JPH055941Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to liquid or solid raw materials (e.g.
This invention relates to a raw material vaporization and supply control device for precisely and stably controlling the vaporization and supply of SiCl ₄ , GeCl ₄ , WF ₆ , TEOS, etc.).

[Prior Art] Conventionally, as a method for vaporizing and supplying raw materials for manufacturing semiconductor devices and optical fibers, the raw materials are stored in a thermostatic chamber using forced convection using a fan and a heater with fins, without using a carrier gas. There is a method of controlling the flow rate by accommodating a container, a mass flow meter, piping between them, and necessary valves and keeping them at a high temperature. Figure 3 shows its configuration, in which a constant temperature bath 1 contains a raw material container 2, a mass flow meter 3,
The valves 4, 4, ... necessary for switching the flow paths and the piping 5 connecting them are arranged, and the heat of the finned heater 6 to keep them at high temperature is circulated by forced convection by the fan 7 to maintain a constant temperature. The inside of the tank is kept at a high temperature.

However, when controlling the vaporization of raw materials using such an apparatus, the following problems occur.

(1) In the case of forced convection in the thermostatic chamber 1, since there are piping 5, raw material containers 2, etc. inside the thermostatic chamber, there are areas where the air is easily exposed and areas where it is difficult to reach. As a result, if there is a low-temperature part in the piping 5, liquefaction of the liquid raw material may occur, and if a high-temperature part is near the mass flowmeter 3, there is a risk that flow rate control will be hindered.

Furthermore, each time the design of the piping is changed, the degree of airflow changes, which requires temperature measurement and adjustment, which increases the design cost.

(2) The gas flow path of the mass flow meter 3 and the gas flow path of the valve are made of SUS316 square material, etc.
The heat capacity was extremely large, and it took a long time to maintain a uniform temperature inside the thermostatic chamber 1 using forced convection alone.

(3) A space is required between the fan 7 and the heater 6 with fins, and a space between the valves and the like for improving ventilation, making the device large-scale.

[Problems to be solved by the invention] In the above-mentioned raw material vaporization and supply device, it is not necessary that each part in the thermostatic chamber has a uniform temperature with high precision. There are areas where the temperature can be lower in the range, areas where the temperature can be slightly higher, such as gas purge lines, areas where the temperature can be kept at a strictly constant temperature, such as areas near the mass flow meter 3, pipes 5 and valves 4 where raw materials flow. It can be divided into the necessary parts.

Taking these points into consideration, the present invention solves the above-mentioned conventional problems by simple means, and
The present invention aims to provide a raw material vaporization and supply control device that can control each part within an appropriate temperature range.

[Means for solving the problem] In order to achieve the above purpose, in the present invention,
In a raw material vaporization and supply control device that heats and vaporizes the raw material contained in a raw material container and sends the vaporized raw material through a mass flow meter, a valve, and a raw material gas supply piping that connects them, the inside of the thermostatic chamber is heated and vaporized. The upper chamber is divided into upper and lower chambers by a built-in heating plate, and in the upper chamber, the mass flow meter and valve passage forming member are closely attached to the temperature-controlled heating plate, and the source gas supply piping connects them. A technical measure is adopted in which a container is placed at a desired height and a raw material container is placed in the lower chamber, which is controlled to maintain a constant temperature of the raw material inside.

[Function] The passage forming members of mass flowmeters and valves that are placed in close contact with the heating plate have a large heat capacity, but because they are heated by direct heat conduction from the heating plate, it takes a long time to reach a constant temperature. is shortened. Furthermore, since the mass flow meter, valves, and piping connecting them are appropriately arranged in the upper chamber partitioned by the heating plate, each part can be controlled within an appropriate temperature range by simple means.

[Embodiment] FIGS. 1 and 2 show an embodiment of the raw material vaporization and supply control device according to the present invention.

In this raw material vaporization supply control device, a heating plate 12 with a built-in heater is arranged horizontally in a constant temperature chamber 11 surrounded by a wall of heat insulating material.
The interior is divided into an upper chamber 13 and a lower chamber 14.
The heating plate 12 is not intended to airtightly partition the interior of the thermostatic chamber 11 into upper and lower sections, but rather to prevent a large air flow from occurring between the upper chamber 13 and the lower chamber 14.

The heating plate 12 has a heat insulating layer 15 as the lower layer, a heat transfer plate 16 made of a material with good thermal conductivity such as stainless steel or aluminum on the upper layer, and a thin plate on the necessary parts of the upper layer. A heater 17 of a shape is placed in close contact with the heater 17.

In the upper chamber 13 partitioned by the heating plate 12, a mass flow meter 20, valves 21, 21, etc. necessary for switching the flow paths, and raw material gas supply piping 22 connecting these are arranged. The flow meter 20 and the valve 21 are made of passage forming members 20a, 2 having a large heat capacity and having a fluid passage formed therein.
In order to directly heat 1a by thermal conduction, it is attached in close contact with the heating plate 12. In the illustrated embodiment, a mass flow meter 20, a valve 21
are installed on the heater 17, but since the heat transfer plate 16 provided on the heating plate 12 ensures good heat transfer over almost the entire surface, it is not necessary to provide them on the heater 17.

The temperature of the upper chamber 13 is controlled by passage forming members 20a and 2 of the mass flowmeter 20, which require strict temperature control.
This is achieved by attaching a temperature sensor 23 to 1a and adjusting the heating by the heater 17 according to the output of this temperature sensor 23. The temperature of the source gas supply pipe 22 connecting between the valve 21 on the heating plate 12 and the mass flow meter 20 etc. is controlled in the upper chamber 13.
The parts of the pipes 2 to be maintained at the same temperature are located at the same height from the heating plate 12, thereby keeping the pipe temperature constant.

The raw material gas supply piping is connected to heating plate 1.
For example, it is possible to set a temperature gradient depending on the distance from the heating plate 12, for example, for piping where raw materials do not flow such as a purge line, for piping where you want to set the temperature to be different from other piping, or for piping where you want to set the temperature to be different from other piping, or by changing the distance from the heating plate 12. By changing the temperature, it is also possible to appropriately incline the pipe temperature.

The upper chamber 13 includes a mass flowmeter 20 and a valve 2.
Since the upper chamber 13 is installed as the main body and the temperature inside the room is controlled, it is desirable to make the height of the upper chamber 13 itself as low as possible by the height necessary for the installation, and generally the height is set to 20cm or less. In this way, it is extremely important to make the height of the upper chamber 13 as low as possible in order to keep the pipe temperature constant without installing a finned heater or fan for forced convection in the upper chamber 13. It is valid.

Further, in the above embodiment, in order to maintain the upper chamber 13 at a higher temperature than the lower chamber 14, a heat insulating layer 15 is disposed below the heating plate 12, but depending on how the temperature of both chambers is set, , this heat insulating layer 15 can also be omitted.

On the other hand, a raw material container 24 is disposed in the lower chamber 14. Since the temperature inside the raw material container 24 drops due to the heat of vaporization of the raw material, a thermometer 25 and a heater 26 are separately installed.
are used to control the raw material temperature to a constant level.

Note that it is also possible to have multiple stages of the heating plate 12 and to separately adjust the temperature of the chambers partitioned by each stage.

In the raw material vaporization supply device having the above configuration, a mass flowmeter 2 is mounted on the heating plate 12.
Since the passage forming members 20a and 21a of the valve 21 and the valve 21 are brought into close contact with each other and heated by direct heat conduction, the time required to bring the passage forming members having a large heat capacity to a constant temperature is shortened.

Moreover, the passage forming member 20a of the mass flowmeter 20,
Since temperature control is performed by attaching a temperature sensor 23 to 21a, the temperature of the mass flowmeter 20 can be adjusted with high precision, and the valve 21 and piping 22 installed in the same upper chamber 13 as the mass flowmeter 20 can also be adjusted. It is possible to adjust the temperature with relative accuracy and in a manner suitable for these conditions.

Furthermore, when changing the design of this device or creating a new design, each element should be arranged on the heating plate in the upper chamber 13 and on the lower chamber 14, and the piping 22 should be arranged at an equal distance from the heating plate 12. Since it is possible to perform the desired temperature control with just the fan, there is no need to measure the temperature that changes depending on the wind blowing condition in advance, unlike when using a fan, and therefore the design cost is reduced.

[Effects of the invention] As detailed above, according to the raw material vaporization supply control device of the invention, it is not necessary that each part in the thermostatic chamber has a uniform temperature with high precision, but within a range of several degrees Celsius. Considering that there are parts that require a lower or higher temperature, and parts that require a strictly constant temperature, it is possible to quickly control each part to an appropriate temperature range using simple means that do not require design costs. Moreover, unlike conventional devices, there is no need to provide a finned heater or fan for forced convection, so the volume of the thermostatic chamber can be reduced accordingly.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a raw material vaporization and supply control device according to the present invention, FIG. 2 is a horizontal sectional view thereof, and FIG. 3 is a longitudinal sectional view of a conventional raw material vaporization and supply control device. 11... Constant temperature chamber, 12... Heating plate, 13... Upper chamber, 14... Lower chamber, 17, 26...
...Heater, 20...Mass flow meter, 20a, 21a
... Passage forming member, 21 ... Valve, 22 ... Raw material gas supply piping, 24 ... Raw material container.

Claims (1)

[Claim for Utility Model Registration] Raw material vaporization and supply control that heats and vaporizes the raw material contained in a raw material container and sends the vaporized raw material through a mass flow meter, a valve, and a raw material gas supply pipe that connects them. In the device, the inside of the constant temperature chamber is divided into upper and lower chambers by a heating plate with a built-in heater, and in the upper chamber, the mass flow meter and the passage forming member of the valve are closely mounted on the heating plate whose temperature is controlled. A raw material vaporization system characterized in that a raw material gas supply pipe connecting these is arranged at a required height, and a raw material container that is controlled to keep the internal raw material temperature constant is arranged in the lower chamber. Supply control device.