JPH0714299U - Gas supply piping - Google Patents

Abstract

(57) [Summary] [Objective] To provide a gas supply pipe for stably supplying a liquefied gas having a low boiling point. A gas supply pipe 1 includes an inner pipe 2 for supplying a gas supplied from a gas cylinder to a semiconductor manufacturing apparatus, a clamp 3 for connecting the inner pipe 2, an outer pipe 4 surrounding the inner pipe 2, and an outer pipe 4.
It comprises a support 5 for supporting the inside, a sheath heater 6 provided on the inner tube 2, and a CA thermocouple 7 for controlling the temperature of the sheath heater 6. The vacuum heat insulating layer 8 between the outer wall of the inner tube 2 and the inner wall of the outer tube 4 is vacuum insulated to a vacuum state of 1 × 10 ⁻⁴ Torr or less by a vacuum pump connected to the inner tube 2 and the outer tube 4. To minimize the heat flow value of the outer wall of the inner tube 2 and the outer tube 4
Since the temperature change due to the convection of the atmosphere of the inner wall is blocked, the influence of the temperature change due to the convection of the atmosphere is not exerted on the supply gas.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

The present invention relates to a gas supply pipe used for supplying gas from a gas supply source to a semiconductor manufacturing apparatus, and more specifically, tungsten hexafluoride (WF ₆ ), dichlorosilane (SiH ₂ Cl ₂ ), etc. The present invention relates to a gas supply pipe that can stably supply a liquefied gas having a low boiling point even when the external temperature is likely to change or the temperature difference between the gas supply pipe and the outside is large.

[0002]

[Prior art]

Liquefied gases with a low boiling point such as tungsten hexafluoride (WF ₆ ) and dichlorosilane (SiH ₂ Cl ₂ ) are often used in manufacturing semiconductor devices. Conventionally, when supplying these gases from a gas supply port of a gas cylinder to a gas intake port of a semiconductor manufacturing apparatus, they are supplied through a single-layer gas supply pipe. When the gas is supplied, it is predicted that there will be a temperature change in the atmosphere between the gas supply port of this gas cylinder and the gas outlet, or a local temperature change in the gas supply pipe. Since there is a temperature gradient and the supply gas is liquefied, the gas supply becomes unstable. In order to prevent the effect of such temperature changes, a heater is installed in the gas supply pipe, and the heater is used to heat the gas supply pipe to create a temperature gradient and prevent liquefaction of the gas in the gas supply pipe. ing .

[0003]

[Problems to be solved by the device]

 However, since the semiconductor manufacturing equipment is equipped with a large number of precision instruments, the heating temperature of the heater is generally limited. Therefore, the temperature of the supply gas cannot be effectively controlled, which is inconvenient for stable supply of the gas. The present invention solves the above problems, and stabilizes a liquefied gas with a low boiling point even when the temperature of the external atmosphere is likely to change or the temperature difference between the gas in the gas supply pipe and the external atmosphere is large. The purpose is to provide a gas supply pipe that can supply the gas.

[0004]

[Means for Solving the Problems]

The gas supply pipe of the present invention comprises an inner pipe for supplying gas and an outer pipe surrounding the inner pipe, and a vacuum state of 1 × 10 ⁻⁴ Torr or less is provided between the outer wall of the inner pipe and the inner wall of the outer pipe. It is characterized by A preferred embodiment of the gas supply pipe of the present invention is characterized in that the outer wall of the inner pipe and the inner wall of the outer pipe are electropolished. A preferred embodiment of the gas supply pipe of the present invention is characterized in that a heater is provided on the outer wall of the inner pipe.

[0005]

[Action]

The gas supply pipe of the present invention has a double structure of an inner pipe for supplying gas and an outer pipe surrounding the inner pipe, and a vacuum of 1 × 10 ^-4 Torr or less is provided between the outer wall of the inner pipe and the inner wall of the outer pipe. In this state, vacuum heat insulation is performed to minimize the heat flow value of the outer wall of the inner pipe and to block the temperature change due to the convection of the atmosphere of the outer wall of the outer pipe. Therefore, the influence of the temperature change due to the convection of the atmosphere does not affect the supply gas. Figure 1 shows a graph showing the relationship between pressure and heat flow due to residual gas when the hot wall is 95 ° C and the cold wall is 20 ° C. The vacuum condition of 1 × 10 ^-4 Torr or less between the outer wall of the inner tube and the inner wall of the outer tube was set to make the heat flow value of the outer wall of the inner tube as small as possible, and to keep it below 1 kcal / m ³ hr. When the temperature difference between the atmosphere of the outer wall of the outer tube and the supply gas is about 75 ° C, the space between the outer wall of the inner tube and the inner wall of the outer tube must be 1 × 10 ^-4 Torr or less as shown in Fig. 1. Because there is. Therefore, the liquefied gas having a low boiling point can be stably supplied even when the temperature of the external atmosphere is likely to change or the temperature difference between the supply gas in the inner pipe and the outside is large. In the preferred embodiment of the gas supply pipe of the present invention, since the outer wall of the inner pipe and the inner wall of the outer pipe are subjected to electric field polishing, the heat flow due to radiation is minimized, and as a result, the outer wall of the inner pipe and the inner wall of the outer pipe are Since the heat flow due to the gas between them can be ignored, the gas passing through the inner tube is not affected by the external temperature, and therefore the gas can be supplied more stably. Further, in the preferred embodiment of the gas supply pipe of the present invention, the temperature of the gas supplied by the inner pipe can be controlled by the heater, so that the gas can be supplied more stably without being liquefied.

[0006]

【Example】

Hereinafter, embodiments of the gas supply pipe of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a schematic configuration diagram of an embodiment of the gas supply pipe of the present invention. The gas supply pipe 1 includes an inner pipe 2 for supplying a supply gas from a gas cylinder (not shown) for supplying a gas such as WF ₆ or SiH ₂ Cl ₆ to a semiconductor manufacturing apparatus (not shown), and an inner pipe 2. A clamp 3 to be connected, an outer pipe 4 surrounding the inner pipe 2, a support 5 for supporting the inside of the outer pipe 4, a sheath heater 6 provided in the inner pipe 2, and a CA thermocouple for controlling the temperature of the sheath heater 6. 7 and. For example, a 1/4 SUS316EP pipe is used as the inner pipe 2, and a 3/8 SUS316EP pipe is used as the inner pipe 4, for example. In addition, the outer wall of the inner tube 2 and the inner wall of the outer tube 4 have been subjected to electrolytic polishing. A CA thermocouple 7 is provided for the sheathed heater 6 so that it can be controlled at an arbitrary temperature of 20 ° C to 100 ° C by using a PID control type temperature controller. The CA thermocouple 7 is taken out from the NW40KF leadthrough as a leadthrough, and is connected to each cable by a connector. The vacuum heat insulating layer 8 between the outer wall of the inner tube 2 and the inner wall of the outer tube 4 is 1 × 10 ⁻⁴ Torr or less by a vacuum pump (not shown) connected to the inner tube 2 and the outer tube 4. The vacuum state is maintained.

The gas supply pipe 1 has a double structure of an inner pipe 2 for supplying gas and an outer pipe 4 surrounding the inner pipe 2, and the reason why the space between the outer wall of the inner pipe 2 and the inner wall of the outer pipe 4 is described above. In this way, vacuum insulation is performed with a vacuum state of 1 × 10 ^-4 Torr or less. As a result, since the heat flow value of the outer wall of the inner tube 2 is minimized and the temperature change due to the convection of the atmosphere of the outer tube 4 is blocked, the influence of the temperature change due to the convection of the atmosphere does not affect the supply gas. Therefore, according to this example, liquefied gas with a low boiling point such as WF ₆ or SiH ₂ Cl ₆ is likely to change the temperature of the external atmosphere or the temperature difference between the supply gas in the inner tube 2 and the outside is large. Even in the case, it can be stably supplied.

Further, in this example, since the outer wall of the inner tube 2 and the inner wall of the outer tube 4 are subjected to the electric field polishing treatment, the heat flow due to radiation is suppressed to a minimum, and the outer wall between the inner tube 2 and the outer tube 4 is minimized. Since the heat flow due to the gas can be ignored, the supply gas passing through the inner pipe 2 is not affected by the external temperature, and therefore the gas can be supplied more stably. Furthermore, in this example, the temperature of the gas supplied by the inner pipe 2 can be controlled to any temperature of 20 ° C to 100 ° C by the sheath heater 6 and the CA thermocouple 7, so that the supply gas is further stabilized without being liquefied. Can be supplied to.

FIG. 3 is a block diagram of the joint portion of the outer pipe of the gas supply pipe of the present invention, and FIG. 4 is a sectional view of the joint portion of FIG. 3 taken along the line AA. The joint part of the gas supply pipe 1 consists of a combination of a vacuum bellows 11 and a VCR joint 12. In this example, the vacuum bellows 11 is a 40 KF bellows and the VCR joint 12 is SS-4-VCR-1, SS-4-VCR-. The one consisting of 2-GR and SS-4-VCR-4 is used. In this example, 316L-4-VCR-3A or 316L-4-VCR-3AS is used as the inner tube 2, and three WA-XX manufactured by Kawai Denki S / S, which are thin tube sheathed heaters, are used as the sheathed heaters 6, OMRON E52-CA15A is used as each CA thermocouple.

FIG. 5 shows a schematic configuration diagram when the gas supply pipe of the present invention is applied to a semiconductor manufacturing factory. In FIG. 5, on the first floor of the factory, there is a gas box 21, which is a gas supply source, and a turbo molecular pump 22 and a vacuum pump that maintain a vacuum state between the inner pipe outer wall and the outer pipe inner wall of the gas supply pipe 1. 23, and a semiconductor manufacturing apparatus 24 on the second floor. The gas supply pipe 1 connects between the gas box 21 and the semiconductor manufacturing device 24, but in this example, it is composed of three gas supply pipes 1 and is connected to each other by a joint 25 using a bellows. Are combined. Further, each of the three outer tubes is provided with two spare sheath heaters (not shown), that is, each outer tube is provided with a total of three sheath heaters. Each sheathed heater is equipped with a CA thermocouple (not shown), and as described above, it is possible to control to an arbitrary temperature of 20 ° C to 100 ° C by using the temperature controller of the PID control system. The CA thermocouple is taken out from the NW 40KF leadthrough as a leadthrough and connected to each cable with a connector. As described above, the gas supply pipe of the present invention can be arranged in conformity with various building structures.

FIG. 6 shows the structure of the inner pipe of the gas supply pipe of FIG. 5, and FIGS. 7 and 8 show enlarged views of the connecting portion of the inner pipe. In this example, the inner pipe 4 is composed of three inner pipes, and the connecting portions 31 and 32 are connected by the joints shown in FIGS. 7 and 8. Also, in this example, 40FK cloth and 40KF bellows are used for the connecting portion 31, and 40KF tees, 40KF bellows and 40KF tee with 1/4 tube diameter are used for the connecting portion 32.

[0012]

[Effect of device]

According to the gas supply pipe of the present invention, the inner pipe for supplying gas and the outer pipe surrounding the inner pipe have a double structure, and the distance between the outer wall of the inner pipe and the inner wall of the outer pipe is 1 × 10 ⁻⁴ Torr or less. In this state, vacuum heat insulation is performed to minimize the heat flow value on the outer wall of the inner tube and to block the temperature change due to the convection of the atmosphere on the outer wall of the outer tube.Therefore, the temperature change due to the convection of the atmosphere affects the supply gas. Not done. Therefore, even if the temperature of the external atmosphere is likely to change or the temperature difference between the supply gas in the inner pipe and the outside is large, the liquefied gas having a low boiling point can be stably supplied. In addition, since the gas supply pipe of the present invention has a double structure, even if gas leakage occurs from the inner pipe, there is a risk of gas leakage, for example, by attaching a gas sensor to the vacuum pump connected to the inner pipe. It can be prevented in advance, and measures are taken to reduce the occurrence of accidents. According to the preferred embodiment of the gas supply pipe of the present invention, since the outer wall of the inner pipe and the inner wall of the outer pipe are subjected to electric field polishing, heat flow due to radiation is minimized, and as a result, the outer wall of the inner pipe and the inner wall of the outer pipe are reduced. Since the heat flow due to the gas between and is negligible, the gas passing through the inner pipe is not affected by the temperature of the outer portion, and therefore the gas can be supplied more stably. Further, according to the preferred embodiment of the gas supply pipe of the present invention, since the temperature of the gas supplied by the inner pipe can be controlled by the heater, the gas can be supplied more stably without being liquefied. Have.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between pressure and heat flow value due to residual gas.

FIG. 2 is a schematic configuration diagram of an embodiment of a gas supply pipe of the present invention.

FIG. 3 is a schematic view of a joint portion of an outer pipe of a gas supply pipe of the present invention.

4 is a cross-sectional view of the joint portion of FIG. 3 taken along the line AA.

FIG. 5 is a schematic configuration diagram when the gas supply pipe of the present invention is applied to a semiconductor manufacturing factory.

6 is a structure of an inner pipe of the gas supply pipe of FIG.

7 is an enlarged view of a first connection portion of the inner pipe of FIG.

8 is an enlarged view of a second connecting portion of the inner pipe of FIG.

[Explanation of symbols]

 1 Gas Supply Pipe 2 Inner Pipe 3 Clamp 4 Outer Pipe 5 Supporter 6 Sheath Heater 7 CA Thermocouple 8 Vacuum Insulation Layer 11 Vacuum Bellows 12 VCR Joint 21 Gas Box 22 Turbo Molecular Pump 23 Vacuum Pump 24 Semiconductor Manufacturing Equipment 25 Joint 31, 32 Connection part

Claims (3)

[Scope of utility model registration request] 1. An inner pipe for supplying gas and an outer pipe surrounding the inner pipe are provided, and 1 is provided between the outer wall of the inner pipe and the inner wall of the outer pipe.
A gas supply pipe characterized by being in a vacuum state of 10 ⁻⁴ Torr or less. 2. The gas supply pipe according to claim 1, wherein the outer wall of the inner pipe and the inner wall of the outer pipe are electropolished. 3. The gas supply pipe according to claim 1, wherein a heater is provided on the outer wall of the inner pipe.