JP3164662B2 - Material gas supply pipe heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for a supply pipe for supplying a material gas to a reactor used, for example, in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In recent years, as a material for forming a thin film by vapor phase growth, a liquid material gas having a low vapor pressure has begun to be used in addition to a conventional gas having a high vapor pressure. This is because a thin film having excellent uniformity and coatability can be obtained at a relatively low temperature and is suitable for a fine process. FIG. 4 shows an example of a reduced pressure vapor phase growth apparatus using a liquid material.

[0003] Liquid material vaporizer (hereinafter, vaporizer)
A tank 41 is housed inside the tank 40, and a liquid material 42 is housed inside the tank 41. A heater 43 is provided on the inner surface of the vaporizer 40, and the inside of the vaporizer 40 is maintained at a temperature suitable for vaporizing the liquid material 42 by the heater 43.

[0004] One end of a gas supply pipe (hereinafter simply referred to as a pipe) 44 is connected to the tank 41, and the other end of the pipe 44 is connected to a reaction furnace 45. The pipe 44 located inside the vaporizer 40 has a valve 4
6 and a mass flow controller 47 for controlling the flow rate of the gas are provided. The material gas vaporized in the tank 41 is supplied to the valve 46 and the mass flow controller 4.
7. It is supplied to a reaction furnace 45 via a pipe 44. A plasma discharge mechanism (not shown), a substrate to be processed, and the like are provided inside the reaction furnace 45.
A heater 48 is provided for heating the gas in the chamber to a predetermined temperature. Further, an exhaust port 49 for discharging gas is provided at an upper portion of the reaction furnace 45.

Incidentally, the material gas once vaporized should not be reliquefied in order to prevent the generation of solid matter in the pipe 44 and the generation of dust due to the gas phase decomposition of the material gas. is important. For this reason, it is necessary to maintain the temperature of the pipe 44 for guiding the material gas from the tank 41 to the reaction furnace 45 higher than the inside of the vaporizer 40 by the heating means. As the heating means, a tape heater is generally used.

FIGS. 5A and 5B show a state in which a tape heater 51 is wound around a pipe 44. In order to improve heating efficiency, the outside of the tape heater 51 is made of a heat insulating material 5.
2 is covered.

[0007]

However, the pipe 4 for connecting the reaction furnace 45 to the tank 41 in the vaporizer 40 is required.
4 is often complicated, and the pipe 44 has many curved portions. The tape heater 5
In the case of winding 1, the tape heaters overlap as shown in FIG. 6A, or a gap is formed between the tape heaters as shown in FIG. 6B. As shown in FIG. 2A, when the tape heaters are welded, it takes time to rewind the tape heater when performing maintenance of the piping. In addition, as shown in FIG. 3B, when a gap occurs between the tape heaters, the temperature distribution of the pipe becomes non-uniform, and a low-temperature portion occurs locally. in this way,
When a low-temperature part is generated in the pipe, the material gas supplied into the pipe is trapped in the low-temperature part, and the time until the gas reaches the reaction furnace 45 is delayed, or the substantial flow rate supplied to the reaction furnace 45, that is, This causes problems such as a decrease in the effective flow rate and an insufficient supply amount to the substrate to be processed.

The pipe 44 is provided with a plurality of valves (not shown), and these valves also need to be heated. However, when this valve is heated by a tape heater,
The same problem as above occurs. Further, not only when the reactor 45 and the vaporizer 40 are connected by a single pipe but also when a plurality of pipes are used, the above problem becomes more serious.

That is, recently, in a semiconductor process, a doping source in which a liquid material such as TEOS, P, B, or As is combined is used as a solid-phase diffusion source or a reflow material. As described above, in the apparatus using a plurality of material gases, the plurality of material gases are supplied to the reaction furnace through individual pipes. For this reason, when the effective flow rate of each material gas supplied by each pipe decreases, the concentration distribution of the doping source in the film formed on the substrate to be processed becomes non-uniform. Therefore, when a semiconductor device is manufactured using this substrate, various troubles are expected to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to introduce a material gas to a reaction furnace in a vapor phase growth apparatus using a liquid material gas having a low vapor pressure. An object of the present invention is to provide a heating device for a material gas supply pipe that can uniformly heat a supply pipe, prevent a decrease in an effective flow rate to a reaction furnace, and that is easy to maintain.

[0011]

SUMMARY OF THE INVENTION This invention is to solve the above problems, a supply pipe leading from the liquid material vaporizing means for vaporizing the material gas material gas into the reaction furnace, the feed
It has a tunnel for accommodating pipes, and is installed inside the tunnel.
The liquid material is introduced into the tunnel by the heated heating means.
Inactive supplied from the vaporization means side and discharged from the reactor side
Thermostat that heats the supply pipe by heating the reactive gas
Is provided.

Furthermore, the constant temperature apparatus has the liquid material vaporizer side supply port for supplying the inert gas into the tunnel in the tunnel, preparative <br/> tunnel to the reactor side of the tunnel have the inert gas within a discharge port for discharging
You.

[0013]

That is, according to the present invention, a supply pipe for guiding a material gas from a liquid material vaporizing means to a reaction furnace is arranged in a constant temperature apparatus,
By heating means provided in the thermostat,
The supply pipe is heated by heating the inert gas.
You. Therefore, the entire supply pipe can be uniformly heated without being affected by the bent portion and the valve of the supply pipe, and the material gas in the supply pipe can be prevented from being reliquefied.

Further, since the tape heater is not directly wound around the supply pipe, but is merely provided in the inert gas to be heated, piping work and maintenance in case of trouble are easy. is there.

Further, when an inert gas is supplied from the liquid material vaporization means side to the reaction furnace side into the tunnel provided with the supply pipe, the inert gas is heated to a temperature higher on the reaction furnace side than on the liquid material vaporization means side. It has a gradient, and the temperature distribution of the supply pipe is the same. For this reason, the reliquefaction of the material gas in the supply pipe can be further prevented.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In FIG. 1, inside the vaporizer 10,
A tank 11 is accommodated, and a liquid material 12 is accommodated inside the tank 11. A heater 13 is provided on the inner surface of the vaporizer 10, and the inside of the vaporizer 10 is maintained at the temperature of the liquid material 12 by the heater 13.

One end of a gas supply pipe (hereinafter simply referred to as a pipe) 14 is connected to the tank 11, and the other end of the pipe 14 is connected to a reaction furnace 15. The pipe 14 located inside the vaporizer 10 has a valve 1
6 and a mass flow controller 17 for controlling the gas flow rate. A control valve 18 is provided on the pipe 14 located in front of the reaction furnace 15. The material gas vaporized in the tank 11 is supplied to the valve 16, the mass flow controller 17, and the pipe 1.
4. It is supplied to the reaction furnace 15 via the control valve 18. A plasma discharge mechanism (not shown), a non-processed substrate, and the like are provided inside the reaction furnace 15.
9 are provided. Further, an exhaust port 20 for discharging gas is provided at an upper portion of the reaction furnace 15.

On the other hand, the tank 11 of the vaporizer 10
14 and control valve 1 connecting the reactor and the reactor 15
Reference numeral 8 is provided in a tunnel 22 constituting the thermostat 21. A supply port 23 for supplying, for example, an inert gas to the inside of the tunnel 22 is provided at an end of the constant temperature device 21 on the side of the vaporizer 10, and a supply port 23 for supplying the inert gas to the inside of the tunnel 22 is provided at an end of the reaction furnace 15. An exhaust port 24 for exhausting the inert gas and the material gas leaked from the pipe 14 is provided. Further, a door 25 that is opened and closed for maintenance of the control valve 18 and the like is provided near the control valve 18 of the thermostat 21.

FIG. 2 shows the internal configuration of the thermostat 21. A heating member 27 such as an electric heater is provided on the inner surface of the tunnel 22 constituting the constant temperature device 21 with a heat insulating material 26 interposed therebetween. The inert gas in the tunnel 22 is heated by the heating member 27 and
The control valve 18 is heated by the heated inert gas.

According to the above embodiment, since the pipe 14 and the control valve 18 are disposed in the constant temperature space provided inside the constant temperature device 21, the pipe 14 and the control valve 18 include the bent portion of the pipe and the control valve 18. The entire pipe 14 can be heated uniformly. Therefore, reliquefaction of the material gas in the pipe 14 can be prevented, and a delay in the arrival time from the tank 11 to the reactor 15 and a shortage of the material gas supply due to a decrease in the effective flow rate can be solved.

The inert gas supplied from the supply port 23 into the tunnel 22 is discharged from the exhaust port 24 while being heated. Therefore, the temperature gradient of the inert gas in the tunnel 22 is set so that the temperature gradually increases from the supply port 23 to the exhaust port 24, so that the material gas in the pipe 14 also reacts from the tank 10 side. Since it is gradually heated as it is guided to the furnace 15, it is more difficult to liquefy.

Further, since the pipe work is completed only by inserting the pipe into the tunnel 22 of the constant temperature device 21 without using a tape heater as in the related art, the work efficiency can be improved. In addition, when a valve or the like provided in the middle of the pipe breaks down and it is necessary to replace the valve or the like, it is not necessary to remove the tape heater as in the related art, so that the maintenance work efficiency can be dramatically improved. .

FIG. 3 shows a second embodiment of the present invention and shows a case of a semiconductor process using a plurality of material gases. The same parts as those in FIG. 1 are denoted by the same reference numerals and only different parts will be described.

In FIG. 3, vaporizers 10a, 10a
Tanks 11a and 11b are accommodated inside b, respectively, and liquid materials 12a and 12b are accommodated inside these tanks 11a and 11b, respectively. The liquid material 12a is, for example, TEOS, and the liquid material 12b is, for example, P, B, As, or the like.

On the other hand, pipes 14a and 14b connecting the tanks 11a and 11b of the vaporizers 10a and 10b and the reaction furnace 15 and control valves 18a and 18b are
It is arranged in a tunnel 22 constituting the constant temperature device 21.

According to the above configuration, each of the pipes 14a, 14a
b and the control valves 18a, 18b
The pipes 14a and 14b and the control valves 18a and 18b
Can be uniformly heated. Therefore, the reliquefaction of the material gas in each of the pipes 14a and 14b can be prevented, and the delay of the arrival time to the reactor and the shortage of the material gas supply due to the decrease of the effective flow rate can be solved.

Further, the pipe work is completed only by arranging the pipes 14a and 14b in the tunnel 22 of the thermostat 21, so that the work efficiency can be improved. Therefore, according to this configuration, the greater the number of pipes, the more remarkable the improvement in work efficiency.

It should be noted that the present invention is not limited to the above-described embodiment, but is relatively easy to liquefy like TEOS and the like, and is also applicable to piping systems such as dichlorosilane and ammonia gas used as a material gas for a silicon nitride film. Applicable. In addition, the constant temperature device 21 can be used as a degassing device by extracting gas from the supply pipe itself by increasing the heating efficiency. Of course, various modifications can be made without departing from the scope of the present invention.

[0030]

As described above in detail, according to the present invention, in a vapor phase growth apparatus using a liquid material gas having a low vapor pressure, a pipe for guiding a material gas to a reaction furnace can be uniformly heated. In addition, it is possible to provide a heating device for the material gas supply pipe, which can prevent a decrease in the effective flow rate to the reaction furnace and can be easily maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing an essential part of FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing an example of a conventional heating device.

5A and 5B show a configuration of a tape heater used in the apparatus shown in FIG. 4; FIG. 5A is a side view showing a main part taken out, and FIG. 5B is a side view of FIG. Sectional drawing along the bb line.

FIG. 6 is a side view showing a configuration of the tape heater, in which main parts are taken out and shown.

[Explanation of symbols]

10, 10a, 10b ... vaporizer, 11, 11a,
11b: tank, 12, 12a, 12b: liquid material, 1
4, 14a, 14b: pipe, 15: reactor, 18, 1
8a, 18b: control valve, 21: constant temperature device, 22:
Tunnel, 27: heating member.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-283371 (JP, A) JP-A-5-85890 (JP, A) JP-A-56-158420 (JP, A) JP-A-2- 190473 (JP, A) JP-A-63-278228 (JP, A) JP-A-2-210822 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/205 H01L 21 / 31 H01L 21/302 C23C 16/00 C30B 25/00

Claims (2)

(57) [Claims] 1. A supply pipe for guiding a material gas from a liquid material vaporizing means for vaporizing a material gas to a reaction furnace, and a tunnel accommodating the supply pipe.
By the heating means provided on the inner surface,
The liquid material is supplied from the vaporizer and discharged from the reactor.
Heating the supply pipe by heating the inert gas
A heating device for a material gas supply pipe, comprising: a constant temperature device . Wherein said thermostat, the have the liquid material vaporizer side supply port for supplying the inert gas into the tunnel in the tunnel, the non in tunnels on the reactor side of the tunnel The heating device for a material gas supply pipe according to claim 1, further comprising an outlet for discharging the active gas.