JP2005175249A - Apparatus and method for vaporizing liquid material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vaporizer and a vaporization method for stably and efficiently vaporizing a liquid material, such as a CVD material and an etching material without using an apparatus in a complex configuration with desired concentration and flow rate for supplying to a semiconductor manufacturing apparatus. <P>SOLUTION: The vaporizer has the supply pipe of the liquid material, a first gas supply pipe, and a second gas supply pipe. The liquid material is jetted into the first gas supply pipe and the mixture of the material, and the first gas is jetted into the second gas supply pipe. Additionally, the liquid material is jetted out to the flow of the first gas, and further the mixture of the material and the first gas is jetted out to the flow of the second gas for vaporization. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vaporizer and a vaporization method for a liquid material. More specifically, a vaporizer for efficiently vaporizing a liquid material such as a CVD material or an etching material at a desired concentration and flow rate without using a device having a complicated structure, and supplying the vaporized material to a semiconductor manufacturing apparatus; It relates to the vaporization method.

In the semiconductor field, various liquid CVD materials are used as materials for insulating films such as gate insulating films, capacitor insulating films, and interlayer insulating films, or oxide-based dielectric films for semiconductor memories. For example, tetraethoxy silicon (Si (OC ₂ H ₅ ) ₄ ) or the like is used as the CVD material for the SiO ₂ film, and trimethoxy boron (B (OCH ₃ ) ₃ ) or trimethoxy phosphorus (P) is used as the CVD material for the BPSG film. (OCH ₃ ) ₃ ) and the like are used. Further, as a CVD material for a lead zirconate titanate (PZT) film, tetraethyl lead (Pb (C ₂ H ₅ ) ₄ ), tetra tert-butoxyzirconium (Zr (OC (CH ₃ ) ₃ ) ₄ ), tetra iso -Propoxy titanium (Ti (OCH (CH ₃ ) ₂ ) ₄ ) or the like is used.

In the semiconductor field, high-purity water may be used as a CVD material or an etching material. For example, a method of forming a SiO ₂ oxide film on a substrate by a CVD method using water vapor and a silane-based gas (Japanese Patent Laid-Open No. 8-279504), or a silicon oxide using water vapor and a fluorocarbon-based gas A method of plasma etching a system material layer (Japanese Patent Laid-Open No. 8-222551) is known. In such a case, as in the case of other liquid materials, it is necessary to efficiently vaporize water at a desired concentration and flow rate and maintain it in a semiconductor manufacturing apparatus while maintaining water at an extremely high purity.

Conventionally, as a general method of vaporizing a liquid material having a relatively low boiling point, a filling container filled with the liquid material is heated and vaporized by bubbling a carrier gas from the tip of a pipe disposed in the liquid material liquid. There is a way to do it. Moreover, as a general method for vaporizing a liquid material having a relatively high boiling point, the liquid material is supplied to the vaporizer via a liquid flow rate controller such as a liquid mass flow controller, and an ejection nozzle of the vaporizer together with the carrier gas. There is a method of vaporizing by jetting from a heated vaporization chamber.
JP-A-5-263255 JP-A-6-244121 JP-A-9-181061 JP 2000-315686 A JP 2003-13234 A

However, in the vaporization method using the bubbling method, the concentration and flow rate of the material in the vaporized gas are affected by the amount of liquid material (remaining amount of liquid material) filled in the filling container or the ambient temperature. There was an easy bug. Therefore, in order to stably obtain a vaporized gas having a desired concentration and flow rate, it is necessary for a skilled engineer to control the temperature of the material and adjust the flow rate of the bubbling gas in consideration of these effects.
Further, in a vaporization method in which a liquid material is supplied in a liquid state to the vaporizer and vaporized, a vaporizer with a complicated configuration is required to obtain vaporized gas having a stable concentration and flow rate.

  Therefore, the problem to be solved by the present invention is that a liquid material such as a CVD material or an etching material can be stably and efficiently vaporized at a desired concentration and flow rate without using a device having a complicated structure. To provide a vaporizer and a vaporization method for supplying to a manufacturing apparatus.

  As a result of intensive studies to solve these problems, the inventors of the present invention have a configuration in which a liquid material is ejected into a gas flow such as a carrier gas, and the obtained mixture is again ejected into a gas flow such as a carrier gas. As a result, the vaporization efficiency is greatly improved as compared with the case where the liquid material is jetted once in the gas flow, and the vaporized gas having a desired concentration and flow rate can be stably obtained without using a complicated apparatus. As a result, the vaporizer and vaporization method of the present invention have been reached.

That is, the present invention includes a liquid material supply pipe, a first gas supply pipe, and a second gas supply pipe, and the liquid material is ejected into the first gas supply pipe. A liquid material vaporizer comprising a configuration in which a mixture of one gas is jetted into a second gas supply pipe.
According to another aspect of the present invention, there is provided a liquid material, wherein the liquid material is ejected into a first gas flow, and a mixture of the material and the first gas is ejected into a second gas flow to be vaporized. It is a vaporization method.

The present invention is applied to a vaporizer and a vaporization method for a liquid material.
The liquid material applied to the vaporizer and vaporization method of the present invention includes a gate insulating film, a capacitor insulating film, an interlayer insulating film, a CVD material used for forming an oxide-based dielectric film for a semiconductor memory, or etching. Although it is a material etc., it is not restrict | limited to these, As long as it can hold | maintain liquid state at normal temperature and a normal pressure, it will select and use suitably according to a use.

Examples of the liquid material applied to the present invention include tetraiso-propoxy titanium (Ti (OCH (CH ₃ ) ₂ ) ₄ ), tetra n-propoxy titanium (Ti (OC ₃ H ₇ ) ₄ ), tetra tert- Butoxyzirconium (Zr (OC (CH ₃ ) ₃ ) ₄ ), tetra n-butoxyzirconium (Zr (OC ₄ H ₉ ) ₄ ), tetramethoxyvanadium (V (OCH ₃ ) ₄ ), trimethoxyvanadyl oxide (VO ( OCH _{3) 3),} pentaethoxyniobium _{(Nb (OC 2 H 5)} 5), pentaethoxytantalum _{(Ta (OC 2 H 5)} 5), trimethoxy boron _{(B (OCH 3) 3)} , tri iso- propoxy aluminum _{(Al (OCH (CH 3)} 2) 3), tetraethoxysilicon _{(Si (OC 2 H 5)} 4), tetraethoxy germanium _{(Ge (OC 2 H 5)} 4), tetra Tokishisuzu _{(Sn (OCH 3) 4)} , trimethoxy phosphate _{(P (OCH 3) 3)} , trimethoxy phosphine oxide _{(PO (OCH 3) 3)} , Torietokishihi iodine _{(As (OC 2 H 5)} 3), tri A liquid alkoxide such as ethoxyantimony (Sb (OC ₂ H ₅ ) ₃ ) at room temperature and normal pressure can be used.

In addition to the above, trimethylaluminum (Al (CH ₃ ) ₃ ), dimethylaluminum hydride (Al (CH ₃ ) ₂ H), triiso-butylaluminum (Al (iso-C ₄ H ₉ ) ₃ ), hexa Fluoroacetylacetone copper vinyltrimethylsilane ((CF ₃ CO) ₂ CHCu · CH ₂ CHSi (CH ₃ ) ₃ ), hexafluoroacetylacetone copper allyltrimethylsilane ((CF ₃ CO) ₂ CHCu · CH ₂ CHCH ₂ Si (CH ₃ ) ₃ ), bis (iso-propylcyclopentadienyl) tungsten dihalide ((iso-C ₃ H ₇ C ₅ H ₅ ) ₂ WH ₂ ), tetradimethylamino zirconium (Zr (N (CH ₃ ) ₂ ) ₄ ) , Pentadimethylamino tantalum (Ta (N (CH ₃ ) ₂ ) ₅ ), pentadiethylamino tantalum (Ta (N (C ₂ H _{5 2} ) ₅ ), tetradimethylaminotitanium (Ti (N (CH ₃ ) ₂ ) ₄ ), tetradiethylaminotitanium (Ti (N (C ₂ H ₅ ) ₂ ) ₄ ), etc. Can be illustrated. In the present invention, water can also be used as the liquid material.

Hereinafter, although the vaporizer | carburetor and vaporization method of this invention are demonstrated in detail based on FIGS. 1-4, this invention is not limited by these.
1 to 3 are cross-sectional views showing examples of the vaporizer of the present invention, and FIG. 4 is a configuration diagram showing an example of a vaporization supply apparatus to which the vaporization method of the present invention can be applied.
As shown in FIG. 1, the vaporizer of the present invention has a liquid material supply pipe 1, a first gas supply pipe 2, and a second gas supply pipe 3, and the liquid material is a first gas. And a mixture of the material and the first gas is jetted into the second gas supply pipe.

  The material of each supply pipe used in the vaporizer of the present invention is usually stainless steel, and the outer shape is usually a cylindrical shape or a shape similar thereto, but is not limited thereto, for example, The diameter of the second gas supply pipe may be larger than that of the other portion at the outlet of the mixture of the material and the first gas (for example, a spiral channel 5 is provided as shown in FIG. 2). Case).

  The supply pipe of the liquid material has a structure in which the supply pipe itself is thin, the tip is thin, the tip ejects liquid material from a plurality of pores, or the flow rate is limited by other means. Yes. In any case, the inner diameter of the state-of-the-art tube, the diameter of the pore, or the gap when the gap or the like is converted into a circular hole is usually 1.0 mm or less, preferably 0.3 mm or less. Also, the first gas supply pipe has a narrow tip, a structure in which the tip ejects liquid material from a plurality of pores, or a structure in which the flow rate is limited by means other than these. In any case, the inner diameter of the state-of-the-art tube, the diameter of the pore, or the gap when the gap or the like is converted into a circular hole is usually ½ or less of the inner diameter of the supply pipe other than the tip, preferably 1/4 or less.

  In the vaporizer of the present invention, as shown in FIG. 2, downstream of the position where the second gas is mixed (position where the mixture of the material and the first gas is in contact with the second gas), It is preferable to provide a spiral channel 5. By adopting such a configuration, for example, even when a liquid material having a relatively high boiling point is ejected twice with respect to the gas flow, a part of the material remains in an atomized state without being completely vaporized. Since the heater is efficiently heated, the atomized liquid material can be easily vaporized. Furthermore, for the same reason, as shown in FIG. 3A, a spiral flow path can be provided on the downstream side from the mixing position of the material and the first gas. The spiral channel is particularly effective in the case of normal pressure vaporization or vaporization near normal pressure (50 to 150 kPa).

  The vaporizer shown in FIGS. 1 and 2 has a structure in which a liquid material supply pipe and a first gas supply pipe are introduced from a direction perpendicular to the second gas supply pipe. The vessel is not limited to this, and for example, a structure as shown in FIGS. 3 (2) to (4) or a structure similar to these structures may be used. The vaporizer of the present invention has a structure as shown in FIG. 3 (5) or a liquid material supply pipe 3 in the vaporizer of FIG. 3 (5) in order to vaporize two or more kinds of liquid materials at the same time. A structure including two or more structures that are increased to more than one, and a structure in which the liquid material is ejected into the first gas supply pipe (a structure including a liquid material supply pipe and a first gas supply pipe). It is also possible.

The vaporizer of the present invention is usually provided with a heater 4 on the side surface of the gas supply pipe. The type and form of the heater are not particularly limited, but for example, a cylindrical electric heater can be used. In the present invention, a heater can also be provided on the side surface of the liquid material supply pipe as required.
1 to 3 are horizontal carburetors, but in the present invention, these carburetors may be arranged vertically and used in either upflow or downflow systems. it can.

The vaporization method of the present invention is a method for vaporizing a liquid material using the vaporizer. That is, the liquid material is jetted into the first gas flow, and the mixture of the material and the first gas is jetted into the second gas flow to be vaporized.
In the vaporization method of the present invention, a carrier gas such as hydrogen, helium, nitrogen, or argon is usually used as the first gas. In addition to the carrier gas, a gas containing an etching gas may be used as the second gas.

  As an example of using a gas containing an etching gas as the second gas, for example, water is used as the liquid material, fluorocarbon is used as the etching gas, water is vaporized into water vapor, and water vapor and fluorocarbon are mixed to oxidize. The case where it uses for the plasma etching of a silicon-type material layer can be mentioned. The carrier gas used as the first gas and the carrier gas used as the second gas or the base gas of the second gas are usually the same type of carrier gas.

  When the liquid material is vaporized and supplied to the semiconductor manufacturing apparatus using the vaporization method of the present invention, the vaporizer of the present invention includes a carrier gas supply line 6, a liquid material container 8, a degassing as shown in FIG. 4, for example. It is connected in advance to a vessel 9, a liquid mass flow controller 10, a carrier gas or etching gas supply line 11, a preheater 14, a semiconductor manufacturing apparatus 15, and the like. Moreover, the heat insulating material 13 is installed around the vaporizer 12 as needed. Thereafter, the liquid material 7 is supplied to the vaporizer 12 via the degasser 9 and the liquid mass flow controller 10 due to the pressure of the gas from the carrier gas supply line 6, vaporized, and supplied to the semiconductor manufacturing apparatus 15. The

  In the vaporization method of the present invention, two or more kinds of liquid materials are filled in the same liquid material container under the condition that they do not react with each other and do not adversely affect each other. Or it is also possible to vaporize with the vaporizer of a structure as shown to FIG. 3 (1)-(4). It is also possible to fill two or more types of liquid materials into separate liquid material containers and vaporize them with a vaporizer having a structure as shown in FIG.

  The vaporizer of the present invention comprises a liquid material supply pipe, a first gas supply pipe, and a second gas supply pipe, and has a simple configuration. Moreover, the vaporization method of the present invention is excellent in vaporization efficiency because the liquid material is jetted twice into the gas flow using the vaporizer. Therefore, according to the vaporizer and vaporization method of the present invention, the liquid material can be stably and efficiently vaporized at a desired concentration and flow rate and supplied to the semiconductor manufacturing apparatus without using a complicated apparatus. It has become possible.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

(Production of vaporizer)
It has a liquid material supply tube (narrow tube) with an inner diameter of 0.25 mm, a first gas supply tube with an inner diameter of 1.6 mm (inner diameter at the tip: 0.4 mm), and a second gas supply tube with an inner diameter of 16 mm. Then, a vaporizer as shown in FIG. 2 provided with a spiral channel was manufactured. The length of the second gas supply pipe is 225 mm, the length of the spiral flow path is 150 mm, the length of the liquid material supply pipe in the second gas supply pipe is 15 mm, and the length of the first gas The length of the supply pipe was 25 mm. The position at which the liquid material and the first gas were introduced into the second gas supply pipe was set to 45 mm from the left end of the second gas supply pipe. Further, a cylindrical electric heater was provided on the entire side surface of the second gas supply pipe.

(Production of vaporization supply device)
The vaporizer manufactured as described above is connected to a carrier gas supply line, a liquid material container filled with tetraethoxysilicon, a degasser, a gas mass flow controller, a carrier gas or etching gas supply line, etc., as shown in FIG. The vaporization supply device was manufactured. In addition, a concentration monitor capable of continuously measuring the concentration of the liquid material in the vaporized gas was installed at the outlet of the vaporizer.

(Vaporization test)
The inner wall temperature of the second gas supply pipe (the position where the material and the first gas are in contact) is heated to 190 ° C., and tetraethoxy silicon as the liquid material is 0.2 g / min. As a second gas, nitrogen was supplied to the vaporizer at a flow rate of 500 ml / min to vaporize tetraethoxy silicon. The concentration of tetraethoxysilicon in the vaporized gas was measured at intervals of 10 seconds at the outlet of the vaporizer for 120 minutes after the inner wall temperature of the second gas supply pipe became constant. As a result, the concentration of tetraethoxysilicon was almost constant from the start to the end of concentration measurement. Further, Table 1 shows the vaporization rate of tetraethoxy silicon and the maximum variation rate of concentration ((maximum concentration−minimum concentration) / average concentration).

(Example 2)
(Production of vaporizer)
It has a liquid material supply tube (narrow tube) with an inner diameter of 0.25 mm, a first gas supply tube with an inner diameter of 1.6 mm (inner diameter at the tip: 0.4 mm), and a second gas supply tube with an inner diameter of 16 mm. Then, a vaporizer as shown in FIG. 3 (2) provided with a spiral channel was manufactured. The length of the second gas supply pipe is 225 mm, the length of the spiral flow path is 150 mm, the length of the liquid material supply pipe in the second gas supply pipe is 60 mm, and the length of the first gas The length of the supply pipe was 70 mm. Further, a cylindrical electric heater was provided on the entire side surface of the second gas supply pipe.

(Vaporization test)
A vaporization supply apparatus was produced in the same manner as in Example 1 except that the vaporizer produced as described above was used, and a vaporization test was performed as follows.
The inner wall temperature of the second gas supply pipe is heated to 160 ° C., trimethoxyboron is 0.2 g / min as the liquid material, nitrogen is 50 ml / min as the first gas, and the second gas is used as the second gas. Nitrogen was supplied to the vaporizer at a flow rate of 350 ml / min to vaporize trimethoxyboron. The concentration of trimethoxyboron in the vaporized gas was measured at intervals of 10 seconds at the outlet of the vaporizer for 120 minutes after the inner wall temperature of the second gas supply pipe became constant. As a result, the concentration of trimethoxyboron was almost constant from the start to the end of concentration measurement. The vaporization rate of trimethoxyboron and the maximum variation rate of concentration ((maximum concentration−minimum concentration) / average concentration) are shown in Table 1.

(Example 3)
In the vaporization test of Example 1, water was vaporized in the same manner as in Example 1 except that water was used as the liquid material and CF ₄ was used as the second gas. However, the inner wall temperature of the second gas supply pipe was set to 140 ° C., and water was supplied to the vaporizer at a flow rate of 0.5 g / min, nitrogen was 500 ml / min, and CF ₄ was 1000 ml / min. As a result, the concentration of water was almost constant from the start to the end of concentration measurement. Further, Table 1 shows the vaporization rate of water and the maximum variation rate of concentration ((maximum concentration−minimum concentration) / average concentration).

(Comparative Example 1)
In the manufacture of the vaporizer of Example 1, the vaporizer was manufactured in the same manner as in Example 1 except that the first gas supply pipe was not used, and the same procedure as in Example 1 was performed except that this vaporizer was used. A vaporization supply device was manufactured.
While heating so that the inner wall temperature of the supply pipe becomes 190 ° C., tetraethoxy silicon as a liquid material is supplied to the vaporizer at a flow rate of 0.2 g / min and nitrogen at a flow rate of 600 ml / min to vaporize tetraethoxy silicon. I did it. The concentration of tetraethoxysilicon in the vaporized gas was measured at intervals of 10 seconds at the outlet of the vaporizer for 120 minutes after the inner wall temperature of the supply pipe became constant. As a result, the concentration of tetraethoxysilicon was almost constant from the start to the end of concentration measurement. Further, Table 1 shows the vaporization rate of tetraethoxy silicon and the maximum variation rate of concentration ((maximum concentration−minimum concentration) / average concentration).

  As described above, it was confirmed that the example of the present invention can efficiently vaporize and supply the liquid material at a constant concentration and flow rate.

Sectional drawing which shows an example of the vaporizer | carburetor of this invention Sectional drawing which shows an example of vaporizers other than FIG. 1 of this invention. Sectional drawing which shows the example of vaporizers other than FIG. 1, FIG. 2 of this invention The block diagram which shows an example of the vaporization supply apparatus which can apply the vaporization method of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid material supply pipe 2 1st gas supply pipe 3 2nd gas supply pipe 4 Heater 5 Spiral flow path 6 Carrier gas supply line 7 Liquid material 8 Liquid material container 9 Degasser 10 Liquid mass flow controller DESCRIPTION OF SYMBOLS 11 Carrier gas or etching gas supply line 12 Vaporizer 13 Heat insulating material 14 Preheater 15 Semiconductor manufacturing apparatus

Claims (9)

  A liquid material supply pipe, a first gas supply pipe, and a second gas supply pipe, wherein the liquid material is jetted into the first gas supply pipe, and the mixture of the material and the first gas A vaporizer for a liquid material, characterized in that the liquid is vaporized into the second gas supply pipe.   The vaporizer of the liquid material of Claim 1 which provided the helical flow path in the downstream from the position where 2nd gas is mixed.   2. The liquid material vaporizer according to claim 1, wherein the first gas supply pipe and the second gas supply pipe are supply pipes for supplying the same type of carrier gas.   2. The liquid material vaporizer according to claim 1, wherein the first gas supply pipe is a supply pipe for supplying a carrier gas, and the second gas supply pipe is a supply pipe for supplying an etching gas.   2. The liquid material vaporizer according to claim 1, wherein a heater is provided on a side surface of the first gas supply pipe and / or the second gas supply pipe.   A method of vaporizing a liquid material, characterized in that the liquid material is jetted into a first gas flow, and the mixture of the material and the first gas is jetted into a second gas flow to vaporize.   The liquid material vaporization method according to claim 6, wherein the liquid material is a CVD material or an etching material.   The liquid material vaporization method according to claim 6, wherein the first gas and the second gas are the same type of carrier gas. The method for vaporizing a liquid material according to claim 6, wherein the first gas is a carrier gas and the second gas is a gas containing an etching gas.

Images