CRYOPUMP SYSTEM

Abstract

A cryopump system includes a temperature measurement unit configured to measure temperatures of a first stage part and a second stage part of a cryopump, respectively, a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature and a controller configured to gradually increase a motor rotational speed of a cooler of the cryopump whenever the temperature of the second stage part reaches the predetermined second reference temperature.

Description

TECHNICAL FIELD

The present disclosure relates to a cryopump system.

BACKGROUND

Cryogenic cooling is widely used in industrial fields such as semiconductor manufacturing and testing. Herein, cryogenic temperatures refer to temperatures below −200° C. A cooling process to achieve cryogenic temperatures is performed typically using a compressor, a condenser, an expander, and an evaporator in which a refrigerant evaporates to create a cryogenic environment.

In relation to technology for creating a cryogenic environment, Korean Patent Laid-open Publication No. 2020-0079062 discloses an ultra-cold cooler.

To create a cryogenic environment, GM (Gifford-McMahon) coolers, which are coolers for high-vacuum cryopumps, are mainly used. Such a cooler for cryopump operates with a motor at its maximum rpm when a temperature of the cryopump initially drops from room temperature to 20K. After the temperature of the cryopump reaches 20K, the motor of the cooler operates at around 50 to 60 rpm.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The present disclosure is conceived to provide a cryopump system that measures a temperature of a second stage part among a first stage part and the second stage part of a cryopump and monitors whether the temperature of the second stage part reaches a predetermined second reference temperature.

Also, the present disclosure is conceived to provide a cryopump system that gradually increases a motor rotational speed of a cooler in a cryopump whenever a temperature of a second stage part reaches a predetermined second reference temperature.

The problems to be solved by the present disclosure are not limited to the above-described problems. There may be other problems to be solved by the present disclosure.

Means for Solving the Problems

According to an aspect of the present disclosure, a cryopump system includes a temperature measurement unit configured to measure temperatures of a first stage part and a second stage part of a cryopump, respectively, a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature and a controller configured to gradually increase a motor rotational speed of a cooler of the cryopump whenever the temperature of the second stage part reaches the predetermined second reference temperature.

According to an embodiment of the present disclosure, the monitoring unit monitors whether a temperature of the first stage part is maintained at a predetermined first reference temperature while a first heater configured to heat the first stage part is in an OFF state.

According to an embodiment of the present disclosure, the controller gradually increases the motor rotational speed of the cooler of the cryopump whenever the temperature of the first stage part is higher than the predetermined first reference temperature while the first heater is in the OFF state.

According to an embodiment of the present disclosure, an initial motor rotational speed of the cooler is in the range of from 40 rpm to 50 rpm, and the controller increases the motor rotational speed of the cooler to between 80 rpm and 90 rpm.

According to an embodiment of the present disclosure, the controller increases the motor rotational speed of the cooler by from 5 rpm to 10 rpm whenever the temperature of the second stage part reaches the predetermined second reference temperature.

According to an embodiment of the present disclosure, the predetermined second reference temperature is from 17K to 20K.

The above-described aspects are provided by way of illustration only and should not be construed as liming the present disclosure. Besides the above-described embodiments, there may be additional embodiments described in the accompanying drawings and the detailed description.

Effects of the Invention

According to any one of the above-described means for solving the problems of the present disclosure, it is possible to provide a cryopump system that measures a temperature of a second stage part among a first stage part and the second stage part of a cryopump and monitors whether the temperature of the second stage part reaches a predetermined second reference temperature.

Also, it is possible to provide a cryopump system that gradually increases a motor rotational speed of a cooler in a cryopump whenever a temperature of a second stage part reaches a predetermined second reference temperature and thus reduces power consumption of the cryopump.

Conventionally, a cooler operates with a motor at its maximum rpm when a temperature of a cryopump initially drops from room temperature to 20K. However, the present disclosure provides a cryopump system that does not operate a cooler with a motor at its maximum rpm in an initial stage, but reduces power consumption of the cryopump while maintaining performance of the cryopump by gradually increasing a motor rotational speed of the cooler with an increase in temperature caused by an increase in use time or amount of gas condensed.

The present disclosure provides a cryopump system that operates a cooler in a cryopump at a low motor rotational speed of 40 rpm in the initial stage and thus reduces power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a cryopump system according to an embodiment of the present disclosure.

FIG. 2A illustrates a table showing temperatures and cooling capacities of a first stage part and a second stage part depending on an increase in motor rotational speed of a cooler in a cryopump according to an embodiment of the present disclosure.

FIG. 2B illustrates a cooling capacity graph of the first stage part and the second stage part at all motor rotational speeds of the cooler of the cryopump according to an embodiment of the present disclosure.

FIG. 2C illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 50 RPM for the cooler of the cryopump according to an embodiment of the present disclosure.

FIG. 2D illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 70 RPM for the cooler of the cryopump according to an embodiment of the present disclosure.

FIG. 2E illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 90 RPM for the cooler of the cryopump according to an embodiment of the present disclosure.

FIG. 3 is a flowchart showing a method for gradually increasing the motor rotational speed of the cooler of the cryopump in the cryopump system according to an embodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that the present disclosure may be readily implemented by a person with ordinary skill in the art. However, it is to be noted that the present disclosure is not limited to the embodiments but can be embodied in various other ways. In drawings, parts irrelevant to the description are omitted for the simplicity of explanation, and like reference numerals denote like parts through the whole document.

Further, through the whole document, the term “connected to” or “coupled to” that is used to designate a connection or coupling of one element to another element includes both a case that an element is “directly connected or coupled to” another element and a case that an element is “electronically connected or coupled to” another element via still another element. Furthermore, the term “comprises or includes” and/or “comprising or including” used in the document means that one or more other components, steps, operation and/or existence or addition of elements are not excluded in addition to the described components, steps, operation and/or elements unless context dictates otherwise.

Through the whole document, the term “unit” includes a unit implemented by hardware, a unit implemented by software, and a unit implemented by both of them. One unit may be implemented by two or more pieces of hardware, and two or more units may be implemented by one piece of hardware.

Through the whole document, a part of an operation or function described as being carried out by a terminal or device may be carried out by a server connected to the terminal or device. Likewise, a part of an operation or function described as being carried out by a server may be carried out by a terminal or device connected to the server.

Hereinafter, the present disclosure will be explained in detail with reference to the accompanying configuration views or process flowcharts.

FIG. 1 illustrates an example of a cryopump system according to an embodiment of the present disclosure. Referring to FIG. 1, the cryopump system 100 may include a cryopump 110, a temperature measurement unit 120, a monitoring unit 130, and a controller 140.

The cryopump 110 may include a cooler 111, a first stage part 112, a first heater 113, a second stage part 114, and a second heater 115.

The cryopump 110 may use the cooler 111 in a cooling process to create a cryogenic environment by using a cooling principle that allows the first stage part 112 and the second stage part 114 to reciprocate within a cylinder and expand a helium (He) gas inside the cylinder. The cooler 111 of the cryopump 110 has a higher freezing capability as a motor rotational speed increases, and has a lower freezing capability as the motor rotational speed decreases.

In the cooling process, the cryopump 110 uses the first heater 113 to increase a temperature of the first stage part 112 and uses the second heater 115 to increase a temperature of the second stage part 114. This is to maintain the temperatures of the first stage part 112 and the second stage part 114.

The temperature measurement unit 120 may measure temperatures of the first stage part 112 and the second stage part 114, respectively, of the cryopump 110. For example, the temperature measurement unit 120 uses a first temperature sensor (in the first stage part, not shown) to measure a temperature of the first stage part 112 and uses a second temperature sensor (in the second stage part, not shown) to measure a temperature of the second stage part 114.

The monitoring unit 130 may monitor whether the temperature of the second stage part 114 reaches a predetermined second reference temperature T2. Herein, the predetermined second reference temperature T2 may be from 17K to 20K.

For example, when the cooler 111 of the cryopump 110 operates at an initial motor rotational speed of from 40 rpm to 50 rpm, the monitoring unit 130 may monitor whether the temperature of the second stage part 114 reaches the predetermined second reference temperature T2 ranging from 17K to 20K.

In general, the cryopump 110 is maintained at the lowest temperature when it starts operating in a cleaned state after a regeneration process, and as more gas is condensed inside the cryopump 110, the temperature of the second stage part 114 gradually increases. For example, when a processing gas is used or as a vacuum holding time increases, ice on an adsorption plate (baffle) of the first stage part 112 or on an adsorption plate (array) of the second stage part 114 increases in thickness and the temperature of the second stage part 114 increases. Therefore, the monitoring unit 130 may monitor whether the temperature of the second stage part 114 reaches the predetermined second reference temperature T2.

The monitoring unit 130 may monitor whether the temperature of the first stage part 112 is maintained at a predetermined first reference temperature while the first heater 113 configured to heat the first stage part 112 is in an OFF state. Herein, the predetermined first reference temperature may be in the range of from 50K to 100K.

The temperature of the first stage part 112 may be, for example, 35K as a minimum reach temperature, and the temperature of the first stage part 112 is maintained in the range of from 50K to 100K depending on the process by the first heater 113 under the control of the controller 140. Based on this, the monitoring unit 130 may monitor whether the temperature of the first stage part 112 is maintained at a predetermined first reference temperature T1.

The controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 whenever the controller 140 receives a monitoring result from the monitoring unit 130 when the temperature of the second stage part 114 reaches the predetermined second reference temperature T2 or when the temperature of the first stage part 112 is not maintained at the predetermined first reference temperature T1 while the first heater 113 configured to heat the first stage part 112 is in the OFF state.

In the cooling process, the controller 140 may operate the cryopump 110 based on the initial motor rotational speed of the cooler 111 of the cryopump 110. Herein, the initial motor rotational speed of the cooler 111 may be in the range of from 40 rpm to 50 rpm.

Since the controller 140 uses the initial motor rotational speed in the range of 40 rpm to 50 rpm instead of using a maximum motor rotational speed as the initial motor rotational speed as in the conventional manner, it is possible to reduce power consumption.

The controller 140 may gradually increase the motor rotational speed of the cooler 111 of the cryopump 110 whenever the temperature of the second stage part 114 reaches the predetermined second reference temperature T2. For example, the controller 140 may gradually increase the motor rotational speed of the cooler 111 to between 80 rpm and 90 rpm by increasing the motor rotational speed of the cooler 111 by from 5 rpm to 10 rpm whenever the temperature of the second stage part 114 reaches the predetermined second reference temperature T2.

It is assumed that the controller 140 operates the cooler 111 of the cryopump 110 at the initial motor rotational speed of 40 rpm after the regeneration process. Then, when the temperature of the second stage part 114 reaches the predetermined second reference temperature T2 once, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 50 rpm. Then, when the temperature of the second stage part 114 reaches the predetermined second reference temperature T2 twice, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 60 rpm. Thereafter, when the temperature of the second stage part 114 reaches the predetermined second reference temperature T2 three times, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 70 rpm. Through this process, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 to 90 rpm.

Accordingly, when the temperature of the second stage part 114 increases to reach the predetermined second reference temperature T2, the controller 140 gradually increases the motor rotational speed of the cooler 111 of the cryopump 110 to maintain the temperature of the second stage part 114 at the predetermined second reference temperature.

Whenever the temperature of the first stage part 112 is higher than the predetermined first reference temperature T1 while the first heater 113 is in the OFF state, the controller 140 gradually increases the motor rotational speed of the cooler 111 of the cryopump 110.

For example, the controller 140 needs to increase the temperature of the first stage part 112 to maintain the predetermined first reference temperature T1. Therefore, the controller 140 may use the first heater 113 to maintain the first stage part 112 at the predetermined first reference temperature T1.

Then, the monitoring unit 130 may monitor whether the first reference temperature T1 is maintained even when the first heater 113 is turned off as a load of cooling capacity increases during long-term use of the cryopump 110, and may gradually increase the motor rotational speed of the cooler 111 of the cryopump 110 when the temperature of the first stage part 112 is not maintained at the predetermined first reference temperature T1.

For example, when the temperature of the first stage part 112 is not maintained at the predetermined first reference temperature T1 once while the first heater 113 is in the OFF state, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 50 rpm. Then, when the temperature of the first stage part 112 is not maintained at the predetermined first reference temperature T1 twice while the first heater 113 configured to heat the first stage part 112 is in the OFF state after the first heater 113 is operated, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 60 rpm. Thereafter, when the temperature of the first stage part 112 is not maintained at the predetermined first reference temperature T1 three times while the first heater 113 configured to heat the first stage part 112 is in the OFF state after the first heater 113 is operated, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 by 10 rpm to 70 rpm. Through this process, the controller 140 may increase the motor rotational speed of the cooler 111 of the cryopump 110 to 90 rpm.

FIG. 2A illustrates a table showing temperatures and cooling capacities of the first stage part 112 and the second stage part 114 depending on an increase in motor rotational speed of the cooler 111 of the cryopump 110 according to an embodiment of the present disclosure, and FIG. 2B illustrates a cooling capacity graph 210 of the first stage part 112 and the second stage part 114 at all motor rotational speeds of the cooler 111 of the cryopump 110 according to an embodiment of the present disclosure.

Referring to FIG. 2A and FIG. 2B, a motor rotational speed 200 of the cooler 111 of the cryopump 110 is set to 40 rpm to operate the cryopump 110 in an initial stage of the cooling process. Conventionally, the maximum motor rotational speed is set as the motor rotational speed 200 of the cooler 111 of the cryopump 110 in the initial stage of the cooling process. However, according to the present disclosure, the motor rotational speed 200 is lower than in the conventional case, and, thus, it is possible to reduce power consumption of the motor.

It can be seen that when the motor rotational speed 200 of the cooler 111 of the cryopump 110 is changed from 40 rpm to 90 rpm, a cooling capacity of the first stage part 112 is increased from 75 W to 105 W, but a cooling capacity of the second stage part 114 is in the range of from 9 W to 10 W, with no significant changes observed. Therefore, it can be seen that the cryopump to which the cooling capacity of the second stage part 114 is important is not much changed in cooling performance even when the motor rotational speed 200 is gradually increased from 40 rpm. Accordingly, the control of the motor rotational speed of the cooler depending on temperature can be greatly affected by changes in temperature of the first stage part, which indicates that it is possible to operate the cooler at a low motor rotational speed in an initial stage of use after regeneration and also possible to reduce power consumption of the motor.

FIG. 2C illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 50 RPM for the cooler of the cryopump according to an embodiment of the present disclosure. FIG. 2D illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 70 RPM for the cooler of the cryopump according to an embodiment of the present disclosure. FIG. 2E illustrates a cooling capacity graph of the first stage part and the second stage part at a motor rotational speed of 90 RPM for the cooler of the cryopump according to an embodiment of the present disclosure.

Referring to FIG. 2C to FIG. 2E, in general, freezing capability may increase as the motor rotational speed 200 of the cooler 111 of the cryopump 110 increases, and may decrease as the motor rotational speed 200 of the cooler 111 of the cryopump 110 decreases. Also, when the motor rotational speed 200 of the cooler 111 of the cryopump 110 is increased to 50 rpm, 70 rpm, or 90 rpm, cooling capacities of the first stage part 112 and the second stage part 114, respectively, gradually move to the upper right, which indicates an improvement in cooling capability. Even when the cooler is operated at 40 rpm, the first stage part shows a performance of 80 W or more and the second stage part shows a performance of 9 W or more. Therefore, the exhaust performance of the cryopump is not affected.

Conventionally, when a temperature of the cryopump drops from room temperature to 20K in an initial process of the cryopump 110, the maximum motor rotational speed 200 is used to control the cooler 111 of the cryopump 110, and then, when the temperature of the cryopump 110 reaches 20K, the cooler 111 of the cryopump 110 is operated at a motor rotational speed in the range of from about 50 rpm to about 60 rpm.

However, according to the present disclosure, the cryopump 110 operates with a motor at from an initial motor rotational speed to a maximum motor rotational speed. Thus, it is possible to reduce power consumption.

FIG. 3 is a flowchart showing a method for gradually increasing the motor rotational speed of the cooler of the cryopump in the cryopump system according to an embodiment of the present disclosure. The method for gradually increasing the motor rotational speed of the cooler 111 of the cryopump 110 performed by the cryopump system 100 illustrated in FIG. 3 includes the processes time-sequentially performed according to the embodiment illustrated in FIG. 1 to FIG. 2C. Therefore, the descriptions of the processes may also be applied to the method for gradually increasing the motor rotational speed of the cooler 111 of the cryopump 110 performed by the cryopump system 100 according to the embodiment illustrated in FIG. 1 to FIG. 2C even though they are omitted hereinafter.

In a process S310, the cryopump system 100 may measure a temperature of the second stage part 114 among the first stage part 112 and the second stage part 114 of the cryopump 110.

In a process S320, the cryopump system 100 may monitor whether the temperature of the second stage part 114 reaches the predetermined second reference temperature T2. In a process S330, the cryopump system 100 may gradually increase a motor rotational speed of the cooler 111 of the cryopump 110 whenever the temperature of the second stage part 114 reaches the predetermined second reference temperature T2.

In the descriptions above, the processes S310 to S330 may be divided into additional processes or combined into fewer processes depending on an embodiment. In addition, some of the processes may be omitted and the sequence of the processes may be changed if necessary.

The method for gradually increasing the motor rotational speed of the cooler of the cryopump performed by the cryopump system as described above with reference to FIG. 1 to FIG. 3 can be implemented as a computer program stored in a medium to be executed by a computer or a storage medium including instructions executable by a computer. Also, the method for gradually increasing the motor rotational speed of the cooler of the cryopump performed by the cryopump system as described above with reference to FIG. 1 to FIG. 3 can be implemented as a computer program stored in a medium to be executed by a computer.

A computer-readable medium can be any usable medium which can be accessed by the computer and includes all volatile/non-volatile and removable/non-removable media. Further, the computer-readable medium may include computer storage media. The computer storage media include all volatile/non-volatile and removable/non-removable media embodied by a certain method or technology for storing information such as computer-readable instruction code, a data structure, a program module or other data.

The above description of the present disclosure is provided for the purpose of illustration, and it would be understood by a person with ordinary skill in the art that various changes and modifications may be made without changing technical conception and essential features of the present disclosure. Thus, it is clear that the above-described examples are illustrative in all aspects and do not limit the present disclosure. For example, each component described to be of a single type can be implemented in a distributed manner. Likewise, components described to be distributed can be implemented in a combined manner.

The scope of the present disclosure is defined by the following claims rather than by the detailed description of the embodiment. It shall be understood that all modifications and embodiments conceived from the meaning and scope of the claims and their equivalents are included in the scope of the present disclosure.

Claims

1. A cryopump system, comprising: a temperature measurement unit configured to measure temperatures of a first stage part and a second stage part of a cryopump, respectively;a monitoring unit configured to monitor whether the temperature of the second stage part reaches a predetermined second reference temperature; anda controller configured to gradually increase a motor rotational speed of a cooler of the cryopump whenever the temperature of the second stage part reaches the predetermined second reference temperature.

2. The cryopump system of claim 1, wherein the monitoring unit monitors whether a temperature of the first stage part is maintained at a predetermined first reference temperature while a first heater configured to heat the first stage part is in an OFF state.

3. The cryopump system of claim 2, wherein the controller gradually increases the motor rotational speed of the cooler of the cryopump whenever the temperature of the first stage part is higher than the predetermined first reference temperature while the first heater is in the OFF state.

4. The cryopump system of claim 1, wherein an initial motor rotational speed of the cooler is in the range of from 40 rpm to 50 rpm, andthe controller increases the motor rotational speed of the cooler to between 80 rpm and 90 rpm.

5. The cryopump system of claim 1, wherein the controller increases the motor rotational speed of the cooler by from 5 rpm to 10 rpm whenever the temperature of the second stage part reaches the predetermined second reference temperature.

6. The cryopump system of claim 1, wherein the predetermined second reference temperature is from 17K to 20K.