JP2008078507A - Selective formation method of electric conductor and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to efficiently, selectively and easily provide an electric conductor inside a hole, a concave portion, a groove or the like which is fine and has a high aspect ratio by using supercritical fluid irrespective of a grounding material. <P>SOLUTION: While arranging under an atmosphere containing the supercritical fluid a processed body 16 in which a concave portion 15 providing an electric conductor 21 is formed and a metallic compound 18 containing a metal 20 which is used as a principal component of the electric conductor 21, at least a part of the metallic compound 18 is dissolved in the supercritical fluid. While contacting the metallic compound 18a dissolved in the supercritical fluid with a front surface of the processed body 16 and selectively introducing the metallic compound 18a into the concave portion 15, the metallic compound 18a introduced into the concave portion 15 is flocculated within the concave portion 15 to deposit the metal 20 from the metallic compound 18a. The electric conductor 21 is provided in the concave portion 15 by solidifying the metal 20 deposited within the concave portion 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for selectively providing a conductor at a predetermined position, and in particular, a conductor can be selectively provided using a supercritical fluid inside a hole, a concave portion, or a groove having a fine and high aspect ratio. The present invention relates to a method for selectively forming a conductor, and a method for manufacturing a semiconductor device in which fine wirings, plugs, electrodes, or the like can be provided using this method.

  In order to manufacture a microelectronic element such as an integrated circuit, there is a process of filling a metal inside a fine hole such as a wiring forming groove, a plug forming hole, or an electrode forming concave part with a fine and high aspect ratio without gaps. It is essential. Usually, in such a process, a metal thin film is deposited on the surface of a substrate or an insulating film in which pore openings are formed in advance, and the phenomenon that the metal thin film enters the pores from the openings. We are using. That is, a so-called damascene process embedding method in which a metal thin film is embedded in the pores is generally employed.

  However, in the conventional embedding method, since a metal thin film is deposited from above in the pores, voids are generated in the pores when penetration of the metal thin film into the pores is insufficient. On the contrary, if the penetration of the metal thin film into the pore is extremely small, the embedded wiring or the like may be disconnected. Further, in a general embedding method, it is sufficient to fill the inside of the pores with a metal, and a metal thin film outside the pores is unnecessary. For this reason, after the process of embedding the metal in the pores is completed, a process of removing the metal thin film deposited on the substrate or the insulating film by a CMP method or the like is necessary. That is, a general embedding method is not economical and has low efficiency because the film forming raw material is likely to be wasted and the number of steps is likely to increase. Such a problem can be solved if a technique capable of selectively filling metal into the pores is developed. One such technique is a so-called selective deposition method. And this selective deposition method is tried using CVD method, for example.

  However, the CVD method generally has a high process temperature including a film forming temperature, and is highly dependent on the process temperature. At the same time, the CVD method consumes a lot of raw materials and energy. For this reason, the CVD method has a small process margin. Further, the CVD method has a problem that impurities are easily mixed. Furthermore, since a metal film is formed by a CVD method, so-called metal CVD method uses base dependency, the material system of the film to be formed and the base layer is limited. In the metal CVD method, a metal film can be formed substantially only on a conductor such as metal. In particular, in the so-called organometallic CVD method using a liquid source, the liquid source is generally unstable and the process margin is smaller.

  Further, as a general thin film forming method other than the CVD method, there is a PVD method, but this PVD method has a problem that the step coverage is lower than that of the CVD method. For this reason, when a metal thin film is formed by the PVD method to embed the pores, there is a high risk of causing burying defects. As a result, there is a high risk of causing disconnection of embedded wiring or the like. Note that the PVD method cannot perform the selective deposition method because of its principle. Furthermore, the PVD method and the CVD method have a problem that the throughput is slow because the process density is low.

  Furthermore, in recent years, various electronic devices including semiconductor devices have been further miniaturized. Accordingly, further miniaturization and higher integration of microelectronic elements such as integrated circuits are remarkable. In a miniaturized integrated circuit, the structure of its internal wiring, plugs, electrodes, etc. is more complicated, three-dimensional, or thinner than the previous one. In order to efficiently form wiring, plugs, or electrodes having such a structure, for example, a technique capable of efficiently forming so-called vertical nanowirings is essential. That is, in order to manufacture an integrated circuit with further miniaturization, there is no gap between the metal inside the fine and high aspect ratio wiring forming grooves, plug forming holes, or electrode forming recesses, and A technique that enables efficient filling is essential.

However, as described above, the conventional damascene method or subtract method using the CVD method or the PVD method is likely to be complicated in the process, and it is difficult to reduce the number of processes. For this reason, production efficiency is low and it is difficult to suppress production costs. In addition, the limits of embedding and filling properties are beginning to appear. In other words, with the conventional pore filling technique, it is expected that it will be extremely difficult to follow further miniaturization and higher integration of the integrated circuit. In order to solve such problems of conventional pore embedding techniques, recently, a so-called supercritical chemical deposition method, in which a microporous film is selectively embedded by forming a metal film using a supercritical fluid. Techniques have been proposed (for example, see Non-Patent Documents 1 and 2).
Clean Technology 2004.4 Nippon Kogyo Publishing (2004), 55-58 pages Semiconductor FPD World 2004.8, p.44-47

  The supercritical method described above has just begun research and development, and has not yet reached a practical stage that can withstand the process of manufacturing integrated circuits and semiconductor devices as actual products.

  The present invention has been made in order to solve the problems described above, and the object of the present invention is to provide fine, high aspect ratio holes, recesses, grooves, or the like regardless of the material of the base. An object of the present invention is to provide a method for selectively forming a conductor, which can efficiently and selectively provide a conductor using a supercritical fluid. In addition, it is an object of the present invention to provide a method for manufacturing a semiconductor device in which fine wirings, plugs, electrodes, or the like can be efficiently and easily provided using such a method for selectively forming a conductor.

  In order to solve the above problems, a method for selectively forming a conductor according to one embodiment of the present invention includes a target object in which a recess for providing a conductor is formed and a metal compound including a metal that is a main component of the conductor. It is arranged in an atmosphere containing a supercritical fluid, and at least a part of the metal compound is dissolved in the supercritical fluid, and the metal compound dissolved in the supercritical fluid is brought into contact with the surface of the object to be processed. Selectively introducing into the recess, and aggregating the metal compound introduced into the recess in the recess to precipitate the metal from the metal compound, thereby removing the supercritical fluid from the atmosphere. And the said conductor is provided in the said recessed part by solidifying the said metal which precipitated in the said recessed part, It is characterized by the above-mentioned.

  In this method of selectively forming an electric conductor, a metal compound containing a metal as a main component of an electric conductor provided in a recess formed in an object to be processed is dissolved in a supercritical fluid and is rich in fluidity. To make contact with the surface of the object. As a result, the metal compound can smoothly flow on the surface of the object to be processed, and can be selectively introduced in a self-aligned manner into the recess having a structure lower than the surface of the object to be processed. In addition, the metal compound dissolved in the supercritical fluid is introduced into the recess sequentially from the bottom to the top without creating a cavity inside even if the recess is fine and the aspect ratio is high due to its fluidity. Is done. Further, the metal compound dissolved in the supercritical fluid flows in a self-aligned manner and selectively into the recess from the surface of the object to be processed regardless of the material of the inner surface of the recess. As a result, the metal that is the main component of the conductor is deposited and solidified in a self-aligned manner and selectively in the recess, regardless of the material of the underlying layer. Therefore, according to the method for selectively forming an electric conductor according to one embodiment of the present invention, the electric conductor can be efficiently and selectively contained in a hole, a recess, a groove, or the like that is fine and has a high aspect ratio regardless of the material of the base. And can be provided easily.

  In order to solve the above problems, a method of manufacturing a semiconductor device according to another aspect of the present invention includes a recess in which a conductor is provided on at least one of a substrate body and an insulating film provided above the substrate body. And a metal compound containing a metal that is a main component of the conductor is placed in an atmosphere containing a supercritical fluid, and at least a part of the metal compound is placed in the supercritical fluid. The metal compound dissolved and dissolved in the supercritical fluid is brought into contact with the surface of the semiconductor substrate and selectively introduced into the recess, and the metal compound introduced into the recess is introduced into the recess. The conductor is provided in the recess by agglomerating to deposit the metal from the metal compound and solidifying the metal deposited in the recess. .

  In this method of manufacturing a semiconductor device, a metal containing a metal as a main component of a conductor provided in a recess formed in at least one of a substrate body of a semiconductor substrate and an insulating film provided above the substrate body The compound is dissolved in a supercritical fluid and brought into contact with the surface of the semiconductor substrate in a state where the compound is rich in fluidity. As a result, the metal compound can be smoothly introduced on the surface of the semiconductor substrate and can be selectively introduced in a self-aligned manner into the recess having a structure lower than the surface of the semiconductor substrate. In addition, the metal compound dissolved in the supercritical fluid is introduced into the recess sequentially from the bottom to the top without creating a cavity inside even if the recess is fine and the aspect ratio is high due to its fluidity. Is done. Further, the metal compound dissolved in the supercritical fluid flows selectively into the recess from the surface of the semiconductor substrate in a self-aligned manner regardless of the material of the inner surface of the recess. As a result, the metal that is the main component of the conductor is deposited and solidified in a self-aligned manner and selectively in the recess, regardless of the material of the underlying layer. Therefore, according to the method for manufacturing a semiconductor device according to another aspect of the present invention, fine wirings, plugs, electrodes, or the like can be provided efficiently and easily.

  According to the method for selectively forming a metal body according to an aspect of the present invention, the metal body can be efficiently formed using a supercritical fluid inside a hole, a concave portion, or a groove having a high aspect ratio regardless of the material of the base. It can be provided selectively and easily.

  In addition, according to the method for manufacturing a semiconductor device according to another aspect of the present invention, wiring, plugs, electrodes, or the like can be efficiently and easily provided using the metal body selective formation method according to the present invention. it can.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(First embodiment)
First, a first embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram schematically showing a conductor selective forming apparatus according to the present embodiment. FIG. 2 is a simplified cross-sectional view showing the inside of the reaction vessel provided in the conductor selective forming apparatus shown in FIG. FIG. 3 is a diagram schematically showing a method for selectively forming a conductor according to the present embodiment. FIG. 4 is a cross-sectional view showing a method for selectively forming a conductor according to the present embodiment. FIG. 5 is a diagram schematically showing a method for selectively forming a conductor according to the present embodiment. FIG. 6 is a table showing the processing conditions of the method for selectively forming a conductor according to the present embodiment. FIG. 7 is a perspective view showing the vicinity of the conductor formed under the processing conditions shown in FIG. 6 using an SEM photograph. FIG. 8 is a cross-sectional view showing the vicinity of the conductor formed under the processing conditions shown in FIG. 6 using an SEM photograph.

  In the present embodiment, by utilizing the dissolving power equivalent to the liquid that the supercritical fluid has, the high diffusibility equivalent to the gas, the surface tension close to zero, and the high density, the concave portion with a fine and high aspect ratio is formed. A technique for selectively providing a conductor inside will be described. In this technique, a supercritical fluid is used as a solvent, and a metal compound that is a raw material for the conductor is dissolved as a solute in the supercritical fluid. Also, in this technology, the metal compound that is the raw material of the conductor is selected in a self-aligned manner inside the recess by utilizing the structure or physical shape of the base, not the base material on which the conductor is provided. Introduced. Hereinafter, it demonstrates concretely and in detail.

  First, the conductor selective forming apparatus 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, first and second cylinders 2 and 3 are provided in the most upstream portion of the conductor selective forming apparatus 1. Although not shown, carbon dioxide (CO ₂ ), which is a raw material for the supercritical fluid, is contained in the first cylinder 2 in a liquid state. Carbon dioxide becomes a supercritical fluid that is neither a liquid nor a gas and has both liquid phase (liquid) and gas phase (gas) properties in an atmosphere of about 31 ° C. and about 7.4 MPa. Specifically, carbon dioxide has a solubility equivalent to a liquid, a high diffusibility equivalent to a gas, a surface tension close to zero, and a high density in an atmosphere of about 31 ° C. and about 7.4 MPa. It becomes a state. The internal pressure of the first cylinder 2 is set to about 5 to 6 MPa. The first cylinder 2 is connected to a liquid feed pump 4. The pressure of the carbon dioxide delivered from the first cylinder 2 is increased to about 8 MPa by the liquid delivery pump 4. The pressure of the carbon dioxide that has passed through the liquid feed pump 4 is measured by the first pressure gauge 6.

Inside the second cylinder 3, hydrogen (H ₂ ) is accommodated as a substance that promotes the precipitation of the metal 10 from the metal compound 18 including the metal 20 that is a main component of the conductor 21 described later. Hydrogen has an action (entrainer effect) that increases the saturation solubility of the metal compound 18 in the supercritical fluid. The metal contained in the metal compound 18 that is excessively dissolved in the supercritical fluid is easily precipitated by the amount that is excessively dissolved. The second cylinder 3 is connected to a pressure regulator 7. The pressure of the hydrogen delivered from the second cylinder 3 is reduced to about 0.3 MPa by the pressure regulator 7. The hydrogen that has passed through the pressure regulator 7 passes through the check valve 5 and the first valve 8, and then merges with carbon dioxide that has passed through the first pressure gauge 6 at the junction J.

  The flow of carbon dioxide and hydrogen that has passed through the junction J is branched in two directions at a branch point D. One is supplied through the second valve 9 and the third valve 10 to the inside of the pressure-resistant reaction vessel 11 in which the object to be processed 16 provided with the conductor 21 and the metal compound 18 are arranged. On the other hand, the other is discharged to the outside of the conductor selective forming apparatus 1 through the back pressure valve 12. The back pressure valve 12 functions in the same manner as the pressure regulator 7 and adjusts the pressure of the entire line of the conductor selection and formation apparatus 1 so as to be maintained at an appropriate value. Note that the pressure of the entire line of the conductor selection and formation apparatus 1 is measured by a second pressure gauge 13 provided at an intermediate portion between the branch point D and the back pressure valve 12.

  For example, the pressure of the entire line of the conductor selective forming apparatus 1 is monitored by the second pressure gauge 13 such that the pressure of the entire line is in a range of about ± 10% and periodically rises and falls at a predetermined interval. The back pressure valve 12 is opened and closed at a predetermined cycle. Then, the pressure of the atmosphere inside the pressure resistant reactor 11 also rises and falls periodically within a range of about ± 10% and at a predetermined interval. As a result, the density of the atmosphere in the pressure resistant reactor 11 is in a range of about ± 10% and periodically becomes non-uniform at predetermined intervals. That is, a pulse-like fluctuation can be generated in the density of the atmosphere in the pressure resistant reactor 11. As a result, pulse-like fluctuations can be generated in the density of carbon dioxide, which is the raw material of the supercritical fluid supplied into the pressure resistant reactor 11. When the density of the supercritical fluid fluctuates, the solubility of the metal compound as a solute that dissolves in the supercritical fluid as a solvent increases.

  A mantle heater 14 for heating the inside of the pressure-resistant reaction vessel 11 is provided around the pressure-resistant reaction vessel 11. The mantle heater 14 has a three-layer structure of an upper mantle heater 14a, a middle mantle heater 14b, and a lower mantle heater 14c in order from the top along the height direction of the pressure resistant reactor 11. At the same time, the mantle heater 14 is arranged such that the center portion in the height direction coincides with the center portion in the height direction of the pressure resistant reactor 11 indicated by a one-dot chain line A-A ′ in FIG. 1. Further, the upper, middle, and lower mantle heaters 14a, 14b, and 14c operate independently of each other and can individually heat the inside of the pressure resistant reactor 11 from the upper part, the central part, and the lower part thereof.

  For example, when only the upper mantle heater 14a among the upper, lower, and lower mantle heaters 14a, 14b, and 14c is periodically operated at a predetermined interval, the inside of the pressure-resistant reaction vessel 11 is periodically changed from the upper side at a predetermined interval. Heated to the bias. Then, the inside of the pressure-resistant reaction vessel 11 is periodically heated to a higher temperature at a predetermined interval than the lower portion, and temperature unevenness occurs inside the pressure-resistant reaction vessel 11. When the internal temperature of the pressure-resistant reaction container 11 becomes uneven, convection is periodically generated in the atmosphere in the pressure-resistant reaction container 11 at a predetermined interval. Thereby, a difference in density is periodically generated at a predetermined interval between the upper part and the lower part of the atmosphere in the pressure resistant reactor 11. That is, a pulse-like density fluctuation occurs in the atmosphere in the pressure resistant reactor 11. As a result, as in the case where the back pressure valve 12 is opened and closed intermittently, pulse-like fluctuations can be generated in the density of carbon dioxide, which is the raw material of the supercritical fluid supplied into the pressure resistant reactor 11.

  Such a phenomenon can be caused not only by the upper mantle heater 14a but also by operating the middle mantle heater 14b and the lower mantle heater 14c individually and intermittently. Alternatively, the same phenomenon can be caused by intermittently operating any two of the upper, middle, and lower mantle heaters 14a, 14b, and 14c in combination. That is, the atmosphere in the pressure-resistant reaction vessel 11 can be obtained by intermittently operating the upper, middle, and lower mantle heaters 14a, 14b, and 14c in the same manner as the back pressure valve 12 is opened and closed intermittently. Can be made partially non-uniform periodically at a predetermined interval to cause a pulse-like density fluctuation in the atmosphere in the pressure resistant reactor 11. On the other hand, when the upper, middle, and lower mantle heaters 14a, 14b, and 14c are operated at the same time, the atmosphere in the pressure-resistant reaction vessel 11 is uniformly heated without causing uneven heating. That is, the atmosphere in the pressure resistant reactor 11 hardly causes a pulse-like density fluctuation in its density.

  As shown in FIG. 2, an object 16 to be processed in which a plurality of fine and high aspect ratio concave portions 15 provided with a conductor 21 are formed is accommodated inside the pressure resistant reactor 11. The object to be processed 16 is placed on a pedestal 17 serving as an object to be processed support provided inside the pressure-resistant reaction vessel 11 with each recess 15 facing upward. Further, inside the pressure-resistant reaction vessel 11, a metal compound 18 containing the metal 20 that is the main component of the conductor 21 is also accommodated. Although illustration is omitted, the pressure resistant reactor 11 is provided with a window for observing the inside.

  Next, a method for selectively forming a conductor according to the present embodiment will be described with reference to FIGS. Specifically, the method of selectively forming a conductor according to the present embodiment is a plurality of fine and high aspect ratio recesses formed in the surface layer portion of the object to be processed 16 by using the conductor selective forming apparatus 1 described above. 15 is a method in which the conductor 21 is selectively provided in the inside.

First, as shown in FIG. 2, the silicon substrate 16 and the metal compound 18 are disposed inside the pressure resistant reactor 11. In the present embodiment, a silicon substrate 16 made of silicon (Si) is used as an object to be processed. In this embodiment, ruthenium (Ru), which is a kind of metal belonging to the platinum group, is provided in each recess 15. Therefore, a material containing ruthenium is used for the metal compound 18. Here, a solid phase (solid) cyclopentadienyl ruthenium (Ru (C ₅ H ₅ ) ₂ , RuCp ₂ ), which is a kind of organometallic complex (precursor), is used as the metal compound 18 together with the silicon substrate 16 in a pressure resistant reaction. Arranged inside the container 11. The melting point of this cyclopentadienyl ruthenium is about 200 ° C.

  Next, as shown in FIG. 3 (a), the liquid feeding pump 4, the check valve 5, the pressure regulator 7, the first valve 8, the second valve 9, and the second 3 and the back pressure valve 12 are operated to supply appropriate amounts of hydrogen and liquid carbon dioxide to the inside of the pressure resistant reactor 11 in which the silicon substrate 16 and the solid cyclopentadienyl ruthenium 18 are accommodated, respectively. . In this state, cyclopentadienyl ruthenium 18 exists as a solid.

  Next, as shown in FIG.3 (b), the mantle heater 14 is operated and the pressure | voltage resistant reaction container 11 is heated from the outer side. At the same time, the inside of the pressure-resistant reaction vessel 11 is pressurized by operating a pump (not shown). As a result, the temperature of the atmosphere in the pressure-resistant reaction container 11 reaches about 31 ° C., and the pressure (total pressure) of the atmosphere in the pressure-resistant reaction container 11 reaches about 7.4 MPa. Then, at this stage, the carbon dioxide in the pressure resistant reactor 11 undergoes phase displacement from the liquid to the supercritical fluid. As described above, carbon dioxide that has become a supercritical fluid has a solubility equivalent to that of a liquid, a high diffusibility equivalent to that of a gas, a surface tension close to substantially zero, and a high density.

  Subsequently, the temperature and pressure of the atmosphere in the pressure-resistant reaction container 11 are further increased so that the temperature of the atmosphere in the pressure-resistant reaction container 11 reaches about 200 ° C., and the pressure (total pressure) of the atmosphere in the pressure-resistant reaction container 11 is reached. Of about 8 MPa. Then, at this stage, the cyclopentadienyl ruthenium 18 which is a solid organometallic complex melts and phase shifts from a solid phase (solid) to a liquid phase (liquid). Then, at least part of the cyclopentadienyl ruthenium 18a that has become liquid is molecular and dissolved and mixed in carbon dioxide, which is a supercritical fluid having the same dissolving ability as the liquid. That is, carbon dioxide that has become a supercritical fluid behaves as a solvent, and molecular cyclopentadienyl ruthenium 18b behaves as a solute. In the present embodiment, the cyclopentadienyl ruthenium 18a is dissolved until it becomes supersaturated with respect to carbon dioxide that has become a supercritical fluid so that ruthenium is easily precipitated from the liquid cyclopentadienyl ruthenium 18a.

  In order to dissolve the molecular cyclopentadienyl ruthenium 18b in the supercritical fluid carbon dioxide until it becomes supersaturated, as described above, in the atmosphere containing carbon dioxide that has become the supercritical fluid. Hydrogen may be added. According to this method, without introducing excessive solid cyclopentadienyl ruthenium 18 into the pressure-resistant reaction vessel 11, the cyclopentadienyl ruthenium 18a into the carbon dioxide that has become a supercritical fluid by the hydrogen entrainer effect. Solubility can be increased.

  Carbon dioxide that has become a supercritical fluid is an extremely stable object in terms of chemical reaction. Therefore, in a state where the molecular cyclopentadienyl ruthenium 18b is supersaturated with respect to the carbon dioxide of the supercritical fluid, the molecular cyclopentadienyl ruthenium 18b and carbon dioxide are separated from each other by their respective phases. It coexists in the atmosphere in the pressure resistant reactor 11 in a phase-separated state. That is, there is almost no possibility that the molecular cyclopentadienyl ruthenium 18b and the supercritical fluid carbon dioxide cause a chemical reaction with each other to cause alteration. In addition, since carbon dioxide in the supercritical fluid has a high diffusibility equivalent to that of gas, the molecular cyclopentadienyl ruthenium 18b is dissolved almost uniformly in the supercritical fluid carbon dioxide. Yes.

  As shown in FIG. 4A, when the silicon substrate 16 as a foreign object exists in an atmosphere in which molecular cyclopentadienyl ruthenium 18b, carbon dioxide as a supercritical fluid, or hydrogen 19 coexists, due to affinity. Molecular cyclopentadienyl ruthenium 18 b is attracted toward the silicon substrate 16. The molecular cyclopentadienyl ruthenium 18b comes into contact with the surface of the silicon substrate 16 and is adsorbed or adhered. However, the molecular cyclopentadienyl ruthenium 18b is in a high density state in which its fluidity is very rich because it is dissolved in carbon dioxide, a supercritical fluid whose surface tension is nearly zero. . For this reason, the molecular cyclopentadienyl ruthenium 18b adsorbed or adhered to the surface of the silicon substrate 16 smoothly flows along the surface of the silicon substrate 16 as shown in FIG. Are introduced in a self-aligning manner and selectively into each of the recesses 15 having a structure lower than the surface of the surface. That is, the molecular cyclopentadienyl ruthenium 18 b adsorbed or attached to the surface of the silicon substrate 16 is preferentially introduced into each recess 15.

  As shown in FIG. 4B, when the molecular cyclopentadienyl ruthenium 18 b enters the recesses 15, fluctuations occur in the density of the atmosphere in the pressure resistant reactor 11 near the surface of the silicon substrate 16. Eventually, fluctuations occur in the density of carbon dioxide in the supercritical fluid. Specifically, the density in the atmosphere in the pressure-resistant reaction container 11 and the carbon dioxide of the supercritical fluid is high in the upper part in the pressure-resistant reaction container 11 and is low in the lower part. Then, the plurality of molecular cyclopentadienyl rutheniums 18b dissolved in the supercritical fluid carbon dioxide in a supersaturated state are attracted to each other and aggregate by capillary action. As a result, liquid cyclopentadienyl ruthenium 18 a is deposited in each recess 15.

  As shown in FIG. 4 (c), the liquid cyclopentadienyl ruthenium 18a deposited in each recess 15 is sequentially turned from the bottom to the top of each recess 15 like a general liquid. Satisfy. As described above, since the carbon dioxide of the supercritical fluid has high density, the molecular cyclopentadienyl ruthenium 18b dissolved in the carbon dioxide of the supercritical fluid is placed inside each recess 15. It can enter with almost no gap. Therefore, the inside of each recess 15 is filled with liquid cyclopentadienyl ruthenium 18a sequentially from the bottom to the top without any gap.

  The liquid cyclopentadienyl ruthenium 18 a deposited in each recess 15 reacts with the hydrogen 19 and is reduced. As a result, ruthenium 20 which is the main component of the conductor 21 is decomposed from the liquid cyclopentadienyl ruthenium 18 a and deposited in each recess 15. Therefore, in the present embodiment, the inside of each recess 15 is filled with the liquid cyclopentadienyl ruthenium 18a without any gap sequentially from the bottom to the top thereof, and inside each recess 15 Ruthenium 20 precipitates sequentially from the bottom to the top without any gaps. The precipitation reaction of ruthenium 20 from the cyclopentadienyl ruthenium 18a is represented by the following chemical formula (1).

Ru ^II Cp ₂ + H ₂ → Ru ⁰ + 2HCp (1)
In the ruthenium precipitation reaction represented by the chemical formula (1), hydrogen 19 functions as a reducing agent for cyclopentadienyl ruthenium 18a. The ruthenium 20 deposited in each recess 15 is sequentially deposited from the bottom to the top in each recess 15 by capillary aggregation. Ruthenium 20 is deposited in each recess 15 until the inside of each recess 15 is filled with ruthenium 20 with almost no gap. Further, when hydrogen (H ₂ ) 19 is consumed in accordance with the chemical reaction represented by the chemical formula (1), the solubility of cyclopentadienyl ruthenium 18b in carbon dioxide in a supercritical fluid state decreases. Aggregation of ruthenium 20 proceeds more and more.

  Then, as shown in FIG. 4 (d), after ruthenium 20 is deposited from the inside of each recess 15 until the ruthenium 20 overflows on the surface of the silicon substrate 16, the liquid is supplied to the conductor selective forming apparatus 1. The pump 4, the check valve 5, the pressure regulator 7, the first valve 8, the second valve 9, the third valve 10, and the mantle heater 14 are stopped. Thereby, heating and pressurization of the atmosphere in the pressure-resistant reaction container 11 are stopped, and the temperature and pressure of the atmosphere in the pressure-resistant reaction container 11 are lowered. At the same time, the supply of carbon dioxide and hydrogen 19 into the pressure resistant reactor 11 is stopped. Subsequently, carbon dioxide, hydrogen 19 and the like are exhausted from the pressure resistant reactor 11.

  As a result, as shown in FIG. 5, a thin film 21 made of a single ruthenium as a conductor is formed inside and near the openings of a plurality of fine and high aspect ratio concave portions 15 formed in the surface layer portion of the silicon substrate 16. Are selectively provided. The inside of each recess 15 is filled with a ruthenium thin film (Ru thin film) 21 without a gap without forming a depletion (void).

  Next, experiments conducted by the inventors using the method for selectively forming a conductor according to the present embodiment described above will be described with reference to FIGS.

  As shown in FIG. 6, the present inventors tried the above-described method for selectively forming a conductor under a setting in which some of the processing conditions were changed. Specifically, the amount of cyclopentadienyl ruthenium 18 as a raw material for the ruthenium thin film 21 was set to either about 25 mg / cc or about 5 mg / cc. At the same time, the addition pressure of hydrogen 19 added to carbon dioxide, which is a supercritical fluid, was set to about 1 MPa or about 0.2 MPa. Note that the pressure (total pressure) of the atmosphere in the pressure resistant reactor 11 in which the silicon substrate 16 and the like are accommodated was set to about 12 MPa. The processing temperature for depositing the ruthenium thin film 21 was set to about 250 ° C. And the processing time at the time of performing the selective formation method of a conductor was set to about 15 minutes.

Although not shown in FIG. 6, the present inventors used first to fourth types of silicon substrates having different configurations as the silicon substrate 16. Specifically, the first silicon substrate has a configuration in which a silicon dioxide film (SiO ₂ film) as an insulating film is provided on a silicon layer as a substrate body. The second silicon substrate has a configuration in which the surface of the silicon dioxide film of the first silicon substrate is coated with a thin film of gold (Au) which is another conductor different from ruthenium. Further, the third silicon substrate has a structure in which the surface of the silicon dioxide film of the first silicon substrate is coated with a thin film of titanium nitride (titanium nitride, TiN) which is another conductor different from ruthenium. Become. Further, the fourth silicon substrate has a configuration in which the surface of the titanium nitride thin film of the third silicon substrate is further coated with a gold thin film.

  The inventors of the present invention formed a plurality of fine recess portions (grooves, holes) having a high aspect ratio in the surface layer portion of each of the first to fourth silicon substrates, and provided a conductor made of ruthenium inside each of the recess portions. Attempted to form. Each of the first to fourth silicon substrates is disposed in a sealed state in a pressure resistant reaction vessel 11 together with cyclopentadienyl ruthenium 18 and hydrogen 19 in carbon dioxide, which is a supercritical fluid. Such a processing method is called a batch method. Here, among the experiments using the batch method, the results of the experiment in which the thin film 21 made of ruthenium is formed in each of the recesses 15 formed in the second silicon substrate 16b, with reference to FIGS. explain. FIG. 7 and FIG. 8 show SEM results for the batch method described above with the amount of cyclopentadienyl ruthenium 18 set to about 25 mg / cc and the addition pressure of hydrogen 19 set to about 1.0 MPa. Shown using photographs.

  As shown in FIG. 7, it was confirmed that the ruthenium thin film 21 was selectively formed along the concave portions 15 on the gold thin film 24 constituting the surface of the second silicon substrate 16 b. As shown in FIG. 8, each recess 15 is formed in a silicon dioxide film 23 as an insulating film provided on the silicon layer 22 which is the substrate body of the second silicon substrate 16b. Then, like the surface of the second silicon substrate 16 b, the inner surface of each recess 15 is entirely covered with the gold thin film 24. The dimensions of each recess 15 are such that the bottom width is about 130 nm, the opening width is about 200 nm, and the depth is about 2 μm. That is, the aspect ratio of each recess 15 is about 10-15. As a result of performing the above-described batch method on the second silicon substrate 16b having such a configuration, as shown in FIG. 8, the inside of each recess 15 is filled with almost no gap from the bottom to the top thereof. It was confirmed that

  As described above, in the first embodiment, the solubility equal to that of a liquid, the high diffusibility equivalent to that of a gas, the surface tension close to substantially zero, the high density, and the supercriticality that is chemically stable. Liquid cyclopentadienyl ruthenium 18a, which is a raw material for the ruthenium thin film 21, is dissolved in carbon dioxide that has become a fluid. Thereby, even if the plurality of recesses 15 are fine and the aspect ratio is as high as about 10 to 15, the cyclopentadienyl ruthenium 18a can fill the inside with almost no gap. In addition, the cyclopentadienyl ruthenium 18a is placed in each recess 15 having a structure lower than the surface of the silicon substrate 16, regardless of the material (chemical nature) of the inner surface of each recess 15 serving as the base of the ruthenium thin film 21. It flows in a self-aligning manner and selectively. That is, the metal as the main component of the conductor can preferentially fill the recesses 15 using the structure or physical shape of the base, regardless of the material of the base. A method for forming a conductor utilizing such a principle (a method for depositing a conductor thin film) is also referred to as a shape-sensitive deposition method.

  The inside of each recess 15 is filled with cyclopentadienyl ruthenium 18a sequentially from the bottom to the top (opening) with almost no gap. At the same time, the cyclopentadienyl ruthenium 18a preferentially filled in the recesses 15 with almost no gap is filled with the ruthenium 20 deposited from the cyclopentadienyl ruthenium 18a sequentially from the bottom to the top of each recess 15. To go. As a result, even if the recesses 15 are fine and have a high aspect ratio, they are efficiently and selectively embedded by the ruthenium thin film 21 without any gaps, regardless of the underlying material. As described above, the film formation method (deposition method) in which each recess 15 is sequentially filled or filled from the bottom to the top is also referred to as a bottom-up film formation method (bottom-up deposition method). it can.

  In addition, the method for selectively forming a conductor according to this embodiment, which combines a supercritical fluid and a shape-sensitive deposition method, is less likely to be contaminated with impurities than the CVD method. In addition, the method for selectively forming a conductor according to the present embodiment is a much higher density process than the PVD method or the CVD method. Therefore, the concave portion 15 having a high aspect ratio and a complicated shape can be embedded efficiently and easily. Complicated shape parts can be created at higher speed. That is, the method for selectively forming a conductor according to the present embodiment has a higher throughput than the PVD method or the CVD method. For example, in the PVD method or the CVD method, a conductor film is formed not only on the recess but also on the entire surface of the layer where the recess is formed. On the other hand, the method for selectively forming a conductor according to the present embodiment can selectively form a conductor film only inside or in the vicinity of the recess 15, so that it is a raw material compared with the PVD method or the CVD method. Is not wasted, and the entire CMP process and the like can be omitted. That is, the method for selectively forming a conductor according to the present embodiment has higher production efficiency than the PVD method or the CVD method.

  In addition, in the metal organic chemical vapor deposition method using a liquid material, the liquid material is chemically unstable and the process margin is small, whereas in the selective formation method of the conductor of this embodiment, the material is chemically stable. Large process margin. At the same time, the method for selectively forming a conductor according to the present embodiment has a wide process margin of deposition temperature because the ruthenium thin film 21 can be formed at a lower temperature than the PVD method or the CVD method. That is, the method for selectively forming a conductor according to the present embodiment can relax the process temperature dependency. Furthermore, the method for selectively forming a conductor according to the present embodiment has a high recovery rate of expensive and rare raw materials as compared with the PVD method and the CVD method, and is easy to reuse. As described above, the method for selectively forming a conductor according to the present embodiment is more energy efficient than the PVD method and the CVD method, and thus has high process efficiency and is friendly to the environment. Furthermore, according to the method for selectively forming a conductor according to the present embodiment, the process can be omitted or the amount of raw material used can be suppressed or reduced as compared with the PVD method and the CVD method. Compared with the CVD method, the manufacturing cost can be easily suppressed or reduced.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described with reference to FIGS. FIG. 9 is a cross-sectional view or perspective view showing the vicinity of a conductor formed by the method for selectively forming a conductor according to the present embodiment using an SEM photograph. FIG. 10 is a cross-sectional view or plan view showing the vicinity of a conductor formed by the method for selectively forming a conductor according to the present embodiment using an SEM photograph. FIG. 11 is a cross-sectional view or perspective view showing the vicinity of a conductor formed by the method for selectively forming a conductor according to the present embodiment using an SEM photograph. FIG. 12 is a table showing the processing conditions for forming the conductor shown in FIGS. 9 to 10. FIG. 13 is a table showing the results obtained by the method for selectively forming conductors according to the present embodiment, classified according to the processing conditions shown in FIG. In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment mentioned above, and those detailed description is abbreviate | omitted.

  In the present embodiment, a description will be given of the results of experiments performed by the present inventors in the first embodiment described above with slightly different processing conditions.

As shown in FIG. 12, in this embodiment, unlike the experiment described in the first embodiment, the amount of cyclopentadienyl ruthenium (Ru (Cp) ₂ ) 18 that is a raw material of the ruthenium thin film 21 is about 50 mg. / Cc or about 10 mg / cc. Other processing conditions are the same as in the experiment described in the first embodiment. Under such processing conditions, an attempt was made to form the ruthenium thin film 21 on each of the first to fourth silicon substrates described above using the method for selectively forming a conductor described in the first embodiment. And the experimental result was analyzed about two points, the deposition condition (embedding property) and shape sensitivity (selectivity) of the ruthenium thin film 21, with respect to each of the first to fourth silicon substrates.

As shown in FIGS. 9A to 9D, the first silicon substrate 16a has a structure in which a silicon dioxide film (SiO ₂ film) 23 as an insulating film is provided on a silicon layer 22 as a substrate body. Consists of. The second silicon substrate 16b has a configuration in which the surface of the silicon dioxide film 23 of the first silicon substrate 16a is coated with a thin film 24 of gold (Au). The third silicon substrate 16c has a configuration in which the surface of the silicon dioxide film 23 of the first silicon substrate 16a is coated with a thin film 31 of titanium nitride (TiN). Further, the fourth silicon substrate 16 d has a configuration in which the surface of the titanium nitride thin film 31 of the third silicon substrate 16 c is further coated with the gold thin film 24.

  First, in FIG. 9A, the amount of cyclopentadienyl ruthenium 18 is set to about 50 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the first silicon substrate 16a is applied. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 9A, the ruthenium thin film 21 is deposited with the recesses 15 being embedded with almost no gaps, and the ruthenium thin film 21 is deposited well. However, the ruthenium thin film 21 is deposited over the entire surface of the first silicon substrate 16a as well as in the vicinity of each recess 15 and its opening. Therefore, the shape sensitivity of the ruthenium thin film 21 cannot be expected so much.

  Next, in FIG. 9B, the amount of cyclopentadienyl ruthenium 18 is set to about 50 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the second silicon substrate 16b is applied. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 9B, the ruthenium thin film 21 is deposited so as to embed each recess 15, and the deposition state of the ruthenium thin film 21 is good. Further, the ruthenium thin film 21 is selectively deposited along each recess 15 and in the vicinity of the opening. Therefore, the shape sensitivity of the ruthenium thin film 21 is also good.

  Next, in FIG. 9C, the amount of cyclopentadienyl ruthenium 18 is set to about 50 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the third silicon substrate 16c is applied to the third silicon substrate 16c. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 9C, the ruthenium thin film 21 is deposited with the recesses 15 being embedded with almost no gaps, and the deposition state of the ruthenium thin film 21 is good. However, as in the case of the first silicon substrate 16a, the ruthenium thin film 21 is deposited on the entire surface of the third silicon substrate 16c in a thick shape as well as in the vicinity of each recess 15 and its opening. Yes. Therefore, the shape sensitivity of the ruthenium thin film 21 cannot be expected so much.

  Next, in FIG. 9 (d), the amount of cyclopentadienyl ruthenium 18 is set to about 50 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 9 (d), the ruthenium thin film 21 is deposited with the recesses 15 buried almost without any gaps, and the deposition state of the ruthenium thin film 21 is good. However, as in the case of the first and third silicon substrates 16a and 16c, the ruthenium thin film 21 is not only thicker on the surface of the fourth silicon substrate 16d but also on the surface of the fourth silicon substrate 16d. Accumulated in the form of meat. Therefore, the shape sensitivity of the ruthenium thin film 21 cannot be expected so much.

  Next, in FIG. 10A, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the first silicon substrate 16a is applied. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 10 (a), the ruthenium thin film 21 is deposited with the recesses 15 buried almost without any gaps, and the ruthenium thin film 21 is deposited well. Further, the ruthenium thin film 21 is selectively deposited along each recess 15 and in the vicinity of the opening. Therefore, the shape sensitivity of the ruthenium thin film 21 is also good.

  Next, in FIG. 10B, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the second silicon substrate 16b is applied. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 10B, the ruthenium thin film 21 embeds the concave portions 15 in an uneven manner, and the deposition state cannot be expected much. Further, the ruthenium thin film 21 is deposited not only in the vicinity of each recess 15 and its opening but also on the surface of the third silicon substrate 16c so as to rise in a mountain shape. Therefore, the shape sensitivity of the ruthenium thin film 21 is poor.

  Next, in FIG. 10C, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the third silicon substrate 16c is applied to the third silicon substrate 16c. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 10 (c), the ruthenium thin film 21 almost embeds each recess 15 and the deposition state is bad. Also, the ruthenium thin film 21 is hardly deposited anywhere on the surface of the third silicon substrate 16c as well as in the vicinity of each recess 15 and its opening. Therefore, the shape sensitivity of the ruthenium thin film 21 is also poor.

  Next, in FIG. 10D, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 1 MPa, and then the fourth silicon substrate 16d is applied to the fourth silicon substrate 16d. The result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 10 (d), the ruthenium thin film 21 is deposited with the recesses 15 partially embedded, with almost no gaps, and the ruthenium thin film 21 is deposited well. Further, the ruthenium thin film 21 is selectively deposited along each recess 15 and in the vicinity of the opening. Therefore, the shape sensitivity of the ruthenium thin film 21 is also good.

  Next, FIG. 11A shows the first silicon substrate 16a after the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 0.2 MPa. On the other hand, the result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 11A, the ruthenium thin film 21 hardly embeds the recesses 15, and the deposition state of the ruthenium thin film 21 is bad. As a result, the shape sensitivity of the ruthenium thin film 21 cannot be determined.

  Next, in FIG. 11B, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 0.2 MPa, and then the second silicon substrate 16b. On the other hand, the result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is clear from the photograph shown in FIG. 11B, the ruthenium thin film 21 is partially embedded in each concave portion 15 and is deposited, and the deposition state of the ruthenium thin film 21 is good. However, the ruthenium thin film 21 is deposited not only in the vicinity of each recess 15 and its opening but also on the entire surface of the fourth silicon substrate 16d in a thick shape. Therefore, the shape sensitivity of the ruthenium thin film 21 is poor.

  Next, in FIG. 11C, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 0.2 MPa, and then the third silicon substrate 16c. On the other hand, the result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is clear from the photograph shown in FIG. 11C, the ruthenium thin film 21 is hardly deposited anywhere on the surface of the third silicon substrate 16c as well as in the vicinity of each recess 15 and its opening. Therefore, the deposition situation of the ruthenium thin film 21 is bad. As a result, the shape sensitivity of the ruthenium thin film 21 cannot be determined.

  Next, in FIG. 11D, the amount of cyclopentadienyl ruthenium 18 is set to about 10 mg / cc and the addition pressure of hydrogen 19 is set to about 0.2 MPa, and then the fourth silicon substrate 16d. On the other hand, the result of having conducted the experiment which forms the ruthenium thin film 21 with the selective formation method of the conductor demonstrated in 1st Embodiment is shown. As is apparent from the photograph shown in FIG. 11 (d), the ruthenium thin film 21 is deposited with the recesses 15 buried almost without any gaps, and the deposition state of the ruthenium thin film 21 is good. However, the ruthenium thin film 21 is deposited not only in the vicinity of each recess 15 and its opening but also on the entire surface of the fourth silicon substrate 16d in a thick shape. As a result, the shape sensitivity of the ruthenium thin film 21 cannot be determined.

The results of the experiment of the present embodiment described above with reference to FIGS. 9A to 9D, FIGS. 10A to 10D, and FIGS. 11A to 11D are shown in FIG. It shows together as a table. In FIG. 13, “◯” indicates good. Further, in FIG. 13, the Δ mark indicates that it is neither possible nor impossible. And the x mark in FIG. 13 represents a defect. From the results shown in FIG. 13, it was found that the shape sensitivity of the ruthenium thin film 21 improved as the amount of cyclopentadienyl ruthenium (Ru (Cp) ₂ ) 18 increased. It was also found that if the amount of hydrogen 19 added is too large, the film formation reaction of the ruthenium thin film 21 may become unstable.

Further, from the results shown in FIG. 13 and the photographs shown in FIGS. 9 (a) to (d), FIGS. 10 (a) to (d), and FIGS. 11 (a) to (d), It was found that the material of the ruthenium thin film 21 has little relation to the shape sensitive deposition. It was found that the base material of the ruthenium thin film 21 affects the amount of the ruthenium thin film 21 deposited. Specifically, when the base material of the ruthenium thin film 21 is made of a conductor such as an Au thin film 24 or a TiN thin film 31, the base material of the ruthenium thin film 21 is made of an insulating film such as a SiO ₂ film 23. It was found that the deposition amount of the ruthenium thin film 21 increased. Therefore, in order to increase the deposition amount of the ruthenium thin film 21, the base of the ruthenium thin film 21 may be formed of a conductor.

  As described above, according to the second embodiment, the same effects as those of the first embodiment described above can be obtained.

(Third embodiment)
Next, a third embodiment according to the present invention will be described with reference to FIG. FIG. 14 is a cross-sectional view showing the vicinity of a conductor formed by the method for selectively forming a conductor according to the present embodiment using an SEM photograph. In addition, the same code | symbol is attached | subjected to the same part as each 1st and 2nd embodiment mentioned above, and those detailed description is abbreviate | omitted.

  In the present embodiment, a thin film made of copper (Cu) is provided as the conductor provided in the recess 15 of the silicon substrate 16.

Specifically, the silicon substrate used in the present embodiment is the fourth silicon substrate 16d described in the second embodiment. That is, the silicon substrate 16d used in this embodiment is provided with a silicon dioxide film (SiO ₂ film) 23 as an insulating film on a silicon layer (Si layer) 22 as a substrate body, as shown in FIG. Based on composition. A plurality of fine recesses 15 having a high aspect ratio are formed inside the silicon dioxide film 23. Each recess 15 has a width of about 100 nm and a depth of about 500 nm. That is, the aspect ratio of each recess 15 in this embodiment is about 5.

  A thin film 31 of titanium nitride (TiN) is entirely coated on the surface of the silicon dioxide film 23 including the inner surface of each recess 15. Further, a gold (Au) thin film 24 is entirely coated on the surface of the TiN thin film 31. The Au thin film 24 is formed on the surface of the TiN thin film 31 by vapor deposition. As a result, the TiN thin film 31 is suppressed and the surface conductivity of the underlying layer on which the copper (Cu) thin film 41 is provided is recovered or improved.

As a metal compound containing Cu that is a raw material of the Cu thin film 41, for example, diisobutyryl methanate copper (Cu (C ₇ H ₁₅ O ₂ ) ₂ , Cu (divm) ₂ ), which is a kind of organometallic complex, is used. Moreover, the pressure (total pressure) of the atmosphere in the pressure resistant reactor 11 is set to about 13 MPa. Moreover, the temperature of the atmosphere in the pressure | voltage resistant reaction container 11 is set to about 230 degreeC. The addition pressure of hydrogen 19 is set to about 0.3 MPa. Furthermore, the processing time for forming (depositing) the Cu thin film 41 was set to about 15 minutes. Under such conditions, the method for selectively forming a conductor described in the first embodiment is executed.

  As a result, as shown in FIG. 14, the Cu thin film 41 could be selectively deposited inside and above some of the recesses 15.

  As described above, according to the third embodiment, even when copper is used instead of ruthenium, the same effects as those of the first and second embodiments described above can be obtained. That is, even when the Cu thin film 41 is used, the inside of each recess 15 can be embedded by a bottom-up film forming method (bottom-up deposition method), as in the case of using the Ru thin film 21 of the first embodiment.

(Fourth embodiment)
Next, a fourth embodiment according to the present invention will be described with reference to FIG. FIG. 15 is a cross-sectional view illustrating the method for manufacturing the semiconductor device according to the present embodiment. In addition, the same code | symbol is attached | subjected to the same part as each 1st-3rd embodiment mentioned above, and those detailed description is abbreviate | omitted.

  In the present embodiment, a technique for manufacturing a semiconductor device using the conductor selective formation method described in the first embodiment will be described. Specifically, the buried electrode of the trench capacitor is formed using the above-described method for selectively forming a conductor.

As shown in FIG. 15, the silicon substrate 16 used in this embodiment has a P-type silicon layer (Si layer) 22 as its substrate body. The surface layer portion of the P-type silicon layer 22 is a P well 51. A fine recess portion (trench) 52 having a high aspect ratio is formed inside the P well 51 which is also a surface layer portion of the silicon substrate 16. An n-type impurity is introduced into the surface layer portion inside the trench 52 by ion implantation or the like, and becomes the cathode 53 of the trench capacitor 58. In addition, a silicon oxide film (SiO ₂ film) 54 serving as a capacitive insulating film is provided inside the trench 52 so as to cover the surface of the cathode 53. Further, in the surface layer portion of the silicon substrate 16, an element isolation region 55 and an n ⁺ -type impurity diffusion region 56 serving as a source region or a drain region of a transistor (not shown) are formed.

  After the silicon substrate 16 having such a structure is accommodated in the pressure-resistant reaction vessel 11, the method for selectively forming a conductor described in the first embodiment is executed. At this time, in the case where the conductor provided in the trench 52 is formed of Ru, among the processing conditions of the first and second embodiments described above, processing conditions having good deposition properties and shape sensitivity are adopted. Just do it. As a result, the Ru film 57 that becomes the buried electrode of the trench capacitor 58 can be formed selectively and in the vicinity of the opening of the trench 52 with a fine and high aspect ratio, and with almost no gap. After the film forming process of the Ru film 57 is completed, the silicon substrate 16 is taken out from the inside of the pressure resistant reactor 11 and the Ru film 57 is formed into a desired embedded electrode shape by an etching process or the like. As a result, a plate electrode 57 as a buried electrode formed in a desired shape using the Ru film is provided on the surface layer portion of the silicon substrate 16. As a result, a trench capacitor 58 including a cathode 53, a capacitive insulating film 54, and a plate electrode 57 is provided on the surface layer portion of the silicon substrate 16.

  Thereafter, the word 59, the bit line 60, the contact plug 61 for obtaining conduction between the bit line 60 and the impurity diffusion region 56, and the interlayer are formed on the surface of the silicon substrate 16 provided with the trench capacitor 58 by a known technique. An insulating film 62 or the like may be provided. Of course, like the plate electrode 57, the contact plug 61 may be formed by the method for selectively forming a conductor described in the first embodiment. The semiconductor device 63 having the structure shown in FIG.

  As described above, according to the fourth embodiment, the same effects as those of the first to third embodiments described above can be obtained. Further, the trench capacitor 58 including the plate electrode 57 having a three-dimensional and complicated shape can be formed efficiently and easily. As a result, the semiconductor device 63 including the trench capacitor 58 can be manufactured efficiently and easily. Such a semiconductor device 63 can be manufactured at low cost because the production efficiency is good and the manufacturing process can be simplified.

(Fifth embodiment)
Next, a fifth embodiment according to the present invention will be described with reference to FIG. FIG. 16 is a cross-sectional view showing the method for manufacturing a semiconductor device according to this embodiment. In addition, the same code | symbol is attached | subjected to the same part as each 1st-4th embodiment mentioned above, and those detailed description is abbreviate | omitted.

  In the present embodiment as well, as in the fourth embodiment described above, a technique for manufacturing a semiconductor device using the conductor selective formation method described in the first embodiment will be described. However, in the present embodiment, unlike the fourth embodiment, the multilayer wiring structure is formed using the above-described method for selectively forming a conductor.

  First, as shown in FIG. 16A, a case will be described in which a multilayer wiring structure including an upper layer wiring having a so-called single damascene structure in which wirings and plugs are formed separately is described.

  First, a first interlayer insulating film 23a is provided on the substrate body 22 of the silicon substrate 16 by a well-known CVD method. Subsequently, a lower-layer wiring forming recess 71 for providing the first-layer wiring 73 serving as the lower-layer wiring is formed in the first-layer interlayer insulating film 23a by a known etching process or the like. Subsequently, the lower layer wiring barrier metal film 72 and the lower layer wiring Cu film 73 are embedded in the lower layer wiring forming recess 71 by a known CVD method, CMP method or the like. As a result, a first layer wiring 73 serving as a lower layer wiring is provided in the first layer interlayer insulating film 23a.

  Subsequently, an interlayer insulating film 23b on the lower layer side of the second interlayer insulating film is provided on the first interlayer insulating film 23a provided with the lower Cu wiring 73 by a well-known CVD method. Subsequently, a via hole 74 for providing a via plug 76 for obtaining conduction between the lower layer Cu wiring 73 and the upper layer wiring 79 is formed in the second layer lower interlayer insulating film 23b by a known etching process or the like. . Subsequently, a via plug barrier metal film 75 is formed on the surface of the second lower interlayer insulating film 23 b including the inner surface of the via hole 74 by a known CVD method or the like.

  Subsequently, the silicon substrate 16 provided with the barrier metal film 75 is accommodated in the pressure resistant reactor 11. Thereafter, the method for selectively forming a conductor described in the first embodiment is executed. At this time, when the via plug 76 is formed of Cu, the processing conditions of the third embodiment described above may be employed. As a result, a Cu film 76 serving as a via plug can be formed selectively inside and around the opening of the fine and high aspect ratio via hole 74 and with almost no gap. After the formation of the Cu film 76 is completed, the silicon substrate 16 is taken out from the inside of the pressure resistant reactor 11, and the Cu film 76 and the barrier metal film 75 are embedded in the via hole 74 by a known CMP process or the like. As a result, the Cu via plug 76 is provided in the second-layer lower interlayer insulating film 23b.

  Subsequently, an interlayer insulating film 23c on the upper layer side of the second interlayer insulating film is provided on the second lower interlayer insulating film 23b provided with the Cu via plug 76 by a known CVD method. . Subsequently, an upper-layer wiring forming recess 77 for providing the upper-layer wiring 79 is formed in the second-layer upper interlayer insulating film 23c by a known etching process or the like. Subsequently, an upper-layer wiring barrier metal film 78 is formed on the surface of the second-layer upper-layer interlayer insulating film 23c including the inner surface of the upper-layer wiring forming recess 77 by a known CVD method or the like.

  Subsequently, the silicon substrate 16 provided with the barrier metal film 78 is accommodated again in the pressure resistant reactor 11. Thereafter, the method for selectively forming a conductor described in the first embodiment is executed. At this time, when the upper layer wiring 79 is formed of Cu, the processing conditions of the third embodiment described above may be employed as in the case of forming the Cu via plug 76. As a result, the Cu film 79 serving as the upper layer wiring can be formed selectively and in the vicinity of the opening of the fine upper layer wiring forming recess 77 and with almost no gap. After the formation of the Cu film 79 is completed, the silicon substrate 16 is taken out of the pressure-resistant reaction vessel 11 again, and the Cu film 79 and the barrier metal film 78 are formed inside the upper wiring formation recess 77 by a known CMP process or the like. Embed in. Thus, the second-layer wiring 79 formed separately from the Cu via plug 76 is provided in the second-layer upper interlayer insulating film 23c. That is, an upper layer Cu wiring 79 having a so-called single damascene structure is provided in the second layer upper interlayer insulating film 23c.

  16A, the upper Cu wiring 79 and the lower Cu wiring 73 having a single damascene structure are made conductive through the barrier metal films 75 and 78 and the Cu via plug 76. A semiconductor device 80 having an upper and lower two-layer wiring structure is obtained.

  Next, as shown in FIG. 16B, a case will be described in which a multilayer wiring structure including an upper layer wiring having a so-called dual damascene structure in which wiring and a plug are integrally formed is described.

  First, the lower layer Cu wiring 73 is provided in the first-layer interlayer insulating film 23a by the same process as that for manufacturing the semiconductor device 80 described above.

  Subsequently, a second interlayer insulating film 23d is provided on the first interlayer insulating film 23a provided with the lower layer Cu wiring 73 by a well-known CVD method. Subsequently, the upper layer wiring forming recess 81 for providing the upper layer wiring and the via hole 82 for providing the via plug for obtaining the conduction between the upper layer wiring and the lower layer Cu wiring 73 are formed in the second layer by a known etching process or the like. In the interlayer insulating film 23d of the eye, they are integrally formed in communication with each other. Subsequently, an upper wiring barrier metal film 83 is formed on the surface of the second-layer interlayer insulating film 23d including the inner surface of the via hole 82 by a known CVD method or the like.

  Subsequently, the silicon substrate 16 provided with the barrier metal film 83 is accommodated in the pressure resistant reactor 11. Thereafter, the method for selectively forming a conductor described in the first embodiment is executed. At this time, when the upper layer wiring and the via plug are formed of Cu, the processing conditions of the third embodiment may be adopted as in the case of manufacturing the semiconductor device 80 described above. As a result, the via plug 82 and the upper layer can be selectively formed inside the via hole 82 and the upper-layer wiring forming recess 81 having a fine and high aspect ratio, and around the opening of the upper-layer wiring forming recess 81 with little or no gap. A Cu film to be a wiring can be formed. After the Cu film formation process is completed, the silicon substrate 16 is taken out of the pressure-resistant reaction container 11 and the Cu film and the barrier metal film 83 are formed in the via hole 82 and the upper wiring formation recess 81 by a known CMP process or the like. Embed inside. Thus, the second layer wiring 85 formed integrally with the Cu via plug 84 is provided in the second layer interlayer insulating film 23d. That is, the upper layer Cu wiring 85 having a so-called dual damascene structure is provided in the second interlayer insulating film 23d.

  16B, the upper Cu wiring 85 and the lower Cu wiring 73 having a dual damascene structure are made conductive through the barrier metal films 72 and 83 and the Cu via plug 84. A semiconductor device 86 having an upper and lower two-layer wiring structure is obtained.

  As described above, according to the fifth embodiment, the same effects as those of the first to fourth embodiments described above can be obtained. Further, like the upper layer Cu wirings 79 and 85 and the Cu via plugs 76 and 84, the lower layer Cu wiring 73 may of course be formed by the method for selectively forming a conductor described in the first embodiment.

  The method for selectively forming a conductor and the method for manufacturing a semiconductor device according to the present invention are not limited to the first to fifth embodiments described above. Without departing from the spirit of the present invention, a part of the configuration or manufacturing process can be changed to various settings, or various settings can be appropriately combined and used. .

  For example, in the method of excessively dissolving liquid cyclopentadienyl ruthenium 18a in carbon dioxide that has become a supercritical fluid, hydrogen 19 is mixed in the carbon dioxide that has become the supercritical fluid employed in the first embodiment. It is not limited only to the method. By increasing the amount of cyclopentadienyl ruthenium 18 charged relative to the volume in the pressure-resistant reaction vessel 11, the liquid cyclopentadienyl ruthenium 18a may be excessively dissolved in carbon dioxide that has become a supercritical fluid. In this case, excess cyclopentadienyl ruthenium 18 may be accommodated in advance in the pressure resistant reactor 11 prior to performing the selective formation process of the conductor according to the present invention.

  In each of the first, second, and fourth embodiments, the ruthenium thin film 21 that has been studied as a so-called glue film is formed as the conductor provided in each recess 15. In each of the third and fifth embodiments, Cu thin films 41, 76, 79, 84, and 85 are formed as conductors provided in the respective recesses 15. However, the conductor provided in each recess 15 is not necessarily limited to ruthenium or copper. The conductor provided in each recess 15 may be a conductor whose main component is a metal belonging to the platinum group other than ruthenium. Specifically, according to the process of selectively forming a conductor according to the present invention, the conductive material mainly composed of platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), or osmium (Os). The body can also be provided in the recess 15.

The organometallic complex (precursor) containing ruthenium 20 and 21 is not limited to the above-described cyclopentadienyl ruthenium (Ru (C ₅ H ₅ ) ₂ , RuCp ₂ ) 18. In addition to cyclopentadienylruthenium 18, examples of organometallic complexes containing ruthenium 20 and 21 include organic Ru such as RuCpMe, Ru (C ₅ HF ₆ O ₂ ) ₂ , Ru (C ₁₁ H ₁₉ O ₂ ) _3. Even if a compound, an oxygen-containing Ru complex, or the like is used, the same effects as those of the first, second, and fourth embodiments can be obtained. Similarly, the organometallic complex including Cu41 is not limited to diisobutyryl methanate copper described above _{(Cu (C 7 H 15 O} 2) 2, Cu (dibm) 2). In addition to diisobutyrylmethanate copper, for example, Cu ⁺² (hexafluoroacetylacetonate) ₂ , Cu ⁺² (acetylacetonate) ₂ , Cu ⁺² (2, 2, Even when 6,6-tetramethyl-3,5-heptanedione) ₂ or the like is used, the same effects as those of the third and fifth embodiments can be obtained. Moreover, the metal compound (organometallic complex) containing the metal which is the main component of these conductors does not necessarily need to be in a solid phase (solid state) before processing. The phase (state) before the treatment of the metal compound containing the metal as the main component of the conductor may be a liquid phase (liquid).

  Further, the conductor provided in each recess 15 is not necessarily limited to a single metal made of a single metal such as ruthenium or copper. For example, the conductor provided in each recess 15 may be an alloy made of two or more kinds of metals. The conductor provided in each recess 15 only needs to contain at least one metal and have conductivity. For example, in the method for selectively forming a conductor according to the present invention, an organometallic complex as a metal compound containing copper and an organometallic complex as a metal compound containing aluminum are dissolved in carbon dioxide as a supercritical fluid. In this way, an alloy of copper and aluminum can be provided in each recess 15.

The raw material for the supercritical fluid is not limited to carbon dioxide. Examples of other supercritical fluid materials include ethane (C ₂ H ₆ ), dinitrogen monoxide (N ₂ O), butane (C ₃ H ₈ ), ammonia (NH ₃ ), and hexane (C ₆ H ₁₄ ). , Methanol (CH ₃ OH), ethanol (C ₂ H ₅ OH), water (H ₂ O), and the like. Among these materials, ethane (C ₂ H ₆ ) has a critical temperature at which it becomes a supercritical fluid is about 32 ° C., and a critical pressure is about 4.9 MPa. In addition, dinitrogen monoxide (N ₂ O) has a critical temperature of about 36 ° C., which becomes a supercritical fluid, and a critical pressure of about 7.2 MPa. That is, ethane (C ₂ H ₆ ) and dinitrogen monoxide (N ₂ O) are materials that are as easy to handle as carbon dioxide.

  Further, the amount of cyclopentadienyl ruthenium 18a dissolved in carbon dioxide that has become a supercritical fluid may not be the supersaturated state described above. Depending on the desired deposition rate of ruthenium 20, the amount of cyclopentadienyl ruthenium 18a dissolved in carbon dioxide that has become a supercritical fluid may be set to subsaturation or saturation.

  Further, it is not always necessary to mix hydrogen 19 which is a substance that promotes precipitation of ruthenium 20 into carbon dioxide that has become a supercritical fluid. Instead of mixing hydrogen 19 into carbon dioxide that has become a supercritical fluid, as described in the first embodiment, at least one of the temperature and pressure of the atmosphere in the pressure resistant reactor 11 is changed to make it non-uniform. By doing so, the density of the supercritical fluid may be fluctuated. Also by such a method, the density of the supercritical fluid can be made non-uniform to cause density fluctuation, and the precipitation of ruthenium 20 from the cyclopentadienyl ruthenium 18a can be promoted. Or you may use together such a method and mixing of the hydrogen 19 in a supercritical fluid.

  Further, the method of causing fluctuations in the density of the supercritical fluid by changing the temperature of the atmosphere in the pressure resistant reactor 11 to make it non-uniform is the mantle heaters 14a in the upper, middle, and lower sides described in the first embodiment. , 14b, 14c are not limited to a method of operating them independently of each other. For example, the pressure-resistant reaction vessel 11 is substantially displaced by shifting the pressure-resistant reaction vessel 11 itself from the center position in the height direction in the initial setting of the pressure-resistant reaction vessel 11 and the mantle heater 14 indicated by a one-dot chain line AA ′ in FIG. May be set so as to be heated unevenly by the mantle heater 14. Also by such a method, the same effect as the case where the upper, middle, and lower mantle heaters 14a, 14b, and 14c are operated independently of each other can be obtained.

  Further, the timing of mixing the hydrogen 19 in the supercritical fluid does not necessarily have to be parallel to the process of dissolving the cyclopentadienyl ruthenium 18a in the carbon dioxide that has become the supercritical fluid. For example, the inside of each recess 15 may be once filled with cyclopentadienyl ruthenium 18a, and then hydrogen 19 may be mixed into the supercritical fluid.

  Further, the application example of the method for selectively forming a conductor according to the present invention is not limited to the method for manufacturing a semiconductor device described in the fifth embodiment. Other application examples of the method for selectively forming a conductor according to the present invention include, for example, a method for manufacturing a high-density magnetic recording medium (nanodot magnetic recording medium), a nonlinear optical element, or the like. Alternatively, in the method of selectively forming a conductor according to the present invention, in a step of forming a fine wiring inside a fine semiconductor element such as a CMOS, a seed film made of a conductor serving as a basis of the wiring is formed with a fine and high aspect ratio. Of course, the present invention can also be applied to a process of forming in a recess such as a hole or groove.

  Furthermore, although detailed and detailed explanations with illustrations are omitted, according to experiments conducted by the present inventors, by using the method for selectively forming a conductor according to the present invention, as in the third embodiment, It has been found that a conductor can be selectively provided not only in a recess having a width of about 100 nm but also in an extremely fine recess having a width of about 10 nm or less. That is, according to the method for selectively forming a conductor according to the present invention, it is virtually impossible to bury the inside without a gap by a conventional CVD method or PVD method, etc., inside an extremely fine and high aspect ratio recess. However, it has been found that the conductor can be embedded efficiently and easily without a gap. That is, it has been found that the method for selectively forming a conductor according to the present invention can be sufficiently applied to manufacturing processes of various elements and devices that require a conductor having a finer and more complicated structure and shape in the future.

The block diagram which simplifies and shows the selective formation apparatus of the conductor which concerns on 1st Embodiment. Sectional drawing which simplifies and shows the inside of the reaction container with which the selection formation apparatus of the conductor shown in FIG. 1 is provided. The figure which shows typically the selective formation method of the conductor which concerns on 1st Embodiment. Sectional drawing which shows the selective formation method of the conductor which concerns on 1st Embodiment. The figure which shows typically the selective formation method of the conductor which concerns on 1st Embodiment. The figure which shows the process conditions of the selective formation method of the conductor which concerns on 1st Embodiment as a table | surface. The perspective view which shows the vicinity of the conductor formed on the process conditions shown in FIG. 6 using a SEM photograph. Sectional drawing which shows the vicinity of the conductor formed on the process conditions shown in FIG. 6 using a SEM photograph. Sectional drawing or perspective view which shows the vicinity of the conductor formed by the selective formation method of the conductor which concerns on 2nd Embodiment using a SEM photograph. Sectional drawing or top view which shows the vicinity of the conductor formed by the selective formation method of the conductor which concerns on 2nd Embodiment using a SEM photograph. Sectional drawing or perspective view which shows the vicinity of the conductor formed by the selective formation method of the conductor which concerns on 2nd Embodiment using a SEM photograph. The figure which shows the process conditions at the time of forming the conductor shown in FIGS. 9-10 as a table | surface. FIG. 13 is a table showing the results obtained by the method for selectively forming conductors according to the second embodiment, classified according to the processing conditions shown in FIG. Sectional drawing which shows the vicinity of the conductor formed by the selective formation method of the conductor concerning 3rd Embodiment using a SEM photograph. Sectional drawing which shows the manufacturing method of the semiconductor device which concerns on 4th Embodiment. Sectional drawing which shows the manufacturing method of the semiconductor device which concerns on 5th Embodiment.

Explanation of symbols

15 ... concave portion, 16 ... silicon substrate (semiconductor substrate, object to be processed), 18a ... first silicon substrate (semiconductor substrate, object to be processed), 18b ... second silicon substrate (semiconductor substrate, object to be processed), 18c ... third silicon substrate (semiconductor substrate, object to be processed), 18d ... fourth silicon substrate (semiconductor substrate, object to be processed), 18 ... solid phase cyclopentadienyl ruthenium (organometallic complex, main conductor) A metal compound containing a component metal), 18a... Cyclopentadienyl ruthenium in a liquid phase (metal compound containing a metal as a main component of a conductor), 18b... Molecular cyclopentadienyl ruthenium (main of a conductor) Metal compound containing metal as component), 19 ... Hydrogen (substance that promotes precipitation of metal from metal compound), 20, 21 ... Ruthenium simple substance (conductor), 22 ... Silicon layer (substrate) Body), 23 ... insulating film (insulating film provided above the substrate body), 23a ... first layer interlayer insulating film (insulating film provided above the substrate body), 23b ... second layer lower layer Side interlayer insulating film (insulating film provided above the substrate body), 23c... Second interlayer insulating film (insulating film provided above the substrate body), 23d. Interlayer insulating film (insulating film provided above the substrate body), 24 ... Au thin film (another conductor different from the conductor forming the inner surface of the recess), 31 ... TiN thin film (the recess Other conductors separate from the conductor that forms the inner surface), 41... Cu alone (conductor), 51... P well (surface layer portion of the substrate body), 52... Trench (formed in the substrate body) Recessed portion where conductor is provided), 57... Plate electrode (Ru film, trench capacitor embedded electrode) 58 ... trench capacitor, 62 ... interlayer insulating film (insulating film provided above the substrate body), 63, 80, 86 ... semiconductor device, 72, 75, 78, 83 ... barrier metal film (on the inner surface of the recess) Other conductors separate from the conductor to be formed), 74, 82... Via holes (recesses provided with conductors formed in an insulating film provided above the substrate body), 76, 84. 77, 81... Upper layer wiring formation recesses (recesses provided with a conductor formed in an insulating film provided above the substrate body), 79, 85... Upper layer Cu wirings

Claims (26)

An object to be processed in which a recess for providing a conductor is formed and a metal compound containing a metal as a main component of the conductor are placed in an atmosphere containing a supercritical fluid, and at least a part of the metal compound is placed in the supercritical state. Dissolved in the fluid,
The metal compound dissolved in the supercritical fluid is brought into contact with the surface of the object to be treated and selectively introduced into the recess, and the metal compound introduced into the recess is aggregated in the recess. And depositing the metal from the metal compound,
Providing the conductor in the recess by solidifying the metal deposited in the recess,
A method for selectively forming a conductor.   Arranging the metal compound in the solid phase under the atmosphere and melting the metal compound in the solid phase to change it into a liquid phase to dissolve a part of the metal compound in the liquid phase in the supercritical fluid. The method for selectively forming a conductor according to claim 1.   The method for selectively forming a conductor according to claim 2, wherein the temperature and pressure of the atmosphere are increased to melt the metal compound to change from a solid phase to a liquid phase.   A part of the metal compound in the liquid phase is contained in the supercritical fluid while the two phases of the phase composed of the metal compound in the liquid phase and the phase composed of the supercritical fluid coexist in the atmosphere while being separated from each other. The method for selectively forming a conductor according to claim 2, wherein the conductive material is dissolved in a material.   The method for selectively forming a conductor according to claim 1, wherein the metal deposited in the recess is solidified by removing the supercritical fluid from the atmosphere.   The method for selectively forming a conductor according to claim 1, wherein the metal deposited in the recess is solidified by lowering at least one of a temperature and a pressure of the atmosphere.   7. The method for selectively forming a conductor according to claim 1, wherein an organometallic complex is used as the metal compound.   The method for selectively forming a conductor according to claim 1, wherein a metal belonging to a platinum group is used as the metal.   It is characterized in that at least one of platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os), and ruthenium (Ru) is used as the metal belonging to the platinum group. The method for selectively forming a conductor according to claim 8.   The method for selectively forming a conductor according to claim 1, wherein copper (Cu) is used as the metal.   The method for selectively forming a conductor according to claim 1, wherein carbon dioxide is used as a raw material of the supercritical fluid.   The metal compound is dissolved in the supercritical fluid until the metal compound is subsaturated, saturated, or supersaturated with respect to the supercritical fluid. The method for selectively forming a conductor according to any one of the above.   The conductor selection according to any one of claims 1 to 12, wherein the metal is deposited in the recess while sequentially filling the inside of the recess with the metal compound from the bottom to the top. Forming method.   The method for selectively forming a conductor according to claim 1, wherein the metal is deposited in the recess until the inside of the recess is filled with the metal.   The conductivity according to any one of claims 1 to 14, wherein the deposition of the metal from the metal compound is promoted by making the density of the supercritical fluid non-uniform and causing density fluctuations. Body selective formation method.   16. The method for selectively forming a conductor according to claim 15, wherein the density of the supercritical fluid is fluctuated by changing at least one of temperature and pressure of the atmosphere to make it nonuniform.   The selective formation of a conductor according to any one of claims 1 to 16, wherein the introduction of the metal compound into the recess and the deposition of the metal from the metal compound are performed in parallel. Method.   The method for selectively forming a conductor according to claim 1, wherein a substance that promotes precipitation of the metal from the metal compound is introduced into the atmosphere.   19. The method for selectively forming a conductor according to claim 18, wherein after the inside of the recess is filled with the metal compound, a substance that promotes precipitation of the metal from the metal compound is introduced into the atmosphere. .   The conductive material according to claim 18 or 19, wherein a substance that enhances the saturation solubility of the metal compound in the supercritical fluid is introduced into the atmosphere as a substance that promotes precipitation of the metal from the metal compound. Body selective formation method.   21. The substance according to claim 18, wherein a substance that functions as a reducing agent for the metal compound is introduced into the atmosphere as a substance that promotes precipitation of the metal from the metal compound. The method for selectively forming a conductor as described in 1.   The method for selectively forming a conductor according to any one of claims 18 to 21, wherein hydrogen is introduced into the atmosphere as a substance that promotes precipitation of the metal from the metal compound.   The conductive material according to any one of claims 1 to 22, wherein at least a surface inside the concave portion of the object to be processed is formed using another conductive material separate from the conductive material. Body selective formation method. A semiconductor substrate on which at least one of a substrate body and an insulating film provided above the substrate body is provided with a recess for providing a conductor, and a metal compound containing a metal that is a main component of the conductor, Placing in an atmosphere containing a critical fluid and dissolving at least a portion of the metal compound in the supercritical fluid;
The metal compound dissolved in the supercritical fluid is brought into contact with the surface of the semiconductor substrate and selectively introduced into the recess, and the metal compound introduced into the recess is aggregated in the recess. Depositing the metal from the metal compound;
Providing the conductor in the recess by solidifying the metal deposited in the recess,
A method for manufacturing a semiconductor device.   25. The method of manufacturing a semiconductor device according to claim 24, wherein the conductor is provided in the recess formed in a surface layer portion of the substrate body to form a buried electrode of a trench capacitor in the surface layer portion of the substrate body. Method.   25. The conductor is provided in the recess formed in the insulating film provided above the substrate body, and at least one of a wiring and a plug is formed in the insulating film. 25. A method for manufacturing a semiconductor device according to 25.

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