Film-forming raw material mixed gas generating device and film-forming device

Abstract

To provide a production apparatus of a mixed gas of a film deposition raw material capable of vaporizing a film deposition raw material more certainly, and a film deposition apparatus.SOLUTION: A production apparatus of a mixed gas of a film deposition raw material according to an aspect of the present invention includes a film deposition raw material supply unit 11 for supplying a film deposition raw material liquid R1 at a specified flow rate, a carrier gas supply unit 12 for supplying a carrier gas C at a specified flow rate, a main vaporization unit 13 for vaporizing the film deposition raw material by heating the film deposition raw material supplied from the film deposition raw material supply unit and the carrier gas supplied from the carrier gas supply unit, and an auxiliary vaporization unit 14 having a porous vaporization member 141 for capturing droplets of the film deposition raw material carried over into a gas flowing out of the main vaporization unit and vaporizing the captured droplets of the film deposition raw material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film-forming raw material mixed gas generating device and a film-forming device. [Background technology]

[0002] In the manufacture of semiconductor devices and the like, film formation techniques for forming a layer of a desired material on a substrate are widely used. For example, a material that is liquid at room temperature and pressure may be used as a film formation raw material containing atoms that constitute at least a portion of the material to be laminated on a semiconductor substrate. An example of such a liquid film formation raw material is triethoxysilane (TEOS), which is used to form an SiO2 insulating film. When a liquid film formation raw material is used, a device is required to vaporize the film formation raw material and supply it to a reaction chamber together with a carrier gas.

[0003] For example, U.S. Patent No. 6,210,485 discloses an apparatus in which a liquid film-forming raw material (liquid precursor) and a carrier gas are supplied at fixed rates, the supplied film-forming raw material is vaporized and mixed with the carrier gas, and the mixed gas of the vaporized film-forming raw material and the carrier gas is supplied to a reaction chamber. Summary of the Invention [Problem to be solved by the invention]

[0004] When forming a thick film, it is desirable to increase the supply rate of the film-forming raw material in order to improve production efficiency. However, when using a film-forming raw material that is liquid at room temperature and normal pressure, increasing the supply rate of the film-forming raw material may result in the film-forming raw material not being sufficiently vaporized. If the film-forming raw material is not sufficiently vaporized, droplets of the film-forming raw material may be carried over to the reaction chamber and adhere to the surface of the substrate, which may reduce the quality of the formed film. Therefore, a film-forming raw material mixed gas generator and a film-forming apparatus that can more reliably vaporize the film-forming raw material are desired. [Means for solving the problem]

[0005] A film-forming raw material mixed gas generation apparatus according to one embodiment of the present disclosure includes a film-forming raw material supply unit that supplies a liquid film-forming raw material at a predetermined flow rate, a carrier gas supply unit that supplies a carrier gas at a predetermined flow rate, a main vaporization unit that vaporizes the film-forming raw material by heating the film-forming raw material supplied from the film-forming raw material supply unit and the carrier gas supplied from the carrier gas supply unit, and an auxiliary vaporization unit that has a porous vaporization member that captures droplets of the film-forming raw material carried over in the gas flowing out of the main vaporization unit and vaporizes the captured droplets of the film-forming raw material.

[0006] In the film-forming raw material mixed gas generation apparatus according to the aspect of the present disclosure, the porous vaporizing member may be formed of a metal sintered body.

[0007] In the film-forming raw material mixed gas generation device according to one aspect of the present disclosure, the metal sintered body may be formed from a sintered body of fibrous metal.

[0008] The film-forming material mixed gas generating apparatus according to an aspect of the present disclosure may further include an auxiliary heater that heats the auxiliary vaporizing unit.

[0009] In the film-forming material mixed gas generating apparatus according to the aspect of the present disclosure, the auxiliary vaporizing unit may be disposed adjacent to the main vaporizing unit.

[0010] The film-forming raw material mixed gas generating apparatus according to an aspect of the present disclosure may further include a second raw material gas supplying unit that supplies a second raw material gas at a predetermined flow rate downstream of the auxiliary vaporizing unit.

[0011] A film formation apparatus according to another aspect of the present disclosure includes any one of the film formation raw material mixed gas generators and a reaction chamber to which the film formation raw material and the carrier gas are supplied from the film formation raw material mixed gas generator. [Effects of the Invention]

[0012] The film-forming raw material mixed gas generating device and the film-forming apparatus according to an aspect of the present disclosure can vaporize the film-forming raw material more reliably. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a configuration of a film forming apparatus according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. 1 is a schematic diagram showing the configuration of a film forming apparatus 100. As shown in FIG.

[0015] The film forming apparatus 100 includes a film forming raw material mixed gas generator 1 according to one embodiment of the present disclosure, a film forming raw material source 2 that supplies a film forming raw material R1 to the film forming raw material mixed gas generator 1, a carrier gas source 3 that supplies a carrier gas C to the film forming raw material mixed gas generator 1, a second raw material gas source 4 that supplies a second raw material gas R2 to the film forming raw material mixed gas generator 1, and a reaction chamber 5 to which a film forming raw material mixed gas Gm is supplied, which is a mixture of the film forming raw material R1 vaporized from the film forming raw material mixed gas generator 1, the carrier gas C, and the second raw material gas R2.

[0016] The film forming raw material mixed gas generator 1 includes a film forming raw material supply unit 11 that supplies a liquid film forming raw material R1 at a predetermined flow rate, a carrier gas supply unit 12 that supplies a carrier gas C at a predetermined flow rate, a main vaporization unit 13 that vaporizes the film forming raw material R1 by heating the film forming raw material R1 supplied from the film forming raw material supply unit 11 and the carrier gas C supplied from the carrier gas supply unit 12, thereby generating a pre-mixed gas Gp that is a mixed gas of the vaporized film forming raw material R1 and the carrier gas C, an auxiliary vaporization unit 14 that captures droplets of the film forming raw material R1 carried over in the pre-mixed gas Gp flowing out from the main vaporization unit and vaporizes the captured droplets of the film forming raw material R1, an auxiliary heater 15 that heats the auxiliary vaporization unit 14, an outflow valve 16 that can stop the outflow of the pre-mixed gas Gp, and a second film forming raw material gas supply unit 17 that is located downstream of the auxiliary vaporization unit 14 and supplies a second film forming raw material gas R2 at a predetermined flow rate.

[0017] The film-forming raw material supply unit 11 adjusts the flow rate of the film-forming raw material R1 supplied from the film-forming raw material source 2 to a predetermined flow rate in advance. The film-forming raw material supply unit 11 may be configured to include a flow sensor and a flow rate adjustment valve. The film-forming raw material R1 is selected depending on the material of the film to be formed, and may be, for example, triethoxysilane (TEOS).

[0018] The carrier gas supply unit 12 adjusts the flow rate of the carrier gas C supplied from the carrier gas source 3 to a predetermined flow rate in advance. The carrier gas supply unit 12 may be configured to include a flow sensor and a flow rate adjustment valve. As the carrier gas C, an inert gas such as helium, argon, or nitrogen is used.

[0019] The main vaporizer 13 vaporizes the film forming raw material R1 by heating the supplied film forming raw material R1 and carrier gas C. For this purpose, the main vaporizer 13 may be configured to include a heat source such as an electric heater. The main vaporizer 13 preferably has a heat transfer structure that can provide sufficient heat to the film forming raw material R1 supplied from the film forming raw material supply unit 11 and the carrier gas C supplied from the carrier gas supply unit 12. The heating temperature of the main vaporizer 13 is preferably equal to or higher than the boiling point of the film forming raw material R1, and more preferably 5°C to 20°C higher than the boiling point of the film forming raw material R1.

[0020] The main vaporization unit 13 may be configured to generate a gas flow, such as a spiral gas, in the flow of the carrier gas C, which can promote vaporization by shearing and breaking down the liquid of the film-forming raw material R1.

[0021] The auxiliary vaporization unit 14 has a porous vaporization member 141 made of a porous body having pores through which droplets of the film forming source material R1 cannot pass. This porous vaporization member 141 traps droplets of the film forming source material R1 contained in the pre-mixed gas Gp flowing out from the main vaporization unit 13, thereby preventing the droplets of the film forming source material R1 from being introduced into the reaction chamber 5. Furthermore, the droplets of the film forming source material R1 trapped in the porous vaporization member 141 permeate the porous vaporization member 141, thereby increasing the contact area with the pre-mixed gas Gp passing through the porous vaporization member 141 and lengthening the residence time within the porous vaporization member 141, thereby facilitating vaporization.

[0022] It is considered that the pre-mixed gas Gp flowing out from the main vaporizer 13 has sufficient thermal energy to vaporize droplets of the contained film forming raw material R1 by being heated in the main vaporizer 13. Therefore, by retaining the droplets of the film forming raw material R1 in the auxiliary vaporizer 14, the film forming raw material R1 in the gas phase can be vaporized by the heat of the film forming raw material R1 in the gas phase and the carrier gas.

[0023] More specifically, the liquid film forming source R1 trapped in the auxiliary vaporizer 14 can be vaporized if the saturated vapor pressure of the liquid film forming source R1 trapped in the auxiliary vaporizer 14 is higher than the partial vapor pressure of the film forming source R1 in the pre-mixed gas Gp passing through the auxiliary vaporizer 14. If the amount of film forming source R1 vaporized from the auxiliary vaporizer 14 is greater than the amount of liquid film forming source R1 newly flowing out from the main vaporizer 13, an equilibrium state can be achieved in which the auxiliary vaporizer 14 is not clogged and a film forming source mixed gas Gm containing a predetermined amount of film forming source R1 is generated.

[0024] The porous body forming the porous vaporization member 141 of the auxiliary vaporization section 14 is preferably a sintered metal body. By forming the porous vaporization member 141 from a sintered metal body, the thermal conductivity of the porous vaporization member 141 can be increased, allowing heat to be transferred to the captured droplets of the film formation raw material R1, thereby enabling rapid vaporization. The metal forming the porous vaporization member 141 is preferably a chemically stable metal such as stainless steel.

[0025] Furthermore, the metal sintered body forming the porous vaporizer 141 is preferably a fibrous metal sintered body. A fibrous metal sintered body can increase the porosity while reducing the pore diameter. This can more reliably prevent the passage of droplets of the film-forming raw material R1 while reducing the resistance to the premixed gas Gp, allowing the captured film-forming raw material R1 to be quickly vaporized. The filtration accuracy of the porous vaporizer 141 is preferably, for example, 0.5 μm or less. Furthermore, by increasing the volume of the porous vaporizer 141, the vaporization capacity of the porous vaporizer 141 (the amount of film-forming raw material R1 that can be vaporized per unit time) can be increased. Because the vaporization capacity of the porous vaporizer 141 depends on various conditions, the specifications of the porous vaporizer 141 can be determined through experiments or actual operation.

[0026] The auxiliary vaporizer 14 may have a flange 142 for fixing the porous vaporizer 141 within the flow path. The porous vaporizer 141 may be formed in a cylindrical shape with one end sealed and the flange 142 connected to the other end. By forming the porous vaporizer 141 and the flange 142 from metal, heat from the auxiliary heater 15 can be conducted to the porous vaporizer 141, thereby quickly vaporizing the captured droplets of the film-forming raw material R1. Furthermore, by providing the flange 142 at one end of the cylindrical porous vaporizer 141, the auxiliary vaporizer 14 can be configured by placing the porous vaporizer 141 inside the inlet flow path of the outflow valve 16, etc. This eliminates the need for a dedicated housing for the auxiliary vaporizer 14, thereby enabling the film-forming raw material mixed gas generator 1 to be made more compact.

[0027] The auxiliary vaporizer 14 is preferably disposed adjacent to the main vaporizer 13. In this embodiment, no branch or other equipment is provided in the path between the main vaporizer 13 and the auxiliary vaporizer 14. This allows the auxiliary vaporizer 14 to effectively utilize the thermal energy of the premixed gas Gp flowing out from the main vaporizer 13 to promote the vaporization of the droplets of the film-forming raw material R1 captured by the porous vaporizer member 141.

[0028] The auxiliary heater 15 is disposed to directly heat the auxiliary vaporizer 14 or indirectly heat the auxiliary vaporizer 14 by heating components near the auxiliary vaporizer 14. As described above, the premixed gas Gp flowing from the main vaporizer 13 to the auxiliary vaporizer 14 has sufficient heat. Therefore, the heating temperature of the auxiliary heater 15 may be lower than the boiling point of the film-forming raw material as long as it can suppress a temperature drop in the auxiliary vaporizer 14 due to heat radiation to the atmosphere. Specifically, the heating temperature of the auxiliary heater 15 can be set to a temperature approximately 20°C to 40°C lower than the boiling point of the film-forming raw material.

[0029] The outlet valve 16 selects whether to supply the pre-mixed gas Gp or stop the supply of the pre-mixed gas Gp depending on the operating state of the reaction chamber 5. The outlet valve 16 can also be used to apply an appropriate back pressure to the main vaporization section 13 to stabilize the vaporization of the film-forming raw material R1.

[0030] The second source gas supply unit 17 further adds the second source gas R2 to the preparatory mixed gas Gp flowing out from the outlet valve 16. As a result, a film forming source mixed gas Gm, which is a mixed gas of the preparatory mixed gas Gp and the second source gas R2, is generated. The film forming source mixed gas generator 1 of this embodiment supplies the film forming source mixed gas Gm generated in this manner to the reaction chamber 5.

[0031] The second source gas supply unit 17 may be configured to include a flow sensor and a flow control valve. The second source gas supply unit 17 mixes the second source gas R2, which may be at a lower temperature, after the film forming source material R1 has been completely vaporized by the auxiliary vaporizer 14. This allows the film forming source material mixed gas generator 1 to effectively utilize the heat of the main vaporizer 13 to vaporize the liquid film forming source material R1. The temperature of the second source gas R2 is set to a temperature that does not condense the vapor of the film forming source material during mixing. Examples of the second source gas R2 that can be used include oxygen, argon, helium, and nitrogen gas.

[0032] The film forming raw material source 2 is configured to supply the liquid film forming raw material R1 at a pressure that allows the liquid film forming raw material R1 to be introduced into the film forming raw material mixed gas generator 1 against its internal pressure. As a specific example, the film forming raw material source 2 can be configured to include a sealed container 21 that stores the liquid film forming raw material R1, and a pressurizing mechanism 22 that introduces pressurized gas that pressurizes the film forming raw material R1 into the head space in the sealed container 21.

[0033] The sealed container 21 may be configured to have a pipe connected thereto so that the film forming raw material R1 flows out from the bottom thereof. The pressurizing mechanism 22 may be configured to have a pressurized gas cylinder 221 that stores pressurized gas, and a pressurized gas adjusting valve 222 that adjusts the pressure of the pressurized gas supplied from the pressurized gas cylinder 221 to the sealed container 21. As the pressurized gas, it is preferable to use an inert gas such as helium gas.

[0034] The carrier gas source 3 can be configured to include a carrier gas cylinder 31 that stores carrier gas C, and a carrier gas adjustment valve 32 that adjusts the pressure of the carrier gas C supplied from the carrier gas cylinder 31 to the film forming raw material mixed gas generation apparatus 1.

[0035] The second raw material gas source 4 can be configured to include a second raw material gas cylinder 41 that stores the second raw material gas R2, and a second raw material gas adjustment valve 42 that adjusts the pressure of the second raw material gas R2 supplied from the second raw material gas cylinder 41 to the film forming raw material mixed gas generation apparatus 1.

[0036] The reaction chamber 5 accommodates a substrate on which a film is to be formed using a film-forming raw material mixed gas, and is configured so that the internal space can be evacuated. The reaction chamber 5 may have a known configuration including auxiliary equipment for film formation, such as a plasma generator.

[0037] As described above, the film forming apparatus 100 including the film forming raw material mixed gas generator 1 and the film forming apparatus 100 including the film forming raw material mixed gas generator 1 are provided with the auxiliary vaporizer 14, thereby capturing and vaporizing droplets of the film forming raw material R1 contained in the gas flowing out from the main vaporizer 13. This prevents droplets of the film forming raw material R1 from being introduced into the reaction chamber 5, thereby improving the quality of the film formation.

[0038] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. Furthermore, the effects described in the above-described embodiments are merely a list of the most preferable effects resulting from the present disclosure, and the effects of the present disclosure are not limited to those described in the above-described embodiments.

[0039] For example, in the film forming raw material mixed gas generation apparatus according to the present disclosure, the auxiliary heater 15, the outflow valve 16, and the second raw material gas supply unit 17 are optional components and may be omitted. Also, in the film forming raw material mixed gas generation apparatus 1 according to the present disclosure, the auxiliary vaporization unit 14 may be provided downstream of the junction of the outflow valve 16 and the second raw material gas supply unit 17. [Example]

[0040] Using the film formation apparatus shown in Figure 1, all gases were supplied to a reaction chamber with a wafer placed inside. The number of particles adhering to the wafer surface in the reaction chamber was then measured for each area. The same test was also performed using the same film formation apparatus, but with the porous vaporizing element of the auxiliary vaporizing unit removed. The porous vaporizing element used in the auxiliary vaporizing unit was a sintered compact of fibrous stainless steel, formed into a cylindrical shape with one end sealed.

[0041] Triethoxysilane was used as the film-forming raw material, and the supply rate of the film-forming raw material was 16.5 g / min. Argon gas was used as the carrier gas, and the supply rate of the carrier gas was 10 slm. Oxygen gas was used as the second raw material gas, and the supply rate of the second raw material gas was 40 slm. After supplying these mixed gases to the reaction chamber for 300 seconds, the particulate matter adhering to the wafer surface was counted. The counting results are shown in Table 1 below.

[0042] [Table 1]

[0043] As described above, it was confirmed that the use of a film-forming raw material mixed gas generator having an auxiliary vaporizer can vaporize the film-forming raw material and prevent the liquid film-forming raw material from being carried over into the reaction chamber. Furthermore, during maintenance after a long period of operation, it was confirmed that no liquid had accumulated in the porous vaporizer, meaning that all of the liquid film-forming raw material had been vaporized. [Explanation of symbols]

[0044] 1. Film-forming raw material mixed gas generator 2 Film-forming raw material source 3. Carrier gas source 4. Second raw gas source 5. Reaction Chamber 11 Film-forming raw material supply section 12 Carrier gas supply unit 13 Main vaporizer 14 Auxiliary vaporizer 15 Auxiliary heater 16 Outlet valve 17 Second raw material gas supply unit 100 Film deposition equipment 141 Porous vaporizer

Claims

1. a film-forming raw material supply unit that supplies a liquid film-forming raw material at a predetermined flow rate; a carrier gas supply unit that supplies a carrier gas at a predetermined flow rate; a main vaporization unit that vaporizes the film forming raw material by heating the film forming raw material supplied from the film forming raw material supply unit and the carrier gas supplied from the carrier gas supply unit; an auxiliary vaporization section having a porous vaporization member that captures droplets of the film-forming raw material carried over in the gas flowing out of the main vaporization section and vaporizes the captured droplets of the film-forming raw material; Equipped with the auxiliary vaporization unit vaporizes the liquid phase film forming raw material by heat of the gas phase film forming raw material and the carrier gas by retaining droplets of the film forming raw material; a saturated vapor pressure of the liquid of the film-forming source trapped in the auxiliary vaporizing section is higher than a vapor partial pressure of the film-forming source in the premixed gas passing through the auxiliary vaporizing section; the auxiliary vaporization unit has a flange for fixing the porous vaporization member in the flow path, the porous vaporization member is formed in a cylindrical shape with one end sealed and the other end connected to a flange, the porous vaporization member and the flange being made of metal, the auxiliary vaporization unit includes an auxiliary heater arranged to directly heat the auxiliary vaporization unit or to indirectly heat the auxiliary vaporization unit by heating a component in the vicinity of the auxiliary vaporization unit; The heating temperature of the auxiliary heater is 20° C. to 40° C. lower than the boiling point of the film-forming raw material mixed gas generating device.

2. 2. The film-forming raw material mixed gas generating apparatus according to claim 1, wherein the porous vaporizing member is made of a metal sintered body.

3. 3. The film-forming raw material mixed gas generating apparatus according to claim 2, wherein the metal sintered body is formed from a sintered body of a fibrous metal.

4. 2. The film-forming raw material mixed gas generating apparatus according to claim 1, wherein the auxiliary vaporizing section is disposed adjacent to the main vaporizing section.

5. 2. The film-forming raw material mixed gas generating apparatus according to claim 1, further comprising a second raw material gas supplying section that supplies a second raw material gas at a predetermined flow rate downstream of the auxiliary vaporizing section.

6. The film-forming raw material mixed gas generating apparatus according to claim 1 ; a reaction chamber to which the film-forming raw material and the carrier gas are supplied from the film-forming raw material mixed gas generator; A film forming apparatus comprising:

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