal having a high catalytic property is obtained.

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

(First embodiment)
A fine hole (trench) is formed on the surface of the substrate that is the object of the present embodiment, and a film of a noble metal such as iridium (Ir) or platinum (Pt) is formed in the trench, and PZT (lead , Zinc, tantalum) and SBT (strontium, bismuth, tantalum) and other metal oxides sandwiched between noble metal films (electrodes). A capacitor is connected to the transistor to form a FeRAM (Ferroelectric Random Access Memory). By using a very thin ferroelectric film as a three-dimensional capacitor, it is possible to secure an area for storing electric charges and achieve miniaturization.

When a noble metal film such as iridium (Ir) or platinum (Pt) is formed in the trench, a new type CVD apparatus is used to etch the member to be etched made of noble metal by plasma of halogen gas (Cl ₂ gas). A precursor that is a chloride of a noble metal component is produced. Specifically, for example, Ir is applied as the member to be etched, and IrCl is formed as the precursor. Because Ir is hard metal becomes chloride, to obtain a IrCl taken for deposition, it is necessary to form a IrCl by supplying a large amount of Cl ₂ gas, at a Cl radical is supplied many Cl ₂ gas A certain amount of Cl ^* also increases, and damage due to Cl ^* occurs on the bottom surface of the trench of the substrate. For this reason, in this embodiment, the refractory metal film is formed only on the bottom surface of the trench so that the bottom surface of the trench is not damaged when the noble metal film is formed.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic side view of a metal film production apparatus for performing a metal film production method according to an embodiment of the present invention, FIG. 2 is a cross section showing a film formation state, and FIG. 3 is a relationship between temperature and coverage. The graph showing is shown. FIG. 4 is a graph showing the relationship between the Cl concentration and the depth position of the hole.

In the first embodiment, Cl ₂ gas as a source gas containing halogen is supplied into a chamber provided with an etching target member made of tantalum (Ta), which is a refractory metal having a melting point of 1500 ° C. or higher. to form a precursor TaCl the Ta component and Cl ₂ gas contained in the etched member by etching the etched member with Cl ₂ gas plasma is generated against the etched member, the fine holes on the surface (trench) is By making the temperature of the formed substrate side lower than the temperature of the member to be etched, the Ta component of the precursor TaCl can be formed on the surface of the substrate, and the (metal coating thickness of the bottom surface / metal coating of the wall surface of the trench) Cl ₂ gas component amount adjustment (by specifically lowering the temperature of the substrate side changing the absolute amount of Cl ₂ gas in a state such that the thickness) of coverage greater than 1 Rather Cl ₂ to a state of controlling the gas component amount) only the bottom surface of the trench is deposited Ta components by.

  The refractory metal is not limited to tantalum (Ta), and nickel or copper having a melting point of 1000 ° C. or higher can be applied.

  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 shape of the chamber is not limited to a cylindrical shape, and for example, a rectangular chamber can be applied.

  Although details will be described later, a fine hole (trench) is formed on the surface of the substrate 3, and metal oxides such as PZT (lead, zinc, tantalum) and SBT (strontium, bismuth, tantalum), which are ferroelectric substances, are formed in the trench. A capacitor having a three-dimensional structure in which an object is sandwiched between electrodes of noble metal such as iridium (Ir) or platinum (Pt) is formed. A capacitor is connected to the transistor to form a FeRAM (Ferroelectric Random Access Memory). By using a very thin ferroelectric film as a three-dimensional capacitor, it is possible to secure an area for storing electric charges and achieve miniaturization.

  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 tantalum (Ta) 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. Has been. 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 mesh | network form.

Around the cylindrical portion of the chamber 1, a plurality of nozzles 14 as source gas supply means for supplying source gas (Cl ₂ gas) 21 containing chlorine as halogen into the chamber 1 are arranged at equal intervals in the circumferential direction (for example, 8 locations: 2 locations are shown). 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.

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 etching target member 11 made of Ta, the etching target member 11 is heated and an etching reaction occurs in Ta. The reaction at this time is represented by the following formula, for example.
Ta (s) + Cl ^* → TaCl (g) (2)
Here, s represents a solid state and g represents a gas state. Formula (2) is a state in which Ta is etched by the gas plasma 20 to become 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.
TaCl (g) → TaCl (ad) (3)

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

Further, a part of the gasified TaCl (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.
TaCl (g) + Cl ^* → Ta (g) + Cl ₂ ↑ (5)
Thereafter, the Ta component in the gas state is formed on the substrate 3 so that a Ta thin film can be produced.

  As shown in FIG. 2, the Ta thin film 18 is formed only on the bottom surface 21 a of the trench 21 of the substrate 3. When the Ta thin film 18 is formed only on the bottom surface 21a, the temperature control means 6 sets the temperature of the substrate 3 to a temperature lower than the temperature of the member 11 to be etched (for example, 100 ° C. to 300 ° C.). The temperature of the substrate 3 is controlled to the low temperature side (control adjustment means).

  When the film is formed in the trench of the substrate 3 with the above-described apparatus, the power, pressure, time, etc. are optimized, and the temperature is changed (the metal coating thickness on the bottom surface / the metal coating thickness on the wall surface). Can be controlled. That is, as shown in FIG. 3, the coverage ratio (the metal coating thickness Tb of the bottom surface 21a / the metal coating thickness Tw of the wall surface 21b) in the trench 21 of the substrate 3 has a coverage value of 1 in a region where the temperature is low. The value of the metal coating thickness Tb of the bottom surface 21a becomes large and converges to 1 by raising the temperature. That is, the metal coating thickness Tb of the bottom surface 21a and the metal coating thickness Tw of the wall surface 21b become equal, and conformal formation is achieved. A membrane becomes possible.

  For this reason, since the Ta thin film 18 is formed only on the bottom surface 21a of the trench 21 of the substrate 3, the temperature of the substrate 3 is controlled to the low temperature side (metal coating thickness Tb of the bottom surface 21a / metal coating thickness Tw of the wall surface 21b). The coverage ratio is made larger than 1, and the value of the metal coating thickness Tb of the bottom surface 21a of the trench 21 is increased. Thereby, the Ta thin film 18 can be formed only on the bottom surface 21 a of the trench 21.

As a control adjustment means for forming the Ta thin film 18 only on the bottom surface 21a of the trench 21 of the substrate 3, the supply amount of the Cl ₂ gas 21 can be controlled. Specifically, as shown in FIG. 4, the value of the Cl concentration on the bottom surface 21 a side (lower depth side) of the trench 21 is decreased, and the value of the Cl concentration on the upper depth side of the trench 21 is increased. In other words, by increasing the supply amount of the Cl ₂ gas 21 in the initial stage and gradually decreasing the supply amount of the Cl ₂ gas 21, the etching on the entrance side of the trench 21 is promoted. The Ta thin film 18 may be formed only on the bottom surface 21a of the trench 21 of the substrate 3 while suppressing etching by the chlorine radical Cl ^* on the bottom surface 21a side.

Therefore, in order to produce a noble metal thin film such as iridium (Ir) or platinum (Pt), the Ta thin film 18 that suppresses etching damage due to the chlorine radical Cl ^* is uniformly and fast only on the bottom surface 21a of the trench 21 of the substrate 3. It can be set as the metal film preparation apparatus which can be produced. Further, the Ta thin film 18 can be formed only on the bottom surface 21a of the trench 21 by temperature control.

(Second embodiment)
A second embodiment will be described with reference to FIG. FIG. 5 shows a cross section showing a film formation state in the second embodiment.

  In the second embodiment, the substrate 3 on which the Ta thin film 18 is formed only on the bottom surface 21a of the trench 21 in the first embodiment is the substrate 3 to be formed, and the member to be etched is compared with the apparatus shown in FIG. Are different. As a member to be etched, a member to be etched made of iridium (Ir), which is a noble metal, is applied, and the other configurations are the same. For this reason, detailed description of the configuration of the apparatus is omitted. In addition, as a noble metal, it is also possible to apply a noble metal having catalytic action such as gold or platinum.

That is, as shown in FIG. 1, Cl ₂ gas as a source gas containing halogen is supplied into a chamber 1 provided with a highly catalytic Ir member to be etched, and plasma is applied to the member to be etched. to form a precursor IrCl the Ir component and Cl ₂ gas contained in the etched member by etching the etched member with Cl ₂ gas is generated, Ta only the bottom surface 21a together with the trench 21 is formed on the surface thereof The Ir component of the precursor IrCl can be formed on the surface of the substrate 3 by lowering the temperature of the substrate 3 on which the thin film 18 is produced to be lower than the temperature of the member to be etched. Adjust the amount of Cl ₂ gas component so that the coverage ratio is about 1 or 1 (specifically, the temperature on the substrate side is adjusted). Deposited in the trench 21 of the substrate 3 Ta film 18 is produced only on the bottom surface 21a by Cl than ₂ changing the absolute amount of gas into a state of controlling the Cl ₂ gas component amount not) to the Ir conformally Let

  The reaction when the member to be etched is made of Ir is obtained by replacing Ta in the formulas (1) to (5) in the first embodiment with Ir. As shown in FIG. 5, an Ir thin film 25 is conformally formed on the bottom surface and the wall surface of the trench 21 of the substrate 3 on which the Ta thin film 18 is formed only on the bottom surface 21 a of the trench 21. When forming the Ir thin film 25 conformally on the bottom surface and the wall surface of the trench 21, the temperature control means 6 controls the temperature of the substrate 3 (control adjustment means).

  When the film is formed conformally in the trench 21 of the substrate 3 with the above-described apparatus, the power, pressure, time, etc. are optimized and the temperature is changed, as can be seen from the graph shown in FIG. It is possible to control the coverage, which is (precious metal coating thickness / wall surface precious metal coating thickness). That is, as shown in FIG. 3, the coverage ratio (the noble metal coating thickness Tb of the bottom surface 21a / the noble metal coating thickness Tw of the wall surface 21b) in the trench 21 of the substrate 3 has a coverage value of 1 in a low temperature region. The value of the noble metal coating thickness Tb of the bottom surface 21a is greatly increased and converges to 1 by increasing the temperature. That is, the noble metal coating thickness Tb of the bottom surface 21a and the noble metal coating thickness Tw of the wall surface 21b become equal, and conformal formation is achieved. A membrane becomes possible.

  For this reason, in order to form the conformal Ir thin film 25 on the bottom surface and the wall surface of the trench 21 of the substrate 3 having the Ta thin film 18 formed only on the bottom surface 21a, the temperature of the substrate 3 is controlled (the noble metal on the bottom surface 21a). The coverage which is the coating thickness Tb / the noble metal coating thickness Tw of the wall surface 21b) is set to approximately 1 or 1. Thereby, the conformal Ir thin film 25 can be formed on the bottom surface and the wall surface of the trench 21 of the substrate 3 in which the Ta thin film 18 is formed only on the bottom surface 21a.

Incidentally, as a control adjustment means for forming a conformal Ir thin film 25 on the bottom surface and the wall surface of the trench 21 of the substrate 3 in which the Ta thin film 18 is formed only on the bottom surface 21a, the supply amount of the Cl ₂ gas 21 is controlled. Is also possible. Specifically, contrary to the state of the first embodiment, the supply amount of the Cl ₂ gas 21 is initially reduced and the supply amount of the Cl ₂ gas 21 is gradually increased, so that the entrance is formed at the initial stage of film formation. The film thickness of the chloride in the vicinity is increased, and the film of the bottom surface 21a is formed in the latter stage of the film formation while the excessively added chloride in the vicinity of the entrance is excessively etched. As a result, the film thickness of the bottom surface and the wall surface is equal. You may make it become.

Accordingly, the Ir thin film 25 with less impurities is uniformly and rapidly formed on the wall surface and the bottom surface of the trench 21 of the substrate 3 in which the Ta thin film 18 that suppresses etching damage due to the chlorine radical Cl ^* is formed only on the bottom surface 21a. It can be set as the metal film preparation apparatus which can be manufactured. Further, the Ir thin film 25 can be formed on the wall surface and bottom surface of the trench 21 of the substrate 3 in which the Ta thin film 18 is formed only on the bottom surface 21a by temperature control.

  After the Ir thin film 25 is formed on the wall surface and the bottom surface of the trench 21 of the substrate 3 where the Ta thin film 18 is formed only on the bottom surface 21a, the Ir thin film 25 on the surface of the substrate 3 is removed by existing polishing or the like to remove the trench 21. The Ir thin film 25 is present only on the wall surface and the bottom surface.

(Third embodiment)
A third embodiment will be described with reference to FIG. FIG. 6 shows a cross section showing the film formation state in the third embodiment.

  In the third embodiment, the substrate 3 on which the Ta thin film 18 is formed on the bottom surface 21a of the trench 21 and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21 in the second embodiment is the substrate 3 to be formed. Thus, the member to be etched is different from the apparatus shown in FIG. As the member to be etched, a metal or a ferroelectric oxide constituting a ferroelectric is applied, and the other configurations are the same. For this reason, detailed description of the configuration of the apparatus is omitted. In other words, lead, zinc, tantalum, and strontium, bismuth, and tantalum constituting SBT are applied as the member to be etched. In this case, although explanation is omitted, oxidation treatment is performed after film formation in order to finally form an oxide. Alternatively, PZT or SBT itself is applied as the member to be etched. In the following embodiments, PZT constituting lead, zinc, tantalum, and SBT constituting strontium, bismuth, tantalum, or PZT and SBT are collectively referred to as a ferroelectric S.

  When lead, zinc, tantalum constituting PZT, and strontium, bismuth, and tantalum constituting SBT are used as members to be etched, a plurality of kinds of metal members to be etched are arranged in one chamber to form an oxide alloy. It is possible to form an oxide alloy by forming a film or stacking different kinds of metals.

That is, as shown in FIG. 1, Cl ₂ gas as a source gas containing halogen is supplied into a chamber 1 provided with a member to be etched made of ferroelectric S, and plasma is generated on the member to be etched. to form a precursor SCl the ferroelectric S component and Cl ₂ gas contained in the etched member by etching the etched member with Cl ₂ gas is generated on the surface by the bottom surface 21a together with the trench 21 is formed On the other hand, the temperature of the substrate 3 on which the Ta thin film 18 is formed and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21 is made lower than the temperature of the member to be etched. It is possible to form a film on the surface, and at the same time, the coverage ratio of the trench 21 (the thickness of the ferroelectric S coating on the bottom surface / the thickness of the ferroelectric S coating on the wall surface) is approximately 1 or 1. The Cl ₂ gas component amount adjusted by (specifically a state of controlling the Cl ₂ gas component amount instead of changing the absolute amount of Cl ₂ gas by adjusting the temperature of the substrate side) of the substrate 3 The ferroelectric S is formed in the trench 21 conformally.

  The reaction when the member to be etched is made of the ferroelectric S is obtained by replacing Ta in the formulas (1) to (5) in the first embodiment with the ferroelectric S. As shown in FIG. 6, the Ta thin film 18 is formed only on the bottom surface 21 a of the trench 21, and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21. The dielectric S thin film 26 is formed conformally. When the ferroelectric S thin film 26 is formed on the bottom and wall surfaces of the trench 21 conformally, the temperature of the substrate 3 is controlled by the temperature control means 6 (control adjustment means).

  When the film is formed conformally in the trench 21 of the substrate 3 with the above-described apparatus, the power, pressure, time, etc. are optimized and the temperature is changed, as can be seen from the graph shown in FIG. It is possible to control the coverage, which is (ferroelectric S coating thickness / wall surface ferroelectric S coating thickness). That is, as shown in FIG. 3, the coverage ratio (the ferroelectric S coating thickness Tb of the bottom surface 21a / the ferroelectric S coating thickness Tw of the wall surface 21b) in the trench 21 of the substrate 3 is covered in a region where the temperature is low. The value of the ratio is larger than 1 and the value of the ferroelectric S coating thickness Tb on the bottom surface 21a becomes large and converges to 1 when the temperature is raised. That is, the ferroelectric S coating thickness Tb of the bottom surface 21a and the wall surface 21b Ferroelectric S coating thickness Tw becomes equal, and conformal film formation becomes possible.

  Therefore, the Ta thin film 18 is formed only on the bottom surface 21a, and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21, and the conformal ferroelectric S thin film 26 is formed on the bottom surface and wall surface of the trench 21 of the substrate 3. In order to form a film, the temperature of the substrate 3 is controlled so that the coverage, which is (the ferroelectric S coating thickness Tb of the bottom surface 21a / the ferroelectric S coating thickness Tw of the wall surface 21b), is set to approximately 1 or 1. Thereby, the Ta thin film 18 is formed only on the bottom surface 21a, and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21, and the conformal ferroelectric S thin film 26 is formed on the bottom surface and wall surface of the trench 21 of the substrate 3. A film can be formed.

As a control adjustment means for forming the conformal ferroelectric S thin film 26, the supply amount of the Cl ₂ gas 21 can be controlled as described above. Specifically, contrary to the state of the first embodiment, the supply amount of the Cl ₂ gas 21 is initially reduced and the supply amount of the Cl ₂ gas 21 is gradually increased, so that the entrance is formed at the initial stage of film formation. The film thickness of the chloride in the vicinity is increased, and the film of the bottom surface 21a is formed in the latter stage of the film formation while the excessively added chloride in the vicinity of the entrance is excessively etched. As a result, the film thickness of the bottom surface and the wall surface is equal. You may make it become.

Therefore, a Ta thin film 18 that suppresses etching damage due to chlorine radical Cl ^* is formed only on the bottom surface 21a, and an Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21, and on the wall surface and bottom surface of the trench 21 of the substrate 3. A metal film manufacturing apparatus capable of manufacturing the ferroelectric S thin film 26 with few impurities uniformly and at high speed can be obtained. Further, the ferroelectric thin film 26 is formed on the wall surface and bottom surface of the trench 21 of the substrate 3 in which the Ta thin film 18 is formed only on the bottom surface 21a by temperature control and the Ir thin film 25 is formed only on the wall surface and bottom surface of the trench 21. can do.

  Then, as shown in FIG. 7 showing a cross section of the capacitor, an Ir thin film 25 is formed on the surface of the ferroelectric S thin film 26 using the metal film manufacturing apparatus of the second embodiment shown in FIG. The capacitor 28 has a three-dimensional structure in which the body S is sandwiched between Ir thin films 25 (electrodes). The Ir thin film 25 formed on the surface of the ferroelectric S thin film 26 can be manufactured not only by using a metal film manufacturing apparatus but also by patterning or the like.

  As shown in FIG. 8, the above-described three-dimensional capacitor 28 is connected to a transistor 31 to form a FeRAM (Ferroelectric Random Access Memory) 32. By using a very thin ferroelectric film as the three-dimensional capacitor 28, it is possible to secure an area for storing electric charges and achieve miniaturization.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIG. In the fourth embodiment, the metal film production apparatuses of the above-described embodiment examples are arranged side by side, provided with a moving means for transporting the substrate between the metal film production apparatuses, and further, the film formation in each metal film production apparatus A ferroelectric memory manufacturing apparatus (capacitor) for manufacturing a capacitor (ferroelectric memory) by continuously performing film formation on a substrate by interlocking the moving means and the control means. Manufacturing equipment). FIG. 9 shows a schematic plan view of a ferroelectric memory manufacturing apparatus (capacitor manufacturing apparatus).

  As shown in the figure, a polygonal vacuum chamber 35 is provided with an arm mechanism 36 composed of an open / close arm and a gripping arm so as to be rotatable, and a substrate processing chamber 37 is connected to the vacuum chamber 35. A substrate 3 on which a metal film is formed is carried into the substrate processing chamber 37, or the substrate 3 on which a desired film formation has been completed is transferred and subjected to a predetermined process. Around the polygonal vacuum chamber 35, the metal film production apparatus according to the first embodiment, the metal film production apparatus according to the second embodiment, the metal film production apparatus according to the third embodiment, and the first embodiment example. The metal film production apparatuses are sequentially arranged, and the substrate 3 is carried in and out by an arm mechanism 36 as a moving means.

  The operation of the metal film manufacturing apparatus is controlled by the control means 38. That is, the film forming operation of the metal film manufacturing apparatus is controlled in conjunction with each other, and the film formation on the substrate 3 is simultaneously performed in each metal film manufacturing. Then, the operation of the arm mechanism 36 as the moving means is interlocked with the control means, and the film formation of the substrate 3 is continuously performed.

  The substrate 3 is carried in and out by the arm mechanism 36 between the substrate processing chamber 37 and each metal film manufacturing apparatus, and the simultaneous film formation is sequentially repeated with the transport and film formation being interlocked by the control means 38. Thus, a substrate on which the three-dimensional capacitor 28 or the FeRAM 32 is configured is efficiently manufactured. Accordingly, the capacitor manufacturing apparatus can uniformly and rapidly manufacture the noble metal thin film and the ferroelectric. In addition, a ferroelectric memory manufacturing apparatus that can produce a ferroelectric memory by forming a noble metal thin film and a ferroelectric uniformly and at high speed to form a capacitor connected to a transistor.

(Fifth embodiment)
Another embodiment of the metal film manufacturing apparatus will be described. FIG. 10 shows a schematic side view of a metal film manufacturing apparatus according to another embodiment of the present invention.

  The metal film manufacturing apparatus of the fifth embodiment is obtained by adding a part of the configuration to the first to third embodiments. Examples of the member to be etched include tantalum (Ta) which is a high melting point metal and is formed only on the bottom surface of the trench, iridium (Ir) which is a noble metal, lead, zinc which constitutes PZT, strontium which constitutes tantalum and SBT, Bismuth, tantalum, or PZT or SBT itself can be applied. Therefore, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and all materials as members to be etched are collectively described as M.

  In the metal film manufacturing apparatus of the fifth embodiment, a source gas containing halogen is introduced into a chamber provided with an etched member formed of a metal material applied in the first to third embodiments. Supplying a source gas plasma to the member to be etched and etching the member to be etched with the source gas plasma to generate a precursor of the metal component and the source gas contained in the member to be etched, and the temperature on the substrate side The precursor is formed into a film on the substrate by lowering the temperature of the member to be etched, the radical excited by the halogen gas is supplied corresponding to the member to be etched, and the metal component of the precursor formed on the substrate is The film is formed by deposition.

  As shown in FIG. 10, for example, a support base 2 is provided near the bottom of a chamber 1 made of, for example, ceramics (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 shape of the chamber is not limited to a cylindrical shape, and for example, a rectangular chamber can be applied.

  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 11 to be etched made of a desired metal material M. The member 11 to be etched is disposed between the substrate 3 and the ceiling plate 7 in a discontinuous state with respect to the flow of electricity of the plasma antenna 8. Yes. 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 mesh | network form.

Around the cylindrical portion of the chamber 1, a plurality of nozzles 14 serving as source gas supply means for supplying source gas (Cl ₂ gas) 21 containing chlorine as halogen into the chamber 1 are arranged at equal intervals in the circumferential direction (for example, 8 locations: 2 locations are shown). 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.

  A slit-like opening 41 that opens into the chamber 1 is formed below the member to be etched 11 in the cylindrical portion of the chamber 1, and one end of a cylindrical passage 42 is fixed to the opening 41. A cylindrical excitation chamber 43 formed of an insulator is provided in the middle of the passage 42, and a coiled plasma antenna 44 is wound around the excitation chamber 43.

A matching unit 45 and a power source 46 are connected to the plasma antenna 44 to supply power. A flow rate controller 47 is connected to the other end side of the passage 42, and Cl ₂ gas for obtaining Cl ^* is supplied into the passage 42 via the flow rate controller 47. The plasma antenna 44, the matching unit 45, the power source 46, and the flow rate controller 47 constitute a halogen gas radical supply means.

In the thin film manufacturing apparatus described above, Cl ₂ gas 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 ^* (11)
Here, Cl ^* represents a chlorine radical.

When the gas plasma 20 acts on the member 11 to be etched, the member 11 to be etched is heated and an etching reaction occurs in M. The reaction at this time is represented by the following formula, for example.
M (s) + Cl ^* → MCl (g) (12)
Here, s represents a solid state and g represents a gas state. Formula (12) is a state in which M is etched by the gas plasma 20 to be a precursor 51.

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 51 is adsorbed (deposited) on the substrate 3. The reaction at this time is represented by the following formula, for example.
MC1 (g) → MC1 (ad) (13)

In this state, the Cl ₂ gas 21 from the nozzle 14 is stopped, and at the same time, chlorine radical Cl ^* is supplied from the passage 42 into the chamber 1. MCl adsorbed on the substrate 3 is reduced by the chlorine radical Cl ^* to become an M component, whereby an M thin film can be produced. The reaction at this time is represented by the following formula, for example.
MCl (ad) + Cl ^* → M (s) + Cl ₂ ↑ (14)

Further, a part of the gasified MCl (g) generated in the above formula (12) is reduced by the chlorine radical Cl ^* before being adsorbed on the substrate 3 (see the above formula (13)), and is in a gaseous state. It becomes. The reaction at this time is represented by the following formula, for example.
MCl (g) + Cl ^* → M (g) + Cl ₂ ↑ (15)
Thereafter, the gaseous M component is deposited on the substrate 3 so that an M thin film can be produced.

In the metal film manufacturing apparatus described above, MCl adsorbed on the substrate 3 is reduced using chlorine radical Cl ^* from the excitation chamber 43 and an M thin film is manufactured, so that damage to the substrate due to plasma is minimized. It becomes possible.

  INDUSTRIAL APPLICABILITY The present invention can be used, for example, in the industrial field of a metal film production apparatus and a metal film production method for producing a refractory metal or a noble metal into fine holes.

  Further, the present invention can be used in the industrial field of a metal film manufacturing apparatus and a metal film manufacturing method for manufacturing a ferroelectric film on a substrate in which a refractory metal or a noble metal is formed in a fine hole.

  The present invention also relates to a capacitor manufacturing apparatus for manufacturing a capacitor by manufacturing a ferroelectric film on a substrate on which a refractory metal or a noble metal is laminated, and a ferroelectric material for manufacturing a ferroelectric memory in which a capacitor and a transistor are connected. It can be used in the industrial field of memory manufacturing equipment.

It is a schematic side view of the metal film preparation apparatus which enforces the metal film preparation method concerning one embodiment of the present invention. It is sectional drawing showing the film-forming condition. It is a graph showing the relationship between temperature and a coverage. It is a graph showing the relationship between Cl concentration and the depth position of a hole. It is sectional drawing showing the film-forming condition in the example of 2nd Embodiment. It is sectional drawing showing the film-forming condition in the example of 3rd Embodiment. It is sectional drawing of a capacitor. It is a schematic sectional drawing of FeRAM. It is a schematic plan view of a ferroelectric memory manufacturing apparatus (capacitor manufacturing apparatus). It is a schematic side view of the metal film preparation apparatus which concerns on the other embodiment of this invention.

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 source 11 Member to be etched 12 Projection part 13 Ring part 14 Nozzle 15 Flow rate controller 16 Exhaust port 17 Vacuum apparatus 18 Ta thin film 21 Trench 25 Ir thin film 26 Ferroelectric S thin film 28 Capacitor 31 Transistor 32 FeRAM
35 Polygon type vacuum chamber 36 Arm mechanism 37 Substrate processing chamber

Claims (4)

A chamber in which a substrate having a fine hole formed on the surface is stored;
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;
By adjusting the temperature on the substrate side to be lower than the temperature of the member to be etched, the metal component of the precursor can be deposited on the substrate side, and the metal component of the precursor is deposited only on the bottom surface of the fine hole on the surface. and means,
The control adjusting means functions to increase the coverage ratio, which is a fine hole (the thickness of the metal coating on the bottom surface / the thickness of the metal coating on the wall surface), from 1 by controlling the temperature on the substrate side to the low temperature side.
An apparatus for producing a metal film, comprising: The metal film manufacturing apparatus according to claim 1 ,
The member to be etched is a refractory metal having a melting point of 1500 ° C. or higher. A chamber that accommodates a substrate in which a fine hole is formed on the surface and a refractory metal film is formed only on the bottom surface;
A member to be etched made of noble metal provided in a chamber at a position where the substrate faces;
A source gas supply means for supplying a source gas containing halogen into the chamber;
Plasma generating means for generating a precursor of a noble metal component contained in the member to be etched and a source gas by generating a source gas plasma by plasmaizing the inside of the chamber and etching the member to be etched with the source gas plasma;
By making the temperature on the substrate side lower than the temperature of the member to be etched, the noble metal component of the precursor can be deposited on the substrate side, and at the same time, the noble metal component of the precursor is deposited on the bottom surface and the wall surface of the fine holes on the surface. and an adjustment means,
The control / adjusting means controls the temperature on the substrate side so that the coverage of the fine holes (the thickness of the noble metal coating on the bottom surface / the thickness of the noble metal coating on the wall surface) is approximately 1 or 1.
An apparatus for producing a metal film, comprising: In the metal film production apparatus of Claim 3 ,
The metal film manufacturing apparatus, wherein the member to be etched is a noble metal having high catalytic properties with respect to the substrate.

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