JP3163160B2 - Heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a annealing apparatus using the H ₂ gas being used very much in the semiconductor process.

[0002]

_2. Description of the Related Art In a semiconductor device process, there is an annealing step using H ₂ gas. In this annealing step, if O ₂ is contained in the aluminum deposited film for aluminum wiring generated on the wafer, the aluminum wire wired by the fine processing may be broken due to aging, leading to quality deterioration, This is a processing step for reducing and removing O ₂ by annealing with H ₂ gas before or after etching for fine processing of the aluminum film.
This treatment is performed at 400 to 500 ° C. in an H ₂ gas atmosphere.

FIG. 2 is a simplified sectional view showing the structure of an example of a conventional annealing apparatus. This conventional annealing apparatus has a reaction tube 3 for isolating the outside air from the inside and reacting the wafer 10.
When a heater 1 for heating the reaction tube 3, the soaking tube 2 to obtain a uniform heat distribution in the inner reaction tube 3, the boat 8 for loading the wafer 10, the reaction of H ₂ gas from the gas inlet pipe 6 A furnace port 4 for flowing into the tube 3, an elevating mechanism 9 for loading and unloading the boat 8 filled with the wafer 10 into and from the reaction tube 3, and an exhaust for discharging the processed H ₂ gas in the reaction tube 3. A tube 18 and a high voltage electrode 21 for applying a high voltage to blow a spark
And a hydrogen pilot line 22 that acts as a pilot with the spark
A hydrogen combustion pipe 26 for combusting H ₂ gas exhausted from the exhaust pipe 18 due to the seed fire, a combustion box 20 for accommodating the hydrogen combustion pipe 26, and an exhaust duct for constantly forcibly exhausting the atmosphere in the combustion box 20 25.

In order to prevent H ₂ gas leakage, a bellows 17 is used in the furnace port 4 to isolate the wafer from the outside air.
An elevating mechanism 9a for retracting the bellows 17 for sealing the reaction tube 3 and the bellows portion, and a wafer 10 mounted on the lower portion of the bellows 17 for loading and unloading the boat 8 loaded with. An elevating mechanism 9b loads and unloads the boat 8 into and from the reaction tube 3.

In the conventional annealing apparatus, the exhaust pipe 18
The H ₂ gas after the treatment is exhausted from the hydrogen combustion pipe 26 introduced into the combustion chamber 20,
The combustion process is performed in the hydrogen gas combustion unit 23 using the hydrogen seed line 22 ignited by the spark generated in step 1 as a fire.

[0006]

However, in the above-mentioned conventional example, the exhaust equipment in which H ₂ gas is constantly forcibly exhausted from the exhaust duct 25 during combustion in the hydrogen combustion part 23 in the combustion chamber 20 is abnormal. · If you stop a malfunction, rapidly depleted of oxygen in the combustion box 20, will be at length disappears flames from incomplete combustion, the risk of the H ₂ gas is stopped explosion becomes very high in the combustion box 20 There is a problem that.

[0007]

In order to solve the above-mentioned problems, the apparatus of the present invention comprises: a reaction tube 3 for reacting a wafer;
A heater 1 for heating the inside of the reaction tube 3;
In a heat treatment apparatus having a gas introduction pipe 6 through which H ₂ gas flows through , and an exhaust pipe 5 for exhausting the inside of the reaction pipe 3, a combustion chamber 20 for burning H ₂ gas after processing exhausted from the exhaust pipe 5 is provided.
In addition to an exhaust duct 25 that exhausts the atmosphere of the box 20, a damper mechanism 24 that is opened when the exhaust is stopped is mounted.

[0008]

With such a configuration, even if the exhaust of the exhaust duct 25 is stopped due to an abnormality or failure during the combustion of the H ₂ gas, the damper mechanism 24 is activated and opened, so that the H ₂ gas combustion is stopped. It will continue without stopping, and H ₂
The danger of gas explosion can be avoided.

[0009]

FIG. 1 is a simplified sectional view showing the structure of an embodiment of the apparatus according to the present invention. In FIG. 1, 3 is a reaction tube for isolating the inside from the outside air and performing a reaction process on the wafer 10, 1 is a heater for heating the inside of the reaction tube 3, 2 is a soaking tube for uniforming the heat distribution in the reaction tube 3, and 8 Is a boat for loading the wafer 10, and 4 is a reaction tube 3.
The inside of the reactor is evacuated, and H ₂ gas is supplied through the gas inlet tube 6 to the reaction tube 3.
Furnace port to flow into, 9 is boat 8 loaded with wafer 10
Is loaded into the reaction tube 3 and unloaded.

[0010] The flange of the reaction tube 3 constituting the furnace port 4 and the flange 2 of the exhaust cylinder 28 with a flange opposed thereto.
8A, and between the seal flange 13a and the flange 28B of the flanged exhaust tube 28 facing the reaction tube, double inner and outer O-rings 11 are inserted, respectively. The space between the O-rings 11 and 11 communicates with the evacuation device 14 via the evacuation pipe 7, and the elastic body 12 is provided between the seal flange 13 a and the base flange 13 b attached to the elevating mechanism 9. It is inserted.

A vacuum exhaust pipe 5 for evacuating the inside of the reaction tube 3 is connected to a flanged exhaust tube 28 constituting the furnace port 4, and a vacuum exhaust device 16 is connected to this via a valve 15. A hydrogen combustion pipe 26 connected to the evacuation pipe 5 via a valve 19 is introduced into the combustion chamber 20, and a high voltage electrode 21 for applying a high voltage to blow a spark is disposed in the combustion chamber 20. In addition, a hydrogen seed line 22 that is ignited by a spark generated at the high-voltage electrode 21 when H ₂ gas is supplied is drawn in.

An exhaust duct 25 for exhausting the internal atmosphere is vertically provided in the combustion chamber 20, and a gas processing facility for forcibly exhausting the exhaust gas is connected to the exhaust duct 25. Further, an automatic damper mechanism 24 is mounted on the combustion chamber 20, and when the gas processing and exhaust equipment is stopped due to abnormality or failure, the exhaust duct 25
A differential pressure switch 27 that sends an operation signal to the automatic damper mechanism 24 based on the differential pressure inside the exhaust duct 25 is provided in the exhaust duct 25.

In the above configuration, the hydrogen seed line 22
It was flushed with H ₂ gas, skip spark by applying a high voltage to the high voltage electrode 21 at the same time, to ignite the hydrogen species fire line 22. The H ₂ gas exhausted from the inside of the reaction tube 3 passes through a flanged exhaust tube 28 of the furnace port 4, a vacuum exhaust pipe 5, a valve 19 and a hydrogen combustion pipe 26, and is burned in a hydrogen gas combustion section 23. .

The atmosphere inside the combustion chamber 20 is forcibly exhausted from an exhaust duct 25 by a gas processing exhaust system. The differential pressure switch 27 provided in the exhaust duct 25 monitors the operation state of the gas processing exhaust equipment connected to the exhaust duct 25 as needed.

If the gas processing and exhaust equipment connected to the exhaust duct 25 stops due to some abnormality, the differential pressure switch 27 detects this and outputs an open signal to the automatic damper mechanism 24. The auto damper mechanism 24 is activated by this open signal to be in an open state, the atmosphere in the combustion chamber 20 is opened to the atmosphere, and the combustion of the H ₂ gas is continued without stopping, and the explosion due to the H ₂ gas Danger can be avoided.

In this embodiment, each double O-ring 11,
The space between the chambers 11 is evacuated by an evacuation unit 14
Each O-ring 1 is evacuated through
1 and 11, the force of squeezing it and the force of squashing by the elastic body 12 are applied, and these double O-rings 11, 1
Since the resultant 1 is sufficiently crushed by the resultant force, the pressure during the processing of the wafer 10 (the pressure in the reaction tube 3)
However, even at atmospheric pressure, a sufficient sealing property is ensured.

Therefore, in this embodiment, one of the bellows and the elevating mechanism used conventionally is not required, and the cost can be reduced. In addition, the structure of the furnace opening 4 is made complicated by evacuating the space between the double ring-shaped seals 11 provided in the furnace opening 4 without using bellows or the like. In addition, it is possible not only to minimize the amount of H ₂ gas leak and to easily perform a leak check in the reaction tube 3 but also to improve safety by reducing the amount of H ₂ gas leak. it can.

In the present invention, the exhaust duct 25
The automatic damper mechanism 24 only needs to be opened when the forced exhaust from the pump is stopped. Therefore, the present invention is not limited to the embodiment in which the automatic damper mechanism 24 is opened by the differential pressure switch 27. For example, the forced exhaust operation is monitored and the operation stop is performed. The automatic damper mechanism 24 may be configured to perform an opening operation upon detection.

[0019]

As described above, according to the present invention, even if the exhaust of the exhaust duct 25 stops due to an abnormality or failure during the combustion of the H ₂ gas, the damper mechanism 24 is operated and opened, so that the H ₂ gas is opened. Combustion will continue without stopping, and H ₂
The danger of gas explosion can be avoided.

[Brief description of the drawings]

FIG. 1 is a simplified sectional view showing the configuration of an embodiment of the device of the present invention.

FIG. 2 is a simplified sectional view showing a configuration of an example of a conventional annealing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater 2 Heat equalizing pipe 3 Reaction pipe 4 Furnace opening part 5 Vacuum exhaust pipe 6 Gas introduction pipe 7 Vacuum exhaust pipe 8 Boat 9 Elevating mechanism 10 Wafer 11 Ring seal 12 Elastic body 13a Seal flange 13b Base flange 14 Vacuum exhaust device 15 Valve 16 Vacuum Exhaust Device 20 Combustion Chamber 21 High Voltage Electrode 22 Hydrogen Seed Line 23 Hydrogen Gas Combustion Unit 24 Auto Damper Mechanism 25 Exhaust Duct 26 Hydrogen Combustion Pipe 27 Differential Pressure Switch 28 Flanged Exhaust Cylinder

Claims (1)

(57) [Claims] 1. A heat treatment apparatus having a reaction tube for reacting a wafer, a heater for heating the inside of the reaction tube, a gas introduction tube for flowing H ₂ gas into the reaction tube, and an exhaust tube for exhausting the inside of the reaction tube. A heat treatment apparatus comprising: a combustion box that burns H ₂ gas after processing exhausted from an exhaust pipe; and a damper mechanism that is opened when the exhaust is stopped, separately from an exhaust duct that exhausts the atmosphere of the box.