JP2006135053A - Evaporizer and depositing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaporizer which can stably supply a material gas without extremely lowering evaporization efficiency of a material in an evaporization chamber even if the evaporizer is repeatedly used, and to provide a depositing device equipped with the evaporizer. <P>SOLUTION: An evaporizer 30 is provided with an evaporization chamber 32. A plurality of hemispherical projections 40 are provided on the wall surface forming an evaporization chamber 32, and the projections 40 are directed toward the evaporization chamber 32 to block the flow of mist adjacent to the wall surface among the flows of mist sprayed from an evaporization nozzle 35. Thus, an area into which no flow of mist from the evaporization nozzle 35 enters is formed on the wall surface of the evaporization chamber 32. Since almost no object is adhered to the area, the sharp drop of heat exchange efficiency can be prevented, thereby keeping evaporization performance of mist stably. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vaporizer and a film forming apparatus, and more particularly to a vaporizer and a film forming apparatus used in a film forming process in which a liquid raw material is vaporized and deposited on the surface of an object to be processed.

  In a film forming apparatus that forms a film on a target object by a method such as CVD (Chemical Vapor Deposition), a vaporizer is used for the purpose of vaporizing a liquid raw material stably and in large quantities and supplying it as a raw material gas to a film forming chamber Is used. As such a vaporizer, a mist type vaporizer has been proposed in which a liquid material is vaporized by being sprayed in a vaporized chamber heated from a nozzle in a mist state (for example, Patent Document 1).

A general configuration of a mist type vaporizer is shown in FIG. The vaporizer 200 has a vaporization chamber 202 formed in a main body 201 provided with a heating means, and the mist 210 of the raw material sprayed from the nozzle 203 is heated in the vaporization chamber 202 and in the vaporization chamber 202. The material gas is heated by contact with the wall surface and is supplied to a film forming chamber (not shown).
JP-A-11-342328

  However, in the conventional vaporizer 200, during repeated use, the solidified product generated by volatilization of only the solvent from the raw material mist 210, the thermal decomposition product of the raw material generated by heating, and impurities contained in the raw material There is a problem that the solid matter such as the above adheres to the wall surface of the vaporization chamber 202 and the vaporization efficiency decreases. In particular, when the liquid raw material to be vaporized contains a hafnium-based organometallic compound, deposits tend to be easily formed on the wall surface of the vaporization chamber 202. In the CVD apparatus, it is necessary to stably supply a raw material gas to the film forming chamber in order to form a uniform thin film. However, if the vaporization efficiency in the vaporizer 200 is reduced, the raw material gas is partially evaporated without being vaporized. The gas is mixed into the gas and flows into the film formation chamber, which causes film formation troubles such as adhesion of particles to the object to be processed and poor film quality.

  The present invention has been made in view of the above circumstances, and even if the use of the vaporizer is repeated, the raw material gas can be stably supplied without extremely reducing the vaporization efficiency of the raw material in the vaporization chamber. An object is to provide a vaporizer and a film forming apparatus including the vaporizer.

In order to solve the above problem, according to a first aspect of the present invention, a vaporization chamber formed in a hollow container provided with a heating means,
Spraying means comprising a nozzle for spraying the liquid raw material into the vaporizing chamber;
A deriving unit for deriving vaporized gas from the vaporization chamber;
A vaporizer with
A vaporizer is provided, wherein a plurality of convex portions are provided on a wall surface of the vaporization chamber.

In the first aspect, it is preferable that the convex portion is provided so as to form a region that becomes a wrinkle with respect to a flow of mist sprayed from the nozzle.
Moreover, it is preferable that the said convex part is provided so that the flow of the wall surface vicinity of the said vaporization chamber may be interrupted | blocked among the flows of mist sprayed from the said nozzle.
Moreover, it is preferable that the said convex part is provided so that the deposition area | region where the solid substance derived from the mist sprayed from the said nozzle may accumulate and the non-deposition area | region where this solid substance may not be deposited may be formed.

It is preferable that the convex portion protrudes in a mountain shape toward the vaporization chamber or protrudes in a plate shape toward the vaporization chamber.
Further, it is preferable that the convex portion is provided at least on the wall surface facing the nozzle and in the vicinity thereof, and provided on substantially the entire wall of the vaporizing chamber.

  Moreover, it is preferable that the said vaporization chamber is formed in the cylindrical shape longer than the distance between the wall surfaces of the direction orthogonal to this from the nozzle to the wall surface which opposes this nozzle. Here, it is preferable that the lead-out portion is provided at a position close to the nozzle between the nozzle and a wall surface facing the nozzle.

  The vaporizer according to the first aspect described above is preferably connected to a film formation chamber in which a film is formed by a CVD method and supplies a source gas to the film formation chamber.

According to a second aspect of the present invention, the vaporizer according to the first aspect,
There is provided a film forming apparatus comprising: a film forming chamber for forming a film on an object to be processed using a source gas supplied from the vaporizer.

  According to the present invention, by providing a plurality of convex portions on the wall surface of the vaporization chamber, it is possible to stabilize the vaporization efficiency in the vaporizer, generation of particles due to mist carried over from the vaporizer to the film formation chamber, Film formation defects can be reliably prevented. As a result, the productivity of film formation can be improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration example of a film forming apparatus 100 provided with a vaporizer according to the present invention. The film forming apparatus 100 forms, for example, an Hf (hafnium) oxide film by CVD on a semiconductor wafer W (hereinafter simply referred to as “wafer W”), and includes a chamber 10 constituting a processing unit, A liquid source supply source 20 for supplying a liquid source containing Hf, a vaporizer 30 for generating a source gas by vaporizing the liquid source supplied from the liquid source supply source 20, and supplying the generated source gas to the chamber 10 The raw material gas piping 50 is provided.

  The chamber 10 has a substantially cylindrical shape and is configured to be evacuated, and a susceptor 11 for horizontally supporting a wafer W as an object to be processed is included in a plurality of cylindrical support members 12 (here, (Only one is shown in the figure). In addition, a heater 14 is embedded in the susceptor 11, and the heater 14 is heated by a power source 15 to heat the wafer W as an object to be processed to a predetermined temperature.

  An exhaust port 17 is formed in the bottom wall 10 b of the chamber 10, and an exhaust system 18 is connected to the exhaust port 17. The exhaust system 18 can reduce the pressure in the chamber 10 to a predetermined degree of vacuum.

  A shower head 19 is attached to the top wall 10 a of the chamber 10. A raw material gas pipe 50 is connected to the shower head 19 via a supply control valve 19 a, and a raw material gas formed by being vaporized by the vaporizer 30 is introduced into the shower head 19. The shower head 19 has an internal space 19 b and a large number of gas discharge holes 19 c on the surface facing the susceptor 11. Therefore, the source gas introduced into the internal space 19b of the shower head 19 through the source gas pipe 50 is discharged toward the semiconductor wafer W on the susceptor 11 from the gas discharge hole 19c.

In the film forming apparatus 100 of this embodiment, the liquid source supply source 20 stores a hafnium-based organometallic compound, and sends the liquid source toward the vaporizer 30 through the source pipe 20a. Here, examples of the hafnium-based organometallic compounds include tetratertiary butoxy hafnium [Hf (Ot-Bu) ₄ ], tetradiethylamino hafnium [Hf (NEt ₂ ) ₄ ], tetrakismethoxymethylpropoxy hafnium [Hf]. Hafnium such as (MMP) ₄ ], tetradimethylamino hafnium [Hf (NMe ₂ ) ₄ ], tetramethylethylamino hafnium [Hf (NMeEt) ₄ ], tetrakistriethylsiloxy hafnium [Hf (OSiEt ₃ ) ₄ ] And organic organometallic compounds.

The film formation target is not limited to the hafnium oxide film, and examples of the organic metal compound include pentaethoxy tantalum [Ta (O—Et)], tetratertiary butoxy zirconium [Zr (Ot—Bu) ₄ ], Tetraethoxy silicon [Si (OEt) ₄ ], tetradimethylamino silicon [Si (NMe ₂ ) ₄ ], tetrakismethoxymethylpropoxy zirconium [Zr (MMP) ₄ ], disethyl ethyl cyclopentadienyl ruthenium [Ru] (EtCp) ₂ ], tertiary amylimide tridimethylamide tantalum [Ta (Nt-Am) (NMe ₂ ) ₃ ], trisdimethylaminosilane [HSi (NMe ₂ ) ₃ ] and the like can also be used.

  The organometallic compound is liquid or solid at room temperature, and can be used after being diluted or dissolved in an organic solvent such as octane.

  In the film forming apparatus 100 configured as shown in FIG. 1, when the liquid raw material is not completely vaporized, a part of the liquid raw material may be mixed with the raw material gas as fine mist and sent to the raw material gas pipe 50 to reach the chamber 10. . The mist mixed in the chamber 10 becomes a factor for generating particles and a factor for deteriorating the quality of the hafnium oxide film. For this reason, in this embodiment, the thing of the structure shown in FIG.

  FIG. 2 is a cross-sectional view showing a schematic configuration example of the vaporizer 30 according to the first embodiment of the present invention. The vaporizer 30 includes a main body 31 in which a vaporization chamber 32 is provided, and a heater 33 and a heater 34 disposed so as to surround the vaporization chamber 32. The main body 31 is configured so that the vaporizing chamber 32 can be formed by combining a plurality of blocks (not shown). The main body 31 can be made of a material having high thermal conductivity such as SUS.

A vaporizing nozzle 35 is disposed at one end of the vaporizing chamber 32, and this vaporizing nozzle 35 is connected to the liquid raw material supply source 20 via a raw material flow rate control valve 35a and a raw material pipe 20a to constitute a spraying means. Yes. A carrier gas ejection portion 38 a is provided around the nozzle block 35 b forming the vaporizing nozzle 35, and the carrier gas ejection portion 38 a is provided with a carrier gas via a carrier gas pipe 36 and a carrier gas control valve 37. A carrier gas passage 38 connected to a gas source (not shown) communicates. Here, as the carrier gas, for example, an inert gas such as N ₂ , He, or Ar is preferably used.

  The vaporizing chamber 32 is such that the distance from the vaporizing nozzle 35 to the wall surface 31a facing the vaporizing nozzle 35 (that is, the length in the mist injection direction) is longer than the distance between the wall surfaces in the direction perpendicular thereto. It is formed in a substantially cylindrical shape. This makes it possible to increase the flight distance of the mist sprayed from the vaporizing nozzle 35, and the mist is efficiently vaporized by receiving heat supply from the gas in the vaporizing chamber 32 during the flight. The distance from the vaporization nozzle 35 to the wall surface 31a facing the vaporization nozzle 35 can be appropriately set according to the temperature distribution of the vaporization chamber 32, the amount of mist injection, the amount of carrier gas, etc. It is preferable to set the ratio to about 3 to 5 times the distance between the wall surfaces in the orthogonal direction.

  On the wall surface forming the vaporizing chamber 32, a plurality of chevron projections 40 are provided as convex portions. Each chevron 40 is projected in a mountain shape in cross section so that the top thereof faces the vaporizing chamber 32. The chevron 40 is provided to block the flow in the vicinity of the wall surface of the mist flow sprayed from the vaporizing nozzle 35. As a result, a region that becomes trapped with respect to the flow of mist sprayed from the vaporizing nozzle 35 is formed on the wall surface of the vaporizing chamber 32. Since almost no solid matter adheres to this wrinkled region, an extreme decrease in the amount of heat supplied from the wall of the vaporizing chamber 32 is prevented, and the vaporization performance of mist can be stably maintained. The operation of the chevron 40 will be described later.

  On the side surface of the main body 31, a raw material gas outlet passage 39 is provided as a gas outlet portion that communicates the vaporization chamber 32 with the raw material gas pipe 50. The raw material gas lead-out path 39 is disposed on the side close to the vaporizing nozzle 35 between the vaporizing nozzle 35 and the wall surface 31 a facing the vaporizing nozzle 35. With such an arrangement, the liquid raw material sprayed as mist from the vaporizing nozzle 35 toward the opposing wall surface 31a circulates in the vaporizing chamber 32 after being vaporized and is discharged from the raw material gas outlet passage 39. The possibility that the mist is directly discharged from the source gas outlet path 39 can be reduced.

  Then, the liquid raw material is sprayed from the vaporizing nozzle 35 into the vaporizing chamber 32 and a carrier gas such as nitrogen gas is introduced from the carrier gas ejection portion 38a, so that the liquid raw material is quickly diffused while being diffused into the vaporizing chamber 32. The gas is vaporized and mixed with the carrier gas to be a raw material gas, which is sent from the raw material gas outlet passage 39 to the raw material gas pipe 50. The vaporization of the mist in the vaporization chamber 32 is performed when the mist directly contacts the wall surface of the main body 31 forming the vaporization chamber 32 and is heated to vaporize, or when the gas filled in the vaporization chamber 32 exchanges heat with the wall surface. The mist is indirectly heated through this gas and vaporized by two mechanisms.

Here, the operation of the chevron 40 will be described in more detail with reference to FIGS. 3 and 4. In FIGS. 3 and 4, the amount of heat supplied from the wall surface of the vaporization chamber is indicated by white arrows.
First, problems in the conventional vaporizer 200 (see FIG. 6) will be described. 3A and 3B schematically show a cross-sectional structure of the main part of the wall surface of the vaporizing chamber 202 in the conventional vaporizer 200. FIG. In the main body 201 of the vaporization chamber 200, the wall surface forming the cylindrical vaporization chamber 202 is formed as a concave curved surface in the transverse direction, and is substantially flat in the mist flow direction (longitudinal direction).

  In the initial stage of use of the vaporizer 200, as shown in FIG. 3A, the wall surface is exposed to a material such as metal, so that a sufficient amount of heat is supplied to the gas in the vaporization chamber 202. However, while the vaporizer 200 is repeatedly used, the solid matter gradually adheres to the wall surface as shown in FIG. When the deposit layer 300 is formed, the heat exchange efficiency between the heated wall surface and the gas in the vaporization chamber 202 gradually decreases. For this reason, the vaporization of the mist supplied from the nozzle 203 becomes insufficient, and the mist is carried over to the film formation chamber without being vaporized, causing particles and film formation defects.

  In the case of the vaporizer 30 according to the present embodiment, the chevron 40 is provided so as to block the flow in the vicinity of the wall surface of the vaporization chamber 32 among the flow of mist sprayed from the vaporization nozzle 35. As a result, on the wall surface of the vaporizing chamber 32, a region that becomes trapped with respect to the flow of mist sprayed from the vaporizing nozzle 35 is formed. Specifically, the mist flow is blocked by the region 40a in FIG. 4A, and the region 40b becomes trapped with respect to the mist flow.

  When the use of the vaporizer 30 is continued, as shown in FIG. 4B, solid matter adheres to the region 40a to form the deposit layer 300, but solid matter adheres to the region 40b. Almost no occurrence occurs and the deposit layer 300 is not formed. That is, the region 40a is a deposition region where a solid material derived from mist is deposited, and the region 40b is a non-deposition region where no solid material is deposited. Accordingly, in this region 40b, the heat supply amount from the wall surface indicated by the white arrow does not decrease. As a result, the supply of heat corresponding to the area ratio of the region 40b to the entire wall surface area in the vaporizing chamber 32 is maintained and secured.

By providing the chevron 40 in this way, an extreme decrease in the efficiency of heat exchange between the wall (main body 31) of the vaporizing chamber 32 and the gas in the vaporizing chamber 32 is avoided, and the vaporization performance of mist is stably maintained. The It is preferable that the chevron 40 as the convex portion is provided on a portion where solid matter is likely to adhere, for example, at least in the wall surface 31a facing the vaporizing nozzle 35 and in the vicinity thereof, and more preferably on the entire wall surface of the vaporizing chamber 32. preferable.
Note that the number of chevron projections 40, the height of the projections, the ratio of the region 40b that becomes a ridge, and the like are, for example, the type of organometallic compound in the liquid raw material (ease of generating solid matter), the size of the vaporization chamber 32, and the like. It can be determined in consideration of the shape, the strength of the mist sprayed from the vaporizing nozzle 35, the ejection amount of the carrier gas, and the like.

  As described above, in the film forming apparatus 100 in which the vaporizer 30 is incorporated, a constant supply heat amount is always maintained for the gas in the vaporization chamber 32 even when used for a long period of time. 10 can be prevented. Therefore, it is possible to prevent generation of particles due to mist and film formation failure, and stably form a high-quality thin film.

  FIG. 5 is a diagram showing a schematic configuration of a vaporizer 130 according to the second embodiment of the present invention. In addition, in the vaporizer | carburetor 130 of 2nd Embodiment, the same code | symbol is attached | subjected to the structure same as the vaporizer | carburetor 30 of 1st Embodiment shown in FIG. 2, and description is abbreviate | omitted.

  The vaporizer 130 is provided with a plurality of wall bodies 41 protruding in a plate shape. The wall body 41 is formed in a ring shape. The wall body 41 may be formed by bonding a member made of a material different from that of the main body 31, but may be formed integrally with the main body 31. It is preferable that the main body 1 is made of the same material having excellent thermal conductivity, for example, SUS.

  The action of the wall body 41 is basically the same as that of the chevron 40 of FIG. 2, and a region that becomes a trap for the flow of mist sprayed from the vaporizing nozzle 35 is formed on the wall surface of the vaporizing chamber 32. Solid matter adheres to the upper surface of the wall body 41 (the surface facing the mist flow direction), but the lower surface of the wall body 41 and the wall surface exposed between the wall body 41 and the wall body 41 (exposed surface of the main body 31). Therefore, it becomes difficult for the deposit layer 300 made of solid matter to be formed as a trap of the wall body 41. Therefore, in the region where there is no deposit layer 300, the amount of heat supplied does not decrease, and sufficient heat is supplied to the gas in the vaporizing chamber 32 so that the mist is vaporized stably.

As mentioned above, although embodiment of this invention was described, this invention is not restrict | limited to the said embodiment, A various deformation | transformation is possible.
In the said 1st Embodiment (FIG. 2) and 2nd Embodiment (FIG. 5), although the structure which provided the mountain-shaped protrusion 40 and the plate-shaped wall body 41 as a convex part was mentioned, the form of a convex part is restricted to these. What is necessary is just to be able to form the area | region which becomes a wrinkle with respect to the flow of mist instead of a thing.

  Further, for example, in the first embodiment, the mountain-shaped protrusion 40 is formed toward the vaporizing chamber 32 in order to form the convex portion. However, by forming a groove in the main body 31 constituting the wall of the vaporizing chamber 32, Also, substantially the same convex portion can be formed.

1 is a diagram illustrating a configuration example of a film forming apparatus according to the present invention. Sectional drawing which shows schematic structure of the vaporizer | carburetor which concerns on 1st Embodiment of this invention. The schematic part which shows the state of the wall surface of the vaporizer of a prior art. The schematic diagram which shows the state of the wall surface of the vaporizer | carburetor concerning 1st Embodiment. Sectional drawing which shows schematic structure of the vaporizer | carburetor concerning 2nd Embodiment of this invention. Drawing which shows the outline | summary of the vaporizer | carburetor of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Chamber 10a ... Top wall 10b ... Bottom wall 11 ... Susceptor 12 ... Support member 14 ... Heater 15 ... Power supply 17 ... Exhaust port 18 ... Exhaust system 19 ... Shower head 19a ... Supply control valve 19b ... Internal space 19c ... Gas discharge hole DESCRIPTION OF SYMBOLS 20 ... Liquid raw material supply source 20a ... Raw material piping 30 ... Vaporizer 31 ... Main body 32 ... Vaporization chamber 33 ... Heater 34 ... Heater 35 ... Vaporization nozzle 35a ... Raw material flow control valve 35b ... Nozzle block 36 ... Carrier gas piping 37 ... Carrier gas Control valve 38 ... carrier gas passage 38a ... carrier gas ejection part 39 ... source gas outlet passage 40 ... mountain protrusion 41 ... wall body 50 ... source gas pipe 100 ... film forming apparatus 130 ... vaporizer W ... semiconductor wafer

Claims (12)

A vaporization chamber formed in a hollow container provided with heating means;
Spraying means comprising a nozzle for spraying the liquid raw material into the vaporizing chamber;
A deriving unit for deriving vaporized gas from the vaporization chamber;
A vaporizer with
A vaporizer comprising a plurality of convex portions provided on a wall surface of the vaporization chamber.   The vaporizer according to claim 1, wherein the convex portion is provided so as to form a region that becomes a trap with respect to a flow of mist sprayed from the nozzle.   The vaporizer according to claim 1, wherein the convex portion is provided so as to block a flow in the vicinity of a wall surface of the vaporization chamber in a flow of mist sprayed from the nozzle.   The convex portion is provided so as to form a deposition region in which solid matter derived from mist sprayed from the nozzle is deposited and a non-deposition region in which the solid matter is not deposited. Item 2. A vaporizer according to item 1.   The vaporizer according to any one of claims 2 to 4, wherein the convex portion protrudes in a mountain shape toward the vaporization chamber.   The vaporizer according to any one of claims 2 to 4, wherein the convex portion is provided in a plate shape toward the vaporization chamber.   The vaporizer according to claim 5 or 6, wherein the convex portion is provided at least on a wall surface facing the nozzle and in the vicinity thereof.   The vaporizer according to claim 5 or 6, wherein the convex portion is provided on substantially the entire wall of the vaporization chamber.   The said vaporization chamber is formed in the cylindrical shape longer than the distance between the wall surfaces of the direction orthogonal to this from the said nozzle to the wall surface which opposes this nozzle, The Claim 7 or Claim characterized by the above-mentioned. Item 9. The vaporizer according to Item 8.   The carburetor according to claim 9, wherein the lead-out portion is provided at a position close to the nozzle between the nozzle and a wall surface facing the nozzle.   The vaporizer according to any one of claims 1 to 10, wherein the vaporizer is connected to a film formation chamber in which film formation is performed by a CVD method and supplies a source gas to the film formation chamber. A vaporizer according to any one of claims 1 to 10,
A film forming apparatus comprising: a film forming chamber for forming a film on an object to be processed using a source gas supplied from the vaporizer.

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