Substrate processing method, substrate processing apparatus, and substrate processing system

Abstract

To provide a technique that can generate a large stress on a second surface of a substrate opposite to a first surface on which a device is formed.SOLUTION: A substrate processing method includes the steps of preparing a substrate having a first surface on which a device is formed, and depositing a silicon-containing film on a second surface opposite the first surface of the substrate using a high-order silane gas as a deposition gas at a temperature at which the high-order silane gas is liquefied.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a substrate processing apparatus, and a substrate processing system.

Background Art

[0002] Patent Document 1 describes a technique for applying stress to a substrate by forming a dummy film having compressive stress, such as a SiO2 film or a SiN film, on the back surface of the substrate by ALD or CVD.

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 technique capable of generating a large stress on a second surface opposite to a first surface on which a device of a substrate is formed.

Means for Solving the Problems

[0005] A substrate processing method according to an aspect of the present disclosure includes a step of preparing a substrate having a first surface on which a device is formed, and a step of supplying a higher-order silane gas as a film-forming gas to a second surface opposite to the first surface of the substrate and forming a silicon-containing film at a temperature at which the higher-order silane gas liquefies.

Effects of the Invention

[0006] According to the present disclosure, a technique capable of generating a large stress on a second surface opposite to a first surface on which a device of a substrate is formed is provided.

Brief Description of the Drawings

[0007]

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Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments will be specifically described with reference to the accompanying drawings.

[0009] <First Embodiment> [Substrate Processing Method] FIG. 1 is a flowchart showing a substrate processing method according to a first embodiment, and FIG. 2 is a process cross-sectional view thereof.

[0010] In the present embodiment, first, a substrate 1 having a first surface 2 on which a device is to be formed is prepared (step ST1, FIG. 2(a)). Next, a higher-order silane gas as a film-forming gas is supplied to the second surface 3 on the side opposite to the first surface 2 of the substrate 1, and a silicon-containing film 4 is formed at a temperature at which the higher-order silane gas liquefies (step ST2, FIG. 2(b)).

[0011] In step ST1, the substrate 1 is not particularly limited, but a typical example is a semiconductor substrate (wafer). The device may or may not actually be formed on the first surface 2 of the substrate, and it may also be in a stage of forming a device.

[0012] In step ST2, a higher-order silane gas is used as a film-forming gas, and a silicon-containing film 4 is formed on the second surface 3 of the substrate 1 at a temperature at which the higher-order silane gas liquefies. The silicon-containing film 4 may be formed over the entire second surface 3, or may be formed on a part of the second surface 3.

[0013] Higher-order silane gas can be liquefied at a realistic temperature of about -30°C. By forming a film at the temperature at which the higher-order silane gas liquefies, a film is formed in a state where low-molecular-weight components remain in the film. Therefore, when energy such as heat or light is applied to the obtained silicon-containing film, a large amount of the components in the film vaporize and aggregate, causing the film to shrink significantly. The shrinkage can generate a large stress on the second surface 3 of the substrate 1. That is, the silicon-containing film 4 formed using higher-order silane gas at the temperature at which the higher-order silane gas liquefies has a high stress generation ability with respect to the substrate.

[0014] The process of step ST2 can be performed, for example, by placing the substrate on the mounting table in the chamber with the second surface facing up, maintaining the substrate at the temperature at which the higher-order silane gas liquefies on the mounting table, introducing the higher-order silane gas into the chamber, and supplying it to the second surface of the substrate in a state excited by plasma. At this time, by flowing a refrigerant through the mounting table, the substrate can be maintained at the temperature at which the higher-order silane gas liquefies, for example, -30°C. The pressure in the chamber at this time may be in the range of 10 Torr or less, for example, 1 Torr.

[0015] By exciting the higher-order silane gas with plasma in this way, the skeleton of the film can be formed by gas-phase polymerization even at a low temperature, and film formation can proceed. Also, by using plasma, a film with high adhesion can be obtained. The plasma is not particularly limited, and various types such as capacitively coupled plasma, inductively coupled plasma, and microwave plasma can be used.

[0016] Higher-order silane includes disilane (Si2H6), trisilane (Si3H8), tetrasilane (Si4H 10 ) etc., and is represented by the general formula Si n H 2n+2 (n is a positive integer of 2 or more). Si2H6, Si3H8, Si4H 10Their boiling points are -14.5°C, 52.8°C, and 108.1°C respectively, all of which are sufficiently higher than the boiling point of monosilane (SiH4) at -112°C and can be stably liquefied at a realistic temperature of about -30°C as described above. As higher-order silanes, those with n of 4 or more can obtain a greater shrinking ability.

[0017] As the gas used for film formation, in addition to higher-order silane gas, H2 gas or a noble gas (e.g., Ar gas) as a plasma-generating gas may also be used. When only higher-order silane gas or higher-order silane with H2 gas added is used as the film-forming gas, the silicon-containing film is a Si-based film and becomes a Si film after the vaporization components in the film are vaporized. An oxygen-containing gas may be further added as the film-forming gas to finally make the silicon-containing film a SiO2-based film that becomes a SiO2 film. By changing the film quality of the silicon-containing film in this way, the shrinking characteristics change, and the ability to generate stress on the second surface of the substrate can be adjusted.

[0018] Since the silicon-containing film 4 has a large stress generation ability, it may be thinner compared to the films formed by conventional CVD or ALD. The film thickness of the silicon-containing film 4 may be appropriately set according to the stress to be generated and may be in the range of 1 to 10,000 nm.

[0019] Actually, tetrasilane was used as the higher-order silane, which is the film-forming gas, the substrate was held at -30°C at which the higher-order silane gas liquefies on the stage in the chamber, and the higher-order silane gas was supplied to the substrate in a state excited by plasma to form a silicon-containing film. Then, the ability to generate stress on the second surface of the substrate was investigated.

[0020] Specifically, first, after forming the silicon-containing film, the substrate on which the silicon-containing film was formed on the stage was annealed at various temperatures, and the desorbed gas at that time was subjected to temperature-programmed desorption gas analysis (Thermal As a result of analysis by thermal desorption spectroscopy (TDS), it was confirmed that H2 gas and silane gases such as SiH4, Si2H6, and Si3H8 were desorbed. Similarly, after annealing the substrate at various temperatures and confirming the film structure change by Fourier transform infrared (FT-IR), as the annealing temperature increased, the intensity of SiH x (SiH, SiH2, SiH3(SiH2) n etc.) was confirmed to have decreased. From these results, it was confirmed that the shrinkage of the silicon-containing film formed according to this embodiment was caused by the desorption of H2 gas and silane gases.

[0021] Next, the stress generated on the second surface of the substrate due to the shrinkage of the silicon-containing film formed according to this embodiment was confirmed. Here, as shown in FIG. 3, based on a sample in which thermal oxide films 203 and 204 were formed with a thickness of 100 nm on both the first surface 201 and the second surface 202 of the Si substrate 200, as shown in FIG. 4, a sample was prepared in which a silicon-containing film 205 was formed with a thickness of 50 nm on the thermal oxide film 204 on the second surface 202 side of the Si substrate 200. The thermal oxide film was formed to distinguish it from the Si substrate since the silicon-containing film is a Si-based film.

[0022] This sample was annealed to grasp the stress generated on the second surface 202 of the substrate 200 due to the shrinkage of the silicon-containing film 205. The stress was measured by cross-sectional Raman measurement (Raman spectroscopy). The stress generated in the substrate due to the shrinkage of the silicon-containing film can be calculated based on the shift (Raman shift) from the peak of the Si crystal (crystal without stress) in the spectrum of the Raman scattered light (Raman spectrum), which is 520 (cm -1 ). Specifically, ν: Raman shift (cm -1) When Σ is the stress (MPa), since there is a relationship shown in the following equation (1), based on this equation (1) and the Raman shift, the stress applied to the second surface of the substrate due to the shrinkage of the silicon-containing film can be calculated. ν = -1.93×10 -3 Σ ···(1)

[0023] Figure 5 is a diagram showing the relationship between the annealing temperature and the Raman shift when annealing is performed on the above sample. The annealing time was about 1 hour at each temperature. The Raman shift on the vertical axis is based on the peak of silicon at 520 (cm -1 ) which is set to 0, with minus indicating the tensile direction and plus indicating the compressive direction. Note that the substrate stress is relaxed by the thermal oxide film, but here it is corrected to exclude the influence of the thermal oxide film. In Figure 5, A is the value of the Raman shift in the initial state where no silicon-containing film is formed for comparison, and the others are the values of the Raman shift in the state after annealing at a predetermined temperature after forming the silicon-containing film.

[0024] As shown in Figure 5, in A which is the initial state where no silicon-containing film is formed, the Raman shift of the substrate is -0.4 cm -1 . That is, in the initial state, as shown in Figure 6, a tensile stress 210 of about 200 MPa is generated on the second surface 202 of the substrate 200. After forming the silicon-containing film 205, the Raman shift becomes slightly larger at -0.5 cm -1 , and when the annealing temperature is less than 100 °C, the Raman shift remains negative (B and C in Figure 5). That is, as shown in Figure 7, the tensile stress 210 remains generated on the second surface 202 of the substrate 200. However, the Raman shift changes significantly between the annealing temperatures of 100 °C and 200 °C, and at 200 °C, the Raman shift becomes positive (D in Figure 5). That is, as shown in Figure 8, the stress generated on the second surface 202 of the substrate 200 changes from the tensile stress 210 to the compressive stress 220. When the annealing temperature is 200 °C or higher, the Raman shift does not change significantly, but at 400 °C, the Raman shift is +0.5 cm -1It has reached the above maximum value (E in FIG. 5). From this, by annealing the silicon-containing film at a temperature of about 100 to 400 °C, particularly about 100 to 200 °C, the Raman shift is approximately -0.5 cm -1 to +0.5 cm -1 and the change amount is 1.0 cm -1 or so. It was confirmed that when the stress was calculated from the change amount of this Raman shift by equation (1), it was 500 MPa or more, and it was confirmed that extremely large stress could be generated with a relatively thin film thickness of 50 nm.

[0025] That is, it was confirmed that the silicon-containing film formed at the temperature at which higher-order silane gas liquefies on the substrate using higher-order silane gas as the film-forming gas according to the present embodiment is a film that can generate extremely large stress on the substrate.

[0026] Conventionally, in the process of forming a device on one side (the first surface) of a wafer as a substrate, in order to repeat film formation and pattern formation by etching, it has been known that stress is applied to the substrate by the film. In order to relieve the influence of such stress, it is effective to thicken the wafer as the substrate, but it is difficult to cope with technologies that require thinning the wafer, such as the wafer bonding technology currently being carried out. In addition, pattern shift, misalignment during exposure, etc. occur due to the presence of a large number of films with stress. For this reason, a technique has been proposed in Patent Document 1 described above, in which a film is formed on the second surface opposite to the first surface of the substrate to generate stress on the substrate and relieve the stress of the substrate.

[0027] However, as described in Patent Document 1 above, the film formed on the second surface is formed by general CVD or ALD, and cannot generate so much stress on the substrate, and it is necessary to cope by increasing the film thickness. In addition, when forming a film by CVD or ALD, the compressive stress generated on the substrate can be increased slightly by forming the film at a high temperature, but the effect is limited, and film formation at a high temperature is generally limited due to the influence on the device.

[0028] In contrast, in this embodiment, a higher-order silane gas is used as the film-forming gas, and by forming a film on the second surface of the substrate at a temperature at which the higher-order silane gas liquefies, a silicon-containing film with high shrinkage ability can be obtained. This film can shrink significantly by annealing or the like, and can apply a large stress to the substrate. Therefore, it is possible to apply a desired stress to the substrate without thickening the film like a film formed by general CVD or ALD. Also, since the film is formed at a low temperature, there are no disadvantages caused by high-temperature film formation.

[0029] [Substrate processing apparatus] FIG. 9 is a cross-sectional view showing an example of a substrate processing apparatus used in the implementation of the first embodiment. In this embodiment, the substrate processing apparatus 100 is configured as a film-forming apparatus that forms a silicon-containing film at a low temperature on the second surface opposite to the first surface where the devices of the substrate W are formed by capacitively coupled plasma.

[0030] The substrate processing apparatus 100 has a substantially cylindrical shape and has a chamber 10 that defines a processing space 11. The chamber 10 is made of metal, for example, aluminum whose surface has been anodized, and is provided with safety installations.

[0031] At the bottom of the chamber 10, a columnar metal support base 14 is disposed via an insulating plate 12, and a mounting table 16 for mounting a substrate W made of metal, for example, aluminum, is provided on the support base 14. The mounting table 16 constitutes a lower electrode. The mounting table 16 has an electrostatic chuck 18 at the upper part. The electrostatic chuck 18 has a structure in which an electrode 20 is provided inside an insulator. By applying a DC voltage from an adsorption DC power supply 22 to the electrode 20, the substrate W is adsorbed and held by an electrostatic force such as a Coulomb force. The substrate W is placed on the mounting table 16 such that the second surface becomes a gas supply surface.

[0032] A focus ring 24 made of a conductive material, for example, silicon, is disposed around the electrostatic chuck 18. Cylindrical inner wall members 26 made of an insulator, for example, quartz, are provided on the side surfaces of the mounting table 16 and the support base 14.

[0033] Inside the support table 14, a refrigerant chamber 28 is provided. In the refrigerant chamber 28, low-temperature refrigerant is circulated and supplied from a chiller unit (not shown) provided outside through pipes 30a and 30b, and the temperature of the substrate W on the mounting table 16 is controlled to a low temperature, for example, -30°C, at which the higher-order silane gas supplied as the film-forming gas liquefies. Further, a heat transfer gas, for example, He gas, is supplied between the upper surface of the electrostatic chuck 18 and the back surface of the substrate W through the gas supply line 32.

[0034] Above the mounting table 16, which is the lower electrode, an upper electrode 34 is provided so as to face the mounting table 16. The upper electrode 34 is supported above the chamber 10 through an insulating shielding member 43. The upper electrode 34 is composed of an electrode plate 36 that forms a facing surface with the mounting table 16 and has a large number of gas discharge holes 37, and an electrode support 38 with a water-cooling structure that detachably supports the electrode plate 36. The electrode plate 36 is made of a conductor, for example, silicon. Inside the electrode support 38, a gas diffusion chamber 40 is provided, and a large number of gas flow holes 41 communicating with the gas discharge holes 37 extend downward from the gas diffusion chamber 40. The electrode support 38 is formed with a gas inlet 42 for guiding a gas such as a film-forming gas into the gas diffusion chamber 40, and a gas pipe 51 extending from a gas supply unit 50 described later is connected to this gas inlet 42. That is, the upper electrode 34 is configured as a shower head for introducing a gas such as a film-forming gas into the processing space 11.

[0035] A first high-frequency power source 88 for plasma generation is electrically connected to the upper electrode 34. A matching unit 87 is interposed in a power supply line 89 that supplies power from the first high-frequency power source 88 to the upper electrode 34. When high-frequency power is supplied from the first high-frequency power source 88 to the upper electrode 34, capacitively coupled plasma is generated between the mounting table 16, which is the lower electrode, and the upper electrode 34. On the other hand, a second high-frequency power source 91 for bias application for drawing ions into the substrate W is electrically connected to the mounting table 16, which is the lower electrode. A matching unit 90 is interposed in a power supply line 92 that supplies power from the second high-frequency power source 91 to the mounting table 16, which is the lower electrode. The matching units 87 and 90 are for matching the load (plasma) impedance to the impedances on the first and second high-frequency power source 88 and 91 sides, respectively. The first high-frequency power source 88 for plasma generation has a higher frequency than the second high-frequency power source 91 for bias application.

[0036] The gas supply unit 50 supplies a higher-order silane gas, which is a film-forming gas for forming a silicon-containing film on the second surface of the substrate W. Further, from the gas supply unit 50, a purge gas, a pressure-regulating gas, and a plasma generation gas composed of a rare gas such as Ar gas are also supplied. Additionally, H2 gas or an oxygen-containing gas may be supplied. Higher-order silanes include Si2H6, Si3H8, Si4H 10 etc., represented by the general formula Si n H 2n+2 (n is a positive integer of 2 or more), and any of these can be used. However, by using those with n of 4 or more, a film having a large shrinking ability can be obtained. The gas supply unit 50 has gas supply sources corresponding to the plurality of gases to be supplied, and individual pipes extending from each gas supply source are connected to the gas pipe 51. An opening / closing valve and a flow controller are interposed in each individual pipe.

[0037] An exhaust port 60 is provided at the bottom of the chamber 10, and an exhaust device 64 is connected to the exhaust port 60 via an exhaust pipe 62. The exhaust device 64 includes an automatic pressure control valve and a vacuum pump, and is configured to evacuate the inside of the chamber 10 and control it to a desired degree of vacuum. An inlet / outlet 65 for loading and unloading the substrate W with respect to the chamber 10 is provided on the side wall of the chamber 10, and the inlet / outlet 65 is opened and closed by a gate valve 66.

[0038] The substrate processing apparatus 100 has a control unit 70. The control unit 70 is composed of a computer and includes a main control unit equipped with a CPU, an input device (such as a keyboard and a mouse), an output device (such as a printer), a display device (such as a display), and a storage device (a storage medium). The main control unit controls, for example, the high-frequency power supplies 88, 91, the opening / closing valves of the gas supply unit 50, the flow controllers, the automatic pressure control valve, the DC power supply 22 for adsorption, the chiller unit, the gate valve 66, etc. These control operations by the main control unit are executed according to a processing recipe which is a control program stored in a storage medium (such as a hard disk, an optical disk, and a semiconductor memory) built in the storage device.

[0039] In the substrate processing apparatus 100 configured as described above, the substrate W is loaded into the chamber 10 and placed on the mounting table 16 with the second surface facing upward. Then, an inert gas is supplied into the chamber 10 from the gas supply unit 50, and the inside of the chamber 10 is adjusted to a reduced pressure state by the exhaust device 64. In this state, while supplying a plasma generation gas, for example, Ar gas, into the chamber 10 from the gas supply unit 50, high-frequency power for plasma generation from the first high-frequency power supply 88 is applied to the upper electrode 34. Thereby, capacitively coupled plasma is formed between the upper electrode 34 and the mounting table 16 which is the lower electrode. Note that the plasma generation gas may be used as the inert gas for pressure adjustment. Also, high-frequency power for bias application for ion drawing is applied from the second high-frequency power supply 91 to the mounting table 16.

[0040] In this state, by supplying a higher-order silane gas, which is a film-forming gas, from the gas supply unit 50 into the chamber 10, the higher-order silane gas is excited by plasma. The excited higher-order silane gas reaches the second surface of the substrate W maintained at a temperature at which the higher-order silane liquefies, for example, -30°C, and film formation proceeds by gas-phase polymerization at such a low temperature. As a result, a silicon-containing film having a high shrinkage ability as described above and capable of generating a large stress on the second surface of the substrate W is formed.

[0041] <Second Embodiment> [Substrate Processing Method] FIG. 10 is a flowchart showing a substrate processing method according to the second embodiment, and FIG. 11 is a cross-sectional view of the process thereof.

[0042] In this embodiment, first, a substrate 1 having a first surface 2 on which a device is to be formed is prepared (step ST11, FIG. 11(a)). Next, a higher-order silane gas as a film-forming gas is supplied to the second surface 3 on the side opposite to the first surface 2 of the substrate 1, and a silicon-containing film 4 is formed at a temperature at which the higher-order silane gas liquefies (step ST12, FIG. 11(b)). Next, energy 5 is applied to the silicon-containing film 4 to generate stress 6 on the second surface 3 of the substrate 1 (step ST13, FIG. 11(c)).

[0043] In this embodiment, step ST11 and step ST12 are performed in the same manner as step ST1 and step ST2 of the first embodiment.

[0044] In step ST13, energy 5 is applied to the silicon-containing film 4 to generate stress 6 on the second surface 3 of the substrate 1. That is, by applying energy to the silicon-containing film 4, the silicon-containing film 4 shrinks, and stress 6 is generated on the second surface 3 of the substrate 1 due to the force at that time. As described above, since the silicon-containing film 4 has a high shrinkage ability, a large stress can be generated. By generating stress on the second surface 3 of the substrate 1 in this way, the stress generated in the substrate 1 due to film formation when forming a device on the first surface 2 can be relaxed. Also, by generating stress on the second surface 3 of the substrate 1, the substrate 1 can be actively distorted.

[0045] The method of applying energy to the silicon-containing film 4 is not particularly limited, and thermal energy, light energy, etc. can be used. In step ST13, by adjusting the amount of energy applied to the silicon-containing film 4, the shrinkage amount of the silicon-containing film 4 can be adjusted, and the stress generated on the second surface 3 of the substrate 1 can be adjusted.

[0046] Annealing can be used as a method of applying energy to the silicon-containing film. When annealing, for example, the amount of energy can be adjusted by adjusting the annealing temperature and / or the annealing time to adjust the stress. The annealing may be thermal annealing or photo annealing. Annealing can be performed using various things such as a resistance heating element, a heating lamp, an LED, a UV light source, etc. The annealing temperature may be 100 to 400 °C, and particularly has a high effect at 100 to 200 °C. Also, the annealing time may be 10 seconds to 12 hours, for example, about 1 hour.

[0047] In the case of a technique of forming a film that generates stress on the substrate on the second surface of the substrate as in Patent Document 1 by general CVD or ALD, it is difficult to adjust the stress after forming the film. However, in this embodiment, the stress generated in the substrate can be adjusted by a simple method such as annealing.

[0048] In step ST13, energy may be applied to the entire silicon-containing film 4 or locally to the silicon-containing film 4. By applying energy to the entire film, the silicon-containing film 4 can shrink overall and generate stress on the entire second surface 3 of the substrate 1. Also, by applying energy locally, only the portion of the silicon-containing film 4 to which energy is applied shrinks, and stress can be locally generated only in the portion corresponding to that portion of the second surface 3 of the substrate 1. By generating stress locally in this way, for example, local stress existing on the first surface 2 of the substrate 1 can be relaxed.

[0049] After generating stress on the second surface 3 of the substrate 1, the silicon-containing film 4 may be left intact or removed. That is, the silicon-containing film 4 may generate stress on the substrate 1 and then become unnecessary after forming a device on the first surface 2. However, leaving it intact does not adversely affect the device, and leaving it can save the trouble of removal. Also, the silicon-containing film 4 can be easily removed when it is to be removed. Removing it has the advantages of making the whole thinner and improving flatness. Therefore, it is only necessary to determine whether to leave the silicon-containing film 4 or remove it according to the requirements during device formation. When removing the silicon-containing film 4, after the step of applying energy 5 to the silicon-containing film 4 to generate stress 6 on the second surface 3 of the substrate 1 (step ST13), a step of removing the silicon-containing film 4 is carried out.

[0050] [Substrate Processing System] FIG. 12 is a plan view schematically showing an example of a substrate processing system used in the implementation of the second embodiment. The substrate processing system 300 shown in FIG. 12 is a system having a cluster structure (multi-chamber type), and includes a substrate processing apparatus 310, an annealing apparatus 320, a transfer chamber 330, a transfer apparatus 340, a load lock chamber 350, a loader module 360, and an overall control unit 370.

[0051] The substrate processing apparatus 310 supplies a higher-order silane gas as a film-forming gas to the second surface of the substrate W at a temperature at which the gas is liquefied, and forms a silicon-containing film on the second surface. It may be configured in the same manner as the substrate processing apparatus 100 of the first embodiment.

[0052] The annealing apparatus 320 anneals the silicon-containing film formed on the second surface of the substrate to impart energy to the silicon-containing film and generate stress on the second surface of the substrate W. An example of the annealing apparatus 320 will be described later.

[0053] The transfer chamber 330 is maintained in a predetermined vacuum atmosphere, and a transfer device 340 for transferring the substrate W is provided inside. The substrate processing apparatus 310, the annealing apparatus 320, and the load lock chamber 350 described above are connected to the transfer chamber 330 via a gate valve (not shown). The transfer device 340 transfers the substrate W among the substrate processing apparatus 310, the annealing apparatus 320, and the load lock chamber 350.

[0054] The load lock chamber 350 is provided between the loader module 360 and the transfer chamber 330 and is capable of switching between an atmospheric atmosphere and a vacuum atmosphere. The loader module 360 is connected to the load lock chamber 350 via a gate valve (not shown) and is arranged adjacent thereto, and is in an atmospheric atmosphere, and a transfer device (not shown) is provided. A load port is provided on the wall surface of the loader module 360 opposite to the load lock chamber 350, and a carrier (for example, a FOUP (Front Opening Unified Pod)) containing or from which the substrate W is accommodated is attached to the load port. The transfer device of the loader module 360 transfers the substrate W between the load lock chamber 350 and the carrier attached to the load port.

[0055] The overall control unit 370 is composed of a computer and includes a main control unit with a CPU, an input device (such as a keyboard and a mouse), an output device (such as a printer), a display device (such as a display), and a storage device (a storage medium). The main control unit controls the processing of the substrate processing device 310, the annealing device 320, the transfer device 340 and the transfer device of the loader module 360, and the opening and closing of the gate valve. The overall control unit 370 may be configured as a higher-level control unit of the control units of the substrate processing device 310 and the annealing device 320.

[0056] In the substrate processing system 300, first, a substrate W is taken out from a carrier connected to a load port by a transfer device (not shown) in the loader module 360 and carried into the load lock chamber 350 in the atmospheric atmosphere.

[0057] Then, the load lock chamber 350 is set to a vacuum atmosphere, and the substrate W in the load lock chamber 350 is carried into the substrate processing device 310 by the transfer device 340. In the substrate processing device 310, a higher-order silane gas as a film-forming gas is supplied at a temperature at which it liquefies on the second surface of the substrate W, and a silicon-containing film is formed on the second surface. Then, the substrate W on which the silicon-containing film is formed is carried out from the substrate processing device 310 by the transfer device 340 and carried into the annealing device 320. In the annealing device 320, the silicon-containing film formed on the second surface of the substrate W is annealed and shrunk to generate stress on the second surface of the substrate. Then, the substrate W that has been annealed is carried out by the transfer device 340 and carried to the load lock chamber 350.

[0058] Then, the load lock chamber 350 is set to the atmospheric atmosphere, and the substrate W in the load lock chamber 350 is returned to the carrier by the transfer device in the loader module 360.

[0059] The above processes are performed simultaneously and in parallel for a plurality of substrates W to complete the processing of the plurality of substrates W in the carrier.

[0060] [Annealing Device] FIG. 13 is a cross-sectional view showing an example of the annealing device 320. The annealing apparatus 320 includes a chamber (not shown), a mounting table 110 for mounting a substrate W provided in the chamber, a heating mechanism 140 for heating by an LED, and a control unit 160.

[0061] The mounting table 110 has a top plate 120 as a top plate portion and a flow path forming member 130. The top plate 120 is attached on the flow path forming member 130 via a seal ring 131. The substrate W has a silicon-containing film formed on its second surface and is adsorbed and held on the surface of the top plate 120 with the silicon-containing film facing down.

[0062] A plurality of temperature sensors 121 are embedded in the top plate 120 at positions spaced apart from each other in a plan view. The top plate 120 is formed in a disc shape having a diameter approximately the same as that of the substrate W and is made of, for example, SiC. SiC has high thermal conductivity and Young's modulus, and also has a high absorption efficiency for the light from the LED 141 of the heating mechanism 140 described later, and can be efficiently heated by the light from the heating mechanism 140.

[0063] The flow path forming member 130 is formed in a disc shape having substantially the same diameter as the top plate 120 and is made of a material transparent to the wavelength of the light from the LED described later. A groove for flowing a temperature control medium is formed in the upper portion of the flow path forming member 130, and the groove is covered by the top plate 120 to form a temperature control medium flow path R. A supply port 132 for supplying the temperature control medium to the temperature control medium flow path R and a discharge port 133 for discharging the temperature control medium are formed in the side portion of the flow path forming member 130. A temperature control medium supply pipe 150 and a temperature control medium discharge pipe 151 are connected to these respectively, and the temperature control medium is circulated and supplied to the temperature control medium flow path R. A valve 152 is provided in the temperature control medium supply pipe 150. By flowing a temperature control medium at a predetermined temperature through the temperature control medium flow path R, the temperature of the base of the mounting table 110 is adjusted to a predetermined temperature.

[0064] The heating mechanism 140 is configured as a light irradiation mechanism, faces the surface of the mounting table 110 opposite to the substrate mounting surface, i.e., the lower surface of the flow path forming member 130, and is arranged to correspond to the substrate W placed on the top plate 120. The heating mechanism 140 has a plurality of LEDs 141 as a heat source, irradiates the top plate 120 of the mounting table 110 with light from the LEDs, and heats the silicon-containing film of the substrate W placed thereon through the top plate 120.

[0065] Each LED 141 emits, for example, near-infrared light. The light emitted from the LED 141 passes through the flow path forming member 130 of the mounting table 110 which is made of a light-transmitting member. The temperature control medium flowing through the temperature control medium flow path R is made of a material that transmits the light from the LED 141, and the light that has passed through the flow path forming member 130 and the temperature control medium is incident on the top plate 120. When the light from the LED 141 is near-infrared light, polycarbonate, quartz, polyvinyl chloride, acrylic resin, or glass can be used as the light-transmitting member constituting the flow path forming member 130.

[0066] The heating mechanism 140 is configured by arranging a plurality of LED units 143 in which a plurality of LEDs 141 as a heat source are unitized, substantially without gaps, on the base portion 142. Each LED unit 143 can perform on / off control and light amount control separately and independently, and it is possible to heat the substrate W uniformly or locally. Also, by controlling the light amount of the LEDs 141 of the LED unit 143, the annealing temperature of the substrate W can be controlled. The base portion 142 may be provided with a refrigerant flow path and be cooled by the refrigerant.

[0067] The control unit 160 is composed of a computer and includes a main control unit equipped with a CPU, an input device (such as a keyboard and a mouse), an output device (such as a printer), a display device (such as a display), and a storage device (a storage medium). The main control unit performs, for example, on / off control of the LED 141 for each LED unit 143 and control of the light amount, and flow rate control of the temperature control medium. These control operations by the main control unit are executed according to a processing recipe which is a control program stored in a storage medium (such as a hard disk, an optical disk, and a semiconductor memory) built in the storage device.

[0068] With the annealing apparatus 320 configured as described above, annealing treatment can be performed on the entire or a part of the silicon-containing film formed on the second surface of the substrate W, the silicon-containing film can be shrunk, and stress can be generated on the entire or a part of the second surface of the substrate W.

[0069] Note that the above substrate processing system 300 is an example in which a device for forming a silicon-containing film and a device for performing annealing for stress generation are connected to a transfer chamber in a cluster structure, and the processing by these is performed in-situ. However, the present invention is not limited to this, and these devices may be provided separately to configure a substrate processing system. Further, the annealing apparatus is not limited to one using an LED, and a resistance heating element, a heating lamp, or a UV light source may be used. Further, as long as it can apply energy to the silicon-containing film, it is not limited to the annealing apparatus.

[0070] <The Third Embodiment> [Substrate Processing Method] FIG. 14 is a flowchart showing a substrate processing method according to the third embodiment, and FIG. 15 is a sectional view of the process thereof.

[0071] In this embodiment, first, a substrate 1 having a first surface 2 on which a device is to be formed is prepared (step ST21, FIG. 15(a)). Next, the stress distribution on the second surface 3 opposite to the first surface 2 of the substrate 1 is measured (step ST22). This measurement of the stress distribution may be performed over the entire second surface 3 of the substrate 1 or a part thereof. The measurement of the stress distribution can be performed, for example, by scanning a stress measurement unit 7 on the second surface 3 of the substrate 1 as shown in FIG. 15(b). Next, a high-order silane gas as a film-forming gas is supplied to the second surface 3 of the substrate 1, and a silicon-containing film 4 is formed at a temperature at which the high-order silane gas liquefies (step ST23, FIG. 15(c)). Next, according to the stress distribution measured in step ST22, energy 5 is locally applied to the silicon-containing film 4 to locally generate stress 6 on the second surface 3 of the substrate 1 so that the measured stress distribution is relaxed (step ST24, FIG. 15(d)).

[0072] In this embodiment, step ST21 and step 23 are performed in the same manner as step ST1 and step ST2 of the first embodiment.

[0073] In step ST22, the method for measuring the stress distribution on the second surface 3 of the substrate 1 is not particularly limited, but measurement by Raman spectroscopy can be used. When the substrate is, for example, a Si substrate, the stress of the substrate 1 is obtained by irradiating the substrate 1 with laser light to obtain a spectrum of Raman scattered light (Raman spectrum), and calculating according to the above (1) from the shift amount (Raman shift) from 520 (cm -1 ) which is the peak of the Si crystal (crystal without stress). The stress distribution on the second surface 3 of the substrate 1 can be measured by using a device having a laser light source, an objective lens, a spectroscope, a detector, etc. as a stress measurement unit and scanning the laser light on the second surface 3. That is, the stress distribution can be obtained by scanning laser light on the second surface 3 of the substrate 1, measuring the Raman spectrum from the Raman scattered light, obtaining the Raman shift of the silicon peak at each position on the second surface 3 of the substrate 1, and calculating the stress at each position.

[0074] In step ST24, based on the stress distribution on the second surface 3 of the substrate 1 measured in step ST22, energy is locally applied to the silicon-containing film 4 to shrink it, and stress is generated on the second surface 3 of the substrate 1 so that the measured stress distribution is relaxed. That is, in step ST24, energy is locally applied to the silicon-containing film 4 such that stress is generated at the location on the second surface 3 of the substrate 1 where stress was measured, and the stress distribution is relaxed. As such a method of locally applying energy, for example, local annealing using an LED as described above can be used. Also, a method of performing local annealing by scanning a UV light source or a heating lamp may be used.

[0075] As described above, conventionally, when forming a device on one side (the first surface) of a wafer as a substrate, film formation and pattern formation by etching are repeated. Recently, the patterns to be formed have become more complex, and after or during the formation of a device with a desired pattern, complex stress occurs in the film constituting the pattern, and accordingly, a complex and non-uniform stress distribution also occurs in the substrate.

[0076] Therefore, in this embodiment, the stress distribution on the second surface 3 of the substrate 1 is measured, and then a silicon-containing film 4 having a large shrinkage ability as described above is formed, and local annealing or the like is performed on the silicon-containing film 4 according to the stress distribution. By this local annealing or the like, the portion of the silicon-containing film 4 where annealing or the like has been performed shrinks, and local stress is generated on the second surface 3 of the substrate 1 so as to relax the measured stress distribution of the substrate.

[0077] A stress relaxation film formed on the second surface of a substrate by general CVD or ALD as described in Patent Document 1 alone cannot cope with such a complex and non-uniform stress distribution caused by such a pattern. In order to use such a technique for relaxing a non-uniform stress distribution, pattern formation using, for example, photolithography technology is required for the stress relaxation film, which becomes an extremely complex process and its effect is also limited. On the other hand, in the present embodiment, the non-uniform stress can be relaxed by a simple method of only performing annealing or the like according to the measured stress distribution. Further, in the present embodiment, a large stress can be generated by shrinking a silicon-containing film, and the magnitude of the generated stress can be adjusted, so that the stress relaxation effect corresponding to the non-uniform stress distribution is large.

[0078] [Substrate processing system] FIG. 16 is a plan view schematically showing an example of a substrate processing system used in the implementation of the third embodiment. The substrate processing system 400 shown in FIG. 16 is a system having a cluster structure (multi-chamber type), and includes a substrate processing apparatus 410, an annealing apparatus 420, a stress measurement apparatus 480, a transfer chamber 430, a transfer apparatus 440, a load lock chamber 450, a loader module 460, and an overall control unit 470.

[0079] The substrate processing apparatus 410 supplies a higher-order silane gas as a film-forming gas to the second surface of the substrate W at a temperature at which the gas is liquefied, and forms a silicon-containing film on the second surface of the substrate W, and may be configured in the same manner as the substrate processing apparatus 100 of the first embodiment.

[0080] The annealing apparatus 420 locally anneals the silicon-containing film formed on the second surface of the substrate W according to the stress distribution measured by the stress measurement apparatus 480 described below, and locally generates stress on the second surface of the substrate W so that the measured stress is relaxed. The annealing apparatus 420 may be configured in the same manner as the annealing apparatus 320 of the second embodiment that enables local annealing.

[0081] As shown in FIG. 17, for example, the stress measurement device 480 includes a stage 501 for placing the substrate W, a laser light source 502, an objective lens 503, a spectroscope 504, a multi-channel detector 505 for measuring the spectrum, and a control unit 506. The substrate W is placed on the stage 501 with the second surface facing up. The stage 501 is movable freely within a plane and can scan the laser light on the second surface of the substrate W. It is also possible to move the optical system to scan the laser light. The laser light from the laser light source 502 is irradiated onto the second surface of the substrate W through the objective lens 503. Then, the Raman scattered light generated from the second surface of the substrate W is condensed by the objective lens 503 and guided to the spectroscope 504, and the Raman spectrum is measured by the multi-channel detector 505. The control unit 506 controls each component of the stress measurement device 480 and functions as an arithmetic unit. The control unit 506 obtains the Raman shift of the peak of silicon from the Raman spectrum and calculates the stress.

[0082] The transfer chamber 430 is maintained in a predetermined vacuum atmosphere, and a transfer device 440 for transferring the substrate W is provided inside. The transfer chamber 430 is connected via a gate valve (not shown) to the above-described substrate processing device 410, annealing device 420, stress measurement device 480, and load lock chamber 450. The transfer device 440 transfers the substrate W among the substrate processing device 410, annealing device 420, stress measurement device 480, and load lock chamber 450.

[0083] The load lock chamber 450 and loader module 460 are configured in the same manner as the load lock chamber 350 and loader module 360 of the substrate processing system 300 of the second embodiment. A transfer device is provided in the loader module 460, and the transfer device transfers the substrate W between the load lock chamber 450 and the carrier attached to the load port.

[0084] The overall control unit 470 is composed of a computer and is configured in the same manner as the overall control unit 370 in the substrate processing system 300 of the second embodiment. It controls the processing of the substrate processing apparatus 410, the annealing apparatus 420, and the stress measurement apparatus 480, the transfer devices of the transfer apparatus 440 and the loader module 460, and the opening and closing of the gate valve. Further, the overall control unit 470 stores the stress distribution measured by the stress measurement apparatus 480 and gives a command to the annealing site of the annealing apparatus 420 according to it. The overall control unit 470 may be configured as a higher-level control unit of the control units of the substrate processing apparatus 410, the annealing apparatus 420, and the stress measurement apparatus 480.

[0085] In the substrate processing system 400, first, the substrate W is taken out from a carrier connected to the load port by a transfer device (not shown) in the loader module 460 and carried into the load lock chamber 450 in the atmospheric atmosphere. The device may be formed on the first surface of the substrate W, or a pattern during the formation of the device may be formed.

[0086] Then, the load lock chamber 450 is set to a vacuum atmosphere, and the substrate W in the load lock chamber 450 is carried into the stress measurement device 480 with the second surface facing up by the transfer device 440. In the stress measurement device 480, the stress distribution of the entire second surface or a part of the second surface of the substrate W is measured. At this time, the measurement result of the stress distribution is stored in the overall control unit 470. Then, the substrate W whose stress distribution has been measured by the transfer device 440 is unloaded from the stress measurement device 480 and carried into the substrate processing device 410. In the substrate processing device 410, a higher-order silane gas as a film-forming gas is supplied to the second surface of the substrate W at a temperature at which it liquefies, and a silicon-containing film is formed on the second surface. Then, the substrate W on which the silicon-containing film has been formed by the transfer device 440 is unloaded from the substrate processing device 410 and carried into the annealing device 420. In the annealing device 420, local annealing is performed on the silicon-containing film 4 according to the stress distribution measurement result of the stress measurement device 480 stored in the overall control unit 470. By this local annealing, the annealed portion of the silicon-containing film shrinks, and local stress is generated on the second surface of the substrate W so as to relax the stress distribution of the substrate W measured by the stress measurement device 480. Then, the substrate W that has been annealed by the transfer device 440 is unloaded and carried to the load lock chamber 450.

[0087] Then, with the load lock chamber 450 set to an atmospheric atmosphere, the substrate W in the load lock chamber 450 is returned to the carrier by the transfer device in the loader module 460.

[0088] The above-described processes are performed simultaneously and in parallel for a plurality of substrates W to complete the processing of the plurality of substrates W in the carrier.

[0089] Note that the above substrate processing system 400 is an example in which an apparatus for forming a silicon-containing film, an apparatus for annealing to generate stress, and a stress measurement apparatus are connected to a transfer chamber in a cluster structure, and the processing by these is performed in-situ. However, the present invention is not limited to this, and these apparatuses may be provided separately to constitute a substrate processing system. Further, the annealing apparatus is not limited to one using an LED, and any apparatus capable of performing local heating may be used, such as a UV light source or a heating lamp. Further, it is not limited to the annealing apparatus as long as it can apply energy to the silicon-containing film.

[0090] <Other applications> As described above, the embodiments have been described. However, the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and gist of the appended claims.

[0091] For example, in the above embodiment, the Si film and the SiO2 film are exemplified as the silicon-containing films formed on the second surface of the substrate. However, the present invention is not limited to this, and other Si-containing films such as SiN films may be used.

[0092] Further, in the above embodiment, as the substrate processing apparatus for forming a silicon-containing film, an apparatus that cools the substrate by a mounting table and processes using capacitively coupled plasma is exemplified. However, the present invention is not limited to this. For example, regarding the cooling method of the substrate, if the film can be formed at a temperature at which higher-order silane gas liquefies, the method is not limited to cooling by the mounting table. Further, regarding the plasma, it is not limited to capacitively coupled plasma, and inductively coupled plasma, microwave plasma, or remote plasma may be used. Furthermore, if the film can be formed at a temperature at which higher-order silane gas liquefies, a film formation method without using plasma may be used.

[0093] Furthermore, the annealing apparatus and the stress measurement apparatus are merely examples, and their configurations are not limited as long as the intended purpose can be achieved.

Explanation of reference numerals

[0094] 1; Substrate 2; First surface 3; Second surface 4; Silicon-containing film 5; Energy 6; Stress 7; Stress measurement unit 10; Chamber 16; Mounting table (lower electrode) 28; Refrigerant chamber 34; Upper electrode 50; Gas supply unit 70, 160, 506; Control unit 88, 91; High-frequency power supply 100, 310, 410; Substrate processing apparatus 300, 400; Substrate processing system 320, 420; Annealing apparatus 330, 430; Transfer chamber 340, 440; Transfer device 350, 450; Load lock chamber 360, 460; Loader module 370, 470; Overall control unit 480; Stress measurement device W; Substrate

Claims

1. Preparing a substrate having a first surface on which a device is to be formed; Using a higher-order silane gas as a film-forming gas to form a silicon-containing film on a second surface opposite to the first surface of the substrate at a temperature at which the higher-order silane gas liquefies; A substrate processing method comprising:

2. The step of forming the silicon-containing film includes placing the substrate on a mounting table in a chamber, maintaining the mounting table at a temperature at which the higher-order silane gas liquefies, introducing the higher-order silane gas into the chamber and supplying it to the second surface of the substrate, thereby forming the silicon-containing film on the second surface. The substrate processing method according to claim 1.

3. The substrate processing method according to claim 2, wherein the higher-order silane gas is supplied to the second surface of the substrate in a state excited by plasma.

4. The substrate processing method according to claim 1, further comprising, after the step of forming the silicon-containing film, applying energy to the silicon-containing film to generate stress on the second surface of the substrate.

5. The substrate processing method according to claim 4, wherein when energy is applied to the silicon-containing film, the silicon-containing film shrinks, thereby generating stress on the second surface of the substrate.

6. The substrate processing method according to claim 5, wherein the shrinkage amount of the silicon-containing film is controlled by the amount of energy applied to the silicon-containing film, and the stress generated on the second surface of the substrate is controlled.

7. The substrate processing method according to claim 5, wherein energy is applied to the silicon-containing film by annealing the silicon-containing film.

8. The substrate processing method according to claim 7, wherein the shrinkage amount of the silicon-containing film is controlled by the temperature and / or time of the annealing, and the stress generated on the second surface of the substrate is controlled.

9. Before the step of forming the silicon-containing film, further comprising a step of measuring the stress distribution on the second surface; The step of applying energy to the silicon-containing film to generate stress on the second surface of the substrate locally applies energy to the silicon-containing film according to the measured stress distribution, so that locally stress is generated on the second surface of the substrate to relieve the measured stress distribution. The substrate processing method according to claim 4.

10. The step of measuring the stress distribution is the substrate processing method according to claim 9, wherein the stress on the second surface of the substrate is calculated from the shift amount of the crystal peak of the Raman spectrum by Raman spectroscopy.

11. The step of applying energy to the silicon-containing film to generate stress on the second surface of the substrate is to arrange a plurality of LEDs as a heating source and unitize them to form an LED unit, and arrange a plurality of the LED units corresponding to the silicon-containing film formed on the second surface of the substrate, and by turning the LED units on and off, locally heating the silicon-containing film, the substrate processing method according to claim 9.

12. A chamber for accommodating a substrate having a first surface on which a device is formed, A mounting table for mounting the substrate such that a second surface opposite to the first surface of the substrate serves as a gas supply surface, A gas supply unit for supplying a higher-order silane gas as a film-forming gas to the substrate, Cooling means for cooling the substrate to a temperature at which the higher-order silane gas liquefies via the mounting table, having A substrate processing apparatus that supplies the higher-order silane gas to the second surface of the substrate and forms a silicon-containing film on the second surface of the substrate.

13. The substrate processing apparatus according to claim 12, further comprising plasma generation means for exciting the higher-order silane gas.

14. The substrate processing apparatus according to claim 12, and An apparatus for applying energy to the silicon-containing film formed by the substrate processing apparatus to generate stress on the second surface of the substrate, having a substrate processing system.

15. The apparatus for applying energy to the silicon-containing film to generate stress on the second surface of the substrate is an annealing apparatus, the substrate processing system according to claim 14.

16. The annealing apparatus controls the stress generated on the second surface of the substrate according to the temperature and / or time of the annealing, the substrate processing system according to claim 15.

17. Before forming a silicon-containing film by the substrate processing apparatus, it further has a stress measurement device for measuring the stress distribution on the second surface, The apparatus for applying energy to the silicon-containing film to generate stress on the second surface of the substrate locally applies energy to the silicon-containing film according to the measured stress distribution, so that locally stress is generated on the second surface of the substrate such that the measured stress distribution is relaxed, the substrate processing system according to claim 14.

18. The substrate processing system according to claim 17, wherein the stress measurement device calculates the stress on the second surface of the substrate from the amount of shift of the crystal peak of the Raman spectrum by Raman spectroscopy.

19. The device for applying energy to the silicon-containing film to generate stress on the second surface of the substrate has a heating source in which a plurality of LED units are arranged and unitized, and a plurality of the LED units are arranged corresponding to the silicon-containing film formed on the second surface of the substrate, and the silicon-containing film is locally heated by turning the LED units on and off. The substrate processing system according to claim 17.

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