JP2002364702A - Vibration removing device and semiconductor manufacturing device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration removing device that removes a disturbance and eliminates characteristic dispersion of each air spring. SOLUTION: The vibration removing device has the air spring 2, a servo valve 3 for controlling pressure in the air spring, a pressure sensor 4 for detecting the pressure in the air spring, a vibration-removing table 1 supported by the air spring, and a displacement sensor 6 for detecting displacement of the vibration-removing table, and suppresses displacement and vibration of the vibration-removing table. A disturbance applied to the air spring is estimated from an input signal u to the servo valve, a detection signal p from the pressure sensor and a detection signal x from the displacement sensor, and the servo valve is controlled so as to suppress the disturbance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator used in a precision instrument equipped with a positioning device such as an XY stage, for example, a semiconductor manufacturing apparatus, and more particularly to a vibration isolator using an air spring as an actuator.

[0002]

2. Description of the Related Art With the increase in precision of precision instruments such as electron microscopes and semiconductor manufacturing equipment, there has been a demand for higher performance of precision vibration isolator equipped with them. In particular, in a semiconductor manufacturing apparatus, in order to perform appropriate and rapid exposure, a vibration isolator for eliminating vibration transmitted from the outside such as installation floor vibration as much as possible is required. This is because, in the semiconductor manufacturing apparatus, when exposing a semiconductor wafer, the XY stage for exposure must be in a completely stopped state. Also, the XY stage for exposure is characterized by an intermittent operation called step and repeat,
The repeated step operation excites the vibration of the vibration isolation table itself. Therefore, it is required for the vibration damping device to achieve a good balance between vibration damping performance against external vibration and vibration damping performance against vibration generated by the operation of the mounted device itself.

In response to such a demand, a so-called active type anti-vibration apparatus has been put into practical use, in which vibration of the anti-vibration table is detected by a vibration sensor and the anti-vibration table is driven by an actuator according to the detection signal. I have. The active anti-vibration device enables balanced realization of anti-vibration performance and anti-vibration performance, which is difficult with a passive anti-vibration device including only a support mechanism having spring and damper characteristics. In an active type vibration damping device, air is generally used as an actuator. This is because the air spring can easily generate a thrust sufficient to support a heavy object such as a semiconductor manufacturing apparatus main body. Also, by using an air spring, the natural frequency of the vibration isolator can be set to a low frequency of about several Hz, and sufficient vibration isolation performance against external vibration can be ensured.

[0004]

The anti-vibration table is supported by a plurality of air springs arranged substantially symmetrically with respect to the center of gravity. These air springs have a problem that variations in individual characteristics are so large that they cannot be ignored, and this characteristic difference causes deterioration of the performance of the vibration damping device.
The damping force applied from the air spring to the vibration isolation table is determined by multiplying the pressure of the air spring by the pressure receiving area. It is impossible to equalize the pressure receiving area with high accuracy due to manufacturing and the structure of the air spring. Therefore, it is inevitable that the vibration damping force varies in each air spring supporting the vibration isolation table. The pressure of the air spring is controlled by a servo valve (air valve). Servovalves are known to have non-linearities such as non-linearity and hysteresis, and this is a factor that causes inappropriate pressure fluctuation of the air spring. Further, since the flow rate of air in the piping system changes rapidly with the operation of the servo valve, the supply pressure to the servo valve fluctuates, and the pressure of the air spring fluctuates. Variations in the vibration damping force and inappropriate pressure fluctuations in each air spring act as disturbances to the vibration isolator, and thus have the problem of significantly degrading the performance of the vibration isolator.

[0005] A typical control system of a vibration isolator using an air spring is disclosed in Japanese Patent Application Laid-Open No. 7-83276. In this publication, a method of controlling the pressure of each air spring by negatively feeding back the vibration of the vibration isolation table in consideration of the arrangement of each air spring with respect to the center of gravity of the vibration isolation table is proposed. However, this publication assumes that there is no characteristic variation among the air springs. Actually, the disturbance described above is applied to the vibration damping device, so that the control method disclosed in the publication cannot be operated ideally. That is, there is an inconvenience that performance degradation of the vibration isolation device cannot be avoided.

The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a vibration isolator which eliminates disturbance and completely eliminates characteristic variations of each air spring.

[0007]

In order to achieve the above object, an anti-vibration apparatus according to the present invention comprises an air spring, a servo valve for controlling the pressure of the air spring, and a pressure for detecting the pressure of the air spring. A sensor, a vibration isolation table supported by the air spring, and a displacement sensor that detects a displacement of the vibration isolation table, wherein the vibration isolation device suppresses displacement and vibration of the vibration isolation table, Estimating a disturbance applied to the air spring from an input signal to the servo valve, a detection signal of the pressure sensor, and a detection signal of the displacement sensor, controlling the servo valve so as to suppress the disturbance. I do. Here, the estimated disturbance is a fluctuation of the internal pressure of the air spring based on a characteristic uncertain element of the air spring, such as the non-linearity of the servo valve, the variation of the air spring, and the influence of the supply / exhaust system. The fluctuation of the force acting on the vibration isolation table from the air spring and the like are combined. Further, a semiconductor manufacturing apparatus according to the present invention includes the above-described vibration isolator.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vibration isolator according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration of an anti-vibration apparatus according to one embodiment of the present invention. The anti-vibration table 1 is levitated and supported from the installation floor by an air spring 2. Normally, the vibration isolation table 1 is supported by a plurality of air springs arranged substantially symmetrically with respect to the center of gravity. The vibration isolator according to the present invention suitably controls the pressure in each air spring regardless of the number of air springs. Therefore, FIG. 1 shows only one air spring 2, but when a plurality of air springs are used, each air spring has the same configuration as that of FIG.

The air spring 2 is provided with a servo valve 3 for controlling the pressure inside the air spring 2 and a pressure sensor 4 for detecting the internal pressure. The acceleration sensor 5 and the displacement sensor 6 are mounted near the air spring 2, and the acceleration sensor 5 detects a vibration generated in the vibration isolation table 1, and the displacement sensor 6 detects a displacement of the vibration isolation table 1. The pressure compensating means 7 determines an input signal to the servo valve 3 according to each detection signal of the pressure sensor 4 and the displacement sensor 6. The servo valve 3 is driven via a power amplifier 8 by a signal generated by the pressure compensating means 7.

The function of the air spring 2 as an actuator is to control the internal pressure to suppress the vibration generated in the vibration isolation table 1 and to keep the height of the vibration isolation table 1 constant. Specifically, the vibration of the vibration isolation table 1 is detected by a vibration sensor such as the acceleration sensor 5 and the pressure of the air spring 2 is controlled in accordance with the detection signal. However, the vibration is quickly damped. Further, in order to keep the height of the vibration isolation table 1 constant, the height of the vibration isolation table 1 is detected by the displacement sensor 6 and the air spring 2 is moved so that the height coincides with a predetermined height. Controlling pressure. The height of the vibration isolation table 1 is equivalent to the displacement of the vibration isolation table 1,
The displacement is detected by the displacement sensor 6.

In order to realize such a function, it is necessary to appropriately control the pressure of the air spring 2 to apply a desired force to the vibration isolation table 1. However, generally, the air spring 2
It is difficult to control the pressure properly because there are many uncertainties in the characteristics. The following items are listed as uncertain factors.

First, it is difficult to completely control the pressure receiving area where the air spring 2 contacts the vibration isolation table 1. With a plurality of air springs used to support the vibration isolation table, it is impossible to equalize the pressure receiving areas with high accuracy in terms of manufacturing and the structure of the air spring. Since the force acting on the vibration isolation table is determined by multiplying the pressure of the air spring by the pressure receiving area, the force varies due to the difference in the pressure receiving area.

Next, the non-linearity of the servo valve 3 is mentioned. It is known that the servo valve 3 has nonlinearities such as non-linearity, hysteresis, and dead zone. Even if the detection signals of the acceleration sensor 5 and the displacement sensor 6 are fed back to the servo valve 3 to form a linear control system, there is a problem that the control system does not operate as designed because the servo valve 3 has nonlinearity. is there. This is the cause of inappropriate pressure fluctuation.

The change in the supply pressure to the servo valve 3 is shown. The servo valve 3 receives a supply of high-pressure air from a compressed air supply source such as a compressor, and compresses the depressurized air through a throttle mechanism inside the servo valve 3 to an air spring 2.
And exhaust unnecessary air. Usually, a mechanism for keeping the pressure constant is provided to suppress the fluctuation of the supply pressure. However, since the flow rate of air in the piping system fluctuates with the operation of the servo valve 3, the supply pressure is strictly kept constant. It is difficult. That is, the pressure of the air spring 2 fluctuates due to the fluctuation of the supply pressure. Such factors cause variations in the force acting on the vibration isolation table and fluctuations in the pressure of the air spring, which act as disturbances to the vibration isolation device, and thus significantly degrade the performance of the vibration isolation device. Was.

The anti-vibration device according to the present invention treats the above-mentioned uncertain element as a disturbance applied to the air spring 2, and receives an input signal to the servo valve 3 and the pressure sensor 4 and the displacement sensor 6.
, A disturbance is estimated from the detection signal, and the servo valve 3 is driven so as to cancel the disturbance.
The pressure compensating means 7 estimates the disturbance and generates an input signal of the servo valve 3 so as to cancel the disturbance.

FIG. 2 is a block diagram showing the operation of disturbance estimation by the pressure compensating means 7. The pressure p of the air spring 2 is a function of the input signal u to the servo valve, the displacement x of the vibration isolator 1 and the disturbance d. K is a gain function of the servo valve 3 and indicates a transfer characteristic of the input signal u up to the amount of air flowing into or out of the air spring 2. G ₁ represents the dynamic characteristics of the air spring 2, the pressure of the air in equilibrium temperature, determined by such a volume. G ₂ indicates the effect of the displacement x on the pressure p. G ₂ is mainly a function of the pressure receiving area of the air spring 2. The product of the displacement x and the pressure receiving area is the air spring 2
Is equivalent to a change in the volume of the air spring 2 and a change in the volume of air in the air spring 2. G is a dynamic characteristic from the pressure p to the displacement x, and indicates a characteristic of the motion of the vibration isolation table 1. G has to consider the 6 degrees of freedom movement of the anti-vibration table 1,
Accurate modeling is difficult. The disturbance d shows an uncertain characteristic of the air spring 2.

Since the transfer functions K, G ₁ and G ₂ are known from the mechanical or operating conditions of the vibration isolator, the disturbance d can be calculated from these transfer functions, the input signal u, the pressure p and the displacement x. Since the displacement x is detected by the displacement sensor 6, the disturbance d can be obtained even if the transfer function G that is difficult to model is unknown. The calculation formula is shown in formula (1).

[0018]

(Equation 1) If the servo valve 3 is driven so as to cancel out the disturbance d calculated by the equation (1), the disturbance d can be eliminated from the air spring 2 and a desired pressure can be generated. However,
Since the transfer functions K, G ₁ and G ₂ have model errors, and the pressure p and the displacement x contain observation noise, the influence of these error factors is removed by applying a noise removal filter g / (s + g). I do. Here, s indicates a Laplace operator, and g indicates a cutoff frequency of the filter. The estimated disturbance caused by the operation of the noise removal filter is defined as _{de sti} . The estimated disturbance _{de sti} is obtained by equation (2).

[0019]

(Equation 2) FIG. 3 is a block diagram showing disturbance cancellation by feedback of the estimated disturbance _{de sti} . In the pressure compensating means 7, an input signal u to the servo valve 3 is generated according to the equation (3) so that the estimated disturbance _{de sti} is fed back to cancel the disturbance d.

[0020]

(Equation 3) As a result, a desired pressure can be generated in the air spring 2 by completely eliminating characteristic uncertainties of the air spring 2. In the equation (3), u _ref is a signal applied to the servo valve 3 for damping the vibration of the vibration isolation table 1 and controlling the height to be constant. According to the present invention, since a desired pressure corresponding to _uref can be generated in the air spring 2, it is possible to provide a high-performance anti-vibration apparatus that eliminates the influence of disturbance.

The semiconductor manufacturing apparatus having the vibration damping device according to the present invention can be suitably implemented in various types of semiconductor manufacturing apparatuses, regardless of an exposure system such as a sequential exposure system or a scanning exposure system.

<Embodiment of Semiconductor Production System> Next, an embodiment of a production system for semiconductor devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.) will be described. In this method, maintenance services such as troubleshooting, periodic maintenance, and software provision of a manufacturing apparatus installed in a semiconductor manufacturing factory are performed using a computer network outside the manufacturing factory.

FIG. 4 shows the whole system cut out from a certain angle. In the figure, reference numeral 101 denotes a business establishment of a vendor (apparatus supply maker) that provides a semiconductor device manufacturing apparatus. Examples of manufacturing equipment include semiconductor manufacturing equipment for various processes used in semiconductor manufacturing factories, for example, pre-processing equipment (lithography equipment such as exposure equipment, resist processing equipment, etching equipment, heat treatment equipment, film formation equipment, planarization). Equipment) and post-process equipment (assembly equipment, inspection equipment, etc.). In the business office 101, a host management system 10 for providing a maintenance database of manufacturing equipment
8. It has a plurality of operation terminal computers 110 and a local area network (LAN) 109 connecting these to construct an intranet. Host management system 10
Reference numeral 8 includes a gateway for connecting the LAN 109 to the Internet 105, which is an external network of the business office, and a security function for restricting external access.

On the other hand, reference numerals 102 to 104 denote manufacturing factories of a semiconductor device maker as a user of the manufacturing apparatus. The manufacturing factories 102 to 104 may be factories belonging to different manufacturers or factories belonging to the same manufacturer (for example, a factory for a pre-process, a factory for a post-process, etc.). In each of the factories 102 to 104, a plurality of manufacturing apparatuses 106 and a local area network (LAN) 111 connecting them to construct an intranet are connected.
And a host management system 107 as a monitoring device for monitoring the operation status of each manufacturing apparatus 106. Host management system 1 provided in each factory 102 to 104
Reference numeral 07 includes a gateway for connecting the LAN 111 in each factory to the Internet 105 which is an external network of the factory. As a result, access from the LAN 111 of each factory to the host management system 108 on the vendor 101 side via the Internet 105 is possible, and only users limited by the security function of the host management system 108 are permitted to access. Specifically, each manufacturing device 106 is connected via the Internet 105.
In addition to notifying the vendor of the status information indicating the operation status of the device (for example, the symptom of the manufacturing apparatus in which the trouble has occurred), the response information corresponding to the notification (for example, information indicating a method of coping with the trouble, countermeasures) Software and data) as well as maintenance information such as the latest software and help information from the vendor. A communication protocol (TCP / IP) generally used on the Internet is used for data communication between each of the factories 102 to 104 and the vendor 101 and data communication with the LAN 111 in each of the factories. In addition, instead of using the Internet as an external network outside the factory,
It is also possible to use a high-security dedicated line network (such as ISDN) without access from a third party. Further, the host management system is not limited to the one provided by the vendor, and a user may construct a database and place it on an external network, and permit access from a plurality of factories of the user to the database.

FIG. 5 is a conceptual diagram showing the entire system of the present embodiment cut out from another angle than that of FIG.
In the above example, a plurality of user factories each having a manufacturing device and a management system of a vendor of the manufacturing device are connected via an external network, and the production management of each factory and at least one device are connected via the external network. The data of the manufacturing apparatus was communicated. On the other hand, in this example, a factory equipped with manufacturing equipment of a plurality of vendors is connected to a management system of each of the plurality of manufacturing equipments via an external network outside the factory, and maintenance information of each manufacturing equipment is stored. It is for data communication. In the figure, reference numeral 201 denotes a manufacturing factory of a manufacturing apparatus user (semiconductor device maker), and a manufacturing apparatus for performing various processes is provided on a manufacturing line of the factory. Has been introduced. Note that in FIG.
Although only one is depicted in FIG. 1, a plurality of factories are similarly networked. Each device in the factory is LAN2
The host management system 205 manages the operation of the production line.
On the other hand, each business establishment of a vendor (apparatus maker) such as an exposure apparatus maker 210, a resist processing apparatus maker 220, and a film forming apparatus maker 230 has a host management system 211, 221 for performing remote maintenance of the supplied apparatus. 2
31 comprising a maintenance database and an external network gateway as described above. Host management system 20 for managing each device in the user's manufacturing factory
5 and a vendor management system 211, 221,
231 is connected to the external network 200 via the Internet or a dedicated line network. In this system, if a trouble occurs in any of a series of manufacturing equipment in the manufacturing line, the operation of the manufacturing line is stopped, but remote maintenance is performed from the vendor of the troubled equipment via the Internet 200. As a result, quick response is possible, and downtime of the production line can be minimized.

Each of the manufacturing apparatuses installed in the semiconductor manufacturing factory includes a display, a network interface, and a computer that executes network access software and apparatus operation software stored in a storage device. The storage device is a built-in memory, a hard disk, a network file server, or the like. The network access software includes a dedicated or general-purpose web browser, and provides, for example, a screen user interface as shown in FIG. 6 on a display. The operator who manages the manufacturing equipment in each factory refers to the screen and refers to the manufacturing equipment model (401), serial number (402), trouble subject (403), date of occurrence (404), urgency (405),
Information such as a symptom (406), a coping method (407), and a progress (408) is input to input items on the screen. The input information is transmitted to the maintenance database via the Internet, and the resulting appropriate maintenance information is returned from the maintenance database and presented on the display. In addition, the user interface provided by the web browser further realizes a hyperlink function (410 to 412) as shown in the figure, so that the operator can access more detailed information of each item or use the software library provided by the vendor for the manufacturing apparatus. The latest version of software to be extracted can be extracted, and an operation guide (help information) can be extracted for reference by a factory operator. Here, the maintenance information provided by the maintenance database includes information on the characteristic uncertain element of the air spring described above, and the software library estimates the characteristic uncertain element (disturbance) of the air spring. We also provide the latest software to achieve

Next, a manufacturing process of a semiconductor device using the above-described production system will be described. FIG. 7 shows a flow of the whole semiconductor device manufacturing process. In step 1 (circuit design), the circuit of the semiconductor device is designed. Step 2 is a process for making a mask on the basis of the circuit pattern design. Step 3
In (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and step 4
This is a process of forming a semiconductor chip using the wafer produced by the above-described process, and includes an assembly process such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7). The pre-process and the post-process are performed in separate dedicated factories, and maintenance is performed for each of these factories by the above-described remote maintenance system. Further, information for production management and apparatus maintenance is also communicated between the pre-process factory and the post-process factory via the Internet or a dedicated line network.

FIG. 8 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), one of the semiconductor manufacturing apparatuses described above is used.
One of the exposure apparatuses prints and exposes the circuit pattern of the mask on the wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. Step 19
In (resist removal), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. Since the manufacturing equipment used in each process is maintained by the remote maintenance system described above, troubles can be prevented beforehand, and if troubles occur, quick recovery is possible. Productivity can be improved.

[0029]

As described above, according to the present invention,
Appropriate control of the air spring pressure can be achieved by eliminating characteristic uncertainties of the air spring. Disturbances such as pressure receiving area variation, servo valve nonlinearity, and supply pressure fluctuation are estimated from the input signal to the servo valve and the detection signals of the pressure sensor and the displacement sensor, and the servo valve is driven so as to cancel the disturbance. Therefore, a desired pressure can be generated in the air spring. That is, according to the present invention, it is possible to provide a vibration isolation device capable of suitably controlling the vibration damping force applied to the vibration isolation table, and a highly accurate semiconductor manufacturing apparatus having the vibration isolation device.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a preferred embodiment of a vibration isolator according to the present invention.

FIG. 2 is a block diagram showing a disturbance estimating means according to the present invention.

FIG. 3 is a block diagram showing a disturbance removing unit according to the present invention.

FIG. 4 is a conceptual view of a semiconductor device production system as viewed from a certain angle.

FIG. 5 is a conceptual diagram of a semiconductor device production system viewed from another angle.

FIG. 6 is a specific example of a user interface.

FIG. 7 is a diagram illustrating a flow of a device manufacturing process.

FIG. 8 is a diagram illustrating a wafer process.

[Explanation of symbols]

1: vibration isolation table, 2: air spring, 3: servo valve, 4: pressure sensor, 5: acceleration sensor, 6: displacement sensor, 7: pressure compensating means, 8: power amplifier.

Claims (10)

[Claims] An air spring; a servo valve for controlling a pressure of the air spring; a pressure sensor for detecting a pressure of the air spring; a vibration isolator supported by the air spring; A vibration sensor that has a displacement sensor that detects displacement, and suppresses displacement and vibration of the vibration isolation table, wherein the input signal to the servo valve, the detection signal of the pressure sensor, and the detection signal of the displacement sensor are used. An anti-vibration device characterized by estimating a disturbance applied to the air spring and controlling the servo valve so as to suppress the disturbance. 2. The method according to claim 1, wherein the estimated disturbance is a pressure fluctuation inside the air spring based on a characteristic uncertainty of the air spring and a fluctuation of a force acting on the vibration isolation table from the air spring. 3. The vibration isolator according to claim 1. 3. A semiconductor manufacturing apparatus having the vibration isolation device according to claim 1. 4. The semiconductor manufacturing apparatus according to claim 3, further comprising a display, a network interface, and a computer for executing network software, and performing data communication of maintenance information of the semiconductor manufacturing apparatus via a computer network. Semiconductor manufacturing equipment that made it possible. 5. The network software includes a user interface on the display connected to an external network of a factory where the semiconductor manufacturing apparatus is installed and for accessing a maintenance database provided by a vendor or a user of the semiconductor manufacturing apparatus. 5. The apparatus according to claim 4, wherein the apparatus provides information from the database via the external network. 6. A step of installing a group of manufacturing apparatuses for various processes including the semiconductor manufacturing apparatus according to claim 3 in a semiconductor manufacturing factory, and a plurality of processes using the group of manufacturing apparatuses. Manufacturing a semiconductor device by using the method. 7. A step of connecting the group of manufacturing apparatuses via a local area network, and data communication between at least one of the group of manufacturing apparatuses between the local area network and an external network outside the semiconductor manufacturing plant. 7. The method of claim 6, further comprising the step of: 8. A semiconductor manufacturing apparatus which accesses a database provided by a vendor or a user of the semiconductor manufacturing apparatus via the external network to obtain maintenance information of the manufacturing apparatus by data communication, or obtains semiconductor manufacturing equipment different from the semiconductor manufacturing factory. The method according to claim 7, wherein data is communicated with a factory via the external network to control production. 9. A group of manufacturing apparatuses for various processes including the semiconductor manufacturing apparatus according to any one of claims 3 to 5, a local area network connecting the group of manufacturing apparatuses,
A semiconductor manufacturing plant having a gateway for allowing access from the local area network to an external network outside the factory, and enabling data communication of information on at least one of the manufacturing apparatus groups. 10. The semiconductor device according to claim 3, which is installed in a semiconductor manufacturing plant.
6. The maintenance method for a semiconductor manufacturing apparatus according to any one of claims 1 to 5, wherein a vendor or a user of the semiconductor manufacturing apparatus provides a maintenance database connected to an external network of a semiconductor manufacturing plant; Having a step of permitting access to the maintenance database from within the manufacturing factory via the external network, and a step of transmitting maintenance information stored in the maintenance database to the semiconductor manufacturing factory via the external network. A method for maintaining a semiconductor manufacturing apparatus, comprising: