Abstract:
Disclosed is a holder device for an electron microscope, which efficiently collects light emitted when electrons collide with a sample inside the electron microscope and is selectively usable in various electron microscopes since it can be easily attached to and detached from the electron microscopes. The holder device includes a frame; a sample support block configured to be supported on the frame and comprising a sample mounting portion to support an edge of a sample; a mirror unit configured to comprise an upper mirror and a lower mirror respectively arranged above and below the sample and reflect light radiating from the sample, which is mounted to the sample mounting portion and to which an electron beam is emitted, in a predetermined direction; a condensing lens configured to condense light from the mirror unit on a predetermined target; and an optical fiber configured to collect light from the condensing lens.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Phase application of International Patent Application PCT/KR2013/007170 filed on Aug. 8, 2013, which designates the United States and claims priority of Korean Patent Application No. 10-201 2-0109933 filed on Oct. 4, 2012, and Korean Patent Application No. 10-201 3-0091603 filed on Aug. 1, 2013, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a holder device for an electron microscope. 
       BACKGROUND OF THE INVENTION 
       [0003]    To ascertain a band gap of the material, there is a need of collecting and analyzing light caused by cathodoluminescence, which occurs when an electron beam is applied to a material. In general, the collection of the light based on the cathodeluminescence is performed inside an electron microscope, and thus the electron microscope includes a main tube mounted with additional elements such as a reflection mirror needed for collecting the cathodoluminescence light. 
         [0004]    A conventional electron microscope capable of collecting the cathodoluminescence is relatively bulky and complicated and pretty expensive because of the additional elements. Further, there is a limit that the cathodoluminescence is collectable in only the electron microscope having such a function. However, the conventional electron microscope mounted with the elements for collecting the cathodoluminescence has a structure of collecting the cathodoluminescence generated from one surface of a sample, and therefore obtained information is relatively small in quantity and not accurate. 
       SUMMARY OF THE INVENTION 
       [0005]    An aspect of the invention is to provide a holder device for an electron microscope, in which elements needed for collecting cathodoluminescence are modularized into a compact unit and universally applicable to commercialized electron microscopes, and have a high efficiency of collecting cathodoluminescence. 
         [0006]    The foregoing and/or other aspects of the present invention are achieved by providing a holder device for an electron microscope including: a frame; a sample support block configured to be supported on the frame and include a sample mounting portion to support an edge of a sample; a mirror unit configured to include an upper mirror and a lower mirror which are respectively arranged above and below the sample and reflect light radiating from the sample, which is mounted to the sample mounting portion and to which an electron beam is emitted, in a predetermined direction; a condensing lens configured to condense light from the mirror unit on a predetermined target; and an optical fiber configured to collect light from the condensing lens. 
         [0007]    The mirror unit may include a sample approach slit configured to be arranged in between the upper mirror and the lower mirror and allow the sample mounting portion to move in and out along a surface of the sample. 
         [0008]    The mirror unit may include an electron through hole via which the electron beam emitted to the sample passes. 
         [0009]    The condensing lens may be supported on the mirror unit so that it allows high efficiency of collecting light and stability of fixing lens. 
         [0010]    The holder device for an electron microscope may further include: an optical fiber holder configured to hold the optical fiber; and a coupler configured to couple the optical fiber holder and the mirror unit. 
         [0011]    The coupler may be movably supported on the frame so that the mirror unit can reciprocate between an inspection position where the sample mounting portion is placed within the mirror unit and an idle position where the sample mounting portion is separated from the mirror unit. With these configurations, it is available to perform various different analysis using the electron microscope. 
         [0012]    A slide pin extended in parallel with a lengthwise direction of the frame may be coupled to one of the mirror unit and the sample support block, and a guide may be provided in the other of the mirror unit and the sample support block and guides the slide pin to slide relatively. With these configurations, it is stable for mobility of the mirror unit. 
         [0013]    The holder device for an electron microscope may further include: a support rod configured to include one end portion to which the frame is detachably coupled and an axial hole through which the optical fiber passes; and a grip portion configured to be provided at the other end portion of the support rod. 
         [0014]    According to an exemplary embodiment, there is provided a holder device for an electron microscope, which has a shape similar to a sample support holder used in a general electron microscope and has a compact structure universally installable and usable in various electron microscopes without an environmental limit of given equipment. Further, this holder device for an electron microscope has a high efficiency of collecting cathodoluminescence since mirrors are arranged at both sides of a sample. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view showing a holder device for an electron microscope according to an exemplary embodiment, 
           [0016]      FIGS. 2 to 4  are assembled views and a partial exploded perspective view of a head, which are to explain a head portion of a holder device for an electron microscope according to an exemplary embodiment, 
           [0017]      FIGS. 5 and 6  are perspective views for explaining a sample support block and an assembly relationship between the sample support block and a mirror unit according to an exemplary embodiment, 
           [0018]      FIG. 7  is a perspective view showing a coupling relationship among the mirror unit, a lens and a coupler according to an exemplary embodiment, 
           [0019]      FIG. 8  is a rear view of the mirror unit according to an exemplary embodiment, and 
           [0020]      FIG. 9  is an optical concept view for explaining a light condensing mechanism of the holder device for the electron microscope according to an exemplary embodiment. 
       
    
    
       [0021]    For reference, numerals in drawings are as follows. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                  1: Head 
                 10: Support Rod 
               
               
                   
                 11: Grip 
                 20: Frame 
               
               
                   
                 21: Fixture 
                 22: Frame Arm 
               
               
                   
                 23: Mounting Screw 
                 24: Adjustment Screw 
               
               
                   
                 30: Sample Support Block 
                 31: Holding Block 
               
               
                   
                 32: Protrusion 
                 33: Fastening Hole 
               
               
                   
                 34: Bridge 
               
               
                   
                 35: Sample Mounting Portion 
               
               
                   
                 36: Slide Insertion Hole 
               
               
                   
                 37: Mounting Raised Portion 
               
               
                   
                 38: Copper Tube Hold Portion 
               
               
                   
                 39: Mounting Hole 
               
               
                   
                 40: Optical Fiber 
                 41: Copper Tube 
               
               
                   
                 50: Coupler 
                 51: Optical Fiber Holder 
               
               
                   
                 53: Optical Fiber Insertion Hole 
               
               
                   
                 60: Lens 
               
               
                   
                 70: Mirror Unit 
                 71: Electron Through Hole 
               
               
                   
                 72: Guide Insertion Portion 
               
               
                   
                 73: Sample Approach Slit 
               
               
                   
                 74: Lens Mounting Portion 
                 75: Upper Mirror Portion 
               
               
                   
                 76: Upper Mirror Surface 
                 77: Lower Mirror Portion 
               
               
                   
                 78: Lower Mirror Surface 
                 79: Extended Portion 
               
               
                   
                 80: Slide Guide 
                 81: Slide Guide Hole 
               
               
                   
                 90: Sample 
               
               
                   
                 91: Sample Arrangement Pin 
               
               
                   
                   
               
             
          
         
       
     
       DETAILED DESCRIPTION OF THE INVENTION 
       [0022]      FIG. 1  is a perspective view showing a holder device for an electron microscope according to an exemplary embodiment. As shown in  FIG. 1 , the holder device is provided in the form of a long rod, and includes a support rod  10  to be inserted in the electron microscope, and a holder grip  11  coupled to one end portion of the support rod  10  and fixed to a main body of the electron microscope so as to be gripped by a worker. Further, a head  1  is mounted to the other end portion of the support rod  10  so as to support a sample  90  to be analyzed and collect cathodoluminescence generated in the sample  90 . 
         [0023]      FIGS. 2 to 4  are assembled views and a partial exploded perspective view of the head  1 , which are to explain the head  1  of the holder device for an electron microscope according to an exemplary embodiment. As shown therein, the head  1  includes a frame  20  coupled to the support rod  10 . The frame  20  is coupled to an end of the support rod  10  and includes a pair of frame arms  22  extended in parallel with each other in a lengthwise direction of the support rod  10 . The support rod  10  is shaped like a tube and accommodates a copper tube  41  in its axial direction, and an optical fiber  40  penetrates the copper tube  41  in the axial direction. 
         [0024]    The copper tube  41  is exposed at the end of the support rod  10  and extended to a region of the frame arms  22 . A fixture  21  for fixing the position of the copper tube  41  is installed to the frame arms  22  by a mounting screw  23 . The fixture  21  includes a through hole formed in the axial direction of the support rod  10 , and the copper tube  41  is coaxially accommodated in the through hole of the fixture  21 . Further, adjustment screws  24  opposite to each other are inserted in the fixture  21  in a radial direction, and thus stably fix the copper tube  41  on to a central axis in which a light beam travels. 
         [0025]    One end of the optical fiber  40  accommodated in the copper tube  41  is inserted in and coupled to an optical fiber holder  51  shaped like a tube. The optical fiber holder  51  is coaxially and integrally coupled to a coupler  50  shaped like a tube having a relatively large diameter. The other end of the optical fiber  40  is connected to an external device of the electron microscope. 
         [0026]    A sample support block  30  is installed in between both the frame arms  22 . Referring to the enlarged perspective views of  FIGS. 5 and 6  together with  FIGS. 2 to 4 , the sample support block  30  includes a sample mounting portion  35  for supporting an edge of the sample  90 , and a copper tube hold portion  38  for accommodating about half of the exterior of the copper tube  41 . The sample mounting portion  35  and the copper tube hold portion  38  are connected by a pair of bridges  34  extended in parallel in the longitudinal direction of the sample support block  30 . There is an opened area in between the pair of bridges  34 . 
         [0027]    The sample mounting portion  35  has a semicircular shape and supports an edge of a sample. There is a hole in a center portion of the sample mounting portion  35  so that an electron beam can pass through the center portion. The sample mounting portion  35  is formed with a mounting raised portion  37  having a height corresponding to a thickness of a sample  90  so that the sample  90  can be stably mounted thereto. If a sample  90  is stably mounted to the sample mounting portion  35 , the sample  90  is fixed by the sample arrangement pin  91 . 
         [0028]    The copper tube hold portion  38  has a curved shape to receive the copper tube  41 . A hold block  31  including a copper tube hold portion  38  having a curved shape corresponding to the copper tube hold portion  38  is coupled to the sample support block  30  by screws inserted into a pair of fastening holes  33 , leaving the copper tube  41  between the hold block  31  and the sample support block  30 . 
         [0029]    Mounting holes  39  are formed by penetrating end portions of the sample support block  30  and the frame arms  22  in a traverse direction to the axial direction. By inserting an arrangement fin to the mounting holes  39 , the pair of frame arms  22  and the sample support block  30  are coupled. 
         [0030]    A pair of protrusions  32  is formed in a region of bridges  34  contacting the copper tube hold portion  38  and protrudes by a predetermined height in a height direction. Each protrusion  32  is formed with a slide insertion hole  36  in the axial direction so that a slide guide  80  can be inserted in the slide insertion hole  36 . The slide guide  80  inserted in and coupled to the slide insertion hole  36  in the axial direction is accommodated in a mirror unit  70  and guides movement of the mirror unit  70 . 
         [0031]    The mirror unit  70  includes a sample approach slit  73  allowing the sample mounting portion  35  to move in and out along a surface of a sample  90 , and an upper mirror portion  75  and a lower mirror portion  77  divided with the sample approach slit  73  therebetween. On the top surface of the upper mirror portion  75  is formed an electron through hole  71  to which an electron beam is emitted. The electron through hole  71  is formed by straightly penetrating the upper mirror portion  75  and the lower mirror portion  77  in the height direction. An extended portion  79  is provided at an axial opposite side of the upper mirror portion  75  and the lower mirror portion  77  and extended to have a predetermined length in the state that the upper portion is opened. A region, where the extended portion  79  starts being extended from the upper mirror portion  75  and the lower mirror portion  77 , serves as a lens mounting portion  74  to which a lens  60  is mounted. 
         [0032]    A guide insertion portion  72  is provided at the lateral sides of the mirror unit  70  and protrudes in lateral directions. The guide insertion portion  72  is formed with a slide guide hole  81  penetrated in the axial direction so as to receive a slide guide  80 . 
         [0033]    As shown in  FIG. 6 , in the state that the slide guide  80  is inserted in the slide guide hole  81 , the mirror unit  70  moves down in the height direction of the sample support block  30  and is then inserted in the opened area between the bridges  34 . Thus, a lower portion of the lower mirror portion  77  is inserted in the opened area between the bridge  34 , and the pair of guide insertion portions  72  are supported on the pair of bridges  34 . 
         [0034]    In such a state that the guide insertion portions  72  are supported on the sample support block  30 , the slide guide  80  is inserted and fixed in the slide insertion hole  36 . Therefore, the mirror unit  70  can lengthwise reciprocate along the slide guide  80 . 
         [0035]      FIG. 7  is a perspective view showing a coupling relationship among the mirror unit  70 , the lens  60  and a coupler  50  according to an exemplary embodiment. As shown in  FIG. 7 , the lens  60  is supported on the lens mounting portion  74 . The lens  60  serves to condense light reflected from an upper mirror surface  76  and a lower mirror surface  78  on an end surface of the optical fiber  40 . 
         [0036]    Further, the coupler  50  may be fitted into or adhered to the extended portion  79 . The coupler  50  may be provided integrally with the optical fiber holder  51 . An optical fiber insertion hole  53  penetrates the optical fiber holder  51  in the axial direction. The optical fiber  40  is inserted in the optical fiber insertion hole  53  and coupled to the optical fiber holder  51 . At this time, the end of the optical fiber  40  is positioned at a point on which the light from the lens  60  is converged. When the position of the optical fiber  40  is set, the optical fiber holder  51  and the optical fiber  40  are fixed to each other. 
         [0037]      FIG. 8  is a rear view of the mirror unit according to an exemplary embodiment. The upper mirror portion  75  and the lower mirror portion  77  are formed with the upper mirror surface  76  and the lower mirror surface  78  having parabolic shapes, respectively. The upper mirror surface  76  and the lower mirror surface  78  are provided to reflect light from a sample  90  toward the lens mounting portion  74 . There is a through space in between the upper and lower mirror surfaces  76  and  78  and the lens mounting portion  74 . 
         [0038]    With the foregoing structure, the holder device for an electron microscope according to an exemplary embodiment has a function of condensing light. 
         [0039]    A process of collecting cathodoluminescence caused by collision between an electron beam and a sample  90  is as follows. First, in an idle position where the sample mounting portion  35  is separated from the mirror unit  70 , a sample  90  to be analyzed is mounted to the sample mounting portion  35  and fixed by the sample arrangement pin  91  as shown in  FIG. 2 . Then, as shown in  FIG. 3 , the mirror unit  70  is moved to an inspection position so that the sample mounting portion  35  can be positioned inside the mirror unit  70  so that the sample  90  can be placed on the same line as the electron through hole  71  in the height direction. To move the mirror unit  70 , the optical fiber  40  extended to the exterior of the electron microscope is controlled in the holder grip  11  so that the coupler  50  coupled to the optical fiber  40  can move with respect to the frame  20  in the axial direction. 
         [0040]    Then, the electron microscope is controlled to emit the electron beam toward the electron through hole  71 . The electron beam passes through the electron through hole  71  and then collides with the sample  90 . Thus, light is emitted while electrons move between energy band gaps of the sample  90 . 
         [0041]      FIG. 9  is an optical concept view for explaining a light condensing mechanism of the holder device for the electron microscope according to an exemplary embodiment. As shown in  FIG. 9 , cathodoluminescence emitted from a sample  90  is reflected from the upper and lower mirror surfaces  76  and  78  surrounding the sample  90  toward the lens  60 . Then, the lens  60  condenses the cathodoluminescence on the end surface of the optical fiber  40 . Thus, the cathodoluminescence emitted from the sample  90  is collected in the optical fiber  40 . The optical fiber  40  transmits the collected cathodoluminescence to an external analysis device. 
         [0042]    Further, if various experiments for an X-ray analysis, an analysis using secondary electrons and back electrons  2 , etc. are additionally needed, the mirror unit  70  is moved to the position separated from the sample mounting portion  35  as shown in  FIG. 2  and then the experiments are carried out.