JP2009246173A - Vaporizer and film forming device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a discharge opening for a liquid material from being closed with a reaction product of the liquid material and a carrier gas by preventing the discharge opening from being exposed the carrier gas. <P>SOLUTION: A vaporizer includes: a mist generating chamber 300A for making the liquid material into a mist; and a vaporizing chamber 300B communicating with the downstream of the mist generating chamber and vaporizing the mist of liquid material from the mist generating chamber to generate a material gas. The mist generating chamber is provided with: a liquid material supply flow passage 320 so provided in the mist generating chamber as to communicate with the discharge opening 324 for discharging the liquid material; an ultrasonic vibrator 310 having a vibration surface 316 opposed to the discharge opening for the liquid material; and a carrier gas supply flow passage 330 communicating with a blast nozzle 334 blowing a carrier gas carrying the mist of the liquid material owing to vibrations of the ultrasonic vibrator from the downstream of the discharge opening for the liquid material toward the vaporizing chamber. <P>COPYRIGHT: (C)2010,JPO&INPIT

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 using the vaporizer.

  In general, as a method of depositing various thin films composed of dielectrics, metals, semiconductors, etc., organic raw materials such as organometallic compounds are 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 organic materials used in such a CVD method are often liquid at normal temperature and pressure, it is necessary to gasify the organic materials and supply them to the film formation chamber. Therefore, normally, a liquid organic raw material is vaporized in a vaporizer to generate a raw material gas.

  For example, in the thing of the following patent document 1, the high temperature carrier gas is sprayed on the discharge outlet of a liquid raw material outflow path, The liquid raw material discharged from the discharge outlet is vaporized and raw material gas is produced | generated. In addition, in the ones described in Patent Documents 2 and 3 below, the liquid material is misted by transmitting the vibration of the ultrasonic vibrator to the liquid material discharged from the liquid material discharge unit (for example, nozzle, pipe, hole, etc.). To do. Then, a carrier gas flow is formed in the vicinity of the liquid raw material discharge port, and the mist of the liquid raw material is carried on the carrier gas flow, transferred to the heating space, and vaporized to generate the raw material gas.

Japanese Patent Application Laid-Open No. 8-200255 JP 11-16839 A JP 2001-89861 A

  However, in the conventional vaporizer in which the flow of the carrier gas is formed in the vicinity of the discharge port for discharging the liquid source as described above, depending on the type of the liquid source, the component reacts with a small amount of moisture contained in the carrier gas. Then there was a risk of solidifying. Examples of such liquid raw materials include organometallic compounds such as TEMA, TEMAZ (tetrakisethylmethylamino · zirconium) and TEMAH (tetrakisethylmethylamino · hafnium).

  In general, the vaporizer is configured to reduce the orifice diameter of the nozzle that discharges the liquid material to form liquid droplets as small as possible in order to efficiently vaporize the liquid material. Therefore, when a liquid material containing a component that easily reacts with moisture as described above is discharged from the discharge port, a product (oxide) generated by reacting with moisture contained in the carrier gas flowing in the vicinity of the liquid raw material is discharged from the discharge port or nozzle. There was also a possibility that the discharge port would be clogged up by the undesired deposits. This makes it impossible to obtain a raw material gas with a sufficient flow rate. In addition, since the nozzles must be frequently replaced and cleaned, the throughput decreases accordingly.

  Therefore, the present invention has been made in view of such problems, and the object of the present invention is to prevent the liquid material discharge port from being blocked and to obtain a high-quality raw material gas having a sufficient flow rate. An object is to provide a vaporizer and a film forming apparatus using the same.

  In order to solve the above-described problem, according to one aspect of the present invention, a misting chamber for forming a liquid raw material in a mist state is provided in communication with a downstream side of the misting chamber. A vaporization chamber that vaporizes a mist-like liquid material to generate a raw material gas, and the mist formation chamber communicates with a discharge port that discharges the liquid material provided in the mist chamber. And an ultrasonic vibrator having a vibration surface facing the liquid material discharge port, and a carrier gas for transferring the liquid material made mist by the vibration of the ultrasonic vibrator, from the liquid material discharge port. There is also provided a vaporizer characterized in that a carrier gas supply flow path communicating with a jet outlet for jetting from the downstream side toward the vaporization chamber is provided.

  In order to solve the above-described problems, according to another aspect of the present invention, a liquid source supply system for supplying a liquid source, a carrier gas supply system for supplying a carrier gas, and the source gas by vaporizing the liquid source. A film forming apparatus comprising: a vaporizer to be generated; and a film forming chamber for introducing a film from the vaporizer into a film to perform a film forming process on a substrate to be processed. A mist generating chamber, and a vaporizing chamber that is provided in communication with the downstream side of the mist forming chamber and generates a source gas by vaporizing the mist-like liquid material from the mist forming chamber, The mist chamber includes a liquid material supply channel that is provided in the mist chamber and communicates with a discharge port that discharges the liquid material, and an ultrasonic vibrator having a vibration surface that faces the liquid material discharge port. , Mistakes due to vibration of the ultrasonic transducer And a carrier gas supply channel that communicates with a jet outlet that jets a carrier gas that transports the liquid source into the vaporization chamber from the downstream side of the liquid source discharge port toward the vaporization chamber. Is provided.

  According to the vaporizer or the film forming apparatus of the present invention, the carrier gas is ejected from the ejection port through the carrier gas supply channel, and the liquid material is ejected from the ejection port through the liquid material supply channel. When discharged toward the vibration surface of the ultrasonic vibrator, the liquid raw material can be made into a mist by the vibration energy of the vibration surface. This mist-like liquid raw material is transferred to the vaporization chamber by the flow of the carrier gas. At this time, since the carrier gas is ejected from the downstream side of the liquid source discharge port toward the vaporization chamber, the liquid source discharge port is not exposed to the carrier gas. For this reason, even if the carrier gas contains a slight amount of moisture, the moisture and the liquid source do not react to form a reaction product, thereby preventing the liquid source outlet from being blocked. It is possible to obtain a high-quality raw material gas with a sufficient flow rate.

  In this case, the carrier gas ejection port may be provided, for example, on the downstream side of the liquid material ejection port. According to this, the carrier gas can be ejected from the downstream side of the liquid material discharge port toward the vaporization chamber. As a result, the liquid material discharge port is not exposed to the carrier gas.

  Also, an outer peripheral surface of the shielding member is provided by providing a cylindrical shielding member that surrounds and shields the outside of the liquid material discharge port, and that the carrier gas jet port is provided outside the shielding member. The carrier gas flows between the inner wall of the mist chamber and the inner wall of the mist chamber, and the carrier gas is ejected from the periphery of the shielding member where the mist-shaped liquid material is discharged toward the vaporization chamber. You may make it do.

  According to this, the liquid raw material is mist-shaped in the shielding member and discharged (overflows) from the end of the shielding member. At this time, since the carrier gas is ejected from around the end of the shielding member, the mist-like liquid material is efficiently transferred to the vaporization chamber along the carrier gas flow. Further, since the carrier gas passes outside the shielding member, the liquid source discharge port inside the shielding member is not exposed to the carrier gas.

  In this case, it is preferable that the inner wall of the mist chamber is gradually throttled toward the lower end of the shielding member, and a throttle portion is formed in the vicinity of the end of the shielding member from which the carrier gas is ejected. According to this, since the flow velocity of the carrier gas flowing outside the shielding member can be increased, the pressure in the vicinity of the end of the shielding member becomes lower than the pressure in the vicinity of the discharge port. Mist liquid raw material can be actively extracted. Therefore, the mist-like liquid source can be transferred to the vaporization chamber more efficiently, and the source gas can be generated efficiently.

  In addition, it is preferable that the ultrasonic vibrator is arranged so that the vibration surface faces downward, and the liquid material is discharged upward from the discharge port. According to this, the liquid raw material does not become excessively supplied by its own weight, and the liquid raw material that has been made mist on the vibration surface of the ultrasonic vibrator can be dropped by its own weight and placed on the carrier gas flow. As a result, the carrier gas can be efficiently transferred toward the vaporization chamber.

  The vaporization chamber has a plate-like shape that divides the vaporization chamber into an upstream space that communicates with the introduction port and a downstream space that introduces the mist-like liquid material from the mist vaporization chamber. A vaporizing member comprising a vaporizing member, wherein a plurality of through-holes communicating with the upstream space and the downstream space along the circumferential direction are formed in a peripheral portion of the vaporizing member, and the vaporizing member that heats the vaporizing member Part heater, a mist trap part made of a breathable plate-like air-permeable member provided so as to close a space downstream of the vaporization part, and a mist trap part heating for heating the mist trap part It is preferable to include a heater and a delivery port provided on the downstream side of the mist trap part, which is heated and vaporized in the heated mist trap part, and that feeds the raw material gas that has passed through these parts to the outside.

  According to this, the liquid raw material made into mist in the misting chamber is transferred to the vaporizing chamber through the inlet. Then, first, it vaporizes in contact with the vaporization part heated by the vaporization part heater. At this time, even if there is a mist-like liquid raw material remaining without being vaporized, the mist-like liquid raw material flows downstream through the plurality of through holes together with the vaporized raw material gas. And it is trapped and vaporized by the mist trap part heated by the mist trap part heater. The raw material gas generated in this way is sent to the outside from the delivery port.

  At this time, for example, a straight particle having a relatively large particle size can be vaporized in the upstream vaporization section, and the remaining fine mist liquid material can be vaporized in the downstream mist trap section. Thus, since the mist-like liquid material can be vaporized by the two-stage structure of the vaporization part and the mist trap part, all the mist-like liquid material vaporized in the misting room can be efficiently converted into the vaporization room. It is possible to generate a high-quality and sufficient flow rate of raw material gas that does not contain unvaporized components.

  According to the present invention, the liquid material discharged from the discharge port can be misted without supplying the carrier gas in the vicinity of the discharge port of the liquid material, and the carrier gas is disposed downstream of the discharge port of the liquid material. By forming this flow, the misted liquid raw material can be transferred to the vaporization section. As a result, it is possible to prevent deposits from being accumulated and clogged at the liquid material discharge port, and to obtain a high-quality raw material gas having a sufficient flow rate.

  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 such as a semiconductor wafer (hereinafter simply referred to as “wafer”) W by a CVD method. For example, a liquid source containing Zr A liquid source supply source 110 for supplying a gas, a carrier gas supply source 120 for supplying an inert gas such as Ar as a carrier gas, and a vapor source for generating a source gas by vaporizing a liquid source supplied from the liquid source supply source 110 A deposition chamber 200 for forming, for example, a ZrO ₂ film on the wafer W using the source gas generated by the vaporizer 300, and a controller 140 for controlling each part of the deposition apparatus 100.

  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 rate control valve 114, the carrier gas supply pipe 122 is provided with a carrier gas flow rate control valve 124, and the source gas supply pipe 132 is provided with a source gas flow rate control valve 134. Is provided. 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 configured such that their opening degrees are adjusted by a control signal from the control unit 140. The control unit 140 measures the flow rate of the liquid raw material flowing through the liquid raw material supply pipe 112, the flow rate of the carrier gas flowing through the carrier gas supply pipe 122, and the flow rate of the raw material gas flowing through the raw material gas supply pipe 132. Accordingly, it is preferable to output a control signal.

  The liquid source supply source 110 stores, for example, a Zr-based or Hf-based organometallic compound as a liquid source, and supplies the liquid source to the vaporizer 300 through the liquid source supply pipe 112. As these organometallic compounds, for example, TEMAZ (tetrakisethylmethylamino · zirconium) and TEMAH (tetrakisethylmethylamino · hafnium) are used.

Other examples of Zr-based and Hf-based organometallic compounds include tetratertiary butoxy-zirconium [Zr (Ot-Bu) ₄ ], tetrakismethoxymethylpropoxy-zirconium [Zr (MMP) ₄ ], tetra-tertiary. Butoxy hafnium [Hf (Ot-Bu) ₄ ], tetradiethylamino hafnium [Hf (NEt ₂ ) ₄ ], tetrakismethoxymethylpropoxy hafnium [Hf (MMP) ₄ ], tetradimethylamino hafnium [Hf (NMe _{2) 4} ], tetramethylethylamino hafnium [Hf (NMeEt) ₄ ], tetrakistriethylsiloxy hafnium [Hf (OSiEt ₃ ) ₄ ].

In addition, organometallic compounds other than Zr and Hf may be used. Examples include pentaethoxy tantalum [Ta (O-Et)], tetraethoxy silicon [Si (OEt) ₄ ], tetradimethylamino silicon [Si (NMe ₂ ) ₄ ], disethyl cyclopentadienyl. ruthenium [Ru _(EtCp) 2], tertiary amyl imido tri dimethylamide tantalum _{[Ta (Nt-Am) (} NMe 2) 3], trisdimethylaminosilane [HSi _{(NMe 2) 3]} may be mentioned.

  Some of these organometallic compounds are solid at normal temperature and pressure. Such an organometallic compound is dissolved in an organic solvent such as octane to be liquefied and supplied to the vaporizer 300.

  The film formation chamber 200 includes, for example, a substantially cylindrical side wall member 210, a top wall member 212 that closes an upstream opening of the side wall member 210, and a bottom wall member 214 that closes a downstream opening of the side wall member 210. In the internal space surrounded by the side wall member 210, the top wall member 212, and the bottom wall member 214, a susceptor 222 on which the wafer W is placed horizontally is provided. The side wall member 210, the top wall member 212, and the bottom wall member 214 are made of a metal such as Al 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 member 214 of the film forming chamber 200, and an exhaust unit 232 is connected to the exhaust port 230. The inside of the film formation chamber 200 can be adjusted to a predetermined degree of vacuum by the exhaust unit 232.

  A shower head 240 is attached to the top wall member 212 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 in 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, the source gas is supplied from the vaporizer 300 to the film forming chamber 200 as follows. The liquid source is supplied from the liquid source supply source 110 via the liquid source supply pipe 112 to the vaporizer 300 (here, a mist chamber 300A described later), and from the carrier gas supply source 120 via the carrier gas supply pipe 122. When the carrier gas is supplied, the liquid raw material is misted, and this mist-like liquid raw material rides on the flow of the carrier gas and is led to a downstream vaporization chamber (described later). In this vaporization chamber, the mist-like liquid raw material is heated and vaporized to generate a raw material gas. The source gas generated in the vaporizer 300 in this way is supplied to the film forming chamber 200 via the source gas supply pipe 132, and a desired process is performed on the wafer W in the film forming chamber 200.

  By the way, when the liquid raw material is misted in the vaporizer 300, if the liquid raw material is discharged from a nozzle having a small orifice diameter and a carrier gas is allowed to flow in the vicinity of the nozzle outlet as in the prior art, the liquid raw material is For example, in the case of an organometallic compound such as TEMAZ or TEMAH, there is a risk that the organometallic compound reacts with a small amount of moisture contained in the carrier gas, and the reaction product accumulates in the nozzle, which eventually closes the nozzle. It was.

In this case, the flow rate of the liquid source is reduced, and accordingly, the flow rate of the source gas supplied to the film forming chamber 200 is insufficient. For this reason, a desired film formation rate cannot be obtained when, for example, an HfO ₂ film is formed on the wafer W. Also, since the nozzle replacement work and cleaning work are required before the nozzle discharge port is blocked, the throughput is reduced accordingly.

  Therefore, in the vaporizer according to the first embodiment, it is possible to prevent the nozzle from being blocked by forming the flow of the carrier gas from the discharge side of the nozzle that discharges the liquid raw material toward the vaporization chamber from the downstream side. Is.

(Configuration example of vaporizer according to the first embodiment)
Hereinafter, 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 divided into a mist-forming chamber 300A in which a liquid material is mist-like, and a mist-like liquid material introduced from the mist-making chamber 300A in communication with the mist-making chamber 300A by heating. It comprises a vaporization chamber 300B that vaporizes to produce a raw material gas.

  In these, the mist chamber 300A and the vapor chamber 300B are constituted by a block-shaped casing 301 as shown in FIG. 2, for example. The housing 301 is made of a metal such as Al or stainless steel. The housing 301 is formed with an insertion hole 303 into which a horn portion 314 of an ultrasonic transducer 310 (to be described later) is inserted, an internal space 302 in the mist chamber 300A, and an internal space 306 in the vaporization chamber 300B. The insertion hole 303 is formed in a tapered shape whose diameter gradually decreases from the upper end surface of the housing 301, and the lower end thereof communicates with the internal space 302 of the mist chamber 300A.

  The inner space 302 of the mist chamber 300A is gradually enlarged in diameter from the lower end of the insertion hole 303 to form an enlarged diameter portion 304 having a constant diameter. The lower end of the enlarged diameter portion 304 communicates with the internal space 306 of the vaporizing chamber 300B through the introduction port 305. The internal space 306 of the vaporization chamber 300B is gradually expanded in diameter from the introduction port 305 toward the downstream side, and communicates with the cylindrical space. Each component is provided in these internal spaces 302 and 306, and the mist chamber 300A and the vaporization chamber 300B are configured.

  First, a configuration example of the mist chamber 300A will be described. The misting chamber 300A is provided by being inserted into the insertion hole 303 of the housing 301, and discharges the liquid source to the ultrasonic vibrator 310 for misting the liquid source and the vibration surface 316 of the ultrasonic vibrator 310. A liquid source supply channel 320 that communicates with the discharge port 324, and a carrier gas that supplies a carrier gas for transferring the misted liquid source from the misting chamber 300A to the vaporization chamber 300B from the downstream side of the discharge port 324. A carrier gas supply channel 330 that communicates with the jet port 334 is provided. A liquid source supply pipe 112 is connected to the liquid source supply flow path 320, and a carrier gas supply pipe 122 is connected to the carrier gas supply flow path 330.

  The ultrasonic transducer 310 is, for example, a horn type or a Langevin type transducer in which a metal horn unit 314 is connected to a piezoelectric element 312. A high frequency power source (not shown) is electrically connected to the piezoelectric element 312. The ultrasonic transducer 310 is attached to the upper portion of the mist chamber 300A with the horn portion 314 inserted into the insertion hole 303. The vibration surface 316 at the tip of the horn unit 314 is disposed so as to face the internal space 302 downward.

  The liquid raw material supply channel 320 is formed horizontally from the side surface of the casing 301, extends through the inner surface of the enlarged diameter portion 304 to the center thereof, and is bent upward. A portion of the liquid source supply flow path 320 that extends from the inner surface of the enlarged diameter portion 304 to the upper side of the enlarged diameter portion 304 is a liquid source discharge nozzle 322 as a liquid source discharge portion attached to the inner surface of the enlarged diameter portion 304. Is formed inside. The discharge port 324 at the tip of the liquid source supply flow path 320, that is, the tip of the liquid source discharge nozzle 322 faces the vibration surface 316 of the horn part 314 of the ultrasonic transducer 310. As a result, the liquid material is discharged from the discharge port 324 of the liquid material discharge nozzle 322 toward the vibration surface 316.

  The positional relationship between the discharge port 324 of the liquid material discharge nozzle 322 and the vibration surface 316 of the ultrasonic transducer 310 will be described with reference to FIG. FIG. 3 is an enlarged cross-sectional view of the discharge port 324 and the vibration surface 316. As shown in FIG. 3, the liquid material 116 discharged from the discharge port 324 of the liquid material discharge nozzle 322 becomes hemispherical due to surface tension. The liquid raw material discharge nozzle 322 and the ultrasonic vibrator 310 are arranged so that the vibrating surface 316 of the vibrating horn unit 314 collides with the liquid raw material 116 before the hemispherical liquid raw material 116 is detached from the discharge port 324. Has been. However, even when the horn portion 314 vibrates and the vibration surface 316 is closest to the discharge port 324 of the liquid material discharge nozzle 322, the gap G is not formed so that the vibration surface 316 contacts the discharge port 324 and is not blocked. Positioned to remain. Thus, vibration energy is given to the liquid material 116 discharged from the discharge port 324 of the liquid material discharge nozzle 322 from the vibration surface 316 of the horn unit 314, and a mist-like liquid material is generated.

  At this time, in order to generate a sufficient amount of mist-like liquid material, a certain amount of liquid material 116 is discharged from the discharge port 324 of the liquid material discharge nozzle 322, and the liquid material 116 is supplied with the horn portion 314. It is necessary to make the vibration surface 316 collide. For that purpose, it is preferable that the vibration stroke Sta of the vibration surface 316 of the horn part 314 is large. In order to increase the vaporization efficiency in the vaporization chamber 300B, it is preferable to increase the vibration frequency of the horn unit 314 to generate a finer mist-like liquid material.

  If the liquid material is directly supplied to the vibration surface of the piezoelectric element 312 to make a mist, it is necessary to adjust the vibration stroke of the piezoelectric element 312 and the frequency to be high. In this case, not only the power consumption of the piezoelectric element 312 is increased, but the piezoelectric element 312 is heated, and there is a possibility that continuous operation cannot be performed.

  On the other hand, according to the ultrasonic transducer 310 according to the present embodiment, since the horn unit 314 is connected to the piezoelectric element 312, even if the vibration stroke of the piezoelectric element 312 is reduced, the vibration of the horn unit 314 is reduced. A large vibration stroke can be obtained at the surface 316.

  Here, the operation of the ultrasonic transducer 310 will be described with reference to the drawings. FIG. 4 is a schematic diagram for explaining the operation of the ultrasonic transducer. As shown in FIG. 4, the horn unit 314 is configured so that its length is ½ of the wavelength λ of the traveling wave. As a result, the horn unit 314 resonates with the piezoelectric element 312, and the maximum vibration stroke can be obtained at the vibration surface 316 of the horn unit 314. Further, in order to obtain a larger vibration stroke, the ultrasonic vibrator 310 is formed with a horn portion 314 tapered. When the transverse area of the piezoelectric element 312 constituting the ultrasonic transducer 310 is Sb, the vibration stroke is Stb, and the surface area of the vibration surface 316 of the horn unit 314 is Sa, the vibration stroke Sta on the vibration surface 316 of the horn unit 314 is It can represent with following Numerical formula (1).

Sta = (Sb / Sa) × Stb
... (1)

  As described above, the horn portion 314 is tapered, and the vibration surface 316 has a surface area Sa that is significantly smaller than the transverse area Sb of the piezoelectric element 312. Therefore, as is clear from the above formula (1), the vibration surface 316 can obtain a vibration stroke Sta far larger than the vibration stroke Stb of the piezoelectric element 312. According to such an ultrasonic transducer 310, even if the vibration stroke Stb of the piezoelectric element 312 is kept small, the vibration surface 316 of the horn unit 314 can be vibrated with a large vibration stroke Sta. Therefore, the vibration frequency of the piezoelectric element 312 can be increased while suppressing power consumption and heat generation of the piezoelectric element 312. As a result, a sufficient amount of an extremely fine mist-like liquid material can be generated.

  The diameter of the discharge port 324 of the liquid source discharge nozzle 322 is a hemispherical shape when the target amount of liquid source supplied to the vibration surface 316 of the horn unit 314 of the ultrasonic vibrator 310 or the discharge port 324 is discharged. It is determined according to the target size of the liquid raw material. In order to reliably vaporize the liquid raw material in the vaporizer 300, it is preferable to supply a fine mist-like liquid raw material to the vaporizing chamber 300B. For this purpose, the liquid raw material discharged from the discharge port 324 of the liquid raw material discharge nozzle 322 is preferable. A smaller amount or size is advantageous. Therefore, it is preferable that the diameter of the discharge port 324 is also small. However, if the amount or size of the liquid material becomes too small, the flow rate of the mist-like liquid material that can be supplied to the vaporization chamber 300B is insufficient, and as a result, it may not be possible to generate a material gas with a sufficient flow rate. . In consideration of these points, it is preferable to determine the diameter of the discharge port 324.

  As a constituent material of the liquid raw material discharge nozzle 322, a synthetic resin such as a polyimide resin resistant to an organic solvent or a metal such as stainless steel or titanium is preferable. If the liquid raw material discharge nozzle 322 is made of synthetic resin, heat can be prevented from being conducted from the surroundings to the liquid raw material before being discharged. In particular, the use of polyimide resin makes it difficult for liquid raw material residues (precipitates) to adhere to the liquid raw material discharge nozzle 322, so that the effect of preventing nozzle clogging can be enhanced.

  Next, a configuration example of the carrier gas supply channel 330 will be described with reference to FIG. 2 again. The carrier gas supply channel 330 includes a buffer chamber 336 formed in the casing 301 so as to surround the periphery of the liquid material discharge nozzle 322, and a carrier for introducing the carrier gas from the carrier gas supply pipe 122 into the buffer chamber 336. The gas introduction flow path 332 and a plurality of carrier gas ejection ports 334 for ejecting the carrier gas from the buffer chamber 336 into the mist chamber 300A. Each carrier gas outlet 334 is annularly arranged around the liquid source discharge nozzle 322, and is formed so as to jet the carrier gas from the downstream side of the discharge port 324 of the liquid source discharge nozzle 322 toward the vaporization chamber 300B. ing.

  According to such a carrier gas supply flow path 330, the carrier gas from the carrier gas supply pipe 122 flows into the buffer chamber 336 through the carrier gas introduction flow path 332 and diffuses. The carrier gas in the buffer chamber 336 is ejected from each carrier gas ejection port 334 toward the lower vaporization chamber 300B.

  In particular, each carrier gas ejection port 334 in the present embodiment is disposed downstream of the ejection port 324 of the liquid source ejection nozzle 322 and opens toward the vaporization chamber 300B. As a result, a carrier gas flow from the downstream side of the discharge port 324 of the liquid source discharge nozzle 322 toward the vaporization chamber 300B is formed. For this reason, the discharge port 324 of the liquid source discharge nozzle 322 is not exposed to the carrier gas.

  Next, a configuration example of the vaporizing chamber 300B will be described with reference to the drawings. The vaporization chamber 300B is a disc that divides an inlet 305 for introducing the mist-like liquid material from the mist chamber 300A, and an internal space 306 connected to the inlet 305 into an upstream space and a downstream space. Provided with a vaporizing part 340 made of a gas-like vaporizing member 341, a mist trap part 350 made of a gas-permeable member provided to close the downstream side thereof, and a raw material gas delivery port 360 provided on the downstream side thereof. .

  The vaporizing member 341 constituting the vaporizing unit 340 is made of a metal such as Al or stainless steel, for example, and is heated at a predetermined temperature. A plurality of through-holes 342 communicating the upstream space and the downstream space are formed along the circumferential direction of the peripheral portion of the vaporizing member 341. These through holes 342 are formed in a region outside the surface of the vaporizing member 341 that is outside the region facing the inlet 305 from which the mist-like liquid material is discharged downward from the misting chamber 300A. .

  Further, a vaporizing part heater 344 is embedded in the vaporizing part 340. The vaporization part heater 344 is composed of, for example, a resistance heater, and generates heat when electric power is supplied from an external power source (not shown), so that the entire vaporization part 340 is higher than the vaporization temperature of the liquid material, for example. It can be heated to a predetermined temperature.

  The mist trap part 350 is comprised by the air permeability member 351 which has the air permeability which permeate | transmits without passing mist-like liquid raw material, and lets the raw material gas obtained by vaporizing this. As such a gas-permeable member 351, it is preferable to employ a material having a finer diameter than the mist diameter of the liquid raw material. Moreover, as a constituent material of the air-permeable member 351, a material having a high thermal conductivity and a characteristic that the temperature is likely to rise is preferable. Examples of such a condition that can be satisfied include metals such as stainless steel having a porous structure or a mesh structure. In addition, ceramics or plastics having high thermal conductivity may be used.

  Further, a mist trap heater 352 is provided outside the casing 301 of the vaporizing chamber 300B so as to surround the outer peripheral surface thereof. The mist trap part heater 352 is composed of, for example, a resistance heater, and generates heat when power is supplied from an external power source (not shown), and the mist trap part is heated via the casing 301 of the vaporization chamber 300B. 350 can be heated. As described above, since the casing 301 is made of a metal having high thermal conductivity, heat can be efficiently transferred from the casing 301 to the mist trap unit 350. Thereby, the mist trap part 350 can be heated to a predetermined temperature higher than the vaporization temperature of the liquid material, for example.

  The mist trap heater 352 is not limited to the resistance heater, but may be a radiant heater that heats the casing 301 or the mist trap 350 with radiant heat, such as a carbon heater, a halogen heater, or a nichrome heater. It may be. Further, the mist trap part heater 352 is mainly disposed around the mist trap part 350 to heat the mist trap part 350. Heating may be performed including the internal space 306.

(Operation of the deposition system)
Next, the operation of the film forming apparatus 100 according to the present embodiment will be described. The film forming apparatus 100 is configured such that each unit is controlled by the control unit 140 to operate. In generating the raw material gas by the vaporizer 300, the vaporizer heating heater 344 and the mist trap heater 352 of the vaporizer 300 are heated in advance to heat the vaporizer 340 and the mist trap 350. At this time, the temperatures of the vaporization unit 340 and the mist trap unit 350 are adjusted and held at a temperature (for example, 100 to 300 ° C.) higher than the vaporization temperature of the liquid raw material, for example.

  First, the control unit 140 controls the liquid raw material flow rate control valve 114 so that a liquid raw material having a predetermined flow rate is supplied from the liquid raw material supply source 110 to the mist chamber 300A of the vaporizer 300 via the liquid raw material supply pipe 112. Adjust the opening. At the same time, the opening degree of the carrier gas flow control valve 124 is adjusted so that the carrier gas having a predetermined flow rate is supplied from the carrier gas supply source 120 to the mist chamber 300A of the vaporizer 300 via the carrier gas supply pipe 122. To do.

  In addition, high frequency power (for example, 2.4 MHz) is supplied from a high frequency power source (not shown) to the piezoelectric element 312 of the ultrasonic transducer 310 provided in the vaporizer 300. As a result, the vibration surface 316 of the horn unit 314 vibrates with a predetermined stroke in the range of several μm to several tens of μm, for example.

  The liquid source supplied to the mist chamber 300A of the vaporizer 300 via the liquid source supply pipe 112 reaches the liquid source discharge nozzle 322 via the liquid source supply channel 320 and is discharged from the discharge port 324. The liquid material discharged from the discharge port 324 becomes hemispherical due to surface tension (see FIG. 3). At this time, since the ultrasonic transducer 310 vibrates, the hemispherical liquid material discharged from the discharge port 324 is not separated from the discharge port 324 before the vibration surface of the horn part 314 of the ultrasonic transducer 310 is vibrated. It collides with 316 and becomes mist.

  The liquid material thus formed in a mist form is diffused around the liquid material discharge nozzle 322, and then falls under gravity, that is, toward the vaporizing chamber 300B. In addition, an exhaust unit 232 is connected to the film forming chamber 200 disposed on the downstream side of the vaporizer 300, and when the liquid material is introduced into the vaporizer 300, the exhaust unit 232 is disposed inside the film forming chamber 200. Is maintained at a predetermined degree of vacuum. For this reason, the internal spaces 302 and 306 of the vaporizer 300 are in a positive pressure state with respect to the inside of the film formation chamber 200, and the mist-like liquid material flows toward the vaporization chamber 300B also by this pressure difference.

  On the other hand, the carrier gas supplied to the mist chamber 300 </ b> A of the vaporizer 300 through the carrier gas supply pipe 122 flows into the buffer chamber 336 from the carrier gas introduction channel 332. Then, the carrier gas in the buffer chamber 336 is ejected from each carrier gas ejection port 334 into the mist chamber 300A.

  Since each carrier gas outlet 334 opens toward the lower vaporization chamber 300B, the carrier gas ejected from each carrier gas outlet 334 is vaporized chamber 300B as shown by an arrow in FIG. A flow toward the surface of the inner vaporization section 340 is formed. Moreover, each carrier gas outlet 334 is located closer to the vaporization chamber 300 </ b> B than the discharge port 324 of the liquid source discharge nozzle 322. Therefore, the discharge port 324 of the liquid source discharge nozzle 322 is not exposed to the carrier gas.

  Further, since the carrier gas is not supplied between the vibration surface 316 of the horn portion 314 of the ultrasonic vibrator 310 and the discharge port 324 of the liquid material discharge nozzle 322, the flow of the carrier gas affects the mist formation of the liquid material. There is no effect. The amount and particle size of the mist of the liquid material is adjusted stably and with good reproducibility by setting the distance between the vibration surface 316 and the discharge port 324, the vibration stroke amount of the horn unit 314, the vibration frequency, and the like. can do.

  The liquid raw material thus made into a fine mist shape falls by its own weight, and rides on the flow of the carrier gas on the way and is introduced into the vaporizing chamber 300B from the downstream inlet 305 via the internal space 302. The vaporization unit 340 is reached. As described above, the vaporization unit 340 has a plurality of regions only in the region outside the position corresponding to the ejection direction (indicated by the arrow in FIG. 2) of the carrier gas ejected from the carrier gas ejection port 334 in the entire surface. A through hole 342 is provided. For this reason, most of the mist-like liquid raw material introduced into the vaporizing chamber 300 </ b> B comes into contact with the surface of the vaporizing unit 340.

  Since the vaporization unit 340 is heated to a predetermined temperature by the vaporization unit heater 344 in advance, the mist-like liquid source that comes into contact with the surface is instantaneously vaporized to generate a source gas.

  By the way, among the mist-like liquid raw materials, for example, those whose particle sizes have become larger due to contact with each other in the middle, for example, have higher straightness in the direction of gravity than fine mist, The surface of the vaporization part 340 is contacted with a higher probability. Accordingly, a mist-like liquid material having a particularly large particle size is efficiently vaporized by the vaporization section 340 without passing through the through holes 342, and a raw material gas is generated.

  As described above, since the internal spaces 302 and 306 of the vaporizer 300 are in a positive pressure state with respect to the inside of the film forming chamber 200, the liquid raw material (raw material gas) vaporized on the surface of the vaporizing unit 340 is a carrier gas. At the same time, it passes through each through hole 342 and reaches the mist trap portion 350 disposed further downstream.

  Further, even if the mist-like liquid material contacts the surface of the heated vaporizing section 340, for example, if the particle size is too large or if it reaches a single location, a small amount of the liquid material is used. However, the gas may not be vaporized and remains in a mist state, and may pass through the through-holes 342 and reach the mist trap part 350 on the flow of the source gas and the carrier gas.

  In addition, among the mist-like liquid raw materials introduced into the vaporizing chamber 300B from the mist vaporizing chamber 300A, those having a very small size are scattered outside the carrier gas flow path, and the vaporizing section 340 May pass through each through-hole 342 without contacting the surface.

  Thus, what reaches the mist trap part 350 through each through-hole 342 of the vaporization part 340 includes not only the raw material gas and the carrier gas but also a mist-like liquid raw material that has not yet been vaporized. . Of these, the source gas and the carrier gas pass through without being trapped in the mist trap portion 350.

  On the other hand, the unvaporized mist-like liquid material is once trapped in the mist trap unit 350. At this time, the mist trap part 350 is adjusted to a predetermined temperature higher than the vaporization temperature of the liquid raw material by the mist trap part heater 352. Therefore, the mist-like liquid material trapped in the mist trap part 350 is instantly vaporized to become a raw material gas and passes through the mist trap part 350.

  Since the internal space 306 of the vaporizing chamber 300B is heated by the mist trap heater 352, a part of the unvaporized mist-like liquid raw material that has passed through each through-hole 342 of the vaporizing unit 340 It can be vaporized while flying through space 306.

  Thus, the raw material gas and carrier gas that have passed through the mist trap part 350 and the liquid raw material (raw material gas) once trapped and vaporized in the mist trap part 350 are sent to the raw material gas supply pipe 132 via the outlet 360. The

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 vaporizer 300 according to the first embodiment, the carrier gas is ejected from the ejection port 334 through the carrier gas supply channel 530 in the mist chamber 300A, and the liquid source is supplied to the liquid source supply flow. When discharged from the discharge port 324 of the liquid material discharge nozzle 322 toward the vibration surface 316 of the ultrasonic vibrator 310 through the path 320, the liquid material can be made into a mist shape by the vibration energy of the vibration surface 316. This mist-like liquid raw material is transferred to the vaporization chamber 300B by the flow of the carrier gas.

  At this time, since the carrier gas is ejected from the downstream side of the liquid source discharge port 316 toward the vaporization chamber 300B, the liquid source discharge port 324 is not exposed to the carrier gas. For this reason, even if the carrier gas contains a small amount of moisture, the moisture and the liquid raw material do not react to form a reaction product, and the reaction product is deposited in the liquid raw material discharge nozzle 322. There is no need to do. Therefore, it is possible to prevent the liquid material discharge port 324 from being clogged, and it is possible to generate a high-quality material gas having a sufficient flow rate. In addition, the work of replacing or cleaning the liquid source discharge nozzle 322 and the like over a long period of time becomes unnecessary, and thus the throughput in the film forming apparatus 100 can be improved.

  Further, in the vaporization chamber 300B, the mist-like liquid material is vaporized by a two-stage arrangement of an upstream vaporization section 340 and a downstream mist trap section 350. According to this, for example, a straight particle having a relatively large particle size can be vaporized in the upstream vaporization section, and the remaining fine mist liquid material can be vaporized in the downstream mist trap section. . As a result, all of the mist-like liquid material vaporized in the mist chamber can be efficiently vaporized in the vapor chamber, and a high-quality and sufficient flow rate of raw material gas that does not contain unvaporized components is generated. It can be supplied to the membrane chamber 200.

(Specific configuration example of vaporizer)
Next, a more specific configuration example of the vaporizer 300 according to the present embodiment will be described in detail with reference to the drawings. FIG. 5 is a longitudinal sectional view showing a specific configuration example of the vaporizer 300. It should be noted that parts having the same functions as those of the vaporizer 300 shown in FIG.

  In the vaporizer 300 shown in FIG. 5, the housing 301 is divided into an upper housing 400, an intermediate housing 402, and a lower housing 404, which are combined. In the upper housing 400, the intermediate housing 402, and the lower housing 404, an internal space 302 of the mist chamber 300A and an internal space 306 of the vaporization chamber 300B are formed.

  Specifically, an insertion hole 303 for the ultrasonic transducer 310 is formed on the upper surface of the upper casing 400. The intermediate housing 402 is formed with an enlarged space 304 from the downstream side of the insertion hole 303 as an internal space 302 of the mist chamber 300A, and in the expanded portion 304 of the internal space 306 of the vaporization chamber 300B. An upstream space defined by the vaporizing unit 340 from the communicating inlet 305 is formed. Further, the lower housing 404 is formed with a downstream space divided by the vaporization unit 340 in the internal space 306 of the vaporization chamber 300B.

  These upper casing 400, middle casing 402, and lower casing 404 are hermetically coupled with bolts. Specifically, an upper flange 414 and a lower flange 416 are respectively provided on the upper and lower sides of the intermediate housing 402, and the upper housing 400 is fixed to the upper flange 414 with a plurality of bolts 420. The lower housing 404 is fixed to the lower flange 416 with a plurality of bolts 430 with a disk-shaped vaporizing member 341 constituting the vaporizing unit 340 interposed therebetween.

  A seal member 418 is interposed between the upper casing 400 and the intermediate casing 402 for sealing, and a sealing member 432 is interposed between the intermediate casing 402 and the vaporizing member 341 for sealing. A seal member 434 is interposed between the member 341 and the lower housing 404 for sealing. As these seal members 418, 432, and 434, for example, O-rings are used. Thereby, the airtightness of the internal spaces 302 and 306 of the upper casing 400, the intermediate casing 402, and the lower casing 404 is maintained.

  In the upper housing 400, a counterbore is formed at the upper end of the insertion hole 303. In the ultrasonic transducer 310, the horn portion 314 is inserted into the insertion hole 303, and the flange portion 318 is inserted into the counterbore so that the vibration surface 316 at the tip of the horn portion 314 is positioned. In other words, the vibration surface 316 of the ultrasonic transducer 310 is disposed so as to penetrate the lower end of the insertion portion 303 and face the internal space 302, and between the discharge port 324 of the liquid source discharge nozzle 322 facing the vibration surface 316. Are positioned so as to form a predetermined gap. A ring-shaped stopper plate 410 that stops the flange portion 318 is screwed to the upper surface of the upper housing 400.

  The intermediate casing 402 is formed with the liquid source supply channel 320 and the carrier gas supply channel 330, respectively. The liquid material discharge nozzle 322 is arranged upward in the center of the internal space 302 of the intermediate housing 402.

  Between the intermediate housing 402 and the lower housing 404, the plate-shaped vaporizing member 341 constituting the vaporizing unit 340 is interposed as described above. When the AA cross section shown in FIG. 5 is viewed from above, the vaporizing member 341 is, for example, as shown in FIG. That is, the vaporization part heater 344 is embedded in the vaporization member 341. The vaporizing section heater 344 is constituted by, for example, a rod-shaped resistance heating heater, and is inserted further through the substantial center of the vaporizing member 341. Thereby, the whole vaporization member 341 can be heated.

  Further, a plurality of through holes 342 are formed in the vaporizing member 341 along the circumferential direction at the peripheral edge outside the inlet 305 shown in FIG. 5 into which the mist liquid material is introduced from the mist generating chamber 300A. Has been. Accordingly, among the mist-like liquid materials from the mist chamber 300A, a mist-like liquid material having a particularly large particle size is highly likely to fall directly under its own weight, so that the surface of the heated vaporization member 341 is heated. Of these, it falls to the central region where the through hole 342 is not formed and vaporizes. The source gas thus vaporized flows into the lower housing 404 through the through hole 342.

  An internal space 306 formed in the lower housing 404 is divided into an upper bottomed hole 307 that opens to the upper surface and a lower bottomed hole 308 that opens to the lower surface, and between the upper bottomed hole 307 and the lower bottomed hole 308. A plurality of through holes 424 that penetrate from the upper bottomed hole 307 to the lower bottomed hole 308 are formed in the thick portion 422. When the BB cross section shown in FIG. 5 is viewed from above, these through holes 424 are evenly provided over the entire thickness portion 422 as shown in FIG. 7, for example.

  A mist trap portion 350 is attached in the lower bottomed hole 308 so as to close each through hole 424. Specifically, a disc-shaped breathable member 351 constituting the mist trap portion 350 is attached to the lower surface of the thickness portion 422. Here, the peripheral part of the air-permeable member 351 is fixed by pressing it with a ring-shaped attachment member 426 and screwing it.

  Therefore, the mist-like liquid raw material that could not be vaporized by the vaporizing unit 340 also enters each through-hole 424 together with the raw material gas that has already been vaporized, and always comes into contact with the mist trap unit 350. As a result, the mist-like liquid material that could not be vaporized is also trapped in the mist trap portion 350 and vaporized. The raw material gas thus generated passes through the mist trap part 350 and is sent from the outlet 360 to the raw material gas supply pipe 132 through the lower bottomed hole 308.

  A bottom plate 408 is attached to the lower surface of the lower housing 404, and the open end of the lower bottomed hole 308 is closed by the bottom plate 408. In the center of the bottom plate 408, a delivery port 360 communicating with the internal space 306 of the vaporization chamber 300B is formed, and the source gas supply pipe 132 is connected to the delivery port 360.

  A mist trap heater 352 is provided outside the lower housing 404 so as to surround the outer periphery of the lower housing 404. When the mist trap part heater 352 generates heat, the entire lower casing 404 is heated, and the mist trap part 350 is efficiently heated via the side wall of the lower casing 404, the attachment member 426, the thickness part 422, and the like. That is, since the mist trap part 350 adheres to the heated thickness part 422 in a wide area, for example, heat can be efficiently transmitted to the mist trap part 350.

  As described above, the vaporizer 300 that can prevent the reaction product from being deposited on the liquid material discharge nozzle 322 and can supply a good material gas containing no unvaporized component at a sufficient flow rate is specifically described. Can be configured.

(Configuration example of vaporizer according to the second embodiment)
Next, the structural example of the vaporizer | carburetor concerning 2nd Embodiment is demonstrated, referring drawings. FIG. 8 is a longitudinal sectional view showing a schematic configuration example of the vaporizer 500 according to the second embodiment. The vaporizer 500 is obtained by replacing the upper housing 400 and the intermediate housing 402 of the vaporizer 300 shown in FIG. 5 with an upper housing 510 and an intermediate housing 512, respectively. Therefore, among the components shown in FIG. 8, those having the same functions as the components shown in FIG.

  A vaporizer 500 shown in FIG. 8 is a specific example in the case where a carrier gas channel 530 is formed in the upper casing 510. 8 includes a buffer chamber 536 formed in the upper housing 510 so as to surround the horn 314 of the ultrasonic transducer 310, and a carrier gas from the carrier gas supply pipe 122 in the buffer chamber 536. Carrier gas introduction flow path 532 and a plurality of carrier gas ejection ports 534 for ejecting the carrier gas from the buffer chamber 536 toward the internal space 502 of the misting chamber 500A.

  Further, in the vaporizer 500 shown in FIG. 8, a cylindrical shielding member 520 is provided so as to surround the discharge port 324 of the liquid material discharge nozzle 322 and the vibration surface 316 of the horn unit 314 from the lower surface of the upper housing 510. It is erected.

  Here, the configuration of the shielding member 520 will be described in more detail with reference to the drawings. FIG. 9 is a view of the CC cross section shown in FIG. 8 as viewed from below. As shown in FIG. 8, the opening diameter of the upper surface of the intermediate housing 512 is larger than the opening diameter of the lower surface of the upper housing 510. A part of the lower surface of the upper housing 510 (a surface around the opening end) is exposed. Thereby, the shielding member 520 can be attached to the exposed lower surface of the upper casing 510. For example, as shown in FIG. 8, the shielding member 520 is attached by fitting a flange portion 522 provided at the upper end of the shielding member 520 into a hole formed in the lower surface of the upper housing 510.

  In this embodiment, as shown in FIGS. 8 and 9, a carrier gas jet port 534 is formed in the flange portion 522 along the outer periphery of the shielding member 520, and is communicated with the buffer chamber 536. Carrier gas can be ejected from the outside of 520.

  The inner space 502 of the misting chamber 500 </ b> A formed in the intermediate housing 512 gradually decreases in diameter from the upper surface of the intermediate housing 512, and a throttle portion 504 is formed. The throttle unit 504 communicates with the inlet 305 of the vaporization chamber 300B, and the mist-like liquid material generated in the internal space 502 of the mist chamber 500A passes from the throttle unit 504 via the inlet 305 to the vaporization chamber 300B. Supplied in. Note that a liquid source supply flow path 320 is formed in the intermediate housing 512 in the same manner as the intermediate housing 402 shown in FIG.

  According to the vaporizer 500 shown in FIG. 8, the cylindrical shielding member 520 is provided so as to surround the discharge port 324 of the liquid source discharge nozzle 322, and the carrier gas outlet 534 is provided outside thereof, thereby shielding A carrier gas flow path can be formed by a space formed between the outer peripheral surface of the member 520 and the inner wall of the mist chamber 500A. Thus, the carrier gas can be ejected from the downstream side of the discharge port 324 of the liquid material discharge nozzle 322 toward the vaporization chamber 300B through the outside of the shielding member 520. For this reason, the discharge port of the liquid raw material inside the shielding member 520 is not exposed to the carrier gas. Therefore, as in the first embodiment, even if the carrier gas contains a small amount of moisture, the moisture and the components of the liquid source do not react with each other, and as a result, the reaction product becomes the liquid source discharge nozzle 322. There is no such thing as depositing inside. Thereby, it is possible to prevent the liquid material discharge port 324 from being blocked.

  In addition, since the carrier gas flow path is formed by the space formed between the outer peripheral surface of the shielding member 520 and the inner wall of the mist formation chamber 500A, the mist-like liquid material generated inside the shielding member 520 is used. It can be efficiently transferred toward the vaporization chamber 300B on the downstream side. That is, since the mist-like liquid material generated inside the shielding member 520 overflows from the opening at the lower end of the shielding member 520, it is efficiently lowered by the carrier gas ejected downward from the periphery of the shielding member 520. Can be transferred to the vaporization chamber 300B.

  Further, since the length of the shielding member 520 shown in FIG. 8 is relatively short and the lower end thereof is positioned upstream of the throttle portion 504 in the mist chamber 500A, the carrier gas is also reduced in the throttle portion 504. From the upstream side to the vaporization chamber 300B. As a result, the mist-like liquid material overflowing from the lower end of the shielding member 520 does not flow back into the internal space 502 upstream of the throttle portion 504 and does not fill the vapor chamber 300 </ b> B quickly with the carrier gas. Can be transported towards.

  The length of the shielding member 520 is not limited to that shown in FIG. For example, like the vaporizer 540 illustrated in FIG. 10, the length of the shielding member 520 may be extended so that the lower end of the shielding member 520 is positioned near the lower end of the throttle portion 504.

  According to this, the flow path of the carrier gas formed between the outer peripheral surface of the shielding member 520 and the inner wall of the misting chamber 500A is formed from the opening end of the upper surface of the intermediate housing 512 to the throttle portion 504. The For this reason, the flow path of the carrier gas gradually becomes narrower from the opening end on the upper surface of the intermediate housing 512 to the throttle portion 504 and becomes the smallest in the vicinity of the throttle portion 504 at the lower end of the shielding member 520.

  For this reason, the carrier gas ejected from the carrier gas ejection port 534 gradually increases in flow rate while flowing outside the shielding member 520 and is ejected from around the lower end of the shielding member 520 at the highest speed. At this time, since the pressure in the vicinity of the lower end of the shielding member 520 is lower than the upper end, the mist-like liquid material generated in the shielding member 520 by the so-called ejector action can be drawn out from the shielding member 520. Therefore, the mist-like liquid source can be more efficiently transferred to the vaporization chamber 300B, and the source gas can be generated efficiently.

  Further, even with the shielding member 520 shown in FIG. 10, since the carrier gas passes outside the shielding member 520, the liquid material discharge port 324 inside the shielding member 520 is not exposed to the carrier gas. Therefore, even if the carrier gas contains a small amount of moisture, the moisture does not react with the components of the liquid material, and the liquid material discharge port 324 can be prevented from being blocked.

  In addition, by making the shielding member 520 longer, the flow path of the carrier gas formed on the outer side of the shielding member 520 becomes longer, and the rectifying effect of the carrier gas can be enhanced. Therefore, the carrier gas ejected from the outside of the shielding member 520 draws the mist-like liquid material from the shielding member 520, and then does not diffuse the mist-like liquid material, so that the surface of the vaporization section 340 in the vaporization chamber 300B Can be transferred. For this reason, the vaporization efficiency of the mist-like liquid raw material in the vaporization part 340 can be improved.

  In the above-described embodiments, the mist chambers 300A, 500A, and 540A have been described in the case where the plurality of carrier gas ejection ports 334 and 534 are formed in the shape of pores, and these are arranged circumferentially. For example, the carrier gas outlet may be formed in an annular slit.

  In addition to the carrier gas outlets 334 and 534, another carrier gas outlet may be provided. For example, another carrier gas ejection port is provided at a position close to the vaporizing unit 340 so that the carrier gas is ejected from there toward the surface of the vaporizing unit 340. In this way, the mist-like liquid material transferred by the carrier gas ejected from each of the carrier gas outlets 334 and 534 can be more reliably guided to the surface of the vaporizing unit 340, and the liquid material can be vaporized. Efficiency can be further improved.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, 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 of course within the technical scope of the present invention. Understood.

  For example, the vaporizer according to the present invention can be applied to a vaporizer used for MOCVD apparatus, plasma CVD apparatus, ALD (atomic layer deposition) apparatus, LP-CVD (batch type, vertical type, horizontal type, mini-batch type), etc. It is.

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

It is a figure which shows the structural example 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. FIG. 6 is a cross-sectional view for explaining the positional relationship between the liquid material discharge port and the vibration surface of the ultrasonic transducer in the embodiment. It is a schematic diagram for demonstrating operation | movement of the ultrasonic transducer | vibrator in the embodiment. It is a longitudinal cross-sectional view which shows the specific structural example of the vaporizer | carburetor shown in FIG. It is AA sectional drawing of the vaporizer | carburetor shown in FIG. It is BB sectional drawing of the vaporizer | carburetor shown in FIG. It is a longitudinal cross-sectional view which shows the schematic structural example of the vaporizer | carburetor concerning 2nd Embodiment. It is CC sectional drawing of the vaporizer | carburetor shown in FIG. It is a longitudinal cross-sectional view which shows the other structural example of the vaporizer | carburetor shown in FIG.

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 116 Liquid raw material 120 Carrier gas supply source 122 Carrier gas supply piping 124 Carrier gas flow control valve 132 Raw material gas supply piping 134 Raw material gas flow control valve 140 Control unit 200 Film forming chamber 210 Side wall member 212 Top wall member 214 Bottom wall member 222 Susceptor 224 Support member 226 Heater 228 Power supply 230 Exhaust port 232 Exhaust means 240 Shower head 242 Internal space 244 Gas discharge hole 300 Vaporizer 300A, 500A, 540A Misting chamber 300B Vaporizing chamber 301 Housing 302 Internal space 303 of the misting chamber 303 Insertion hole 304 Expanded portion 305 Introduction port 306 Internal space of the vaporization chamber 307 Upper bottomed hole 308 Lower bottomed hole 310 Ultrasonic vibrator 312 Piezoelectric Elementary Child 314 Horn portion 316 Vibration surface 318 Flange portion 320 Liquid source supply channel 322 Liquid source discharge nozzle 324 Discharge port 330 Carrier gas supply channel 332 Carrier gas introduction channel 334 Carrier gas outlet 336 Buffer chamber 340 Vaporization unit 341 Vaporization member 342 Through-hole 344 Vaporizing section heater 350 Mist trap section 351 Breathable member 352 Mist trap section heater 360 Outlet 400 Upper casing 402 Middle casing 404 Lower casing 407 Insertion hole 408 Bottom plate 410 Stop plate 414 Upper flange 416 Lower flange 418, 432, 434 Seal member 420, 430 Bolt 422 Thickness portion 424 Through hole 426 Mounting member 500, 540 Vaporizer 500A Mistification chamber 502 Internal space 504 of the mist formation chamber Lower portion 510 Upper casing 512 Middle portion Housing 520 Shield member 522 Flange portion 530 Carrier gas channel 532 Carrier gas introduction channel 534 Carrier gas outlet 536 Buffer chamber W Wafer

Claims (7)

A misting chamber that mists the liquid material;
A vaporization chamber provided in communication with the downstream side of the mist chamber, and vaporizing the mist-like liquid source from the mist chamber to generate a source gas;
The mist chamber is
A liquid source supply flow path communicating with a discharge port for discharging the liquid source provided in the mist chamber;
An ultrasonic vibrator having a vibration surface facing the liquid material discharge port;
A carrier gas supply that communicates with a jet outlet that jets a carrier gas that transports a mist-like liquid source due to vibration of the ultrasonic vibrator from the downstream side of the outlet of the liquid source toward the vaporization chamber. A flow path,
A vaporizer characterized by providing The vaporizer according to claim 1, wherein the carrier gas ejection port is provided downstream of the liquid material ejection port. A cylindrical shielding member that surrounds and shields the periphery of the discharge port of the liquid source is provided, and an outer surface of the shielding member and the outer surface of the shielding member are provided by providing an outlet of the carrier gas outside the shielding member. The carrier gas is allowed to flow between the inner wall of the mist chamber and the carrier gas is ejected from the periphery of the shielding member from which the mist-like liquid material is discharged toward the vaporization chamber. The vaporizer according to claim 1, wherein 4. The inner wall of the mist chamber is gradually throttled toward the lower end of the shielding member, and a throttle part is formed in the vicinity of the end of the shielding member from which the carrier gas is ejected. The vaporizer described in. 5. The ultrasonic transducer is arranged so that a vibration surface thereof faces downward, and the liquid material is discharged upward from an ejection port. 6. Vaporizer. The vaporization chamber is
An inlet for introducing a mist-like liquid material from the mist chamber;
It comprises a plate-like vaporizing member that divides the vaporizing chamber into an upstream space communicating with the introduction port and a downstream space, and the upstream space and the downstream along the circumferential direction of the vaporizing member. A vaporization part formed with a plurality of through holes communicating with the side space;
A vaporizer heater for heating the vaporizing member;
A mist trap portion made of a plate-like breathable member having a breathability provided so as to close a space downstream of the vaporization portion;
A mist trap part heater for heating the mist trap part;
A delivery port that is provided downstream of the mist trap, and that is heated in the vaporization unit and the mist trap unit and is vaporized in the mist trap and passes through these outlets,
The vaporizer according to claim 1, comprising: A liquid source supply system for supplying a liquid source, a carrier gas supply system for supplying a carrier gas, a vaporizer for vaporizing the liquid source to generate a source gas, and introducing the source gas from the vaporizer A film forming apparatus having a film forming chamber for performing a film forming process on a processing substrate,
The vaporizer is provided in communication with a mist formation chamber for forming a liquid material in a mist form, and a downstream side of the mist formation chamber, and vaporizes the mist liquid material from the mist formation chamber to form a raw material gas. A vaporizing chamber for generating
The mist chamber includes a liquid material supply channel that is provided in the mist chamber and communicates with a discharge port that discharges the liquid material, and an ultrasonic vibrator having a vibration surface that faces the liquid material discharge port. , A carrier gas that communicates a carrier gas that transports the liquid material that has been made mist by the vibration of the ultrasonic vibrator, from a downstream side of the liquid material discharge port toward the vaporization chamber. And a supply channel.

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