Patent Application
20240355645
The present invention relates to a vaporizer capable of efficiently vaporizing a high-viscosity and high-boiling-point liquid material.
In recent semiconductor manufacturing processes, miniaturization and making device structures three-dimensional have been progressing. Along with this, a high-viscosity and high-boiling-point (low-vapor-pressure) liquid material has been used as material for deposition. In such a process, the following problems are involved.
The liquid material has high viscosity and thus does not flow well, and mass flow rate control thereof is extremely difficult. In other words, since the liquid material does not flow at room temperature, the viscosity thereof needs to be reduced. Thus, a material tank, a piping system extending to a vaporizer located downstream of the material tank, and a flow rate controller for liquid installed in the middle of the piping system need to be heated. Furthermore, such a liquid material has a high boiling point. Moreover, if not quickly vaporized, the high boiling point liquid material is thermally denatured, and generates a dimer or a multimer and is solidified, leading to a problem that a passage of the vaporizer is closed. Therefore, the vaporizer to be put in such a process is required to be able to efficiently vaporize an introduced liquid material. That is, to obtain a film thickness with high accuracy in such a semiconductor manufacturing process, a vaporizer that can control the flow rate of a liquid material with high accuracy and then quickly vaporize the same at a high temperature, is required.
A vaporizer described in Patent Literature 1 is proposed as a vaporizer capable of quickly vaporizing a large amount of liquid material. This vaporizer includes: an atomizer for atomizing and spouting a liquid material; a hollow outer tube, made of quartz glass, to which the atomizer is mounted; an inner tube made of quartz glass and housed in the outer tube; and an inner heater block made of metal, provided inside of the inner tube, and including an inner heater therein.
In the vaporizer, a narrow gap between the outer tube and the inner tube serves as a passage, and an atomized liquid material flows in the passage and is vaporized. Since the outer tube and the inner tube are made of quartz glass, the passage, which is a narrow gap therebetween, is formed so as to have the same width (in other words, the passage area described below being of a constant size) from an inlet to an outlet.
The liquid material that is jetted from the atomizer into an atomization space disposed at the top of the outer tube is atomized by carrier gas, and flows into the passage. The atomized liquid material receives heat from the inner tube and the outer tube to be vaporized during flowing in the passage, and the vaporized material (gas) is taken to the outside through the outlet disposed at the end of the passage.
In the vaporizer, an inner packed bed filled with graphite powder is formed between an inner peripheral surface of the inner tube made of glass and an outer peripheral surface of the inner heater block made of metal. The inner heater block made of metal is heated/cooled by turning on/off the inner heater, and the volume thereof expands/contracts. Therefore, the inner packed bed absorbs the expansion/contraction and constantly adheres closely to the inner tube and the inner heater block, thereby efficiently transmitting heat of the inner heater block to the inner tube. Accordingly, heat of the inner heater block is quickly transmitted to the atomized liquid material flowing in the passage, and, even if a large amount of the atomized liquid material flows into the passage, the large amount of the atomized liquid material can be smoothly vaporized.
[PTL 1] Japanese Patent No. 6769645
The vaporizer disclosed in Patent Literature 1 can quickly transmit heat of the inner heater block, via the inner packed bed of graphite powder, to the atomized liquid material flowing in the passage as described above. However, the atomized liquid material is vaporized as advancing in the passage, so that the volume thereof rapidly expands inside the narrow passage.
This passage is narrow, but provides a cylindrical space having a uniform width from the inlet to the outlet and having therein nothing that obstructs the flow. Thus, the atomized liquid material, and even the vaporized material (gas) expanded through vaporization smoothly flow in the passage. The vaporizer is improved such that heat of the inner heater block is quickly transmitted via the inner packed bed to the atomized liquid material flowing in the passage. However, with the configuration described above, the vaporization speed of the atomized liquid material is slow, with respect to the advancing speed of the atomized liquid material. To complete vaporization in the passage, the advancing speed of the atomized liquid material in the passage has to be reduced or the passage has to be made long and large. In the former case, the vaporization amount of the atomized liquid material is limited, and in the latter case, the shape of a device becomes large.
The present invention has been made to solve problems of such a conventional vaporizer. An object of the present invention is to provide a vaporizer that smoothly discharges a rapidly expanded vaporized material to prevent an increase in the internal pressure in the passage and can quickly process a larger amount of liquid material compared to the conventional vaporizer without enlarging the shape of a device.
An invention disclosed in claim 1 is directed to a vaporizer A including: a liquid material introduction port 11; a vaporized material discharge port 21; a vaporizer body 1 in which a passage 7, into which a liquid material L flows, is formed in a vaporization unit 3 extending from the liquid material introduction port 11 to the vaporized material discharge port 21; and a heater 5 that heats the liquid material L flowing in the passage 7.
The passage 7 is formed such that a passage area S represented by a cross-sectional area, of the passage 7, orthogonal to a flowing-through direction of the liquid material L is increased toward the vaporized material discharge port 21 from the liquid material introduction port 11.
In an invention disclosed in claim 2 that is directed to the vaporizer A according to claim 1, the passage 7 branches in the vaporization unit 3, and a divider 8 surrounded by the passage 7 that has branched is formed at a branch portion.
In an invention disclosed in claim 3 (
In an invention disclosed in claim 4 (
In an invention disclosed in claim 5 (
In an invention disclosed in claim 6 that is directed to the vaporizer A according to claim 2, a larger number of the dividers 8 are disposed on the downstream side than on the upstream side.
In an invention disclosed in claim 7 that is directed to the vaporizer A according to any one of claims 1 to 6, ½ of a width W or a depth D of the passage 7 is formed in a range of a temperature boundary layer of the liquid material L.
The passage 7 of the present invention is formed so as to have the passage area S increased toward the vaporized material discharge port 21 from the liquid material introduction port 11, and thus a vaporized material (vaporization gas) G2 having a volume rapidly expanded through vaporization can be quickly discharged from the passage 7. As a result, an increase in the internal pressure in the passage 7 can be suppressed, and vaporization of the liquid material L having flowed through the passage inlet 7a into the passage 7 or inflow of the liquid material L into the passage inlet 7a is not obstructed, so that a large amount of liquid material L can be processed compared to a conventional vaporizer having the same volume. As an additional effect, the vaporizer A can be downsized.
As an example in which the passage area S is increased, the passage 7 is formed so as to branch in the vaporization unit 3. When the passage 7 is formed so as to branch as described above, the vaporized material G2 having a volume rapidly expanded through vaporization in the passage 7 smoothly flows in the passage 7, which branches and the number of which is increased toward the vaporized material discharge port 21, and is discharged, so that an increase in the internal pressure in the passage 7 can be suppressed.
A divider 8 for dividing the passage 7 on the upstream side is formed at a branch portion and is surrounded by the passage 7, and thus heat from the heater 5 can be efficiently supplied through the divider 8 to a fluid (liquid material L or vaporized material G2) flowing in the passage 7.
Here, when each divider 8 is formed in a polygonal shape and one of the corners of the polygon is disposed at the flow dividing point 7k of the passage 7, the fluid (liquid material L or vaporized material G2) can be smoothly branched.
When the polygonal dividers 8 each have a regular hexagonal shape and are arranged in a tortoiseshell manner, the direction of each passage 7 continually changes toward the vaporized material discharge port 21 from the liquid material introduction port 11 in the entire vaporization unit 3, and the passages 7 having the uniform passage areas s1 to sn can be formed in the vaporization unit 3. Accordingly, the liquid material L is ensured to smoothly flow in the passage 7, retention time thereof is prolonged, and the liquid material L can be brought into contact with the dividers 8 for a longer time, so that the liquid material L can be more reliably vaporized.
Furthermore, when ½ of the width W or the depth D of the passage 7 is in the range of the temperature boundary layer of the liquid material L, the temperature of the liquid material L flowing in the passage 7 can be reliably increased to the vaporization temperature of the liquid material L or more, before the liquid material L reaches passage outlets 7b. In other words, no liquid material L remaining in a low-temperature and liquid state is discharged from the passage outlets 7b. All the liquid material L is reliably vaporized and heads to the vaporized material discharge port 21 through the passage outlets 7b.
Hereinafter, the present invention will be described with reference to the drawings. A vaporizer A of the present invention is, for example, equipment that is used in a semiconductor manufacturing system, and includes: a liquid material introduction port 11; a carrier gas introduction port 12, which is provided as necessary; a vaporized material discharge port 21; a vaporizer body 1 in which a passage 7, into which a liquid material L flows, is formed in a vaporization unit 3 extending from the liquid material introduction port 11 to the vaporized material discharge port 21; and a heater 5 that heats the liquid material L flowing in the passage 7.
The vaporizer A of the present invention is required to quickly discharge, from the passage 7, a vaporized material G2 having a volume rapidly expanded through vaporization, to suppress an increase in internal pressure in the passage 7, and enable vaporization of the liquid material L to be promoted without delay, as described above. Therefore, the passage 7 of the vaporization unit 3 is basically formed such that a passage area S represented by a cross-sectional area of the passage 7 (when a plurality of the passages 7 are provided, the sum of the cross-sectional areas s1+ . . . +sn of the plurality of passages 7) orthogonal to a flowing-through direction of the liquid material L is increased toward the vaporized material discharge port 21 from the liquid material introduction port 11.
Here, “the passage area S of the passage 7 is increased toward the vaporized material discharge port 21 from the liquid material introduction port 11” includes the following cases: (1) the passage area S of one passage 7 is simply increased (gradually increased); (2) when the plurality of passages 7 are provided and the passage areas of the passages 7 are represented by s1 to sn, the total passage area S obtained by adding up the passage areas s1 to sn on a horizontal line HL at a right angle to a centerline CL of the vaporization unit 3 is increased (gradually increased); and (3) the passage 7 branches and the number of the passages 7 is increased toward the downstream side, that is, the increased number of the passages 7 increases (gradually increases) the total passage area S.
In addition, a “range” in which the passage area S of the passage 7 is increased toward the vaporized material discharge port 21 from the liquid material introduction port 11 may extend over the entire length of the vaporization unit 3 including the passage 7 therein, but may also end when the temperature of a gas material G2 reaches a predetermined temperature and the gas material G2 no longer expands.
In addition, examples of a method for supplying the liquid material L include: a case where a carrier gas G1 is used and the liquid material L is atomized and supplied to the vaporization unit 3; and a case where no carrier gas G1 is used and only the liquid material L is supplied to the vaporization unit 3.
In a first embodiment of the vaporizer A, dividers 8 each have an “island shape” formed in a polygonal shape, or a circular or oval shape. The first embodiment will be described below, using a case where the dividers 8 each have a hexagonal shape out of the above shapes and are arranged in a tortoiseshell manner as a representative example (first mode of the first embodiment), and using the other cases as second, third, and fourth modes of the first embodiment. Even among the cases, a case where the carrier gas G1 is used and a case where only the liquid material L is used will be described separately.
The “tortoiseshell manner pattern” is a pattern in which hexagons are arranged in multiple stages and multiple rows in a zigzag manner, and that the hexagons at a lower stage are arrayed between the hexagons at an upper stage. It is needless to say that the passage 7 is formed between the hexagonal dividers 8.
An example shown in
The first mode of the first embodiment shown in
The vaporizer body 1 includes a plate-shaped base plate 2 and a plate-shaped cover plate 10, and the cover plate 10 is bonded (e.g., diffusion bonded) over the entirety of one surface (to-be-covered surface 2a) of the base plate 2. The base plate 2 and the cover plate 10 are formed of a corrosion-resistant metal such as stainless steel. The above diffusion bonding is a method for bonding the cover plate 10 and the base plate 2, which are metal plates, by heating the plates to a high temperature under a vacuum and applying a load under high pressure. The bonded part is completely hermetically bonded. The vaporizer body 1 has a plate-shaped appearance.
On the to-be covered surface 2a, covered by the cover plate 10, of the base plate 2, grooves (trenches) forming the passage 7, and an introduction space 4a and a discharge space 4b described below are formed. A part in which the passage 7 is formed is referred to as vaporization unit 3. The passage 7, the introduction space 4a, and the discharge space 4b are hermetically covered by the cover plate 10.
The shape of the vaporization unit 3 is an isosceles triangle shape in a plan view, and a vaporization unit starting end 3a is located at the top of the vaporization unit 3. In the drawings, the introduction space 4a is provided on an upper side of the vaporization unit starting end 3a and extends in the up-down direction, and the vaporization unit starting end 3a is connected to a lower end of the introduction space 4a. The liquid material introduction port 11 is provided to the introduction space 4a. In this embodiment, the carrier gas introduction port 12 is further provided on the vaporization unit starting end 3a side, and a spraying function by the carrier gas G1 is ensured in the introduction space 4a. The liquid material introduction port 11 and the carrier gas introduction port 12 are formed in an upper end portion of the back surface of the base plate 2.
When the above carrier gas introduction port 12 is provided and the carrier gas G1 is used, introduction of the liquid material L and discharge of the gas material G2 can be advantageously performed quickly (in the contrary case, when only the liquid material L is supplied and no carrier gas G1 is used as described below, the carrier gas introduction port 12 is unnecessary).
At a vaporization unit end 3b, which is the base of the vaporization unit 3, a plurality of passage outlets 7b are open, and the plurality of passage outlets 7b are connected to the discharge space 4b. The vaporized material discharge port 21 is provided to the discharge space 4b. The discharge space 4b and the passage area of the vaporized material discharge port 21 are each larger than the total passage area S of a plurality of passages 7 that are open to the discharge space 4b so that discharge of the vaporized material G2 having flowed out of the plurality of passages 7 is not obstructed. The vaporized material discharge port 21 is formed in a lower end portion of the back surface of the base plate 2.
Next, detailed structures (i.e., the sizes and the shapes the divider 8 and the passage 7) of the vaporization unit 3 are properly selected according to the type or the usage of a product, or physical properties (viscosity, specific heat, vaporization heat, molecular weight, vapor pressure, etc.) of the liquid material L to be vaporized. In the embodiment, regarding the shape and the arrangement of the dividers 8, the dividers 8 each have a regular hexagonal shape and are arranged in a tortoiseshell manner, as described above. Other forms will be described in detail below. The size of each of the dividers 8 will be described below.
Next, regarding the size of the passage 7, the passage 7 is surrounded by wall surfaces 7h and is heated from the entire periphery thereof, and thus, as described below, it is preferable that ½ of at least one of a width W and a depth D of the passage 7 does not exceed a “temperature boundary layer”, in which the liquid material L has a fixed temperature, from the wall surface 7h. It is extremely difficult to vaporize the high-boiling-point and low-vapor-pressure liquid material L, but, for the above, heat transfer to the liquid material L can be improved and vaporization can be facilitated.
The “temperature boundary layer” refers to a range in which the liquid material L flowing away from the wall surface 7h has a uniform flow temperature. That is, assuming that the temperature of each wall surface 7h, of the base plate 2 or the cover plate 10, facing the passage 7 is a wall surface temperature, the temperature of a fluid flowing in the passage 7 decreases as a distance from the wall surface 7h increases, but is fixed (uniform flow temperature) when reaching a certain temperature. In this case, the entire periphery of the passage 7 is surrounded by the wall surfaces 7h. Thus, when a range from each wall surface 7h to the center of the passage 7 is set to be equal to or smaller than a range of the “temperature boundary layer”, all the liquid material L flowing in the passage 7 is heated to the vaporization temperature and any liquid material L remaining in a liquid state does not pass through the passage 7.
That is, with the wall surface temperature being set such that the temperature of the “temperature boundary layer” is higher than the vaporization temperature, all the liquid material L flowing in the passage 7 is vaporized.
The passage 7 is formed so as to branch in the vaporization unit 3 and such that the number of the passages 7 is increased toward the vaporization unit end 3b from the vaporization unit starting end 3a. The increased number of the passages 7 increases the passage area S.
The passage area S is preferably increased over the entire length of the vaporization unit 3. However, as long as discharge of the vaporized material G2 having a volume sharply increased through vaporization is not obstructed, the passage area S need not be increased over the entire length of the vaporization unit 3. Although not shown, in a portion, near the vaporization unit end 3b, in which the temperature of the vaporized material G2 flowing in the vaporization unit 3 becomes close to the predetermined temperature and the volume expansion thereof stops, the passages 7 may extend straight toward the passage outlets 7b without branching, and an increase in the passage area S may stop at the portion.
The passage area S refers to the cross-sectional area of the passage 7 orthogonal to a flow direction of the liquid material L (when a plurality of the passages 7 are provided, the sum of the cross-sectional areas).
As shown in
A planar shape of the vaporization unit 3 (in a plan view state in which the cover plate 10 is removed) is, for example, a triangle shape (isosceles triangle shape in the drawing) having a width increased toward the vaporization unit end 3b from the vaporization unit starting end 3a. The introduction space 4a that communicates with the vaporization unit starting end 3a and extends upward from the vaporization unit starting end 3a, is provided at the top of the vaporization unit 3, the passage 7 extending from the top of the introduction space 4a to the base of the vaporization unit 3 is formed inside the vaporization unit 3, and the discharge space 4b to which the passage outlets 7b of the passages 7 are open is provided at the base.
The passage 7 provided in the vaporization unit 3 has one passage inlet 7a at the vaporization unit starting end 3a, and branches toward the vaporization unit end 3b from the vaporization unit starting end 3a, so that the passage outlets 7b of the plurality of passages 7 are open to the discharge space 4b at the vaporization unit end 3b as described above.
Out of the passages 7 formed by branching on the upstream side, the passages 7 adjacent to each other join and are connected to each other on the downstream side. The portions surrounded by the passage 7 are the dividers 8. In other words, branching of the passage 7 is caused by the dividers 8 provided in the vaporization unit 3. The dividers 8 are provided such that the number thereof is increased toward the vaporization unit end 3b from the vaporization unit starting end 3a. Accordingly, the plurality of passages 7 are open at the vaporization unit end 3b as described above.
The dividers 8 of the embodiment each have a hexagonal shape in a plan view (regular hexagonal shape in the drawings) as described above, and are arranged at regular intervals in a tortoiseshell manner. Therefore, the passage 7 formed between the dividers 8 and the passage 7 formed between the outside divider 8 and the side wall of the base plate 2 each have the same width W and depth D from the vaporization unit starting end 3a to the vaporization unit end 3b.
The passage 7 is configured as a groove having a rectangular cross section as shown in
Grooves forming the passage 7, the introduction space 4a, and a discharge space 4b are produced by machining or chemical etching.
Each divider 8 is formed in order to smoothly transmit heat from the heater 5 to the liquid material L flowing in the passage 7 via the base plate 2 or the cover plate 10, and thus may be formed in any shape that does not obstruct such heat transmission. Therefore, the planar shape of the divider 8 is not particularly limited, and examples of the planar shape include a polygon (a triangle, a rectangle, a pentagon, a hexagon, a heptagon, an octagon, or polygon with more angles), and a circle or an oval. Out of these, from the viewpoint of smoothing the flow of a fluid (liquid material L or gas material (gas) G2), hexagons (regular hexagons in the drawings) are most preferably arranged in a tortoiseshell manner, and such arrangement is used as the embodiment. Considering the above, a range in which a width 8w (and a height 8h) of the divider 8 is 10 mm+5 mm is appropriate.
If the number of the dividers 8 is increased toward the vaporization unit end 3b from the vaporization unit starting end 3a, the arrangement structure thereof is also not particularly limited. However, each divider 8 (particularly, corner portion thereof) on the downstream side is preferably arranged just below the passage 7 on the upstream side such that the flow of the passage 7, on the upstream side, between the dividers 8 on the upstream side is equally divided to the left and right. In the present embodiment, as one example, the dividers 8 are arranged in a tortoiseshell manner.
In addition, to facilitate dividing the flow of the passage 7 on the upstream side and to generate no stagnation in the flow of the fluid (liquid material L or vaporized material G2), one of the corners of the hexagonal divider 8 is set so as to be arranged just below the passage 7 on the upstream side. It is needless to say that the same applies to another polygon.
In the embodiment shown in
A temperature sensor 6 is mounted in the vicinity of the bar-shaped heater 5.
The liquid material L is stored in the material tank T, and the liquid material L is sent out to the liquid flow rate controller E by the pressurized gas G0.
The liquid flow rate controller E is connected to the material tank T, and sends out the liquid material L, supplied from the material tank T, by a constant fixed mass flow rate to the liquid material introduction port 11 of the vaporizer A.
The mass flow rate controller P is connected to the carrier gas supply source, and sends out the carrier gas GI by a mass flow rate to the carrier gas introduction port 12 of the vaporizer A.
The liquid material introduction port 11 of the vaporizer A is connected to the liquid flow rate controller E via the liquid material supply piping, and the mass flow rate controller P is connected to the carrier gas introduction port 12 via the carrier gas supply piping. The vaporized material discharge port 21 is connected to, for example, the reaction furnace R for oxidation of a silicon substrate via a vaporized material supply piping.
The material tank T, the liquid material supply piping from the material tank T to the vaporizer A via the liquid flow rate controller E, the vaporizer A, the liquid flow rate controller E, and the vaporized material supply piping are kept warm.
The vaporizer A has a flat-plate-like outer shape, and thus is not voluminous even if being directly mounted to the reaction furnace R.
Next, operation of the vaporizer A of the present invention will be described. When the heater 5 of the vaporizer A is energized and increases the temperature, heat is transmitted to a portion around the passage 7.
In this state, the pressurized gas G0 is supplied to the material tank T, and the liquid material L is supplied by a constant mass flow rate from the liquid flow rate controller E to the liquid material introduction port 11 of the vaporizer A as described above. Meanwhile, similarly, the carrier gas G1 is injected by a mass flow rate from the mass flow rate controller P into the carrier gas introduction port 12, and the liquid material L, which has been atomized, is injected from an outlet of the introduction space 4a, that is, the vaporization unit starting end 3a, into the vaporization unit 3.
The atomized liquid material L injected into the vaporization unit 3 hits the divider 8 in the first row located at the vaporization unit starting end 3a. In the present embodiment, since each divider 8 has a hexagonal shape and one of the corners thereof is oriented to the introduction space 4a side, the jetted atomized liquid material L is equally divided to the left and right at the corner. The atomized liquid material L that has branched to the left and right flows along the passages 7 formed around the first divider 8.
The divided atomized liquid material L flows in the passages 7 formed between the divider 8 in the first row and an inner wall of the vaporization unit 3, and reaches the second row. In the second row, each half of the divided atomized liquid material L flows in the passage 7 between the divider 8 in the second row and the first divider 8, joins the other half thereof at an end portion of the divider 8 in the first row, flows in the passage 7 between the dividers 8 in the second row as it is, and again branches at an upper end corner portion of the dividers 8 in the third row.
The remaining atomized liquid material L, which has flowed on the outside in the second row, flows along the inner wall of the vaporization unit 3. Subsequently, division and joining of the flow is repeated by successively repeating the above.
The divided atomized liquid material L is rapidly heated by coming into contact with the wall surface 7h of the passage 7 or by heat from the wall surface 7h, and is sequentially vaporized in the flow. When the size (width W or depth D) of the passage 7 is in the range of the “temperature boundary layer” (a range not exceeding double the “temperature boundary layer” at most), the entire inside of the passage 7 is maintained at the vaporization temperature or higher to vaporize all the atomized liquid material L in the flow, and such a short circuit phenomenon that fine particles remaining in a liquid state pass through the passage 7 and reach each passage outlet 7b does not occur.
The atomized liquid material L is sequentially vaporized in the flow and then the volume thereof rapidly expands. However, the passage 7 is continuous so as to form a mesh pattern, the passage area S thereof is sharply increased toward the vaporization unit end 3b, and thus the vaporized material G2 flows so as to be divided in the passage 7 and does not increase the internal pressure in the passage 7. Therefore, since the internal pressure in the passage 7 is not increased, the liquid material L smoothly flows in the vaporization unit 3 and is vaporized.
Each passage 7 changes the direction at short intervals as described above, and thus a fluid (atomized liquid material L or vaporized material G2) is agitated and the chance that the fluid is brought into contact with the wall surface 7h is dramatically increased, leading to quick temperature increase.
The vaporized material G2 flows into the discharge space 4b through each passage outlet 7b, and is supplied to the reaction furnace R through the vaporized material discharge port 21 formed in the discharge space 4b without increasing the internal pressure inside the equipment.
A case where the carrier gas G1 is used has been described above, and a case where no carrier gas G1 is used will be described next.
When no carrier gas G1 is used, the liquid material L drops or flows down as it is, comes into contact with the divider 8 in the first row, and is divided to the left and right as described above. The flow of the liquid material Lis the same as in the above, but the liquid material L flows mainly in the passages 7 around the dividers 8 in a middle portion arrayed along the centerline CL in this case.
Then, the vaporized material G2 vaporized in the flow is diffused into both the passages 7, and flows out into the discharge space 4b evenly through the passage outlets 7b.
In this case, each divider 8 has a shape other than a hexagonal shape. If the dividers 8 each have a circular shape, as in a tortoiseshell pattern, the dividers 8 are arranged such that each circular divider 8 on the downstream side is located just below the passage 7 between the circular dividers 8 on the upstream side (
Accordingly, as in the above, the atomized liquid material L jetted into the vaporization unit 3 together with the carrier gas G1 is caused to branch at each circular divider 8 and flows downstream, and is vaporized in the meantime. In this case, the size of the each passage 7 formed between the circular dividers 8 is not constant. Compared to a portion in which the circular dividers 8 are close to each other, the interval between the circular dividers 8 is increased and the flow speed is decreased at a flow dividing portion, thereby forming minute vortexes. If a minute turbulent flow is generated at this portion, the flow speed is decreased and the chance that the wall surface 7h and the material (liquid material L or vaporized material G2) are brought into contact with each other is increased, leading to rapid temperature increase.
In this case, each divider 8 has a triangle shape (equilateral triangle shape in
Each passage 7 is formed so as to have the same width W and the depth D in the entire vaporization unit 3.
In this case, each divider 8 has a rectangle shape (square shape in
In this case as well, each passage 7 is formed so as to have the same width W and the same depth D in the entire vaporization unit 3.
This is an example in which one (not shown) to a plurality of the passages 7 are provided toward the vaporization unit end 3b from the vaporization unit starting end 3a. The passage 7 is formed so as to have the passage area S increased toward the vaporized material discharge port 21 from the liquid material introduction port 11. In the drawing, each passage 7 is formed such that the depth D is in the range of the “temperature boundary layer” (is in a range not exceeding double the “temperature boundary layer” at most) and such that the width W is increased.
The passage area S of the passage 7 is increased over the entire length of the passage 7 as described above or on the upstream side relative to where vaporization of the liquid material L finishes.
Each passage 7 in the drawing is formed linearly, and the wall surface 7h thereof may be provided with a concave-convex pattern as shown in an enlarged view. Accordingly, the area of contact between the liquid material L and the wall surface 7h of the passage 7 is increased and the flow speed of the liquid material L flowing thereon becomes slow, leading to quick temperature increase of the liquid material L.
In addition, when the plurality of passages 7 are provided, a bypass 7p connecting the adjacent passages 7 is preferably provided. The liquid material L and the vaporized material G2 intercommunicate between the adjacent passages 7 through the bypass 7p, and the internal pressure in the vaporization unit 3 is equalized.
Although not shown, the passage 7 may be meandered.
As described above, the vaporizer A of the present invention is configured to have the increased passage area S (increased number) of the passage 7 toward the downstream side. Thus, even when the volume of the liquid material L is increased through vaporization thereof, an increase in the internal pressure in the passage 7 is suppressed and the liquid material Lis efficiently vaporized. Therefore, the vaporizer A can also be downsized, and be easily mounted to the reaction furnace R (film formation device). The structure of the vaporizer A is extremely simple, thereby enabling cost reduction in conjunction with downsizing.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-166820 | Oct 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/041556 | 11/11/2021 | WO |
