JP3399587B2 - Vacuum apparatus baking method and baking apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum apparatus baking method and a baking apparatus for a molecular beam crystal growth apparatus and the like.

[0002]

2. Description of the Related Art A vacuum device such as a molecular beam crystal growth (MBE) device breaks a vacuum regularly or suddenly to perform source charging and maintenance.
At that time, it is necessary to perform cleaning for removing the impurity gas adsorbed on the inner wall of the apparatus and various impurities attached during the operation.

For the cleaning, a heater is installed around or under the apparatus, a panel is assembled so as to surround the entire apparatus, and the apparatus is heated to about 200 ° C. and a vacuum is applied for about 100 hours to degas the apparatus. This is done and is called baking. The panel functions to reduce heat dissipation to the outside and facilitate heating of the device.

[0004]

During the baking, the apparatus may cause a leak failure mainly in the metal casket portion due to thermal stress caused by heating. In that case, the impurities infiltrate into the high-temperature device together with the air and are adsorbed. Therefore, if a leak occurs, maintenance or source charge is performed again and baking is performed again. that time,
The source that has adsorbed the impurities due to the leak is discarded.

The present invention relates to the baking of vacuum devices,
An object of the present invention is to provide a vacuum device baking method and a baking device capable of preventing impurities from entering the inside of the device even if a leak failure occurs in the device.

[0006]

In order to achieve the above object, in a vacuum apparatus baking method according to the present invention, a vacuum apparatus to be baked is surrounded by a panel with a heater disposed outside the vacuum apparatus, and the vacuum apparatus and the vacuum apparatus are combined with each other. The step of replacing the space between the panels with nitrogen, the step of exhausting the vacuum device with a vacuum pump, the step of heating the vacuum device with the heater after the nitrogen replacement, and the step of heating the space replaced with nitrogen with He. Is introduced to detect He leaking into the vacuum apparatus.

Further, the baking apparatus according to the present invention is provided on a panel surrounding a vacuum apparatus to be baked, an exhaust pump for exhausting the vacuum apparatus, a heater for heating the vacuum apparatus, and the panel. A nitrogen introduction port for introducing nitrogen into the inside thereof, a He introduction port provided in the panel for introducing He inside thereof, an exhaust port provided in the panel for letting out gas inside thereof, and the vacuum device. And a He detection device for detecting the presence of He in the inside. The vacuum device is a molecular beam crystal growth device.

[0008]

In the above-mentioned baking method, even if the vacuum device causes a leak failure, the invasion into the vacuum device is limited to nitrogen and He, and the invasion of impurities can be prevented. Furthermore, it is possible to know during the baking whether or not a leak failure has occurred by detecting the He. As a result, baking can be performed efficiently. Of course, when dealing with a leak failure, it is possible to prevent the intrusion of impurities as described later.

Further, the baking apparatus can carry out the baking method depending on its configuration.
Then, when the vacuum device is an MBE device, it is not necessary to discard the source.

[0010]

Embodiments of the present invention will be described below with reference to FIG. 1, which is a schematic perspective view of an embodiment of a baking apparatus.

In FIG. 1, 1 is a vacuum device (MBE device) for baking, 2 is a panel, 3 is a heater, 4 is a nitrogen inlet, 5 is an exhaust port, 6 is a He inlet, 7 is a He detector, Reference numeral 8 is a load lock device, 9 is an exhaust passage to an exhaust pump (not shown) of the MBE device 1, and 10 is an exhaust passage to an exhaust pump (not shown) of the load lock device 8.

The panel 2 is assembled during baking and surrounds the vacuum device 1. Except for baking, it is disassembled and does not disturb the use of the vacuum device 1. The heater 3 is for heating the vacuum device 1, and is arranged inside the panel 2 so as to come around the vacuum device 1, although only partly shown in the drawing.

The nitrogen introducing port 4 is a port for introducing nitrogen into the inside of the panel 2 in order to replace the space between the vacuum device 1 and the panel 2 with nitrogen, and is provided at one end upper part of the side panel of the panel 2. . The exhaust port 5 is a port through which gas inside the panel 2 flows out, and is provided in a lower portion that is a diagonal position with respect to the nitrogen introducing port 4. The above arrangement of the nitrogen inlet 4 and the exhaust outlet 5 makes the nitrogen substitution efficient because nitrogen is lighter than air.

The He introducing port 6 is a port for introducing He into the inside of the panel 2, and is provided at the lower ends of both ends of the side panel. The above-mentioned position of the He introduction port 6 efficiently disperses He into the space. The He detection device 7 is a vacuum device 1.
To detect the presence of He in the interior with high sensitivity,
Notify whether the vacuum device 1 has caused a leak failure during baking. If the He detection device is used when the leak failure detection of the vacuum device 1 is performed independently,
It can be applied to the e-detection device 7.

The inside of the vacuum device 1 is evacuated by a vacuum pump via an exhaust path 9. The load lock device 8 is used for loading a wafer into the vacuum device 1 or for unloading a wafer for which crystal growth has been completed. At the time of baking, a valve provided in a portion of the load lock device 8 leading to the vacuum device 1 side is closed. Has been. Since the load lock device is also baked at the time of baking, it is exhausted through the exhaust path 10 by the exhaust pump.

Baking of the vacuum device 1 by the above-mentioned baking device is performed as follows. That is, by assembling the panel 2, the vacuum device 1 is surrounded by the panel 2. The heater 3 is arranged inside the panel 2.

Nitrogen is introduced from the nitrogen inlet 4 at a rate of about 300 per minute.
The gas inside the panel 2 is exhausted from the exhaust port 5 using a fan, if necessary, through the exhaust port 5, and the space between the vacuum device 1 and the panel 2 is replaced with nitrogen.

A valve (not shown) on the vacuum device side of the load lock device 8 is closed, and the inside of the vacuum device 1 is exhausted by a vacuum pump via the exhaust path 9. Evacuate continuously until the panel is disassembled.

About 1 hour after the introduction of nitrogen is started, the heater 3 is energized, and the vacuum apparatus 1 is heated at about 200 ° C. for about 2 hours so as to be substantially constant.

After confirming that the vacuum device 1 has reached about 200 ° C., He is introduced from the He introduction port 6 at a flow rate of about 10 liters per minute for about 10 minutes.

Whether or not there is a leak defect in the vacuum device 1 is confirmed by the He detection device 7.

If there is no leak defect, baking is performed for a long time by heating in that state.

If there is a leak defect, the heater 3 is de-energized while continuing to introduce nitrogen, and the panel 2 is disassembled after the vacuum apparatus 1 has cooled sufficiently to room temperature. After that, without discarding the source in the vacuum apparatus 1, the defective leak point is corrected by, for example, retightening, and the subsequent operation is performed again.

When the baking for a long time is finished, the heater 3 is de-energized, the vacuum device 1 is cooled to room temperature, the panel 2 is disassembled, and the baking work is completed.

As can be understood from the above, according to the vacuum apparatus baking method and the baking apparatus of the present invention, even if a leak failure occurs in the vacuum apparatus, the invasion of impurities into the vacuum apparatus is prevented. Further, it is possible to detect whether or not there is a leak failure during baking, and it is possible to efficiently perform baking, and it is possible to prevent impurities from entering even when dealing with a leak failure. When the vacuum device is an MBE device, it is not necessary to discard the source when there is a leak defect.

[0026]

As described above, according to the present invention, regarding baking of a vacuum device, even if a leak defect occurs in the device, it is possible to prevent impurities from entering the inside of the device, and to check whether or not there is a leak defect during baking. There is provided a vacuum device baking method and a baking device capable of detecting impurities and preventing the intrusion of impurities even when dealing with a leak failure, thereby making it possible to perform baking efficiently, and In the case of the MBE device, there is an effect that it is not necessary to discard the source due to a leak defect.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of a baking apparatus.

[Explanation of symbols]

1 Vacuum equipment for baking (MBE equipment) 2 panels 3 heater 4 Nitrogen inlet 5 exhaust port 6 He inlet 7 He detector 8 load lock device 9 MBE device exhaust path 10 Load lock device exhaust path

Continuation of the front page (56) Reference JP-A-63-224214 (JP, A) JP-A-2-46726 (JP, A) JP-A-3-279680 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H01L 21/203 C23C 14/24

Claims (3)

(57) [Claims] 1. A surrounds the vacuum device of the baking object panel by placing a heater on the outside, a step of replacing the space between the vacuum device and the panel with nitrogen, evacuating the vacuum apparatus by the exhaust pump having the steps of, heating the vacuum system by the heater after the nitrogen substitution, by introducing He into the nitrogen-purged space, and a step of detecting a He leaking into the vacuum device A method for baking a vacuum device, characterized by: 2. A panel surrounding the vacuum device of the baking object, an exhaust pump for evacuating the vacuum apparatus, a heater for heating the vacuum system, nitrogen is introduced into the inside is provided on the panel and nitrogen inlet, is provided to the panel He of introducing He to the inside
An inlet, an outlet for discharging the inside of the gas provided to the panel, baking apparatus characterized by having a He detector for detecting the presence of He in the vacuum apparatus. 3. The baking apparatus according to claim 2, wherein the vacuum apparatus is a molecular beam crystal growth apparatus.