JP2003213434A - Liquid material vaporizing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid material vaporizing apparatus in which the generation of non-vaporized residues and thermal-decomposition residues is reduced, and the vaporizing efficiency is improved. <P>SOLUTION: A nozzle 1 to atomize and spray a liquid material is fixed to a vaporizing chamber 2 so as to spray the liquid material in the horizontal direction, the liquid material is scattered by the scattering force in the horizontal direction corresponding to the particle size of the sprayed liquid material, and the gravity corresponding to the mass, the heating temperature of a bottom part (areas 22a, 22b and 22c) of the vaporizing chamber 2 is changed step by step corresponding to the distance from the nozzle 1, and the thermal energy optimum to the liquid particles is supplied to reduce the non-vaporized residues and the thermal-decomposition residues, and to improve the vaporizing efficiency. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MOC using a liquid material in semiconductor device manufacturing, superconducting material manufacturing and the like.
VD (Metal Organic Chemical)
The present invention relates to a liquid material vaporizer used in a film forming process by a Vapor Deposition method.

[0002]

2. Description of the Related Art In the semiconductor device manufacturing process, MOCV
Since the film formation by the D method is more advantageous than the film formation by sputtering etc. in terms of film quality, film formation speed and step coverage, it is widely used. CVD required for this
As a gas supply method, a method in which a liquid organic metal or a liquid material in which an organic metal is dissolved in a solvent is sprayed through a nozzle into a liquid material vaporizer that maintains a constant temperature and vaporized immediately before a CVD reactor is controllable and stable. In terms of sex, it is attracting attention because it is superior to the bubbling method and the sublimation method. As the liquid material, a material in which an organic metal is liquid at room temperature, or a solid (for example, a high dielectric constant material BST such as Sr (dpm) ₂ ) dissolved in an organic solvent (for example, tetrahydrofuran THF) is used. ing.

[0003]

The conventional liquid material vaporizer is constructed as described above. However, when vaporizing a liquid material, the conventional liquid material vaporizer uses particles of different sizes with the same thermal energy. Since it is vaporized, sufficient thermal energy cannot be given to particles that have a large heat capacity in proportion to the size, so unvaporized residue or thermal decomposition residue is generated and vaporization efficiency is reduced, and the supply amount is also increased. There is a problem that it cannot be increased. Also, when liquid materials are mixed and vaporized,
Due to different vapor pressure and thermal decomposition temperature characteristics, some components are generated inside the vaporizer as unvaporized or thermal decomposition residues, and the temperature drops at the vaporized part even when individual vaporizers are prepared. Then, there is a problem that unvaporized or thermally decomposed residues are generated inside the vaporizer, and the structure of the vaporizer becomes large. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid material vaporizer that reduces the residue generated inside the vaporizer and improves vaporization efficiency.

[0004]

In order to achieve the above object, the liquid material vaporization apparatus of the present invention has a method in which a liquid material is ejected from a nozzle into an atomized state and then collided with the inner wall of a heated vaporization chamber. In the liquid material vaporizer for vaporizing the liquid material, the nozzle is arranged in the vaporizing chamber so that the spraying direction of the atomized liquid material from the nozzle is horizontal,
It is characterized in that the temperature of the inner wall of the vaporization chamber can be changed stepwise according to the distance from the nozzle. Furthermore, in the liquid material vaporizer configured as described above, a temperature monitor for measuring the temperature of the bottom inner wall is provided at the upper part of the vaporization chamber.
The liquid material vaporizer of the present invention is configured as described above, and achieves high vaporization efficiency by spraying the liquid material in the horizontal direction and changing the temperature stepwise according to the location in the vaporization chamber. You can

[0005]

1 to 3 are views for explaining an embodiment of a liquid material vaporizer according to the present invention, FIG. 1 is a side view of the liquid material vaporizer, and FIG. 2 is a diagram. 1 is an enlarged view of B portion, and FIG. 3 is a sectional view taken along line AA ′ of FIG. As shown in FIG. 1, a liquid material vaporizer basically includes a nozzle 1 for inhaling a liquid material and a spray gas to atomize the liquid material.
And a vaporization chamber 2 for supplying thermal energy to the liquid material atomized by the nozzle 1 to deliver the vaporized gas converted.

Liquid material is supplied to the nozzle 1 from the transfer line 1a, and spray gas is supplied to the spray gas line 1b. This nozzle 1 is shown in FIG. 2 (enlarged view of portion B in FIG. 1)
As shown in, the pipe through which the liquid material and the spray gas flow has a double pipe structure composed of the inner pipe 11 and the outer pipe 12, and the liquid material flows inside the inner pipe 11 and the inner pipe 11 and the outer pipe 12. The atomizing gas flows in an annular space between the pipe 12 and the pipe 12. An orifice member 13 is provided at the tip of the nozzle 1. Further, the nozzle 1 is provided with a water cooling jacket 15 at an upper end portion of a casing 14, and a cooling rod 16 extending downward from the water cooling jacket 15 is composed of the inner pipe 11 and the outer pipe 12.
A heavy pipe is provided. The above-mentioned orifice member 13 is formed of a resin or the like having a low heat conductivity, is sandwiched between the tip portion of the outer pipe 12 and the tip portion of the casing 14, and also functions as a heat insulating member between the two.

In the vaporization chamber 2, a front block 21 into which the nozzle 1 is inserted and fixed, a hollow body portion 22 forming a main vaporization region, and a rear block 23 provided with a vaporized gas outlet 23a are bolted to a bolt 24. Are combined by. The hollow body portion 22 has a rectangular spatial cross section as shown in FIG. 3, and the bottom portion has three areas 22a, 22b,
It is divided into 22c. In the area 22a closest to the nozzle 1, a heater H1 for supplying thermal energy for vaporizing the atomized liquid material and a temperature sensor S1 for measuring the heating temperature are inserted.
Similarly, the heater H2 and the temperature sensor S are provided in the area 22b.
2 is inserted, and the heater H3 and the temperature sensor S3 are inserted in the area 22c farthest from the nozzle 1. Further, the heater H4 is provided on the upper side portion 22d of the hollow body portion 22.
And the temperature sensor S4 are inserted, and the heater H5 and the temperature sensor S5 are inserted in the right side surface portion 22e.
A heater H6 and a temperature sensor S6 are inserted in the.
Further, a heater H7 and a temperature sensor S7 are inserted in the front block 21, and a heater H8 and a temperature sensor S8 are inserted in the rear block 23. And
These heaters H1 to H8 are individually controlled by the temperature control device 3 to reach the required temperatures.

The liquid material ejected from the nozzle 1 is
The shearing force of the atomizing gas forms droplets of fine particles to be sprayed, but the particle diameters of these droplets are not uniform and necessarily have a constant distribution characteristic. FIG. 4 schematically shows the process of scattering particles of the liquid material sprayed from the nozzle 1. Here, in order to explain the operation of the particles in a simple manner, the size of the particles is divided into three, and the particles are distinguished as particles R1, particles R2, and particles R3 in descending order.

Since the particle R1 is a droplet having a large particle size and naturally has a large mass, the particle R1 concentrates and flies on the area R22a closest to the nozzle 1, and the particle R2 concentrates on the area 22b because it is smaller than the particle R1 and has a smaller mass. Come flying. Since the particle R3 has the smallest particle size and the smallest mass, the nozzle 1
Focus on the farthest area 22c and fly. In general, a droplet having a large particle size naturally has a large mass and a large amount of thermal energy for vaporization.
2. The thermal energy required to vaporize the particles R3 decreases in that order.

In order to generate the above thermal energy, the heating temperature T1 of the area 22a of the main vaporization chamber 2 is set to the highest temperature for heating the heaviest particle R1. The heating temperature T3 of the area 22c is set to a low temperature in order to heat the lightest particle R3. The heating temperature T2 of the area 22b is T1> T2.
It is set to a predetermined temperature of> T3. Further, the heating temperature of the upper side portion 22d, the right side surface portion 22e, the left side surface portion 22f, the front side block 21, the rear side block 23, etc. is controlled so that the vaporized gas is not recondensed.

As a result, the particles R1, R2, and R3 are heated at the temperatures T1, 2, and 3 required respectively, and absorb heat energy to be vaporized, so that unvaporized residue and thermal decomposition residue are reduced. The vaporization efficiency is improved. Also,
As a result, the unvaporized residue and the thermal decomposition residue are removed, so that the heating temperature can be lowered to decompose and remove the residue.

In particular, when vaporizing a liquid material having a low vapor pressure and a vaporization temperature and a decomposition temperature which are close to each other, the temperature (T
1 to T3) even when the temperature is high, by setting the heating temperature of other parts to a lower temperature below the decomposition temperature,
It is possible to prevent adhesion to the wall surface of the vaporization chamber due to decomposition.

FIG. 5 shows another embodiment of the vaporizer of the present invention. This vaporizer is the same as the vaporizer of the embodiment shown in FIG.
22d on the vaporization surface on the area 22a where
Infrared sensor 4 is provided as a temperature sensor. The infrared sensor 4 monitors the area 22a to which the non-vaporized residue is most likely to adhere, and the non-vaporized residue is accumulated or the atomization of the liquid material does not normally operate due to the blowing failure of the nozzle 1 or the like, and the area 22a is detected. When the surface temperature of (1) does not reach a predetermined temperature, an alarm signal notifying that maintenance is required is transmitted. When using such an infrared sensor 4, the infrared sensor 4
It is necessary to allow a purge gas to flow around the introduction port 4a to prevent the vaporized gas from adhering to the introduction port 4a.

As described above, in the vaporizer of the present invention, the liquid material is sprayed in the horizontal direction to disperse the particles in accordance with the mass of the liquid material, and the thermal energy corresponding to the size of the particle group can be supplied. However, the shape of the vaporizer, the insertion location of the heater and the temperature sensor, the number of the vaporization apparatus, and the like are not limited to the present embodiment.

[0015]

INDUSTRIAL APPLICABILITY The liquid material vaporizer of the present invention absorbs thermal energy corresponding to the particle diameter of the sprayed liquid material and is vaporized, so that unvaporized residue and thermal decomposition residue are reduced, and residue Even if occurs, the vaporized gas can be stably supplied because it is prevented from scattering to the vaporized gas outlet.

[Brief description of drawings]

FIG. 1 is a side view of a liquid material vaporizer according to an embodiment of the present invention.

FIG. 2 is an enlarged view of part B in FIG.

FIG. 3 is a sectional view taken along the line AA ′ in FIG.

FIG. 4 is a schematic diagram of scattering of particles of a spray liquid material.

FIG. 5 is a side view of a liquid material vaporizer according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Nozzle 1a ... Transfer line 1b ... Spray gas line 2 ... Vaporization chamber 3 Temperature controller 4 ... Infrared sensor 4a ... Introduction port 11 ... Inner piping 12 ... Outside piping 13 ... Orifice member 14 ... Casing 15 ... Water cooling jacket 16 ... Cooling rod 21 ... Front block 22 ... Hollow body 22a, 22b, 22c ... area 22d ... upper side 22e ... Right side view 22f ... Left side view 23 ... Rear block 23a ... vaporized gas outlet 24 ... bolt H1 to H8 ... Heater R1, R2, R3 ... particles S1 to S8 ... Temperature sensor

Claims (2)

[Claims] 1. A liquid material vaporizer in which a liquid material is ejected from a nozzle into an atomized state and then collided with the inner wall of a heated vaporization chamber to vaporize the liquid material from the nozzle into the vaporization chamber. The vaporization of a liquid material characterized in that the nozzle is arranged in the vaporization chamber so that the ejection direction of the liquid material is horizontal, and the temperature of the inner wall of the vaporization chamber can be changed stepwise according to the distance from the nozzle. apparatus. 2. The liquid material vaporizer according to claim 1, wherein a temperature monitor for measuring the temperature of the bottom inner wall is provided on the upper portion of the vaporization chamber.