Film deposition raw material mixed gas generator and film deposition apparatus

Abstract

The present invention provides a film-forming raw material mixed gas generator and film-forming apparatus that can more reliably vaporize the film-forming raw materials. [Solution] A film-forming raw material mixed gas generating apparatus according to one aspect of the present invention comprises: a film-forming raw material supply unit that supplies liquid film-forming raw materials at a predetermined flow rate; a carrier gas supply unit that supplies carrier gas at a predetermined flow rate; a main vaporization unit that vaporizes the film-forming raw materials by heating the film-forming raw materials 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 having a porous vaporization member that captures droplets of the film-forming raw materials carried over into the gas flowing out from the main vaporization unit and vaporizes the captured droplets of the film-forming raw materials.

Description

Technical Field

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

Background Art

[0002] In the production of semiconductor devices and the like, a film-forming technique for forming a layer of a desired material on a substrate is widely used. For example, as a film-forming raw material containing atoms constituting at least a part of the material to be laminated on a semiconductor substrate, a material that is liquid at normal temperature and pressure may be used. Examples of such liquid film-forming raw materials include triethoxysilane (TEOS) used for forming a SiO2 insulating film. When using a liquid film-forming raw material, an apparatus for vaporizing the film-forming raw material and supplying it to a reaction chamber together with a carrier gas is required.

[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 each supplied quantitatively, the supplied film-forming raw material is vaporized and mixed with the carrier gas, and a mixed gas of the vaporized film-forming raw material and the carrier gas is supplied to a reaction chamber.

Summary of the Invention

Problems to be Solved by the Invention

[0004] When forming a film with a large thickness, in order to improve production efficiency, it is desirable to increase the supply amount of the film-forming raw material. However, when using a film-forming raw material that is liquid at normal temperature and pressure, if the supply amount of the film-forming raw material is increased, there is a possibility that the film-forming raw material cannot be sufficiently vaporized. If the vaporization of the film-forming raw material becomes insufficient, 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 deteriorate the quality of the formed film. Therefore, a film-forming raw material mixed gas generating apparatus and a film-forming apparatus that can more reliably vaporize the film-forming raw material are desired.

Means for Solving the Problems

[0005] A film-forming raw material mixed gas generating apparatus according to one aspect of the present disclosure comprises: a film-forming raw material supply unit that supplies liquid film-forming raw materials at a predetermined flow rate; a carrier gas supply unit that supplies carrier gas at a predetermined flow rate; a main vaporization unit that vaporizes the film-forming raw materials by heating the film-forming raw materials 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 having a porous vaporization member that captures droplets of the film-forming raw materials carried over into the gas flowing out from the main vaporization unit and vaporizes the captured droplets of the film-forming raw materials.

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

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

[0008] A film-forming raw material mixed gas generating apparatus according to one aspect of this disclosure may further include an auxiliary heater for heating the auxiliary vaporization section.

[0009] In a film-forming raw material mixed gas generating apparatus according to one aspect of the present disclosure, the auxiliary vaporization unit may be arranged adjacent to the main vaporization unit.

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

[0011] A film-forming apparatus according to another aspect of the present disclosure comprises any of the film-forming raw material mixed gas generators and 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. [Effects of the Invention]

[0012] A film-forming raw material mixed gas generator and film-forming apparatus according to one aspect of this disclosure can more reliably vaporize the film-forming raw material. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing the configuration of a film deposition apparatus according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0014] The embodiments of this disclosure will be described below with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of the film deposition apparatus 100.

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

[0016] The film-forming raw material mixed gas generator 1 comprises a film-forming raw material supply unit 11 that supplies liquid film-forming raw material R1 at a predetermined flow rate, a carrier gas supply unit 12 that supplies 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, and generates a pre-mixed gas Gp which is a mixed gas of the vaporized film-forming raw material R1 and carrier gas C, an auxiliary vaporization unit 14 that captures droplets of film-forming raw material R1 carried over into the pre-mixed gas Gp flowing out from the main vaporization unit and vaporizes the captured droplets of film-forming raw material R1, an auxiliary heater 15 that heats the auxiliary vaporization unit 14, an outlet valve 16 that can stop the outflow of the pre-mixed gas Gp, and a second raw material gas supply unit 17 provided downstream of the auxiliary vaporization unit 14 and that supplies a second 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. The film-forming raw material supply unit 11 can be configured to include a flow sensor and a flow control valve. The film-forming raw material R1 is selected according to the material of the film to be formed, but for example, triethoxysilane (TEOS) is used.

[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. The carrier gas supply unit 12 can be configured to include a flow sensor and a flow control valve. As the carrier gas C, an inert gas such as helium, argon, or nitrogen can be used.

[0019] The main vaporization unit 13 vaporizes the film-forming raw material R1 by heating the supplied film-forming raw material R1 and carrier gas C. For this reason, the main vaporization unit 13 can be configured to have a heat source such as an electric heater. Furthermore, it is preferable that the main vaporization unit 13 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 vaporization unit 13 is preferably above 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] Furthermore, the main vaporization unit 13 may be configured to generate a gas flow that can promote vaporization by shearing and subdividing the liquid film-forming raw material R1, such as a spiral gas, into the flow of the carrier gas C.

[0021] The auxiliary vaporization unit 14 includes a porous vaporization member 141 made of a porous body having pores through which droplets of the film-forming raw material R1 cannot pass. By capturing the droplets of the film-forming raw material R1 contained in the preliminary mixed gas Gp flowing out from the main vaporization unit 13, the porous vaporization member 141 prevents the droplets of the film-forming raw material R1 from being introduced into the reaction chamber 5. Further, the droplets of the film-forming raw material R1 captured by the porous vaporization member 141 penetrate into the porous vaporization member 141, thereby increasing the contact area with the preliminary mixed gas Gp passing through the porous vaporization member 141 and lengthening the residence time within the porous vaporization member 141, thus promoting vaporization.

[0022] The preliminary mixed gas Gp flowing out from the main vaporization unit 13 is considered to have sufficient thermal energy to vaporize the droplets of the film-forming raw material R1 contained therein by being heated in the main vaporization unit 13. Therefore, by retaining the droplets of the film-forming raw material R1 within the auxiliary vaporization unit 14, the liquid-phase film-forming raw material R1 can be vaporized by the heat possessed by the gaseous film-forming raw material R1 and the carrier gas.

[0023] Specifically, if the saturation vapor pressure of the liquid of the film-forming raw material R1 captured in the auxiliary vaporization unit 14 is higher than the vapor partial pressure of the film-forming raw material R1 in the preliminary mixed gas Gp passing through the auxiliary vaporization unit 14, the liquid of the film-forming raw material R1 captured in the auxiliary vaporization unit 14 can be vaporized. If the amount of the film-forming raw material R1 vaporized from the auxiliary vaporization unit 14 is larger than the amount of the liquid of the film-forming raw material R1 newly flowing out from the main vaporization unit 13, an equilibrium state can be obtained in which a film-forming raw material mixed gas Gm containing a predetermined amount of the film-forming raw material R1 is generated without blocking the auxiliary vaporization unit 14.

[0024] The porous body forming the porous vaporization member 141 of the auxiliary vaporization unit 14 is preferably a metal sintered body. By forming the porous vaporization member 141 with a metal sintered body, the thermal conductivity of the porous vaporization member 141 can be increased, so that heat can be transferred to the captured droplets of the film-forming raw material R1 and vaporized rapidly. The metal forming the porous vaporization member 141 is preferably a chemically stable metal such as stainless steel.

[0025] Further, the sintered metal body forming the porous vaporization member 141 is preferably a sintered body of fibrous metal. The sintered body of fibrous metal can increase the porosity while reducing the pore diameter. Thereby, while more reliably blocking the passage of the droplets of the film-forming raw material R1, the passage resistance of the premixed gas Gp can be reduced, and the captured film-forming raw material R1 can be rapidly vaporized. As the filtration accuracy of the porous vaporization member 141, it is desirable to be, for example, 0.5 μm or less. Further, by increasing the volume of the porous vaporization member 141, the vaporization capacity of the porous vaporization member 141 (the amount of the film-forming raw material R1 that can be vaporized per unit time) can be increased. Thus, since the vaporization capacity of the porous vaporization member 141 depends on various conditions, the specifications of the porous vaporization member 141 can be determined through experiments or actual operation.

[0026] The auxiliary vaporization unit 14 can be configured to have a flange 142 for fixing the porous vaporization member 141 in the flow path. The porous vaporization member 141 can be formed in a cylindrical shape with one end sealed and the flange 142 connected to the other end. By forming the porous vaporization member 141 and the flange 142 of metal, the heat of the auxiliary heater 15 can be conducted to the porous vaporization member 141 to rapidly vaporize the droplets of the captured film-forming raw material R1. Further, by configuring the auxiliary vaporization unit 14 to have a flange 142 provided at one end of the cylindrical porous vaporization member 141, the porous vaporization member 141 can be disposed inside the inlet flow path of the outflow valve 16 or the like to constitute the auxiliary vaporization unit 14. Thereby, since the auxiliary vaporization unit 14 does not require a dedicated housing, the film-forming raw material mixing gas generation device 1 can be miniaturized.

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

[0028] The auxiliary heater 15 is arranged to directly heat the auxiliary vaporization section 14, or to indirectly heat the auxiliary vaporization section 14 by heating components near the auxiliary vaporization section 14. As described above, the premixed gas Gp flowing from the main vaporization section 13 to the auxiliary vaporization section 14 has sufficient heat. Therefore, the heating temperature of the auxiliary heater 15 only needs to be high enough to suppress the temperature drop of the auxiliary vaporization section 14 due to heat dissipation into the atmosphere, and may be lower than the boiling point of the film-forming raw material. 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 premixed gas Gp or stop supplying premixed gas Gp, depending on the operating state of the reaction chamber 5. The outlet valve 16 can also be used to apply appropriate back pressure to the main vaporization section 13 to stabilize the vaporization of the film-forming raw material R1.

[0030] The second raw material gas supply unit 17 further adds the second raw material gas R2 to the premixed gas Gp flowing out from the outlet valve 16. This generates a film-forming raw material mixed gas Gm, which is a mixture of the premixed gas Gp and the second raw material gas R2. The film-forming raw material mixed gas generator 1 of this embodiment supplies the film-forming raw material mixed gas Gm thus generated to the reaction chamber 5.

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

[0032] The film-forming raw material source 2 is configured to supply liquid film-forming raw material R1 into the film-forming raw material mixed gas generator 1 at a pressure that can overcome its internal pressure. Specifically, the film-forming raw material source 2 can be configured to include a sealed container 21 for storing liquid-phase film-forming raw material R1 and a pressurizing mechanism 22 for introducing pressurized gas into the headspace of the sealed container 21 to pressurize the film-forming raw material R1.

[0033] The sealed container 21 can be configured such that piping is connected to allow the film-forming raw material R1 to flow out from its bottom. The pressurizing mechanism 22 can be configured to include a pressurized gas cylinder 221 for storing pressurized gas and a pressurized gas adjustment valve 222 for adjusting the pressure of the pressurized gas supplied from the pressurized gas cylinder 221 to the sealed container 21. It is preferable to use an inert gas such as helium gas as the pressurized gas.

[0034] The carrier gas source 3 can be configured to include a carrier gas cylinder 31 for storing carrier gas C and a carrier gas regulating valve 32 for adjusting the pressure of the carrier gas C supplied from the carrier gas cylinder 31 to the film-forming raw material mixed gas generator 1.

[0035] The second raw material gas source 4 can be configured to include a second raw material gas cylinder 41 for storing the second raw material gas R2, and a second raw material gas regulating valve 42 for adjusting 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 generator 1.

[0036] The reaction chamber 5 contains the substrate to be film-deposited using a film-depositing raw material mixed gas, and is configured to allow for vacuum evacuation of its internal space. The reaction chamber 5 can have a well-known configuration that includes auxiliary equipment for film deposition, such as a plasma generator.

[0037] As described above, the film-forming raw material mixed gas generator 1 and the film-forming apparatus 100 equipped with the film-forming raw material mixed gas generator 1 are equipped with an auxiliary vaporization unit 14, which captures and vaporizes droplets of the film-forming raw material R1 contained in the gas flowing out from the main vaporization unit 13. This prevents droplets of the film-forming raw material R1 from being introduced into the reaction chamber 5, thereby improving the film-forming quality.

[0038] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above. Furthermore, the effects described in the embodiments above are merely a list of the most preferred effects arising from this disclosure, and the effects of this disclosure are not limited to those described in the embodiments above.

[0039] For example, in the film-forming raw material mixed gas generator according to this disclosure, the auxiliary heater 15, the outlet valve 16, and the second raw material gas supply unit 17 are optional and may be omitted. Also, in the film-forming raw material mixed gas generator 1 according to this disclosure, the auxiliary vaporization unit 14 may be provided downstream of the confluence point of the outlet valve 16 and the second raw material gas supply unit 17. [Examples]

[0040] Using a film deposition apparatus with the configuration shown in Figure 1, all the gases were supplied to a reaction chamber in which a wafer was placed. The number of particles adhering to the wafer surface inside the reaction chamber was then measured in different ranges. The same test was also performed using the same film deposition apparatus with the porous vaporization member of the auxiliary vaporization section removed. The porous vaporization member of the auxiliary vaporization section was made of a sintered body of fibrous stainless steel and was 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 raw material was set to 16.5 g / min. Argon gas was used as the carrier gas, and the supply rate of the carrier gas was set to 10 slm. Oxygen gas was used as the second raw material gas, and the supply rate of the second raw material gas was set to 40 slm. After supplying these mixed gases to the reaction chamber for 300 seconds, the granular material adhering to the wafer surface was counted. The counting results are shown in Table 1.

[0042] [Table 1]

[0043] As described above, it was confirmed that by using a film-forming raw material mixed gas generator with an auxiliary vaporization unit, the film-forming raw material can be vaporized, preventing the liquid phase of the film-forming raw material from being carried over into the reaction chamber. Furthermore, during maintenance after long-term operation, it was confirmed that no liquid had accumulated in the porous vaporization member, 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 material gas source 5. Reaction Chamber 11 Film-forming raw material supply section 12. Carrier Gas Supply Section 13 Main vaporization section 14. Auxiliary vaporization unit 15. Auxiliary heater 16 Outlet valve 17. Second Raw Material Gas Supply Department 100 Film deposition equipment 141 Porous vaporizing member

Claims

1. A film-forming raw material supply unit that supplies liquid film-forming raw materials at a predetermined flow rate, A carrier gas supply unit that supplies 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 unit having a porous vaporizing member that captures droplets of the film-forming raw material carried over into the gas flowing out from the main vaporization unit and vaporizes the captured droplets of the film-forming raw material, A film-forming raw material mixed gas generating apparatus equipped with the following features.

2. The porous vaporizing member is formed from a metal sintered body, as described in claim 1, for the film-forming raw material mixed gas generating apparatus.

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 fibrous metal.

4. The film-forming raw material mixed gas generating apparatus according to claim 1, further comprising an auxiliary heater for heating the auxiliary vaporization section.

5. The film-forming raw material mixed gas generating apparatus according to claim 1, wherein the auxiliary vaporization unit is disposed adjacent to the main vaporization unit.

6. The film-forming raw material mixed gas generating apparatus according to claim 1, further comprising a second raw material gas supply unit that supplies a second raw material gas at a predetermined flow rate downstream of the auxiliary vaporization unit.

7. A film-forming raw material mixed gas generating apparatus according to claim 1, A reaction chamber supplied with the film-forming raw material and the carrier gas from the film-forming raw material mixed gas generator, A film deposition apparatus equipped with the following features.

Images