JPH04297577A - Vacuum device - Google Patents

Abstract

PURPOSE:To prevent the inside of the vacuum device body from being abnormally pressurized even if a pressure detector for detecting the atm. pressure fails to operate by maintaining the pressure value in a vacuum chamber at a specified value or below when the pressure in the vacuum chamber attains the abnormal pressure exceeding the atm. pressure. CONSTITUTION:This vacuum device evacuates the inside of the vacuum chamber 1, into and from which a work can be fed and ejected, to a vacuum by a vacuum generating means including a vacuum piping 2 and a vacuum valve 3, pressurizes the vacuum chamber 1 after the evacuation to the atm. pressure by a pressurizing means including a pressurizing pump 9 and a control section 10, and has the control section 10 which detects the pressure in the vacuum chamber 1 at the time of this pressurization by the pressure detector 6 and stops the pressurization to the vacuum chamber 1 in accordance with the detection output of the pressure detector 6. The valve 4 is closed by the control section 10 in accordance with the operation of the pressure detector 8 when the internal pressure of the vacuum chamber 1 exceeds the atm. pressure, by which the pressure increase in the vacuum chamber 1 is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for creating a vacuum in a processing space, and in particular to a technique that is effective when used in sputtering processing in the manufacture of semiconductor devices.

0002

2. Description of the Related Art In sputtering, plasma CVD, SEM (scanning electron microscopy), etc., it is necessary to create a vacuum atmosphere in which the object to be processed is installed, and a vacuum device is used for this purpose. FIG. 3 is a sectional view showing an example of a conventional vacuum device.

A vacuum pipe 2 is connected to the box-shaped vacuum chamber 1, and the vacuum pipe 2 is provided with a vacuum valve 3 for maintaining a vacuum state. Further, a gas pipe 5 is connected via a valve 4, and a pressure detector 6 is further connected to detect when the pressure within the vacuum chamber 1 reaches atmospheric pressure. The output of this pressure detector 6 is applied to a control section (not shown) and is used as detection information associated with pressurization control. In addition, an opening/closing opening 7 is provided for loading/unloading objects to be processed such as wafers.

In operation, first, the vacuum valve 3 is closed and purge gas (nitrogen gas) is introduced from the gas pipe 5, and when the pressure detector 6 generates an output signal, that is, when atmospheric pressure is reached, the valve 4 is closed. . Here, the opening/closing port 7 is opened, the object to be processed is carried in through this opening/closing port 7, and the opening/closing port 7 is closed. Next, the vacuum valve 3 is opened, the gas in the vacuum chamber 1 is drawn from the vacuum piping 2 by a vacuum pump, the vacuum chamber 1 is brought to a predetermined degree of vacuum, and a process such as sputtering is performed, or another process is performed using an undisclosed conveying means. The workpiece a is transported to a vacuum chamber. When the process is completed, the vacuum valve 3 is closed and the valve 4 is opened, and purge gas is introduced into the vacuum chamber 1 until the pressure detector 6 generates a detection signal. When the pressure detector 6 generates an output signal, that is, when atmospheric pressure is reached, the valve 4 is closed, the opening/closing port 7 is opened, and the object to be processed is carried out of the main body.

By the way, the present inventor has studied the damage caused by pressure to a vacuum device due to failure of a pressure detector attached to the vacuum device.

[0006] The following are the techniques studied by the present inventors, and the outline thereof is as follows.

[0007] That is, when carrying in/out the workpiece, the pressure inside the vacuum chamber 1 is brought to atmospheric pressure, but whether or not atmospheric pressure has been reached is determined by
The determination is made based on the detected value of the pressure detector 6, and the valve 4 is controlled to close when the detected value outputs a value equivalent to the set pressure.

[0008]

[Problems to be Solved by the Invention] However, in the vacuum apparatus that performs pressure control using a pressure detector as described above,
If an abnormality such as a failure occurs in the pressure detector, gas exceeding the specified value may be introduced into the vacuum equipment, and if the pressure limit of the vacuum equipment is exceeded, there is a risk of an accident such as rupture. was discovered by the present inventor.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a technique that can prevent the inside of a vacuum apparatus from being abnormally pressurized even when a pressure detector does not operate.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

[Means for Solving the Problems] Among the inventions disclosed in this application, a brief overview of typical inventions will be as follows.
It is as follows.

[0012] Namely, a vacuum chamber into which a workpiece can be carried in/out, a vacuum generating means for evacuating the vacuum chamber, a pressurizing means for pressurizing the vacuum chamber to atmospheric pressure, and a vacuum generating means for evacuating the vacuum chamber. A vacuum device comprising a pressure detector for detecting the pressure in a room, and a control means for stopping pressurization of the vacuum chamber based on the detection output of the pressure detector, the vacuum device being separate from the pressure detector. , a safety means is provided to maintain the internal pressure of the vacuum chamber at a constant value when it exceeds atmospheric pressure.

[0013]

[Operation] According to the above-mentioned means, if the pressure detector that detects atmospheric pressure fails, even if pressure exceeding atmospheric pressure is applied to the vacuum chamber, the pressure in the vacuum chamber is stopped before reaching the burst pressure. This prevents the pressure inside the vacuum chamber from rising above a certain level by stopping or leaking. Therefore, it is possible to protect the vacuum chamber from excessive pressure and prevent destruction.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing an embodiment of a vacuum apparatus according to the present invention. Note that in FIG. 1, the same reference numerals are used for the same parts as in FIG. 3, so redundant explanation will be omitted here.

As shown in FIG. 1, a second pressure detector 8 is attached to the gas pipe 5 immediately in front of the valve 4. The operating pressure of this pressure detector 8 is set to the upper limit of the allowable pressure for the vacuum chamber 1 to be damaged by pressure. Detection signals from the pressure detectors 8 and 6 are sent to the control unit 10, and the opening and closing of the valve 4 is controlled based on the detected contents. In addition, the control unit 10
An alarm 11 is connected to the pressure detector 6 for notifying the failure of the pressure detector 6 with an alarm sound or the like.

In the above configuration, when the inside of the vacuum chamber 1 is brought to atmospheric pressure, the control section 10 operates according to the manufacturing program, closes the vacuum valve 3, and opens the valve 4. The pressure inside the vacuum chamber 1 gradually increases from the vacuum state, and when the detected value of the pressure detector 6 reaches atmospheric pressure, the control section 10 closes the valve 4.

However, if the pressure detector 6 is out of order,
Excessive gas pressure is applied within the vacuum chamber 1 during the pressurization process, and in the worst case, the vacuum chamber 1 will be damaged by pressure. However,
According to this embodiment, since the pressure detector 8 is provided, if the pressure is such that the pressure detector 8 would damage the vacuum chamber 1, the pressure detector 8 sends a detection signal to the control section 10. Based on the detection signal from the pressure detector 8, the control unit 10 opens the valve 4 and prohibits the operation of bringing the vacuum chamber 1 to atmospheric pressure. This prevents accidents that may damage the vacuum chamber 1 from occurring. Further, when the pressure detector 8 is activated, the control unit 10 activates the alarm 11 to notify the operator of the abnormality.

FIG. 2 is a system diagram showing another embodiment of the vacuum apparatus according to the present invention. In FIG. 2, the same reference numerals are used for the same parts as in FIG. 1, so redundant explanation will be omitted here.

This embodiment is characterized in that a check valve 12 is provided in the vacuum chamber 1 instead of the pressure detector 8. In this embodiment, when the vacuum chamber 1 reaches a certain pressure value due to pressurization, the check valve 12 opens to prevent the pressure within the vacuum chamber 1 from becoming abnormally high. In this embodiment, since the operation of opening the valve 4 is not performed automatically, knowing the operation of the check valve 12,
Valve 4 will be closed manually.

[0020] Above, the invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist thereof. Needless to say.

For example, in the embodiment described above, the pressure detector 8 is attached to the gas pipe, but it may also be attached to the vacuum chamber 1, and when a certain pressure value is reached, a detection signal is emitted. The detector may be structured to continuously detect pressure values. In this case, the acquired detection signal is compared with a comparison value set in advance by the control unit 10 to determine a pressure increase.

[0022]

[Effects of the Invention] Among the inventions disclosed in this application, the effects obtained by the typical inventions are briefly explained as follows.
It is as follows.

In other words, a vacuum chamber into which objects to be processed can be carried in/out, a vacuum generating means for evacuating the vacuum chamber, a pressurizing means for pressurizing the vacuum chamber to atmospheric pressure, and a vacuum chamber for evacuating the vacuum chamber. A vacuum device comprising a pressure detector for detecting the pressure inside the chamber, and a control means for stopping pressurization of the vacuum chamber based on the detection output of the pressure detector, Since a safety measure is provided to maintain a constant value when atmospheric pressure is exceeded, even if the pressure detector that detects atmospheric pressure fails, it is possible to prevent the vacuum chamber from being destroyed due to abnormal pressurization.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of a vacuum apparatus according to the present invention.

FIG. 2 is a system diagram showing another embodiment of the vacuum apparatus according to the present invention.

FIG. 3 is a system diagram showing a conventional vacuum device.

[Explanation of symbols]

1 Vacuum chamber 2 Vacuum piping 3 Vacuum valve 4 Valve 5 Gas piping 6 Pressure detector 7 Opening/closing opening 8 Pressure detector 10 Control section 11 Alarm 12 Check valve

Claims (4)

[Claims] 1. A vacuum chamber into which a workpiece can be carried in/out, a vacuum generating means for evacuating the vacuum chamber, a pressurizing means for pressurizing the vacuum chamber to atmospheric pressure, and a A vacuum device comprising a pressure detector for detecting the pressure in a room, and a control means for stopping pressurization of the vacuum chamber based on the detection output of the pressure detector, the vacuum device being separate from the pressure detector. . A vacuum apparatus, characterized in that a safety means is provided to maintain the internal pressure of the vacuum chamber at a constant value when it exceeds atmospheric pressure. 2. The safety means includes a pressure detector that detects the arrival of a pressure value below the burst pressure of the vacuum chamber, and a control that stops pressurizing the vacuum chamber based on the detected value of the pressure detector. The vacuum device according to claim 1, further comprising means. 3. The vacuum apparatus according to claim 1, wherein the safety means is a leak means that operates at a pressure value below the burst pressure of the vacuum chamber. 4. The safety means includes an alarm means that issues an alarm when the internal pressure of the vacuum chamber exceeds atmospheric pressure and detects a pressure value set below the burst pressure of the vacuum chamber. The vacuum device according to claim 1.