JP5179823B2 - Vaporizer and film forming apparatus - Google Patents

Description

  The present invention relates to a vaporizer that vaporizes a liquid raw material to generate a raw material gas, and a film forming apparatus including the vaporizer.

  In general, as a method of depositing various thin films composed of dielectrics, metals, semiconductors, etc., an organic source gas such as an organometallic compound is supplied to the deposition chamber and reacted with other gases such as oxygen and ammonia. A chemical vapor deposition (CVD) method for forming a film is known. Since many organic raw materials used in such a CVD method are liquid or solid at room temperature, a vaporizer for vaporizing the organic raw materials is required. For example, the organic raw material is usually made into a liquid raw material by diluting or dissolving it with a solvent.

  As a vaporizer for generating a raw material gas by vaporizing such a liquid raw material, conventionally, for example, a vaporization surface having a large number of holes is provided in the vaporization chamber, and this vaporization surface is heated by a heater or the like. There is one in which a droplet is made to come into contact with the vaporization surface to be vaporized by spraying the droplets into a droplet (mist) on the vaporization surface on the carrier gas flow.

  In such a vaporizer, in order to increase the vaporization efficiency, it is desirable to spray the liquid raw material into droplets having a diameter as small as possible and spray the vaporized surface. However, the smaller the diameter of the droplet, the more likely it will pass through the hole without contacting the vaporization surface. The droplets that could not be vaporized in this way enter the film formation chamber on the carrier gas stream and cause generation of particles. For example, if a liquid source droplet that could not be vaporized entered the deposition chamber and oxygen remained in the deposition chamber, the droplet would oxidize into fine particles that would adhere to the substrate. There is a problem that abnormal film formation and film quality defects occur.

  For this reason, conventionally, the raw material gas generated by the vaporizer is supplied to the film forming chamber through a filter having minute holes, and this filter is heated from the outside and the liquid contained in the raw material gas cannot be completely evaporated. The droplets were vaporized with a filter. According to this, even if the vaporization efficiency of the vaporizer itself is somewhat poor, it is possible to prevent the liquid droplets that could not be vaporized from entering the film forming chamber as they are.

  In addition, in order to increase the vaporization efficiency, a breathable member having fine pores such as a solid packing having a pore or a porous body is arranged, and this breathable member is heated from the outside by a heating means such as a heater. Some of them are vaporized through liquid material droplets in a state (see, for example, Patent Documents 1 and 2). According to this, since the possibility that the droplet contacts the breathable member increases, the vaporization efficiency can be improved.

JP 2005-347598 A Japanese Patent Laid-Open No. 10-85581

  However, since air-permeable members such as solid fillers, porous bodies, and filters that have been conventionally used to vaporize liquid raw material droplets are heated from the outside by a heating means such as a heater, the air-permeable members The amount of heat could not be supplied uniformly throughout. Among the breathable members, for example, there are portions where the temperature is low, for example, a portion where the amount of heat is not sufficiently reached because of being away from the heating means, there is a possibility that the droplets are not vaporized and clogged.

  For example, in the vaporizer described in Patent Document 1, since the solid packing is heated by the heating means on the outside thereof, the temperature of the central area is lower than the outer peripheral area close to the heating means in the solid packing. It is difficult to make the temperature of the entire packing uniform. In such a case, the temperature of the central region does not reach the temperature at which the liquid raw material can be vaporized, and vaporization failure occurs and the solid packing is clogged.

  In contrast, in the vaporizer described in Patent Document 2, in order to efficiently vaporize the liquid raw material without causing clogging in the porous body, a flow path passing through a part of the porous body is provided. Heating is performed from the inside of the porous body by circulating a heat medium through the flow path. However, this is not enough. That is, since the flow path through which the heat medium flows is only disposed in a part of the porous body, it is not possible to supply heat uniformly over the entire porous body. For this reason, the vaporization failure partially occurs and the possibility of clogging the porous body cannot be wiped out. In addition, if it is intended to supply heat uniformly over the entire porous body, it may be sufficient to form a flow path throughout the entire porous body, but this makes the structure complicated. In addition, the surface area that can be contacted by the source gas is reduced by the amount formed by the flow path, and the pressure loss in the porous body increases. This makes it impossible to obtain a raw material gas having a predetermined flow rate.

  Therefore, the present invention has been made in view of such problems, and an object of the present invention is to make the temperature of the entire breathable member uniform when vaporizing liquid raw material droplets through the breathable member. It is an object of the present invention to provide a vaporizer and a film forming apparatus that can prevent clogging without being vaporized.

  In order to solve the above problems, according to an aspect of the present invention, a liquid material discharge means for discharging a liquid material in the form of droplets, an introduction port for introducing the droplet-like liquid material, and the introduction port A plate-like air-permeable member made of a member having an electric resistance that generates heat when energized, a pair of electrodes arranged so as to sandwich the air-permeable member, and the pair of A power source for generating heat by energizing the breathable member through an electrode, and a raw material gas generated by vaporizing the liquid material in the form of droplets from the inlet through the heated breathable member A vaporizer is provided, characterized in that the vaporizer is provided with a delivery port for delivering the gas to the outside.

  In order to solve the above problems, according to another aspect of the present invention, a film forming process is performed on a substrate to be processed by introducing a source gas from a vaporizer that generates a source gas by vaporizing a liquid source. A film forming apparatus including a film chamber, wherein the vaporizer includes a liquid source discharge unit that discharges a liquid source in the form of droplets, an inlet for introducing the droplet-like liquid source, and an inlet for the inlet A plate-like air-permeable member made of a member having an electric resistance that is arranged to be opposed and generates heat when energized, a pair of electrodes arranged to face each other so as to sandwich the air-permeable member, and the pair of electrodes A power source for generating heat by energizing the breathable member through a gas source, and a raw material gas generated by vaporizing the liquid material in the form of droplets from the inlet through the heated breathable member A delivery port for feeding to the film formation chamber Film forming apparatus is provided, wherein.

  According to the present invention, since the breathable member is composed of a member having an electrical resistance that generates heat when energized, by directly energizing the breathable member via the pair of electrodes, the entire breathable member is provided. Can generate heat. As a result, the temperature of the air-permeable member can be made uniform throughout, so that all the liquid droplets can be vaporized evenly by simply passing the liquid material in the form of liquid droplets through the air-permeable member. Thereby, while being able to improve vaporization efficiency more than before, since the vaporization defect by a partial temperature fall can be prevented, clogging of a breathable member can be prevented.

  Each of the pair of electrodes is provided, for example, so as to cover the front surface and the back surface of the breathable member facing the introduction port so as to cover each surface, and each of the pair of electrodes has a plurality of through holes. You may comprise so that it may form. According to this, since the area where a pair of electrodes contact the air-permeable member can be increased, heat can be generated efficiently. Therefore, for example, when the air-permeable member is energized, it can be quickly raised to a desired temperature throughout.

  In addition, the air-permeable member may be formed in a rectangular plate shape, and the pair of electrodes may be provided so as to cover the respective surfaces of the air-permeable member facing each other. According to this, compared with the case where electrodes are provided on the front side surface and the back side surface facing the introduction port, it is possible to improve the ease of flow of the liquid material in liquid droplets, that is, the conductance.

  The air-permeable member is composed of a resistance heating element made of, for example, a porous material. In this case, the porous material preferably contains silicon carbide. The breathable member may be formed of a resistance heating element made of a fiber material.

  In order to solve the above problems, according to another aspect of the present invention, a vaporizer connected to another vaporizer that vaporizes a liquid raw material to generate a raw material gas, which is generated by the other vaporizer. An inlet for introducing the raw material gas, a plate-like breathable member that is disposed opposite to the inlet and has an electric resistance that generates heat when energized, and the breathable member A pair of electrodes arranged opposite to each other, a power source for energizing the breathable member through the pair of electrodes to generate heat, and the source gas from the other vaporizer introduced from the introduction port has generated heat. There is provided a vaporizer characterized by comprising a delivery port that feeds outside through the inside of the breathable member.

  According to the present invention as described above, by passing the raw material gas generated in the other vaporizer through the gas-permeable member in the vaporizer constituted by the member having electric resistance that generates heat when energized, the vaporization is performed in the other vaporizer. Droplets that could not be vaporized can also be vaporized by the vaporizer according to the present invention.

  In order to solve the above problems, according to another aspect of the present invention, a film forming process is performed on a substrate to be processed by introducing a source gas from a vaporizer that generates a source gas by vaporizing a liquid source. A film forming apparatus including a film chamber, wherein the vaporizer includes a first vaporizer that vaporizes a liquid raw material to generate a raw material gas, and a second vaporizer connected thereto, and the second vaporizer. The carburetor is a plate-like member composed of an introduction port for introducing the raw material gas generated by the first vaporizer and a member having an electrical resistance that is disposed opposite to the introduction port and generates heat when energized. A breathable member, a pair of electrodes arranged so as to sandwich the breathable member, a power source for energizing the breathable member through the pair of electrodes and generating heat, and introduced from the introduction port The breathability that generated heat from the source gas from the first vaporizer Film forming apparatus characterized by comprising a delivery port delivering through the interior of the timber into the deposition chamber is provided.

  According to the present invention, the first gas generated by the first vaporizer is passed through the gas permeable member of the second vaporizer constituted by a member having an electrical resistance that generates heat when energized. Even the droplets that could not be vaporized by this vaporizer can be vaporized by the second vaporizer. Thereby, it is possible to prevent liquid material droplets from entering the film forming chamber and the like together with the material gas.

  According to the present invention, when the liquid raw material droplet is vaporized through the air permeable member, heat can be generated over the entire air permeable member by directly energizing the air permeable member. As a result, the temperature of the air-permeable member can be made uniform throughout, so that all the droplets can be vaporized uniformly. Thereby, while being able to improve vaporization efficiency more than before, since the vaporization defect by a partial temperature fall can be prevented, clogging of a breathable member can be prevented.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(Film Forming Apparatus According to First Embodiment)
First, a film forming apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a schematic configuration example of a film forming apparatus according to the first embodiment. A film forming apparatus 100 shown in FIG. 1 forms a metal oxide film on a substrate to be processed, for example, a semiconductor wafer (hereinafter simply referred to as “wafer”) W by a CVD method, and contains Hf (hafnium). A liquid source supply source 110 that supplies a liquid source made of an organic compound, a carrier gas supply source 120 that supplies a carrier gas, and a vaporizer that generates a source gas by vaporizing the liquid source supplied from the liquid source supply source 110 300, a film forming chamber 200 for forming, for example, an HfO ₂ film on the wafer W using the source gas generated by the vaporizer 300, and a control unit 140 for controlling each part of the film forming apparatus 100. For example, an inert gas such as Ar can be used as the carrier gas.

  The liquid source supply source 110 and the vaporizer 300 are connected by a liquid source supply pipe 112, and the carrier gas supply source 120 and the vaporizer 300 are connected by a carrier gas supply pipe 122. The chambers 200 are connected by a source gas supply pipe 132. The liquid source supply pipe 112 is provided with a liquid source flow control valve 114, the carrier gas supply pipe 122 is provided with a carrier gas flow control valve 124, and the source gas supply pipe 132 is provided with a source gas flow control valve 134. The liquid raw material flow rate control valve 114, the carrier gas flow rate control valve 124, and the raw material gas flow rate control valve 134 are each adjusted in opening degree by a control signal from the control unit 140. The control unit 140 outputs a control signal according to the flow rate of the liquid source flowing through the liquid source supply pipe 112, the flow rate of the carrier gas flowing through the carrier gas supply pipe 122, and the flow rate of the source gas flowing through the source gas supply pipe 132. Is preferred.

  The film formation chamber 200 has, for example, a substantially cylindrical side wall, and includes a susceptor 222 on which the wafer W is horizontally placed in an internal space surrounded by the side wall, the top wall 210 and the bottom wall 212. The The side wall, the top wall 210 and the bottom wall 212 are made of a metal such as aluminum or stainless steel, for example. The susceptor 222 is supported by a plurality of cylindrical support members 224 (only one is shown here). A heater 226 is embedded in the susceptor 222, and the temperature of the wafer W placed on the susceptor 222 can be adjusted by controlling the power supplied from the power source 228 to the heater 226.

  An exhaust port 230 is formed in the bottom wall 212 of the film forming chamber 200, and an exhaust system 232 is connected to the exhaust port 230. Then, the inside of the film formation chamber 200 can be decompressed to a predetermined degree of vacuum by the exhaust system 232.

  A shower head 240 is attached to the top wall 210 of the film forming chamber 200. A raw material gas supply pipe 132 is connected to the shower head 240, and the raw material gas generated by the vaporizer 300 is introduced into the shower head 240 via the raw material gas supply pipe 132. The shower head 240 has an internal space 242 and a number of gas discharge holes 244 communicating with the internal space 242. The source gas introduced into the internal space 242 of the shower head 240 via the source gas supply pipe 132 is discharged toward the wafer W on the susceptor 222 from the gas discharge hole 244.

  In the film forming apparatus 100 according to the present embodiment, the liquid source supply source 110 stores, for example, HTB (hafnium tarbutoxide) as a liquid source, and the liquid source is vaporized through the liquid source supply pipe 112. To send to.

  In the film forming apparatus 100 having such a configuration, the source gas from the vaporizer 300 is supplied as follows. When the liquid source from the liquid source supply source 110 is supplied to the vaporizer 300 via the liquid source supply line 112 and the carrier gas from the carrier gas supply source 120 is supplied via the carrier gas supply line 122, A liquid source is discharged in the form of droplets together with a carrier gas into a vaporization chamber provided in the vaporizer 300, and the liquid source is vaporized to generate a source gas. The source gas generated in the vaporizer 300 is supplied to the film formation chamber 200 via the source gas supply pipe 132, and a desired process is performed on the wafer W in the film formation chamber 200.

  By the way, in the vaporizer 300 of the film forming apparatus 100 as described above, when the liquid source cannot be completely evaporated, a part of the liquid source droplet is mixed into the source gas and the source gas supply pipe 132 is supplied. There is a risk of entering into the film forming chamber 200. Thus, the liquid material droplets that have entered the film formation chamber 200 may cause deterioration in the film quality of the film formed on the wafer W as particles. According to the vaporizer 300 according to the present embodiment, as will be described below, it is possible to efficiently vaporize all of the liquid material droplets and generate a high quality raw material gas.

(Configuration example of vaporizer according to the first embodiment)
Next, a configuration example of the vaporizer 300 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a longitudinal sectional view showing a schematic configuration example of the vaporizer 300 according to the first embodiment. The vaporizer 300 is roughly composed of a vaporization unit 300B that vaporizes a liquid material, and a liquid material supply unit 300A that supplies the liquid material to the vaporization unit 300B in the form of droplets.

  First, the configuration of the liquid material supply unit 300A will be described. The liquid source supply unit 300A is provided with a liquid source channel 310 extending vertically from the upper surface to the inside, and a carrier gas channel 312 extending horizontally from the side to the inside. A liquid source supply pipe 112 is connected to one end of the liquid source channel 310, and a carrier gas supply pipe 122 is connected to one end of the carrier gas channel 312.

  At the other end of the liquid material flow path 310, a discharge nozzle 316 is provided as a liquid material discharge means having a discharge port 314 for discharging the liquid material in the form of droplets. The discharge nozzle 316 is configured to be tapered, for example (this configuration is omitted in FIG. 2), and is disposed so that the discharge port 314 at the tip thereof faces the internal space of the vaporization unit 300B.

  The diameter of the discharge port 314 of the discharge nozzle 316 is determined according to the target size of the liquid material droplets supplied into the vaporization unit 300B. In order to reliably vaporize the liquid material in the form of droplets in the vaporization unit 300B, it is advantageous that the droplet size is small, and therefore the diameter of the discharge port 314 is preferably small. However, if the droplet size becomes too small, the flow rate of the raw material gas obtained by vaporizing the droplet may be insufficient. It is preferable to determine the diameter of the discharge port 314 in consideration of these points.

  As a constituent material of the discharge nozzle 316, a synthetic resin such as a polyimide resin having resistance to an organic solvent or a metal such as stainless steel or titanium is preferable. Further, by configuring the discharge nozzle 316 with a synthetic resin, it is possible to prevent heat from being conducted from the surroundings to the liquid raw material before being discharged. Further, by using the polyimide resin, it becomes difficult for the residue (precipitate) of the liquid raw material to adhere to the discharge nozzle 316 and the clogging of the nozzle is prevented.

  A carrier gas injection unit 318 is disposed inside the liquid source supply unit 300A so as to surround the tip of the discharge nozzle 316. The carrier gas injection unit 318 is connected to the other end of the carrier gas channel 312 and is configured to eject the carrier gas from the carrier gas channel 312 together with the liquid source toward the vaporization unit 300B.

  Specifically, the carrier gas injection unit 318 is formed in a cup shape surrounding the tip of the discharge nozzle 316, and the carrier gas injection port 320 is formed at the bottom thereof. The carrier gas outlet 320 is formed in the vicinity of the outlet 314 at the tip of the outlet nozzle 316 so as to surround the outlet 314. As a result, the carrier gas can be ejected from around the ejection port 314, and the liquid material droplets ejected from the ejection port 314 are surely caused to fly toward the vaporization unit 300B, which will be described later in the vaporization unit 300B. The air-permeable member 410 can be stably sprayed.

  Next, the configuration of the vaporization unit 300B will be described. The vaporizing unit 300B has a substantially cylindrical casing in which a vaporizing unit 400 described later is disposed. The casing includes a cylindrical side wall member 330 and a top wall member 332 and a bottom wall member 334 provided above and below the side wall member 330, respectively. The side wall member 330, the top wall member 332, and the bottom wall member 334 are each made of a metal such as aluminum or stainless steel.

  The side wall member 330 and the top wall member 332 are coupled by coupling members 338A and 338B such as bolts with the O-ring 336 interposed therebetween, and the side wall member 330 and the bottom wall member 334 sandwich the O-ring 340. Are coupled by coupling members 342A and 342B such as bolts. As a result, the airtightness of the internal space of the vaporizing unit 300B is maintained.

  The top wall member 332 is formed with an introduction port 354 for introducing a liquid raw material droplet, and the bottom wall member 334 is formed with a delivery port 356 for sending the raw material gas. Inside the side wall member 330 is provided vaporization means 400 for vaporizing the liquid material in the form of liquid droplets supplied from the liquid raw material supply unit 300A to generate a raw material gas. The internal space is divided into an upper space 350 and a lower space 352. Liquid droplets of liquid material are introduced into the upper space 350 from the introduction port 354 and sprayed onto the vaporizing means 400. The raw material gas obtained by vaporizing the liquid raw material droplets through the vaporizing means 400 is sent out from the outlet 356 via the lower space 352.

  The vaporizing means 400 according to the present embodiment includes a breathable member 410 that generates heat by energization to vaporize a liquid material in a droplet form, and a pair of first electrodes (a pair of first electrodes) disposed so as to sandwich the upper and lower sides of the breathable member 410. (Front side electrode) 420 and second electrode (back side electrode) 430, and first and second power supply lines 440 and 450 for supplying electric power for energizing the air-permeable member 410 to these electrodes 420 and 430, respectively. Prepare.

  The air-permeable member 410 is a plate-like member having air permeability that allows the flow of the liquid material in the form of liquid droplets and having electric resistance that generates heat when energized. Such a breathable member 410 is formed of a porous resistor such as silicon carbide (SiC) or conductive ceramics. Here, a case where the air permeable member 410 is formed of silicon carbide (SiC), for example, in a disk shape as shown in FIG. 3 will be described as an example.

  As shown in FIG. 2, the air-permeable member 410 has a disk-like first electrode 420 joined to the front surface of the air-permeable member 410 so as to cover the entire surface. A disc-shaped second electrode 430 is joined to the back surface of 410 so as to cover the entire surface.

  In the vaporization unit 300B according to the first embodiment, since the electrodes 420 and 430 are provided on the entire surface of the air-permeable member 410, the air-permeable member 410 is closed against the flow of liquid liquid material. It will end up. Therefore, for example, a plurality of through holes 422 are formed in the first electrode 420 as shown in FIG. 4, and a plurality of through holes 432 are also formed in the second electrode 430 as shown in FIG. The flow of the liquid material in the form of droplets is allowed to pass through the air permeable member 410 through the through hole 422 and the through hole 432.

  That is, the liquid material in the form of liquid droplets discharged from the discharge nozzle 316 and flying in the upper space 350 on the carrier gas flow is guided to the front surface of the air-permeable member 410 through the plurality of through holes 422. Can do. Further, the raw material gas generated by vaporizing the liquid material in the form of liquid droplets through the air-permeable member 410 can be guided to the lower space 352 through the plurality of through holes 432.

  The number, size, arrangement, and the like of the through holes 422 and 432 are not limited to those shown in FIGS. For example, the number of through holes 422 and the number of through holes 432 may be the same or different. Regarding the arrangement, the through holes 422 and the through holes 432 may be arranged coaxially or may be arranged so as to be shifted. In order to make the liquid material in the form of droplets reach the front surface of the breathable member 410 as much as possible, the opening diameter of the through holes 422 formed in the first electrode 420 is increased, or the number of the through holes 422 is increased. Is preferable. Similarly, in order to send the raw material gas that has passed through the air-permeable member 410 to the lower space 352 without delay, the opening diameter of the through-hole 432 formed in the second electrode 430 is increased, or the number of the through-holes 432 is increased. It is preferable to increase the amount.

  However, the opening diameter and the number of the through holes 422 and 432 are set according to the electrical characteristics and size of the breathable member 410 so that the entire breathable member 410 generates heat without unevenness, and the breathable member 410. It is preferable to supply electric power.

  Further, as shown in FIG. 2, a first power supply line 440 is connected to the outer edge portion of the first electrode 420. The first power supply line 440 extends vertically downward and is connected to a first external terminal 366 provided so as to protrude downward from the bottom wall member 334 via the first internal terminal 364. In addition, a second feed line 450 is connected to the outer edge of the second electrode 430. The second power supply line 450 extends downward and is connected to a second external terminal 376 provided so as to protrude downward from the bottom wall member 334 via a second internal terminal 374. For example, an AC power source 380 is connected to the first external terminal 366 and the second external terminal 376.

  Since the air-permeable member 410, the first electrode 420, the second electrode 430, the first power supply line 440, and the second power supply line 450 are conductive members, they are insulated from the casing such as the side wall member 330. . Specifically, the air-permeable member 410, the first electrode 420, and the second electrode 430 are fixed while being insulated by an insulating holding member 344 provided between the side wall member 330 so as to surround the outer periphery thereof. Yes. The first electrode 420 is fixed while being insulated by a ring-shaped insulating clamp member 346 between the first electrode 420 and the top wall member 332.

  The first power supply line 440 is insulated by an insulating holding member 344 and an insulating sleeve 442. The second power supply line 450 is insulated by an insulating holding member 344 and an insulating sleeve 452.

  Here, a terminal structure for supplying power to the first electrode 420 and the second electrode 430 from the outside will be described with reference to FIG. As shown in FIG. 2, the bottom wall member 334 is provided with a first terminal portion 360 for supplying power to the first electrode 420 and a second terminal portion 370 for supplying power to the second electrode 430. ing.

  The first terminal portion 360 protrudes above the housing member 368 in a state of being connected to the first external terminal 366 and a housing member 368 made of an insulating material that accommodates the first external terminal 366 in a state where the tip protrudes downward. And a first internal terminal 364 provided. Further, the second terminal portion 370 includes a housing member 378 made of an insulating material that accommodates the second external terminal 376 with its tip protruding downward, and an upper portion of the housing member 378 in a state connected to the second external terminal 376. And a second internal terminal 374 provided so as to protrude from the terminal. Both the housing member 368 and the housing member 378 are fitted into attachment holes formed in the bottom wall member 334, and are firmly fixed by brazing or the like. As a result, the airtightness of the internal space of the vaporizing unit 300B is maintained.

  In the terminal structure configured as described above, when the bottom wall member 334 to which the first terminal portion 360 and the second terminal portion 370 are fixed is attached to the side wall member 330, the first internal terminal 364 is connected to the first terminal portion 360. In addition, the second internal terminal 374 enters the side wall member 330 together with the second terminal portion 370, and is electrically connected to the other end of the first power supply line 440 and the other end of the second power supply line 450, respectively. This facilitates the attachment of the terminals when assembling the vaporizer. The terminal structure is not limited to that described above, and may be detachably provided on the bottom wall member 334 or the side wall member 330, for example.

  In such a vaporizing means 400, an alternating current is supplied to the first external terminal 366 and the second external terminal 376 by the alternating current power supply 380, so that the air permeable member 410 is directly connected to the air through the first electrode 420 and the second electrode 430. It can be energized. Thereby, by controlling the output value of the AC power supply 380, the heat generation temperature of the breathable member 410 can be directly adjusted.

  Further, by providing a temperature sensor such as a thermocouple 390 in the vicinity of the air-permeable member 410, a change in voltage generated in the thermocouple 390 can be measured by an external measuring instrument 392, for example. The measurement data is transmitted to the control unit 140. The control unit 140 can control the output value of the AC power source 380 based on the data received from the measuring instrument 392 and adjust the heat generation temperature of the breathable member 410.

(Operation of the deposition system)
The operation of the film forming apparatus 100 according to the present embodiment configured as described above will be described with reference to the drawings. In generating the raw material gas by the vaporizer 300, the opening degree of the liquid raw material flow rate control valve 114 is adjusted, and a liquid raw material having a predetermined flow rate is supplied from the liquid raw material supply source 110 via the liquid raw material supply pipe 112. To supply. At the same time, the opening degree of the carrier gas flow rate control valve 124 is adjusted, and a carrier gas having a predetermined flow rate is supplied from the carrier gas supply source 120 to the vaporizer 300 via the carrier gas supply pipe 122.

  Further, the vaporizer 300 outputs AC power from the AC power source 380 to cause the breathable member 410 to generate heat. At this time, the voltage generated in the thermocouple 390, that is, the temperature of the air-permeable member 410 is measured by the measuring instrument 392. Then, the control unit 140 controls the AC power source 380 based on the measurement result to adjust the breathable member 410 to a predetermined temperature that is at least higher than the vaporization temperature of the liquid raw material.

  The liquid raw material supplied to the vaporizer 300 via the liquid raw material supply pipe 112 reaches the discharge nozzle 316 via the liquid raw material flow path 310 and is discharged as droplets from the discharge port 314. The carrier gas supplied to the vaporizer 300 via the carrier gas supply pipe 122 along with the supply of the liquid raw material reaches the carrier gas injection unit 318 via the carrier gas channel 312 and is vaporized from the carrier gas outlet 320. Injected toward the upper space 350 of the part 300B. Since the jetted carrier gas passes through the vicinity of the discharge port 314 of the discharge nozzle 316, liquid material droplets continuously discharged from the discharge port 314 are put on the flow in the direction of the vaporizing means 400. It is possible to fly stably.

  The liquid material in the form of droplets that has entered the upper space 350 of the vaporization unit 300B and is sprayed onto the vaporization means 400 enters the air-permeable member 410 through the through-hole 422 of the first electrode 420. At this time, the air-permeable member 410 is heated to a resistance and adjusted to a predetermined temperature higher than the vaporization temperature of the liquid raw material. Accordingly, the liquid material in the form of droplets that has entered the gas permeable member 410 into the gas permeable member 410 is instantly vaporized to obtain a material gas.

  Since the first electrode 420 is in close contact with the heat-permeable breathable member 410, the temperature thereof is substantially equal to the temperature of the breathable member 410. For this reason, it is conceivable that a part of the liquid material in the form of droplets comes into contact with the first electrode 420, but even in such a case, as in the case of contact with the surface of the air-permeable member 410, it is instantly vaporized. It rides on the flow of the carrier gas and is led to the breathable member 410 through the through hole 422.

  In this way, the raw material gas generated by vaporizing the liquid material in the form of liquid droplets through the gas permeable member 410 passes through the gas permeable member 410 to the back side surface together with the carrier gas. It is sent to the source gas supply pipe 132 via the side space 352 and the delivery port 356.

The source gas sent to the source gas supply pipe 132 is supplied to the film forming chamber 200, introduced into the internal space 242 of the shower head 240, and discharged toward the wafer W on the susceptor 222 from the gas discharge hole 244. Then, a predetermined film such as an HfO ₂ film is formed on the wafer W. The flow rate of the source gas introduced into the film forming chamber 200 can be adjusted by controlling the opening degree of the source gas flow rate control valve 134 provided in the source gas supply pipe 132.

  As described above, according to the first embodiment, since the air-permeable member 410 can be directly energized to generate heat, heat can be generated throughout the air-permeable member 410. As a result, the temperature of the air-permeable member 410 can be made uniform throughout, so that all the liquid droplets can be vaporized evenly by simply passing the liquid material in the form of liquid droplets through the air-permeable member 410. Thereby, vaporization efficiency can be improved more than before. In addition, since vaporization failure due to partial temperature drop can be prevented, clogging of the breathable member can be prevented. Therefore, the maintenance cycle of the vaporizing means 400 including the breathable member 410 can be extended. Thereby, the throughput in the film forming apparatus 100 can also be improved.

  In addition, since the electrodes 420 and 430 according to the first embodiment are provided, for example, so as to cover the front surface and the back surface of the breathable member 410 so as to cover the respective surfaces, the electrodes 420 and 430 are provided with the breathable member 410. Since the area in contact with can be increased, heat can be generated efficiently. Therefore, for example, when the air-permeable member 410 is energized, it can be quickly raised to a desired temperature throughout.

  Compared to the conventional configuration in which the member for vaporizing the liquid material is heated from the outside, the configuration for supplying power to the air-permeable member 410 according to the present embodiment is a simple configuration in which electrodes are arranged. It is. Therefore, the manufacturing cost of the vaporizer 300 can be reduced, and the maintenance cost can be reduced. Further, according to the present embodiment, since it is not necessary to provide a heat medium flow path inside the air-permeable member 410, the flow path of the source gas is not blocked, and the pressure loss in the vaporizing means 400 is minimized. Can be suppressed. As a result, a source gas having a sufficient flow rate can be introduced into the film formation chamber 200.

  The temperature of the breathable member 410 is directly monitored by a temperature sensor such as a thermocouple 390, and the output value of the AC power supply 380 is controlled by the control unit 140 based on the measured temperature. , The temperature of the breathable member 410 can be accurately controlled. For this reason, the temperature of the whole air permeable member 410 can be kept uniform, without reducing the temperature of the whole air permeable member 410. Therefore, the liquid material in the form of droplets passing through the air-permeable member 410 can be reliably vaporized.

  Further, according to the vaporizer 300 according to the first embodiment, the heat generation temperature of the air-permeable member 410 can be controlled in accordance with the type and amount of the liquid raw material and the size of the liquid droplets. The raw material can be surely vaporized.

  In the first embodiment, the vaporizing unit 300B is configured so that the air-permeable member has a disk shape, and the pair of electrodes are respectively covered on the front surface and the back surface facing the inlet of the air-permeable member. However, the present invention is not limited to this. For example, the vaporizing unit may be configured such that the air-permeable member is formed in a rectangular plate shape, and the pair of electrodes are respectively joined to the opposite side surfaces of the air-permeable member so as to cover each surface.

(Variation of the vaporizer according to the first embodiment)
A modification of the vaporizer 300 will be described with reference to the drawings. FIG. 6 is a longitudinal sectional view showing a schematic configuration example of a vaporizer 300 according to a modification of the first embodiment. FIG. 7 is a cross-sectional view of the vaporizer shown in FIG. The vaporizer 300 shown in FIG. 6 differs from the vaporizer 300 shown in FIG. 1 only in the configuration of the vaporizer 300B. Specifically, the vaporizer 300 shown in FIG. 6 differs from the vaporizer 400 shown in FIG. 1 in the configuration of the vaporizer 402, and the other functions are the same as those of the vaporizer 300 shown in FIG. The same reference numerals are given to the portions having the above and detailed description thereof is omitted.

  The vaporizing means 402 shown in FIG. 6 has a pair of air-permeable members 412 that generate heat by energization to vaporize the liquid material in the form of droplets and are opposed to each other so as to sandwich both side ends of the air-permeable members 412. The 1st electrode 424 and the 2nd electrode 434, The 1st electric power feeding line 440 and the 2nd electric power feeding line 450 which supply the electric power for energizing the air-permeable member 412 to each of these electrodes 424 and 434, respectively, are provided.

  The air-permeable member 412 shown in FIG. 6 is a plate-like member having air resistance that allows the flow of the liquid material in the form of liquid droplets and electric resistance that generates heat when energized, as with the air-permeable member 410 shown in FIG. is there. Here, a case where the air-permeable member 412 is formed of silicon carbide (SiC) into a rectangular shape as shown in FIG. 7 is taken as an example.

  Such a breathable member 412 has a long first electrode (one side electrode) 424 bonded to one side surface of the breathable member 412 so as to cover the entire surface as shown in FIG. A long second electrode (another side electrode) 434 is joined to the other side surface of the air-permeable member 412 so as to cover the entire surface. With this configuration, the electrodes 424 and 434 can be arranged without blocking the air-permeable member 410 against the flow of liquid liquid material in the form of droplets. Thereby, compared with the case where electrodes are provided on the front side surface and the back side surface of the breathable member, it is possible to improve the ease of flow of the liquid material in the form of liquid droplets, that is, the conductance. Therefore, more liquid material in the form of liquid droplets can be vaporized in a short time, so that more raw material gas can be generated.

  By the way, the air permeable member 410 and the air permeable member 412 according to the first embodiment are both plate-like members. With regard to the thickness of the plate-like member, the pressure loss in the vaporizing means 400 and 402 can be reduced as the thickness becomes thinner as long as the passage of liquid material in the form of droplets can be prevented. In this way, a larger amount of source gas can be introduced into the film formation chamber 200.

  Further, a member thinner than the plate-like air-permeable members 410 and 412, for example, a sheet-like member may be used for the vaporizing means 400 and 402. In this case, a sheet-like member can be comprised with a fiber material. The sheet-like member may be a woven fabric or a non-woven fabric. Moreover, as such a fiber material, a metal fiber or a carbon fiber can be used.

  The vaporizer 300 according to the first embodiment has been described with respect to the case where the liquid raw material supply unit 300A and the vaporization unit 300B are integrally configured. However, the present invention is not limited to this, and the liquid raw material supply unit 300A and the vaporization unit 300B are vaporized. The unit 300B may be configured separately. In that case, the liquid raw material supply unit 300A may be replaced with another vaporizer, and the vaporization unit 300B may be a single vaporizer. That is, it connects so that the raw material gas produced | generated with the other vaporizer may be introduce | transduced from the inlet 354 of the vaporizer which consists of only the vaporization part 300B. According to this, the raw material gas generated by another vaporizer (for example, an existing vaporizer or a vaporizer with low vaporization efficiency such as a conventional vaporizer) is passed through the air-permeable member 410 that is heated by energization. Thus, the liquid droplets that could not be vaporized by other vaporizers can also be vaporized by the vaporizer having the configuration of the vaporization unit 300B according to the first embodiment.

(Film Forming Apparatus According to Second Embodiment)
Next, a film forming apparatus according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a diagram for explaining a schematic configuration example of a film forming apparatus according to the second embodiment. Here, a case will be described in which the vaporizer 302 used in the film forming apparatus is configured by a first vaporizer 304 and a second vaporizer 308 connected to the vaporizer 302 by a connection pipe 306. 8 is the same as that shown in FIG. 1 except for the configuration of the carburetor. Therefore, portions having the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  Specifically, the vaporizer 302 according to the second embodiment includes a first vaporizer 304 that vaporizes a liquid raw material supplied from the liquid raw material supply source 110 to generate a raw material gas, and a first vaporizer 304. And a second vaporizer 308 connected to the introduction port via the connection pipe 306, and the raw material gas discharged from the discharge port of the second vaporizer 308 is used as the raw material gas. It is configured to be supplied to the film forming chamber via the supply pipe 132.

  The configuration of the second vaporizer 308 according to the second embodiment is shown, for example, in FIG. The configuration of the second vaporizer 308 is a vaporizer composed of only the vaporizer 300B of the vaporizer 300 according to the first embodiment. The vaporizer shown in FIG. 9 is a vaporizer composed of only the vaporizer 300B shown in FIG. Further, the second vaporizer 308 may be the vaporizer shown in FIG. The vaporizer shown in FIG. 10 is a vaporizer composed of only the vaporizer 300B shown in FIG. Accordingly, since the second vaporizer 308 has the same configuration as the vaporizer 300B shown in FIG. 2 or FIG. 6, the parts having the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  On the other hand, the first vaporizer 304 is a conventional vaporizer that generates a raw material gas by vaporizing the liquid raw material supplied from the liquid raw material supply source 110, regardless of its configuration or type. A vaporizer may be used.

  According to the present invention as described above, the first vaporizer 304 is made to pass the raw material gas generated by the first vaporizer 304 through the air-permeable member that is heated by energization in the second vaporizer 308. The droplets that could not be vaporized can also be vaporized by the second vaporizer 308. Accordingly, it is possible to prevent liquid source droplets from entering the film forming chamber 200 and the like together with the source gas.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, the present invention relates to a vaporizer, a vaporization module, and a component thereof used in an MOCVD apparatus, a plasma CVD apparatus, an ALD (atomic layer deposition) apparatus, an LP-CVD (batch type, vertical type, horizontal type, minibatch type). It can also be applied to a membrane device.

  The present invention can be applied to a vaporizer that vaporizes a liquid raw material to generate a raw material gas and these film forming apparatuses.

It is a figure which shows the example of schematic structure of the film-forming apparatus concerning 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the structural example of the vaporizer | carburetor concerning the embodiment. It is a top view of the air permeable member shown in FIG. It is a top view of the 1st electrode shown in FIG. It is a top view of the 2nd electrode shown in FIG. It is a longitudinal cross-sectional view which shows the modification of the vaporizer | carburetor concerning the embodiment. It is AA sectional drawing shown in FIG. It is a figure which shows the example of schematic structure of the film-forming apparatus concerning 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the structural example of the vaporizer | carburetor concerning the embodiment. It is a longitudinal cross-sectional view which shows the modification of the vaporizer | carburetor concerning the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Film-forming apparatus 110 Liquid raw material supply source 112 Liquid raw material supply piping 114 Liquid raw material flow control valve 120 Carrier gas supply source 122 Carrier gas supply piping 124 Carrier gas flow control valve 132 Raw material gas supply piping 132 Outlet 134 Raw material gas flow control valve 140 Control Unit 200 Film Formation Chamber 210 Top Wall 212 Bottom Wall 222 Susceptor 224 Support Member 226 Heater 228 Power Supply 230 Exhaust Port 232 Exhaust System 240 Shower Head 242 Internal Space 244 Gas Discharge Hole 300 Vaporizer 300A Liquid Material Supply Unit 300B Vaporizer 304 First vaporizer 306 Connection pipe 308 Second vaporizer 310 Liquid source flow channel 312 Carrier gas flow channel 314 Discharge port 316 Discharge nozzle 318 Carrier gas injection unit 320 Carrier gas discharge port 330 Side wall member 3 32 Top wall member 334 Bottom wall member 336, 340 O-ring 338A, 338B coupling member 342A, 342B coupling member 344 insulation holding member 346 insulation clamp member 360 first terminal portion 364 first internal terminal 366 first external terminal 370 second terminal Portion 374 Second internal terminal 376 Second external terminal 350 Upper space 352 Lower space 354 Inlet 356 Outlet 368, 378 Housing member 380 AC power source 390 Thermocouple 392 Measuring instrument 400, 402 Evaporating means 410, 412 Breathable member 420 First electrode 430 Second electrode 440 First feed line 442, 452 Insulation sleeve 450 Second feed line 422, 432 Through hole 424 First electrode 434 Second electrode W Wafer

Claims (5)

Liquid raw material discharge means for discharging liquid raw material in the form of droplets;
An inlet for introducing the liquid material in the form of droplets;
A plate-like air-permeable member that is disposed to face the introduction port and is configured by a member having an electrical resistance that generates heat when energized;
A pair of electrodes arranged to face each other so as to sandwich the breathable member;
A power source for generating heat by energizing the breathable member through the pair of electrodes;
A delivery port for sending the raw material gas generated by vaporizing the liquid material in the form of droplets from the inlet through the inside of the breathable member that has generated heat, and
Each of the pair of electrodes is provided so as to cover the front surface and the back surface of the breathable member facing the introduction port so as to cover each surface, and a plurality of through holes are formed in the pair of electrodes. A vaporizer characterized by that. The vaporizer according to claim 1, wherein the breathable member is formed of a resistance heating element made of a porous material. The vaporizer according to claim 2 , wherein the porous material contains silicon carbide. The vaporizer according to claim 1, wherein the air-permeable member is formed of a resistance heating element made of a fiber material. A film forming apparatus including a film forming chamber for performing a film forming process on a substrate to be processed by introducing the material gas from a vaporizer that vaporizes a liquid material to generate a material gas,
The vaporizer is
Liquid raw material discharge means for discharging liquid raw material in the form of droplets;
An inlet for introducing the liquid material in the form of droplets;
A plate-like air-permeable member that is disposed to face the introduction port and is configured by a member having an electrical resistance that generates heat when energized;
A pair of electrodes arranged to face each other so as to sandwich the breathable member;
A power source for generating heat by energizing the breathable member through the pair of electrodes;
A delivery port for sending a raw material gas generated by vaporizing the liquid material in the form of liquid droplets from the inlet through the inside of the breathable member that has generated heat; and
Each of the pair of electrodes is provided so as to cover the front surface and the back surface of the breathable member facing the introduction port so as to cover each surface, and a plurality of through holes are formed in the pair of electrodes. A film forming apparatus.

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