JP3893177B2 - Vaporizer, CVD apparatus, and thin film manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a thin film forming apparatus for forming various thin films using a chemical vapor deposition (hereinafter abbreviated as CVD) method, in particular, a vaporizing apparatus for vaporizing a liquid material and supplying the thin film forming apparatus to the thin film forming apparatus. The present invention relates to a CVD apparatus using the apparatus.
[0002]
[Prior art]
  In recent years, high density and high integration of semiconductor devices have shown rapid progress. For example, the degree of integration of semiconductor devices represented by dynamic random access memory (= DRAM) is steadily increasing. However, the amount of charge stored in each cell in the DRAM needs to be maintained at a substantially constant value regardless of the degree of integration. In conventional DRAMs, the amount of charge was maintained at a constant value by reducing the thickness of the silicon oxide film, which is a capacitor film. However, as thinning is approaching its limit, capacity can be secured by a different approach. It was necessary to do it. As a countermeasure, there is a movement to use a high dielectric constant material for the capacitor film. For example, tantalum oxide having a relative dielectric constant of about 25 is likely to be used in a 1 Gbit DRAM. For DRAMs exceeding 1 Gbit, barium strontium titanate (= BST) or zirconate titanate having a relative dielectric constant of several hundreds or more. The use of lead acid (= PZT) is considered promising.
[0003]
  In general, in order to form a BST or PZT capacitor film on a capacitor electrode having a stepped portion on a DRAM substrate, it is most effective to use a CVD method with good coverage. Previously, BST and PZT source gases were obtained by sublimating metal complex materials coordinated with β-diketone dipivaloylmethane (= DPM) or the like. In recent years, in order to stably supply the source gas, a method of obtaining the source gas by dissolving these metal complex materials in a solvent and evaporating the solution is becoming mainstream.
[0004]
  As an example of such a conventional solution vaporization type CVD apparatus, there is a CVD apparatus disclosed in JP-A-7-94426.
[0005]
  A conventional solution vaporization type CVD apparatus will be described below with reference to the drawings.
[0006]
  FIG. 6 is a cross-sectional view of a conventional CVD apparatus. As shown in FIG. 6, the present CVD apparatus is roughly divided into a vaporizer 101 that generates a vaporized raw material and a reaction furnace 150 that heats and reacts the vaporized raw material supplied from the vaporizer 101.
[0007]
  A vaporizer 101 having a vaporization chamber 102 for vaporizing a liquid raw material is embedded with a heater 103 for heating the vaporizer 101 to a predetermined temperature inside a wall material around the vaporization chamber 102. Furthermore, the vaporizer 101 has a tapered shape having a tapered constricted portion 104a at its tip for allowing the dilution gas for conveying the vaporized raw material generated in the vaporization chamber 102 to the reaction furnace 150 to flow into the vaporization chamber 102 at high speed. The thin tube 104 is connected to a raw material gas transport pipe 105 that supplies the vaporized raw material generated in the vaporization chamber 102 to the reaction furnace 150. A filter 106 is provided near the opening of the source gas transport pipe 105 in the vaporization chamber 102 to filter out foreign matters mixed in the vaporized source. Around the source gas transport pipe 105, a heat retaining heater 107 that is kept at a predetermined temperature is provided in a spiral shape at a predetermined interval in order to prevent recondensation of the vaporized raw material caused by lowering the temperature below the predetermined temperature. .
[0008]
  The upstream end of the tapered capillary 104 is connected to a dilution gas supply 110 that adjusts the flow rate of the dilution gas. In addition, a liquid source supply pipe 111 that supplies a liquid source to the vaporizing chamber 102 is provided inside the tapered capillary 104 so as to extend in the axial direction at the center of the tapered capillary 104. The downstream end of the liquid source supply pipe 111 is opened as a nozzle 111 a at the downstream end of the constricted portion 104 a of the tapered narrow tube 104, and the upstream end of the liquid source supply pipe 111 is tapered in the vicinity of the upstream end of the tapered narrow tube 104. The thin tubule 104 is bent outward in the radial direction, penetrates the side surface of the tapered tubule 104 from the inside to the outside, and is connected to a liquid source supplier 112 that adjusts the flow rate of the liquid source. The upstream side of the liquid source supply unit 112 is connected to a source container 113 that stores the liquid source. Connected to the upper part of the raw material container 113 is a pressurized gas pipe 114 for pumping the liquid raw material to the liquid raw material supplier 112.
[0009]
  A substrate holding table 152 for holding the substrate 151 is provided inside the reaction furnace 150, a reaction furnace heating means 153 for heating the reaction path 150 is provided on the side wall of the reaction furnace 150, and an upper part of the reaction furnace 150 is provided at the top. A reaction gas transport pipe for supplying a reaction gas to be reacted with the vaporized raw material into the reaction furnace 150 is provided.
[0010]
  The operation of the conventional CVD apparatus configured as described above will be described below.
[0011]
  First, the liquid raw material in the raw material container 113 is pressurized by the pressurized gas sent through the pressurized gas pipe 114, and after the flow rate of the pressurized liquid raw material is adjusted by the liquid raw material supplier 112. Then, the liquid is supplied to the tip of the nozzle 111a through the liquid source supply pipe 111.
[0012]
  On the other hand, the dilution gas whose flow rate is adjusted by the dilution gas supply device 110 is sent to the tapered narrow tube 104, and the dilution gas increases the flow velocity at the throttle portion 104 a at the tip of the tapered narrow tube 104. As a result, the liquid raw material exiting from the tip of the nozzle 111 a by the diluting gas having a high flow velocity becomes fine droplets and is injected into the vaporizing chamber 102 of the vaporizer 101. Since the vaporizer 101 is heated to, for example, 200 ° C. by the heater 103, the liquid raw material composed of the ejected droplets touches the inner wall of the vaporizing chamber 102 or vaporizes by radiant heat on the inner wall. The vaporized raw material gas passes through the filter 106 and is supplied to the reaction furnace 150 through the raw material gas transport pipe 105 which is kept warm by a heat retaining heater 107 which prevents recondensation.
[0013]
  The filter 106 is provided for re-evaporating or trapping liquid raw material particles that have not sufficiently evaporated in the vaporization chamber 102 and solidified particles. The side wall of the reaction furnace 105 is also set to a predetermined temperature by the reaction furnace heating means 153 that prevents the vaporized raw material from condensing. Further, for example, oxygen gas as an oxidant is supplied to the reaction furnace 150 through a reaction gas transport pipe 154 that is a separate system from the source gas transport pipe 105. As a result, when the substrate 151 to be deposited is placed on the substrate holding surface of the substrate holding table 152 and the temperature of the substrate 151 is raised above the source gas decomposition temperature, the source gas is decomposed and oxidized on the surface of the substrate 151. Since the process proceeds simultaneously, an oxide thin film is formed on the surface of the substrate 151.
[0014]
[Problems to be solved by the invention]
  However, since the conventional CVD apparatus supplies the liquid source to the liquid source supply pipe 111 and its nozzle 111a to make the liquid source into fine droplets, it remains in the pipe leading to the nozzle 111a when the apparatus is stopped. It is necessary to prevent clogging due to deterioration and precipitation of the liquid raw material. Therefore, it is necessary to go through a procedure to remove the residual liquid raw material every time the equipment is stopped, which not only complicates the operation of the equipment, but also requires a dedicated pipe for removing clogging, making the equipment configuration complicated. Had the problem of becoming.
[0015]
  In addition, there is a limit to atomization of the liquid raw material by the vaporizer 101, and on the principle that droplets are generated from the liquid that comes out of the narrow tube by a high-speed air stream, droplets having a relatively large diameter are generated. The raw materials that were used had to be non-uniform. For this reason, while the liquid raw material which does not fully vaporize but passes through the vaporizer exists, on the contrary, the solid component is precipitated by being overheated. In order to cope with this, a filter 106 is provided to remove these liquid raw materials and solid components. However, since the filter 106 is provided, it is necessary to periodically replace the filter 106, and the apparatus cannot be operated continuously. Had the problem. Further, since the flow rate of the vaporized raw material passing through the filter 106 changes depending on the operation status of the filter 106, as a result, the supply amount of the vaporized raw material changes over time. The part which relies on experience became large and had the problem that it could not be used as a general-purpose CVD apparatus.
[0016]
  An object of the present invention is to solve the above-mentioned conventional problems all at once, to enable generation of a stable vaporization raw material that does not change with time, and to enable general-purpose and high-quality film formation.
[0017]
[Means for solving the problems]
  Achieve the above objectivesThe vaporizer according to the present invention is
  A liquid material container for storing the liquid material;
  An ultrasonic oscillator that is provided in the liquid raw material container and generates liquid droplets on the liquid surface from the liquid raw material by vibrating the liquid surface of the liquid raw material with ultrasonic waves;
A transport gas supply pipe for supplying a transport gas mixed with the liquid droplets to transport the liquid droplets into the liquid source container;
  A vaporized raw material transport pipe for transporting the generated vaporized raw material while generating the vaporized raw material by heating and vaporizing with the heating means while transporting the droplet mixed with the transport gas in the liquid raw material container A vaporizing device comprising:
  It is further characterized by further comprising a mixing preventing means provided inside the vaporized raw material transport pipe and preventing the droplets adhering to the inner wall surface of the vaporized raw material transport pipe from mixing into the liquid raw material.
[0018]
  The mixing preventing means is provided in the enlarged portion in which the inner diameter of the vaporized raw material transport pipe is partially enlarged, and the enlarged portion is provided with an apex located in the transport direction and a peripheral end portion in the enlarged portion. It is preferable to have a conical body located outside the inner wall surface of the raw material transport pipe.
[0019]
  It is preferable that the apparatus further includes a cooling unit that cools the droplets so that the droplets transported in the vaporized raw material transport pipe are not vaporized before being heated by the heating unit.
[0020]
  The cooling means preferably cools the droplets to about room temperature.
[0021]
  Achieve the above objectivesThe CVD apparatus according to the present invention is the above-mentionedA vaporizer;
  A reaction furnace connected to the discharge side of the vaporized raw material transport pipe of the vaporizer and reacting by heating the vaporized raw material transported by the vaporized raw material transport pipe;
  A substrate holder that is provided inside the reactor and holds the substrate;
  Provided in the reactor, the reactionFurnaceAnd a reactor heating means for heating the reactor.
[0022]
  It is preferable that the substrate holder has substrate heating means for heating the substrate to a predetermined temperature.
[0023]
  It is preferable to further include a reaction gas supply pipe for supplying a reaction gas that reacts with the vaporized raw material into the reaction furnace.
[0024]
  The reaction gas supplied from the reaction gas supply pipe is O.₂, NO, N₂O and O_ThreePreferably, at least one of these is included.
[0025]
  Achieve the above objectivesThe thin film manufacturing method according to the present invention includes the above-described method.A vaporized raw material is generated from a liquid raw material by a vaporizer, and the vaporized raw material is decomposed on the surface of a substrate installed in a reaction furnace and brought to a temperature higher than the temperature at which the vaporized raw material decomposes, and a thin film is deposited on the substrate. It is characterized by.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
  (First reference form)
  Of the present inventionFirst reference formWill be described with reference to the drawings.
[0027]
  FIG. 1 illustrates the present invention.First reference form1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer. As shown in FIG. 1, the CVD apparatus 1 includes a vaporizer 10A that generates a vaporized raw material obtained by vaporizing a liquid raw material, and a reaction furnace 50 that heats and reacts the vaporized raw material. The vaporizer 10A includes a liquid raw material container 12 that stores a liquid raw material 11 that is a film forming raw material, and a vaporizer 14 that generates the vaporized raw material 13 from the liquid raw material 11 by heating and vaporizing the liquid raw material 11. ing. An ultrasonic oscillator 17 that generates fine liquid droplets 16 from the liquid material 11 on the liquid surface of the liquid material 11 by vibrating the liquid surface of the liquid material 11 with the ultrasonic wave 15 is provided at the bottom of the bottom surface of the liquid material container 12. Is provided. In the upper part of the liquid source container 12, a transport gas supply pipe 19 for supplying a transport gas 18 made of an inert gas, for example, argon, mixed with the droplets 16 and transported to the reaction furnace 50, and An unloading tube 20 is provided as a part of the vaporized material conveying tube for unloading the conveying gas 18 mixed with the droplets 16 from the liquid material container 12. The vaporizer 14 has a cylindrical shape that is smoothly connected to the opening end on the carry-out side of the carry-out tube 20, and a heating means 21 that vaporizes the droplets 16 that circulate inside the vaporizer 14 is provided on the outer peripheral surface thereof. It has been. In addition, as shown in the figure, the diameter of the vaporizer 14 may be made larger than the diameter of the carry-out pipe 20, and the droplet 16 may be sufficiently heated by suppressing the flow velocity of the carrier gas 18. Further, the vaporizer 14 may be formed integrally with the carry-out pipe 20 by providing the heating means 21 on a part of the outer circumference or the inner circumference of the carry-out pipe 20. A vaporized raw material transport pipe 22 for transporting the vaporized raw material 13 vaporized by the vaporizer 14 to the reaction furnace 50 is smoothly connected to the vaporizer 14 at the opening end on the carry-out side of the vaporizer 14. The open end on the carry-out side of the vaporized raw material transfer pipe 22 is connected to the upper part of the reaction furnace 50. A heat retaining heater 23 as a heat retaining means for preventing the vaporized raw material 13 from being cooled and re-liquefied (= condensed) is attached to the outer peripheral portion of the vaporized raw material transport pipe 22.
[0028]
  The reaction furnace 50 is provided with a reaction chamber 51 therein. An upper end of the reaction chamber 51 is connected to an opening end on the carry-out side of the vaporized raw material transport pipe 22, and the front end portion of the vaporized raw material is introduced in a divergent shape. A part 52 is provided. A reaction furnace heating means 53 for adjusting the temperature of the wall surface of the reaction path 50 is provided on the outer wall surface of the reaction furnace 50 in order to prevent recondensation of the vaporized raw material supplied from the vaporizer 10A. At the bottom of the reaction chamber 51, a substrate holding base 55 for holding a substrate 54 made of, for example, silicon, is installed on the substrate holding surface. A sheath resistance heater 56 is disposed as a substrate heating means for heating to a temperature. Further, a reaction gas supply pipe 58 for supplying a reaction gas 57 that reacts with the vaporized raw material to the reaction chamber 51 is provided at the upper part of the reaction chamber 51, and an exhaust means 59 that exhausts the reaction chamber 51 from the bottom of the reaction chamber 51. Are connected through an exhaust pipe.
[0029]
  Hereinafter, operations of the vaporization apparatus 10A and the CVD apparatus 1 configured as described above will be described. First, in the liquid source container 12, for example, Ba (DPM)₂ , Sr (DPM)₂ And TiO (DPM)₂ Is stored in THF (tetrahydrofuran) at a molar ratio of 1: 1: 2 and a total concentration of 0.1 mol / l. An ultrasonic oscillator 17 is provided in close contact with the bottom of the liquid raw material container 12 and oscillates the ultrasonic waves 15 toward the liquid surface of the liquid raw material 11. The ultrasonic wave 15 propagates through the liquid raw material 11, reaches the liquid surface of the liquid raw material 11, and generates ultrasonic vibrations on the liquid surface of the liquid raw material 11. The liquid raw material 11 has a viscosity as a liquid and not only vibrates but also exerts an inertial force on the liquid itself due to the vibration of the liquid surface. The liquid droplet 16 is discharged into the space above the liquid source container 12.
[0030]
  The ultrasonic oscillator 17 is provided outside the bottom of the liquid source container 12, but is not limited thereto, and may be on the bottom surface in the liquid source container 12. Further, the liquid source container 12 is not limited to the bottom portion, and may be a side portion.
[0031]
  Next, the carrier gas 18 is supplied to the liquid source container 11 through the carrier gas supply pipe 19, and a large number of droplets 16 discharged into the space above the liquid source container 12 are transferred to the carrier gas 18. The mixed gas is mixed to form a mixed gas, which is unloaded from the unloading pipe 20 of the liquid source container 12 and carried to the vaporizer 14. The vaporizer 14 is a raw material Ba (DPM) in which the droplets 16 are vaporized and dissolved by the heating means 21.₂ , Sr (DPM)₂ And TiO (DPM)₂ Is set to a temperature at which no decomposition occurs, for example, 250 ° C., and the droplet 16 is heated and vaporized to become the vaporized raw material 13.
[0032]
  In the conventional nozzle injection method, there is a limit to atomization of the liquid raw material, and the droplet diameter is about several tens of μm at the minimum.referenceIn the form, it is possible to obtain extremely fine droplets 16 having an average particle diameter of about several μm. Therefore, the temperature and vaporization of the droplet 16 are performed at high speed, and an ultrafine liquid material can be obtained by a simple principle. Therefore, if the viscosity of the liquid material is stable, the droplet can be generated with the intensity of ultrasonic waves. The supply amount of 16 can be controlled. Therefore, since the reproducibility of the particle size is also high, a stable vaporized raw material can be supplied.
[0033]
  Next, the vaporized raw material 13 is transported through the vaporized raw material transport pipe 22 together with the transport gas 18 and supplied to the reaction furnace 50. Since the vaporized raw material transport pipe 22 is kept at, for example, 200 ° C. by the heat retaining heater 23 attached to the vaporized raw material transport pipe 22, the vaporized raw material 13 is maintained in a good vaporized state without being reliquefied. It is introduced into the reaction chamber 51 from the vaporized raw material introduction part 52 of the reaction furnace 50. The temperature of the reaction chamber 50 is controlled, for example, by a reaction furnace heating means 53 that circulates oil set to 200 ° C., and the vaporized raw material 13 is liquefied in the reaction chamber 51. It is preventing. On the other hand, a reaction gas 57 such as oxygen gas is supplied from the reaction gas supply pipe 58 to the reaction furnace 50 and reaches the surface of the substrate 54 placed on the substrate holding portion of the substrate holding table 55 together with the vaporized raw material 13. . The substrate 54 is heated and heated by a sheath resistance heater 56 disposed in the substrate holding portion of the substrate holding table 55.
[0034]
  The temperature of the substrate 54 is an important parameter that greatly affects the crystal state of the film to be deposited.referenceIn the embodiment, a BST film having a small particle size is formed by setting the temperature to 430 ° C., for example. Unreacted vaporized raw material 13, reaction gas 57, unnecessary gas generated by the reaction, and the like are exhausted to the outside from the bottom of reaction chamber 51 through exhaust means 59.
[0035]
  As explained above, the bookreferenceAccording to the embodiment, since the liquid droplets 16 are generated by ultrasonically vibrating the liquid surface of the liquid raw material 11, unlike the conventional sprayer, it is possible to generate a liquid raw material with a very fine particle size. . As a result, since a favorable vaporization state can be realized, maintenance such as clogging of the pipe at the nozzle portion and replacement of the filter is not required as in the prior art.
[0036]
  Accordingly, since the supply amount of the atomized liquid raw material, that is, the droplet 16 does not change with time, it is possible to supply the vaporized raw material stably over a long period of time. According to the CVD apparatus 1 using the vaporizer 10A, the composition and The reproducibility of the film formation rate becomes very good.
[0037]
  BookreferenceIn the embodiment, the reaction gas 57 made of oxygen gas is supplied to the reaction chamber 51. However, if the reaction gas 57 is not particularly required, the reaction gas supply pipe 58 may be omitted.
[0038]
  Also bookreferenceThe form is not limited to the type of film to be formed, and film formation is possible as long as the liquid raw material or the solution raw material has a raw material obtained at a decomposition temperature or lower.
[0039]
  Further, in order to form a film composed of a plurality of elements, these raw materials are individually dissolved using the liquid raw material containers 12, 12,... Corresponding to the number of liquid raw materials provided with the ultrasonic transmitters 17, respectively. The liquid raw materials 11, 11, ... may be atomized and then mixed and vaporized. Incidentally, it can be easily analogized that this mixing process may be performed after vaporization.
[0040]
  Also bookReference formAnd each embodiment described below・ Reference formHowever, the material of the film to be formed is only an example, and it goes without saying that the film of other materials can be formed in the same manner as long as the liquid raw material 11 can be obtained.
[0041]
  (First embodiment)
  Hereinafter, the present inventionFirst embodimentWill be described with reference to the drawings.
[0042]
  FIG. 2 illustrates the present invention.First embodiment1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer. As shown in FIG. 2, the CVD apparatus 1 includes a vaporizer 10B that generates a vaporized raw material obtained by vaporizing a liquid raw material and a reaction furnace 50 that heats and reacts the vaporized raw material. In addition, the CVD apparatus 1 of this embodiment isFirst reference formSince only the vaporizer 10B is different from the CVD apparatus 1 ofFirst reference formThe same members as those in FIG. As shown in FIG. 2, on the carry-in side of the vaporizer 14 in the carry-out pipe 20, an enlarged part 31 in which the inner diameter of the carry-out pipe 20 is partially enlarged, and the apex is located in the enlarged part 31 in the carrying direction. An anti-mixing means having a conical body 30 is provided. The peripheral end portion of the conical body 30 is provided so as to be located outside the inner wall surface of the carry-out tube 20 in the enlarged portion 31, and unnecessary droplets 16a adhering to the inner wall surface of the carry-out tube 20 fall. Mixing into the liquid raw material 11 can be reliably prevented. Unnecessary droplets 16 a that have dropped onto the upper surface of the cone 30 are once stored in a tray provided in the enlargement unit 31, and the droplets 16 a that have accumulated in the tray pass through a discharge pipe 32 provided in the enlargement unit 31. It is discharged outside.
[0043]
  In the present embodiment, the carry-out pipe 20 is connected so as to extend perpendicularly to the liquid surface of the liquid source container 12, but the present invention is not necessarily limited to this, and the horizontal direction relative to the liquid surface. You may connect so that it may extend. However, when the carry-out tube 20 extends in the horizontal direction, the conical body 30 is not necessarily required, but traps the unnecessary liquid droplets 16a adhering to the inner wall surface of the carry-out tube 20 so as not to flow back to the liquid source container 12. For example, it is preferable that a trap part such as the enlarged part 31 and a discharge pipe 32 for discharging the unnecessary liquid droplets 16a accumulated in the trap part to the outside of the carry-out pipe 20 are provided.
[0044]
  Further, between the conical body 30 and the vaporizer 14 having the heating means 21, the cooling water 34A and 34B for preventing the temperature rise of the carry-out pipe 20 is circulated therein so that the temperature of the carry-out pipe 20 is set to a predetermined temperature. The cooling means 33 for keeping the temperature is provided on the outer peripheral portion of the carry-out pipe 20. The set temperature of the cooling means 33 may be a temperature at which the droplets 16 are not decomposed, for example, 200 ° C. or less.
[0045]
  Note that the mixing prevention unit and the cooling unit 33 do not necessarily include both, and may include either one.
[0046]
  Hereinafter, operations of the vaporization apparatus 10B and the CVD apparatus 1 configured as described above will be described.First reference formIn the vaporizer 10 </ b> A, when unnecessary droplets 16 a adhere to the inner wall of the carry-out tube 20, it is conceivable that these droplets 16 a flow backward into the liquid source container 12 and mix into the liquid source 11. If the liquid raw material 11 is a material that is easily altered, when the unnecessary droplets 16a are mixed into the liquid raw material 11, the component ratio of the unnecessary liquid droplets 16a to the solvent changes compared to the component ratio of the liquid raw material 11 to the solvent. Therefore, there is a possibility that the quality of the liquid raw material 11 is deteriorated and the quality of the film formed is deteriorated or the supply is unstable.
[0047]
  Therefore, the vaporizer 10 </ b> B of the present embodiment is provided with the conical body 30 inside the carry-out pipe 20 so that unnecessary droplets 16 a do not flow into the liquid source container 12. The droplets 16a adhering to the conical body 30 and the carry-out tube 20 fall due to gravity and are received by the enlarged portion 31 to become discharged liquid. The discharged liquid is discharged to the outside through the discharge pipe 32.
[0048]
  In addition, when the discharged liquid does not change in quality, it goes without saying that the discharged liquid can be reused as the liquid raw material 11, and efficient use can be achieved.
[0049]
  On the other hand, according to the vaporization principle of the present vaporizer 10B, a very fine liquid raw material can be obtained by vibrating the liquid surface of the liquid raw material 11 using ultrasonic waves, so that a uniform and good vaporized raw material can be obtained.First reference formAs explained in. However, since the liquid raw material 11 is still under development and is not perfect, it is conceivable that solid matter deposited from the liquid raw material 11 adheres to the inner wall surface of the carry-out pipe 20 depending on long-term use.First reference formIn the vaporizer 10 </ b> A, when the vaporizer 14 is heated using the heating means 21, the heat of the heating means 21 is transmitted to the carry-out pipe 20 by heat conduction, and thus the temperature of the carry-out pipe 20 increases. As a result, it is conceivable that the solid matter deposited from the liquid raw material 11 adheres to the inner wall surface of the carry-out tube 20 and it takes time to clean the solid matter and replace the carry-out tube 20.
[0050]
  In this embodiment, the temperature rise of the carry-out pipe 20 is prevented by providing the cooling means 33 for cooling the carry-out pipe 20 with the cooling water 34A, 34B in the vicinity of the vaporizer 14 of the carry-out pipe 20. As a result, solid matter does not adhere to the inner wall surface of the carry-out tube 20, and the solid matter adheres only to the vaporizer 14, and the CVD apparatus 1 can be operated simply by cleaning or replacing the vaporizer 14. Is possible.
[0051]
  The mixing prevention means also has an effect of preventing the solid matter generated in the vaporizer 14 from falling into the liquid raw material container 12.
[0052]
  Thus, according to the vaporizer 10B according to the present embodiment, unnecessary liquid droplets 16a that adhere to the carry-out pipe 20 and fall and mix into the liquid raw material container 12 can be prevented by the mixing prevention means. Even when 11 is easily altered, the vaporized raw material 13 having a stable quality can be supplied to the reaction furnace 50.
[0053]
  Moreover, since the cooling means 33 is provided in the vicinity of the connection part of the unloading pipe 20 between the unloading pipe 20 and the vaporizer 14, the temperature rise of the unloading pipe 20 is suppressed. From this, it is possible to prevent the solid matter from depositing and adhering, and to facilitate the operation of the CVD apparatus 1.
[0054]
  In addition, although the cooling means 33 used the system which circulates the cooling water 33A and 33B, you may cool using not only this but another method, such as sticking a Peltier element to the carrying-out pipe 20, for example.
[0055]
  (Second reference form)
  Hereinafter, the present inventionSecond reference formWill be described with reference to the drawings.
[0056]
  FIG. 3 illustrates the present invention.Second reference form1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer. In FIG. 3, the same members as those shown in FIG. As shown in FIG.referenceInside the reaction furnace 50 according to the embodiment, a vaporized raw material generating part 51A is provided at the upper part, and a reaction chamber 51B as a film forming part partitioned from the vaporized raw material generating part 51A by a partition plate is provided at the lower part. Yes.
[0057]
  A vaporizer 10C is disposed inside the vaporized raw material generator 51A, and the vaporizer 10C is atomized as a droplet generator having an ultrasonic transmitter 62 provided to be in close contact with the outside of the bottom. The vaporization raw material production | generation means which produces | generates the vaporization raw material 13 from the liquid raw material 11 by connecting the chamber 61 and this atomization chamber 61 by piping, and heating and vaporizing the droplet 16 produced | generated in the atomization chamber 61. The carburetor 14 is configured. A liquid raw material supply pipe 63 is connected to the introduction side of the atomizing chamber 61, and the atomizing chamber 61 is connected to a liquid raw material container via a liquid raw material supply pipe 63 and a liquid raw material supply device 64 made of, for example, a liquid pump. 12 is connected. Further, in the vicinity of the opening on the introduction side of the liquid source supply pipe 63 in the upper part of the atomizing chamber 61, an inert gas, for example, argon, mixed with the droplets 16 and transported to the reaction chamber 51B. A transfer gas supply pipe 19 for supplying the transfer gas 18 is provided.
[0058]
  In the liquid source container 12, for example, TiO (DPM)₂ The liquid raw material 11 which melt | dissolved in THF is accommodated.
[0059]
  Hereinafter, operations of the vaporization apparatus 10C and the CVD apparatus configured as described above will be described. The liquid raw material 11 in the liquid raw material container 12 is supplied to the atomizing chamber 61 through the liquid raw material supply pipe 63 with the flow rate adjusted by the liquid raw material supply device 64. The ultrasonic oscillator 62 provided outside the bottom of the atomization chamber 61 emits ultrasonic waves, and the liquid material 11 supplied to the atomization chamber 61 touches the bottom surface of the atomization chamber 61 that vibrates ultrasonically. By the abovereferenceSimilar to the form, the liquid raw material 11 is atomized to generate droplets 16. The droplets 16 made of the liquid raw material 11 are mixed with the transport gas 18 supplied from the transport gas supply pipe 19 and transported to the vaporizer 14, and then heated by the heating means 21 provided on the outer peripheral surface of the vaporizer 14. The vaporized raw material 13 is heated and vaporized. The vaporized raw material 13 generated in the vaporizer 14 passes through the vaporized raw material transport pipe 22 and the vaporized raw material introduction part 52 provided in the upper part of the reaction chamber 51B, and is an upper surface of a substrate 54 made of, for example, silicon. To be supplied.
[0060]
  Like thisreferenceAccording to the form, the inside of the reaction furnace 50 is divided into a vaporized raw material generating part 51A and a reaction chamber 51B as a film forming part, and the liquid raw material 11 is supplied into the reaction furnace 50 from the outside, so the vaporizer 10C is small. Therefore, the degree of freedom in arranging the CVD apparatus is improved.
[0061]
  Further, the vaporized raw material generating part 51A is arranged inside the reaction furnace 50, and the vaporized raw material generating part 51A is kept warm by the reaction furnace heating means 53 so that the temperature becomes 200 ° C., for example. As a result, the firstReference formOrFirst embodimentIt is possible to eliminate the need for the heat retaining heater 23 for retaining the vaporized raw material transport pipe 22 shown in FIG.
[0062]
  In general, the vaporized raw material gas 13 requires strict temperature control.referenceBy controlling the temperature collectively in the reaction furnace 50 as in the embodiment, the device structure can be simplified and the controllability can be improved.
[0063]
  Like thisreferenceAccording to the vaporization apparatus 10C according to the embodiment, the liquid raw material 11 is supplied from the outside, thereby reducing the size of the apparatus and improving the degree of freedom in arrangement. Furthermore, in the CVD apparatus using the present vaporizer, by arranging the vaporizer 10C in the temperature-controlled reaction furnace 50, the temperature of the vaporized raw material 13 can be easily controlled and the structure of the CVD apparatus is simplified. be able to.
[0064]
  In order to prevent the liquid material 11 from boiling near the entrance of the atomization chamber 61 as the temperature of the liquid material supply tube 63 rises, a cooling means is provided in the vicinity of the carry-in portion of the atomization chamber 61 in the liquid material supply tube 63. May be provided.
[0065]
  In addition, although the ultrasonic transmitter 62 is provided outside the bottom of the atomization chamber 61, the present invention is not limited to this and may be on the bottom surface in the atomization chamber 61.
[0066]
  (Third reference form)
  Hereinafter, the present inventionThird reference formWill be described with reference to the drawings.
[0067]
  FIG. 4 illustrates the present invention.Third reference formIt is a composition sectional view of the vaporizer concerning. In FIG. 4, the same members as those shown in FIG. The vaporizer 10D shown in FIG. 4 is configured integrally with a vaporizer 10C including an atomization chamber 61 and a vaporizer 14 arranged in a vaporized raw material generator 51A in which the inside of the reaction furnace 50 shown in FIG. 3 is partitioned. Has been. The vaporization apparatus 10D is provided with a vaporization chamber 65 formed of a single space inside thereof, and an ultrasonic oscillator 62 that generates a fine liquid raw material from the liquid raw material 11 is provided outside the bottom thereof. On the carry-in side of the vaporizer 10D, a liquid raw material supply pipe 63 that supplies the liquid raw material 11 in a liquid raw material container (not shown) to the vaporizer 10D and the vaporized raw material 13 mixed with the vaporized raw material 13 are not shown. A transfer gas supply pipe 19 for supplying the transfer gas 18 transferred to the reaction chamber is connected independently. On the outer peripheral surface in the transport direction of the vaporizer 10D, there is provided a heating means 21 for heating the liquid raw material 11 to generate the vaporized raw material 13. Connected to the carry-out side of the vaporizer 10D is a vaporized raw material transport pipe 22 for transporting the transport gas 18 mixed with the vaporized raw material 13 to the reaction chamber.
[0068]
  Hereinafter, the operation of the vaporizer 10D configured as described above will be described. A part of the liquid raw material 11 supplied from the liquid raw material supply pipe 63 is vaporized by touching the bottom surface in the vaporizer 10D heated by the heating means 21 set at 250 ° C., for example. The liquid raw material 11 is introduced into the vaporizing chamber 65 in a liquid state. The bottom surface of the vaporizing chamber 65 is ultrasonically vibrated by the ultrasonic oscillator 62, and the liquid raw material 11 supplied as a liquid to the inside of the vaporizing chamber 65 becomes particulate droplets 16 by the ultrasonic vibration of the bottom surface. Since the liquid droplets 16 are very fine particles, their heat capacity is small, so they are easily vaporized at a temperature of about 250 ° C. to become the vaporized raw material 13. The vaporized raw material 12 generated by the vaporizer 10D is sent to the vaporized raw material transport pipe 22 together with the transport gas 18 supplied from the transport gas supply pipe 19,Second reference formIn the same manner as above, it is supplied to the reaction chamber.
[0069]
  Like thisreferenceAccording to the vaporizer 10D according to the embodiment, the process of generating the particulate droplet 16 from the liquid raw material 11 and generating the vaporized raw material 13 from the droplet 16 can be performed in one vaporization chamber 65. Further simplification can be achieved.
[0070]
  Further, since the area of the wall surface that is touched when the droplet 16 is transported to the transport gas 18 can be reduced, the occurrence of reliquefaction due to the droplet 16 adhering to the wall surface can be reduced, so that more efficient. Can be supplied to the reaction chamber.
[0071]
  In addition, even if a residue is generated inside the vaporizer 10D due to long-term operation, only the device needs to be cleaned or replaced, and maintenance is easy.
[0072]
  In addition, when the liquid raw material 11 is supplied to the vaporizing chamber 65, the supply amount of the vaporized raw material 13 may become unstable at the beginning of operation due to direct heating and vaporization by touching the bottom surface of the vaporizing chamber 65. Conceivable. In order to prevent this, the heating means 21 may not be provided at the bottom of the vaporizer 10D. Further, while the initial supply amount is unstable, the vaporized raw material 13 may be directly exhausted to the exhaust means without being supplied to the reaction chamber.
[0073]
  Further, although the ultrasonic transmitter 62 is provided outside the bottom of the vaporizer 10 </ b> D, it is not limited to this and may be on the bottom surface in the vaporization chamber 65.
[0074]
  (Fourth reference form)
  Hereinafter, the present inventionFourth reference formWill be described with reference to the drawings.
[0075]
  FIG. 5 illustrates the present invention.Fourth reference formIt is a composition sectional view of the vaporizer concerning. In FIG. 5, the same members as those shown in FIG. The vaporization apparatus 10E shown in FIG. 5 heats the droplet 16 generated by the droplet generator 66 having the ultrasonic transmitter 62 provided to be in close contact with the outside of the bottom, and the droplet 16 generated by the droplet generator 66. And vaporized raw material generating means 67 for generating the vaporized raw material 13 from the liquid raw material 11 by vaporizing. Thus, the configuration has both the advantages of the vaporizer 10C shown in FIG. 3 and the advantages of the vaporizer 10D shown in FIG. That is, since the vaporizer 10E has a configuration in which the vaporizer 10C including the atomization chamber 61 and the vaporizer 14 illustrated in FIG. 3 is integrated, it is possible to reduce the occurrence of reliquefaction, and thus a more efficient vaporization raw material. Can be generated, and the structure of the apparatus can be simplified and the maintenance of the apparatus can be facilitated.
[0076]
  Further, the vaporizer 10E is separated into the droplet generating means 66 and the vaporized raw material generating means 67, and the stepped portion is set so that the bottom surface of the vaporized raw material generating means 67 is higher than the bottom surface of the droplet generating means 66. Therefore, the liquid raw material 11 at the beginning of operation is not heated and vaporized by directly touching the bottom of the vaporized raw material generating means 67. Therefore, the vaporized raw material 13 is stably supplied from the beginning of operation.
[0077]
  Instead of setting a stepped portion on the bottom surface of the vaporized raw material generating unit 67 and the bottom surface of the droplet generating unit 66, the height of the stepped portion is approximately between the vaporized raw material generating unit 67 and the droplet generating unit 66. The same effect can be obtained even if the screen is provided.
[0078]
  Further, although the ultrasonic transmitter 62 is provided outside the bottom of the droplet generating unit 66, the present invention is not limited to this and may be on the bottom surface inside the droplet generating unit 66.
[0079]
【The invention's effect】
  The present inventionAccording to the vaporization apparatus according to the present invention, since the ultrasonic oscillator vibrates the liquid surface of the liquid raw material with ultrasonic waves, extremely fine particulate droplets are generated from the liquid raw material, so that the vaporized raw material obtained by heating becomes uniform. Therefore, the vaporized raw material can be supplied stably.
[0080]
  In addition, since there is no foreign matter mixed in the vaporized raw material, a filter for filtering the foreign material is not necessary in the vaporized raw material passage. Maintenance becomes easy.
[0081]
  In addition, since the supply amount of the particulate liquid raw material does not change with time, a stable vaporized raw material can be supplied over a long period of time.
[0082]
  Furthermore, since the inside of the vaporized raw material conveyance pipe is provided with a mixing prevention means for preventing unnecessary liquid droplets adhering to the inner wall surface of the vaporized raw material conveyance pipe from being mixed into the liquid raw material, the liquid raw material is converted into unnecessary liquid droplets. Since it is not contaminated, the quality of the vaporized raw material can be kept stable.
[Brief description of the drawings]
FIG. 1 of the present inventionFirst reference form1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer.
FIG. 2 of the present inventionFirst embodiment1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer.
FIG. 3 of the present inventionSecond reference form1 is a configuration cross-sectional view of a vaporizer according to the present invention and a CVD apparatus using the vaporizer.
FIG. 4 of the present inventionThird reference formIt is a composition sectional view of the vaporizer concerning.
FIG. 5 shows the present invention.Fourth reference formIt is a composition sectional view of the vaporizer concerning.
FIG. 6 is a cross-sectional view of a conventional solution vaporization type CVD apparatus.
[Explanation of symbols]
    1 CVD equipment
    10A vaporizer
    10B vaporizer
    10C vaporizer
    10D vaporizer
    10E vaporizer
    11 Liquid raw materials
    12 Liquid raw material container
    13 Vaporizing raw material
    14 Vaporizer (Vaporization raw material generation means)
    15 ultrasound
    16 droplets
    16a droplet
    17 Ultrasonic oscillator
    18 Transport gas
    19 Transport gas supply pipe
    20 Unloading pipe (vaporized raw material carrying pipe)
    21 Heating means
    22 Vaporized raw material transfer pipe
    23 Thermal insulation heater (thermal insulation means)
    30 Cone
    31 Enlarged part
    32 discharge pipe
    33 Cooling means
    34A Cooling water
    34B Cooling water
    50 reactor
    51 reaction chamber
    51A Vaporization raw material generator
    51B Reaction chamber (deposition unit)
    52 Vaporization Raw Material Introduction Department
    53 Reactor heating means
    54 substrates
    55 Substrate holder
    56 Sheath resistance heater (substrate heating means)
    57 reaction gas
    58 Reaction gas supply pipe
    59 Exhaust means
    61 Atomization chamber (droplet generation means)
    62 Ultrasonic transmitter
    63 Liquid material supply pipe
    64 Liquid raw material supplier
    65 Vaporization chamber
    66 Droplet generation means
    67 Vaporizing raw material generation means

Claims (9)

A liquid material container for storing the liquid material;
An ultrasonic oscillator that is provided in the liquid raw material container and generates liquid droplets on the liquid surface from the liquid raw material by vibrating the liquid surface of the liquid raw material with ultrasonic waves;
A transport gas supply pipe for supplying a transport gas mixed with the liquid droplets to transport the liquid droplets into the liquid source container;
A vaporized raw material transport pipe for transporting the generated vaporized raw material while generating the vaporized raw material by heating and vaporizing with the heating means while transporting the droplet mixed with the transport gas in the liquid raw material container A vaporizing device comprising:
Vaporization characterized by further comprising mixing prevention means provided inside the vaporized raw material transport pipe and preventing the droplets adhering to the inner wall surface of the vaporized raw material transport pipe from mixing into the liquid raw material. apparatus.   The mixing preventing means is provided in the enlarged portion in which the inner diameter of the vaporized raw material transport pipe is partially enlarged, and the enlarged portion is provided with an apex located in the transport direction and a peripheral end portion in the enlarged portion. The vaporizer according to claim 1, further comprising a conical body positioned outside the inner wall surface of the raw material transport pipe.   2. The vaporization according to claim 1, further comprising a cooling unit that cools the droplets so that the droplets transported in the vaporized raw material transport pipe are not vaporized before being heated by the heating unit. apparatus.   4. The vaporizer according to claim 3, wherein the cooling means cools the droplets to about room temperature. A vaporizer according to claim 1;
A reaction furnace connected to the discharge side of the vaporized raw material transport pipe of the vaporizer and reacting by heating the vaporized raw material transported by the vaporized raw material transport pipe;
A substrate holder that is provided inside the reactor and holds the substrate;
A CVD apparatus, comprising: a reaction furnace heating means provided in the reaction furnace for heating the reaction furnace.   6. The CVD apparatus according to claim 5, wherein the substrate holder has a substrate heating means for heating the substrate to a predetermined temperature.   The CVD apparatus according to claim 5, further comprising a reaction gas supply pipe that supplies a reaction gas that reacts with the vaporized raw material into the reaction furnace. The CVD apparatus according to claim 7, wherein the reaction gas supplied from the reaction gas supply pipe includes at least one of O ₂ , NO, N ₂ O, and O ₃ .   A vaporized raw material is generated from a liquid raw material by the vaporization apparatus according to claim 1, and the vaporized raw material is decomposed on a surface of a substrate that is installed in a reaction furnace and is heated to a temperature at which the vaporized raw material is decomposed or higher. A thin film manufacturing method, comprising depositing a thin film on the substrate.

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