Abstract:
Provided is a charged particle beam device that is small, high performance, and easy to transport. A charged particle beam device ( 100 ) is provided with a detachable body unit ( 15 ) and an auxiliary unit ( 14 ), the body unit ( 15 ) housing a functional unit related to charged particle beams, and the auxiliary unit ( 14 ) housing a power source unit ( 9 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a charged particle beam apparatus. 
       BACKGROUND ART 
       [0002]    A scanning electron microscope (SEM) scans a sample with a converged electron beam, detects an electron generated from the sample by the scanning, and displays a scanning electron image of the sample on an image display device by using a detected signal thereof. The scanning electron microscope requires a high voltage of several tens of kilovolts in view of properties of an electron gun used in generating an electron beam. In addition, in order to secure a stable electron beam, the inside of the electron microscope has to remain evacuated, Therefore, the scanning electron microscope in the related art tends to increase in size. 
         [0003]    PTL 1 below discloses a configuration of an electron microscope (refer to  FIG. 2 ). In the electron microscope disclosed in PTL 1, an electron microscope main body including an electron source, an electron optical system, a sample chamber, a stage, and an exhaust system, a control device for controlling the electron microscope main body, and a monitor for displaying an observation image are respectively held in separate frames. 
         [0004]    PTL 1 below further discloses a structure of a desktop electron microscope which can be installed on a table or a workbench (refer to  FIG. 1 ). In the desktop electron microscope, the electron microscope main body including the electron source, the electron optical system, the sample chamber, the stage, and the exhaust system, and the control device are installed inside the same housing. 
       CITATION LIST 
     Patent Literature 
       [0005]    PTL 1: Pamphlet of International Publication No. WO2011/013323 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    According to a configuration illustrated in FIG. 2 in PTL 1, it is possible to provide an apparatus having excellent performance. However, since the size is large and the installation area is large, it is necessary to secure a wide installation space. In addition, when the apparatus is moved, it is essential to prepare a transport machine such as a lifter. When the apparatus is transported, a large truck needs to transport the apparatus. Thus, the transportation is time-consuming. Therefore, in a case where it is necessary to observe a sample prepared in a place having no electron microscope, the sample has to be observed after being transported to a research institute having the electron microscope. From a viewpoint of time, a user feels inconvenient. 
         [0007]    The desktop electron microscope illustrated in FIG. 1 in PTL 1 requires a smaller installation area and is easily transported. On the other hand, in view of the property that desktop installation is available, it is necessary to limit the performance of the apparatus in order to miniaturize the apparatus. 
         [0008]    The present invention is made in view of the above-described problem, and an object thereof is to provide a charged particle beam apparatus which is miniaturized, shows excellent performance, and is easily transported. 
       Solution to Problem 
       [0009]    The present invention relates to a charged particle beam apparatus configured so that a main body unit having a functional unit relating to a charged particle beam is detachably mounted on an auxiliary unit having a power supply unit for supplying power to the main body unit. 
       Advantageous Effects of Invention 
       [0010]    According to the present invention, the main body unit is miniaturized. Accordingly, it is possible to provide the charged particle beam apparatus which is miniaturized and shows excellent performance. In addition, the main body unit and the auxiliary unit are separated from each other. Accordingly, the charged particle beam apparatus can be easily transported. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]      FIG. 1  is a side view illustrating an overall configuration of a charged particle beam apparatus  100  according to Embodiment 1. 
           [0012]      FIG. 2  is a view illustrating a state where a rotary pump  8  is accommodated inside an auxiliary unit  14 . 
           [0013]      FIG. 3  is a side view illustrating a state where a user  40  sitting on a chair  41  operates the charged particle beam apparatus  100 . 
           [0014]      FIG. 4  is a view illustrating a height which enables reasonable sample replacement. 
           [0015]      FIG. 5  is a view illustrating a size example when the user  40  pulls out a sample stage  4  from a main body unit  15 . 
           [0016]      FIG. 6  is view illustrating an example in which main body unit  15  and the auxiliary unit  14  are separately installed. 
           [0017]      FIG. 7  is a side view illustrating an overall configuration of the charged particle beam apparatus  100  according to Embodiment 2. 
           [0018]      FIG. 8  is a front view of the main body unit  15 . 
           [0019]      FIG. 9  is a side view illustrating an overall configuration of the charged particle beam apparatus  100  according to Embodiment 3. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
       [0020]      FIG. 1  is a side view illustrating an overall configuration of a charged particle beam apparatus  100  according to Embodiment 1. The charged particle beam apparatus  100  includes a main body unit  15  and an auxiliary unit  14 . The main body unit  15  accommodates a charged particle beam source  1 , an electron optical system column  2  (including a focusing lens, an objective lens, and a detector), a sample chamber  3 , a sample stage  4 , a turbo-molecular pump  5  (main exhaust pump), an exhaust pipe  6  which connects the turbo-molecular pump  5  and the electron optical system column  2  or the sample chamber  3 , and a control board  7  which controls each unit. The auxiliary unit  14  accommodates a power supply unit  9  and a control board  10  which communicates with a computer  16 . 
         [0021]    A leg portion  12  for installing the auxiliary unit  14  and a caster  13  for transporting the auxiliary unit  14  are provided in a lower portion of the auxiliary unit  14 . A transport member other than the caster  13  may be used. A rotary pump  8  is an auxiliary exhaust pump, is installed outside the main body unit  15  and the auxiliary unit  14 , and is connected to the turbo-molecular pump  5  via the exhaust pipe. 
         [0022]    The main body unit  15  can be mounted on an upper portion of the auxiliary unit  14 . In this case, the main body unit  15  and the auxiliary unit  14  are fastened by a fastening member  17 , The main body unit  15  and the auxiliary unit  14  are installed so as to overlap each other. In this manner, without securing an installation area of the main body unit  15 , the overall charged particle beam apparatus  100  can be installed in only an installation area of the auxiliary unit  14 . 
         [0023]    It is desirable that a footprint of the main body unit  15  is configured to be substantially the same as a footprint of the auxiliary unit  14 . Specifically, it is conceivable that a bottom area of the main body unit  15  is substantially equal to (or smaller than) a top surface area of the auxiliary unit  14 . In this manner, even in a state where the two units are stacked on each other, a user can obtain a sense of unity as the overall charged particle beam apparatus  100 . 
         [0024]    The main body unit  15  and the auxiliary unit  14  are fastened to each other using the fastening member  17 . In this manner, all of the main body unit  15  and the auxiliary unit  14  can be regarded as one rigid body. When the charged particle beam apparatus  100  receives an external force F, an acceleration speed a received by the charged particle beam apparatus  100  can be expressed by “a=F/m” if the weight of the charged particle beam apparatus  100  is set to m. That is, the two units are fastened to each other, thereby increasing m. Compared to a case where the two units overlap each other without being fastened, it is possible to reduce the influence of vibrations when the external force is received. 
         [0025]    Some configuration elements such as the turbo-molecular pump  5  have limitations on an operation temperature (for example, 60° C. or lower). If the charged particle beam apparatus  100  is miniaturized, the respective configuration elements are close to each other. Accordingly, heat generated from the control board  10  or the electron optical system column  2  is accumulated inside the apparatus, and the temperature inside the apparatus is likely to rise. If the temperature inside the apparatus exceeds the operation temperature, the configuration elements are stopped or are abnormally operated. The control board  10  or the power supply unit  9  which generates a large amount of heat is disposed inside the auxiliary unit  14 . In this manner, it is possible to prevent the temperature rise inside the main body unit  15 . In addition, it is possible to reduce the number of waste heat fans installed inside the main body unit  15 . The waste heat fan which is a vibration source can be kept away from the electron optical system column  2 . Furthermore, there are provided plates for partitioning each unit such as a bottom plate of the main body unit  15  and an upper plate of the auxiliary unit  14 . Accordingly, a configuration can be adopted in which heat or electromagnetic noise generated from the auxiliary unit  14  is less likely to be transferred to the main body unit  15 . 
         [0026]    If vibrations are generated in the sample chamber  3  or the electron optical system column  2 , the performance of the charged particle beam apparatus  100  is adversely affected. For example, in a case where the charged particle beam apparatus  100  is configured to serve as a scanning electron microscope, an image is inaccurately observed. In particular, in order to perform high magnification observation, it is necessary that the charged particle beam apparatus  100  is less likely to receive the influence of external vibrations. Therefore, a vibration control mount  11  is disposed between the bottom surface of the main body unit  15  and the sample chamber  3 . For example, the vibration control mount  11  can be configured to include a vibration absorbing member such as a damper. The vibration control mount  11  can restrain the external vibrations from being propagated to the sample chamber  3  or the electron optical system column  2 . 
         [0027]    The leg portion  12  includes a vibration control mechanism  18 . For example, the vibration control mechanism  18  can be configured using a vibration absorbing member such as rubber. The vibration control mechanism  18  can restrain vibrations generated on the ground from being propagated to the auxiliary unit  14  or the main body unit  15 . As a result, it is possible to minimize vibrations propagated to the sample chamber  3  or the electron optical system column  2 . 
         [0028]    The caster  13  is disposed in the lower portion of the auxiliary unit  14 . The caster  13  can concurrently transport the auxiliary unit  14  and the main body unit  15  in a state where the two units overlap each other (or in a state where the two units are further fastened to each other by the fastening member  17 ). 
         [0029]      FIG. 2  is a view illustrating a state where the rotary pump  8  is accommodated inside the auxiliary unit  14 . In addition to a space for accommodating the power supply unit  9  and the control board  10 , a space for accommodating the rotary pump  8  and other members can be disposed inside the auxiliary unit  14 . In this manner, even in a case where the rotary pump  8  is installed outside the charged particle beam apparatus  100  when in use, these machines can be concurrently transported during the transportation. For example, when the main body unit  15  and the auxiliary unit  14  are separated from each other as in  FIG. 6  (to be described later), the above-described space inside the auxiliary unit  14  can be used in order to accommodate a wire for connecting both unit in the space. 
         [0030]    According to the desktop electron microscope in the related art, a position of the sample stage is 800 to 1,000 mm from the ground. A user  40  needs to raise his or her arm a little in order to pull out the sample stage while sitting on a chair  41 . In addition, even in a case of a large-scale electron microscope in the related art, similarly to the desktop electron microscope, the position of the sample stage is approximately 1,000 mm from the ground. The user  40  needs to pull out the sample stage in a state where the user  40  raises his or her arm. In addition, according to the desktop electron microscope in the related art, a load plate is disposed below the sample chamber having the sample stage attached thereto, and the load plate is larger in the peripheral direction than the sample stage or the sample chamber (refer to FIG. 2 in PTL 1). Therefore, the user  40  has difficulties in moving close to the apparatus while sitting on the chair  41 . The user  40  has to pull out the sample stage  4  after extending his or her arm or standing up from the chair  41 . Therefore, the charged particle beam apparatus  100  according to the present embodiment employs a size which enables the user to reasonably carry out work. 
         [0031]      FIG. 3  is a side view illustrating a state where the user  40  sitting on the chair  41  operates the charged particle beam apparatus  100   FIG. 3  illustrates a size example of each unit. The height of the auxiliary unit  14  is substantially equal to the height of the chair  41  (In  FIG. 3 , the height of the chair  41  is 380 to 410 mm, and the height of the auxiliary unit  14  is 400 mm). The height of the main body unit  15  is 800 mm. When the user  40  replaces the sample, the sample stage  4  pulled out from the main body unit  15  is located at a position of 500 to 750 mm from the ground. This height is substantially equal to the height of the hand when the user  40  places the hand on the knee. Therefore, even in a state where the user  40  sits on the chair, the user  40  can comfortably pull out the sample stage  4 . 
         [0032]    In Embodiment 1, the most important height in terms of usability is the height of the sample stage  4  (sample replacement position) where the user actually touches with the hand, and shows 640 mm. This height is determined, based on the idea as illustrated in  FIG. 4 . 
         [0033]    As a big person&#39;s body size, men in a range of 95% are assumed (American men&#39;s height 189.5 cm). As a small person&#39;s body size, women in a range of 5% are assumed (Asian women&#39;s height 147.1 cm). In addition, as the maximum height of the hand in a posture which enables reasonable sample replacement, it is assumed that a shoulder&#39;s angle is set to 45 degrees forward from the body center and an elbow&#39;s angle is set to 90 degrees. As the minimum height of the hand, it is assumed that the shoulder&#39;s angle is set to zero degrees from the body center and the elbow&#39;s angle is set to 120 degrees. As a result, it is determined that a range of the height of the sample stage  4  which enables the big person to reasonably replace the sample is 505.5 mm to 1,169 mm, and that a range of the height of the sample stage  4  which enables the small person to reasonably replace the sample is 436 mm to 800 mm. The range of 505 mm to 800 mm where the two ranges overlap each other shows the optimum height of the sample stage  4  which enables not only the big person but also the small person to reasonably replace the sample. The height 640 mm of the sample stage  4  according to the present embodiment is a substantially intermediate position of an ideal range. Therefore, there is an advantageous effect in that many users  40  comfortably carry out work. 
         [0034]      FIG. 5  is a view illustrating a size example when the user  40  pulls out the sample stage  4  from the main body unit  15 . The sample  43  is located at the position of 640 mm from the ground. Accordingly, similarly to when the sample stage  4  is pulled out, the user  40  can replace the sample  43  without raising the arm. In addition, when the sample stage  4  is pulled out, the user  40  can look down the sample  43  from above. Accordingly, the user  40  can observe a state of the sample  43  without detaching the sample  43  from the sample stage  4  or standing up by himself or herself. On the other hand, according to the desktop electron microscope or the large-scale electron microscope in the related art, the height of the sample  43  is approximately 1,000 mm from the ground. In a state of the user  40  sitting on the chair, the user  40  can only laterally or obliquely observe the sample  43 . According to the size example illustrated in  FIG. 5 , it is possible to improve operability when the sample is replaced. 
         [0035]    The footprint of the main body unit  15  is substantially the same as the footprint of the auxiliary unit  14 . Accordingly, in a state where the sample stage  4  is pulled out from the main body unit  15 , a space is affordable below the main body unit  15 . Since the user  40  can place the feet into the space, the user  40  can more flexibly carry out work for the sample stage  4 . 
         [0036]      FIG. 6  is view illustrating an example in which the main body unit  15  and the auxiliary unit  14  are separately installed. The fastening member  17  is detached therefrom. In this manner, the main body unit  15  and the auxiliary unit  14  can be installed at respectively separated positions. The main body unit  15  and the auxiliary unit  14  are connected to each other by a wire for control or power supply or a pipe for connecting a back pump. The auxiliary unit  14  and the computer  16  are connected to each other by a wire. 
         [0037]    In an environmental case where a user stands and carries out work in a clean room, instead of a state where the two unit overlap each other as illustrated in  FIG. 1 , if the user uses the apparatus in a state where the main body unit  15  is placed on the desk  23  as illustrated in  FIG. 6 , the user can pull out the sample stage  4  without bending down when the user replaces the sample. In this way, depending on a user, a use state of the charged particle beam apparatus  100  differs. Accordingly, since each unit is configured to be attachable and detachable, the charged particle beam apparatus  100  can correspond to a wide range of user&#39;s environment. Furthermore, in a case where high magnification observation is performed in an environment where external vibrations are frequently generated, a vibration control table may be installed in the lower portion of the apparatus. According to the large-scale electron microscope in the related art, the overall apparatus has to be mounted on the vibration control table, and thus, a large-scale vibration control table is required. The apparatus can be mounted on the vibration control table by separating the main body unit  15  therefrom. Therefore, it is possible to minimize a size of the vibration control table or load withstanding. 
         [0038]    Since the respective units are separated from each other, the respective units can also be loaded on a low-height vehicle during transportation. Therefore, the apparatus can be transported without using a large-size vehicle such as a truck. In this manner, the apparatus can be transported using a small-size vehicle. Therefore, not only the charged particle beam apparatus  100  can be conveniently transported, but also can be transported to a narrow place. 
         [0039]    As described referring to  FIGS. 3 to 5 , the height is configured to be suitable for the user  40  to carry out work while sitting on the chair  41  in a state where the main body unit  15  is mounted on the auxiliary unit  14 . However, since the main body unit  15  is separated and mounted on the desk  23 , the height can be differently adjusted depending on the desk  23 . 
         [0040]    When the charged particle beam apparatus  100  partially fails, the charged particle beam apparatus  100  can be quickly recovered by replacing either the main body unit  15  or the auxiliary unit  14 . The charged particle beam apparatus in the related art is large-sized and troublesome in transportation. However, the charged particle beam apparatus  100  according to Embodiment 1 can be transported using a small-size vehicle. Accordingly, mobility is satisfactory, and a user can quickly correspond to each unit. In addition, after repairing a failed unit, the user can replace the failed unit with a new one again. According to these characteristics, it is possible to improve an operation rate of the charged particle beam apparatus  100 . 
         [0041]    When the main body unit  15  and the auxiliary unit  14  are separated from each other, a wire for connecting both units is required. Since this wire causes noise, it is desirable that the wire is as short as possible. The wire can be shortened by disposing a member connected to both ends of the wire in an end inside the unit as possible. For example, it is conceivable that the power supply unit  9  is disposed close to the upper surface inside the auxiliary unit  14  and that the control board  7  is disposed close to the bottom surface inside the main body unit  15 . 
         [0042]    As described above, in the charged particle beam apparatus  100  according to Embodiment 1, while a characteristic that desktop installation is available is maintained, the power supply unit  9  or the control board  10  which does not affect the performance or function of the charged particle beam apparatus  100  is disposed inside the auxiliary unit  14  separated from the main body unit  15 . In this manner, the main body unit  15  can be miniaturized. As the main body unit  15  is miniaturized, the charged particle beam apparatus  100  can be highly functionalized, and multi-functions can be realized so that the charged particle beam apparatus  100  can correspond to high vacuum and low vacuum. 
         [0043]    The charged particle beam apparatus  100  according to Embodiment 1 can be used in a state where the main body unit  15  and the auxiliary unit  14  overlap each other, or can be used in a state where both units are separated from each other, for example, in a state where the main body unit  15  is installed on the desk. In a case where both units overlap each other, it is possible to prevent an installation area of the auxiliary unit  14  from being enlarged. In a case where both units are separated from each other, the main body unit  15  can be installed in a user&#39;s desired place such as a desk or a workbench. That is, it is possible to widely correspond to various installation environments. 
         [0044]    The charged particle beam apparatus  100  according to the present embodiment can be transported without using a large-size vehicle since the respective units are separated from each other during the transportation. Therefore, it is possible to provide transportability which is the same as that of the desktop electron microscope while excellent performance is maintained. 
       Embodiment 2 
       [0045]      FIG. 7  is a side view illustrating an overall configuration of the charged particle beam apparatus  100  according to the present embodiment. In the present embodiment, instead of the vibration control mount  11  described in Embodiment 1, a vibration control mount  35  is provided. Hereinafter, points different from those in Embodiment 1 will be mainly described. 
         [0046]    The vibration control mount  35  is attached between a vibration control mount attachment member  36  fixed to a side surface of the sample chamber  3  and a vibration control mount base  34  fixed to a frame of the main body unit  15 . In addition, an exhaust pipe support member  31  for supporting the exhaust pipe  6  is provided. One end of the exhaust pipe support member  31  is connected to the exhaust pipe  6 , and the other end is connected to an outer wall of the sample chamber  3 . Furthermore, a fork inserting guide  32  is disposed on the bottom surface of the main body unit  15 , and a positioning member  33  is disposed on the upper surface of the auxiliary unit  14 . 
         [0047]    According to the electron microscope in the related art illustrated in FIG. 2 in PTL 1, the vibration control mount is disposed between the load plate disposed below the sample chamber and the frame. A natural frequency f of the vibration control mount is expressed by “f=(k/m) 1/2 ” if the weight placed on the vibration control mount is set to m and a spring constant of the vibration control mount is set to k. That is, the natural frequency f can be decreased by increasing the weight. If vibration amplitude is constant, as the frequency decreases, acceleration decreases. Accordingly, as the natural frequency f decreases, a vibration control effect is improved. As the load plate disclosed in PTL 1, a material such as iron is used. The weight of the material is as heavy as several 10 kg. Accordingly, the vibration control effect is excellent. However, according to the configuration described in Embodiment 1, the load plate is removed, and the sample chamber  3  or the electron optical system column  2  is miniaturized so that the main body unit  15  can be mounted on the desk. 
         [0048]    Accordingly, the vibration control effect obtained by the vibration control mount  11  is weakened. In addition, if the vibration control mount  11  is disposed in the lower portion of the sample chamber  3 , a size of the vibration control mount  11  is limited, thereby restraining the vibration control effect. 
         [0049]    Therefore, according to Embodiment 2, the vibration control mount  35  is installed in a side portion of the sample chamber  3 . In addition to this configuration, the vibration control mount base  34  fixed to the frame of the main body unit  15  and the vibration control mount attachment member  36  fixed to the side surface of the sample chamber  3  are provided. The side surface of the sample chamber  3  has a space to which a detector is attached. Accordingly, even in a case where the vibration control mount  35  is installed in the side portion of the sample chamber  3 , the width of the main body unit  15  does not increase. That is, the vibration control mount  35  can become larger than that according to Embodiment 1 without increasing the size of the charged particle beam apparatus  100 . Therefore, it is possible to improve the vibration control effect of the vibration control mount. 
         [0050]      FIG. 8  is a front view of the main body unit  15 . The upper surface of the vibration control mount  35  is disposed so as to be substantially coincident with the height of the center of gravity  45  of the main body of the charged particle beam apparatus  100 . In this manner, a vibration mode such as pitching and rolling is less likely to occur. In addition, the sample  43  is located at the height which is substantially the same as that of the upper surface of the vibration control mount  35  and the center of gravity  45 . Therefore, even in a case where the vibration mode occurs, the rotation center is located near the sample  43 , and the vibration amplitude near the sample  43  decreases. Accordingly, the influence of the vibrations can be minimized. 
         [0051]    According to Embodiment 2, unlike FIG. 2 in PTL 1, the turbo-molecular pump  5  is not attached to the lower portion of the sample chamber  3 , and is attached to the exhaust pipe  6  which is connected to the electron optical system column  2  or the sample chamber  3  and which extends rearward in the apparatus. In this manner, the apparatus is miniaturized by lowering the height of the main body unit  15 . 
         [0052]    In addition, the weight of the turbo-molecular pump  5  is approximately 3 kg. Accordingly, in a case where the turbo-molecular pump  5  is attached to the exhaust pipe  6 , it becomes similar to a cantilever structure. Therefore, a two-freedom-degree vibration system using the vibration control mount  35  and the exhaust pipe  6  is formed, and an extra vibration mode appears, thereby causing a possibility that the vibration control performance may become poor. Therefore, according to Embodiment 2, the exhaust pipe support member  31  fixed to the sample chamber  3  is fastened to the exhaust pipe  6 , thereby supporting the exhaust pipe  6 . In this manner, it is possible to increase the natural frequency of the vibration system which is caused by the exhaust pipe  6  and the turbo-molecular pump  5 . According to the above-described configuration, a difference increases between the natural frequency of the vibration system and the natural frequency of the vibration control mount  35 . It is possible to minimize the influence on the vibration mode of the vibration control mount  35  which is exerted by the vibration mode of the exhaust pipe  6 . In addition, the turbo-molecular pump  5  is a vibration source rotating at approximately 1,500 Hz during a steady operation. The natural frequency in a high-order mode of the exhaust pipe  6  is set to a frequency different from the rotation speed of the turbo-molecular pump  5  by the exhaust pipe support member  31 . In this manner, it is possible to minimize the influence of the vibrations caused by the rotation of the turbo-molecular pump  5 . 
         [0053]    The main body unit  15  is lighter than that of the electron microscope in the related art. For example, the main body unit  15  has the weight of approximately 80 kg. Therefore, when the respective units are attached or detached, when the main body unit  15  is installed on the desk, and when the respective units are transported, it is assumed that a user uses a lifter. Therefore, two rectangular fork inserting guides  32  are fixed to the lower portion of the main body unit  15 . In view of the center of gravity of the main body unit  15 , it is desirable that the center of gravity of the main body unit  15  is located at the center of the two fork inserting guides  32 . If a fork of the lifter is inserted into the fork inserting guides  32 , the main body unit  15  can be lifted in a stable state. The position for inserting the fork is determined as the same position every time by the fork inserting guides  32 . Accordingly, it is possible to ensure stability when the main body unit  15  is lifted without depending on a worker. 
         [0054]    The positioning member  33  is a member which assists positioning when the main body unit  15  is mounted on the auxiliary unit  14 . For example, a configuration is adopted in which a slit is disposed in the fork inserting guides  32  and the positioning member  33  is fitted to the slit. In this manner, the main body unit  15  can be mounted on the same position every time in  FIG. 7 , the positioning member  33  is disposed to be positioned in only the longitudinal direction (lateral direction toward the drawing) of the charged particle beam apparatus  100 . However, a member for positioning the charged particle beam apparatus  100  in the lateral direction (depth direction toward the drawing) may be provided. 
         [0055]    As described above, the charged particle beam apparatus  100  according to Embodiment 2 can improve vibration control performance while minimizing the size of the main body unit  15  by disposing the vibration control mount  35  in the side portion of the sample chamber  3 . In addition, the influence of the vibrations caused by the turbo-molecular pump  5  can be minimized by providing a member for supporting the exhaust pipe  6 . 
         [0056]    The charged particle beam apparatus  100  according to Embodiment 2 includes the positioning member  33  and the fork inserting guide  32  in order to assist work for mounting the main body unit  15  on the auxiliary unit  14 . These members enable a user to efficiently carry out work such as installation, separation, and combination of the respective units. 
         [0057]    When the charged particle beam apparatus  100  is transported and installed, any one of the following aspects can be adopted in view of conditions such as an installation environment, transportation facilities, and a distance up to the installation environment. (a) The main body unit  15  is mounted on the auxiliary unit  14 , and is transported by a transportation vehicle or the caster  13 . (a1) Both units are separated from each other at the installation place, and are respectively installed. Alternatively, (a2) both units are installed while maintaining a state where the main body unit  15  is mounted on the auxiliary unit  14  at the installation place. (b) The auxiliary unit  14  and the main body unit  15  are separated from each other, and are individually transported by the transportation vehicle or the caster  13 . (b1) Both units are installed while maintaining a state where both units are separated from each other at the installation place, Alternatively, (b2) the main body unit  15  is mounted and installed on the auxiliary unit  14  at the installation place. 
       Embodiment 3 
       [0058]    In Embodiments 1 and 2, a configuration example has been described which includes the main body unit  15  and the auxiliary unit  14 , In some cases, depending on a user&#39;s demand, it becomes necessary to additionally mount a configuration element such as a detector, and it becomes necessary to add a control board for operating the detector. Embodiment 3 adopts a configuration example in which the installation area is not changed while portability is maintained even in such circumstances. Hereinafter, points different from those according to Embodiments 1 and 2 will be mainly described. 
         [0059]      FIG. 9  is a side view illustrating an overall configuration of the charged particle beam apparatus  100  according to Embodiment 3. An option detector  50  is installed inside the sample chamber  3 . An option unit  52  which accommodates a control board  51  for controlling the option detector  50  is installed between the main body unit  15  and the auxiliary unit  14 . The respective units can overlap each other. The main body unit  15  and the option unit  52 , and the auxiliary unit  14  and the option unit  52  are fastened to each other by the fastening member  17 . The option detector  50 , the control board  51 , and the power supply unit  9  are connected to each other by a wire. The footprint of the option unit  52  is substantially the same as the footprint of the main body unit  15  or the auxiliary unit  14 . 
         [0060]    The option unit  52  is added thereto, In this manner, without increasing the installation area of the overall charged particle beam apparatus  100 , it is possible to add a configuration element which cannot be installed inside the main body unit  15  or inside the auxiliary unit  14 . The configuration element accommodated inside the option unit  52  can be appropriately changed depending on a configuration element to be added. Specifically, those which are not accommodated in either the main body unit  15  or the auxiliary unit  14  in devices or members provided with functions by the charged particle beam apparatus  100  may be accommodated therein. 
         [0061]    The number of configuration elements accommodated inside the option unit  52  is not limited to one. For example, other control boards or power sources can be accommodated. In addition, multiple option units  52  may be additionally installed. The respective units are configured so as to overlap each other. Accordingly, even if a function of the charged particle beam apparatus  100  is added by the option unit  52 , the installation area is not changed, thereby maintaining familiar usability and design of the apparatus. In addition, all of the units can be transported at the same time by using the caster  13 . 
         [0062]    The option unit  52  can be used in order to adjust the height of the main body unit  15 . Depending on a user, a physical condition or familiar usability varies. Accordingly, the option unit  52  is used as a height adjusting spacer, thereby allowing the height of the main body unit  15  from the ground to be variable. In this manner, it is possible to provide excellent operability for a wide range of users. In addition, since the option unit  52  is used as a vibration control table, it is possible to improve a vibration control effect. 
       Modification Example of Present Invention 
       [0063]    Without being limited to the above-described embodiments, the present invention includes various modification examples. The above-described embodiments are provided in order to easily and specifically describe the present invention, and are not necessarily limited to those which include all of the described configurations. In addition, configurations according to a certain embodiment can be partially replaced with configurations according to the other embodiment. In addition, configurations according to the other embodiment can be added to configurations according to the certain embodiment. In addition, other configurations can be added to, deleted from, or replaced with configurations according to the respective embodiments. 
       REFERENCE SIGNS LIST 
       [0064]      1 : CHARGED PARTICLE BEAM SOURCE, 
         [0065]      2 : ELECTRON OPTICAL SYSTEM COLUMN, 
         [0066]      3 : SAMPLE CHAMBER, 
         [0067]      4 : SAMPLE STAGE, 
         [0068]      5 : TURBO-MOLECULAR PUMP, 
         [0069]      6 : EXHAUST PIPE, 
         [0070]      7 : CONTROL BOARD, 
         [0071]      8 : ROTARY PUMP, 
         [0072]      9 : POWER SUPPLY UNIT, 
         [0073]      10 : CONTROL BOARD, 
         [0074]      11 : VIBRATION CONTROL MOUNT, 
         [0075]      12 : LEG PORTION, 
         [0076]      13 : CASTER, 
         [0077]      14 : AUXILIARY UNIT, 
         [0078]      15 : MAIN BODY UNIT, 
         [0079]      16 : COMPUTER, 
         [0080]      17 : FASTENING MEMBER, 
         [0081]      18 : VIBRATION CONTROL MECHANISM 
         [0082]      19 : DESK, 
         [0083]      31 : EXHAUST PIPE SUPPORT MEMBER, 
         [0084]      32 : FORK INSERTING GUIDE, 
         [0085]      33 : POSITIONING MEMBER, 
         [0086]      34 : VIBRATION CONTROL MOUNT BASE, 
         [0087]      35 : VIBRATION CONTROL MOUNT, 
         [0088]      36 : VIBRATION CONTROL MOUNT ATTACHMENT MEMBER, 
         [0089]      40 : USER, 
         [0090]      41 : CHAIR, 
         [0091]      43 : SAMPLE, 
         [0092]      45 : CENTER OF GRAVITY, 
         [0093]      50 : OPTION DETECTOR, 
         [0094]      51 : CONTROL BOARD, 
         [0095]      52 : OPTION UNIT