WO2006049198A1

WO2006049198A1 - Carburetor and film-forming device

Info

Publication number: WO2006049198A1
Application number: PCT/JP2005/020189
Authority: WO
Inventors: Teruo Iwata
Original assignee: Tokyo Electron Limited
Priority date: 2004-11-05
Filing date: 2005-11-02
Publication date: 2006-05-11
Also published as: JP2006135053A

Abstract

A carburetor and a film-forming device. In the carburetor (30), a plurality of chevron-like projections (40) are formed in a wall surface forming a vaporizing chamber (32) projectedly toward the vaporizing chamber (32) and act so as to cut off the flow of a mist sprayed from a vaporizing nozzle (35) near the wall surface among the flows of the mist. Accordingly, an area in the shade of the flow of the mist sprayed from the vaporizing nozzle (35) is formed on the wall surface of the vaporizing chamber (32). Since deposits are not almost adhered to the shaded area, a heat exchange efficiency can be prevented from being excessively lowered to stably maintain mist vaporizing performance.

Description

Vaporizer and deposition system

Technical field

TECHNICAL FIELD [0001] 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.

Background art

[0002] In a film forming apparatus that forms a film on an object to be processed by a method such as a CVD (Chemical Vapor Deposition) method, a liquid raw material is stably vaporized in large quantities and supplied as a raw material gas to a film forming chamber. A vaporizer is used for the purpose. As such a vaporizer, a mist type vaporizer has been proposed in which a liquid material is vaporized by spraying in a vaporized chamber heated from a nozzle in a mist state (for example, Patent Document 1).

[0003] Fig. 1 shows the general configuration of a mist type vaporizer. The vaporizer 200 has a vaporization chamber 202 formed in a main body 201 provided with a heating means. The mist 210 of the raw material sprayed from the nozzle 203. The thermal atmosphere in the vaporization chamber 202 and the vaporization chamber 202. It is heated by contact with the wall surface to become a raw material gas, and is supplied to a film forming chamber (not shown).

Patent Document 1: Japanese Patent Laid-Open No. 11-342328

Disclosure of the invention

[0004] However, in the conventional air vessel 200, during repeated use, a solidified product produced by volatilization of only the solvent from the raw material mist 210, a thermal decomposition product of the raw material produced by heating, or a raw material There is a problem that solid matter such as impurities contained therein 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 system, a uniform thin film must be formed, so it is necessary to supply the source gas stably to the film formation chamber. If the vaporization efficiency of the vaporizer 200 decreases, a part of the mist 210 is not vaporized. It mixes with the source gas and flows into the film formation chamber, causing problems such as depositing of parts on the object to be processed and film defects such as poor film quality.

[0005] The present invention has been made in view of the above circumstances, and even if the use of a vaporizer is repeated, It is an object of the present invention to provide a vaporizer capable of stably supplying a raw material gas without drastically reducing the vaporization efficiency of the raw material in the vaporizing chamber and a film forming apparatus equipped with the vaporizer.

[0006] In order to solve the above problems, according to a first aspect of the present invention,

A vaporization chamber formed in a hollow container provided with heating means;

A nozzle for spraying a liquid material into the vaporization chamber;

A deriving unit for deriving vaporized gas from the vaporization chamber;

A plurality of convex portions provided on the wall surface of the vaporizing chamber;

A vaporizer with is provided.

[0007] In the first aspect, it is preferable that the convex portion is provided so as to form a region that becomes a trap for the flow of mist sprayed from the nozzle.

Further, it is preferable that the convex portion is provided so as to block a flow in the vicinity of the wall surface of the vaporization chamber among the flow of mist sprayed from the nozzle.

Further, the convex portion may be provided so as to form a deposition region where a solid matter derived from mist sprayed from the nozzle is deposited and a non-deposition region where the solid matter is not deposited. preferable.

[0008] 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.

[0009] In addition, the vaporization chamber is preferably formed in a cylindrical shape longer than the distance between the wall surfaces in the direction orthogonal to the distance force to the wall surface facing the 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.

[0010] The vaporizer according to the first aspect described above is preferably connected to a film forming chamber in which a film is formed by a CVD method and supplies a source gas to the film forming chamber.

[0011] Further, according to the second aspect of the present invention, a vaporization chamber formed in a hollow container provided with a heating means, a nozzle for spraying a liquid raw material into the vaporization chamber, and the vaporization chamber The A vaporizer comprising a deriving section for deriving the generated gas, and a plurality of convex portions provided on the wall surface of the vaporizing chamber;

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.

[0012] 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, which is caused by the mist carried over to the vaporizer chamber. Generation of particles and defective film formation can be reliably prevented. This makes it possible to improve the productivity of film formation.

Brief Description of Drawings

[0013] FIG. 1 is a drawing showing an outline of a prior art vaporizer.

FIG. 2 is a drawing showing an example of the configuration of a film forming apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a schematic configuration of a vaporizer according to the first embodiment of the present invention.

FIG. 4A is a schematic diagram showing a state of a wall surface of a prior art vaporizer.

FIG. 4B is a schematic diagram showing a state in which a deposit layer is formed on the wall surface of a prior art vaporizer.

FIG. 5A is a schematic diagram showing the state of the wall surface of the vaporizer according to the first embodiment.

FIG. 5B is a schematic diagram showing a state in which a deposit layer is formed on the wall surface of the vaporizer according to the first embodiment.

FIG. 6 is a cross-sectional view showing a schematic configuration of a vaporizer according to a second embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a drawing showing a schematic configuration example of a film forming apparatus 100 provided with a vaporizer of the present invention. This film forming apparatus 100 is, for example, for forming an Hf (hafnium) oxide film on a semiconductor wafer W (hereinafter simply referred to as “wafer W”) by CVD, and forming a chamber constituting a processing unit. 10, a liquid raw material supply source 20 for supplying a liquid raw material containing Hf, a vaporizer 30 for vaporizing the liquid raw material supplied from the liquid raw material supply source 20 to generate a raw material gas, and the generated raw material gas And a raw material gas pipe 50 to be supplied to the chamber 10.

The chamber 10 has a substantially cylindrical shape and is configured to be evacuated. A susceptor 11 for horizontally supporting a wafer W as a processing object is included in the plurality of cylindrical support portions. It is arranged in a state supported by a material 12 (only one is shown here). 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 having a vacuum pump or the like (not shown) 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 19a, and the raw material gas formed by vaporization in the vaporizer 30 is introduced into the shower head 19. The shower head 19 has an internal space 19b, and a large number of gas discharge holes 19c 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 from the gas discharge hole 19c toward the semiconductor wafer W on the susceptor 11.

In the film forming apparatus 100 of the present embodiment, the liquid raw material supply source 20 stores a hafnium-based organometallic compound, and sends the liquid raw material toward the vaporizer 30 through the raw material pipe 20a. Here, as the hafnium-based organometallic compound, for example, tetratertiary butoxy 'no-fumium [Hf (Ot-Bu)], tetrajetylamino' hafnium [Hf (NEt)

4 2 4

], Tetrakis methoxymethyl propoxy [Nofnium [Hf (MMP)], Tetradimethylamino

Four

NONOFU-UM [Hf (NMe)], tetramethylethylamino'hafnium [Hf (NMeEt)]

2 4 4

, Hafnium-based organic gold such as tetrakistriethylsiloxy 'nofnium [Hf (OSiEt)]

3 4

Mention may be made of the genus compounds.

[0019] 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)], tetraethoxy 'silicon [Si (OEt)], tetradimethylamino' silicon [Si (

4 4

NMe)], tetrakismethoxymethylpropoxyzirconium [Zr (MMP)],

2 4 4

Cylcyclopentadienyl ruthenium [Ru (EtCp)], tertiary amylimide tri

2

Dimethylamide 'tantalum [Ta (Nt— Am) (NMe)], trisdimethylaminosilane [HSi (

twenty three

NMe)] can also be used. [0020] 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. 2, when the liquid raw material is not completely vaporized, a part of the liquid raw material is mixed with the raw material gas as fine mist and sent to the raw material gas pipe 50 to reach the chamber 10. There is a case. The mist mixed in the chamber 10 becomes a cause of generation of particles and a factor of deteriorating the film quality of the hafnium oxide film. Therefore, in the present embodiment, the vaporizer 30 having the configuration shown in FIG. 3 is used.

FIG. 3 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 such 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.

[0023] A vaporizing nozzle 35 is disposed at one end of the vaporizing chamber 32. The 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, and is sprayed. It constitutes a stage. A carrier gas ejection portion 38a is provided around the nozzle block 35b forming the vaporizing nozzle 35. The carrier gas ejection portion 38a 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, N, He, A

An inert gas such as 2 r is preferably used.

The vaporization chamber 32 is a distance from the vaporization nozzle 35 to the wall surface 31a facing the vaporization nozzle 35.

It is formed in a substantially cylindrical shape whose length (that is, the length in the mist injection direction) is longer than the distance between the wall surfaces in the direction orthogonal thereto. 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 the heat supplied from the gas force in the vaporizing chamber 32 during the flight. The distance from the vaporizing nozzle 35 to the wall surface 31a facing the vaporizing nozzle 35 can be appropriately set according to the temperature distribution in the vaporizing 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 direction perpendicular to the direction.

[0025] The wall surface forming the vaporization chamber 32 is provided with a plurality of chevron projections 40 as convex portions. . Each chevron 40 is projected in a cross-sectional view so that its top is directed toward the vaporizing chamber 32. That is, each chevron 40 is projected inward so as to make one round of the inner circumferential surface of the substantially cylindrical vaporizing chamber 32. The chevron 40 is continuously provided in a direction orthogonal to the flow direction of the mist so as to block the flow in the vicinity of the wall surface of the flow of mist 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 drought area, the drastic reduction in the amount of heat supplied by the wall force of the vaporization chamber 32 is prevented, and the vaporization performance of the mist can be stably maintained. The action of the chevron 40 will be described later.

[0026] On the side surface of the main body 31, a raw material gas outlet passage 39 is provided as a gas outlet portion for communicating 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 this 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 discharge passage 39. Therefore, it is possible to reduce the possibility that the mist is directly discharged from the raw material gas outlet passage 39.

Then, the liquid raw material is sprayed into the vaporizing chamber 32 from the vaporizing nozzle 35 and a carrier gas such as nitrogen gas is introduced from the carrier gas ejection part 38a. While being diffused, the gas is quickly vaporized, mixed with the carrier gas, and supplied as a source gas from the source gas outlet passage 39 to the source gas pipe 50. The vaporization of the mist in the vaporization chamber 32 occurs 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 heated by this gas, and the mist is heated and vaporized indirectly through this gas.

[0028] Here, the action of the chevron 40 will be described in more detail with reference to the force S with reference to FIGS. 4A, 4B, 5A, and 5B. In FIGS. 4A, 4B, 5A, and 5B, the amount of heat supplied by the wall surface of the vaporizing chamber is indicated by white arrows.

First, problems in the conventional vaporizer 200 (see FIG. 1) will be described. 4A and 4B schematically show the cross-sectional structure of the main part of the wall of the vaporizing chamber 202 in the conventional air heater 200. The 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).

[0029] In the initial stage of use of the air conditioner 200, as shown in FIG. 4A, 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 vaporizing chamber 202. . However, during repeated use of the vaporizer 200, 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, vaporization of the mist supplied from the nozzle 203 force becomes insufficient, and the mist is carried over to the film formation chamber without being vaporized, causing particles and film formation defects.

[0030] In the case of the carburetor 30 (Fig. 3) according to the present embodiment, the chevron projection 40 blocks the flow in the vicinity of the wall surface of the vaporization chamber 32 out of the mist flow sprayed from the vaporization nozzle 35. Is provided. As a result, on the wall surface of the vaporizing chamber 32, a region that becomes a trap for the flow of mist sprayed from the vaporizing nozzle 35 is formed. Specifically, the mist flow is blocked by the region 40a in FIG. 5A, and the region 40b becomes trapped with respect to the mist flow.

[0031] As the vaporizer 30 continues to be used, as shown in FIG. 5B, the solid matter adheres to the region 40a to form the deposit layer 300, but the solid matter adheres to the region 40b. Almost no occurrence occurs and the attachment layer 300 is not formed. That is, the region 40a is a deposition region where solid matter derived from mist is deposited, and the region 40b is a non-deposition region where no solid matter is deposited. Therefore, in this area 40b, the amount of heat supplied 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 vaporization chamber 32 can be maintained and secured.

[0032] 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 the mist is stable. Maintained. The chevron 40 as the convex portion is preferably provided on a portion where solid matter is likely to adhere, for example, at least on the wall surface 3 la facing the vaporizing nozzle 35 and in the vicinity thereof, and provided on the entire wall surface of the vaporizing chamber 32. More preferred.

Note that the number of chevron protrusions 40, the height of the protrusions, the ratio of the region 40b that becomes the ridge, etc. Determined by taking into account the type of organometallic compound in the raw material (ease of solids), the size and shape of the vaporization chamber 32, the strength of the mist sprayed from the vaporization nozzle 35, the amount of carrier gas jetted, etc. can do.

[0033] As described above, in the film forming apparatus 100 incorporating the vaporizer 30, since a constant supply heat amount is always maintained for the gas in the vaporization chamber 32 even when used for a long time, the mist is vaporized. Therefore, it is possible to prevent the transition to the chamber 10. Therefore, generation of particles due to mist and film formation defects can be prevented, and a high-quality thin film can be stably formed.

FIG. 6 is a drawing showing a schematic configuration of the vaporizer 130 according to the second embodiment of the present invention.

In the vaporizer 130 of the second embodiment, the same components as those of the vaporizer 30 of the first embodiment shown in FIG.

The vaporizer 130 is provided with a plurality of wall bodies 41 projecting in a plate shape with respect to the wall surface of the vaporization chamber 32. The wall body 41 is formed in a ring shape along the inner peripheral surface of the substantially cylindrical vaporizing chamber 32. The wall body 41 is continuously provided in a direction orthogonal to the flow direction of the mist so as to block the flow in the vicinity of the wall surface of the flow of mist sprayed from the vaporizing nozzle 35. 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. The wall body 41 is preferably made of the same material having the same thermal conductivity as the main body 31, such as SUS.

[0036] The action of the wall body 41 is basically the same as that of the chevron 40 in FIG. 3, 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. To do. Solid matter adheres to the upper surface of the wall 41 (the surface facing the mist flow direction), but the lower surface of the wall 41 and the wall surface exposed between the wall 41 and the wall 41 (exposed surface of the main body 31) In this case, it is difficult for the deposit layer 300 made of solid matter to form the wall 41. Therefore, in the region without the deposit layer 300, sufficient heat is supplied to the gas in the vaporizing chamber 32 without decreasing the amount of supplied heat, and the mist is vaporized stably.

Note that the number of wall bodies 41, the height of the protrusions, the ratio of the wrinkled region, etc. are, for example, the type of organometallic compound in the liquid raw material (ease of generating solids), and the size and shape of the vaporization chamber 32 This can be determined in consideration of the strength of the mist sprayed from the vaporizing nozzle 35 and the amount of carrier gas jetted. [0037] The embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. That is, the above embodiment is intended to clarify the technical contents of the present invention, and the present invention is not limited to such specific examples. Various modifications can be made within the scope described in the spirit and claims.

For example, in the first embodiment (FIG. 3) and the second embodiment (FIG. 6), the configuration in which the protrusions 40 and the plate-like wall body 41 are provided as the protrusions is described. It is not limited to that as long as it can form a region that becomes a trap for the flow of mist.

Further, for example, in the first embodiment, the chevron 40 is formed toward the vaporization chamber 32 in order to form the convex portion. However, a groove is formed in the main body 31 constituting the wall of the vaporization chamber 32. This also makes it possible to form substantially the same convex portion.

Industrial applicability

The present invention can be suitably used when a film forming process represented by, for example, the CVD method is performed in the manufacturing process of various semiconductor devices.

Claims

The scope of the claims

[I] a vaporization chamber formed in a hollow container provided with heating means;

A nozzle for spraying a liquid material into the vaporization chamber;

A deriving unit for deriving vaporized gas from the vaporization chamber;

Vaporizer with

[2] The vaporizer according to [1], wherein the convex portion is provided so as to form a region that becomes trapped with respect to a flow of mist sprayed from the nozzle.

[3] 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 vaporizing chamber in a flow of mist sprayed from the nozzle.

[4] 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.

The vaporizer according to 1.

[5] The vaporization according to claim 1, wherein the convex portion protrudes in a mountain shape toward the vaporization chamber.

[6] The vaporization according to claim 1, wherein the convex portion protrudes in a plate shape toward the vaporization chamber.

7. The vaporizer according to claim 1, wherein the convex portion is provided at least on a wall surface facing the nozzle and in the vicinity thereof.

[8] The vaporization according to claim 1, wherein the convex portion is provided on substantially the entire wall of the vaporization chamber.

[9] The vaporization chamber according to claim 1, wherein the vaporizing chamber is formed in a cylindrical shape that is longer than a distance between wall surfaces in a direction perpendicular to the nozzle force. Vaporizer.

10. 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.

[II] The vaporizer according to claim 1, wherein the vaporizer is connected to a film forming chamber in which a film is formed by a CVD method and supplies a source gas to the film forming chamber. A vaporization chamber formed in a hollow container provided with a heating means, a nozzle for spraying a liquid raw material into the vaporization chamber, a lead-out portion for deriving vaporized gas from the vaporization chamber, and a wall surface of the vaporization chamber A plurality of protrusions provided on the carburetor,

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.