Patent Publication Number: US-2022230840-A1

Title: Charged Particle Beam Device

Description:
TECHNICAL FIELD 
     The present invention relates to a charged particle beam device. 
     BACKGROUND ART 
     In the related art, a computer which is connected to an electron microscope serving as a charged particle beam device and which is used for controlling the electron microscope is usually used in a stand-alone form or used in a state of being connected to an intranet and not connected to an external network. However, in recent years, the need for connecting the computer connected to an electron microscope to an external computer via a network to transmit and receive data and the like is increasing. 
     For example, PTL 1 discloses a technique in which remote monitoring (for example, remote monitoring of an electron generation chip of an electron gun) of an electron microscope disposed on a client (customer) side is executed in a service server connected to the electron microscope via a network, the service to the client is improved, and the operation rate of the electron microscope is improved. 
     In addition, a system has begun to be used in which a computer connected to an electron microscope is connected to a network outside an intranet, so that various services can be enjoyed. In such a system, in the computer connected to an electron microscope, installation and update of security software and periodic update of an operating system (OS) are required. Therefore, in the computer, since opportunities for software other than control software for the electron microscope to operate increase, resource insufficiency in the computer may be concerned. 
     In the computer, it is difficult to grasp or predict, in advance, an amount of resources (a CPU, a DRAM, and the like) available in a computer by the software other than the control software for the electron microscope. Therefore, as a result of the operation of the software other than the control software, resources required for the operation of the control software cannot be allocated, and the operation of the control software may be unstable. In a system of the charged particle beam device such as the electron microscope, since a high-voltage power source or an electron beam is handled, the unstable control software needs to be avoided. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: JP-A-2003-36807 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The invention has been made in view of the above problems, and an object of the invention is to provide a charged particle beam device capable of reliably allocating resources of control software and realizing stable operation of the control software even when a computer for controlling the charged particle beam device is connected to an external computer. 
     Solution to Problem 
     In order to solve the above problems, a charged particle beam device according to the invention includes a charged particle beam device main body, a computer configured to control the charged particle beam device, including a CPU and a DRAM, and including software for controlling the charged particle beam device main body, a monitoring unit configured to monitor a resource usage status in the computer, an allocation availability determination unit configured to determine whether or not a resource for executing processing required by the software is allocatable in the computer according to a monitoring result of the monitoring unit, and a notification unit configured to notify, when the determination of the allocation availability determination unit is negative, information indicating that the determination is negative. 
     Advantageous Effect 
     According to the invention, a charged particle beam device capable of reliably allocating resources of control software and realizing stable operation of the control software even when a computer for controlling the charged particle beam device is connected to an external computer can be provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an overall configuration diagram illustrating an example of a configuration of a charged particle beam device according to a first embodiment. 
         FIG. 2  shows flowcharts illustrating examples of operations of the charged particle beam device according to the first embodiment. 
         FIG. 3  shows flowcharts illustrating other examples of the operations of the charged particle beam device according to the first embodiment. 
         FIG. 4  is an overall configuration diagram illustrating an example of a configuration of a charged particle beam device according to a second embodiment. 
         FIG. 5  is a schematic diagram illustrating a charged particle beam device according to a third embodiment. 
         FIG. 6  is a schematic diagram illustrating a charged particle beam device according to a fourth embodiment. 
         FIG. 7  is a schematic diagram illustrating a charged particle beam device according to a fifth embodiment. 
         FIG. 8  is a schematic diagram illustrating a charged particle beam device according to a sixth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments will be described with reference to accompanying drawings. In the accompanying drawings, functionally same elements may be donated by the same numbers. Although the accompanying drawings show embodiments and implementation examples in accordance with principles of the present disclosure, the drawings are shown for the understanding of the present disclosure and are not intended to limit the invention. Descriptions in this specification are merely exemplary, and are not intended to limit the scope of the claims or application of the present disclosure in any sense. 
     It is necessary to understand that the embodiments are described in sufficient detail for those skilled in the art to perform the present disclosure, but other implementations and aspects are possible, and the configuration and the structure can be changed and various elements can be replaced without departing from the scope and the spirit of the technical idea of the present disclosure. Therefore, the following description should not be construed as being limited to the embodiments. 
     First Embodiment 
     First, an example of a configuration of a charged particle beam device according to a first embodiment will be described with reference to  FIG. 1 . As shown in  FIG. 1 , the charged particle beam device includes a computer (a control terminal)  10 , a charged particle beam device main body  20 , and a monitor  30 . In  FIG. 1 , a hardware configuration and a software configuration of the computer  10  are illustrated together. 
     The computer  10  and the charged particle beam device main body  20  are connected by, for example, a cable L 1  for a local area network (hereinafter referred to as a LAN), and are configured to transmit and receive data and control signals to and from each other. In addition, the computer  10  and the monitor  30  are also connected by a monitor cable L 2 . Although not shown, the charged particle beam device main body  20  can include an electron gun unit that emits a charged particle beam from a charged particle source, a lens body unit that converges or deflects the charged particle beam, a sample support unit that holds a sample in a lens body, a detector unit that detects electrons when the sample is scanned, and a camera unit that detects electrons transmitted through the sample. The charged particle beam emitted from the electron gun unit is converged or deflected by the lens body unit, and is emitted onto the sample on the sample support unit. Information of the sample is visualized by using the detector unit or the camera unit depending on a purpose. As a visualization method, for example, a method for capturing as image data is used. Visualization information of the sample acquired from the charged particle beam device main body  20  and a graphical user interface (hereinafter, GUI) of device control software  101  are displayed on the monitor  30  connected to the computer  10 . 
     The computer  10  is a control terminal for controlling the charged particle beam device main body  20 . Specifically, the computer  10  includes, as the hardware configuration, a CPU  11 , a DRAM  12 , a ROM  13 , a hard disk drive (HDD)  14 , and interfaces (I/Fs)  15  to  18 . 
     The CPU  11  is an arithmetic processing unit that performs arithmetic control required for operations of the charged particle beam device main body  20 , and the operations include generation of control signals for controlling the charged particle beam device main body  20 , reception of signals and data from the charged particle beam device main body  20 , data processing and management, and the like. The DRAM  12  is a volatile memory device for temporarily storing various data generated in operations of the computer  10 . In addition, the ROM  13  is a non-volatile memory device that stores initial setting data and various programs. 
     The HDD  14  is a storage device that stores software (a computer program) including the device control software  101  and an operating system (OS)  105 . In addition, the HDD  14  can also be used as a storage device that stores image data of an image imaged by the charged particle beam device main body  20  and analysis data that is an analysis result of the image. The I/Fs  15  to  17  manage input and output of data between the charged particle beam device main body  20  and the CPU  11 , between the monitor  30  and the CPU  11 , and between an input unit (not shown) and the CPU  11 , via terminals T 1  and T 2 . In addition, the I/F  18  is connected to an external computer (not shown) or a server via a terminal T 3  and a network. It is needless to say that the computer  10  may additionally include a processor circuit or a storage device (not shown). 
     The computer  10  includes the device control software  101  and the OS  105 . The device control software  101  is software for controlling the charged particle beam device main body  20 . The OS  105  is basic software that controls the overall operation of the computer  10 . In addition, the computer  10  includes a resource monitoring unit  103 , an allocation availability determination unit  104 , and a notification unit  106 . The resource monitoring unit  103 , the allocation availability determination unit  104 , and the notification unit  106  may be realized by the OS  105  and software (not illustrated in  FIG. 1 ). 
     The resource monitoring unit  103  has a function of monitoring a usage rate of the CPU  11 , a usage amount of the DRAM  12 , and other computer resource usage status in cooperation with the OS  105 . The resource monitoring unit  103  may monitor both the usage rate of the CPU  11  and the usage amount of the DRAM  12  as a resource usage status, or may monitor only one of the usage rate of the CPU  11  and the usage amount of the DRAM  12 . In addition, operating statuses of processor circuits, storage devices, and the like other than the CPU  11  and DRAM  12  can also be monitored. 
     In addition, the allocation availability determination unit  104  determines whether or not resources for executing processing required by the device control software  101  can be allocated in the computer  10  (including the CPU  11 , the DRAM  12 , and the like) according to an output (a monitoring result) of the resource monitoring unit  103 . The notification unit  106  receives a determination result of the allocation availability determination unit  104  via the device control software  101 , and notifies a user by, for example, displaying the result on a screen of the monitor  30 . The notification method in the notification unit  106  is not limited to the display on the monitor  30 , and a means capable of notifying the user, such as a printer or voice, can be used. The plurality of notification methods may be used in combination. 
     Here, when the computer  10  is connected to only the charged particle beam device main body  20  and is not connected to an external computer (when the computer  10  is a stand-alone computer), substantially only the device control software  101  consumes the resources (the usage rate of the CPU  11  and the usage amount of the DRAM  12 ) in the computer  10 . Therefore, it is easy to predict the resource usage status in the computer  10 . However, the computer  10  of this embodiment is connected to an external computer via a network, and is capable of transmitting and receiving the image data imaged by the charged particle beam device main body  20  and other analysis data to and from an external computer, for example. 
     When data and the like is transmitted to and received from an external computer, the usage rate of the CPU  11  and the usage amount of the DRAM  12  by the OS  105  and communication software (not shown) increase. In addition, the OS  105  may be updated periodically or irregularly, and such an operation also unexpectedly increases the usage rate of the CPU  11  and the usage amount of the DRAM  12 . 
     Therefore, in the computer  10 , the resource monitoring unit  103  monitors the resource usage status including the usage rate of the CPU  11 , the usage amount of the DRAM  12 , and the like, and the allocation availability determination unit determines whether or not the resources required by the device control software  101  can be allocated according to the monitoring result. Accordingly, even when the computer  10  is connected to an external computer via a network and resources are consumed unexpectedly, an appropriate operation in the device control software  101  can be ensured. 
     Next, examples of operations related to resource monitoring and the like in the charged particle beam device according to the first embodiment will be described with reference to flowcharts of  FIG. 2 . 
     In step S 11 , the device control software  101  notifies the allocation availability determination unit  104  of a required amount of resources including a usage rate of the CPU and a usage amount of the DRAM and the like required for an own operation of the device control software  101 . 
     In the subsequent step S 12 , the resource monitoring unit  103  starts processing of monitoring the resource usage status (including the usage rate of the CPU  11  and the usage amount of the DRAM  12 ) in the computer  10 . The resource monitoring processing will be described in detail later. 
     Based on a monitoring result, whether or not resources for executing the processing required in the device control software  101  can be allocated in the computer  10  is determined. When it is determined that the resources can be allocated, step S 12  is continued, and when it is determined that the resources cannot be allocated, the process proceeds to step S 13 . 
     In step S 13 , when it is determined that the resources cannot be allocated, the allocation availability determination unit  104  generates interference information and notifies the device control software  101  of the interference information. The interference information may include at least whether or not the amount of resources required for operation can be allocated, a name (or ID) of a process executed by the device control software  101 , a usage rate of the CPU  11  of each process, a usage amount of the DRAM  12  of each process, and the like. The device control software  101  executes interference information notification processing according to the received interference information (step S 14 ). The interference information notification processing will be described in detail later. 
     The resource monitoring processing will be described in detail with reference to steps S 21  to S 25  shown in the center of  FIG. 2 . First, in step S 21 , the resource monitoring unit  103  sends, to the OS  105 , a query that inquires resource usage status of each process executed by the computer  10 . 
     In step S 22 , when receiving the query, the OS  105  confirms the resource usage status of each process and notifies (replies) the resource usage status of each process to the resource monitoring unit  103 . The resource monitoring unit  103  determines the resource usage status according to the received information, and transmits the resource usage status to the allocation availability determination unit  104 . 
     In step S 23 , the allocation availability determination unit  104  determines whether or not the amount of resources required for the operation of the device control software  101  can be allocated in the computer  10  according to the received data of the resource usage status. The allocation availability determination unit  104  calculates a remaining amount of resources based on the current resource usage status notified from the resource monitoring unit  103 , and compares the remaining amount of resources with the amount of resources required for the operation of the device control software  101 . According to a result of the comparison, whether or not the amount of resources can be allocated is determined. 
     When it is determined that the resources can be allocated, the process proceeds to step S 24 . When it is determined that the resources cannot be allocated, the resource monitoring processing (S 12 ) ends, and the process proceeds to step S 13  described above. 
     In step S 24 , whether or not a restriction of the amount of resources to be used by the device control software  101  is set is determined. When the restriction is set, the device control software  101  releases the restriction in step S 25 , then ends the resource monitoring processing, and the process proceeds to step S 13 . On the other hand, when it is determined that the amount of resources is not restricted, the resource monitoring processing ends, and the process proceeds to step S 13 . 
     Next, the interference information notification processing of step S 14  will be described in detail with reference to steps S 31  to S 33  shown on a right side of  FIG. 2 . In step S 31 , the device control software  101  notified of the interference information notifies the notification unit  106  of the interference information. In step S 32 , the device control software  101  restricts the amount of resources in the computer  10  to be used by the device control software  101  according to the interference information. For example, the amount of resources can be restricted by at least reducing a capacity of image data to be used for real-time display of an observation image by the charged particle beam device body  20  and reducing a procedure of image processing to be applied to the image data. An input of such a restriction can be performed by the user from an input unit (a keyboard, a mouse, or the like) of the computer  10  while confirming the display of the monitor  30 . In this case, the input unit functions as a restriction unit that restricts the usage amount of resources in the computer  10  to be used by the device control software  101  when the determination of the allocation availability determination unit  104  is negative. 
     Subsequently, in step S 33 , the notification unit  106  causes the monitor  108  to display the interference information. As a result, the user can grasp the amount of resources available for the device control software  101  and refer to the amount of resources at the time of the operation. 
       FIG. 3  shows flowcharts of other examples of the operations related to resource monitoring and the like in the charged particle beam device according to the first embodiment. In step S 24 , the presence or absence of the resource restriction is confirmed, and when there is a restriction, the restriction is released (step S 25 ), which is the same as  FIG. 2 . However, before the release, in step S 26 , the user confirms whether or not to release the resource restriction, and the resource restriction is released when the user selects to release the resource restriction. This point is a difference from  FIG. 2 . In step S 26 , it is possible to perform at least one of confirmation of a message and confirmation of a setting value related to the release. 
     As described above, according to the charged particle beam device of the first embodiment, the resources of the computer are monitored by the resource monitoring unit  103 , whether or not the resources can be allocated is determined by the allocation availability determination unit  104 , and when it is determined that the resources cannot be allocated, a notification of the result is issued. Therefore, even when the computer is connected to an external computer, the resources of the device control software can be reliably allocated, and the stable operation of the device control software can be realized. 
     Second Embodiment 
     Next, an example of a configuration of a charged particle beam device according to a second embodiment will be described with reference to  FIG. 4 . In  FIG. 4 , the same components as those of the configuration of the first embodiment ( FIG. 1 ) are denoted by the same reference numerals, and a repetitive description thereof will be omitted below. The device according to the second embodiment includes the computer  10  and a remote control terminal  40 . 
     The remote control terminal  40  includes remote control software  301  and the notification unit  106 , and is connected to the computer  10  via terminals T 5  and T 6  through the LAN (a cable L 3 ). By the operation of the remote control software  301 , the computer  10  can be remotely controlled by the remote control terminal  40 . The function of the notification unit  106  is the same as that of the notification unit  106  of the first embodiment. Other configurations of the computer  10  are the same as the configuration of the computer  10  of the first embodiment. The remote control terminal  40  is connected to the monitor  30  through the LAN (the cable L 2 ) via a terminal T 2 ′. The notification unit  106  transmits the interference information received from the allocation availability determination unit  104  via the remote control software  301  to the monitor  30  and causes the monitor  30  to display the interference information. 
     In  FIG. 4 , since the remote control terminal  40  is connected to the monitor  30 , the computer  10  is not connected to the monitor, but the computer  10  may be further connected to another monitor (not shown) different from the monitor  30 . 
     An operation of the device of the second embodiment is substantially the same as the operation of the first embodiment ( FIGS. 2 and 3 ). A difference is that when the interference information is notified from the allocation availability determination unit  104 , the interference information is notified to the notification unit  106  through the LAN (the cable L 3 ) via the remote control software  301  of the remote control terminal  40 . 
     In addition, in  FIG. 4 , the device control software  101  is controlled by the remote control software  301  existing in the remote control terminal  40 , but the remote control terminal  40  may acquire only GUI information of the computer  10  and display the GUI information on the monitor  30 , and the user may control the device control software  101  existing in the computer  10  based on the GUI information displayed on the monitor  30 . In this case, the notification unit  106  needs to exist in the computer  10 . According to the second embodiment, the same effect as that of the first embodiment can be exerted. In addition, the charged particle beam device main body  20  can be controlled from the remote control terminal  40  separated from the computer  10 . 
     Third Embodiment 
     A charged particle beam device according to a third embodiment will be described with reference to  FIG. 5 . An entire configuration of the charged particle beam device of the third embodiment can be the same as those of the embodiments described above, and thus a repetitive description thereof will be omitted. In the third embodiment, the operation when it is determined in the allocation availability determination unit  104  that the resources cannot be allocated, specifically, the operation for executing the resource restriction is different from those in the embodiments described above. This point will be described below with reference to  FIG. 5 . 
     When the allocation availability determination unit determines that the resources cannot be allocated, the notification unit  106  causes the monitor  30  to display a process list  401  shown in  FIG. 5 . This process list  401  is a list of names of processes (AAA to EEE) that are normally executed in the device control software  101 , and a process stop button  402  and an end button  403  are displayed below the process list  401 . Although not illustrated in  FIG. 5 , in order to clearly indicate that the resources are insufficient for the user, a message or the like indicating that the resources are insufficient may be displayed together on the monitor  30 . 
     The user views the process list displayed on the monitor  30 , designates a process that is to be stopped or may be stopped among the plurality of processes AAA to EEE via an input unit such as a mouse or a keyboard, and then presses the process stop button  402 . As a result, a part of the processes executed in the device control software  101  is stopped, thereby reducing the required resources, and the operation of the device control software  101  can be performed even under the resource insufficient condition. When the instruction to stop the process is completed, the end button  403  can be pressed to close the process list  401 . 
     As described above, according to the charged particle beam device of the third embodiment, the same effect as that of the first embodiment can be exerted. In addition, when the resources are insufficient, a certain process can be stopped by the selection of the user, so that the operation of the device control software adapted to the request of the user can be ensured. 
     Fourth Embodiment 
     A charged particle beam device according to a fourth embodiment will be described with reference to  FIG. 6 . An entire configuration of the charged particle beam device of the fourth embodiment can be the same as those of the embodiments described above, and thus a repetitive description thereof will be omitted. In the fourth embodiment, the operation when it is determined in the allocation availability determination unit  104  that the resources cannot be allocated, specifically, the operation for executing the resource restriction is different from those in the embodiments described above. 
     As shown in  FIG. 6 , in the fourth embodiment, when the allocation availability determination unit  104  determines that the resources can be allocated, the device control software  101  instructs a camera unit  501  of the charged particle beam device main body  20  to transmit an image size required for real-time image acquisition. The camera unit  501  transmits an image having the instructed image size to the device control software  101 . 
     On the other hand, when the allocation availability determination unit  104  determines that the resources cannot be allocated, the device control software  101  instructs the camera unit  501  to transmit an image having a size half of the image size required for the real-time image acquisition. The camera unit  501  transmits an image having the instructed image size to the device control software  101 . 
     As described above, the charged particle beam device of the fourth embodiment is configured to change the size of the image acquired from the camera unit  501  according to the determination result of whether or not the resources can be allocated. This makes it possible to continue the real-time image acquisition even when the amount of resources is restricted. 
     Fifth Embodiment 
     A charged particle beam device according to a fifth embodiment will be described with reference to  FIG. 7 . An entire configuration of the charged particle beam device of the fifth embodiment can be the same as those of the embodiments described above, and thus a repetitive description thereof will be omitted. In the fifth embodiment, the operation when it is determined in the allocation availability determination unit  104  that the resources cannot be allocated, specifically, the operation for executing the resource restriction is different from those in the embodiments described above. 
     When the allocation availability determination unit  140  determines that the resources cannot be allocated, the notification unit  106  causes the monitor  30  to display a resource amount restriction setting screen  601  shown in  FIG. 7 . This resource amount restriction setting screen  601  is a screen for notifying the user of a resource insufficient status and restricting, by selection of the user, the amount of resources to be used. This screen  601  includes a display unit  602  that displays an amount of resources that can be allocated for the device control software  101 , and an input unit  603  that allows the user to designate an amount of resources to be used by the device control software  101 . 
     As an example, the display unit  602  displays the amount of resources that can be allocated for the computer  10  with the amount of resources being separated into an available capacity in the DRAM  12  and a usage rate of the CPU  11 , which are examples of the amount of resources that can be allocated, and either one of the available capacity of the DRAM  12  and the usage rate of the CPU  11  may be used, or other indices may be used in addition to the available capacity in the DRAM  12  and the usage rate of the CPU  11 . 
     In addition, the user can input the capacity to be used in the DRAM  12  and the usage rate of the CPU  11  via the input unit  603 . The user can confirm display contents of the display unit  602 , and can input, for example, for the capacity used in the DRAM  12  and the usage rate of the CPU  11 , numerical values smaller than numerical values displayed on the display unit  602 . As a result, the amount of resources used by the device control software  101  can be freely restricted in a status where the resources are insufficient. 
     Sixth Embodiment 
     A charged particle beam device according to a sixth embodiment will be described with reference to  FIG. 8 . An entire configuration of the charged particle beam device of the sixth embodiment can be the same as those of the embodiments described above, and thus a repetitive description thereof will be omitted. In the sixth embodiment, the operation when it is determined in the allocation availability determination unit  104  that the resources cannot be allocated, specifically, the operation for executing the resource restriction is different from those in the embodiments described above. 
     When the allocation availability determination unit  140  determines that the resources cannot be allocated, the notification unit  106  causes the monitor  30  to display a display area setting screen  701  shown in  FIG. 8 . This display area setting screen  701  is a screen for notifying the user of a resource insufficient status, restricting a display area of an imaged observation image by the selection of the user, and reducing the amount of resources required by the device control software  101 . 
     Specifically, this resource restriction setting screen  701  includes a first display section  702  and a second display section  703 . The first display section  702  is a section on which an image size (a display area) of a currently set observation image and a capturing interval are displayed. In addition, the second display section  703  is a section on which an image size of an observation image that enables the device control software  101  to operate, which is determined according to the amount of resources available by the device control software  101  and a capturing interval are displayed. 
     The user can confirm the display area of the observation image and the capturing interval which are displayed and proposed on the second display section  703  of the monitor  30  and can also set values equal to or less than proposed values as necessary. The device control software  101  restricts the value displayed on the second display section  703  according to the value set in the first display section  702  and the amount of available resources.  FIG. 8  is an example, and only one of the image size and the capturing interval may be displayed, or other elements may be displayable and selectable. 
     The invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above have been described in detail for easily understanding the invention, and the invention is not necessarily limited to those including all the configurations described above. In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. In addition, a part of the configuration of each embodiment can be added to, deleted from, or replaced with other configurations. A part or all of the configurations, functions, processing units, processing sections, and the like described above may be implemented by hardware, for example, by designing an integrated circuit. 
     REFERENCE SIGN LIST 
     
         
         
           
               10  . . . computer (control terminal),  11  . . . CPU,  12  . . . DRAM,  13  . . . ROM,  14  . . . hard disk drive (HDD),  15  to  18  . . . interface (I/F),  20  . . . charged particle beam device main body,  30  . . . monitor,  40  . . . remote control terminal,  101  . . . device control software,  103  . . . resource monitoring unit,  104  . . . allocation availability determination unit,  105  . . . operating system (OS),  106  . . . notification unit,  301  . . . remote control software,  401  . . . process list,  402  . . . process stop button,  403  . . . end button,  501  . . . camera unit,  601  . . . resource amount restriction setting screen,  602  . . . display unit,  603  . . . input unit,  701  . . . display area setting screen,  702  . . . first display section,  703  . . . second display section, T 1  to T 6  . . . terminal.