WO2011052675A1

WO2011052675A1 - Pump unit, vacuum device, and exhaust device for load lock chamber

Info

Publication number: WO2011052675A1
Application number: PCT/JP2010/069155
Authority: WO
Inventors: 敏生鈴木
Original assignee: 株式会社アルバック
Priority date: 2009-10-29
Filing date: 2010-10-28
Publication date: 2011-05-05
Also published as: JPWO2011052675A1; TW201139853A

Abstract

A pump unit is provided with pump mechanisms (21, 31, 41), motors (22, 32, 42), an inverter (23), a control unit (24) which controls the inverter (23) and monitors the power level of the motors (22, 32, 42), and a storage unit (25) which stores the control patterns used by the control unit (24) for the controlling operations thereof, wherein the control unit (24) controls the inverter (23) so that the operation mode thereof is a restrictive operation mode in which the motors (22, 32, 42) reduce the rotation speed while continuing to rotate. Said control is performed either when the motors (22, 32, 42) are operated at least at a power level that exceeds a prescribed upper limit power level for more than a prescribed upper limit time period, or when, within a prescribed time period, the motors (22, 32, 42) are operated at a power level exceeding a prescribed upper limit cumulative power level.

Description

Pump unit, load lock chamber exhaust device, and vacuum device

The present invention relates to a pump unit, an exhaust device for a load lock chamber, and a vacuum device, and more particularly to a technique that can be efficiently operated without applying an excessive load to the pump.
This application claims priority based on Japanese Patent Application No. 2009-249133 for which it applied on October 29, 2009, and uses the content here.

For example, as an example of a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus (FPD manufacturing apparatus), an apparatus in which a load lock chamber (load lock chamber) is provided adjacent to a process chamber (processing chamber) that performs a film forming process on a wafer. It has been known. The load lock chamber maintains the inside of the process chamber in a vacuum (vacuum state) when exchanging a wafer or the like between the process chamber and the outside of the semiconductor manufacturing apparatus or the FPD manufacturing apparatus.

Such a load lock chamber is connected to a vacuum pump (pump unit) for making a predetermined vacuum (vacuum pressure) in the chamber. When exchanging a wafer or the like between the load lock chamber and the process chamber, the internal space of the load lock chamber is isolated from the outside of the semiconductor manufacturing apparatus, and the internal pressure of the load lock chamber is set to a predetermined degree of vacuum by a vacuum pump. The wafer or the like is exchanged between the load lock chamber and the process chamber.

On the other hand, when exchanging a wafer or the like between the load lock chamber and the outside of the semiconductor manufacturing apparatus, the internal space of the load lock chamber is isolated from the process chamber and the internal pressure of the load lock chamber is returned to the atmospheric pressure. Thus, the wafer or the like is exchanged between the load lock chamber and the outside of the semiconductor manufacturing apparatus.

When reducing the load lock chamber so that the internal pressure of the load lock chamber in such an atmospheric pressure reaches a predetermined degree of vacuum, the state of the open / close valve connected between the load lock chamber and the vacuum pump is changed. After switching from the closed state to the open state, the load lock chamber is depressurized by a vacuum pump. At this time, when the open / close valve is switched from the closed state to the open state while the vacuum pump is being driven, the internal pressure of the vacuum pump suddenly increases from vacuum to atmospheric pressure. Thereby, the load resulting from the pressure difference which generate | occur | produces in a vacuum pump increases rapidly. For this reason, the output torque of the motor that is the drive source of the vacuum pump also increases rapidly.

If the output torque of the vacuum pump motor increases rapidly, the components of the vacuum pump may be damaged. For this reason, conventionally, a sensor for monitoring the rotational speed or power value of the motor is provided outside the vacuum pump (pump unit), and the monitoring signal detected by this sensor is provided to the control unit of the vacuum pump (pump unit). By inputting, the vacuum pump is controlled so that the load torque of the vacuum pump does not exceed a predetermined upper limit value.

JP 2004-003503 A JP 2003-155981 A

However, in the conventional vacuum pump (pump unit) as described above, a sensor for monitoring the rotational speed or power value of the motor, a driver for controlling the sensor, etc. are prepared as external devices for the vacuum pump. To the outside of the vacuum pump. For this reason, in addition to the vacuum pump, there is a problem in that it takes time and effort to provide a protective device for operating the vacuum pump within an appropriate range, and an installation space in which the protective device is installed.

The present invention has been made to solve the above-described problems, and provides a pump unit having a protection function for operating a vacuum pump within an appropriate range with a simple configuration, space-saving and low cost. For the purpose.

Another object of the present invention is to provide an exhaust device for a load lock chamber provided with the pump unit having the protection function.
Furthermore, this invention aims at providing the vacuum apparatus provided with the pump unit which has the said protection function.

In order to solve the above problems, the present invention provides the following pump unit.
That is, the pump unit according to the first aspect of the present invention includes a pump mechanism unit that sucks gas through an intake port and exhausts the sucked gas through an exhaust port, a motor unit that drives the pump mechanism unit, and the motor unit An inverter unit for controlling the power value supplied to the control unit, a control unit for controlling the inverter unit and monitoring a power value of the motor unit, and a storage unit for storing a control pattern used for control by the control unit; including. In the pump unit according to the first aspect of the present invention, the control unit is in a state exceeding at least a predetermined upper limit power value, and when the motor unit is operated over a predetermined upper limit time, Alternatively, when the motor unit is operated within a predetermined time that exceeds a predetermined upper limit integrated power value, the motor unit enters a suppression operation mode in which the rotation speed is reduced while maintaining the rotation state. In addition, the inverter unit is controlled.

In the pump unit according to the first aspect of the present invention, it is preferable that the control unit releases the suppression operation mode after a predetermined maintenance time has elapsed and controls the inverter unit so as to enter the normal operation mode. .
In the pump unit according to the first aspect of the present invention, the storage unit stores a plurality of different control patterns, and an optimal control pattern is selected according to the decompression body connected to the intake port. Is preferably selected by:
A load lock chamber exhaust apparatus according to a second aspect of the present invention includes the pump unit described above, and is provided side by side with a process chamber in a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus.
A vacuum device according to a third aspect of the present invention includes the pump unit described above.

According to the present invention, even if the operation state in the pump unit, the exhaust device of the load lock chamber to which the pump unit is applied, and the vacuum device are in an unsteady state due to unexpected gas leakage or the like, the pump There is no need to stop the unit, and no excessive load is applied to the pump unit for a long time. For this reason, it becomes possible to continue the operation of the pump unit within a predetermined power value range.

This makes it possible to efficiently operate equipment including the manufacturing apparatus without stopping production in the semiconductor manufacturing apparatus to which the pump unit is applied. Further, by preventing an excessive load from being applied to the pump unit, it becomes possible to increase the durability and life of the pump unit, which contributes to reducing the running cost of the vacuum equipment to which the pump unit of the present invention is applied. .

It is the schematic which shows one Embodiment of the pump unit of this invention. It is a graph explaining the control method of the pump unit of this invention. It is a graph explaining the control method of the pump unit of this invention. It is the schematic which shows the 1st modification of the pump unit of this invention. It is the schematic which shows the 2nd modification of the pump unit of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode of a pump unit, a load lock chamber exhaust apparatus, and a vacuum apparatus according to the present invention will be described below with reference to the drawings.
The technical scope of the present invention is not limited to the embodiments described below, and various modifications can be made without departing from the spirit of the present invention.
In the drawings used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.

FIG. 1 is a schematic diagram showing the configuration of a pump unit and a semiconductor manufacturing apparatus including the pump unit according to an embodiment of the present invention. For example, the semiconductor manufacturing apparatus 10 includes a process chamber 11 for processing a wafer or the like under vacuum, and a load lock chamber (load lock chamber, decompression body) 12 connected to the process chamber 11.
The process chamber 11 performs, for example, vacuum deposition processing or sputtering processing on the wafer. At this time, the inside of the process chamber 11 is depressurized to a vacuum.

When a wafer or the like is carried into the process chamber 11 configured as described above from the outside of the semiconductor manufacturing apparatus 10 or a wafer or the like is carried out from the process chamber 11 to the outside of the semiconductor manufacturing apparatus 10, the load lock chamber 12. Is used.

Gate valves

13 and 14 are provided between the process chamber 11 and the load lock chamber 12 and between the load lock chamber 12 and the outside (normal pressure space), respectively. The

gate valves

13 and 14 isolate the outside of the semiconductor manufacturing apparatus 10 and the internal space of the load lock chamber 12, and isolate the internal space of the load lock chamber 12 and the internal space of the process chamber 11. Accordingly, the pressures of the load lock chamber 12 and the process chamber 11 are not affected by the pressure fluctuations of the adjacent chambers by the

gate valves

13 and 14.

A pump unit 20 is connected to the load lock chamber 12 of the semiconductor manufacturing apparatus 10 via an on-off valve 16. The pump unit 20 depressurizes the interior of the load lock chamber 12 to create a vacuum space. Further, the load lock chamber 12 is communicated with an external space (outside air) of the semiconductor manufacturing apparatus 10 through an on-off valve 17.

The pump unit 20 includes a pump mechanism unit 21 that depressurizes the load lock chamber 13 and exhausts the internal gas, and a motor unit 22 for driving the pump mechanism unit 21 inside the housing 26. .
The pump mechanism 21 sucks in the gas present in the load lock chamber 13 through the on-off valve 16 and the intake port, and exhausts the gas sucked through the exhaust port.
The motor unit 22 is connected to the control unit 24 via the inverter unit 23. The control unit 24 is provided with a storage unit 25.

The motor unit 22 is composed of, for example, a brushless motor, specifically, a brushless DC motor or the like. Such a motor unit 22 is driven by the electric power supplied from the inverter unit 23. The inverter unit 23 adjusts the frequency of the drive current supplied to the motor unit 22 according to the control signal input from the control unit 24. Thereby, the inverter unit 23 controls the power value supplied to the motor unit 22. Accordingly, the rotation speed of the motor unit 22 is adjusted.

The inverter unit 23 includes, for example, a current detection sensor and a voltage detection sensor, and detects a power value supplied to the motor unit 22. Then, the inverter unit 23 outputs the detected value to the control unit 24. Based on this information (detection value), the control unit 24 controls the inverter unit 23, monitors the power value of the motor unit 22, and adjusts the operating state of the motor unit 22.

Specifically, the inverter unit 23 has a function of controlling power. In other words, the inverter unit 23 has a function of reducing the rotation of the motor unit 22 when the torque in the pump mechanism unit 21 is large.
The control unit 24 instructs the inverter unit 23 whether or not to enable the function of the inverter unit 23 and also instructs the inverter unit 23 about the power target value. Here, the electric power is indicated by “(power) = (current) × (voltage) = (torque) × (rotational frequency)”. In the pump, since the electric power changes according to the load, the inverter unit 23 controls the torque and the rotation frequency, that is, the voltage, the current, and the rotation frequency so that the electric power is smaller than the electric power instructed from the control unit 24. To do.

In the storage unit 25, a standard variation pattern of a detection value used for controlling the motor unit 22 determined in advance, a threshold value used for changing the power value when the detection value deviates from the variation pattern, and the like. Remembered. Such a fluctuation pattern or threshold value of the detected value is referred to from the control unit 24 as needed. That is, the storage unit 25 stores a control pattern used for control by the control unit 24.

In such a storage unit 25, a plurality of different control patterns are stored. Further, the control unit 24 selects an optimal control pattern from among a plurality of control patterns according to a load lock chamber (decompression body) connected to the intake port. When selecting an optimal control pattern in this way, a control pattern that can be used within the condition range of the pump characteristics (exhaust characteristics) used in the pump unit is selected.
Specifically, for example, the control unit 24 selects an optimal control pattern based on input information input by using an input device (not shown) connected to the control unit 24. As such input information, for example, information related to arithmetic conditions for converting the integrated power, setting information related to the control operation mode (for example, a threshold value of power value, duration, integrated power, etc. described later), control operation mode Examples include setting information related to continuation conditions (for example, duration, upper limit of power supply, etc.). The control operation mode means a normal operation mode and a suppression operation mode described later.

A specific method (control example) for controlling the power value in the pump unit of the present invention having the above-described configuration will be described with reference to FIGS.

(Control method based on a predetermined upper limit power value)
FIG. 2 is a graph showing changes in the power value supplied to the motor unit of the pump unit and changes in the internal pressure of the load lock chamber (vacuum vessel) accompanying the change in the power value.
PART (A) in FIG. 2 shows a change in which the internal pressure of the load lock chamber decreases from the atmospheric pressure toward a predetermined ultimate pressure as the gas existing in the load lock chamber is exhausted. First, at P _rmax that is atmospheric pressure, the power value is P _o1 , and when the exhaust of gas starts, the power value gradually increases. In the process of increasing the power value, at time t1, the power value reaches a threshold value _Po2 described later, and the power value further increases.

In the process of continuing the exhaust, the power value increases due to the compression work of the pump unit, and the power value reaches the maximum power value _Pomax at time t2. Thereafter, after the time t2 has elapsed, the compression work starts to decrease as the pressure decreases, and the power value decreases. In the process in which the power value is decreasing, at time t3, the power value reaches a threshold value _Po2 described later, and the power value further decreases. And finally at time t4, the internal pressure reaches the ultimate pressure _{P rmin,} also the smallest _{P Omin} power value.

The relationship between the power value and the pressure is determined by the shape and volume of the load lock chamber (vacuum vessel, decompression body), the exhaust performance of the pump unit, and the configuration of the exhaust pipe provided between them. That is, if the vacuum vessel, the pump unit, and the piping configuration are constant, the transition of the power value and the transition of the pressure in this configuration can be estimated.

The PART (B) in FIG. 2 shows the pressure of the vacuum vessel when some trouble occurs, for example, when a gas leak occurs due to maintenance work of the load lock chamber (vacuum vessel) or removal work of piping. This shows the change in the power value when the pressure does not decrease and the change in the internal pressure of the vacuum vessel.
Here, “gas leak” refers to a phenomenon in which gas cannot be sufficiently introduced between a high-pressure atmosphere and a low-pressure atmosphere, and gas is unexpectedly introduced into the vacuum vessel or vacuum pipe. means.
When a leak state occurs in this way, the amount of leak and the pumping capacity of the pump unit are balanced, and the power P _o3 and the pressure P _r3 become steady (constant). If such a leak state continues for a long time, power is wasted.

In the control method based on the predetermined upper limit power value in the embodiment of the present invention, the pump unit 20 is controlled as follows.
In such a leak state, the electric power P _o3 monitored by the inverter unit 23 is higher than the threshold value P _o2 . That is, the power _Po3 exceeds the upper limit power value defined in advance. In this way, the drive of the pump is continued in a state where the power exceeds the threshold value P _o2 , and when a predetermined time t5 to t6 elapses, the control unit 24 _{changes the} power value supplied to the motor unit 22 to the power P _o4. Then, control of the inverter unit 23 and the motor unit 22 is started. As a result, the operation state of the motor unit 22 is switched from the normal operation mode to the suppression operation mode.
That is, when the motor unit 22 is operated for a predetermined upper limit time in excess of a predetermined upper limit power value, the control unit 24 rotates the rotation speed while maintaining the motor unit 22 in a rotating state. The inverter unit 23 is controlled so as to be in the suppression operation mode in which
The above threshold _{P o2} is set to be larger than the power _{P o1} and _{P Omin.} In the actual production process, the control unit 24 controls the motor unit so that the power value supplied to the motor unit does not become the power _Po4 .
Moreover, in the actual production process in the manufacturing apparatus in which the pump unit of the present embodiment is used, the operation mode is set to the suppression operation mode (pressure P _o4 ) when the pump is operating normally (normal operation mode). In order to prevent switching, the control pattern is set so that the times t5 to t6 are longer than the above-described times tl to t3. Further, in this control pattern, a margin time is included in the times t5 to t6. Here, the margin time is a time set for maintaining the durability of the pump, and is a time necessary for avoiding malfunction. Such a margin time is appropriately set according to the use conditions of the manufacturing apparatus in which the pump unit is used.

As described above, after the operation state of the motor unit 22 is switched from the normal operation mode to the suppression operation mode and a predetermined time t6 to t7 (maintenance time) has elapsed, the control unit 24 determines that the operation state of the motor unit 22 is The inverter unit 23 is controlled to return to the original operation (normal operation mode) from the suppression operation mode.

(Control method based on integrated power value)
Next, a control method based on the integrated power value will be described. In the following description, the method described in FIG. 2 is omitted or simplified.
FIG. 3 is a graph showing a change in the power value supplied to the motor unit of the pump unit. FIG. 3 illustrates a control method of the pump unit when the motor unit 22 is operated within a predetermined time that exceeds a predetermined upper limit integrated power value.
In addition, the integrated power value while the pump is driven is calculated by the control unit 24 based on the power value monitored by the inverter unit 23 and the elapsed time. Further, the predetermined upper limit integrated power value is stored in the control unit 24 or the storage unit 25.

When a leak state occurs as shown in FIG. 2, the amount of leak and the pumping capacity of the pump unit are balanced, and the power P _o3 and the pressure P _r3 (see FIG. 2) become steady (constant). If such a leak state continues for a long time, power is wasted.

In the control method based on the integrated power value in the embodiment of the present invention, the pump unit 20 is controlled as follows.
In such a leak state, the driving of the pump is continued while the electric power exceeds the threshold value _Po2 in this way. As shown in PART (A) of FIG. 3, the integrated power value indicated by the symbol X increases with the operation time of the pump. When the integrated power value X increases as the predetermined time t5 to t6 elapses, it exceeds the predetermined integrated value (predetermined upper limit integrated power value) indicated by the product of the power threshold _Po2 and the time t5 to t6. The integrated power value X (the value indicated by the product of the power value monitored by the inverter unit 23 and the times t5 to t6) increases.

When the control unit 24 determines that the integrated power value X is larger than a predetermined integrated value, the control unit 24 uses the inverter unit 23 and the inverter unit 23 so that the power value supplied to the motor unit 22 _{becomes the} power _Po4. Control of the motor unit 22 is started. As a result, the operation state of the motor unit 22 is switched from the normal operation mode to the suppression operation mode.
That is, when the motor unit 22 is operated within a predetermined time that exceeds a predetermined upper limit integrated power value, the control unit 24 reduces the rotation speed while the motor unit 22 maintains the rotation state. The inverter unit 23 is controlled so as to be in the suppression operation mode.
As described above, in the control method shown in PART (A) of FIG. 3, even when the power value is temporarily smaller than the power threshold value _Po2 (see X1), the integrated power value X is It is continuously calculated, and it is continuously determined whether the integrated power value X is larger or smaller than a predetermined integrated value based on the power threshold value _Po2 . That is, even if the power value temporarily decreases, the operation state is determined based on the integrated power value, and an excessive load is prevented from being applied to the pump unit for a long time.

Further, as shown in PART (B) of FIG. 3, the pump unit 20 may be controlled based on the integrated power value.
PART (B) in FIG. 3 shows a state in which the pump is continuously driven while the power monitored by the inverter unit 23 exceeds the threshold value _Po2 . As shown in PART (B) in FIG. 3, the integrated power value indicated by the symbol Y increases with the operation time of the pump. When the integrated power value Y increases as the predetermined time t5 to t6 elapses, it exceeds the predetermined integrated value (predetermined upper limit integrated power value) indicated by the product of the power threshold _Po2 and the time t5 to t6. The integrated power value Y (the value indicated by the product of the power value monitored by the inverter unit 23 and the times t5 to t6) increases.

When the control unit 24 determines that the integrated power value Y is larger than a predetermined integrated value defined in advance, the control unit 24 uses the inverter unit 23 and the inverter unit 23 so that the power value supplied to the motor unit 22 _{becomes the} power _Po4. Control of the motor unit 22 is started. As a result, the operation state of the motor unit 22 is switched from the normal operation mode to the suppression operation mode.
That is, when the motor unit 22 is operated within a predetermined time that exceeds a predetermined upper limit integrated power value, the control unit 24 reduces the rotation speed while the motor unit 22 maintains the rotation state. The inverter unit 23 is controlled so as to be in the suppression operation mode.
Also in such a control method, the operating state is determined based on the integrated power value, and an excessive load is prevented from being applied to the pump unit for a long time.

In the present embodiment, the control method based on the integrated power value has been described as shown in FIG. 3, but the present invention is not limited to the above-described embodiment. For example, based on the average power value within a predetermined time calculated by the power value measured in the inverter unit 23 and the operation time, the control unit 24 changes the operation state of the motor unit 22 from the normal operation mode to the suppression operation mode. You may switch. Moreover, the control part 24 may switch the driving | running state of the motor part 22 as mentioned above using the electric power value weighted based on driving | operation time. Moreover, the control part 24 may switch the driving | running state of the motor part 22 as mentioned above using the value by which the electric power value was processed based on the arithmetic process generally known.

As described above, in the present embodiment, the operation state of the pump unit, the exhaust device of the load lock chamber to which the pump unit is applied, and the vacuum device are in an unsteady state due to an unexpected gas leak or the like. Even if it becomes, it is not necessary to stop the pump unit 20, and an excessive load is not given to the pump unit for a long time. For this reason, it becomes possible to continue the operation of the pump unit 20 within a predetermined power value range.

This makes it possible to efficiently operate the equipment including the manufacturing apparatus without stopping production in the semiconductor manufacturing apparatus to which the pump unit is applied. Further, by preventing an excessive load from being applied to the pump unit, it becomes possible to increase the durability and life of the pump unit, which contributes to reducing the running cost of the vacuum equipment to which the pump unit of the present invention is applied. .

In the above-described embodiment, the configuration including one pump mechanism unit and the motor unit has been described as an example of the pump unit 20, but the present invention is not limited to this structure. For example, as a first modification of the above embodiment, as shown in FIG. 4, a configuration in which two pump bodies including a pump mechanism unit 31 and a motor unit 32 are connected in series may be employed.
As a second modification of the above embodiment, as shown in FIG. 5, a configuration in which two pump bodies including a pump mechanism portion 41 and a motor portion 42 are connected in parallel may be employed.

In addition to the above configuration, a configuration in which three or more pump bodies including a pump mechanism unit and a motor unit are connected in series or in parallel may be employed. In the structure using the plurality of pump bodies, the specifications of the pumps may be different from each other.

The present invention can be widely applied to pump units, exhaust devices for load lock chambers, and vacuum devices.

DESCRIPTION OF SYMBOLS 10 Semiconductor manufacturing apparatus 11 Process chamber 12 Load lock chamber 20

Pump unit

21, 31, 41

Pump mechanism part

22, 32, 42 Motor part 23 Inverter part 24 Control part 25 Memory | storage part 26 Case

Claims

A pump unit,
A pump mechanism for sucking gas through the air inlet and exhausting the sucked gas through the air outlet;
A motor unit for driving the pump mechanism unit;
An inverter unit for controlling a power value supplied to the motor unit;
A control unit for controlling the inverter unit and monitoring a power value of the motor unit;
A storage unit for storing a control pattern used for control by the control unit;
Including
The control unit is specified in advance at least when the motor unit is operated beyond a predetermined upper limit time in a state exceeding a predetermined upper limit power value, or within a predetermined time. When the motor unit is operated exceeding the upper limit integrated power value, the inverter unit is controlled such that the motor unit enters a suppression operation mode in which the rotation speed is reduced while maintaining the rotation state. Pump unit to be used.
The pump unit according to claim 1,
The said control part cancels | releases the said suppression operation mode, after passing the maintenance time prescribed | regulated previously, and controls the said inverter part so that it may become a normal operation mode. The pump unit characterized by the above-mentioned.
The pump unit according to claim 1 or 2,
In the storage unit, a plurality of different control patterns are stored,
The pump unit, wherein an optimal control pattern is selected by the control unit in accordance with the decompression body connected to the intake port.
An exhaust device for a load lock chamber,
A pump unit according to any one of claims 1 to 3,
An exhaust device for a load lock chamber, which is provided in a process chamber in a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus.
A vacuum device,
A vacuum apparatus comprising the pump unit according to any one of claims 1 to 3.