JP3474220B2 - Gas treatment equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a gas treatment device.

[0002]

2. Description of the Related Art Generally, in a semiconductor wafer manufacturing factory, a work area is separated into a clean room and a maintenance room, a wafer transfer system is arranged in the clean room, and a gas supply system and an exhaust system in a heat treatment apparatus are installed. It is installed in the maintenance room.
When a wafer is subjected to film formation processing or etching processing, gas with a high risk of flammability, flammability, or toxicity is used, so a gas cylinder is installed outdoors, for example, and the gas from here is the gas in the maintenance room. It is designed to be supplied into the reaction tube of the processing apparatus through a pipe.

On the other hand, in recent semiconductor manufacturing facilities, the number of processing processes is increasing and becoming complicated, so that there is a tendency to make the whole system compact, and the gas supply system is also made compact and easy to maintain. In order to achieve versatility of the system, integration of gas control equipment to form a gas control equipment unit has been considered.For example, this unit is installed integrally with an exhaust system unit adjacent to a heat treatment furnace, or It is also being considered to arrange it above the heat treatment furnace.

FIG. 4 shows a conventional example of a gas supply system of a heat treatment apparatus. In this gas supply system, a pipe 12 made of, for example, stainless steel is connected to a gas cylinder 11, and the pipe 12 is provided with a pressure reducing valve RG1 and a hand valve 13. And pressure reducing valve R
G2 is inserted. Further, for example, on the downstream side of the pressure reducing valve RG2, a gas control device unit U in which the gas control device is unitized is provided, and on the downstream side thereof, the heat treatment section 1 is provided.
0 is connected.

This gas control equipment unit U will be described with reference to the explanatory view of FIG. 4. A filter F1, a pressure switch 14, a mass flow controller (flow rate control unit) 15, a shutoff valve 16, a check valve 17, and an opening / closing valve. 18 and the filter F2 are collectively housed in a housing, and an air introduction pipe and an exhaust pipe are connected to the housing to allow, for example, air to flow in the housing to leak gas from the unit into the maintenance room. Is being prevented. Actually, the gas supply system is provided with a plurality of piping systems so as to be compatible with various heat treatments, and the gas control equipment unit U has a complicated three-dimensional structure.

[0006]

By the way, in the gas control equipment unit U, there are electric parts such as electric contacts, integrated circuits and connector portions. For example, some of the pressure switches 14 have a pressure signal output function and a switch function. In this case, the pressure switch 14 has a signal output circuit, a micro switch, a relay, and the like mounted therein. Also mass flow controller 1
Reference numeral 5 is provided with a processing circuit for outputting a flow rate control signal according to the flow rate detection value, and the shutoff valve 16 is provided with an electromagnetic valve for supplying air for shutoff operation.

Here, for example, when the flammable gas leaks from the connecting portion between the gas control equipment and the pipe, etc., air leaks from the exhaust duct because the air flows through the housing of the gas control equipment unit U. However, since the explosion region concentration is partially formed, if a spark occurs from the contact of the pressure switch 14 or the contact of the air control solenoid valve of the shutoff valve 16 in such a situation, or An explosion occurs when a spark is generated due to a poor electrical circuit connection. Even if a combustion-supporting gas such as oxygen leaks out even if it is not a combustible gas, ignition may spread from a spark or an overheated part, leading to a fire. When such an explosion or fire occurs in the gas control equipment unit, there is a great risk that the piping will burst or the gas control equipment will be damaged.In this case, the gas in the piping suddenly spurts into the factory, causing a large It will lead to accidents such as explosions and gas poisoning.

The present invention has been made under such circumstances, and an object thereof is to provide a gas treatment device capable of preventing gas explosion and fire due to sparks of electric parts. It is in.

[0009]

Means for Solving the Problems The plurality of gas control device is connected to the gas treatment unit via a gas pipe, gas control devices
Controls the gas control equipment and this gas control equipment body.
In the gas processing apparatus ing and an electric component other to perform the retrieval of the detection signals, a plurality of gas control apparatus main body, housed in a common housing portion having a gas leakage prevention structure, the <br/> electrical components Is arranged outside the storage part. The storage unit is configured by, for example, a housing having a closed structure in which a ventilation pipe on the introduction side and a ventilation pipe on the exhaust side are connected. As gas control equipment, pressure switch, mass flow control
La, shut-off valve, etc. Also, electrical parts
For example, it is housed in an airtight case . The gas processing unit is, for example, a heat treatment unit that heat-treats an object to be processed carried into a reaction tube with a processing gas under a heating atmosphere.

[0010]

The gas is supplied from the gas supply source to the gas processing unit, for example, the heat treatment unit, through the gas pipe in which the gas control device such as the on-off valve, the pressure switch, the mass flow controller, and the shutoff valve is inserted. Here, since electric parts such as the pressure signal circuit of the pressure switch and the micro switch are arranged outside the storage portion, it is possible to prevent the combustibility and the combustion supporting property from the connection portion between the gas control device and the pipe in the storage portion. Even if gas leaks, it will not come into contact with electrical parts. Therefore, even if the electric parts are sparked, they are separated from the gas leakage atmosphere, so there is little risk of explosion or fire, and safety is high.

[0011]

FIG. 1 is a diagram showing an embodiment in which the gas processing apparatus of the present invention is applied to a semiconductor wafer heat treatment apparatus. 2 in the figure
Is a gas cylinder, and a processing gas (including a carrier gas) such as hydrogen gas, oxygen gas, silane-based gas or halogen gas is enclosed in the gas cylinder 2 at a high pressure.

A gas pipe 21 made of, for example, stainless steel is connected to the gas cylinder 2 via a primary pressure reducing valve RG1 for primarily reducing the pressure of the high-pressure processing gas.
1, a hand valve 22 and a secondary pressure reducing valve RG2 are inserted, and a group of gas control devices, such as a filter F1, a pressure switch 3, a mass flow controller 4, a shutoff valve 5, a check valve 23, is provided on the downstream side thereof. The hand valve 24 and the filter F2 are provided in this order.

As will be described later in detail, these gas control equipments are housed in a housing portion, for example, a housing to form a gas control equipment unit 7. An injector 61 made of, for example, quartz or SUS stainless steel is connected to the gas pipe 21 on the downstream side of the gas control device unit 7 via a flexible pipe such as a Teflon tube (not shown). Tube 6 of heat treatment section 6
It is inserted in 2. The heat treatment section 6 is, for example, the reaction tube 6
2, a heater 63 installed so as to surround the reaction tube 62, a wafer boat 64 for loading and unloading a wafer W to be processed into the reaction tube 62, an exhaust pipe 65, and the like.

A tape heater 25 is wound around the gas pipe 21 in order to preheat the processing gas or to prevent dew condensation. However, in FIG. 1, only part of the tape heater 25 is shown for convenience of illustration.

Some of the gas control devices are combined with electric parts for taking out a detection signal and controlling the flow rate, pressure and gas supply / disconnection of the gas control device. The electric parts will be described. For example the pressure switch 3, the pressure sensing plate 32 of the case 31, a portion of the resistor 34 ho <br/> wells Stonebridge circuit 33 are attached, Hui preparative stone distortion of the pressure sensing plate 32 The pressure detected value is detected by the bridge circuit 33 and output to the controller 81, and when the detected pressure value exceeds the set value, the relay 35 issues an alarm signal to the controller 81.
It has a function to output to. Regarding the pressure switch 3, the electric components other than the resistor 34 are the circuit unit 36.
Mounted on the board.

The mass flow controller 4 has a flow rate detector 41, a flow rate controller 42, and a signal processor 43 that processes a detection signal of the flow rate detector 41 and outputs an operation signal to the flow rate controller 42. This signal processing unit 43
Is equipped with electric parts such as a control amplifier, and is ± V ₀
For example, a DC voltage of ± 15V is applied.

Further, the shutoff valve 5 is constructed so as to be shut off by the air from the air control unit 51, and the air control unit 51 includes a solenoid valve 52 and a circuit including a relay 53 for operating the solenoid valve. Is equipped with. Reference numeral 54 is an air supply pipe.

The electric components such as the circuit unit 36, the signal processing unit 43 and the air control unit 51 are housed in a casing separately from the gas control device unit 7 as described later to form an electric component unit 82. is doing. The connector 26 of the tape heater 25 is also incorporated in the electric component unit 82.

In the above example, one gas pipe system was described as an example. However, in an actual heat treatment apparatus, a large number of gas pipe systems are provided so as to cope with various heat treatments, and gas of each gas pipe system is provided. Since the number of control devices is also large, the number of gas control devices in the gas control device unit 7 is very large.
For example, FIG. 2 shows an example of the structure of the gas control equipment unit 7. In this gas control device unit 7, a ventilation pipe 72 on the introduction side and a ventilation pipe 73 on the exhaust side are connected to a housing 71 having a hermetically sealed structure, and air is circulated in the housing 71. Even if the gas leaks inside the housing 71, it has a gas leakage prevention structure that does not leak outside the housing 71.

The electric component unit 82 is separate from the gas control equipment unit 7, that is, the gas control equipment unit 7
A signal path for transmitting electric signals between the electric components and the gas control device is formed between the units 7 and 82 on the outside of the casing 71, for example, in the casing 83. A cable 84 including the above is connected. Further, a cable 85 for exchanging an alarm signal, a detection signal, or a control signal is connected between the electric component unit 82 and the controller 81.

FIG. 3 shows an overview of the entire apparatus in which the gas control equipment unit 7 and the electric component unit 82 are incorporated in a heat treatment apparatus. In the heat treatment unit 6, 66 is a carry-in / out port of the wafer carrier C, and 67 is a carrier stocker. The exhaust pipe 65 of the heat treatment section 6 is connected to the exhaust system unit 68 on the maintenance room side, and the gas control device unit 7 and the electric component unit 82 are located above the exhaust system unit 68, for example.

Next, the operation of the above embodiment will be described. First, after loading a large number of wafers W into the reaction tube 62 of the heat treatment section 6 by the wafer boat 64, the inside of the reaction tube 62 is depressurized to a predetermined vacuum degree and the heater 63 is brought into a uniform temperature state at a predetermined temperature. The process gas is caused to flow through the gas pipe 21 from 2 and the pressure and flow rate are controlled by the pressure reducing valve RG2 and the mass flow controller 4, respectively, and introduced into the reaction pipe 62 via the injector 61, and the inside of the reaction pipe 62 is predetermined. The wafer W is subjected to a heat treatment such as etching, CVD, or diffusion treatment while maintaining the pressure.

Gas leaks in the gas control equipment unit 7 from, for example, loose connections, and sparks are generated from the contacts of the electric parts such as the switch 35 and the relay 53 combined with the gas control equipment or the circuit. Even if a spark is generated due to a bad connection or a bad connection of the connector 26 of the tape heater 25, the electric components are separated from the atmosphere of the leaked gas, which may cause a gas explosion or fire. There is no. Further, in this way, the gas control device is provided with the housing 7 having the gas leakage prevention structure.
1 and the electric component unit 82 separately from this.
With the above configuration, it is not necessary to use an airtight structure or an explosion-proof structure for each electric component.

In the above, the electric component unit 82 is
The electric parts may be housed in a casing having an airtight structure, or gas sensors may be provided in both units 7 and 82 to shut off the power supply by the output of the gas sensors. And again without having to house all the gas control equipment in one housing,
It may be divided into a plurality of groups and each group may be stored in a storage unit such as a housing. Further, the electric parts do not necessarily have to be housed in the housing, and may be provided outside the housing of the gas control equipment unit.

The present invention may be applied not only to the heat treatment apparatus but also to an etching apparatus, an ion implantation apparatus, a plasma CVD apparatus, etc., and the object to be processed is not limited to a semiconductor wafer, but may be an LCD substrate or the like. Good.

[0026]

According to the present invention, a plurality of gas control devices are housed in a common storage part having a gas leakage prevention structure, and electric parts combined with the gas control device are arranged outside the storage part. Therefore, it is possible to prevent gas explosion and fire due to sparks of electric parts.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing an overview of a main part of an embodiment of the present invention.

FIG. 3 is a perspective view showing an overview of the overall configuration of an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a gas supply system of a conventional heat treatment apparatus.

[Explanation of symbols]

21 gas piping 25 heater 3 Pressure switch 36 circuit board 4 Mass flow controller 43 Signal processing unit 5 Shut-off valve 51 Air control unit 6 Heat treatment department 7 Gas control equipment unit 82 Electric component unit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-319291 (JP, A) Fukukaihei 5-46193 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/02 B01J 4/00 C30B 25/14

Claims (7)

(57) [Claims] 1. A plurality of gas control devices are connected to a gas processing unit via gas pipes, and the gas control devices are gas control devices.
Control of the main body and this gas control equipment main body or acquisition of detection signals
In Ru gas treatment device name and an electrical component for performing Eject and, arranging a plurality of gas control apparatus main body, housed in a common housing portion having a gas leakage prevention structure, the electrical components outside of the housing part A gas treatment device characterized by: 2. The gas processing apparatus according to claim 1, wherein the storage portion is formed of a housing having a hermetically sealed structure to which a ventilation pipe for ventilating the inside is connected. 3. A gas control device, Hui bets strike - includes a pressure switch for detecting the pressure by the resistor forming part of a down-bridge circuit, the electrical components arranged outside the housing part, setting the pressure detection value 3. The gas processing apparatus according to claim 1, further comprising a relay that outputs an alarm when the value is exceeded. 4. The gas control device includes a flow rate detector that detects a gas flow rate, a flow rate controller, and a signal processor that processes a detection signal of the flow sensor and outputs an operation signal to the flow controller. The gas processing apparatus according to claim 1, 2 or 3, wherein an electric component including a mass flow controller and arranged outside the housing includes the signal processing unit. 5. The gas control device includes a shutoff valve, and the electric component arranged outside the housing portion includes an air control unit for shutting off the shutoff valve with air. 5. The gas treatment device according to any one of 4 to 4. 6. The electric component is housed in an airtight case.
Claims 1, characterized in that that to the gas processing device according to any one of 5. 7. The gas treatment section is a heat treatment section for heat-treating an object carried into a reaction tube with a processing gas in a heating atmosphere. Gas treatment equipment.