Vaporizer

Abstract

To provide a vaporizer that is reducible in occupation area (footprint) while maintaining a large heat transfer area as compared with its size.SOLUTION: A vaporizer A comprises: a casing 1 which internally has an atomization space 10 supplied with atomized raw material mist M, a vaporized raw material discharge path 30 discharging a vaporized raw material G3 containing a vaporized component toward a next process 140, and a heat transfer enhancement space 20 linking the atomization space 10 to the vaporized raw material discharge path 30 to vaporize the mist M; a heater H for heating; and an atomizer 40 which atomizes a liquid raw material L and supplies it to the atomization space 10. The casing 1 and atomization space 10 have plate-like outer shapes. The heat transfer enhancement space 20 is provided with a plurality of heat transfer projections 21 which come into contact with circulated heated gas G2 to vaporize the mist M contained in the heated gas G2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vaporizer that is thin, has a small footprint, and has excellent vaporization efficiency.

Background Art

[0002] Vaporizers that vaporize a liquid raw material with mass flow control and supply it as a vaporized raw material to the next process at its accurate mass flow rate are used in various fields. One example of its application is the semiconductor manufacturing process. As semiconductor manufacturing equipment, there are, in particular, atmospheric pressure or reduced pressure CVD equipment for forming a thin film on the surface of a wafer. In recent state-of-the-art processes, ALD (Atomic Layer Deposition / single atomic layer film vapor phase growth) is often used, and the vaporizer of the present invention is used in such equipment. In such equipment, due to requirements such as miniaturization of the equipment and multi-sources, there is a need for a vaporizer with excellent vaporization efficiency and a small footprint.

[0003] Conventionally, there is a vaporizer for vaporizing and supplying a liquid raw material to a CVD apparatus as disclosed in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The vaporizer described in Patent Document 1 includes a heater, a cylindrical vaporization chamber, and an atomizing nozzle. A liquid raw material with mass flow control is brought into contact with a carrier gas that is jetted at high speed from the atomizing nozzle, blown into the vaporization chamber as an atomized raw material mist, and evaporated in a vaporization space maintained at a high temperature, and then carried to the next process together with the carrier gas. In this type of vaporizer, the surface area per unit volume of the raw material mist increases rapidly due to atomization, making it very easy to vaporize, and complete vaporization of the liquid raw material becomes possible. Moreover, it can be applied in a wide range from small capacity to large capacity, and is said to be a liquid vaporization feeder that can fully cope with the manufacture of next-generation semiconductors. However, when miniaturized, it becomes concentrically and evenly sized, and the heat transfer area (the area of the inner surface of the vaporization chamber) of the cylindrical vaporization chamber decreases rapidly. Therefore, no matter how atomized it is, the ability to vaporize the blown atomized raw material mist decreases rapidly. In other words, a vaporizer having a cylindrical vaporization chamber cannot be made smaller while maintaining its vaporization ability.

[0006] The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a vaporizer capable of reducing the occupied area (footprint) while maintaining a large heat transfer area compared to the size.

Means for Solving the Problems

[0007] Claim 1 is as follows: A spraying space 10 into which an atomized raw material mist M obtained by atomizing a liquid raw material L is supplied; A vaporized raw material discharge path 30 that is disposed adjacent to the spraying space 10 and discharges a vaporized raw material G3 containing a vaporized component of the atomized raw material mist M toward the next process 140; A heat transfer promotion space 20 that is provided between the spraying space 10 and the vaporized raw material discharge path 30 so as to communicate with both, and supplies heat to a heated gas G2 containing the atomized raw material mist M flowing from the spraying space 10 to the vaporized raw material discharge path 30 to vaporize the atomized raw material mist M, and a casing 1 incorporating the same; A heater H for heating provided in the casing 1; A vaporizer A is configured by an atomizer 40 installed in the casing 1 and configured to supply the liquid raw material L in a mist form to the spray space 10. The casing 1 has a plate-like outer shape with a width W larger than the thickness T. The spray space 10 has an inner dimension w in the width direction 10 relative to the inner dimension t in the thickness direction 10 and has a plate-like shape. In the heat transfer promotion space 20, a plurality of , configured in a polygon, circle or ellipse when viewed from the side of the plate surface 1a of the casing 1 heat transfer protrusions 21 are provided to contact the flowing heated gas G2 and vaporize the atomized raw material mist M contained in the heated gas G2. in two or more rows It is characterized by being provided. , the heat transfer protrusions 21 in the row on the vaporization raw material discharge path 30 side are arranged in the middle of the heat transfer protrusions 21 in the row on the spray space 10 side, and the flow path 22 of the heated gas G2 surrounding the heat transfer protrusions 21 is formed between adjacent heat transfer protrusions 21

[0008] Claim 2 is the vaporizer A according to claim 1, An atomizer mounting hole 5 for mounting the atomizer 40 is provided on the upper surface of the casing 1, the spray space 10 is vertically long rectangular, and a ceiling portion 10t connected to the atomizer mounting hole 5 It has a rectangular plate-like shape including left and right side surfaces 10a and 10b and a bottom surface 10c. Heat transfer promotion spaces 20 are respectively formed along the both side surfaces 10a and 10b and the bottom surface 10c. The pressure losses of the heated gas G2 flowing through the side heat transfer promotion spaces 20a and 20b along the both side surfaces 10a and 10b and the pressure loss of the heated gas G2 flowing through the bottom heat transfer promotion space 20c along the bottom surface 10c are set to be equal to each other. It is characterized by this.

[0010] Claim 3 depends on Claim 1 in the vaporizer A according to When the heat transfer protrusion 21 is polygonal, it is installed such that the corner part faces the spray space 10 side. When it is elliptical, it is installed such that the arc side with a smaller radius faces the spray space 10 side. It is characterized by this.

[0012] Claim 4 depends on Claims 1 to 3 in any one of the vaporizer A according to The atomizer 40 has an inner pipe 41 that opens into the spray space 10 and supplies the liquid raw material L to the spray space 10. It is arranged so as to surround the periphery of the inner pipe 41, and between the outer surface of the inner pipe 41, a carrier gas G1 supplied passes through, and is formed by an outer pipe 45 that forms an ejection gap 48 of the carrier gas G1 for atomizing the liquid raw material L. The tip 41s of the inner pipe 41 is provided so as to be positioned inside the outer pipe tip 45s of the outer pipe 45.

[0013] Claim 5 depends on Claim 4 In the vaporizer A described in (FIG. 16), Guide protrusions 49 extending into the spray space 10 from the outer pipe tip 45s of the outer pipe 45 are provided at positions sandwiching the tip 41s of the inner pipe 41 from both sides along the opposing inner surfaces 15 of the casing 1 that constitutes the spray space 10.

Effect of the Invention

[0014] According to the invention described in claim 1, the casing 1 has a plate-like outer shape in which the width W is large with respect to the thickness T, and the spray space 10 has an inner dimension t in the thickness direction 10 with respect to the inner dimension w in the width direction 10 Since it has a plate-like shape that is large, the heat transfer area facing the spray space 10 and the heat transfer promotion space 20 provided inside the casing 1 becomes significantly larger than the heat transfer area of a cylindrical vaporizer of the same capacity, and the vaporization ability increases. As a result, compared with a cylindrical vaporizer of the same capacity, the occupied area (footprint) of the vaporizer A of the present invention becomes smaller.

[0015] In the above invention, since the rectangular plate-like spray space 10 is provided with side heat transfer promotion spaces 20a and 20b and a bottom heat transfer promotion space 20c, the atomized raw material mist M blown into the spray space 10 becomes a heated gas G2 together with the carrier gas G1 blown in for atomization and flows out from three directions of the spray space 10, enabling rapid complete vaporization. Moreover, since the pressure losses of the heated gas G2 flowing in these three directions are set to be equal to each other, a short circuit of the heated gas G2 does not occur in any case, and vaporization leakage of the atomized raw material mist M can be avoided.

[0016] In the above invention, if the corner portion of the heat transfer protrusion 21 is installed so as to face the spray space 10 side, or in the case of an ellipse, if the arc side with a smaller radius faces the spray space 10 side, the inflow of the gas G2 to be heated from the spray space 10 side becomes smooth. In addition, when the heat transfer protrusion 21 is hexagonal, the flow path 22 of the gas G2 to be heated formed between adjacent heat transfer protrusions 21 can have the same width throughout, and the pressure loss in the heat transfer promotion space 20 can be made uniform without generating stagnation in the flow of the gas G2 to be heated.

[0017] In the above invention, when the heat transfer protrusions 21 are arranged in multiple rows, if the heat transfer protrusions 21 in the row arranged on the vaporization raw material discharge path 30 are installed so as to be positioned between the heat transfer protrusions 21 in the row arranged on the spray space 10 side with respect to the heat transfer protrusions 21 in the row arranged on the spray space 10 side, the flow of the gas G2 to be heated provided between the heat transfer protrusions 21 can be made to meander, and the vaporization of the gas G2 to be heated can be promoted.

[0018] In the above invention, if the tip 41s of the inner tube 41 is positioned inside the outer tube tip 45s of the outer tube 45, the carrier gas G1 ejected from the ejection gap 48 between the inner tube 41 and the outer tube 45 can effectively atomize the liquid raw material L flowing out from the tip 41s of the inner tube 41.

[0019] In the above invention, if the guide protrusion 49 is formed so as to extend into the spray space 10 along the inner surface 15, it is possible to prevent the atomized raw material mist M from scattering to the inner surface 15 side and increase the amount of the atomized raw material mist M scattered into the spray space 10.

Brief Description of the Drawings

[0020]

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Figure 18

Mode for Carrying Out the Invention

[0021] Hereinafter, the present invention will be described in detail according to the illustrated embodiments. FIG. 18 is an example of a liquid vaporization supply device 100 incorporating a vaporizer A of the present invention. Here, the liquid vaporization supply device 100 vaporizes the liquid raw material L supplied from the raw material tank 120 to make it a vaporized raw material G3, and supplies the vaporized raw material G3 after vaporization to a reactor 140 such as a CVD device in the next process. It includes a vaporizer A, a raw material tank 120, a liquid mass flow meter 110, a mass flow controller 130, etc., and these devices are connected to each other via pipes.

[0022] The vaporizer A of the present invention is roughly composed of a casing 1, an atomizer 40, and a heater H. FIGS. 1 to 3 are an example thereof.

[0023] The casing 1 is a vertically long rectangular plate-shaped member in the illustrated embodiment, and is composed of a pair of front and rear casing constituent members 2 and 3 assembled in a nested manner. A spray space 10, a heat transfer promotion space 20, a vaporized raw material discharge path 30, and an atomizer mounting hole 5 are dug and provided on the mating surface thereof. The atomizer mounting hole 5 is provided on the upper surface of the casing 1, and as can be seen from FIGS. 1 and 2, the atomizer 40 is mounted on this part.

[0024] One of the casing constituent members 2 constituting the casing 1 has a concave portion in the central part of the inner surface, and the other casing constituent member 3 has a convex portion rising in the central part of the inner surface, and the convex portion 3a is fitted into the concave portion 2a. An airtight sealing material 9 such as an O-ring is fitted around the concave portion 2a and the convex portion 3a except for the atomizer mounting hole 5. And heaters H are installed on the casing constituent members 2 and 3 respectively. In the illustrated embodiment, there are two upper and lower stages, but of course, it is not limited to this, or it may be one, or a plurality of three or more stages, or one or a plurality of vertical heaters may be provided on the left and right casing constituent members 2 and 3. On the mating surface of the concave portion 2a and the convex portion 3a, recesses constituting the spray space 10, the heat transfer promotion space 20, and the vaporized raw material discharge path 30 are provided as described above.

[0025] The atomizer mounting hole 5 is a circular stepped hole that opens on the upper surface of the casing 1 (i.e., the casing component members 2 and 3 that are fitted by the concave portion 2a and the convex portion 3a and bolted), and its lower end is connected to the spraying space 10. An atomizer 40 is mounted in this atomizer mounting hole 5, a gas reservoir 7 is provided around an outer tube 45 of the atomizer 40 to be described later, and a carrier gas supply hole 8 is connected to this gas reservoir 7. A mass flow controller 130 is connected to the carrier gas supply hole 8 via a pipe.

[0026] The atomizer 40 is a double tube including an inner tube 41 and an outer tube 45. The inner tube 41 is a cylindrical member protruding from the center of a circular first flange portion 43, and a nozzle hole 44 is drilled over the entire length along its center line. As shown in FIG. 13, the outer peripheral shape of the tip portion of the inner tube 41 is formed in a tapered shape that tapers toward the tip, and a thin cylindrical inner tube tip portion 42 is provided at the tip. The nozzle hole 44 is composed of a main hole portion 44a having a thick inner diameter and a supply hole 44b provided in the inner tube tip portion 42 with a smaller inner diameter than the main hole portion 44a, and the liquid raw material L supplied from this supply hole 44b flows out or drips.

[0027] The outer tube 45 is a hollow cylindrical member protruding from the hole edge of a ring-shaped second flange portion 47, and an inner tube insertion hole 45a into which the inner tube 41 is inserted is drilled along its center line. The second flange portion 47 is fastened to the first flange portion 43 with bolts (not shown) and integrated. A gap is formed between the outer tube 45 and the inner tube 41 fastened as described above. This gap is used as a jet gap 48 from which the carrier gas G1 jets out.

[0028] The inner surface shape of the inner tube insertion hole 45a of the outer tube 45 is made to match the outer diameter shape of the inner tube 41. The inner surface of the tip portion of the inner tube insertion hole 45a is formed in a conical concave surface to match the conical outer surface of the tip portion of the inner tube 41. Further, an outlet portion 45b into which the inner tube tip portion 42 of the inner tube 41 is inserted is a circular hole parallel to the outer surface of the inner tube tip portion 42. The outer tube 45 and the inner tube 41 are integrated by bolting the second flange portion 47 to the first flange portion 43 as described above. However, by sandwiching a thin shim (not shown) between the two and then bolting them together, the distance of the ejection gap 48 between the trumpet-shaped portion of the inner tube insertion hole 45a and the conical portion of the inner tube 41 can be adjusted.

[0029] Regarding the relationship between the tip portion 42 of the inner tube and the outlet portion 45b of the inner tube insertion hole 45a of the outer tube 45, the tip 41s of the cylindrical tip portion 42 of the inner tube is located inside the outer tube tip 45s which is the outlet portion 45b of the inner tube insertion hole 45a. The carrier gas G1 jets out along the outer surface of the cylindrical tip portion 42 of the inner tube so as to surround the entire circumference of the liquid raw material L flowing out or dripping from the tip 41s of the tip portion 42 of the inner tube, atomizing the liquid raw material L.

[0030] As described above, a circular gas reservoir 7 is provided around the outer tube 45. A carrier gas supply hole 8 communicating with this gas reservoir 7 is drilled in the casing 1, and a pipe from an external mass flow controller 130 is connected to this carrier gas supply hole 8. And a communication hole 45c communicating with the gas reservoir 7 is drilled in the outer tube 45, and the carrier gas G1 is supplied to the ejection gap 48 through the communication hole 45c.

[0031] Taking an example of the spray space 10 of the casing 1, as shown in FIGS. 1 to 3, it is a plate-shaped space formed in accordance with the outer shape of the casing 1, wide in the left-right and up-down directions and narrow in the front-rear thickness direction. In other words, the spray space 10 is a rectangular plate shape with the inner dimension w in the width direction (or longitudinal direction) 10 being larger than the inner dimension t in the thickness direction. And the space main body portion 10h has a vertically long rectangular shape when viewed from the plate surface 1a of the casing 1, and its ceiling portion 10t is connected to the atomizer mounting hole 5. 10

[0032] When viewed from the plate surface 1a of the casing 1, the ceiling portion 10t has a substantially trapezoidal shape whose width gradually increases from the atomizer mounting hole 5 toward the space main body portion 10h. And the outlet hole 6 of the portion between the atomizer mounting hole 5 and the ceiling portion 10t is formed such that its inner diameter widens from the outlet of the atomizer mounting hole 5 toward the ceiling portion 10t. The shape of the spray space 10 is not limited to the above shape, and it may be horizontally long, square, disc-shaped, or other shapes. The inner dimension t in the front-rear thickness direction 10 compared to the inner dimension w in the left-right and / or up-down directions 10 Any shape may be used as long as it is a plate-shaped space with a large size. In the drawings, the inner dimension w 10 is taken as the horizontal direction.

[0033] When the space main body portion 10h of the spray space 10 is vertically long and rectangular as described above, heat transfer promoting spaces 20 communicating with both side surfaces and the bottom surface thereof are provided adjacent thereto. They are respectively referred to as side portion heat transfer promoting spaces 20a and 20b and a bottom portion heat transfer promoting space 20c. The inner dimension t in the thickness direction of the heat transfer promoting space 20 20 is significantly smaller than the inner dimension t of the spray space 10 10 and it is preferable for heat conduction to the atomized raw material mist M to stop the inner dimension t 20 within the range of the temperature boundary layer with a large temperature change with respect to the front and rear wall surfaces 25 of the heat transfer promoting space 20 (in this embodiment, when the temperature boundary layer is 0.25 mm, the inner dimension t 20 is from 0.5 mm to 0.25 mm). And heat transfer protrusions 21 described later are provided in the heat transfer promoting space 20.

[0034] A vaporized raw material discharge path 30 is formed around the heat transfer promoting space 20. The vaporized raw material G3 (a mixed gas of the carrier gas G1 and the vaporized gas of the atomized raw material mist M) vaporized therein flows through the heat transfer promoting space 20. When the space body part 10h of the spray space 10 is a vertically long rectangle (a horizontally long rectangle or a square), as described above, the heat transfer promotion space 20 includes side part heat transfer promotion spaces 20a and 20b corresponding to the side surfaces 10a and 10b of the space body part 10h respectively, and a bottom part heat transfer promotion space 20c is provided in communication with these on the bottom surface 10c. Further, side part vaporization raw material discharge paths 30a and 30b and a bottom part vaporization raw material discharge path 30c are provided in communication with the side part heat transfer promotion spaces 20a and 20b and the bottom part heat transfer promotion space 20c respectively. Note that the corner part 28 between the spray space 10 and the vaporization raw material discharge path 30 is a solid part.

[0035] And, the inner dimension t in the thickness direction of the vaporization raw material discharge path 30 30 is wider than the inner dimension t in the thickness direction of the heat transfer promotion space 20 20 and smaller than the inner dimension t in the thickness direction of the spray space 10. 10 It is formed to have a size intermediate between the spray space 10 and the heat transfer promotion space 20. Here, when the space body part 10h is a vertically long rectangle (a horizontally long rectangle or a square) as described above and a vaporization raw material outlet 38 is provided in the bottom part vaporization raw material discharge path 30c, it is preferable to form the inner dimensions t in the thickness direction of the side part heat transfer promotion spaces 20a and 20b and the bottom part vaporization raw material discharge path 30c to be different. That is, on the side of the side part heat transfer promotion spaces 20a and 20b, since the pressure loss of the vaporization raw material G3 flowing through these must be considered, the inner dimension t in the thickness direction of the bottom part vaporization raw material discharge path 30c 30 is larger than these. In other words, in order not to impede the flow of the vaporization raw material G3 flowing through the side part heat transfer promotion spaces 20a and 20b, the inner dimension in the thickness direction t 30 of the bottom part vaporization raw material discharge path 30c is made large to facilitate the flow through the bottom part vaporization raw material discharge path 30c. To balance the pressure losses of the side part heat transfer promotion spaces 20a and 20b and the bottom part vaporization raw material discharge path 30c, it is not limited to only adjusting the inner dimension in the thickness direction, and it is also possible to make corresponding changes in the width direction. Note that in this embodiment, the inner dimension t in the thickness direction of the bottom part vaporization raw material discharge path 30c 30 is formed to be the same size as the inner dimension t in the thickness direction of the spray space 10. 30 is formed to be the same size as the inner dimension t in the thickness direction of the spray space 10. 10 When the space body portion 10h of the spray space 10 is disc-shaped, it is preferable that the inner dimension t in the thickness direction is gradually increased toward the vaporization raw material outlet 38. 30 It is preferable to gradually increase it.

[0036] In addition, in the vicinity of the side surfaces 10a and 10b and the bottom surface 10c of the space body portion 10h, tapered surfaces are formed that gradually decrease in their front-rear width toward the narrow side heat transfer promotion spaces 20a and 20b and the bottom heat transfer promotion space 20c. On the other hand, the outlet end surfaces of the side heat transfer promotion spaces 20a and 20b and the bottom heat transfer promotion space 20c to the side vaporization raw material discharge paths 30a and 30b and the bottom vaporization raw material discharge path 30c are flat surfaces perpendicular to the outlet.

[0037] In the heat transfer promotion space 20, as described above, in the heat transfer promotion space 20, the front-rear width of the heat transfer promotion space 20 (the inner dimension t in the thickness direction 20 ) is provided on either one of the front-side casing constituent member 2 or the rear-side casing constituent member 3, or heat transfer protrusions 21 are provided so as to be attachable from both sides with a thickness that is half of the front-rear width t of the heat transfer promotion space 20. 20 A plurality of heat transfer protrusions 21 are provided. The shape of the heat transfer protrusion 21 is configured as a polygon, a circle, or an ellipse when viewed from the plate surface 1a side of the casing 1. In the case of a polygon, a hexagon is preferable as will be described later. The heat transfer protrusions 21 are linearly arranged at regular intervals along the longitudinal direction of the side heat transfer promotion spaces 20a and 20b and the bottom heat transfer promotion space 20c. In the case of the illustrated embodiment, they are formed in a plurality of rows (two rows in the side heat transfer promotion spaces 20a and 20, and three rows in the bottom heat transfer promotion space 20c), but it is not limited to this, and one row may also be used. The spaces between the heat transfer protrusions 21 in the heat transfer promotion space 20 serve as the flow path 22 of the heated gas G2, and the pressure loss of the heated gas G2 flowing through these flow paths 22 is configured to be the same.

[0038] In the above configuration, when the space main body portion 10h is square or circular, the heat transfer protrusions 21 are arranged evenly in one row or multiple rows, and are adjusted so that the pressure loss of each flow path 22 is the same. (Of course, for the reasons described later, for the bottom portion, which is the front portion in the spraying direction, more rows may be provided than on both side portions.) However, when the shape of the space main body portion 10h is different from a square or a circle, specifically, when the shape of the space main body portion 10h is a vertically long rectangle (the same applies to a horizontally long rectangle), the bottom heat transfer promotion space 20c is located in the front in the spraying direction, and the mist M flows more easily than in the side heat transfer promotion spaces 20a and 20b. As described above, the inner dimension t in the thickness direction of the bottom vaporization raw material discharge path 30c 30 is larger than the inner dimension t in the thickness direction of the side heat transfer promotion spaces 20a and 20b. Therefore, the pressure loss of the heated gas G2 flowing from the bottom of the spraying space 10 through the flow path 22 of the bottom heat transfer promotion space 20c into the bottom heat transfer promotion space 20c is smaller than the pressure loss of the side heat transfer promotion spaces 20a and 20b. Thus, the number of rows of the heat transfer protrusions 21 in the bottom heat transfer promotion space 20c is increased to achieve equalization. 30 In addition, to equalize the pressure loss, it can be adjusted by the number of rows, but it can also be achieved by slightly changing the width of the flow path 22 on the side of the side heat transfer promotion spaces 20a and 20b and the width of the flow path 22 on the side of the bottom heat transfer promotion space 20c. The confirmation of the equalization of the pressure loss was performed by simulating the flow rate of the fluid in the flow path 22 using a computer. The arrows indicating the flow rate of the heated gas G2 in the flow path 22 shown in FIGS. 5 and 7 are in substantially the same state.

[0039]

[0040] In this embodiment, the heat transfer promotion space 20 is provided with multiple rows of heat transfer protrusions 21. In that case, it is preferable that the heat transfer protrusions 21 in the row on the side of the space main body portion 10h (this row is defined as the first row, and the rows toward the vaporization raw material discharge path 30 side are defined as the second row and the third row) are provided such that the heat transfer protrusions 21 in the row on the vaporization raw material discharge path 30 side (the second row) are located at intermediate positions. When providing the third row, it is provided to align with the first row. This is to make the flow path 22 meander as much as possible.

[0041] Figs. 5 to 11 show examples of the outer shape of the heat transfer protrusions 21. In Fig. 5, the heat transfer protrusions 21 are hexagonal, and their corners are arranged evenly up and down facing the space main body portion 10h of the spray space 10. As a result, the upper and lower sides of the heat transfer protrusions 21 in the side heat transfer promotion spaces 20a and 20b are arranged horizontally, and the left and right sides of the heat transfer protrusions 21 in the bottom heat transfer promotion space 20c are arranged vertically. And the heat transfer protrusions 21 of the second row are located in the middle of the heat transfer protrusions 21 of the first row. (The heat transfer protrusions 21 of the third row are located in the middle of the heat transfer protrusions 21 of the second row.) And all the flow paths 22 formed in the heat transfer promotion space 20 are provided with an equal cross-sectional area throughout. In the above case, the corners are arranged facing the space main body portion 10h side. Of course, it is not limited to this. Although not shown, the sides may be arranged facing the space main body portion 10h side. In this case, the flow paths 22 will not have an equal cross-sectional area throughout. In this case, it is preferable to make the portions with the minimum cross-sectional area that become the rate-determining step equal.

[0042] In Fig. 7, the heat transfer protrusions 21 are square, and one side of the heat transfer protrusions 21 of the first row is arranged facing the space main body portion 10h of the spray space 10. And the heat transfer protrusions 21 of the second row are located in the middle of the heat transfer protrusions 21 of the first row. (The heat transfer protrusions 21 of the third row are located in the middle of the heat transfer protrusions 21 of the second row.) And the cross-sectional area of the flow path 22 formed in the bottom heat transfer promotion space 20c is provided to be equal throughout. In the above case, an example where one side of the heat transfer protrusions 21 of the first row is arranged facing the space main body portion 10h side is shown. Of course, it is not limited to this. Although not shown, the corners may be arranged facing the space main body portion 10h side. In this case as well, the cross-sectional area of the flow path 22 is equal throughout.

[0043] In Fig. 9, the heat transfer protrusions 21 are circular, and in Fig. 10, the heat transfer protrusions 21 are diamond-shaped. The heat transfer protrusions 21 of the first row and the second row are at equal intervals, and the heat transfer protrusions 21 of the second row are located in the middle of the heat transfer protrusions 21 of the first row. (The heat transfer protrusions 21 of the third row are located in the middle of the heat transfer protrusions 21 of the second row.)

[0044] Figure 11 shows that the heat transfer protrusions 21 are equilateral triangles. The heat transfer protrusions 21 in the first row are arranged evenly up and down with their corners facing the space main body part 10h side, and the heat transfer protrusions 21 in the second row are located in the middle of the heat transfer protrusions 21 in the first row. (The heat transfer protrusions 21 in the third row are located in the middle of the heat transfer protrusions 21 in the second row.) And the corners of the heat transfer protrusions 21 in the second row are arranged to face the vaporization raw material discharge path 30 side. (Although not shown, of course, the heat transfer protrusions 21 in the second row may also be arranged so that their corners face the space main body part 10h side.) The above is an example of the shape and arrangement of the heat transfer protrusions 21, and the shape and arrangement are not limited to these.

[0045] The configuration of the liquid vaporization supply device 100 of the present invention has been briefly described first. Further explaining based on FIG. 18, a liquid mass flowmeter 110 is connected to the inner pipe 41 of the vaporizer A via a liquid raw material supply pipe 115. A raw material tank 120 is connected to the liquid mass flowmeter 110 via a pipe, and a pipe for introducing a push gas G0 is connected to the raw material tank 120. Although not shown, a control valve may be mounted on the inner pipe 41 of the atomizer 40 of the vaporizer A, and a liquid flowmeter may be used instead of the liquid mass flowmeter 110.

[0046] Also, a mass flow controller 130 is connected to the carrier gas supply hole 8 of the vaporizer A via a pipe, and a pipe for introducing a carrier gas G1 is connected to the mass flow controller 130.

[0047] Furthermore, a pipe for sending out a vaporization raw material G3, which is a mixed gas of the carrier gas G1 and the vaporized component of the atomized raw material mist M, is installed at the vaporization raw material outlet 38 of the vaporizer A, and this vaporization raw material G3 is sent out to a reactor 140 such as a CVD via this pipe.

[0048] The raw material tank 120 stores a liquid raw material L that is a raw material for the thin film. The liquid mass flowmeter 110 measures the mass flow rate of the liquid raw material L flowing through the pipe (the mass of the liquid raw material L flowing per unit time), and supplies the liquid raw material L with this mass flow rate to the vaporizer A based on the measurement result. The mass flow controller 130 adjusts the supply amount of the carrier gas G1 to the vaporizer A in terms of mass flow rate. Further, the reactor 140 functions as a "film forming means", and forms a thin film on the surface of the wafer by reacting the supplied vaporized raw material G3 with other gases (or by decomposing the vaporized raw material G3) using thermal energy, plasma energy, or the like.

[0049] Next, a method of vaporizing the liquid raw material L using the liquid vaporization supply apparatus 100 will be described. Hereinafter, as a representative example of the vaporizer A, the case where the heat transfer protrusions 21 are hexagonal is adopted. When the push gas G0 is supplied to the raw material tank 120, the pressure inside the raw material tank 120 rises, and the liquid level of the liquid raw material L is pushed down. As the push gas G0, an inert gas such as helium is used, for example. When the liquid level of the liquid raw material L is pushed down by the pressure of the push gas G0, the liquid raw material L flows through the pipe, passes through the liquid mass flow meter 110, and is supplied to the vaporizer A.

[0050] On the other hand, when the carrier gas G1 is supplied to the mass flow controller 130, the mass flow rate of the carrier gas G1 is controlled, and the carrier gas G1 having a predetermined mass flow rate is continuously supplied through the carrier gas supply hole 8 to the ejection gap 48 of the outer pipe 45 of the atomizer 40 of the vaporizer A.

[0051] The carrier gas G1 supplied to the ejection gap 48 of the outer pipe 45 is continuously and vigorously ejected from its outlet toward the spray space 10. Here, since the outlet of the ejection gap 48 is provided so as to surround the periphery of the inner pipe tip portion 42 of the inner pipe 41, the liquid raw material L flowing out or dripping from the tip 41s of the inner pipe tip portion 42 is atomized by the carrier gas G1 vigorously ejected from the ejection gap 48, and falls as mist while spreading in all directions.

[0052] The spray space 10 has the front - rear width (inner dimension t) as described above 10) is narrow, and is a wide plate-like space in the vertical and horizontal directions. Therefore, a considerable part of the atomized raw material mist M that spreads in the front and rear directions comes into contact with the inner surface 15 of the spray space 10. Since the heater H is built into each of the casing components 2 and 3, a considerable part of the atomized raw material mist M that has come into contact with the inner surface 15 is heated and vaporized. The remainder is vaporized by heat transfer from the inner surface 15 while flowing down the inner surface 15. On the other hand, since the atomized raw material mist M that has not come into contact with the inner surface 15 has a large spherical area relative to its fine volume, most of it rapidly vaporizes in the spray space 10 maintained at a high temperature. However, the large atomized raw material mist M may not be completely vaporized and may remain in the spray space 10.

[0053] These mixed gases (carrier gas G1, the remaining atomized raw material mist M, and the vaporized components of the atomized raw material mist M) in the spray space 10 flow into the flow path 22 of the heat transfer promotion space 20 from the spray space 10. This mixed gas flowing into the flow path 22 is designated as the gas to be heated G2. While passing through the flow path 22, the gas to be heated G2 undergoes heat transfer from the inner surface of the heat transfer promotion space 20 and the heat transfer protrusions 21, heat exchange by radiant heat, and heat exchange by collision with carrier gas molecules. As a result, all of the remaining mist is vaporized, and the entire amount is gasified and sent to the reactor 140.

[0054] Here, the operation of the hexagonal heat transfer protrusions 21 will be further described with reference to FIGS. 5 and 6. When the hexagonal heat transfer protrusions 21 are arranged evenly as shown in the figure, the flow path 22 has a Outlet uniform cross-sectional area from the entrance to, and moreover, meanders. As a result, the gas to be heated G2 comes into uniform contact with the hexagonal heat transfer protrusions 21 and is heated, vaporizing the remaining mist M. Moreover, the gas to be heated G2 flowing through the flow path 22 flows smoothly without forming stagnation. FIG. 5 shows the state of the flow of the gas to be heated G2 shown in FIG. 6 (the thin part is the part where the flow is fast, and the thick part is the slow part), and FIG. 5 is a diagram showing this with arrows. The hexagonal heat transfer protrusions 21 show an almost uniform and smooth flow without causing significant stagnation while performing efficient vaporization.

[0055] Figs. 7 and 8 show the case of the square heat transfer protrusions 21. When arranged evenly as shown in the figures, the flow path 22 has a uniform cross-sectional area from the inlet to Outlet and becomes serpentine. As a result, similar to the above, the heated gas G2 comes into uniform contact with the square heat transfer protrusions 21 to be heated, vaporizing the residual mist M. However, since the heated gas G2 collides with the heat transfer protrusions 21 in the second row and is deflected in the 90° direction, compared with the case of the hexagonal heat transfer protrusions 21, stagnation occurs at the center of the back surface of the heat transfer protrusions 21 in the first row and at the center of the front surface of the heat transfer protrusions 21 in the second row.

[0056] In the case of the circular heat transfer protrusions 21 in Fig. 9, the rhombic heat transfer protrusions 21 in Fig. 10, and the equilateral triangular heat transfer protrusions 21 in Fig. 11, although the flow of the heated gas G2 is not shown, in the case of the circular and equilateral triangular shapes, although the flow of the heated gas G2 is serpentine and shows high vaporization efficiency, since stagnation occurs in the flow, it is considered that the pressure loss is large. On the other hand, in the case of the rhombic shape, the flow path 22 is not serpentine and is straight, so although the pressure loss is small, the heated gas G2 passes through the flow path 22, resulting in a decrease in vaporization efficiency. From the above, the hexagonal heat transfer protrusions 21 are most preferable in terms of shape.

[0057] Next, another embodiment of the outer tube 45 will be described according to Figs. 15 to 17. As can be seen from Fig. 16, a guide protrusion 49 projects downward from the lower surface of the outlet portion 45b of the outer tube 45. This guide protrusion 49 extends parallel along the inner surfaces 15 before and after of the casing 1 that constitutes the spray space 10. And this guide protrusion 49 is provided at a position that sandwiches the inner tube tip portion 42 of the inner tube 41 from both sides.

[0058] As a result, the atomized raw material mist M blown into the spraying space 10 is blocked by this guide projection 49 and does not spread in the direction of the inner surfaces 15 at the front and rear of the casing 1, but spreads in the left - right direction of the spraying space 10. As a result, the amount of mist adhering to the inner surfaces 15 at the front and rear of the casing 1 is significantly reduced and vaporizes within the spraying space 10 maintained at a high temperature. When the amount of mist adhering to the inner surfaces 15 at the front and rear of the casing 1 decreases, the amount of products adhering and generated on the inner surface 15 during long - term use is reduced, and the maintenance of the vaporizer A can be reduced.

[0059] As can be understood from the above description, in the present invention, by making the casing 1 and the spraying space 10 plate - shaped, it is possible to provide a vaporizer capable of miniaturizing the occupied area (footprint) while maintaining a large heat transfer area compared to the size of a conventional vaporizer.

Explanation of Signs

[0060] A: Vaporizer, G0: Push gas, G1: Carrier gas, G2: Heated gas, G3: Vaporization raw material, H: Heater, L: Liquid raw material, M: Atomized raw material mist, T: Thickness of casing, t 10 ·t 20 ·t 30 : Inner dimension in the thickness direction (of the atomizing space · heat transfer promoting space · gas discharge path), W: Width of casing, w 10 : Inner dimension in the width direction of the atomizing space 1: Casing, 1a: Plate surface, 2: (One) casing component, 2a: Concave portion, 3: (The other) casing component, 3a: Convex portion, 5: Atomizer mounting hole, 6: Outlet hole, 7: Gas reservoir, 8: Carrier gas supply hole, 9: Sealing material, 10: Spray space, 10a·10b: Side surfaces, 10c: Bottom surface, 10h: Space main body portion, 10t: Ceiling portion, 15: Inner surface, 20: Heat transfer promotion space, 20a·20b: Side heat transfer promotion spaces, 20c: Bottom heat transfer promotion space, 21: Heat transfer protrusion, 22: Flow path, 28: Corner portion, 30: Vaporized raw material discharge path, 30a·30b: Side vaporized raw material discharge paths, 30c: Bottom vaporized raw material discharge path, 38: Vaporized raw material outlet, 40: Atomizer, 41: Inner tube, 41s: Tip, 42: Inner tube tip portion, 43: First flange portion, 44: Nozzle hole, 44a: Main hole portion, 44b: Supply hole, 45: Outer tube, 45a: Inner tube insertion hole, 45b: Outlet portion, 45c: Communication hole, 45s: Outer tube tip, 47: Second flange portion, 48: Jet gap, 49: Guide protrusion, 100: Liquid vaporization supply device, 110: Liquid mass flow meter, 115: Liquid raw material supply pipe, 120: Raw material tank, 130: Mass flow controller, 140: Next process (reactor)

Claims

1. A spraying space into which an atomized raw material mist obtained by atomizing a liquid raw material is supplied, a vaporized raw material discharge path that is disposed adjacent to the spraying space and discharges a vaporized raw material containing a vaporized component obtained by vaporizing the atomized raw material mist toward a next process, a heat transfer promoting space that is provided between the spraying space and the vaporized raw material discharge path so as to communicate between the two, and supplies heat to a heated gas containing the atomized raw material mist flowing from the spraying space to the vaporized raw material discharge path to vaporize the atomized raw material mist, and a casing incorporating the heat transfer promoting space, a heater for heating provided in the casing, In a vaporizer configured by an atomizer that is installed in the casing and atomizes a liquid raw material to supply the liquid raw material to the spraying space, the casing has a plate-like outer shape that is large in width with respect to the thickness, the spraying space has a plate-like shape that is large in inner dimension in the width direction with respect to the inner dimension in the thickness direction, In the heat transfer promoting space, a plurality of heat transfer protrusions configured in a polygonal shape, a circular shape, or an elliptical shape as viewed from the plate surface side of the casing, which come into contact with the flowing heated gas and vaporize the atomized raw material mist contained in the heated gas, are provided in two or more rows, and the heat transfer protrusions in the row on the vaporized raw material discharge path side are arranged in the middle of the heat transfer protrusions in the row on the spraying space side, and a flow path of the heated gas surrounding the heat transfer protrusions is formed between adjacent heat transfer protrusions. A vaporizer characterized by this.

2. An atomizer mounting hole for mounting the atomizer is provided on the upper surface of the casing, the spraying space is vertically long rectangular, and has a rectangular plate-like shape including a ceiling portion connected to the atomizer mounting hole, left and right side surfaces, and a bottom surface, The heat transfer promoting space is respectively formed along the both side surfaces and the bottom surface, and the pressure losses of the heated gas flowing through the side portion heat transfer promoting spaces along the both side surfaces and the pressure loss of the heated gas flowing through the bottom portion heat transfer promoting space along the bottom surface are set to be equal to each other. The vaporizer according to Claim 1, characterized by this.

3. When the heat transfer protrusion is polygonal, it is installed so that the corner portion faces the spraying space side, and when it is elliptical, it is installed so that the arc side with a small radius faces the spraying space side. The vaporizer according to Claim 1, characterized by this.

4. The atomizer has an inner pipe that opens into the spraying space and supplies the liquid raw material to the spraying space, It is formed by an outer tube that is arranged to surround the periphery of the inner tube and forms a jet gap for the carrier gas through which the supplied carrier gas passes and atomizes the liquid raw material between the outer surface of the inner tube. The vaporizer according to any one of claims 1 to 3, characterized in that the tip of the inner tube is provided so as to be located inside the tip of the outer tube of the outer tube. **Claim 5**: A guide protrusion extending into the spray space from the tip of the outer tube is provided at a position sandwiching the tip of the inner tube from both sides along the inner surfaces of the casing constituting the spray space that face each other. The vaporizer according to claim 4, characterized in that.

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