JP3072226B2 - Decaborane supply method in decaborane gas supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decaborane gas supply system. In more detail, decaborane, which is solid at room temperature and easy to handle, is obtained at a normal temperature, which is a kind of hydrogenated boron compound represented by diborane, which requires special care in handling, to obtain decaborane gas, and to control the gas flow rate This system is capable of stably supplying decaborane gas at a specified flow rate by a valve (mass flow controller), and safely exhausting decaborane gas that has become unnecessary to supply with a vacuum pump via a scrubber. In addition, the present invention relates to a decaborane gas supply system capable of suppressing and stopping generation of decaborane vapor pressure by cooling a heating unit in an emergency. The vapor pressure characteristics when decaborane was heated are as shown in FIG.

[0002]

2. Description of the Related Art Conventionally, hydrogenated boron compounds such as diborane and trimethylboron have been used as materials for semiconductor doping, boron coating, and the like. It was necessary to convert the equipment to equipment with safety measures that satisfied the legal regulations, and to construct the equipment to be manufactured as equipment with safety measures that satisfied the legal regulations. For semiconductor manufacturers, etc.,
The facility and work environment are being improved with an emphasis on safety.

On the other hand, in a research and development institution that conducts research and development, it is not suitable to use a special material gas in order to obtain a research result at an early stage. There was a need for a working gas supply system for coating that could be easily performed. Therefore, attention has been paid to the use of decaborane, a kind of hydrogenated boron compound, which is solid at room temperature and easy to handle. Since decaborane is a safe material that is easy to handle and solid at room temperature, it is suitable for materials used in research and development (boron coating, etc.). There was no example.

[0004] However, for the supply of decaborane gas using decaborane, there have been experimental devices or the like in which decaborane is packed in a pipe and heated by a ribbon heater or the like to supply a vapor pressure, but these are clogged due to uneven temperature. And a long cooling time. In addition, there is no device to which decaborane gas is applied even in a single device such as a gas leak detector, an abatement apparatus, and a mass flow controller.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has been made in consideration of the following problems.
Construct a gas supply system that combines abatement equipment, gas leak detectors, raw material containers, etc., heat and heat the entire system to obtain decaborane gas, and can supply decaborane gas safely and stably. Can be safely evacuated with a vacuum pump through the abatement system, and in an emergency, the heating section is cooled to suppress the generation of decaborane vapor pressure,
It is an object to provide a decaborane gas supply system that can be shut down.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a decaborane gas supply system using a gas supply combining a stainless steel pipe, a metal seal valve, a mass flow controller, a raw material container, a pressure detector and the like. The line is constructed with a gas exhaust line that combines a metal seal valve, vacuum pump, pressure gauge, abatement device, etc., and the main part of the gas supply line (mass flow controller, raw material container, pressure detector, etc.) is heated and opened. So that the whole can be heated uniformly, stainless steel piping,
The metal seal valve and the like are structured so that a heater can be attached to heat them, and furthermore, the pipes and equipment are all kept warm by a heat insulating material so that temperature unevenness does not occur. The main heating section and the abatement system have a structure in which a gas leak detector is arranged to detect gas if decaborane gas leaks.

The decaborane is filled in a raw material container, and heated together with a mass flow controller, a raw material container, a pressure detector, and the like connected inside the opening so as to obtain a predetermined decaborane vapor pressure. Stainless steel pipes, metal seal valves, etc. are heated so that decaborane gas does not recrystallize during the movement. The decaborane gas is controlled to an arbitrary flow rate by a mass flow controller, and when the decaborane gas is transferred to a vacuum vessel or a reaction tank (process) that has been evacuated, the piping is kept in a negative pressure state. It is supplied as working gas for chemical treatment. The decaborane gas that is no longer needed in the system is safely exhausted by a vacuum pump through a detoxification device or the like.

[0008] Further, when stopping an arbitrary flow rate of the decaborane gas during control, the metal seal valve and the mass flow controller can be closed, and the open heating can be stopped to control and stop the decaborane vapor pressure. After that, unnecessary decaborane can be installed and removed while being filled in the raw material container, and the entire decaborane gas supply system can be constructed in an open space according to the scale of the equipment, and the entire system can be constructed with heaters and heat insulating materials To provide a decaborane gas supply system.

[0009]

According to the present invention, in a decaborane gas supply system, for example, when decaborane gas is supplied to a vacuum vessel or a reaction vessel, solid decaborane at room temperature is filled into a raw material container and connected to an open gas supply line. Heat to the specified temperature, and obtain the desired decaborane vapor pressure by heating the metal seal valve, pressure gauge, piping, etc. to the specified temperature with a heater and a heat insulator, and the raw material container, mass flow controller, etc. to the specified temperature (open). Can be.

[0010] The decaborane gas can be supplied to a vacuum vessel or a reaction tank by controlling an arbitrary gas flow rate by a mass flow controller. When decaborane vapor pressure is generated or decaborane gas is supplied, the gas is supplied to the vacuum vessel or the reaction tank in a negative pressure state. Therefore, even if a leak occurs in the gas supply line, gas leakage can be prevented. When decaborane gas is not required, the gas supply line valve can be closed and exhausted by a vacuum pump such as a turbo molecular pump or an oil rotary pump of a gas exhaust system. The exhaust gas is diluted with an inert gas, and can be processed into a stable and safe substance by a scrubber and exhausted.

When the decaborane vapor pressure is controlled or the supply of decaborane gas is stopped due to a demand for a vacuum vessel or a reaction tank or an abnormality in the system, the heating temperature is controlled or a cooling fan built in the oven is used. By operating the (cooling fan) or urgently returning the heating temperature to the normal temperature, the decaborane gas in the raw material container or the like can be recrystallized into safe solid decaborane.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a decaborane gas supply system according to the present invention. Conventional material gas supply systems such as semiconductor doping and boron coating using boron hydride compounds such as diborane and trimethylboron, the supply pipe is a vacuum double pipe, or, while a triple pipe, a valve,
A gas flow control device, pressure gauge, material gas, etc. are housed in a cylinder cabinet (gas cabinet), and the system is designed to dilute and exhaust the inside of the cabinet. It is not a complete evacuation system because of simple evacuation. When handling diborane, trimethylboron, and the like, special equipment such as an air breathing apparatus and flameproofing clothes are required, and all systems are remotely operated.

FIG. 1 shows the configuration of a decaborane gas supply system according to the present invention. In this example,
In the case of boron coating or the like, the vacuum vessel, the reaction tank, and the like are heated (baked) to a high temperature. The system configuration of the present invention comprises 42 raw material containers, 7 diaphragm gauges, 41
Diaphragm gauge, 22 decaborane valve, 24 decaborane valve, 30 mass flow controller, 31 mass flow controller, 21 decaborane valve, 23 decaborane valve, 6 diaphragm gauge, 40 diaphragm gauge, 10 gate valve, 45 gas leak detector, 4
A gas supply line composed of 6 gas leak detectors, 27 leak valves, piping, a heating oven, a heater, a heat insulating material (heating range), etc., 16 exhaust valves, 33 abatement equipment,
15 exhaust valve, 35 dilution valve, 36 dilution valve, 9
Oil mist trap, 8 oil filtrations,
1 rotary pump, 5 Pirani gauge, 13 exhaust valve, 2 turbo molecular pump, 3 ion gauge, 4 Pirani gauge, 12 exhaust valve, 11 exhaust valve, 14 exhaust valve, 17 leak valve, 18 leak valve, 19 leak valve, 20 leak valve , A decaborane gas supply system including a decaborane gas exhaust line composed of 32 mass flow valves, piping and the like.

A diluting gas [inert gas (nitrogen gas): N ₂ ] is injected. Furthermore, a 25 helium valve, a 37 helium valve, a 3 helium valve, a 3 helium gas, etc.
4 heating filters, 29 mass flow controllers, 38
A helium gas supply line including a mass flow controller, a 26 helium valve, a 39 helium valve, and piping is added. Note that the heating filter is for heating the helium gas so as not to thermally affect decaborane, which is a working gas.

The decaborane is obtained by connecting a raw material container filled in a solid state to a raw material container in an atmosphere of an inert gas such as helium gas to a supply mounting portion of a heating oven, and by using a rotary pump via a 14 exhaust valve. After exhausting the atmosphere or an inert gas such as helium gas, the oven is heated to obtain a vapor pressure. The vapor pressure of decaborane is about 3 × 10 ³ Pa (Pascal) at 110 ° C. as shown in FIG.
Is obtained. The piping is heated by a heater and a heat insulating material (heating range) so that the decaborane gas does not recrystallize (if the heat retention is insufficient, the decaborane gas recrystallizes, causing troubles such as line clogging). The decaborane gas is supplied in advance to the 101 gate valve, 1
02 diaphragm gauge, 103 ion gauge, 104
Turbo molecular pump, 105 leak valve, 106 exhaust valve, 107 exhaust valve, 108 Pirani gauge, 109
Rotary pump, 110 oil filtration,
111 oil mist trap, 112 exhaust valve, 11
3 abatement system, 114 exhaust valve, 115 break monitor, 116 N2 nitrogen gas, 117 RGA (residual
gas analyzer) Residual gas analyzer, 118 leak valve, 119 leak valve, 120 mass flow controller, 121 MFD Exhaust manifold etc. 10 gate valves, 21 decaborane valves, 22 decaborane valves, 23 decaborane valves, and 24 decaborane valves are opened, and supplied under the control of 31 mass flow controllers and 30 mass flow controllers.

The detoxification device is a stainless steel cylinder filled with an alkaline oxidizing agent. When decaborane gas passes through the device, it chemically reacts with the alkaline oxidizing agent to change into a stable substance. Decaborane is to be harmed. The MFD is a manifold (M
ANIFOLD), which is a tube (parent port) with many branch ports (small ports to which devices are attached), and in the present invention, there is a manifold (MFD) in which various devices are attached from a vacuum vessel, An exhaust system is connected to some of the ports.

FIG. 3 shows the decaborane gas flow rate characteristics of the mass flow controller. These characteristics show the control characteristics of 2, 4, 6, 8, and 10 SCCM with nitrogen gas and the control characteristics of 2, 4, and 10 SCCM with decaborane gas. When the differential pressure is low, a high flow rate can be obtained. However, when the differential pressure is high, a stable flow rate can be obtained. Even when decaborane gas is controlled by decaborane vapor pressure, stable control can be obtained. That is, the inside of the system is heated (in a normal state), nitrogen gas is set at 2, 4, 6, 8, and 10 SCCM to check the controllability at each flow rate, and then 2, 4, 1 with decaborane gas.
At 0 SCCM, controllability and stability at each flow rate were confirmed. In particular, they were confirmed at low amounts of 2 SCCM. As a result, a heating mode and a heating method were established. Note that the SCCM is a standard cub.
ic centimeter perminutes, flow rate per minute at 0 ° C. and 1 atm (c
c / min).

FIG. 4 shows residual gas analysis in a 117 RGA residual gas analyzer when decaborane gas is supplied to the process side (vacuum apparatus side). The upper diagram shows a spectrum when decaborane gas is decomposed by glow discharge in a vacuum vessel, a reaction tank, or the like. Since boron is decomposed by glow discharge, no boron-based spectrum is observed. The lower figure shows the spectrum when only decaborane gas was supplied to the vacuum vessel or the reaction tank, and the spectrum was boron-based because it was pyrolyzed. Note that B ₅ , B ₆ ,
B ₇ , B ₈ , B ₉ and B ₁₀ are each 5 molecules of boron,
The patterns of 6, 7, 8, 9 and 10 molecules are shown.

When the supply of decaborane gas is stopped to stop the vapor pressure of decaborane due to the occurrence of an abnormality in the vacuum vessel, the reaction tank, the equipment, etc., a 22 decaborane valve, 24
Close the decaborane valve (verify that the valves 12, 14, and 27 are closed), stop heating only the oven, open the 28 leak valve, perform forced cooling with nitrogen gas, open the 35 dilution valve, Cool to room temperature while evacuating the oven. By cooling, the vapor pressure of decaborane can be suppressed or stopped, and solid decaborane can be recrystallized.

When the supply of decaborane gas is no longer necessary in a vacuum vessel or a reaction tank during the supply of decaborane gas, 21, 23, 11, 25 are closed so as not to leave decaborane in the system, and 31, 30, Open 22, 24, 12 and 2,
The exhaust can be safely performed through the first and the third 33. If the abatement capacity is reduced during exhaust, each break monitor is activated and can be safely stopped.

When decaborane gas leaks during decaborane vapor pressure generation, decaborane gas exhaustion, decaborane gas exhaustion, etc., each gas leak detector is operated to stop safely. The main equipment used in the present invention, the mass flow controller, abatement equipment, gas leak detector, break monitor, etc., was developed exclusively for diborane, but here, with decaborane gas,
Preliminary tests have confirmed that diborane can be converted to decaborane by partial calibration.

[0022]

As described in detail above, the decaborane gas supply system of the present invention is easy and
A raw material container accurately filled with decaborane is heated by an oven to obtain an arbitrary vapor pressure, and it is possible to stably supply decaborane gas to the process side via a heated supply pipe, and supply is not required It is possible to remove the decaborane gas and exhaust it safely. In an emergency, it is possible to cool the raw material container to suppress the vapor pressure of decaborane and stop the supply of decaborane.

[Brief description of the drawings]

FIG. 1 is a diagram showing a decaborane gas supply system and a gas exhaust system of the present invention.

FIG. 2 is a diagram showing vapor pressure characteristics obtained when decaborane gas of the present invention is heated.

FIG. 3 is a diagram showing a flow rate characteristic by a mass flow controller and a flow rate characteristic by decaborane gas implemented with nitrogen gas in the decaborane gas supply system of the present invention.

FIG. 4 is a diagram showing a residual gas analysis result when decaborane gas is supplied to the process side of the present invention.

[Explanation of symbols]

1: Rotary pump 2: Turbo molecular pump 3: Ion gauge 4: Pirani gauge 6: Diaphragm gauge 7: Diaphragm gauge 8: Oil filtration 9: Oil mist trap 10: Gate valve 11: Exhaust valve 12: Exhaust valve 13: Exhaust valve 14: Exhaust valve 15: Exhaust valve 16: Exhaust valve 17: Leak valve 18: Leak valve 19: Leak valve 20: Leak valve 21: Decaborane valve 22: Decaborane valve 23: Decaborane valve 24: Deca Borane valve 25: Helium valve 26: Helium valve 27: Leak valve 28: Leak valve 29: Mass flow controller 30: Mass flow controller 31: Mass flow controller 32: Mass flow controller 33: abatement device 34: heating filter 35: dilution valve 36: dilution valve 37: helium valve 38: mass flow controller 39: helium valve 40: diaphragm gauge 41: diaphragm gauge 42: raw material container 43: nitrogen gas 44: helium gas 45 : Gas leak detector 46: Gas leak detector 47: Break monitor 48: Break monitor 101: Gate valve 102: Diaphragm gauge 103: Ion gauge 104: Turbo molecular pump 105: Leak valve 106: Exhaust valve 107: Exhaust valve 108: Pirani gauge 109: Rotary pump 110: Oil filtration 111: Oil mist trap 112: Exhaust valve 113: Abatement device 114: Exhaust valve 115: Break monitor 116: Nitrogen Scan 117: residual gas analyzer 118: leak valve 119: leak valve 120: the mass flow controller 121: exhaust manifold

Continuation of the front page (56) References JP-A-6-154579 (JP, A) JP-A-3-104868 (JP, A) JP-A-60-238136 (JP, A) JP-A-59-158435 (JP) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 4/00, 7/00 H01L 21/22

Claims (2)

(57) [Claims] 1. Decaborane (B ₁₀ H ₁₄ ), which is solid at room temperature and easy to handle, is heated to obtain decaborane gas, and a specified gas flow rate can be stably supplied by a gas flow rate control valve. In a decaborane supply method in a decaborane gas supply system capable of safely removing decaborane gas that has become unnecessary to supply, a decaborane gas supply system and a decaborane gas exhaust system are provided in a vacuum vessel or a reaction tank in which decaborane gas is used, and the decaborane gas supply is provided. The system is provided with a heating and heat retaining mechanism to perform heating so that recrystallization does not occur during the movement of decaborane.The decaborane gas supply system is provided with a helium gas supply line equipped with a heating filter, and the decaborane gas as the working gas is thermally affected. Not like that supporting gas A certain helium gas is heated by the heating filter and introduced into a vacuum vessel or a reaction vessel, a source vessel for solid decaborane is provided in the decaborane gas supply system, and a pump is connected to the source vessel via an exhaust valve to supply the source vessel. After degassing and exhausting the gas mixed at the time of installation through the detoxifying device by the pump, the raw material container is heated to generate decabon gas, and the generated decaborane gas is supplied to the vacuum container or the reaction vessel together with the supporting gas,
The decaborane gas exhaust system is also provided with an abatement apparatus, and the vacuum vessel or the reaction tank is connected to the abatement apparatus via a pump to perform the abatement evacuation in the vacuum vessel or the reaction tank, and then the decaborane gas is supplied. . 2. In an emergency, the heating section of the raw material container is cooled to suppress and stop the generation of decaborane vapor, and recrystallized into decaborane which is solid and easy to handle by cooling. the method of.