JP2004076123A - Apparatus for fabricating metallic film, and cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and perfectly clean the surface of a member to be etched. <P>SOLUTION: The cleaning work of the member to be etched of the apparatus for fabricating metallic films is easily performed with high efficiency by generating a cleaning gaseous plasma when CuCl sticks to the surface of the member 18 to be cleaned and by removing the Cl on the surface of the member 18 as Cl<SB>2</SB>by Cl<SP>*</SP>thereby efficiently and completely performing the cleaning on the surface of the member to be etched. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal film forming apparatus for forming a metal film on a surface of a substrate by a vapor phase growth method and a cleaning method.
[0002]
[Background Art]
Conventionally, when a metal film, for example, a copper thin film is produced by a vapor phase growth method, for example, a liquid organometallic complex such as copper, hexafluoroacetylacetonato, or trimethylvinylsilane is used as a raw material, and a solid raw material is used as a solvent. The film is formed on the substrate by dissolving it into a gas and vaporizing it using a thermal reaction.
[0003]
However, in this conventional technique, it is difficult to improve the film formation rate because of the film formation utilizing a thermal reaction, and the metal complex used as a raw material is expensive, and the hexagon accompanying copper is expensive. Since fluoroacetylacetonato and trimethylvinylsilane remain as impurities in the copper thin film, there is a disadvantage that it is difficult to improve the film quality.
[0004]
In contrast, the present inventors have obtained the following findings. That is, chlorine gas was supplied into a vacuum chamber for accommodating a substrate, and the chlorine gas was turned into plasma by plasma generation means, while the member to be etched formed of a copper plate disposed in the chamber was etched with chlorine gas plasma. In this case, by appropriately controlling the temperature relationship between the copper plate and the substrate, the etched copper can be deposited on the substrate to form a copper thin film. That is, the copper plate serving as the etching member is heated to a high temperature (for example, 300 ° C.). When the temperature of the substrate is lowered (about 200 ° C.), a copper thin film can be formed on the substrate.
[0005]
Therefore, while the copper plate is provided facing the chlorine gas plasma forming a relatively high-temperature atmosphere, the substrate is provided in a relatively low-temperature atmosphere opposed to the copper plate with the plasma atmosphere interposed therebetween, and the temperatures of both are reduced. Appropriate control can easily provide a Cu thin film manufacturing apparatus. Here, as the member to be etched, in addition to Cu, any metal that can form a high vapor pressure halide, such as Ta, Ti, W, etc., can be generally used.₂Besides, any halogen gas can be generally used.
[0006]
In a metal film manufacturing apparatus based on such knowledge, for example, when forming a Cu thin film, first, an Ar gas is supplied into a chamber to form this plasma, and thereby the member to be etched formed of Cu is brought to a predetermined temperature. When the member to be etched reaches a predetermined temperature by preheating, Cl₂A gas is supplied to form the plasma. As a result, the member to be etched is Cl₂It is etched by gas plasma to generate a Cu precursor (CuxCly). This precursor (CuxCly) is transported to the substrate, which is a relatively low temperature part, and is adsorbed on the surface of the substrate as CuCl. Then, ClCl is added to the CuCl adsorbed on the substrate.^*Acts to extract Cl and deposit a Cu thin film on the surface of the substrate.
[0007]
That is, it is considered that the following reaction occurs in the above-described metal film manufacturing apparatus.
(1) Dissociation reaction of plasma; Cl₂→ 2Cl^*
(2) Etching reaction; Cu + Cl^*→ CuCl (g)
(3) Adsorption reaction on the substrate; CuCl (g) → CuCl (ad)
{Circle around (4)} Film formation reaction; CuCl (ad) + Cl^*→ Cu + Cl₂↑
Where Cl^*Represents a Cl radical, (g) represents a gas state, and (ad) represents an adsorption state.
[0008]
In the film forming process as described above, depending on the film forming conditions, CuCl is also adsorbed on the member to be etched and solidified to form a CuCl film. When such a phenomenon is repeated and, for example, the entire region of the surface of the member to be etched formed of Cu is covered with CuCl, Cl₂The etching reaction of the member to be etched by the gas plasma does not proceed.
[0009]
Here, the film forming conditions under which the CuCl film easily adheres to the member to be etched are Cl gas as a source gas.₂This is easily achieved when the gas pressure of the gas is high or when the temperature of the member to be etched is low.
[0010]
By the way, in the state where the film is formed at a low power, when the supply of power is cut off at the end of the film formation, the temperature of the member to be etched is lowered with the cutoff of the power.₂Due to the gas, the temperature of the member to be etched is low and Cl₂The condition that the gas pressure of the gas is high is satisfied. Therefore, the adsorption reaction of CuCl on the member to be etched proceeds particularly at the end of the film forming step with low power.
[0011]
Therefore, in the metal film manufacturing apparatus as described above, so-called cleaning, in which Cl is removed from the CuCl film adhering to the surface of the member to be etched in the film forming step at each film forming step or after a predetermined number of film forming steps, is performed. There is a need to.
[0012]
[Problems to be solved by the invention]
However, the cleaning method generally used in plasma processing apparatuses, such as the above-described metal film forming apparatus, removes a CuCl film adhered to the inner wall or ceiling of the chamber, and removes the surface of the member to be etched. At present, a technology for removing Cl from the CuCl film adhering to the substrate has not been established.
[0013]
The present invention has been made in view of the above-described problems, and has as its object to provide a metal film manufacturing apparatus and a cleaning method that can easily and efficiently perform a cleaning operation of a member to be etched in the metal film manufacturing apparatus.
[0014]
[Means for Solving the Problems]
The metal film production apparatus of the present invention for achieving the above object,
A chamber in which the substrate is accommodated;
A member to be etched made of metal disposed in the chamber;
Source gas supply means for supplying a source gas containing halogen,
Plasma generation 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 and etching the member to be etched,
Temperature control means for lowering the temperature on the substrate side to a temperature lower than the temperature on the member to be etched side and forming a metal component of the precursor on the substrate,
Cleaning gas supply means for supplying a cleaning gas containing halogen; cleaning gas plasma generation means for generating cleaning gas plasma to etch the surface of the member to be etched to remove halogen attached to the surface of the member to be etched;
It is characterized by having.
[0015]
And in the metal film production apparatus according to claim 1,
The cleaning gas supply unit supplies the cleaning gas to a position where the supplied cleaning gas reaches the member to be etched after the cleaning gas is converted into the cleaning gas plasma by the cleaning gas plasma generation unit.
[0016]
Further, in the metal film production apparatus according to claim 1 or 2,
The cleaning gas supply unit supplies a cleaning gas having a halogen concentration higher than the halogen concentration of the source gas supplied from the source gas supply unit.
[0017]
Further, in the metal film production apparatus according to any one of claims 1 to 3,
When generating the cleaning gas plasma by the cleaning gas plasma generating means, a bias power source is provided for shifting the potential of the member to be etched to the negative side.
[0018]
Further, in the metal film production apparatus according to any one of claims 1 to 4,
The halogen-containing source gas and the cleaning gas are a chlorine-containing source gas and a cleaning gas,
The cleaning gas supply means is constituted by the same supply system as the source gas supply means.
[0019]
Further, in the metal film production apparatus according to claim 5,
By forming the member to be etched from copper, CuxCly is generated as a precursor.
[0020]
Further, in the metal film production apparatus according to any one of claims 1 to 6,
The member to be etched is a halide-forming metal such as tantalum, tungsten or titanium.
[0021]
The cleaning method of the present invention to achieve the above object,
A metal film forming apparatus for forming a predetermined metal film on a substrate by etching a member to be etched formed of a metal for forming a high vapor pressure halide disposed inside a chamber with a plasma of a source gas containing halogen. In the cleaning method,
The surface of the member to be etched is etched with a cleaning gas plasma containing halogen to remove the halogen adhered to the surface of the member to be etched.
[0022]
And in the cleaning method according to claim 8,
The cleaning gas plasma is supplied toward the member to be etched.
[0023]
Further, in the cleaning method according to claim 8 or 9,
The halogen concentration of the cleaning gas is higher than the halogen concentration of the source gas.
[0024]
Further, in the cleaning method according to any one of claims 8 to 10,
When the surface of the member to be etched is etched by the cleaning gas plasma, the potential of the member to be etched is shifted to the negative side.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
The metal film manufacturing apparatus of the present invention supplies a raw material gas containing chlorine as a halogen into a chamber containing a metal (Cu) member to be etched, generates chlorine gas plasma, and is coated with the chlorine gas plasma. A precursor of the Cu component and the chlorine gas contained in the member to be etched is generated by etching the etching member, and the Cu component of the precursor is reduced by lowering the temperature on the substrate side than the temperature on the member side to be etched. The film is formed on the substrate.
[0026]
Then, when the precursor advances and CuCl is adsorbed on the member to be etched, the surface of the member to be etched is etched by the cleaning gas plasma to remove the Cl of the adsorbed CuCl.
[0027]
【Example】
Hereinafter, embodiments of a metal film manufacturing apparatus and a cleaning method according to the present invention will be described with reference to the drawings.
[0028]
First Embodiment A first embodiment of a metal film manufacturing apparatus and a cleaning method according to the present invention will be described with reference to FIG.
[0029]
FIG. 1 is a schematic side view of a metal film manufacturing apparatus for performing the cleaning method according to the first embodiment of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. The view is taken along the line III-III 矢.
[0030]
As shown in FIG. 1, a support 2 is provided near the bottom of a cylindrical chamber 1 made of metal (for example, aluminum), and a substrate 3 is placed on the support 2. The support 2 is provided with a temperature controller 6 having a heater 4 and a coolant circulating means 5. The support 2 is controlled by the temperature controller 6 to a predetermined temperature (for example, a temperature at which the substrate 3 is maintained at 100 to 200 ° C.). ) Is controlled.
[0031]
The upper surface of the chamber 1 is an opening, and the opening is closed by a disk-shaped ceiling plate 7 which is a ceiling member made of an insulating material (for example, made of ceramics). The inside of the chamber 1 closed by the ceiling plate 7 is maintained at a predetermined pressure by the vacuum device 8.
[0032]
A gas nozzle 12 serving as a source gas supply unit and a cleaning gas supply unit is provided around the support base 2 inside the chamber 1, and the gas nozzle 12 is provided with a source gas containing chlorine as a halogen via a flow rate control device 13. Cl diluted with He, Ar, etc. to a chlorine concentration of ≤50% ５０, preferably about 10% 等₂Gas) and a cleaning gas containing chlorine as a halogen (He, Ar, etc.), wherein the chlorine concentration is made higher than that of the raw material gas, and the Cl is diluted to about 30%.₂Gas), and a raw material gas and a cleaning gas are supplied from the gas nozzle 12 into the chamber 1.
[0033]
Cl as halogen₂Since the raw material gas and the cleaning gas are used and the supply systems of the raw material gas and the cleaning gas are made the same, the apparatus can be made simple using inexpensive raw materials. It is also possible to make the halogen concentration of the cleaning gas the same as the halogen concentration of the source gas and omit the control of the dilution concentration.
[0034]
Switching between the source gas and the cleaning gas (changing the concentration) is performed by the flow controller 13 during cleaning with Cl as halogen.₂This is performed by increasing the amount of gas relatively. The cleaning gas supply means may be provided independently of the source gas supply means, that is, a nozzle for exclusively supplying the cleaning gas may be provided.
[0035]
As the halogen contained in the source gas and the cleaning gas, fluorine (F), bromine (Br), iodine (I), or the like can be used.
[0036]
The angles of the source gas and the cleaning gas supplied from the gas nozzle 12 can be set to 90 degrees upward, or can be set to various angles by changing the angles in the circumferential direction. This makes it possible to arbitrarily set the supply state (plasma generation state) of the source gas and the cleaning gas.
[0037]
An etching member 18 made of metal (made of Cu) is sandwiched between the opening on the upper surface of the chamber 1 and the ceiling plate 7. As shown in FIGS. 1 and 2, the member to be etched 18 is provided with a ring portion 19 sandwiched in an upper portion of the chamber 1, and extends to the vicinity of a radial center portion of the chamber 1 on the inner peripheral side of the ring portion 19. A plurality (12 in the illustrated example) of protrusions 20 as bar members having the same width are provided in the circumferential direction.
[0038]
The protrusion 20 is attached to the ring 19 integrally or detachably. A notch 35 (space) formed between the projections 20 exists between the ceiling plate 7 and the inside of the chamber 1. The ring portion 19 is grounded, and the plurality of protrusions 20 are electrically connected and maintained at the same potential.
[0039]
In addition, it is also possible to arrange | position the 2nd projection part radially shorter than the projection part 20 between the projection parts 20, and also arrange | position a short projection part between the projection part 20 and a 2nd projection part. It is also possible. By doing so, it is possible to secure the area of copper to be etched while suppressing the induced current.
[0040]
A plasma antenna 9 for converting the inside of the chamber 1 into plasma is provided above the ceiling plate 7, and the plasma antenna 9 is formed in a planar ring shape parallel to the surface of the ceiling plate 7. The plasma antenna 9 is connected to a matching unit 10 and a power supply 11 as a plasma generation unit and a cleaning gas plasma generation unit, and is supplied with power.
[0041]
The raw material gas and the cleaning gas are supplied from the gas nozzle 12 toward the ceiling plate 7 at an angle of, for example, 45 degrees. That is, the cleaning gas is supplied to the position where the cleaning gas reaches the member to be etched 18 after being turned into plasma by the cleaning gas plasma generating means.
[0042]
The member to be etched 18 is provided with a plurality of protrusions 20 on the inner peripheral side of the ring portion 19 in the circumferential direction, and the notch 35 (space) formed between the protrusions 20 exists. 9, the projection 20 is disposed between the substrate 3 and the ceiling member in a discontinuous state with respect to the direction of electricity flow.
[0043]
For example, an exhaust port 21 as an exhaust unit is provided at a lower portion of the chamber 1, and a gas and an etching product which do not participate in the reaction are exhausted from the exhaust port 21.
[0044]
In the above-described apparatus for producing a metal film, the source gas is supplied from the gas nozzle 12 into the chamber 1, and an electromagnetic wave is incident on the interior of the chamber 1 from the plasma antenna 9.₂The gas is ionized to Cl₂Gas plasma (source gas plasma) 14 (cleaning gas plasma) is generated.
[0045]
A member 18 to be etched, which is a conductor, is present below the plasma antenna 9, but Cl is formed between the member 18 to be etched and the substrate 3, that is, below the member 18 to be etched by the following operation.₂The gas plasma 14 is generated stably.
[0046]
Cl is applied to the member to be etched 18 below.₂The operation of generating the gas plasma 14 will be described. As shown in FIG. 3, the flow A of electricity of the planar ring-shaped plasma antenna 9 crosses the projection 20, and at this time, an induced current b is generated on the surface of the projection 20 facing the plasma antenna 9. . Since the notched portion 35 (space) exists in the member to be etched 18, the induced current b flows on the lower surface of each protrusion 20, and flows in the same direction as the electric current A of the plasma antenna 9. The flow becomes a (Faraday shield).
[0047]
Therefore, when the member 18 to be etched is viewed from the substrate 3 side, there is no flow in the direction to cancel the electric flow A of the plasma antenna 9, and furthermore, the ring portion 19 is grounded and the projection portion 20 has the same shape. Maintained at potential. As a result, even when the member to be etched 18 which is a conductor is present, an electromagnetic wave is reliably incident on the chamber 1 from the plasma antenna 9, and Cl is formed below the member to be etched 18.₂The gas plasma 14 is generated stably.
[0048]
It is also possible to eliminate the instability of the plasma due to the difference in potential by controlling the supply of the source gas without connecting the projection 20 to the ring 19.
[0049]
Cl₂The gas plasma 14 causes an etching reaction in the copper member 18 to be etched, and a precursor (CuxCly) 15 is generated. At this time, the member to be etched 18 is Cl₂The gas plasma 14 is maintained at a predetermined temperature (for example, 200 ° C. to 400 ° C.) higher than the temperature of the substrate 3. The precursor (CuxCly) 15 generated inside the chamber 1 is transferred to the substrate 3 controlled at a lower temperature than the member 18 to be etched. The precursor (CuxCly) 15 carried to the substrate 3 is converted into only Cu ions by a reduction reaction and applied to the substrate 3, and a Cu thin film 16 is generated on the surface of the substrate 3.
[0050]
The reaction at this time can be represented by the following equation.
2Cu + Cl₂→ 2CuCl → 2Cu ↓ + Cl₂↑
Gases not involved in the reaction and etching products are exhausted from the exhaust port 21.
[0051]
As a source gas, Cl diluted with He, Ar, or the like was used.₂The gas has been described as an example.₂It is also possible to use the gas alone or to use HCl gas. When HCl gas is applied, HCl gas plasma is generated as the source gas plasma, but the precursor generated by etching the member to be etched 18 is CuxCly. Therefore, the raw material gas may be any gas containing chlorine, and HCl gas and Cl₂It is also possible to use a mixed gas with a gas.
[0052]
The material of the member to be etched 18 is not limited to copper (Cu), but may be a halide-forming metal, preferably a chloride-forming metal such as Ag, Au, Pt, Ta, Ti, and W. . In this case, the precursor becomes a halide (chloride) such as Ag, Au, Pt, Ta, Ti, and W, and the thin film formed on the surface of the substrate 3 becomes Ag, Au, Pt, Ta, Ti, W, and the like. Become.
[0053]
The metal film manufacturing apparatus having the above-described configuration includes Cl₂Since the gas plasma (source gas plasma) 14 is used, the reaction efficiency is greatly improved and the film forming speed is increased. Further, Cl is used as a source gas.₂Since gas is used, the cost can be significantly reduced. Further, since the temperature of the substrate 3 is controlled to be lower than the temperature of the member to be etched 18 by using the temperature control means 6, the residual of impurities such as chlorine in the Cu thin film 16 can be reduced, and a high quality Cu thin film can be obtained. 16 can be generated.
[0054]
The member to be etched 18 is provided with a plurality of protrusions 20 on the inner peripheral side of the ring portion 19 in the circumferential direction, and the notch 35 (space) formed between the protrusions 20 exists. The induced current generated in the member to be etched 18 flows in the same direction as the electric flow of the plasma antenna 9 when viewed from the substrate 3 side.
[0055]
As a result, even if the member to be etched 18 that is a conductor is present below the plasma antenna 9, the electromagnetic wave from the plasma antenna 9 reliably enters the chamber 1, and Cl is placed below the member to be etched 18.₂The gas plasma 14 can be generated stably.
[0056]
In the above-described metal film manufacturing apparatus, in the film forming process, depending on the film forming conditions, CuCl is also adsorbed on the member to be etched 18 and solidified to form a CuCl film. When such a phenomenon is repeated and, for example, the entire region of the surface of the member to be etched formed of Cu is covered with CuCl, Cl₂The etching reaction on the member to be etched 18 by the gas plasma 14 does not proceed.
[0057]
Therefore, in the above-described metal film manufacturing apparatus, so-called cleaning, in which Cl is removed from the CuCl film adhering to the surface of the member to be etched 18 in each film forming step or after a predetermined number of film forming steps, is performed in the film forming step. Is done.
[0058]
When the cleaning is performed, the inside of the chamber 1 is controlled to a high pressure different from the film formation by the vacuum device 8, the plasma antenna 9 is energized, and the chlorine concentration is made higher than the source gas by the control of the flow rate control device 13. Gas is supplied from the gas nozzle 12 into the chamber 1.
[0059]
Thereby, Cl₂Gas plasma (cleaning gas plasma) is generated. Cl₂Gas plasma Cl^*CuCl (ad) adsorbed on the surface of the member 18 to be etched is etched by₂And Cu remains on the surface of the member 18 to be etched.
The reaction at this time is
CuCl (ad) + Cl^*→ Cu + Cl₂↑
Can be represented by
[0060]
Therefore, even if CuCl is adsorbed on the surface of the member 18 to be etched, Cl₂Generate gas plasma (cleaning gas plasma) to generate Cl^*To Cl₂As a result, CuCl adhering to the surface of the member to be etched 18 becomes Cu, and the surface of the member 18 to be etched can be uniformly cleaned. For this reason, the cleaning operation of the member to be etched 18 in the metal film forming apparatus can be performed easily and with high efficiency, and it is possible to obtain film forming characteristics with good reproducibility.
[0061]
In addition, since the cleaning gas is supplied to the position where the cleaning gas reaches the member to be etched 18 after being turned into plasma by the cleaning gas plasma generating means, the cleaning gas is supplied as raw gas (not turned into plasma) at the time of cleaning. The gas does not contact the member to be etched 18 and CuCl (s) is not generated on the surface. Therefore, the surface of the member to be etched 18 can be efficiently cleaned.
[0062]
Incidentally, when CuCl (s) is generated on the surface, Cl₂Gas plasma Cl^*By CuCl₂(S), it becomes difficult to remove Cl from the surface of the member 18 to be etched.
[0063]
Further, since the cleaning gas has a higher chlorine concentration than the source gas, the cleaning gas has a higher chlorine concentration.₂Gas plasma Cl^*And Cl can be efficiently removed from the surface of the member 18 to be etched.
[0064]
The second embodiment will be described with reference to FIG.
[0065]
FIG. 4 shows a schematic side view of a metal film manufacturing apparatus according to a second embodiment of the present invention. The same members (same functional members) as the members shown in FIGS. 1 to 3 are denoted by the same reference numerals, and redundant description is omitted.
[0066]
As shown in FIG. 4, a bias power supply 23 which is a DC power supply is connected to the member to be etched 18, and the member to be etched 18 is deflected to a negative potential by the bias power supply 23. The bias power supply 23 is connected to the member to be etched 18 made of copper by the switch means 24, and positively biases the member to be etched 18 to a negative potential only at the time of cleaning, for example.
[0067]
By displacing the member to be etched 18 to a negative potential, Cl₂Positive ions in the gas plasma are electrically attracted to the member to be etched 18, and the CuCl adsorbed on the surface by the collision energy can be physically etched, and the etching reaction at the time of cleaning can be promoted.
[0068]
It is also possible to omit the switch means 24 and to shift the member to be etched 18 to a negative potential by the bias power source 23 even when etching the member to be etched 18 at the time of film formation, thereby promoting the etching at the time of film formation. It is.
[0069]
Since the chamber 1 is made of metal, the member 18 to be etched and the chamber 1 are insulated when the bias power supply 23 is connected. That is, the portion of the chamber 1 that holds the member to be etched 18 is formed by the insulating cylinder 31.
[0070]
Therefore, in the metal film manufacturing apparatus and the cleaning method of the second embodiment, in addition to the second embodiment, the etching reaction at the time of cleaning can be promoted, and the member to be etched 18 can be more efficiently cleaned. Becomes possible.
[0071]
A third embodiment will be described with reference to FIG.
[0072]
FIG. 5 shows a schematic side view of a metal film manufacturing apparatus according to a third embodiment of the present invention. The same members as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.
[0073]
As shown in the figure, a support 2 is provided in the vicinity of the bottom of a chamber 1 made of, for example, a ceramic (made of an insulating material), and a substrate 3 is placed on the support 2. You. The support 2 is provided with a temperature controller 6 having a heater 4 and a coolant circulating means 5. The support 2 is controlled by the temperature controller 6 to a predetermined temperature (for example, a temperature at which the substrate 3 is maintained at 100 to 200 ° C.). ) Is controlled.
[0074]
The upper surface of the chamber 1 is an opening, and the opening is closed by a metal member (ceiling plate) 25 as a metal member to be etched. The inside of the chamber 1 closed by the ceiling plate 25 is maintained at a predetermined pressure by the vacuum device 8.
[0075]
A gas nozzle 12 serving as a source gas supply unit and a cleaning gas supply unit is provided around the support base 2 inside the chamber 1, and the gas nozzle 12 is provided with a source gas containing chlorine as a halogen via a flow rate control device 13. Cl diluted with He, Ar, etc. to a chlorine concentration of ≤50% ５０, preferably about 10% 等₂Gas) and a cleaning gas containing chlorine as a halogen (He, Ar, etc.), wherein the chlorine concentration is made higher than that of the raw material gas, and the Cl is diluted to about 30%.₂Gas), and a raw material gas and a cleaning gas are supplied from the gas nozzle 12 into the chamber 1.
[0076]
It is also possible to make the halogen concentration of the cleaning gas the same as the halogen concentration of the source gas and omit the control of the dilution concentration.
[0077]
Switching between the source gas and the cleaning gas (changing the concentration) is performed by the flow controller 13 during cleaning with Cl as halogen.₂This is performed by increasing the amount of gas relatively. The cleaning gas supply means may be provided independently of the source gas supply means, that is, a nozzle for exclusively supplying the cleaning gas may be provided.
[0078]
The raw material gas is supplied from the gas nozzle 12 toward the ceiling plate 25 at an angle of, for example, 45 degrees. As the halogen contained in the source gas, fluorine (F), bromine (Br), iodine (I), or the like can be used.
[0079]
A cylindrical coil-shaped plasma antenna 26 is provided on the outer circumference of the cylindrical portion of the chamber 1, and the plasma antenna 26 is connected to a matching unit 10 and a power supply 11 as a plasma generation unit and a cleaning gas plasma generation unit to supply power. .
[0080]
The raw material gas and the cleaning gas are supplied from the gas nozzle 12 toward the ceiling plate 25 at an angle of, for example, 45 degrees. That is, the cleaning gas is supplied to the position where the cleaning gas reaches the member to be etched 18 after being turned into plasma by the cleaning gas plasma generating means.
[0081]
In the above-described apparatus for producing a metal film, the material gas is supplied from the gas nozzle 12 into the chamber 1, and an electromagnetic wave is incident on the interior of the chamber 1 from the plasma antenna 26.₂The gas is ionized to Cl₂Gas plasma (source gas plasma) 14 is generated. Cl₂The gas plasma 14 causes an etching reaction on the copper ceiling plate 25 to generate a precursor (CuxCly) 15. At this time, the ceiling plate 25 is₂The gas plasma 14 is maintained at a predetermined temperature (for example, 200 ° C. to 400 ° C.) higher than the temperature of the substrate 3.
[0082]
The precursor (CuxCly) 15 generated inside the chamber 1 is transferred to the substrate 3 controlled at a lower temperature than the ceiling plate 25. The precursor (CuxCly) 15 carried to the substrate 3 is converted into only Cu ions by a reduction reaction and applied to the substrate 3, and a Cu thin film 16 is generated on the surface of the substrate 3.
[0083]
The reaction at this time can be represented by the following equation.
2Cu + Cl₂→ 2CuCl → 2Cu ↓ + Cl₂↑
Gases not involved in the reaction and etching products are exhausted from the exhaust port 21.
[0084]
As a source gas, Cl diluted with He, Ar, or the like was used.₂The gas has been described as an example.₂It is also possible to use the gas alone or to use HCl gas. When HCl gas is applied, HCl gas plasma is generated as the source gas plasma, but the precursor generated by etching the metal member 47 is CuxCly. Therefore, the raw material gas may be any gas containing chlorine, and HCl gas and Cl₂It is also possible to use a mixed gas with a gas.
[0085]
The material of the metal member 47 is not limited to copper (Cu), but may be a halide-forming metal, preferably a chloride-forming metal such as Ag, Au, Pt, Ta, Ti, and W. In this case, the precursor becomes a halide (chloride) such as Ag, Au, Pt, Ta, Ti, and W, and the thin film formed on the surface of the substrate 3 becomes Ag, Au, Pt, Ta, Ti, W, and the like. Become.
[0086]
The metal film manufacturing apparatus having the above-described configuration includes Cl₂Since the gas plasma (source gas plasma) 14 is used, the reaction efficiency is greatly improved and the film forming speed is increased. Further, Cl is used as a source gas.₂Since gas is used, the cost can be significantly reduced. In addition, since the temperature of the substrate 3 is controlled to be lower than that of the ceiling plate 25 by using the temperature control means 6, the residual of impurities such as chlorine in the Cu thin film 16 can be reduced. Can be generated.
[0087]
In the above-described metal film manufacturing apparatus, in the film forming process, depending on the film forming conditions, CuCl is also adsorbed on the ceiling plate 25 and solidified to form a CuCl film. Such a phenomenon is repeated, for example, when the entire surface of the ceiling plate 25 formed of Cu is covered with CuCl, Cl₂The etching reaction on the ceiling plate 25 by the gas plasma 14 does not proceed.
[0088]
Therefore, in the above-described metal film manufacturing apparatus, so-called cleaning is performed, in which Cl is removed from the CuCl film adhering to the surface of the ceiling plate 25 in each film forming step or after a predetermined number of film forming steps in the film forming step. You.
[0089]
When cleaning is performed, the inside of the chamber 1 is controlled to a high pressure different from the film formation by the vacuum device 8, the plasma antenna 26 is energized, and the cleaning is performed by controlling the flow rate control device 13 so that the chlorine concentration is higher than the source gas. Gas is supplied from the gas nozzle 12 into the chamber 1.
[0090]
Thereby, Cl₂Gas plasma (cleaning gas plasma) is generated. Cl₂Gas plasma Cl^*CuCl (ad) adsorbed on the surface of the ceiling plate 25 is etched by the₂And Cu remains on the surface of the ceiling plate 25.
The reaction at this time is
CuCl (ad) + Cl^*→ Cu + Cl₂↑
Can be represented by
[0091]
Therefore, even if CuCl is adsorbed on the surface of the ceiling plate 25, Cl₂Generate gas plasma (cleaning gas plasma) to generate Cl^*To Cl₂As a result, CuCl adhering to the surface of the ceiling plate 25 is converted into Cu, and the surface of the ceiling plate 25 can be uniformly cleaned. Therefore, the work of cleaning the ceiling plate 25 in the metal film forming apparatus can be performed easily and with high efficiency, and it is possible to obtain film forming characteristics with good reproducibility.
[0092]
Since the cleaning gas is supplied to the ceiling plate 25 after being turned into plasma by the cleaning gas plasma generating means, the cleaning gas is supplied as raw gas (gas not converted to plasma) at the time of cleaning. ) Does not contact the ceiling plate 25 to generate CuCl (s) on the surface. Therefore, the surface of the ceiling plate 25 can be efficiently cleaned.
[0093]
Incidentally, when CuCl (s) is generated on the surface, Cl₂Gas plasma Cl^*Changes CuCl (s) on the surface to CuCl₂(S), it becomes difficult to remove Cl from the surface of the ceiling plate 25.
[0094]
Further, since the cleaning gas has a higher chlorine concentration than the source gas, the cleaning gas has a higher chlorine concentration.₂Gas plasma Cl^*, And Cl can be efficiently removed from the surface of the ceiling plate 25.
[0095]
A fourth embodiment will be described based on FIG.
[0096]
FIG. 6 shows a schematic side view of a metal film manufacturing apparatus according to a fourth embodiment of the present invention. Note that the same members as those of the metal film manufacturing apparatus shown in FIGS. 1 to 5 are denoted by the same reference numerals, and redundant description is omitted.
[0097]
The metal film forming apparatus according to the fourth embodiment shown in FIG. 6 is different from the metal film forming apparatus shown in FIG. 5 in that the plasma antenna 26 is not provided around the cylindrical portion of the chamber 1 and the ceiling plate The matching device 10 and the power supply 11 are connected to the power supply 25, power is supplied to the ceiling plate 25, and the support 2 is grounded (plasma generating means and cleaning gas plasma generating means).
[0098]
In the above-described metal film forming apparatus, the source gas is supplied from the gas nozzle 12 to the inside of the chamber 1, and the electromagnetic wave is incident on the inside of the chamber 1 from the ceiling plate 25, whereby Cl₂The gas is ionized to Cl₂Gas plasma (source gas plasma) 14 is generated. Cl₂The gas plasma 14 causes an etching reaction on the copper ceiling plate 25 to generate a precursor (CuxCly) 15. At this time, the ceiling plate 25 is₂The temperature is maintained at a predetermined temperature (for example, 200 ° C. to 400 ° C.) higher than the temperature of the substrate 3 by the gas plasma 14 (or temperature control means not shown).
[0099]
The precursor (CuxCly) 15 generated inside the chamber 1 is transferred to the substrate 3 controlled at a lower temperature than the ceiling plate 25. The precursor (CuxCly) 15 carried to the substrate 3 is converted into only Cu ions by a reduction reaction and applied to the substrate 3, and a Cu thin film 16 is generated on the surface of the substrate 3. Gases not involved in the reaction and etching products are exhausted from the exhaust port 21.
[0100]
In the above-described metal film manufacturing apparatus, since the metal member 47 itself is used as an electrode for plasma generation, members such as the plasma antenna 49 are not required around the cylindrical portion of the chamber 41, and the degree of freedom of the surrounding configuration is reduced. Can increase.
[0101]
In the above-described metal film manufacturing apparatus, in the film forming process, depending on the film forming conditions, CuCl is also adsorbed on the ceiling plate 25 and solidified to form a CuCl film. Such a phenomenon is repeated, for example, when the entire surface of the ceiling plate 25 formed of Cu is covered with CuCl, Cl₂The etching reaction on the ceiling plate 25 by the gas plasma 14 does not proceed.
[0102]
Therefore, in the above-described metal film manufacturing apparatus, so-called cleaning is performed, in which Cl is removed from the CuCl film adhering to the surface of the ceiling plate 25 in each film forming step or after a predetermined number of film forming steps in the film forming step. You.
[0103]
When cleaning is performed, the inside of the chamber 1 is controlled to a high pressure different from the film formation by the vacuum device 8, the ceiling plate 25 is energized, and the chlorine concentration is made higher than the source gas by the control of the flow rate control device 13. Gas is supplied from the gas nozzle 12 into the chamber 1.
[0104]
Thereby, Cl₂Gas plasma (cleaning gas plasma) is generated. Cl₂Gas plasma Cl^*CuCl (ad) adsorbed on the surface of the ceiling plate 25 is etched by the₂And Cu remains on the surface of the ceiling plate 25.
The reaction at this time is
CuCl (ad) + Cl^*→ Cu + Cl₂↑
Can be represented by
[0105]
Therefore, even if CuCl is adsorbed on the surface of the ceiling plate 25, Cl₂Generate gas plasma (cleaning gas plasma) to generate Cl^*To Cl₂As a result, CuCl adhering to the surface of the ceiling plate 25 is converted into Cu, and the surface of the ceiling plate 25 can be uniformly cleaned. Therefore, the work of cleaning the ceiling plate 25 in the metal film forming apparatus can be performed easily and with high efficiency, and it is possible to obtain film forming characteristics with good reproducibility.
[0106]
Further, the cleaning gas is supplied to the position where the cleaning gas reaches the ceiling plate 25 after being turned into plasma by the cleaning gas plasma generating means. ) Does not contact the ceiling plate 25 to generate CuCl (s) on the surface. Therefore, the surface of the ceiling plate 25 can be efficiently cleaned.
[0107]
Incidentally, when CuCl (s) is generated on the surface, Cl₂Gas plasma Cl^*Changes CuCl (s) on the surface to CuCl₂(S), it becomes difficult to remove Cl from the surface of the ceiling plate 25.
[0108]
Further, since the cleaning gas has a higher chlorine concentration than the source gas, the cleaning gas has a higher chlorine concentration.₂Gas plasma Cl^*, And Cl can be efficiently removed from the surface of the ceiling plate 25.
[0109]
A fifth embodiment will be described with reference to FIG.
[0110]
FIG. 7 shows a schematic side view of a metal film manufacturing apparatus according to a fifth embodiment of the present invention. Note that the same members as those of the metal film manufacturing apparatus shown in FIGS. 1 to 6 are denoted by the same reference numerals, and redundant description is omitted.
[0111]
In the metal film manufacturing apparatus according to the sixth embodiment shown in FIG. 7, the upper surface of the chamber 1 has an opening, and the opening is closed by a ceiling plate 7 made of, for example, ceramic (insulating material). A member 41 to be etched made of metal (copper: Cu) is provided on the lower surface of the ceiling plate 7, and the member 41 to be etched has, for example, a quadrangular pyramid shape. A slit-shaped opening 42 is formed around the cylindrical portion of the chamber 1, and one end of a cylindrical passage 43 is fixed to the opening 41.
[0112]
A cylindrical excitation chamber 44 made of an insulator is provided in the middle of the passage 43, and a coil-shaped plasma antenna 45 is provided around the excitation chamber 44. The plasma antenna 45 is a plasma generation unit and a cleaning gas plasma generation. Power is supplied by being connected to the matching unit 10 and the power supply 11 as means. The flow control device 13 is connected to the other end of the passage 43, and the source gas and the cleaning gas are supplied into the passage 43 via the flow control device 13.
[0113]
The source gas and the cleaning gas are the same as those in the first to fourth embodiments.
[0114]
When an electromagnetic wave enters the inside of the excitation chamber 44 from the plasma antenna 45, Cl₂The gas is ionized to Cl₂Gas plasma (source gas plasma or cleaning gas plasma) 46 is generated. That is, the source gas and the cleaning gas are excited in the excitation chamber 46 separated from the chamber 1. Cl₂Excited chlorine is sent from the opening 42 into the chamber 1 by the generation of the gas plasma 35, and the member 41 to be etched is etched by the excited chlorine.
[0115]
In the above-described metal film forming apparatus, the source gas is supplied into the passage 43 via the flow rate control device 13 and is sent to the excitation chamber 44. When an electromagnetic wave enters the inside of the excitation chamber 44 from the plasma antenna 45, Cl₂The gas is ionized to Cl₂Gas plasma (source gas plasma) 35 is generated. Since a predetermined pressure difference between the pressure in the chamber 1 and the pressure in the excitation chamber 44 is set by the vacuum device 8, the Cl in the excitation chamber 44 is₂The excited chlorine of the gas plasma 35 is sent from the opening 42 to the member 41 to be etched in the chamber 1. An etching reaction occurs in the member to be etched 41 due to the excited chlorine, and a precursor (CuxCly) 15 is generated inside the chamber 1.
[0116]
The precursor (CuxCly) 15 generated inside the chamber 1 is transported to the substrate 3, and the precursor (CuxCly) 15 transported to the substrate 3 is reduced to only Cu ions and applied to the substrate 3. Is formed on the surface of the substrate. Gases not involved in the reaction and etching products are exhausted from the exhaust port 21.
[0117]
In the metal film manufacturing apparatus shown in FIG. 7, the source gas plasma 46 is generated in the excitation chamber 44 isolated from the chamber 1, so that the substrate 3 is not exposed to the plasma, and the substrate 3 is damaged by the plasma. Does not occur. For example, in the case of the substrate 3 on which a film of a different material is formed in the previous step, the film of the material formed in the previous step is not damaged.
[0118]
In the excitation chamber 44, Cl₂As a means (excitation means) for generating the gas plasma 46, a microwave, a laser, an electron beam, radiation light, or the like can be used. Further, in the metal film manufacturing apparatus shown in FIG. 7, since no plasma is generated in the chamber 1, there is no need to supply a rare gas to stabilize the plasma in the chamber 1.
[0119]
In the metal film manufacturing apparatus described above, in the film forming step, depending on the film forming conditions, CuCl is also adsorbed on the member 41 to be etched, and is solidified to form a CuCl film. When such a phenomenon is repeated and the entire surface of the member to be etched 41 made of Cu is covered with CuCl, for example, the etching reaction of the member to be etched 41 by the excited chlorine does not proceed.
[0120]
Therefore, in the above-described metal film manufacturing apparatus, so-called cleaning, in which Cl is removed from the CuCl film adhering to the surface of the member to be etched 41 in each film forming step or after a predetermined number of film forming steps, is performed. Is done.
[0121]
When the cleaning is performed, the inside of the chamber 1 is controlled to a high pressure different from the film formation by the vacuum device 8, the plasma antenna 45 is energized, and the flow rate control device 13 controls the cleaning so that the chlorine concentration is higher than the source gas. Gas is supplied into the excitation chamber 44.
[0122]
Thereby, Cl is introduced into the excitation chamber 44.₂Gas plasma (cleaning gas plasma) is generated and Cl₂Excited chlorine of the gas plasma is sent from the opening 42 to the member 41 to be etched in the chamber 1. Excited chlorine Cl^*CuCl (ad) adsorbed on the surface of the member 41 to be etched is etched by₂And Cu remains on the surface of the member 41 to be etched.
The reaction at this time is
CuCl (ad) + Cl^*→ Cu + Cl₂↑
Can be represented by
[0123]
Therefore, even if CuCl is adsorbed on the surface of the member 41 to be etched, Cl₂A gas plasma (cleaning gas plasma) is generated and the excited chlorine is sent to the chamber 1,^*To Cl₂As a result, CuCl adhering to the surface of the member to be etched 41 is converted into Cu, and the surface of the member to be etched 41 can be uniformly cleaned. For this reason, the cleaning operation of the member to be etched 41 in the metal film forming apparatus can be performed easily and with high efficiency, and it is possible to obtain film forming characteristics with good reproducibility.
[0124]
Further, since the cleaning gas has a higher chlorine concentration than the source gas, the cleaning gas has a higher chlorine concentration.₂Gas plasma Cl^*, And Cl can be efficiently removed from the surface of the member 41 to be etched.
[0125]
【The invention's effect】
The metal film manufacturing apparatus of the present invention includes a chamber in which a substrate is housed, a metal member to be etched disposed in the chamber, a source gas supply unit for supplying a source gas containing halogen, and a source gas plasma. Plasma generating means for generating a precursor of a metal component and a raw material gas contained in the member to be etched by etching the member to be etched, and a precursor having a substrate side temperature lower than the member side to be etched. Temperature control means for forming a film of the metal component on the substrate, cleaning gas supply means for supplying a cleaning gas containing halogen, and a surface of the member to be etched by generating a cleaning gas plasma and etching the surface of the member to be etched. Cleaning gas plasma generating means for removing halogen adhering to The cleaning gas plasma when the components are attached to the etched member by etching the surface of the etched member, it is possible to remove the component of the halogen precursor.
[0126]
As a result, the surface of the member to be etched can be efficiently and completely cleaned, the cleaning operation of the member to be etched in the metal film forming apparatus can be performed easily and with high efficiency, and the film forming characteristics with good reproducibility. Can be obtained.
[0127]
And a cleaning gas supply means for supplying the cleaning gas to the member to be etched after the supplied cleaning gas is turned into cleaning gas plasma by the cleaning gas plasma generating means. Is supplied, so that the cleaning gas does not come into contact with the member to be etched without being turned into plasma.
[0128]
Further, in the metal film forming apparatus according to claim 1 or 2, the cleaning gas supply unit supplies a cleaning gas having a halogen concentration higher than the halogen concentration of the source gas supplied from the source gas supply unit. Many halogen radicals in the cleaning gas plasma can be secured.
[0129]
Further, in the metal film forming apparatus according to any one of claims 1 to 3, a bias for shifting the potential of the member to be etched to the negative side when the cleaning gas plasma is generated by the cleaning gas plasma generating means. Since the power supply is provided, positive ions of the cleaning gas plasma can be electrically drawn into the member to be etched, and the etching can be promoted.
[0130]
Further, in the metal film forming apparatus according to any one of claims 1 to 4, the halogen-containing source gas and the cleaning gas are chlorine-containing source gas and a cleaning gas, and Is composed of the same supply system as the raw material gas supply means, so that a simple configuration can be achieved using inexpensive gas.
[0131]
In the metal film manufacturing apparatus according to the fifth aspect, since the member to be etched is made of copper, CuxCly is generated as a precursor, so that the present invention can be applied to copper film formation.
[0132]
Further, in the metal film manufacturing apparatus according to any one of claims 1 to 6, the member to be etched is tantalum, tungsten, or titanium which is a halide forming metal. Can be applied to membranes.
[0133]
In the cleaning method of the present invention, a member to be etched formed of a metal for forming a high vapor pressure halide disposed inside a chamber is etched with a plasma of a source gas containing halogen to form a predetermined metal film on a substrate. In the cleaning method of the metal film forming apparatus to be formed, the surface of the member to be etched is etched by a cleaning gas plasma containing halogen to remove the halogen adhered to the surface of the member to be etched. By etching the surface of the member to be etched with the cleaning gas plasma when it adheres to the surface, the halogen component of the precursor can be removed.
[0134]
As a result, it is possible to efficiently and completely clean the surface of the member to be etched, and it is possible to obtain film characteristics with good reproducibility.
[0135]
In the cleaning method according to the eighth aspect, since the cleaning gas plasma is supplied toward the member to be etched, the cleaning gas does not directly contact the member to be etched.
[0136]
Further, in the cleaning method according to claim 8 or 9, since the halogen concentration of the cleaning gas is higher than the halogen concentration of the source gas, it is possible to secure more halogen radicals in the cleaning gas plasma.
[0137]
Further, in the cleaning method according to any one of claims 8 to 10, the potential of the member to be etched is deviated to the negative side when the surface of the member to be etched is etched by the cleaning gas plasma. Positive ions of the gas plasma can be electrically drawn into the member to be etched, and the etching can be promoted.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a metal film manufacturing apparatus according to a first embodiment of the present invention.
FIG. 2 is a view taken along line II-II in FIG.
FIG. 3 is a view taken along line III-III in FIG. 2;
FIG. 4 is a schematic side view of a metal film manufacturing apparatus according to a second embodiment of the present invention.
FIG. 5 is a schematic side view of a metal film manufacturing apparatus according to a third embodiment of the present invention.
FIG. 6 is a schematic configuration diagram of a metal film manufacturing apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a schematic configuration diagram of a metal film manufacturing apparatus according to a fifth embodiment of the present invention.
[Explanation of symbols]
1 chamber
2 support
3 substrate
4 heater
5 Refrigerant distribution means
6 Temperature control means
7 ceiling board
8 mm vacuum equipment
9,26,45 ° plasma antenna
10 ° matching device
11 power supply
12mm gas nozzle
13 Flow control device
14,46 Cl₂Gas plasma
16 Cu thin film
18, 41 Member to be etched
19mm ring
20mm protrusion
21mm exhaust port
23 bias power supply
24 switch means
25 ceiling board
26 plasma antenna
31 insulating cylinder
35 ° notch
42mm opening
43 passage
44 ° excitation chamber

Claims (11)

A chamber for accommodating the substrate;
A member to be etched made of metal disposed in the chamber;
Source gas supply means for supplying a source gas containing halogen,
Plasma generation 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 and etching the member to be etched,
Temperature control means for lowering the temperature on the substrate side to a temperature lower than the temperature on the member to be etched side and forming a metal component of the precursor on the substrate,
Cleaning gas supply means for supplying a cleaning gas containing halogen; and cleaning gas plasma generation means for generating cleaning gas plasma and etching the surface of the member to be etched to remove halogen attached to the surface of the member to be etched. An apparatus for producing a metal film, comprising: The metal film production apparatus according to claim 1,
The cleaning gas supply unit supplies the cleaning gas to a position where the supplied cleaning gas reaches the member to be etched after the cleaning gas is converted into cleaning gas plasma by the cleaning gas plasma generation unit. The metal film production apparatus according to claim 1 or 2,
An apparatus for producing a metal film, wherein the cleaning gas supply unit supplies a cleaning gas having a halogen concentration higher than the halogen concentration of the source gas supplied from the source gas supply unit. The metal film manufacturing apparatus according to any one of claims 1 to 3,
A metal film producing apparatus, comprising: a bias power supply for displacing the potential of a member to be etched to a negative side when a cleaning gas plasma is generated by a cleaning gas plasma generating means. The metal film manufacturing apparatus according to any one of claims 1 to 4,
The halogen-containing source gas and the cleaning gas are a chlorine-containing source gas and a cleaning gas,
An apparatus for producing a metal film, wherein the cleaning gas supply means comprises the same supply system as the source gas supply means. The metal film manufacturing apparatus according to claim 5,
An apparatus for producing a metal film, wherein CuxCly is generated as a precursor by forming a member to be etched from copper. In any one of claims 1 to 6,
A metal film forming apparatus, wherein the member to be etched is tantalum, tungsten or titanium which is a halide forming metal. A metal film forming apparatus for forming a predetermined metal film on a substrate by etching a member to be etched formed of a metal for forming a high vapor pressure halide disposed inside a chamber with a plasma of a source gas containing halogen. In the cleaning method,
A cleaning method, characterized in that the surface of a member to be etched is etched with a cleaning gas plasma containing halogen to remove halogen attached to the surface of the member to be etched. The cleaning method according to claim 8,
A cleaning method comprising supplying a cleaning gas plasma to a member to be etched. In the cleaning method according to claim 8 or 9,
A cleaning method, wherein the halogen concentration of the cleaning gas is higher than the halogen concentration of the source gas. In the cleaning method according to any one of claims 8 to 10,
A cleaning method, wherein the potential of a member to be etched is deviated to a negative side when the surface of the member to be etched is etched by a cleaning gas plasma.

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