Semiconductor device manufacturing method

Abstract

To provide a method of producing a semiconductor device causing few processing failures even when the aspect ratio of a recess is high.SOLUTION: There is provided a method of producing a semiconductor device, including a process of applying metal plating onto the surface of a first electrode 4 by an electroplating method using a semiconductor substrate 1 having a first face 2 whereon a recess 3 is formed, the first electrode 4, formed on the first face 2 along the shape of the recess 3, and a plating solution 5 at least contacting the first electrode 4 and including a solution containing metal ions to be plated and an electrolyte, and pieces of supercritical fluid. The median value of the particle size distribution of the pieces of supercritical fluid is larger than a first size a of the recess 3, provided that the aspect ratio of the recess 3 is expressed by the ratio of a second size of the recess 3 relative to the first size a of the recess 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] The diameter of TSV (through silicon via) via holes is getting smaller every year as the integration density of semiconductor elements increases, and in the future, TSVs with a diameter of φ5μm or less will be required. For example, if the chip thickness is 50μm, the aspect ratio in that case will reach 10 or more. To fill such high aspect ratio via holes without gaps using electroplating, a bottom-up growth technology is required that controls the plating speed at the bottom of the hole faster than on the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6400512 [Non-patent literature]

[0004] [Non-Patent Document 1] Kazuhito Higuchi et al., Electrochemical Investigation of Cu Electroplating with Supercritical CO2 Emulsion Using a Rotating Disk Electrode under High Pressure, J.Electrochem.Soc., 167 162506 (2020) [Non-Patent Document 2] Aya Mizushima et al., Nanograin deposition via an electroplating reaction in an emulsion of dense carbon dioxide in a nickel electroplating solution using nonionic fluorinated surfactant, Surface & Coatings Technology 194 (2005) 149-156 [Non-Patent Document 3] Andrew J. Worthen et al., Carbon Dioxide-in-Water Foams Stabilized with Nanoparticles and Surfactant Acting in Synergy, AIChE Journal, September 2013 Vol.59,No.9 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the invention is to provide a manufacturing method for a semiconductor device with few processing defects even when the aspect ratio of a recess is high. [Means for solving the problem]

[0006] According to the embodiment, a semiconductor substrate having a first surface on which a recess is provided, and a semiconductor device having a shape of the recess on the first surface a first electrode formed along a line; and a metal ion to be plated and a By electroplating using a plating solution containing an electrolyte and a mass of a supercritical fluid, A method for manufacturing a semiconductor device is provided, the method including plating a surface of the first electrode with a metal. When the aspect ratio of the recess is expressed as the ratio of the second dimension of the recess to the first dimension of the recess, The median of the particle size distribution of the fluid mass is greater than the first dimension of the recess. The second dimension is the depth of the recess. The first dimension is the dimension of the recess in a direction intersecting the depth direction. [Brief description of the drawings]

[0007] [Figure 1] 1A to 1C are cross-sectional views illustrating an example of a process included in a method according to an embodiment. [Diagram 2] A graph showing the volume distribution of micellar particle size in supercritical CO2. [Diagram 3] 1A to 1C are cross-sectional views illustrating an example of a process included in a method according to an embodiment. [Figure 4] 1A to 1C are cross-sectional views illustrating an example of a process included in a method according to an embodiment. [Diagram 5] 1 is a graph showing the current-voltage characteristics of a plating solution when the volume ratio of supercritical CO2 is changed. [Figure 6] 4A to 4C are cross-sectional views showing an outline of a plating process according to a reference example. [Figure 7] 4A to 4C are cross-sectional views showing an outline of a plating process according to a reference example. [Figure 8] 4A to 4C are cross-sectional views showing an outline of a plating process according to a reference example. [Figure 9] FIG. 2 is a diagram showing a schematic configuration of an example of an electroplating apparatus used in the method of the embodiment. [Figure 10] 10 is a cross-sectional view showing a schematic configuration of an example of a cathode unit of the electroplating apparatus shown in FIG. [Figure 11] FIG. 4 is a schematic diagram showing an example of a semiconductor substrate electroplated by a method of a comparative example. [Figure 12] FIG. 4 is a schematic diagram showing another example of a semiconductor substrate electroplated by a method of the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A method for manufacturing a semiconductor device according to an embodiment includes electroplating a surface of the first electrode with metal plating by using a plating solution that includes a semiconductor substrate having a first surface with a recess, a first electrode formed on the first surface along the shape of the recess, a solution containing a metal ion to be plated and an electrolyte, and a mass of supercritical fluid, the plating solution being in contact with at least the first electrode. When the aspect ratio of the recess is expressed as a ratio of a second dimension of the recess to a first dimension of the recess, the median value in the particle size distribution of the mass of supercritical fluid is greater than the first dimension of the recess. The second dimension of the recess is, for example, the depth of the recess. The first dimension of the recess is, for example, a dimension in a direction intersecting (for example, perpendicular to) the depth direction of the recess.

[0009] Electroplating is performed, for example, by immersing an anode and a cathode in a reaction tank containing a plating solution and using a first electrode as the cathode.

[0010] The method of the embodiment will be described with reference to FIGS. The semiconductor may be selected from, for example, silicon (Si); germanium (Ge); semiconductors made of compounds of group III and group V elements, such as gallium arsenide (GaAs) and gallium nitride (GaN); and silicon carbide (SiC). According to one example, the semiconductor substrate includes silicon. Note that the term "group" as used herein refers to the "group" of the short periodic table.

[0011] The semiconductor substrate is, for example, a semiconductor wafer. The semiconductor wafer may be doped with impurities, and may have semiconductor elements such as transistors and diodes formed thereon. The main surface of the semiconductor wafer may be parallel to any crystal plane of the semiconductor. The semiconductor wafer may be, for example, a silicon wafer whose main surface is a (100) plane, or a silicon wafer whose main surface is a (110) plane.

[0012] As shown in Fig. 1, a recess 3 is provided in a main surface 2 along the xy plane, which is a first surface of a semiconductor substrate 1. The recess 3 is, for example, a via hole. The recess 3 has a depth in the thickness direction of the semiconductor substrate 1 along the z-axis direction. When the diameter (hole diameter) of the recess 3 is a, the aspect ratio of the recess 3 is expressed as the ratio of the depth (second dimension) to the diameter a (first dimension). A plurality of recesses 3 may be provided in the main surface 2 along the xy plane of the semiconductor substrate 1.

[0013] The first electrode 4 is formed on the main surface 2 along the xy plane of the semiconductor substrate 1 along the shape of the recess 3. In other words, the first electrode 4 is formed on the main surface 2 along the xy plane of the semiconductor substrate 1 and on the sidewall surface and bottom surface that define the recess 3. The first electrode 4 can function as an adhesion layer that improves adhesion between the semiconductor substrate 1 and the plating layer. The first electrode 4 can be formed, for example, from a Ti / Cu or Ti / Ni / Pd laminated film. Note that Cr can also be used instead of Ti. The first electrode 4 is formed, for example, by sputtering, vapor deposition, etc. In addition, when plating is performed in a pattern, a resist pattern having openings only in the areas to be plated may be formed on the first electrode.

[0014] The plating solution 5 is in contact with at least the first electrode 4. The plating solution 5 is, for example, a mixed plating solution containing a solution containing ions of a metal to be plated and an electrolyte (hereinafter referred to as a first solution) and a mass of a supercritical fluid. As an example of the metal to be plated, at least one selected from Cu, Ni, Ag, a Cu alloy, a Ni alloy, and an Ag alloy can be used. As an example of the first solution, a copper sulfate plating solution containing copper sulfate pentahydrate and sulfuric acid, a copper pyrophosphate plating solution containing copper pyrophosphate and potassium pyrophosphate, a nickel sulfamate plating solution containing nickel sulfamate and boron, etc. can be mentioned.

[0015] A supercritical fluid is a fluid that does not belong to any of the solid, liquid, or gas states in the phase diagram of a substance determined by temperature and pressure, and its main characteristics are high diffusivity, high density, zero surface tension, etc., and nano-level permeability and high-speed reaction can be expected compared to processes using normal liquids. An example of a supercritical fluid is supercritical CO2. The critical points at which CO2 becomes supercritical are 31°C and 7.4 MPa, and it becomes a supercritical fluid at temperatures and pressures above these.

[0016] An example of a supercritical fluid mass is a micelle of supercritical CO2.

[0017] The plating solution 5 may contain at least one of an organic material compatible with supercritical CO2 and water and a surfactant as an additive. Supercritical CO2 does not mix with an electrolyte-containing aqueous solution, but adding the above-mentioned additive to the solution causes emulsification, and a supercritical CO2 emulsion (SCE) can be obtained. An example of a surfactant is polyethylene oxide alkyl ether. On the other hand, an example of an organic material compatible with supercritical CO2 and water is polyethylene glycol. The particle size of supercritical CO2 micelles tends to be small when an additive capable of reducing the interfacial tension of supercritical CO2 is used.

[0018] In the plating solution 5, the volume ratio of the supercritical fluid in the total volume of the first solution and the supercritical fluid can be 50% by volume or less. This allows stable electroplating to be realized. If the volume ratio of the supercritical fluid exceeds 50% by volume, the first solution is dispersed in the supercritical fluid to form an emulsion, and there is a possibility that the current will not flow stably. In addition, in a range in which the volume ratio of the supercritical fluid is 50% by volume or less, the smaller the volume ratio of the supercritical fluid, the smaller the agglomerate particle size of the supercritical fluid tends to be. It is preferable that the volume ratio of the supercritical fluid in the total volume of the first solution and the supercritical fluid is 5% by volume or more. This allows the reduction of the kinetic viscosity of the plating solution 5 and the increase of the diffusion constant of the metal to be plated to be realized. Therefore, it is preferable that the volume ratio of the supercritical fluid in the total volume of the first solution and the supercritical fluid is 5% by volume or more and 50% by volume or less. A more preferable range is 5% by volume or more and 30% by volume or less.

[0019] The median (D50) in the particle size distribution of the supercritical fluid mass is made larger than the first dimension of the recess. On the other hand, when the recess is a via hole, the first dimension of the recess is the diameter a of the via hole. When the recess is a groove, the aspect ratio of the recess is expressed as the ratio of the depth (second dimension) of the groove to the width (first dimension) of the groove, so the first dimension is the width of the groove. For example, when a groove is formed along the y-axis direction of the main surface along the xy plane of the semiconductor substrate 1, the width of the groove along the x-axis direction, that is, the shorter width, is the first dimension. The semiconductor substrate 1 can be provided with a via hole, a groove, or both a via hole and a groove. FIG. 2 shows the relationship between the D50 value in the particle size distribution of the supercritical CO2 micelles and the diameter a of the recess 3. By making the particle size (D50) of the supercritical CO2 micelles larger than the diameter a, the concentration of the supercritical CO2 micelles in the recess 3 can be made lower than the concentration of the supercritical CO2 micelles outside the recess 3 (for example, the main surface 2 of the semiconductor substrate 1). FIG. 5 shows the current-voltage characteristics of plating solution 5 when the volume ratio of supercritical CO2 in plating solution 5 is changed. The horizontal axis in FIG. 5 is overpotential η (V), and the vertical axis is current density J (mA / cm 2) The current-voltage curve of plating solution 5 containing 10 volume % of supercritical CO2 is C1, the current-voltage curve of plating solution 5 containing 30 volume % of supercritical CO2 is C2, and the current-voltage curve of plating solution 5 not containing supercritical CO2 is C3. As is clear from FIG. 5, the current density of current-voltage curve C1 and current-voltage curve C2 is lower than that of current-voltage curve C3. This shows that the electrodeposition reaction can be suppressed by increasing the concentration of supercritical CO2 in plating solution 5. Therefore, by lowering the concentration of supercritical CO2 micelles in recess 3, the effect of suppressing the electrodeposition reaction by supercritical CO2 can be reduced. Therefore, the plating speed in recess 3 can be increased.

[0020] On the other hand, supercritical CO2 can reduce the kinetic viscosity of the plating solution and increase the diffusion constant of the ions of the metal to be plated. As a result, the supply of ions into the recesses 3 can be promoted, so that the deposition of the plating layer can be continued without causing a depletion of ions in the recesses 3. For example, as illustrated in Figure 3, the deposition of the plating layer 6 progresses upward along the z-axis direction from the bottom that defines the recesses 3, and as illustrated in Figure 4, the plating layer 6 can fill the recesses 3 without any gaps.

[0021] As described above, by making the median value in the particle size distribution of the supercritical CO2 micelles larger than the first dimension (e.g., diameter a) of the recess, the concentration of the supercritical CO2 micelles in the recess 3 can be made lower than the concentration of the supercritical CO2 micelles outside the recess 3. As a result, the plating speed in the recess 3 can be increased. In addition, since the supply of ions into the recess 3 can be promoted, the deposition of the plating layer can be continued without causing a depletion of ions in the recess 3. Therefore, processing defects when the aspect ratio of the recess 3 is increased can be reduced.

[0022] The method for measuring the particle size distribution of the supercritical fluid agglomerates is described below. A pressure vessel equipped with a transmission window that allows optical measurement from the outside is used to optically observe the supercritical fluid agglomerates in the plating solution 5 inside the vessel. The particle size of the agglomerates can be obtained by taking optical microscope photographs and analyzing the photographed data with Image J software (see, for example, the left column on page 3493 of Non-Patent Document 3). In addition, for example, a high-pressure observation cell with two sapphire windows (see page 150 and FIG. 2 of Non-Patent Document 2) can be used as the pressure vessel.

[0023] The aspect ratio of the recess is not particularly limited and can be any value greater than 0. An example is 1 or greater.

[0024] The method of the embodiment may include a step of removing oxides on the surface of the first electrode before the electroplating step, and may also include a cleaning step and a drying step after the electroplating step.

[0025] It has been proposed to add an organic material as a plating inhibitor to the plating solution when filling a recess in a semiconductor substrate with a conductive material by electroplating. An example of the organic material is polyethylene glycol (PEG). Such a reference example will be described with reference to Figs. 6 to 8. The same reference numerals are used for the same members as those shown in Fig. 1, and the description will be omitted. As shown in Fig. 6, a plating inhibitor 7 made of an organic material is adsorbed on the main surface along the xy plane of the semiconductor substrate 1 and on the first electrode 4 formed on the sidewall surface and bottom surface defining the recess 3. Since the adsorption speed depends on the diffusion of the inhibitor 7, the amount of the inhibitor adsorbed near the bottom of the recess 3 is smaller than the amount of the inhibitor adsorbed near the upper end of the opening of the recess 3. As a result, as shown in Fig. 7, a current 8 is concentrated near the bottom of the recess 3, and as a result, the deposition speed of the plating layer 6 at the bottom of the recess 3 is increased. Thereafter, as shown in Fig. 8, the inhibitor 7 near the bottom of the recess 3 is buried in the plating layer 6, and the current 9 is further concentrated, causing the plating layer 6 to grow. This series of steps is called a positive feedback model. On the other hand, although the metal ion concentration in the plating solution is higher than that of the inhibitor 7, the supply of metal ions depends on diffusion. Therefore, when the aspect ratio of the recess 3 increases, metal ions are depleted near the bottom of the recess 3 where the convection of the plating solution does not reach, resulting in a processing defect in which it is practically impossible to form a plating layer.

[0026] An example of an electroplating apparatus used in the method of the embodiment will be described with reference to FIGS.

[0027] The electroplating apparatus 10 includes a carbon dioxide supplying section 20, a temperature control pump 30, a plating processing section 40, a discharge section 60, and a control section 100 that controls these sections in a coordinated manner.

[0028] The carbon dioxide supply unit 20 includes a carbon dioxide cylinder 21 in which high-pressure carbon dioxide is stored, a supply pipe 22 having one end connected to the carbon dioxide cylinder 21 and the other end connected to a temperature control pump 30, and a supply valve 23 that controls the flow rate of the supply pipe 22.

[0029] The temperature control pump 30 is equipped with a cooler 31 that cools and liquefies the carbon dioxide gas supplied from the supply piping 22, a compressor 32 that compresses the liquefied carbon dioxide, a heater 34 that heats the liquefied carbon dioxide, and a pressure gauge 33 connected to the outlet side of this heater 34.

[0030] The heater 34 heats the carbon dioxide to a temperature equal to or higher than its critical temperature of 31.1° C. The compressor 32 pressurizes the liquefied carbon dioxide to a predetermined pressure, for example, to a pressure equal to or higher than its critical pressure of 7.38 MPa.

[0031] The plating processing section 40 includes a thermostatic bath 41, a reaction tank 42 arranged in the thermostatic bath 41 and containing plating solution L, a supply pipe 43 having one end connected to the outlet of the heater 34 and the other end connected to the inside of the reaction tank 42, a control valve 44 for controlling the flow rate of the supply pipe 43, an outlet pipe 45 having one end connected to the inside of the reaction tank 42 and the other end connected to an exhaust section 60, a DC constant current source 46 for supplying electricity, an anode 47 connected to the positive electrode side of the DC constant current source 46 and arranged in the reaction tank 42, and a cathode section 50 connected to the negative electrode side of the DC constant current source 46 and arranged in the reaction tank 42.

[0032] A stainless steel pressure vessel with an inner wall coated with Teflon (registered trademark) was used as the reaction vessel 42. The reaction vessel 42 contains a plating solution 5.

[0033] A plate of the metal to be plated is mainly used as the anode 47. A lead that is connected to the positive pole of a power source is connected to the anode 47 for current flow.

[0034] As shown in FIG. 10, the cathode section 50 includes a support plate 51, a semiconductor substrate 1 and a first electrode 4 arranged on the support plate 51, a claw portion 52, and a lead 53. The semiconductor substrate 1 and the first electrode 4 have the configuration shown in FIG. 1. The claw portion 52 is a metal spring fixed on the support plate 51. The claw portion 52 holds the periphery of the side surface and the main surface of the semiconductor substrate 1 on which the first electrode 4 is formed, so that the semiconductor substrate 1 and the first electrode 4 are pressed against the support plate 51. In addition, the claw portion 52 contacts the first electrode 4, so that the claw portion 52 and the first electrode 4 are electrically connected. The lead 53 is accommodated in the space inside the support plate 51, and one end is electrically connected to the claw portion 52 and the other end is electrically connected to the negative electrode of the power source. Electricity is applied to the first electrode 4 from the negative electrode of the power source through the lead 53 and the claw portion 52.

[0035] The exhaust section 60 includes an exhaust pipe 61 having one end connected to the outlet pipe 45 and the other end connected to a processing vessel 64 described later, a branch pipe 62 branching off from the exhaust pipe 61, a back pressure control valve 63 provided on the branch pipe 62, and the processing vessel 64.

[0036] An example of electroplating using the electroplating apparatus 10 configured in this manner will be described below. Example 1 A silicon wafer was prepared as the semiconductor substrate 1. A via with a hole size (diameter) a of 10 μm and a depth of 50 μm (aspect ratio of 5) was formed as a recess 3 on the main surface of the semiconductor substrate 1 by, for example, dry etching. A first electrode 4 consisting of a laminated film of a Ti layer with a thickness of 100 nm and a Cu layer with a thickness of 500 nm was formed on the main surface of the semiconductor substrate 1 by sputtering. The Cu layer is located on the front side of the first electrode 4 and contacts the plating solution 5. Cr may be used instead of Ti. The base material obtained as described above was immersed in a 10 wt % H2SO4 aqueous solution for 1 minute as a plating pretreatment. The purpose of this pretreatment is to remove the natural oxide film formed on the surface of the first electrode 4. It is preferable to appropriately change the type and composition of the pretreatment solution that can reliably remove the oxide film, and the treatment time, depending on the growth state of the oxide film.

[0037] The substrate and the anode were placed in a reaction tank 42. A pure Cu plate was used as the anode. The plating solution 5 was placed in the reaction tank 42, and the lid of the reaction tank 42 was closed and sealed. As a first solution, an aqueous solution containing 250 g / L of copper sulfate, 50 mL / L of sulfuric acid, 60 mg / L of Cl ions, and 1 g / L of polyethylene glycol was prepared.

[0038] A 4N liquefied CO2 cylinder was used for CO2, and the temperature was adjusted to 40°C, and the inside of the reaction tank 42 was adjusted to 10 MPa by a high-pressure pump and back pressure control. The reaction tank 42 was also placed in a thermostatic tank 41 and controlled to 40°C. The pressure in the supply pipe 43 connected to the control valve 44 was also 10 MPa. The volume ratio of the first solution to CO2 was adjusted to 7:3, that is, CO2 was 30 volume%. The volume ratio of the first solution to CO2 is calculated by subtracting the volume of the first solution from the internal volume of the reaction tank 42 and setting the volume of CO2 as the volume of CO2. The critical point at which CO2 becomes supercritical is 31°C and 7.4 MPa, but in this embodiment, a margin of critical temperature + 9°C and critical pressure + 2.6 MPa was provided so that the CO2 in the reaction tank 42 is surely in a supercritical state. These values ​​can be appropriately determined in consideration of the temperature and pressure distribution in the reaction tank 42.

[0039] It was confirmed that the pressure and temperature in the reaction tank 42 reached the specified values ​​and stabilized. A plating solution 5, which was a mixture of the first solution and micelles of supercritical CO2, was present in the reaction tank 42. The median (D50) of the particle size distribution of the supercritical CO2 micelles was 30 μm, which was larger than the pore size a of the recesses 3.

[0040] The power supply for the DC constant current source 46 was turned on, and a plating current was applied at a constant current for a predetermined time. The current density of the plating current was a cathode current density of 10 mA / cm 2 After applying the current for a specified time, the pressure inside the reaction vessel was returned to normal pressure, and the substrate on which the Cu coating was formed was taken out, washed with water, and dried.

[0041] There was no processing defect in the Cu plating formed in the recess 3. Example 2 As the first solution, an aqueous solution containing 370 g / L of nickel sulfate, 90 g / L of nickel chloride, 100 g / L of boric acid, and 10 g / L of polyethylene oxide alkyl ether was prepared. A pure Ni plate was prepared as the anode.

[0042] Electroplating was carried out in the same manner as in Example 1, except for using the first solution and the anode. No processing defects occurred in the Ni plating formed in the recesses 3. (Comparative Example) Electroplating was performed in the same manner as in Example 1, except that the temperature in the reaction tank 42 was set to 50°C and the median particle size distribution (D50) of the supercritical CO micelles was set to 5 μm, making it smaller than the pore size a of the recess 3. However, processing defects occurred in the Cu plating formed in the recess 3.

[0043] As examples of processing defects in the comparative example, as shown in Fig. 11, voids 101 were generated in the plating layer 6 in the recesses 3, and as shown in Fig. 12, seams 102 were generated in the plating layer 6 in the recesses 3. This is presumably because the micelle concentration in the recesses 3 did not decrease, and therefore the plating speed in the recesses 3 did not become relatively faster than that outside the recesses 3.

[0044] The method for manufacturing a semiconductor device according to the embodiment described above includes a semiconductor substrate having a first surface with a recess, a first electrode formed on the first surface along the shape of the recess, and electroplating a surface of the first electrode using a plating solution that is in contact with at least the first electrode and contains a solution containing a metal ion to be plated and an electrolyte and a mass of supercritical fluid. When the aspect ratio of the recess is expressed as a ratio of a second dimension of the recess to a first dimension of the recess, the median of the particle size distribution of the mass of supercritical fluid is larger than the first dimension of the recess. According to such a method for manufacturing a semiconductor device, it is possible to reduce defects in electroplating even when the aspect ratio of the recess is high.

[0045] Although several embodiments of the present invention have been described, these embodiments are presented by way of example only. These novel embodiments are not intended to limit the scope of the invention. It is possible to implement the present invention in various other forms, and various modifications are possible without departing from the spirit and scope of the present invention. Omissions, substitutions, and modifications may be made. These embodiments and their modifications are within the scope of the invention and The invention is included in the abstract and in the scope of the claims and their equivalents. . The invention as described in the claims of the present application as originally filed is set forth below. [1] A semiconductor substrate having a first surface with a recess; a first electrode formed on the first surface along the shape of the recess; a plating solution in contact with at least the first electrode, the plating solution including a solution containing a metal ion to be plated and an electrolyte, and a mass of a supercritical fluid, is used to perform metal plating on a surface of the first electrode by an electroplating method, A method for manufacturing a semiconductor device, wherein, when an aspect ratio of the recess is expressed as a ratio of a second dimension of the recess to a first dimension of the recess, a median of particle size distribution of the supercritical fluid lumps is larger than the first dimension of the recess. [2] The mass of supercritical fluid is supercritical CO 2 The method for producing a semiconductor device according to [1], wherein the micelle is [3] The method for manufacturing a semiconductor device according to [1] or [2], wherein the recess is at least one of a hole and a groove provided on the first surface of the semiconductor substrate. [4] The method for manufacturing a semiconductor device according to [3], wherein the first dimension of the recess is a diameter of the hole or a width of the groove. [5] The method for manufacturing a semiconductor device according to any one of [1] to [4], wherein a volume ratio of the supercritical fluid to a total volume of the solution and the supercritical fluid is 50 volume % or less. [6] The method for manufacturing a semiconductor device according to any one of [1] to [5], wherein the metal ions to be plated are ions of at least one metal selected from the group consisting of Cu, Ni, and Ag. [7] The method for manufacturing a semiconductor device according to any one of [1] to [6], wherein the potential of the first electrode is negative. [Explanation of symbols]

[0046] Reference Signs List 1...semiconductor substrate, 2...first surface, 3...recess, 4...first electrode, 5...plating solution, 6...plating layer, 7...inhibitor, 8...current, 9...current, 10...electroplating apparatus, 20...carbon dioxide supply section, 21...carbon dioxide cylinder, 22...supply piping, 23...supply valve, 30...temperature control pump, 31...cooler, 32...compressor, 33...pressure gauge, 34...heater, 40...plating section, 41...constant temperature bath, 42...reaction bath, 44...control valve, 45...outlet piping, 46...DC constant current source, 47...anode, 50...cathode section, 51...support plate, 52...claw section, 53...lead, 60...discharge section, 61...discharge piping, 62...branch piping, 63...backpressure regulating valve, 64...processing vessel, 100...control section, 101...void, 102...seam, a...first dimension.

Claims

1. a semiconductor substrate having a first surface with a recess; a first electrode formed on the first surface along the shape of the recess; a plating solution in contact with at least the first electrode, the plating solution including a solution containing a metal ion to be plated and an electrolyte, and a mass of a supercritical fluid, is used to perform metal plating on a surface of the first electrode by an electroplating method, when an aspect ratio of the recess is expressed as a ratio of a second dimension of the recess to a first dimension of the recess, a median of a particle size distribution of the supercritical fluid mass is larger than the first dimension of the recess; the second dimension is a depth of the recess; A method for manufacturing a semiconductor device, wherein the first dimension is a dimension in a direction intersecting a depth direction of the recess.

2. The mass of supercritical fluid is supercritical CO 2 The method for producing a semiconductor device according to claim 1 , wherein the micelle is a micelle of the formula (I).

3. 3. The method of claim 1, wherein the recess is at least one of a hole and a groove provided on the first surface of the semiconductor substrate.

4. The method for manufacturing a semiconductor device according to claim 3 , wherein the first dimension of the recess is a diameter of the hole or a width of the groove.

5. 5. The method for manufacturing a semiconductor device according to claim 1, wherein a volume ratio of said supercritical fluid to a total volume of said solution and said supercritical fluid is 50 volume % or less.

6. 6. The method for manufacturing a semiconductor device according to claim 1, wherein the metal ions to be plated are ions of at least one metal selected from the group consisting of Cu, Ni, and Ag.

7. 7. The method for manufacturing a semiconductor device according to claim 1, wherein the potential of the first electrode is negative.

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