Semiconductor device manufacturing method and manufacturing system

Abstract

To reduce residue in an air gap.SOLUTION: A method for manufacturing a semiconductor device includes the steps a), b), and c). In the step a), a sacrificial material is embedded in a recess formed in a substrate. In the step b), the recess in which the sacrificial material is embedded is covered with a sealing film. In the step c), a process gas is turned into plasma outside the recess, and active species contained in the plasma are supplied to the sacrificial material through the sealing film, thereby decomposing the sacrificial material in the recess and removing the sacrificial material in the recess through the sealing film.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] Various aspects and embodiments of the present disclosure relate to a method and a manufacturing system for manufacturing a semiconductor device.

Background Art

[0002] For example, Patent Document 1 below discloses "a method for manufacturing a semiconductor device including a first lamination step of laminating a thermally decomposable organic material on a substrate having a recess, a second lamination step of laminating a silicon nitride film on the organic material, and a desorption step of heating the substrate to a predetermined temperature to thermally decompose the organic material and desorb the organic material under the silicon nitride film through the silicon nitride film to form an air gap between the silicon nitride film and the recess, and in the second lamination step, the silicon nitride film is laminated using microwave plasma while the temperature of the substrate is maintained at 200 [°C] or lower."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a method and a manufacturing system for manufacturing a semiconductor device capable of reducing residues in an air gap.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a method for manufacturing a semiconductor device, including step a), step b), and step c). In step a), a sacrificial material is embedded in a recess formed in a substrate. In step b), the recess in which the sacrificial material is embedded is covered with a sealing film. In step c), a processing gas is plasmaized outside the recess, and active species contained in the plasma are supplied to the sacrificial material through the sealing film, so that the sacrificial material in the recess is decomposed and the sacrificial material in the recess is removed through the sealing film.

Advantages of the Invention

[0006] According to various aspects and embodiments of the present disclosure, residues in the air gap can be reduced.

Brief Description of the Drawings

[0007]

Figure 1

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[0008] Hereinafter, embodiments of a method for manufacturing a semiconductor device and a manufacturing system disclosed will be described in detail with reference to the drawings. Note that the method for manufacturing a semiconductor device and the manufacturing system disclosed are not limited by the following embodiments.

[0009] In the technology of Patent Document 1, by heating a substrate, an organic material embedded in a recess is thermally decomposed and removed through a sealing film, so that an air gap is formed in the recess covered with the sealing film. However, depending on the temperature at which the substrate is heated, the organic material may not be sufficiently removed, and the organic material may remain in the recess as a residue. If a residue remains in the recess, the volume of the air gap becomes smaller than the desired volume. Further, if the amount of residue varies between the air gaps, variations in volume occur between the plurality of air gaps. Therefore, it is desired to suppress the residue in the air gap.

[0010] Therefore, the present disclosure provides a technique capable of reducing the residue in the air gap.

[0011] [Configuration Example of Manufacturing System 10] FIG. 1 is a system configuration diagram showing an example of a manufacturing system 10 according to an embodiment of the present disclosure. The manufacturing system 10 includes a VTM (Vacuum Transfer Module) 11, a plurality of LLM (Load Lock Modules) 12, and an EFEM (Equipment Front End Module) 13. A film forming apparatus 20, a plasma processing apparatus 30, a heating apparatus 40, and a plasma processing apparatus are connected to the side wall of the VTM 11 via a gate valve G. In the example of FIG. 1, one film forming apparatus 20, one plasma processing apparatus 30, one heating apparatus 40, and one plasma processing apparatus 50 are connected to the VTM 11, respectively, but the disclosed technology is not limited thereto. As another form, a plurality of at least one of the film forming apparatus 20, the plasma processing apparatus 30, the heating apparatus 40, and the plasma processing apparatus 50 may be connected to the VTM 11.

[0012] The film forming apparatus 20 embeds a sacrificial material in a recess formed in a substrate. In the present embodiment, the sacrificial material is a thermally decomposable organic material. The film forming apparatus 20 is an example of a first processing apparatus.

[0013] The plasma processing apparatus 30 generates plasma and irradiates the substrate with active species and the like contained in the generated plasma to remove unnecessary sacrificial material formed on the substrate. Further, the plasma processing apparatus 30 forms a sealing film on the recess in which the sacrificial material is embedded. The plasma processing apparatus 30 is an example of a second processing apparatus.

[0014] The heating apparatus 40 heats the substrate in which the sacrificial material is embedded in the recess to thermally decompose the sacrificial material and remove the sacrificial material through the sealing film.

[0015] The plasma processing apparatus 50 generates plasma and irradiates the inside of the recess of the substrate through the sealing film with active species and the like contained in the generated plasma to remove residues of the sacrificial material remaining in the recess. The plasma processing apparatus 50 is an example of a third processing apparatus.

[0016] On the other side wall of VTM11, a plurality of LLM12 are connected via gate valve G. In the example of FIG. 1, two LLM12 are connected to VTM11, but the number of LLM12 connected to VTM11 may be more than two or may be one.

[0017] A transfer robot 110 is arranged inside VTM11. The transfer robot 110 transfers the substrate among the film forming apparatus 20, the plasma processing apparatus 30, the heating apparatus 40, the plasma processing apparatus 50, and the LLM12. The inside of VTM11 is maintained at a predetermined pressure atmosphere lower than the atmospheric pressure.

[0018] One side wall of each LLM12 is connected to VTM11 via gate valve G, and the other side wall is connected to EFEM13 via gate valve G. When the substrate is carried into the LLM12 from the EFEM13 via the gate valve G, the gate valve G is closed, and the pressure inside the LLM12 is reduced to a pressure approximately the same as the pressure inside the VTM11. Then, the gate valve G is opened, and the substrate inside the LLM12 is carried out into the VTM11 by the transfer robot 110.

[0019] Also, with the pressure inside the LLM12 being approximately the same as the pressure inside the VTM11, the substrate is carried into the LLM12 from the VTM11 via the gate valve G by the transfer robot 110, and the gate valve G is closed. Then, the pressure inside the LLM12 is increased to a pressure approximately the same as the pressure inside the EFEM13. Then, the gate valve G is opened, and the substrate inside the LLM12 is carried out into the EFEM13.

[0020] On the side wall of the EFEM13 opposite to the side wall where the gate valve G is provided, a plurality of load ports 14 are provided. A container such as a FOUP (Front Opening Unified Pod) capable of accommodating a plurality of substrates is connected to each load port 14. Note that an aligner module or the like for changing the orientation of the substrate may be provided inside the EFEM13.

[0021] Inside the EFEM 13, it is, for example, at atmospheric pressure. Inside the EFEM 13, a transfer robot 130 is provided. The transfer robot 130 transfers the substrate between the LLM 12 and the container connected to the load port 14. On the upper part of the EFEM 13, an FFU (Fan Filter Unit) or the like is provided, and dry air from which particles and the like have been removed is supplied into the EFEM 13 from above, and a downflow is formed inside the EFEM 13. In this embodiment, the inside of the EFEM 13 is at atmospheric pressure, but as another form, the pressure inside the EFEM 13 may be controlled to be a positive pressure. Thereby, the intrusion of particles and the like from the outside into the EFEM 13 can be suppressed.

[0022] The control device 15 includes a memory, a processor, and an input / output interface. Data such as a control program and a processing recipe are stored in the memory. The processor reads the control program from the memory and executes it, and controls each part of the manufacturing system 10 via the input / output interface based on the recipe and the like stored in the memory.

[0023] [Configuration example of the film forming apparatus 20] FIG. 2 is a diagram showing an example of the film forming apparatus 20. The film forming apparatus 20 includes a chamber 21, an exhaust mechanism 22, a gas supply unit 23, a shower head 25, and a stage 26. In this embodiment, the film forming apparatus 20 is, for example, a CVD (Chemical Vapor Deposition) apparatus.

[0024] The exhaust mechanism 22 includes a vacuum pump that exhausts the gas inside the chamber 21 and a pressure adjustment valve that adjusts the pressure inside the chamber 21. The inside of the chamber 21 is controlled to a vacuum atmosphere with a predetermined pressure by the exhaust mechanism 22.

[0025] In the chamber 21, a gas supply unit 23 for supplying a plurality of types of raw material monomers is connected via a shower head 25. In the present embodiment, the plurality of types of raw material monomers are, for example, isocyanate and amine. Isocyanate is an example of the first monomer, and amine is an example of the second monomer. The gas supply unit 23 includes a raw material supply source 230a, a raw material supply source 230b, a vaporizer 231a, and a vaporizer 231b. The raw material supply source 230a stores, for example, a liquid of isocyanate. The raw material supply source 230b stores, for example, a liquid of amine.

[0026] The vaporizer 231a vaporizes the liquid of isocyanate supplied from the raw material supply source 230a. The vapor of isocyanate vaporized by the vaporizer 231a is introduced into the shower head 25 via a pipe 24a. Further, the vaporizer 231b vaporizes the liquid of amine supplied from the raw material supply source 230b. The vapor of amine vaporized by the vaporizer 231b is introduced into the shower head 25 via a pipe 24b.

[0027] The shower head 25 is provided, for example, at the upper part of the chamber 21, and a large number of discharge ports are formed on the lower surface. The shower head 25 discharges the vapor of isocyanate introduced via the pipe 24a and the vapor of amine introduced via the pipe 24b into the chamber 21 in a shower form from separate discharge ports.

[0028] In the chamber 21, a stage 26 is provided. The stage 26 has a temperature adjustment mechanism (not shown). A substrate W carried into the chamber 21 through an opening 21a formed in the side wall of the chamber 21 is placed on the stage 26. The opening 21a is opened and closed by a gate valve G. The stage 26 has a temperature adjustment mechanism, and the temperature of the substrate W is controlled by the temperature adjustment mechanism so as to be a temperature suitable for vapor phase polymerization of the raw material monomers supplied from the gas supply unit 23. The temperature suitable for vapor phase polymerization can be determined according to the type of the raw material monomers. The temperature suitable for vapor phase polymerization is, for example, a temperature within the range of 60°C to 100°C.

[0029] Using such a film forming apparatus 20, a polymer organic film is formed on the surface of the substrate W by causing a vapor phase polymerization reaction of two types of raw material monomers on the surface of the substrate W. When the two types of raw material monomers are isocyanate and amine, a polymer organic film having a polyurea bond is formed on the surface of the substrate W. The polymer organic film is an example of a sacrificial material.

[0030] [Configuration example of plasma processing apparatus 30] FIG. 3 is a diagram showing an example of the plasma processing apparatus 30. The plasma processing apparatus 30 has a chamber 31 formed of a conductive material. The chamber 31 is grounded. An exhaust mechanism 32 is connected to the chamber 31. The exhaust mechanism 32 has a pressure adjustment valve. The exhaust mechanism 32 exhausts the gas in the chamber 31 and controls the pressure adjustment valve so that the pressure in the chamber 31 becomes a predetermined pressure.

[0031] A stage 33 on which the substrate W is placed is provided in the chamber 31. The substrate W carried into the chamber 31 through an opening 31a formed in the side wall of the chamber 31 is placed on the stage 33. The opening 31a is opened and closed by a gate valve G. A heater 33a for heating the substrate W is provided in the stage 33. Further, the stage 33 is electrically connected to the bottom of the chamber 31 and functions as an anode electrode. Above the stage 33, a shower head 34 is provided so as to face the upper surface of the stage 33. The shower head 34 is formed of a conductive material and is supported by the upper part of the chamber 31 via an insulating member 34a. A power source 35 for supplying high-frequency power for plasma generation is connected to the shower head 34. The shower head 34 functions as a cathode electrode with respect to the stage 33.

[0032] The gas supply source 36 supplies a processing gas. The flow controller 37 adjusts the flow rate of the processing gas supplied from the gas supply source 36 and supplies it into the diffusion space 34b of the shower head 34. The processing gas supplied into the diffusion space 34b diffuses in the diffusion space 34b and is supplied in a shower shape into the chamber 31 from a plurality of discharge ports 34c formed on the lower surface of the diffusion space 34b. In the example of FIG. 3, one gas supply source 36 and one flow controller 37 are shown, but in reality, a set of the gas supply source 36 and the flow controller 37 is provided for each type of gas used.

[0033] The processing gas supplied into the chamber 31 through the shower head 34 is plasmaized by the high-frequency power supplied into the chamber 31 from the power source 35. Then, a part of the sacrificial material formed on the substrate W is removed or a sealing film is formed on the substrate W by ions, active species, etc. contained in the plasma. In the present embodiment, the sealing film is, for example, a silicon oxide film. As another example, the sealing film may be another silicon-containing film such as a silicon nitride film.

[0034] [Configuration example of the heating device 40] FIG. 4 is a diagram showing an example of the heating device 40. The heating device 40 includes a chamber 41, an exhaust pipe 42, a supply pipe 43, a stage 44, a lamp house 45, and a lamp 46.

[0035] In the chamber 41, a stage 44 on which the substrate W is placed is provided. A lamp house 45 is provided at a position facing the surface of the stage 44 on which the substrate W is placed. In the lamp house 45, a lamp 46 such as an infrared lamp is arranged.

[0036] A gas supply unit 47 is connected to the side wall of the chamber 41 through the supply pipe 43. The gas supply unit 47 supplies an inert gas such as N2 gas into the chamber 41 through the supply pipe 43. Further, an opening 41a for loading and unloading the substrate W is formed in the side wall of the chamber 41. The opening 41a is opened and closed by a gate valve G.

[0037] At the bottom of the chamber 41, an exhaust device 48 is connected via an exhaust pipe 42. The exhaust device 48 has a pressure regulating valve. The exhaust device 48 exhausts the gas in the chamber 41 and controls the pressure regulating valve so that the pressure in the chamber 41 becomes a predetermined pressure.

[0038] With the substrate W placed on the stage 44 and an inert gas being supplied into the chamber 41 via the supply pipe 43, by lighting the lamp 46, the substrate W can be heated to a predetermined temperature in an atmosphere of the inert gas. In this embodiment, the substrate W is heated to a temperature of, for example, 400 °C or lower.

[0039] [Configuration Example of Plasma Processing Apparatus 50] FIG. 5 is a diagram showing an example of a plasma processing apparatus 50. The plasma processing apparatus 50 includes a chamber 501 and a microwave output device 504.

[0040] The chamber 501 is formed in a substantially cylindrical shape, for example, by aluminum whose surface is anodized, and provides a substantially cylindrical processing space S inside. The chamber 501 is grounded for safety. Further, the chamber 501 has a side wall 501a and a bottom wall 501b. The central axis of the side wall 501a is defined as the axis Z. The bottom wall 501b is provided on the lower end side of the side wall 501a. An exhaust port 501h for exhaust is provided in the bottom wall 501b. Further, an opening 501c for carrying the substrate W in and out is formed in the side wall 501a. The opening 501c is opened and closed by a gate valve G. Further, the upper end portion of the side wall 501a is open.

[0041] A dielectric window 507 is provided at the upper end portion of the side wall 501a, and the opening at the upper end portion of the side wall 501a is closed from above by the dielectric window 507. The lower surface of the dielectric window 507 faces the processing space S. An O-ring 506 is arranged between the dielectric window 507 and the upper end portion of the side wall 501a.

[0042] Inside the chamber 501, a stage 502 is provided. The stage 502 is provided so as to face the dielectric window 507 in the direction of the axis Z. The space between the stage 502 and the dielectric window 507 is the processing space S. A substrate W is placed on the stage 502.

[0043] The stage 502 has a base 502a and an electrostatic chuck 502c. The base 502a is formed in a substantially disk shape from a conductive material such as aluminum, for example. The base 502a is disposed in the chamber 501 such that the central axis of the base 502a substantially coincides with the axis Z.

[0044] The base 502a is formed of an insulating material and is supported by a cylindrical support portion 520 that extends in a direction along the axis Z. A conductive cylindrical support portion 521 is provided on the outer periphery of the cylindrical support portion 520. The cylindrical support portion 521 extends from the bottom wall 501b of the chamber 501 toward the dielectric window 507 along the outer periphery of the cylindrical support portion 520. An annular exhaust passage 522 is formed between the cylindrical support portion 521 and the side wall 501a.

[0045] An annular baffle plate 523 having a plurality of through holes formed in the thickness direction is provided above the exhaust passage 522. The exhaust port 501h described above is provided below the baffle plate 523. An exhaust device 531 having a vacuum pump such as a turbo molecular pump and an automatic pressure control valve, etc. is connected to the exhaust port 501h via an exhaust pipe 530. The exhaust device 531 can reduce the pressure of the processing space S to a predetermined degree of vacuum.

[0046] The base 502a also functions as a high-frequency electrode. An RF power supply 540 that outputs an RF signal for an RF bias is electrically connected to the base 502a via a feed rod 542 and a matching unit 541. The RF power supply 540 supplies bias power at a predetermined frequency (for example, 13.56 MHz) suitable for controlling the energy of ions drawn into the substrate W to the base 502a via the matching unit 541 and the feed rod 542.

[0047] The matching unit 541 houses a matcher for matching between the impedance on the RF power supply 540 side and the impedance on the load side mainly including the electrode, plasma, and chamber 501. The matcher includes a blocking capacitor for self-bias generation.

[0048] An electrostatic chuck 502c is provided on the upper surface of the base 502a. The electrostatic chuck 502c adsorbs and holds the substrate W by electrostatic force. The electrostatic chuck 502c has a substantially disk-shaped outer shape, and a heater 502d is embedded therein. The heater 502d is electrically connected to a heater power supply 550 via wiring 552 and a switch 551. The heater 502d heats the substrate W placed on the electrostatic chuck 502c with the power supplied from the heater power supply 550. An edge ring 502b is provided on the base 502a. The edge ring 502b is arranged to surround the substrate W and the electrostatic chuck 502c. The edge ring 502b is sometimes called a focus ring.

[0049] A flow path 502g is provided inside the base 502a. A refrigerant is supplied to the flow path 502g from a chiller unit (not shown) via a pipe 560. The refrigerant supplied into the flow path 502g is returned to the chiller unit via a pipe 561. By circulating the refrigerant whose temperature is controlled by the chiller unit in the flow path 502g of the base 502a, the temperature of the base 502a is controlled. The temperature of the substrate W on the electrostatic chuck 502c is controlled by the refrigerant flowing inside the base 502a and the heater 502d inside the electrostatic chuck 502c.

[0050] Also, the stage 502 is provided with a pipe 562 for supplying a heat transfer gas such as helium gas between the electrostatic chuck 502c and the substrate W.

[0051] The microwave output device 504 outputs microwaves for exciting the processing gas supplied into the chamber 501. The microwave output device 504 generates microwaves having a frequency of, for example, 2.4 GHz.

[0052] The output section of the microwave output device 504 is connected to one end of the waveguide 508. The other end of the waveguide 508 is connected to the mode converter 509. The mode converter 509 converts the mode of the microwave output from the waveguide 508 and supplies the microwave after mode conversion to the antenna 505 via the coaxial waveguide 510.

[0053] The coaxial waveguide 510 includes an outer conductor 510a and an inner conductor 510b. The outer conductor 510a and the inner conductor 510b have a substantially cylindrical shape and are arranged above the antenna 505 such that the central axis of the outer conductor 510a and the inner conductor 510b substantially coincides with the axis Z.

[0054] The antenna 505 includes a cooling jacket 505a, a dielectric plate 505b, and a slot plate 505c. The slot plate 505c is formed in a substantially disc shape from a conductive metal. The slot plate 505c is provided on the upper surface of the dielectric window 507 such that the central axis of the slot plate 505c coincides with the axis Z. A plurality of slot holes are formed in the slot plate 505c. The plurality of slot holes are arranged in pairs around the central axis of the slot plate 505c.

[0055] The dielectric plate 505b is formed in a substantially disc shape from a dielectric material such as quartz. The dielectric plate 505b is arranged on the slot plate 505c such that the central axis of the dielectric plate 505b substantially coincides with the axis Z. The cooling jacket 505a is provided on the dielectric plate 505b.

[0056] The cooling jacket 505a is formed of a material having conductivity on its surface, and a flow path 505e is formed inside. A refrigerant is supplied into the flow path 505e from a chiller unit (not shown). The lower end of the outer conductor 510a is electrically connected to the upper surface of the cooling jacket 505a. Also, the lower end of the inner conductor 510b is electrically connected to the slot plate 505c through an opening formed in the central portion of the cooling jacket 505a and the dielectric plate 505b.

[0057] The microwave propagated within the coaxial waveguide 510 propagates through the dielectric plate 505b and then propagates from the plurality of slot holes of the slot plate 505c to the dielectric window 507. The microwave propagated to the dielectric window 507 is radiated into the processing space S from the lower surface of the dielectric window 507.

[0058] A gas tube 511 is provided inside the inner conductor 510b of the coaxial waveguide 510. A through hole 505d through which the gas tube 511 can pass is formed in the central portion of the slot plate 505c. The gas tube 511 extends through the inside of the inner conductor 510b and is connected to the gas supply unit 512.

[0059] The gas supply unit 512 supplies a processing gas for processing the substrate W to the gas tube 511. The gas supply unit 512 includes a gas supply source 512a, a valve 512b, and a flow controller 512c. The gas supply source 512a is a supply source of the processing gas. The valve 512b controls the supply and stop of the processing gas from the gas supply source 512a. The flow controller 512c is, for example, a mass flow controller or the like, and controls the flow rate of the processing gas from the gas supply source 512a.

[0060] An injector 513 is provided inside the dielectric window 507. The injector 513 injects the processing gas supplied through the gas tube 511 into the processing space S through the through hole 507h formed in the dielectric window 507. The processing gas injected into the processing space S is excited by the microwave radiated into the processing space S through the dielectric window 507. As a result, the processing gas is plasmaized in the processing space S, and ions, radicals, etc. contained in the plasma are radiated onto the substrate W. Thereby, the residue remaining in the concave portion of the substrate W after heating the substrate W can be removed.

[0061] [Method for manufacturing semiconductor device] FIG. 6 is a flowchart showing an example of a method for manufacturing a semiconductor device. The manufacturing method illustrated in FIG. 6 is realized by the control device 15 controlling each part of the manufacturing system 10. Hereinafter, an example of a method for manufacturing a semiconductor device will be described with reference to FIGS. 7 to 12.

[0062] First, the substrate W is carried into the chamber 21 of the film forming apparatus 20 (step S100). In step S100, for example, as shown in FIG. 7, the substrate W having the recess 60 formed therein is carried into the chamber 21 of the film forming apparatus 20.

[0063] Next, a sacrificial material is embedded in the recess 60 (step S101). Step S101 is an example of step a). In step S101, a first monomer and a second monomer are supplied into the chamber 21, and a vapor phase polymerization reaction of the first monomer and the second monomer is caused to embed the sacrificial material in the recess 60 of the substrate W. In the present embodiment, the first monomer is, for example, isocyanate, the second monomer is, for example, amine, and the sacrificial material has a polyurea bond. As a result, for example, as shown in FIG. 8, the sacrificial material 61 is embedded in the recess 60.

[0064] In step S101, the sacrificial material 61 is embedded in the recess of the substrate W under, for example, the following processing conditions. Pressure in chamber 21: 0.5 to 20 Torr (66.7 to 2666 Pa) Flow rate of isocyanate vapor: 1 to 20 sccm (0.0017 to 0.034 Pa·m 3 / s) Flow rate of amine vapor: 1 to 20 sccm (0.0017 to 0.034 Pa·m 3 / s) Temperature of substrate W: 40 to 150 ° C

[0065] Next, the substrate W is transferred from the film forming apparatus 20 to the plasma processing apparatus 30 (step S102). In step S102, the substrate W is carried out from the chamber 21 of the film forming apparatus 20 by the transfer robot 110 in the VTM11 and carried into the chamber 31 of the plasma processing apparatus 30.

[0066] Next, unnecessary sacrificial material 61 on the substrate W is removed (step S103). In step S103, plasma is generated from the processing gas in the chamber 31. The processing gas is, for example, a mixed gas of hydrogen gas and nitrogen gas. Then, by the generated plasma, for example, as shown in FIG. 9, the unnecessary sacrificial material 61 formed around the recess 60 is removed. In step S103, the unnecessary sacrificial material 61 is removed by the plasma processing apparatus 30 under the following processing conditions, for example. Pressure in chamber 31: 0.05 - 1.0 Torr (6.67 - 133 Pa) Processing gas: H2 / N2 = 100 - 300 sccm / 100 - 300 sccm (0.17 - 0.51 Pa·m 3 / s / 0.17 - 0.51 Pa·m 3 / s) High-frequency power: 100 - 400 W Temperature of substrate W: 40 - 200 °C

[0067] Next, a sealing film is formed on the recess 60 filled with the sacrificial material 61 (step S104). Step S104 is an example of step b). In step S104, plasma is generated from a processing gas such as organic aminosilane in the chamber 31. Then, by the generated plasma, for example, as shown in FIG. 10, a sealing film 62 is formed on the recess 60 filled with the sacrificial material 61. In the present embodiment, the sealing film 62 is, for example, a silicon oxide film. Note that the sealing film 62 may be another silicon-containing film such as a silicon nitride film. In step S104, the sealing film 62 is formed by the plasma processing apparatus 30 under the following processing conditions, for example. Pressure in chamber 31: 0.1 - 10 Torr (13.3~1333 Pa) Processing gas: organic aminosilane = 10~50 sccm (0.017~0.085 Pa·m 3 / s) High-frequency power: 50~200 W Temperature of substrate W: 20~200 °C

[0068] Next, the substrate W is transferred from the plasma processing apparatus 30 to the heating apparatus 40 (step S105). In step S105, the substrate W is carried out of the chamber 31 of the plasma processing apparatus 30 by the transfer robot 110 in the VTM11 and carried into the chamber 41 of the heating apparatus 40.

[0069] Next, the substrate W is heated (step S106). Step S106 is an example of step d). In step S106, the sacrificial material 61 is thermally decomposed by heating the substrate W to a temperature of, for example, 400 °C or lower, and the sacrificial material 61 is desorbed through the sealing film 62. As a result, an air gap 63 is formed between the sealing film 62 and the recess 60, as shown in FIG. 11, for example. In step S106, the substrate W is heated under the following processing conditions, for example. Pressure in chamber 41: 0.5~20 Torr (66.7~2666 Pa) Gas supplied into chamber 41: N2 = 200~2000 sccm (0.34~3.4 Pa·m 3 / s) Temperature of substrate W: 350~400 °C

[0070] Next, the substrate W is transferred from the heating apparatus 40 to the plasma processing apparatus 50 (step S107). In step S107, the substrate W is carried out of the chamber 41 of the heating apparatus 40 by the transfer robot 110 in the VTM11 and carried into the chamber 501 of the plasma processing apparatus 50.

[0071] Next, plasma treatment is performed (step S108). Step S108 is an example of step c). In step S108, plasma is generated from the processing gas inside the chamber 501. In the present embodiment, the processing gas is, for example, oxygen gas. As another example, the processing gas may be a noble gas such as argon gas, or may be hydrogen gas, nitrogen gas, or the like.

[0072] In step S108, the processing gas is plasmaized outside the recess 60. Then, active species, ions, etc. contained in the plasma are supplied into the recess 60 through the sealing film 62. In step S108, for example, under the following processing conditions, plasma treatment is executed by the plasma treatment apparatus 50. Pressure inside the chamber 501: 0.5 to 1 Torr (66.7 to 133 Pa) Processing gas: H2 = 10 to 50 sccm (0.017 to 0.085 Pa·m 3 / s) Power of microwave: 100 to 200 W Temperature of the substrate W: 20 to 400 °C

[0073] Next, the substrate W is carried out of the plasma treatment apparatus 50 (step S109). Then, the manufacturing method of the semiconductor device shown in this flowchart ends.

[0074] Here, depending on the heat resistance temperature of the substrate W and other structures formed on the substrate W, there may be cases where the substrate W cannot be heated to too high a temperature, or cases where heating cannot be performed for too long a time. In such cases, after removing the sacrificial material 61 by heating the substrate W, for example, as shown in FIG. 11, there may be cases where residues 64 remain inside the recess 60. When residues 64 remain inside the recess 60, the volume of the air gap 63 may become smaller than the desired volume. Also, if the amount of residues 64 varies among the air gaps 63, variations in volume may occur among the plurality of air gaps 63.

[0075] Therefore, in the present embodiment, after removing the sacrificial material 61 by heating the substrate W, in step S108, the processing gas is plasmaized outside the recess 60, and active species, ions, etc. contained in the plasma are supplied into the recess 60 through the sealing film 62. The residue 64 remaining in the recess 60 is decomposed by the active species, ions, etc. supplied into the recess 60 and desorbed through the sealing film 62. As a result, for example, as shown in FIG. 12, the residue 64 in the recess 60 can be reduced. Therefore, the volume of the air gap 63 can be made closer to the desired volume, and the variation in volume between the plurality of air gaps 63 can be reduced.

[0076] [Relationship between heating temperature and residue] FIG. 13 is a diagram showing an example of the relationship between the heating temperature and the amount of residue. In the example of FIG. 13, the ratio of the amount of residue 64 after heating to the amount of the sacrificial material 61 before heating is shown. Further, in the example of FIG. 13, the thickness of the sealing film 62 is 2.0 nm.

[0077] For example, as shown in FIG. 13, increasing the temperature at which the substrate W is heated can reduce the amount of residue 64. However, if the heating temperature cannot be increased so much, the amount of residue increases. For example, when the heating temperature is 400 ° C, about 6.5% of the sacrificial material 61 remains in the recess 60 as the residue 64.

[0078] [Relationship between type of plasma and residue] FIG. 14 is a diagram showing an example of the relationship between the type of plasma and the amount of residue. In the example of FIG. 14, the ratio of the amount of residue 64 to the amount of the sacrificial material 61 before heating is shown.

[0079] When the thickness of the sealing film 62 is 2.0 nm, when the sacrificial material 61 was removed only by heating at 400 ° C, about 6.5% remained in the recess 60 as the residue 64. On the other hand, when oxygen gas was plasmaized after heating at 400 ° C (oxygen plasma), the residue 64 decreased to about 2.4%. Also, when argon gas was plasmaized after heating at 400 ° C (argon plasma), the residue 64 decreased to about 2.8%.

[0080] Also, when the thickness of the sealing film 62 was 2.4 nm and the sacrificial material 61 was removed only by heating at 400°C, about 37.2% remained in the recess 60 as the residue 64. On the other hand, when oxygen gas was plasmaized after heating at 400°C (oxygen plasma), the residue 64 decreased to about 6.9%. Also, when argon gas was plasmaized after heating at 400°C (argon plasma), the residue 64 decreased to about 15.0%.

[0081] As is clear from the results illustrated in FIG. 14, by generating a plasma of oxygen gas or argon gas after heating and supplying active species contained in the plasma into the recess 60 through the sealing film 62, the residue 64 can be reduced as compared with the case of only heating. Also, from the viewpoint of the reduction rate of the residue 64, the reduction rate of the residue 64 is greater when oxygen gas is plasmaized than when argon gas is plasmaized. In the example of FIG. 14, argon gas was plasmaized, but it is considered that the same effect can be obtained when other rare gases other than argon gas are used.

[0082] The embodiments have been described above. As described above, the method for manufacturing a semiconductor device according to the present embodiment includes step a), step b), and step c). In step a), a sacrificial material (sacrificial material 61) is embedded in a recess (recess 60) formed in a substrate (substrate W). In step b), the recess in which the sacrificial material is embedded is covered with a sealing film (sealing film 62). In step c), a processing gas is plasmaized outside the recess, and active species contained in the plasma are supplied to the sacrificial material through the sealing film, whereby the sacrificial material in the recess is decomposed and the sacrificial material in the recess is removed through the sealing film. Thereby, the residue in the air gap can be reduced.

[0083] In the above-described embodiment, the sacrificial material is a thermally decomposable organic material. Further, the method for manufacturing a semiconductor device in the above-described embodiment further includes step d). Step d) is a step executed between step b) and step c), and by heating the substrate to a temperature at which the sacrificial material decomposes, at least a part of the sacrificial material in the recess is removed through the sealing film. Thereby, the sacrificial material can be efficiently removed.

[0084] In the above-described embodiment, the sacrificial material is a thermally decomposable organic material containing a urea bond. In step a), gases of a first monomer and a second monomer are supplied into the chamber into which the substrate has been carried in, and the sacrificial material is embedded in the recess by vapor deposition polymerization of the first monomer and the second monomer. Further, the first monomer is isocyanate, and the second monomer is amine. Thereby, the sacrificial material can be decomposed by heating, and the sacrificial material can be efficiently removed.

[0085] In the above-described embodiment, the temperature when heating the substrate is 400°C or lower. Thereby, damage to the substrate W and other structures formed on the substrate W due to heat can be suppressed.

[0086] In the above-described embodiment, the processing gas used in step c) contains at least one of hydrogen gas, nitrogen gas, oxygen gas, and rare gas. Thereby, residues in the air gap can be reduced.

[0087] In the above-described embodiment, the sealing film is a silicon oxide film or a silicon nitride film. Thereby, the sacrificial material in the recess can be efficiently removed.

[0088] In the above-described embodiment, in step c), the processing gas is made into plasma by microwaves. Thereby, the processing gas can be efficiently made into plasma.

[0089] In addition, the semiconductor device manufacturing system (manufacturing system 10) in the above-described embodiment includes a first processing device (film forming device 20), a second processing device (plasma processing device 30), a third processing device (plasma processing device 50), and a control device (control device 15) that controls the first processing device, the second processing device, and the third processing device. The control device executes steps a), b), and c). In step a), a sacrificial material is embedded in the recess using the first processing device. In step b), the recess in which the sacrificial material is embedded is covered with a sealing film using the second processing device. In step c), using the third processing device, a processing gas is plasmaized outside the recess, and active species contained in the plasma are supplied to the sacrificial material through the sealing film, thereby decomposing the sacrificial material in the recess and removing the sacrificial material in the recess through the sealing film. As a result, residues in the air gap can be reduced.

[0090] [Others] Note that the technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist.

[0091] For example, in the above-described embodiment, after the sealing film 62 is formed on the recess 60 in which the sacrificial material 61 is embedded, the substrate W is heated, and after the sacrificial material 61 in the recess 60 is removed to some extent, the substrate W is irradiated with plasma. However, the disclosed technology is not limited to this. For example, as another form, after the sealing film 62 is formed on the recess 60 in which the sacrificial material 61 is embedded, the substrate W may be irradiated with plasma without heating the substrate W. As a result, the heating device 40 becomes unnecessary, and the manufacturing system 10 can be miniaturized.

[0092] In the above-described embodiment, after the sealing film 62 is formed on the recess 60 in which the sacrificial material 61 is embedded, the substrate W is heated, and after the sacrificial material 61 in the recess 60 is removed to some extent, the substrate W is irradiated with plasma. However, the disclosed technology is not limited to this. For example, as another form, after the sealing film 62 is formed on the recess 60 in which the sacrificial material 61 is embedded, the substrate W may be irradiated with plasma while heating the substrate W to a temperature of 400°C or lower. In this case, the plasma irradiation of the substrate W is performed by the plasma processing apparatus 50, and the substrate W is heated by the heater 502d embedded in the electrostatic chuck 502c of the plasma processing apparatus 50, for example. Thereby, the sacrificial material 61 in the recess 60 can be removed in a shorter time. In addition, since the heating device 40 is unnecessary, the manufacturing system 10 can be downsized.

[0093] Also, in the above-described embodiment, when the substrate W is heated after the sealing film 62 is formed on the recess 60 in which the sacrificial material 61 is embedded and then the substrate W is irradiated with plasma, the substrate W may also be heated to a temperature of 400°C or lower.

[0094] In the above-described embodiment, oxygen gas is plasmaized to remove the residue 64, and active species, ions, etc. contained in the plasma are supplied into the recess 60 through the sealing film 62. However, the disclosed technology is not limited to this. For example, when forming an air gap between metal wirings, if the residue in the recess between the metal wirings is removed with plasma using oxygen gas, the metal wirings may be oxidized by active species, ions, etc. derived from oxygen, and the resistance value of the metal wirings may increase. Therefore, when forming an air gap between metal wirings, it is preferable to plasmaize a gas that does not contain oxygen, such as hydrogen gas, nitrogen gas, and noble gas. Thereby, while suppressing an increase in the resistance value of the metal wirings, the residue remaining in the air gap between the metal wirings can be removed.

[0095] In the above-described embodiment, an organic material that can be thermally decomposed is used as the sacrificial material 61. However, the disclosed technology is not limited to this. For example, in other forms, silicon-containing substances such as amorphous silicon or carbon-containing substances such as amorphous carbon may be used as the sacrificial material 61. When such materials are used as the sacrificial material 61, the heating device 40 is unnecessary, and step S106 is also unnecessary. Further, when a silicon-containing substance is used as the sacrificial material 61, in the plasma treatment of step S108, a gas containing, for example, oxygen gas is used as the treatment gas. Further, when a carbon-containing substance is used as the sacrificial material 61, in the plasma treatment of step S108, oxygen gas, for example, is used as the treatment gas.

[0096] Also, in the above-described embodiment, in steps S103 and S104, capacitively coupled plasma is used as the plasma source, and in step S108, microwave plasma is used as the plasma source. However, the disclosed technology is not limited to this. As another form, in steps S103 and S104, microwave plasma may be used as the plasma source. Further, in step S108, capacitively coupled plasma may be used as the plasma source. Alternatively, in steps S103, S104, and S108, other plasma sources such as inductively coupled plasma or magnetron plasma may be used as the plasma source.

[0097] In the above-described embodiment, a sacrificial material 61 of a thermally decomposable polymer having a urea bond (-NH-CO-NH-) is formed on the surface of the substrate W using isocyanate as the first monomer and amine as the second monomer. However, the disclosed technology is not limited to this. For example, a sacrificial material 61 of a thermally decomposable polymer having a 2-aminoethanol bond (-NH-CH2-CH(OH)-) may be formed on the surface of the substrate W using epoxide as the first monomer and amine as the second monomer. Alternatively, a sacrificial material 61 of a thermally decomposable polymer having a urethane bond (-NH-CO-O-) may be formed on the surface of the substrate W using isocyanate as the first monomer and alcohol as the second monomer. Alternatively, a sacrificial material 61 of a thermally decomposable polymer having an amide bond (-NH-CO-) may be formed on the surface of the substrate W using acyl halide as the first monomer and amine as the second monomer. Alternatively, a sacrificial material 61 of a thermally decomposable polymer having an imide bond (-CO-N(-)-CO-) may be formed on the surface of the substrate W using carboxylic anhydride as the first monomer and amine as the second monomer.

[0098] It should be considered that all aspects of the embodiments disclosed this time are illustrative and not restrictive. In fact, the above-described embodiments can be embodied in various forms. Also, the above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and spirit of the appended claims.

[0099] Regarding the above embodiments, the following additional remarks are further disclosed.

[0100] (Supplementary Note 1) a) A step of embedding a sacrificial material in a recess formed in a substrate; b) A step of covering the recess in which the sacrificial material is embedded with a sealing film; c) A step of decomposing the sacrificial material in the recess by forming the treatment gas into plasma outside the recess and supplying the active species contained in the plasma to the sacrificial material through the sealing film, and removing the sacrificial material in the recess through the sealing film A method for manufacturing a semiconductor device including (Appendix 2) The sacrificial material is a thermally decomposable organic material, The method for manufacturing the semiconductor device is d) A step executed between the step b) and the step c), wherein at least a part of the sacrificial material in the recess is removed through the sealing film by heating the substrate to a temperature at which the sacrificial material decomposes The method for manufacturing a semiconductor device according to Appendix 1, further including (Appendix 3) The sacrificial material is a thermally decomposable organic material, In the step c), the substrate is heated to a temperature at which the sacrificial material decomposes. The method for manufacturing a semiconductor device according to Appendix 1 or 2 (Appendix 4) The sacrificial material is a thermally decomposable organic material, In the step a), gases of a first monomer and a second monomer are supplied into a chamber into which a substrate is carried in, and the sacrificial material is embedded in the recess by vapor deposition polymerization of the first monomer and the second monomer, The first monomer is isocyanate, The second monomer is amine, The sacrificial material contains a urea bond. The method for manufacturing a semiconductor device according to Appendix 2 or 3 (Appendix 5) The temperature when heating the substrate is 400 °C or lower. The method for manufacturing a semiconductor device according to any one of Appendices 2 to 4 (Appendix 6) The processing gas contains at least one of hydrogen gas, nitrogen gas, oxygen gas, and noble gas. The method for manufacturing a semiconductor device according to any one of Appendices 1 to 5 (Appendix 7) The processing gas contains at least one of hydrogen gas, nitrogen gas, and noble gas. The method for manufacturing a semiconductor device according to Appendix 6 (Appendix 8) The method for manufacturing a semiconductor device according to any one of Appendices 1 to 7, wherein the sealing film is a silicon oxide film or a silicon nitride film. (Appendix 9) The method for manufacturing a semiconductor device according to any one of Appendices 1 to 9, wherein in the step c), the processing gas is converted into plasma by microwaves. (Appendix 10) A first processing device, A second processing device, A third processing device, A control device for controlling the first processing device, the second processing device, and the third processing device and comprising: The control device a) a step of embedding a sacrificial material into the recess using the first processing device; b) a step of covering the recess in which the sacrificial material is embedded with a sealing film using the second processing device; c) a step of decomposing the sacrificial material in the recess and removing the sacrificial material in the recess through the sealing film by converting a processing gas into plasma outside the recess using the third processing device and supplying active species contained in the plasma to the sacrificial material through the sealing film A semiconductor device manufacturing system that executes the above steps.

Explanation of Reference Numerals

[0101] G Gate valve W Substrate 10 Manufacturing system 11 VTM 110 Transfer robot 12 LLM 13 EFEM 130 Transfer robot 14 Load port 15 Control device 20 Film forming device 30 Plasma processing device 40 Heating device 50 Plasma processing device 60 Recess 61 Sacrificial material 62 Sealing film 63 Air gap 64 Residue

Claims

1. a) a step of embedding a sacrificial material in a recess formed in a substrate; b) a step of covering the recess in which the sacrificial material is embedded with a sealing film; c) a step of decomposing the sacrificial material in the recess by plasmaizing a processing gas outside the recess and supplying active species contained in the plasma to the sacrificial material through the sealing film, and removing the sacrificial material in the recess through the sealing film A method for manufacturing a semiconductor device including the above.

2. The sacrificial material is an organic material that can be thermally decomposed, The method for manufacturing the semiconductor device d) a step performed between the step b) and the step c), of removing at least a part of the sacrificial material in the recess through the sealing film by heating the substrate to a temperature at which the sacrificial material thermally decomposes The method for manufacturing a semiconductor device according to claim 1, further including the above.

3. The sacrificial material is an organic material that can be thermally decomposed, In the step c), the substrate is heated to a temperature at which the sacrificial material thermally decomposes. The method for manufacturing a semiconductor device according to claim 1 or 2.

4. The sacrificial material is an organic material that can be thermally decomposed, In the step a), a gas of a first monomer and a second monomer is supplied into a chamber into which the substrate is carried in, and the sacrificial material is embedded in the recess by vapor deposition polymerization of the first monomer and the second monomer. The first monomer is isocyanate, The second monomer is amine, The method for manufacturing a semiconductor device according to claim 2, wherein the sacrificial material contains a urea bond.

5. The temperature when heating the substrate is 400 ° C or lower. The method for manufacturing a semiconductor device according to claim 2.

6. The processing gas contains at least any one of hydrogen gas, nitrogen gas, oxygen gas, and rare gas. The method for manufacturing a semiconductor device according to claim 1.

7. The processing gas contains at least any one of hydrogen gas, nitrogen gas, and rare gas. The method for manufacturing a semiconductor device according to claim 6.

8. The sealing film is a silicon oxide film or a silicon nitride film. The method for manufacturing a semiconductor device according to claim 1.

9. In the step c), the processing gas is plasmaized by microwaves. The method for manufacturing a semiconductor device according to claim 1.

10. A first processing device, A second processing device, A third processing device, a control device that controls the first processing device, the second processing device, and the third processing device; and comprises: the control device: a) using the first processing device, a step of embedding a sacrificial material into a recess formed in a substrate; b) using the second processing device, a step of covering the recess filled with the sacrificial material with a sealing film; c) using the third processing device, a step of decomposing the sacrificial material in the recess by plasmaizing a processing gas outside the recess and supplying active species contained in the plasma to the sacrificial material through the sealing film, and removing the sacrificial material in the recess through the sealing film A semiconductor device manufacturing system that performs the above steps.

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