Patent Publication Number: US-7902505-B2

Title: Charged particle beam apparatus

Description:
RELATED APPLICATIONS 
     This application is a Continuation of U.S. application Ser. No. 11/527,522, filed Sep. 27, 2006, now U.S. Pat. No. 7,442,928 claiming priority of Japanese Application No. 2005-284733, filed Sep. 29, 2005, the entire contents of each of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a charged particle beam apparatus for identifying a predetermined position in a sample having a repeated pattern. 
     2. Description of the Related Art 
     In the analysis of a defect or failure in a semiconductor memory, it is required to identify a memory cell which has the defect or failure. Conventionally, a scanning electron microscope (SEM) has been used in order to identify the memory cell which has the defect or failure. Namely, a sample stage is displaced with a pitch corresponding to the pitch between the memory cells while making a visual inspection of the SEM image of the sample, thereby counting the memory cells from an edge of the sample. 
     In recent years, in accompaniment with the fine miniaturization of semiconductor memory devices, each memory cell has been becoming tremendously smaller and smaller in size. Accurately identifying a specific memory cell requires implementation of the stage displacement accuracy at the submicron level. The conventional scanning electron microscope, however, has not had a sample stage mechanism whose accuracy is so high as to be able to identify the memory cell. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an apparatus which makes it possible to count memory cells, and to detect the position of a specific memory cell without using a high-accuracy sample stage mechanism. 
     In a charged particle beam apparatus according to the present invention, when a sample includes repeated memory cells, a scale pattern corresponding to the repeated memory cells is created. Next, the scale pattern created is superimposed on the image of the repeated memory cells of the sample, thereby identifying a destination memory cell. 
     Moreover, in the charged particle beam apparatus according to the present invention, when the sample includes the repeated memory cells, the position of the destination memory cell is identified from a disposition of the repeated memory cells of the sample. 
     Furthermore, in the charged particle beam apparatus according to the present invention, a zoom image is generated by a combination of a zoom based on beam deflection function and a zoom based on software. Then, the image shift is performed by software without displacing the sample stage. 
     According to the present invention, it becomes possible to count memory cells, and to detect the position of a specific memory cell without using a high-accuracy sample stage mechanism. 
     Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram for illustrating a first embodiment of a charged particle beam apparatus according to the present invention; 
         FIG. 2  is a detailed diagram of a FIB column of the focused ion beam apparatus according to the present invention; 
         FIG. 3  is a configuration diagram of a control apparatus of the focused ion beam apparatus according to the present invention; 
         FIG. 4  is a diagram for explaining part of a deflection control system and an image generation system of the control apparatus in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 5  is a diagram for illustrating an embodiment of an input screen of a display apparatus in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 6A  to  FIG. 6D  are diagrams for explaining a method for identifying a memory cell and a method for performing a marker machining in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 7A  to  FIG. 7D  are diagrams for explaining the method for identifying a memory cell and the method for performing the marker machining in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 8  is a diagram for explaining the method for identifying a memory cell and the method for performing the marker machining in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 9  is a diagram for illustrating a second embodiment of the charged particle beam apparatus according to the present invention; 
         FIG. 10  is a diagram for illustrating an embodiment of the input screen of the display apparatus in the first embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 11A  to  FIG. 11D  are diagrams for explaining the method for identifying a memory cell and the method for performing the marker machining in a second embodiment of the focused ion beam apparatus according to the present invention; 
         FIG. 12  is a diagram for illustrating a third embodiment of the charged particle beam apparatus according to the present invention; 
         FIG. 13  is a diagram for illustrating a fourth embodiment of the charged particle beam apparatus according to the present invention; 
         FIG. 14  is a diagram for illustrating a flow of the processing in the fourth embodiment of the charged particle beam apparatus according to the present invention; 
         FIG. 15  is a diagram for illustrating a fifth embodiment of the charged particle beam apparatus according to the present invention; and 
         FIG. 16A  and  FIG. 16B  are diagrams for illustrating a flow of the CAD navigation processing in the fifth embodiment of the charged particle beam apparatus according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a diagram for illustrating the schematic configuration of a charged particle beam apparatus according to the present invention. The charged particle beam apparatus of the present embodiment is a focused ion beam apparatus. The focused ion beam apparatus includes the following configuration components: A FIB column  10  for generating a focused ion beam  120  so as to irradiate a sample  111  with the focused ion beam  120 , a detector  112  for detecting secondary electrons  121  emitted from the sample  111 , a control apparatus  20 , an image generation and machining unit  30 , an input apparatus  41 , and a display apparatus  42 . The image generation and machining unit  30  inputs a secondary-electron beam signal from the detector  112  to generate a scanning-ion-microscope (: SIM) image, thereby machining a marker on the sample  111 . The image generation and machining unit  30  includes a hardware-based zoom unit  31  for performing a hardware-based zoom, a software-based zoom and shift unit  32  for performing a software-based zoom and a software-based shift, a scale-pattern and mark-pattern unit  33  for performing the generation and display of a scale pattern and a mark pattern, and a marker machining unit  34  for machining the marker on the sample  111 . The hardware-based zoom means the execution of a zoom by a beam deflection function. The software-based zoom means the scale-up of an image in a digital manner using an image processing. The software-based shift means the displacement of an image in a digital manner using an image processing, i.e., displacing the image without displacing the sample stage. 
     Implementing the software-based zoom and the software-based shift requires that at least the beam deflection point resolution be larger than the image display resolution. In the present embodiment, the beam deflection point resolution is equal to 4096×4096 points, and the image display resolution is equal to 512×512 pixels. Accordingly, it becomes possible to implement the software-based zoom which exhibits an eight-time magnification at the maximum. 
     The image generation and machining unit  30  may also be a computer  201 , or a program to be executed by the computer. 
       FIG. 2  is a detailed diagram of the FIB column  10  of the focused ion beam apparatus according to the present invention. The FIB column  10  includes the following configuration components: A liquid-metal ion source emitter  100 , an extraction electrode  101 , a condenser lens  102 , a variable aperture  103 , an aligner/stigmator  104 , a blanker  105 , a blanking aperture  106 , a Faraday cup  107 , a deflector  108 , and an objective lens  109 . The focused ion beam apparatus further includes the detector  112  for detecting the secondary electrons  121  emitted from the sample  111 , a deposition gas source  113  for feeding a gas to the proximity to the sample surface, and a manipulator  115  for picking up a microscopic sample. 
     The ions from the liquid-metal ion source emitter  100  are extracted by the extraction electrode  101 , then being focused on the sample  111  by the condenser lens  102  and the objective lens  109 . In a blanking operation by the blanker  105 , the ion beam is injected into the Faraday cup  107 . 
     The focused ion beam apparatus of the present embodiment is equipped with the deposition gas source  113  and the manipulator  115 . This configuration allows a microscopic sample fragment to be extracted out of a local area of the sample by using the micro-sampling method. 
     Referring to  FIG. 3 , the explanation will be given below concerning an embodiment of the control apparatus  20  of the charged particle beam apparatus according to the present invention. The control apparatus  20  includes the following configuration components: A high-voltage power-supply  203 , an aperture control power-supply  204 , an aligner/stigmator control power-supply  205 , a beam-current measurement amplifier  206 , a blanking control power-supply  207 , a deflection amplifier  208 , a preamplifier  209 , a stage control power-supply  210 , a scanner  211 , an image memory  212 , an evacuation control power-supply  213 , a gas control power-supply  214 , and a manipulator control power-supply  215 . The respective control power-supplies are controlled in a centralized manner by the computer  201  via a control bus  202 . 
     The high-voltage power-supply  203  applies high voltages to the ion source emitter  100 , the extraction electrode  101 , the condenser lens  102 , and the objective lens  109 . The aperture control power-supply  204  controls the variable aperture  103 , thereby selecting a desired aperture diameter. A small-diameter aperture is selected at the time of image observation, and a large-diameter aperture is selected when performing a large-area machining. The aligner/stigmator control power-supply  205  controls an octo-pole deflector electrode voltage for the aligner/stigmator  104 , thereby performing electrical axis alignment and astigmatic correction. The beam-current measurement amplifier  206  measures the beam current which is flown into the Faraday cup  107  at the time of blanking. The blanking control power-supply  207  drives a blanking electrode of the blanker  105 , thereby performing the beam blanking. 
     The deflection amplifier  208  inputs a scanning signal from the scanner  211 , then driving the deflector  108 , i.e., an octo-pole and two-stage electrostatic deflector. The preamplifier  209  converts the signal from the detector  112  into a luminance voltage signal, then converting this signal into digital values, and writing the digital values into the image memory  212 . An image stored into the image memory  212  is displayed on the display apparatus  42 . 
     The gas control power-supply  214  performs temperature control over the gas source  113  and its valve open/close control. The manipulator control power-supply  215  performs fine-motion control over the manipulator  115 , and its touch-detection control with the sample. 
       FIG. 4  is a diagram for explaining part of a deflection control system and an image generation system of the control apparatus  20  of the charged particle beam apparatus according to the present invention. The scanner  211  includes X-direction and Y-direction 9-bit beam scanning counters  61 ,  62  and DA converters  69 ,  70 . The digital scanning signals xd, yd from the counters  61 ,  62  are converted into analogue scanning signals xa, ya by the DA converters  69 ,  70 , then being outputted to the deflection amplifier  208 . 
     The preamplifier  209  includes an AD converter  71  for applying an AD conversion to the analogue secondary-electron signal from the detector  112 . The digital secondary-electron signal from the AD converter  71  is stored into the image memory  212  together with the digital scanning signals xd, yd from the counters  61 ,  62 . Setting up synchronization between the image writing and the scanning allows the sample&#39;s microscope image to be formed in the image memory  212 . In this way, the 512-pixel×512-pixel image turns out to be stored into the image memory  212 . 
       FIG. 5  illustrates an embodiment of a screen  500  of the display apparatus  42  in the first embodiment of the charged particle beam apparatus according to the present invention. On the upper side of this screen, there are provided a direction selection field  501 , a cell-size input field  502 , a scale-length specification field  503 , a start-cell specification field  504 , and a set button  505 . The direction selection field  501 , which is provided for selecting the direction of a scale to be created, makes it possible to select either the horizontal direction (i.e., Horizontal) or the vertical direction (i.e., Vertical). The cell-size input field  502 , which is provided for specifying the size of each of repeated memory cells, makes it possible to input the sizes of each cell in the X and Y directions. The unit for the sizes is μm. The scale-length specification field  503  is provided for specifying the cell number of a scale to be created at one time. The start-cell specification field  504  is provided for specifying the start number of the cell-number value to be written along with the scale. The set button  505  is provided for creating a scale corresponding to the data selected or inputted, and displaying the scale in such a manner that the scale is superimposed on the image of the repeated memory cells. 
     On the lower side of this screen, there are provided a displacement array button  506 , a resize button  507 , a zoom selection field  508 , an image shift button  509 , an image acquisition button  510 , a clear button  511 , an all-clear button  512 , and a close button  513 . The displacement array button  506  is provided for performing the position adjustment of a scale created. The resize button  507  is provided for performing the resizing of the scale created. 
     The zoom selection field  508  is provided for specifying the zoom ratio by a beam deflection function. The image shift button  509  is provided for displacing the image in a software-based manner, i.e., shifting the image in a digital manner without displacing the sample stage. Pressing the image shift button  509  shifts the image in such a manner that the front end of the created scale will be displayed at the end of the displayed image. This permits a scale to be created next to be included within the displayed image. The image acquisition button  510  is provided for newly acquiring the sample image by scanning the beam with the present zoom ratio and the present shift position. Namely, the button  510  is provided for acquiring the sample image by the hardware-based zoom. The clear button  511  is provided for deleting the created scale. The all-clear button  512  is provided for deleting all the created scales. The close button  513  is provided for terminating this screen. 
     In the present embodiment, although the image display resolution of the screen of the display apparatus  42  is equal to 512×512 pixels, the beam deflection point resolution is equal to 4096×4096 points. Accordingly, it becomes possible to implement the hardware-based zoom which exhibits an eight-time magnification at the maximum. When the zoom ratio is equal to 1, scaling-down the 4096×4096 beam deflection points to the 512×512 pixels requires that the 4096×4096 beam deflection points be thinned out into its one-eighth by the beam deflection function. Meanwhile, when the zoom ratio is equal to 8, the 4096×4096 beam deflection points need not be scaled-down. In substitution therefor, the one-eighth part of the 4096×4096 beam deflection points is used thereby to define and configure the 512×512 pixels. 
     When the zoom ratio is equal to 8, only the part of the scaled-up image is displayed on the screen of the display apparatus  42 . As a result, displaying the other part of the scaled-up image necessitates shifting of the scaled-up image. In the present embodiment, an image is shifted by the image processing, i.e., in a software-based manner. Consequently, displacing the sample stage is unnecessary for shifting the image. 
     Next, referring to  FIG. 6A  to  FIG. 6D  and  FIG. 7A  to  FIG. 7D , the explanation will be given below concerning a method for identifying a cell. Here, the explanation will be given regarding the following case: Namely, defining the upper-left end of repeated cells as a start-point cell, a cell will be identified which is the 20th cell in the horizontal direction and right direction, and also which is the 20th cell in the vertical direction and down direction. 
       FIG. 6A  to  FIG. 6D  and  FIG. 7A  to  FIG. 7D  illustrate examples of the screen of the display apparatus  42 . This screen  600  includes an image display area  601 , a longitudinal slide bar  602 , and a transverse slide bar  603 . The image display area  601  displays the image of a sample as the 512-pixel×512-pixel image. The longitudinal slide bar  602  and the transverse slide bar  603  are used for displacing in a software-based manner the image displayed on the image display area  601 . The length of each black indicator included in the longitudinal slide bar  602  and the transverse slide bar  603  indicates the zoom ratio. Also, the position of each black indicator indicates at which position of the entire image an area displayed now on the image display area  601  exists. When the zoom ratio is equal to 1, each black indicator has extended along the entire area of each slide bar. Accordingly, when the zoom ratio is equal to 1, the whole area of the sample image is displayed on the image display area  601 . Consequently, the sample image at this time cannot be displaced by the longitudinal slide bar  602  and the transverse slide bar  603 . 
     The image display area  601  in  FIG. 6A  displays the image of the repeated cells whose zoom ratio is equal to 1. This is a case of selecting the zoom ratio as being 1 in the zoom selection field  508 , and pressing the image acquisition button  510 . Each black indicator has extended along the entire area of each slide bar. The image display area  601  in  FIG. 6B  displays the image of the repeated cells whose zoom ratio is equal to 2. This is a case of selecting the zoom ratio as being 2 in the zoom selection field  508 . The image whose zoom ratio is equal to 2 is acquired in a software-based manner. Each black indicator has extended along the one-half area of each slide bar. Displacing each black indicator makes it possible to shift the image in the up-and-down and right-to-left directions. The image display area  601  in  FIG. 6C  displays the image of the repeated cells whose zoom ratio is equal to 4. This is a case of selecting the zoom ratio as being 4 in the zoom selection field  508 . The image whose zoom ratio is equal to 4 is acquired in a software-based manner. Each black indicator has extended along the one-fourth area of each slide bar. Displacing each black indicator makes it possible to shift the image in the up-and-down and right-to-left directions. In the image which is scaled-up to the four-time magnification in a software-based manner, the outline of each of the repeated cells is not clear. Next, pressing the image acquisition button  510  makes it possible to acquire the image illustrated in  FIG. 6D . Pressing the image acquisition button  510  results in the execution of the hardware-based zoom, i.e., the zoom by the beam deflection function. Consequently, the image of each cell illustrated in  FIG. 6D  is clearer than that of each cell illustrated in  FIG. 6C . 
     The image display area  601  in  FIG. 6D  displays a state where a first scale  610  is superimposed on the image of the repeated cells whose zoom ratio is equal to 4. Here, the image display area  601  displays a case of selecting the horizontal direction in the direction selection field  501 , inputting the cell size of 1 μm 1 μm in the cell-size input field  502 , inputting 10, i.e., the number of the cells as the scale length, in the scale-length specification field  503 , inputting 1, i.e., the 1st cell, in the start-cell specification field  504 , and pressing the set button  505 . 
     The scale  610  has a configuration that 10 units of 1-μm-longitudinal×1-μm-transverse squares are arranged in line. Each of the squares is the same as each of the repeated cells in configuration. At first, this scale  610  is not matched to the outline of the repeated cells. Namely, the size and position of the scale  610  are displayed in a manner of differing from the size and position of the repeated cells. Operating the displacement array button  506  performs the position alignment, and operating the resize button  507  performs the size alignment. Performing the position alignment and the size alignment in this way allows the scale  610  to be matched to the repeated cells as is illustrated in  FIG. 6D . The start end square of the scale  610  is located in a manner of being matched to the upper-left end cell of the repeated cells. On the right end square of the scale  610 , “10”, i.e., the number of the counted cells as the scale length, is displayed. 
       FIG. 7A  illustrates a state where a next scale  611  is displayed in such a manner that the next scale  611  extends from the 10th square of the scale  610 . The scanning-ion-microscope image is shifted in the horizontal direction so that the 10th square of the scale  610  is located at the upper-left end of the image display area  601 . Although shifting the image is implemented by pressing the image shift button  509 , it may also be implemented by operating the transverse slide bar  603 . On the right end square of the scale  611 , “20”, i.e., the number of the counted cells, is displayed. This shows that the twenty cells have been counted in the horizontal direction. 
       FIG. 7B  illustrates a state where a scale  612  in the longitudinal direction is displayed in such a manner that the scale  612  extends from the 20th square of the scale  611 . Here, the image display area  601  displays a case of selecting the longitudinal direction in the direction selection field  501 , inputting the cell size of 1 μm×1 μm in the cell-size input field  502 , inputting  10 , i.e., the number of the cells as the scale length, in the scale-length specification field  503 , inputting  10 , i.e., the 10th cell, in the start-cell specification field  504 , and pressing the set button  505 . At the right of the lower end square of the scale  612 , “10”, i.e., the number of the counted cells specified in the start-cell specification field  504 , is displayed. 
       FIG. 7C  illustrates a state where a next scale  613  is displayed in such a manner that the next scale  613  extends from the 10th square of the scale  612 . The scanning-ion-microscope image is shifted in the longitudinal direction so that the 10th square of the scale  612  is located at the upper-right end of the image display area  601 . Although shifting the image is implemented by pressing the image shift button  509 , it may also be implemented by operating the longitudinal slide bar  602 . At the right of the lower end square of the scale  613 , “20”, i.e., the number of the counted cells, is displayed. This shows that the twenty cells have been counted in the longitudinal direction. In this way, the cell existing at the above-described destination position (20, 20) is attained and reached. 
       FIG. 7D  illustrates a state where the scanning-ion-microscope image is shifted so that the cell existing at the destination position (20, 20) is located at the center of the image display area  601 . Shifting the image is executed in a software-based manner, i.e., without displacing the sample stage. A circle-shaped mark pattern  614  is displayed on the square of the destination position (20, 20). This mark pattern  614  makes it possible to visually recognize the position of the destination cell. 
     The scales  610 ,  611 ,  612 , and  613  and the mark pattern  614  are just geometrical graphics formed on the screen, and thus are not physically formed on the sample surface by using the scanning ion beam. As a consequence, in the present embodiment, it becomes possible to identify the destination cell with no damage caused onto the sample surface. 
       FIG. 8  illustrates a state where a cross-shaped marker  615  is formed in the surroundings of the destination cell. Forming the marker  615  in this way allows the destination cell to be easily identified when observing this sample by using some other observation apparatus. The machining of the marker  615  may be a removal machining which takes advantage of the sputtering phenomenon based on a local irradiation with the focused ion beam. The machining of the marker  615  may also be a machining which takes advantage of focused-ion-beam-assisted deposition or focused-ion-beam-assisted etching in a gas atmosphere. Also, it can be assumed that the cell around which the marker  615  is formed will be analyzed by being subjected to a sampling. Consequently, a focused-ion-beam-assisted deposition film may be formed as a protection film on the upper portion of this cell. Also, it is possible to divert this protection film itself as the mark. 
       FIG. 9  is a diagram for illustrating a second embodiment of the charged particle beam apparatus according to the present invention. The charged particle beam apparatus of the present embodiment is a focused ion beam apparatus. In comparison with the first embodiment in  FIG. 1 , the focused ion beam apparatus of the present embodiment differs therefrom in the image generation and machining unit  30 . The image generation and machining unit  30  of the present embodiment includes the hardware-based zoom unit  31  for performing the hardware-based zoom, the software-based zoom and shift unit  32  for performing the software-based zoom and the software-based shift, an alignment unit  35  for performing an alignment between virtually set disposition information on the cells and the scanning-ion-microscope image, and a mark pattern unit  36  for performing the generation and display of the mark pattern, and the marker machining unit  34  for machining the marker on the sample  111 . In order to implement the software-based zoom and the software-based shift, the beam deflection point resolution is larger than the image display resolution. In the present embodiment, the beam deflection point resolution is equal to 4096×4096 points, and the image display resolution is equal to 512×512 pixels. Accordingly, it becomes possible to implement the software-based zoom which exhibits an eight-time magnification at the maximum. 
       FIG. 10  illustrates an embodiment of a screen  1000  of the display apparatus  42  in the second embodiment of the charged particle beam apparatus according to the present invention. On the upper side of this screen, there are provided a cell-disposition input field  1001 , first to third alignment-position input fields  1002   a  to  1002   c , and three lock buttons  1003   a  to  1003   c , and a clear button  1004 . 
     The cell-disposition input field  1001  is provided for inputting the disposition number of the cells which belong to the sample. The first to third alignment-position input fields  1002   a  to  1002   c  are provided for inputting three positions for the alignment. The three lock buttons  1003   a  to  1003   c  are provided for registering the input values into the first to third alignment-position input fields  1002   a  to  1002   c . The clear button  1004  is provided for clearing the input values. The cell-disposition number is inputted into the cell-disposition input field  1001 , and the three alignment positions are inputted into the first to third alignment-position input fields  1002   a  to  1002   c , then pressing the lock buttons  1003   a  to  1003   c . This operation causes the alignment to be performed at the three alignment positions. 
     On the lower side of this screen, there are provided a destination-cell coordinate input field  1005 , a clear button  1006 , a mark button  1007 , and a close button  1008 . The destination-cell coordinate input field  1005  is provided for inputting the coordinate of a destination cell. The clear button  1006  is provided for clearing the input value. The mark button  1007  is provided for generating the mark pattern in the surroundings of the destination cell. After the alignment at the three alignment positions has been terminated, the coordinate of the destination cell is inputted into the destination-cell coordinate input field  1005 , then pressing the mark button  1007 . This operation causes the mark pattern to be displayed in the surroundings of the destination cell. 
     Next, referring to  FIG. 11A  to  FIG. 11D , the explanation will be given below concerning a method for identifying a cell. Here, the explanation will be given regarding the following case: Namely, defining the upper-left end of repeated cells as a start-point cell, a cell will be identified which is the 30th cell in the horizontal direction and right direction, and also which is the 30th cell in the vertical direction and down direction. It is assumed that the number of the repeated cells has been already known, and that all the cells exist within the beam deflection area. Namely, it is assumed that all the cells can be irradiated with the beam without displacing the sample stage. In recent years, there has been a significant increase in the storage capacity of such apparatuses as the semiconductor memory. The memory cells, however, are partitioned with a minimum unit which is referred to as “mat”. In accompaniment with the fine miniaturization of the semiconductor memory devices, this mat has been becoming a size which permits the mat to be easily included within the beam deflection area. 
       FIG. 11A  to  FIG. 11D  illustrate examples of the screen of the display apparatus  42 . This screen  1100  includes an image display area  1101 , a longitudinal slide bar  1102 , and a transverse slide bar  1103 . The image display area  1101  displays the image of a sample as the 512-pixel×512-pixel image. As is the case with  FIG. 6C , the image display area  1101  displays the image of the repeated cells whose zoom ratio is equal to 4. Each black indicator has extended along the one-fourth area of each slide bar. Displacing each black indicator makes it possible to shift the image in the up-and-down and right-to-left directions. 
       FIG. 11A  illustrates a case of inputting the cell-disposition number 100×100 in the cell-disposition input field  1001 , and inputting a first position (1, 1) of the cells in the first alignment-position input field  1002   a . The first position (1, 1) of the cells is located at the upper-left end of the image display area  1101 , and a cursor  1111  is displayed there.  FIG. 11B  illustrates a case of inputting a second position (1, 30) of the cells in the second alignment-position input field  1002   b . The second position (1, 30) of the cells is located at the upper-right end of the image display area  1101 , and the cursor  1111  is displayed there.  FIG. 11C  illustrates a case of inputting a third position (30, 30) of the cells in the third alignment-position input field  1002   c . The third position (30, 30) of the cells is the position of the destination cell. The destination cell is located at the lower-right end of the image display area  1101 , and the cursor  1111  is displayed there. 
     In this way, in the present embodiment, the upper-left end of the cells is set as the first position. Next, the position resulting from displacing the first position in the right direction by the amount of the X coordinate of the destination cell is set as the second position. Moreover, the position resulting from displacing the second position in the down direction by the amount of Y coordinate of the destination cell is set as the third position. As a result of this operation, the third position becomes the position of the destination cell. The image generation and machining unit  30  identifies the destination cell on the virtual cell disposition. 
       FIG. 11D  illustrates a state where a circle-shaped mark pattern  1112  is displayed on the position (30, 30) of the destination cell. This is a case of inputting the position (30, 30) of the destination cell into the destination-cell coordinate input field  1005 . On the virtual cell disposition, the mark pattern  1112  is displayed on the position (30, 30) of the destination cell. 
     Pressing the mark button  1007  causes a marker  1113  to be generated in the surroundings of the destination cell. As described earlier, the machining of the marker  615  may be the removal machining which takes advantage of the sputtering phenomenon based on the local irradiation with the focused ion beam. 
     In the present embodiment, the coordinate of the destination cell has been specified on the screen  1000  in  FIG. 10 . It is also possible, however, that information such as file bit map is acquired from a defect inspection system, and the coordinate of the destination cell is extracted out of this information so as to be manipulated and taken advantage of. 
       FIG. 12  is a diagram for illustrating a third embodiment of the charged particle beam apparatus according to the present invention. The charged particle beam apparatus of the present embodiment includes a SEM column  11  for generating a focused electron beam  120  so as to irradiate the sample  111  with the focused electron beam  120 . In comparison with the first and second embodiments illustrated in  FIG. 1  and  FIG. 9  respectively, the present embodiment differs therefrom in the point that the electron beam is used as the charged particle beam. In the case of the electron beam, the execution of even a long-time irradiation with the electron beam causes no damage onto the surface of the sample  111 . When performing the marker machining on the sample surface by using the electron beam, a contamination may be deposited thereon by performing the long-time electron beam irradiation onto a local area thereof within an atmosphere whose vacuum level is comparatively low. In the present embodiment, however, a protection film has been formed on the sample surface by feeding a tungsten hexa carbonyl gas thereto from the deposition gas source  113 . Then, this protection film has been irradiated with the focused electron beam, thereby forming the marker. The control over the gas source  113  has been performed from a deposition control unit inside the control apparatus. 
       FIG. 13  is a diagram for illustrating a fourth embodiment of the charged particle beam apparatus according to the present invention. The charged particle beam apparatus of the present embodiment includes the FIB column  10  for generating the focused ion beam so as to irradiate the sample  111  with the focused ion beam, and the SEM column  11  for generating the electron beam so as to irradiate the sample  111  with the electron beam. In the present embodiment, either or both of the focused ion beam and the electron beam will be used. 
     Next, referring to  FIG. 14  and using the fourth embodiment of the charged particle beam apparatus according to the present invention, the explanation will be given below concerning a method for identifying a cell located at a predetermined position, and performing the sampling of this cell. At a step S 101 , the cell count is performed using the scanning-electron-microscope (: SEM) image, thereby performing the identification of a destination cell. The processing at the step S 101  is basically the same as the first and second embodiments illustrated in  FIG. 1  and  FIG. 9  respectively. At a step S 102 , the surface of the sample  111  is irradiated with the electron beam while feeding a gas thereto from the deposition gas source  113 . This processing forms a protection film on the destination cell. In the present embodiment, this protection film has a function as the marker for identifying the destination cell. At a step S 103 , a microscopic sample fragment including the destination cell is extracted based on the micro-sampling method using the focused ion beam. The sample  111  is taken out of a sample chamber, then introducing a carrier  116  into the sample chamber and locating the carrier  116  on the beam&#39;s optical axis. The microscopic sample fragment is fixed on this carrier  116  via the deposition film. At a step S 104 , a thin-film machining of the microscopic sample fragment bonded to the carrier  116  is performed using the focused ion beam. The carrier  116  is tilted so that the electron beam will pass through this resultant thin-film fragment in a manner of being perpendicular thereto. At a step S 105 , the electron beam is scanned on the thin-film fragment, and the electron beam which has passed through the thin-film fragment is detected by a STEM detector  117 . From the output of the STEM detector  117 , the scanning-transmission-electron-microscope (: STEM) image of the sample fragment is acquired. This STEM image permits acquisition of defect information within the destination memory cell. 
     In the charged particle beam apparatus of the present embodiment, there are simultaneously provided a large-sized sample targeted stage usually used in the SEM and a side-entry stage usually used in the TEM. Also, the STEM detector  117  is provided within the large-sized sample targeted stage. According to the present embodiment, the electron beam is taken advantage of. This feature allows implementation of the cell count which causes little damage to the sample, and also makes it possible to form the protection film on the upper portion of the destination cell (This is effective when the defect exists in the proximity to the sample surface). Also, there are simultaneously provided the FIB column  10 , the deposition gas source  113 , the manipulator  115 , and the STEM detector  117 . As a result, it becomes possible to carry out the micro sampling inside one and the same sample chamber. This feature allows implementation of the high space-resolution STEM observation after the thin-film machining. Consequently, it becomes possible to perform at a high speed the operations ranging from the defect&#39;s position search to the high-resolution observation without exposing the sample to the atmosphere. 
     In the present embodiment, the use of the FIB column  10 , the deposition gas source  113 , and the manipulator  115  allows implementation of the micro sampling. It is self-evident, however, that the use of the manipulator  115  allows implementation of the sampling of the microscopic area including the identified cell in the first and second embodiments of the charged particle beam apparatus as well. In this case, there exists an advantage of being capable of performing at a high speed the operations ranging from the defect&#39;s position search to the sampling with the use of the single apparatus. 
       FIG. 15  illustrates a fifth embodiment of the charged particle beam apparatus according to the present invention. The present embodiment results from connecting a CAD navigation system  700  for performing the CAD navigation to the charged particle beam apparatus of the fourth embodiment illustrated in  FIG. 13 . The CAD navigation system  700  is connected to a CAD information database  701  for storing the CAD information and a device defect-coordinate information database  702  for storing the device defect-coordinate information. The device defect-coordinate information is defect-coordinate information such as fail bit map. The general utilization methodology for the CAD navigation is as follows: 
     (1) The sample is introduced into the charged particle beam apparatus. 
     (2) By displacing the sample stage, an alignment is performed between feature points (usually, three points positioned away from each other) of the sample and the CAD layout information. 
     (3) A destination location (e.g., a specific cell) is specified on the CAD layout. 
     (4) The sample stage is displaced to the specified place, thereby identifying the destination location. 
     According to this methodology, it is required to displace the sample stage. Accordingly, mechanical positioning accuracy of the sample stage determines specified accuracy of the destination location. If the sample pattern has a feature, and thus if a fine adjustment can be performed when the CAD layout pattern is superimposed on the sample pattern, it is possible to correct error amount of the stage displacement to some extent by making the visual inspection. In repeated patterns such as the memory cells, however, this type of correction is difficult to perform. Consequently, it has been long considered that identifying a memory cell absolutely necessitates the employment of a sample stage having an exceedingly high position accuracy. 
     In the present embodiment, the alignment method of the second embodiment according to the present invention illustrated in  FIG. 9  is applied to the CAD navigation system  700 . Namely, using a digital zoom-up and shift function, the alignment is performed between the CAD layout information and a sample image within the beam deflection area. In this away, the detailed CAD navigation within the beam deflection area has been made possible without displacing the sample stage. 
     Next, referring to  FIG. 16A  and  FIG. 16B , the explanation will be given below concerning a method of the present embodiment.  FIG. 16A  and  FIG. 16B  illustrate examples of the screen of the display apparatus. This screen  1500  includes an image display area  1501 , a longitudinal slide bar  1502 , and a transverse slide bar  1503 . The image display area  1501  displays the image of a sample as the 512-pixel×512-pixel image. The image display area  1501  in  FIG. 16A  displays CAD layout patterns and sample images before the alignment. Before the alignment, the CAD layout patterns in solid lines and the sample images in dashed lines deviate from each other. The image display area  1501  in  FIG. 16B  displays the CAD layout patterns and the sample images after the alignment. After the alignment, the CAD layout patterns and the sample images are located in a manner of being matched to each other. Namely, the CAD layout patterns are superimposed on the sample images in a manner of being matched thereto. After the alignment, the CAD layout patterns and the sample images displace in a state of being overlapped with each other. The CAD navigation system  700  extracts the memory-cell coordinate of a defect from the device defect-coordinate information database  702 , then displaying a mark pattern  1511  for the defect on the CAD layout patterns. Accordingly, identifying the destination cell (in this case, the defective cell) can be carried out with a high accuracy. In the present embodiment, the explanation has been given concerning the identification of a cell. It is self-evident, however, that the methodology taking advantage of the CAD navigation system allows not only the search for a cell, but also the search for a general destination location. 
     According to the present invention, the cell count, which is effective for the failure analysis of a semiconductor in particular, can be carried out with a high accuracy and at a high speed. The mechanical movement of the stage displacement is unnecessary during the cell count. This feature makes it possible to ensure the high position accuracy, and thus makes it possible to ensure the high count accuracy. Since the high stage-displacement accuracy is unnecessary, there exists an advantage of being capable of implement the functions at a low cost. 
     So far, the explanation has been given concerning the above-described embodiments of the present invention. It will be understood by those who are skilled in the art, however, that the present invention is not limited to these embodiments, and that the various modifications can be made within the scope of the present invention disclosed in the following appended claims.