Patent Publication Number: US-7725278-B2

Title: Method for failure analysis and system for failure analysis

Description:
CROSS-REFERENCES 
   This is a continuation application of U.S. application Ser. No. 10/339,356, filed Jan. 10, 2003, now U.S. Pat. No. 7,200,506 now allowed. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a failure analysis technique for analyzing a failure of an electronic device or the like. 
   In fabrication of electronic devices such as a semiconductor memory typified by a dynamic random access memory (DRAM), a microprocessor, a semiconductor device such as a semiconductor laser, and a magnetic head, a high production yield is demanded. 
   Reduction in the product yield due to occurrence of a failure causes deterioration in profitability. Consequently, it is a big task to find a defect, a foreign matter, and poor processing as causes of a failure early and to take a countermeasure early. For example, at a manufacturing site of a semiconductor device, energies are put into early finding of a failure by a careful inspection and analysis of the cause of the failure. In a process of manufacturing actual electron devices using a wafer, a wafer in a process is inspected, the cause of an abnormal part such as a defect in a circuit pattern or a foreign matter is pursued, and a countermeasure is examined. 
   Usually, a high-resolution scanning electron microscope (hereinbelow, abbreviated as SEM) is used for observing a fine structure of a sample. As the packing density of a semiconductor increases, it is becoming impossible to observe an object with the resolution of the SEM, and a transmission electron microscope (hereinbelow, abbreviated as TEM) having a higher observation resolution is used in place of the SEM. 
   Preparation of a conventional sample for TEM accompanies a work of extracting a small piece from a sample substrate by cleavage, cutting, or the like. In the case where a sample substrate is a wafer, in most cases, the wafer has to be cut. 
   Recently, there is an example of using a processing method of irradiating a sample substrate with an ion beam and applying the action that particles constructing the sample substrate are discharged from the sample substrate by a sputtering action, that is, a focused ion beam (hereinbelow, abbreviated as FIB) process. 
   According to the method, first, a rectangular-shaped pellet having a thickness of sub-millimeters including an area to be observed is cut out from a sample substrate such as a wafer by using a dicer or the like. Subsequently, a part of the rectangular-shaped pellet is processed with an FIB into a thin film form, thereby obtaining a TEM sample. The feature of the FIB-processed sample for TEM observation is that a part of a sample piece is processed to a thin film having a thickness of about 100 nm so as to be observed by the TEM. Although the method enables a desired observation part to be positioned with precision of a micrometer level and observed, the wafer still has to be cut. 
   As described above, although the advantage of monitoring a result of a process during fabrication of a semiconductor device or the like is big from the viewpoint of yield management, a wafer is cut for preparing a sample and pieces of the wafer do not go to the following process but are discarded. Particularly, in recent years, the diameter of a wafer is increasing in order to lower the unit price of fabricating a semiconductor device. To be specific, the number of semiconductor devices which can be fabricated from one wafer is increased, thereby reducing the unit price. However, in other words, the price of a wafer increases and the number of semiconductor devices which are lost by discarding a wafer also increases. Therefore, the conventional inspection method including cutting of a wafer is very uneconomical. 
   Addressing the problem, there is a method capable of obtaining a sample without cutting a wafer. The method is disclosed in Japanese Patent Application Laid-Open No. 05-52721 (prior art 1). 
   According to the method, as shown in  FIGS. 2(   a ) to  2 ( g ), the posture of a specimen substrate  202  is kept so that the surface of the specimen substrate  202  is irradiated with an FIB  201  at the right angle, and a rectangular area in the surface of the specimen substrate  202  is scanned with the FIB  201 , thereby forming a rectangular hole  207  having a required depth in the surface of the sample ( FIG. 2(   a )). After that, the specimen substrate  202  is tilted and a bottom hole  208  is formed. The tilt angle of the specimen substrate  202  is changed by a specimen stage (not shown) ( FIG. 2(   b )). The posture of the specimen substrate  202  is changed to set the specimen substrate  202  so that the surface of the specimen substrate  202  becomes perpendicular to the FIB  201  again, and a trench  209  is formed ( FIG. 2(   c )). A manipulator (not shown) is driven to make the tip of a probe  203  at the end of the manipulator come into contact with a part to be extracted from the specimen substrate  202  ( FIG. 2(   d )). Subsequently, while supplying a deposition gas  205  from a gas nozzle  210 , an area including the tip portion of the probe  203  is locally irradiated with the FIB  201 , thereby forming an ion beam gas assisted deposition film  204 . The separation part in the specimen substrate  202  and the tip of the probe  203  which are in contact with each other are connected by the ion beam assisted deposition layer  204  ( FIG. 2(   e )). The remaining part is cut with the FIB  201  ( FIG. 2(   f )) and a micro-sample  206  as an extracted sample is cut out from the specimen substrate  202 . The cut-out micro-sample  206  is supported by the probe  203  connected ( FIG. 2(   g )). 
   The micro sample  206  is processed with the FIB  201  and an area to be observed is thinned, thereby obtaining a TEM sample (not shown). By introducing the micro-sample separated by the method into any of various analyzers, analysis can be conducted. 
   The above method is an example of extracting a micro-sample by a sample preparing apparatus and there is also a method of processing the shape of a sectional sample thin film, taking a specimen substrate from the sample preparing apparatus, and a sectional sample thin film is extracted by another mechanism in atmosphere. For example, a method is disclosed in “Material Research Society, Symposium Proceedings”, vol. 480, 1997, pp. 19 to 27 (prior art 2). Similarly, a method is disclosed in “Proceedings of the 22nd International Symposium for Testing and Failure Analysis, 18-22 Nov. 1996”, pp. 199 to 205 (prior art 3). 
   As shown in  FIG. 3(   a ), a section sample membrane  307  is formed while processing both sides of a target position on a wafer  308  in a stair shape with an FIB  301 . Subsequently, by tilting a sample stage, the angle formed between the FIB  301  and the surface of the specimen is changed and the specimen substrate is irradiated with the FIB  301 . As shown in  FIG. 3(   b ), the peripheral portion of the sample membrane  307  is cut away by using the FIB  301  and the sample membrane  307  is separated from the wafer  308 . The wafer  308  is taken out from an FIB apparatus, a glass stick is allowed to approach the process portion in the atmosphere, by using static electricity, the sample membrane  307  is absorbed by the glass stick and taken out from the wafer. The glass stick is moved to a mesh  309  and is either adsorbed by the mesh  309  by static electricity or disposed so that a surface to be processed faces a transparent adhesion member. In such a manner, without taking out the processed sample membrane in the system, even when most of the outer shape of the sample membrane is processed with an ion beam, by introducing the separated sample membrane into a TEM, analysis can be made. 
   A device manufacturing method in which a method similar to the prior art 1 for process management is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-156393 (prior art 4). 
   According to the method, process management is performed by a flow as shown in  FIG. 4 . A lot  401  is subjected to a process m 1 . After completion of the process m 1 , a predetermined number of wafers are selected as wafers  402  for inspection from the lot  401  and the other wafers  403  enter a standby mode. An area  404  for inspection in the selected wafer  402  for inspection is extracted as a micro-sample  405 . The wafer  402  for inspection from which the micro-sample  405  is extracted is put together with the other wafers  403  again and the wafers as a lot  401 A are subjected to the following process m 2 . The micro-sample  405  is processed so as to be used in one of analysis apparatus  406  and is transmitted to the analysis apparatus  406  where a target area in the micro-sample  405  is analyzed. A result of analysis is sent to a computer  407  and stored as a data base. The stored data base is transmitted as necessary via a communication path “h” to the process m 1  or m 2  and an instruction of a change in the process conditions or the like is given. 
   It is a big feature that a wafer is passed through paths a, b, c, and d from the process m 1  to the process m 2  and, during the paths, a micro sample for analysis is extracted. The number of sample substrates does not decrease for the inspection. The number of wafers in the lot  401  subjected to the process m 1  and the number of wafers in the lot  401  subjected to the process m 2  are the same. Consequently, there are no semiconductor devices which are lost due to cutting of the wafer. The total manufacture yield of semiconductor devices is increased and the manufacturing cost can be reduced. 
   In a failure analysis, when a failure mode is found by another tester such as a probe tester or an EB tester, a process causing the failure is clarified. The main target of the failure analysis in the invention is not only a failure existing only in a specific position in a wafer but also a failure existing in an entire face of a wafer or in an area of a certain range due to a process as a basic cause. 
   When a desired area is determined after a failure is detected by a test and a sample of observation and analysis is prepared by using means as employed in the prior arts 1, 2, and 3 in a procedure for failure analysis, the following problems remain. 
   Even if an abnormal part can be found in the observation sample prepared after device formation, there is a case that the process as a cause cannot be found in some cases. An example of the case will be described by referring to  FIGS. 5(   a ) to  5 ( d ). 
     FIG. 5(   a ) shows a cross section of a device on which a wiring process has been completed. In this example, formation of a metal line by a dual damascene process is shown. A metal line  501  is formed in a hole area for a line opened in an insulator layer  502 . At this time point, the metal line  501  is normally formed. In the following process of forming a cap layer  503 , heat treatment of about 300 to 400° C. is performed. In some cases, as shown in  FIG. 5(   b ), a defect area  504  is formed in a connection hole part in the metal line  501  due to the heat treatment. Even in the case where no failure occurs in  FIG. 5(   b ), there is a case that the defect area  504  occurs due to heat treatment of 400 to 500° C. at the time of forming an insulator layer  505  shown in  FIG. 5(   c ). 
   However, in the case where after completion of a final process, for example, breaking of wire or a high-resistance part is found by a probe test, an area to be observed is determined, a section is formed by a method as described in the prior arts 1 to 3, and a wiring process is examined, although the defect area  504  as shown in  FIG. 5(   d ) is observed, it is very difficult to clarify a process as a direct cause of the defect. Consequently, it is very important to clarify the cause from information which does not exert an influence by a later process. 
   An area to be monitored is preliminarily determined in the prior art 4, so that it is very effective for a process monitor for processing the area into a thin film or cross section to be observed. However, in order to use the area for failure analysis, the following problems occur. 
   In the failure analysis, an area for observation and analysis cannot be preliminarily specified. Consequently, if a micro-sample is extracted after completion of each process or a plurality of processes, and preliminarily processed as a TEM sample or the like, in the case where an area to be observed is determined in a later inspection and the area is different from the position of the prepared TEM sample, the possibility that the desired area has disappeared already is high, and the desired area cannot be observed. In the case of failure analysis, not only the position but also the direction of a face which is desired to be observed are also important. For example, in the case of a DRAM, there can be directions of sections parallel to and perpendicular to a word line, a face parallel to the surface of a specimen, and the like. In consideration of combinations of the positions and directions, the possibility that the position of the prepared TEM specimen (or position of other cross sections for observation and analysis) coincides with the desired area of failure analysis is very low. Consequently, in the failure analysis, it is necessary to process the area for observation and analysis which is determined on the basis of failure data obtained after an inspection. 
   SUMMARY OF THE INVENTION 
   The present invention has been achieved in consideration of the problems and its object is to provide a failure analysis technique capable of assuring a sample to be observed in an arbitrary observation-desired position determined later by a test in analysis of a failure in a device or the like. 
   In order to achieve the object, in the present invention, a micro-sample (or sample) is extracted and stored every after a predetermined process, and an additional process is performed on the micro-sample in an observation and analysis position determined on the basis of failure data derived later. The basic configuration of a system for failure analysis of the invention includes: an apparatus for micro-sample extraction (or an apparatus for sample extraction) for extracting, as a sample, a part of a substrate by using a processing beam each time an arbitrary process for forming a desired pattern on the substrate is finished; an apparatus for micro-sample storage (or an apparatus for sample storage) for storing the sample extracted; an apparatus for filing data of stored-sample for controlling management information regarding said sample as a data base; an apparatus for additional processing micro-sample (or an apparatus for additional processing sample) for processing the sample stored into a form which can be analyzed in response to a failure analysis request; and an apparatus for failure analysis for analyzing the sample processed. 
   Typical configuration examples of the system for failure analysis according to the invention will be described hereinbelow. 
   (1) A system for failure analysis includes: an apparatus for sample extraction for extracting, as a sample, a part of a substrate by an ion beam process each time an arbitrary process for forming a desired pattern on the substrate is finished and carrying the sample to a sample storage (or a micro-sample storage) for storing the sample; an apparatus for filing data of a stored sample for constructing a data base in which at least product name of the substrate, substrate name, and process name are associated with a storage position of the sample; an apparatus for sample storage for storing the sample storage in correspondence with the data base of the apparatus for filing data of the sample; an apparatus for additional processing micro-sample for taking out the selected sample from the sample storage and performing an additional process on the basis of additional process information; and an apparatus for failure analysis for analyzing the sample subjected to the additional process. 
   With the configuration, the cause of a failure which is found in a post process can be specified in a past process, so that the cause can be clarified efficiently. 
   (2) A system for failure analysis includes: an apparatus for sample extraction for extracting, as a sample, a part of a substrate by an ion beam process after each of two or more different processes for forming a desired circuit pattern on the substrate, and carrying the sample to a sample storage for storing the sample; an apparatus for filing data of a stored sample for constructing a data base in which at least product name of the substrate, substrate name, and process name are associated with a storage position of the sample; an apparatus for sample storage for storing the sample storage in accordance with the data base of the apparatus for filing data of the sample and selecting the sample corresponding to arbitrary product designation after completion of the product of the sample; an apparatus for additional processing micro-sample for taking out the sample selected in response to a failure analysis request and performing an additional process on the basis of additional process information; and an apparatus for failure analysis for analyzing the sample subjected to the additional process. 
   With the configuration, the cause of a failure in a failure device found after shipment of a product can be specified, and it is effective for explanation to the customer. 
   (3) The system for failure analysis with the configuration is characterized in that the apparatus for sample storage stores the sample storage in correspondence with the data base of the apparatus for filing data of stored-sample and selects the sample corresponding to the substrate determined as defective on the basis of a preset threshold in a failure inspection performed after at least two processes. Further, the system for failure analysis is characterized by further including an apparatus for filing a data base of failures for filing data of observation or analysis of the structure of the sample obtained from the apparatus for failure analysis as failure sample data in correspondence with a process parameter of the process. 
   Consequently, a process parameter in which a failure often occurs can be easily specified, so that the direction of setting a parameter by an advanced process control can be limited and the efficiency is increased. 
   (4) The system for failure analysis with the configuration is characterized by further including an ion beam control system for controlling the ion beam process, and the ion beam control system sets the size of the sample to be extracted to be larger than a repetition interval of circuit patterns formed on the substrate. 
   Consequently, failure analysis can be conducted in an arbitrary position in a device pattern by an additional process which is performed later. 
   (5) The system for failure analysis with the configuration is characterized in that the sample storage has a readable/writable IC memory storing a data base in which at least product name of the substrate, substrate name, and process name are associated with a storage position of the sample. 
   With the configuration, process history and the micro-sample position can be easily associated with each other. 
   (6) The system for failure analysis with the configuration is characterized in that the sample storage has a non-contact IC chip storing a numerical value by which a data base and the sample are associated with each other in a one-to-one corresponding manner, the data base in which at least product name of the substrate, substrate name, and process name are associated with a storage position of the sample. 
   With the configuration, the process history and the micro-sample can be easily associated with each other in a one-to-one manner. 
   (7) The system for failure analysis with the configuration is characterized in that the apparatus for sample extraction and the apparatus for sample storage, or the apparatus for sample storage and the apparatus for additional processing sample can be connected to each other so that the sample storage can be received/transmitted without being exposed to the atmosphere. 
   With the configuration, contamination of a micro-sample is suppressed and the reliability of failure analysis is improved. 
   (8) The system for failure analysis with the configuration is characterized in that the material for forming the sample storage is silicon. 
   With the configuration, contamination of a micro-sample is suppressed in a device in which a substrate is made of silicon, so that reliability of failure analysis is improved. 
   (9) The system for failure analysis with the configuration is characterized in that the apparatus for processing has an ion beam marking function for marking the sample to make extraction coordinates obvious before extraction of the sample. 
   With the configuration, coordinates corresponding to the original substrate of a micro-sample after extraction can be easily identified. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagram for explaining a general configuration of a system for failure analysis according to the invention. 
       FIGS. 2(   a ) to  2 ( g ) are diagrams for explaining a conventional sample separating method (prior art 1). 
       FIGS. 3(   a ) and  3 ( b ) are diagrams for explaining conventional sample separating methods (prior arts 2 and 3). 
       FIG. 4  is a diagram for explaining a conventional method of extracting a micro-sample every process (prior art 4). 
       FIGS. 5(   a ) to  5 ( d ) are diagrams for explaining an influence on an observation section structure by a later process. 
       FIG. 6  is a diagram for explaining a process of extracting and selecting a micro-sample in a device process flow. 
       FIG. 7  is a diagram for explaining an example of the configuration of an apparatus for micro-sample extraction. 
       FIGS. 8(   a ) to  8 ( i ) are diagrams for explaining an example of a micro-sample extraction flow. 
       FIGS. 9(   a ) to  9 ( c ) are diagrams for explaining an example of a method of filling a processed hole. 
       FIG. 10  is a diagram for explaining another example of the configuration of an apparatus for micro-sample storage. 
       FIGS. 11(   a ) to  11 ( e ) are diagrams for explaining an example of extraction of a micro-sample from a micro-sample storage and an additional process. 
       FIGS. 12(   a ) to  12 ( d ) are diagrams for explaining an example of a size necessary for a micro-sample with respect to a device repetition pattern. 
       FIGS. 13(   a ) to  13 ( d ) are diagrams for explaining an example of the extraction position of a micro-sample in a wafer. 
       FIGS. 14(   a ) to  14 ( d ) are diagrams for explaining an example of marking for coordinate identification. 
       FIG. 15  is a diagram for explaining the configuration of an apparatus for micro-sample extraction by a tilted ion beam optical system. 
       FIGS. 16(   a ) to  16 ( c ) are diagrams for explaining an example of the shape of a micro-sample storage. 
       FIGS. 17(   a ) to  17 ( c ) are diagrams for explaining an example of the shape of a storage hole of the micro-sample storage. 
       FIG. 18  is a diagram for explaining an example of managing a micro-sample storage together with a wafer cassette. 
       FIGS. 19(   a ) to  19 ( c ) are diagrams for explaining an example of a wafer-shaped micro-sample storage. 
       FIG. 20  is a diagram for explaining an example of marking management numbers of the micro-sample storages. 
       FIGS. 21(   a ) to  21 ( c ) are diagrams for explaining an example of information management of the micro-sample storage by a process tag. 
       FIGS. 22(   a ) to  22 ( c ) are diagrams for explaining an example of information management of the micro-sample storage by a memory card. 
       FIGS. 23(   a ) to  23 ( c ) are diagrams for explaining an example of information management of the micro-sample storage by a non-contact IC chip. 
       FIG. 24  is a diagram for explaining an example of management of an individual micro-sample by a non-contact IC chip. 
       FIGS. 25(   a ) and  25 ( b ) are diagrams for explaining an example of carriage of the micro-sample by a tweezers-type probe. 
       FIG. 26  is a diagram for explaining an example of the configuration of a system for failure analysis applied to product history investigation. 
       FIG. 27  is a diagram for explaining an example of the configuration of the system for failure analysis applied to generation of a process control support data base. 
       FIG. 28  is a diagram for explaining an example of the configuration of the system for failure analysis in the case of monitoring the details of a cause of a failure by paying attention to an abnormal portion. 
       FIGS. 29(   a ) to  29 ( c ) are diagrams for explaining selection of a micro-sample extraction position in the case of extracting a micro-sample by paying attention to an abnormal portion. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described in detail hereinbelow with reference to the drawings. 
     FIG. 1  shows the configuration of an example of a system for failure analysis according to the invention. A system  101  for failure analysis is constructed by: an apparatus  102  for micro-sample extraction capable of directly extracting a micro-sample having a size of about a few microns to tens microns without cutting a wafer; an apparatus  103  for micro-sample storage for storing the extracted micro-sample; an apparatus  104  for filing data of the stored sample for controlling management data of the micro-sample; an apparatus  105  for additional processing the micro-sample, which processes the stored micro-sample into a form for analysis in response to a failure analysis request; and an apparatus  106  for failure analysis for analyzing the processed micro-sample. 
   The outline of the system for failure analysis will be described hereinbelow. First, a process which is expected to be subjected to failure analysis later is selected from device manufacturing processes. 
     601  to  607  shown in  FIG. 6  indicate processes of device manufacture and correspond to, for example, exposure, dry etching, CVD (Chemical Vapor Deposition), wet etching, CMP (Chemical Mechanical Polish), and the like. For example, if the processes  602  and  605  are selected as processes of extracting a micro-sample from the processes  601  to  607 , the processes are preliminarily input as information  119  of an extraction schedule and an extraction position to the apparatus  104  for filing data of the stored sample. 
   When it is assumed in  FIG. 1  that an apparatus for performing the process  602  is an apparatus  107  for processing, according to the information, a wafer  108  processed by the apparatus  107  for processing is introduced into the apparatus  102  for micro-sample extraction in the system  101  for failure analysis. The apparatus  104  for filing data of the stored sample receives process information  114  from the apparatus  107  for processing (or a data base for managing process parameters of the apparatus  107  for processing) and transmits information  115  of a position from which the micro-sample is extracted in the wafer, a position of a micro-sample storage for storing the micro sample, and the like to the apparatus  102  for micro-sample extraction, and the like. On the basis of the extraction position information and the storage position information, the apparatus  102  for micro-sample extraction extracts a micro-sample  110  from the wafer  108  and stores the micro-sample  110  into a designated position in a micro-sample storage  109 . The apparatus  103  for micro-sample storage is connected to the apparatus  102  for micro-sample extraction, and the micro-sample storage  109  is stored in the apparatus  103  for micro-sample storage. Information  116  of a storage position in the apparatus  103  for micro-sample storage is sent to the apparatus  104  for filing data of stored sample. 
   The micro-sample is managed as data by the apparatus  104  for filing data of the stored sample and stored as hardware in the apparatus  103  for micro-sample storage. The wafer  108  from which the micro-sample  110  is extracted is subjected to the following process  603  as shown in  FIG. 6 . After that, the wafer subjected to the process  605  is introduced into the apparatus  102  for micro-sample extraction in the system  101  for failure analysis and a micro sample is extracted. In such a manner, the micro sample is similarly stored into the apparatus  103  for micro-sample storage in important points in the process. 
   Examples of information recorded in the apparatus  104  for filing data of the stored sample at the time of micro-sample extraction (at the time point when the micro-sample is housed in the micro-sample storage) are a process flow, process parameters (such as temperature and time), process date and time, wafer lot number, micro-sample extraction process, micro-sample extraction lot, micro-sample extraction wafer, micro-sample extraction chip, micro-sample extraction bit address, micro-sample extraction direction, micro-sample storage number, and micro-sample storage hole number. 
   After that, for example, after an inspection process, when a process to be subjected to failure analysis and the details of the failure analysis are determined, a failure analysis requirement  120  is input to the apparatus  104  for filing data of the stored sample. The apparatus  104  for filing data of the stored sample retrieves the storage position of the micro-sample  110  from a data base. The apparatus  103  for micro-sample storage receives the storage position information and introduces the corresponding micro-sample storage  109  to the connected apparatus  105  for additional processing the micro-sample. The apparatus  105  for additional processing the micro-sample receives the information  117  of the storage position of the micro-sample  110  in the micro-sample storage  109  and an additional process position from the apparatus  104  for filing data of the stored sample, extracts the corresponding micro-sample  110 , places the extracted micro-sample  110  onto a sample holder, and performs an additional processing such as a thinning process (for example, forming a gate vertical section). A specimen  113  for failure analysis subjected to the additional process as described above is introduced into the apparatus  106  for failure analysis where failure analysis is conducted. Analysis information  118  is transmitted to the apparatus  104  for filing data of the stored-sample and stored. Information obtained by adding the analysis information  118  with process information and the like is output as failure analysis information  121 . In such a manner, failure analysis data (including image data) is output in response to the failure analysis request. 
   By constructing such a system, a micro-sample extracted immediately after an arbitrary process can be stored. Thus, a failure can be directly analyzed in response to a request for analyzing a failure which is found later. Thus, efficient analysis can be realized. 
   A concrete configuration of the apparatus for micro-sample extraction as a key apparatus among the apparatuses constructing the system for failure analysis of the invention will now be described with reference to  FIG. 7 . 
   The apparatus  102  for micro-sample extraction includes: a movable specimen stage  702  on which a specimen substrate such as the semiconductor wafer  108  is placed; a specimen-stage position controller  703  for controlling the position of the specimen stage  702  for specifying the observation/process position of the wafer  108 ; an ion-beam irradiating optical system  705  for irradiating the wafer  108  with an ion beam  704  to perform a process; an electron-beam irradiating optical system  707  for emitting an electron beam  706  for observing the periphery of the wafer  108 ; and a secondary-electron detector  708  for detecting secondary electrons from the wafer  108 . 
   The configuration of the ion-beam irradiating optical system  705  is as follows. An acceleration voltage with respect to a ground voltage is applied from a power source  716  for an acceleration voltage to an ion source  715  for generating ions. In the case where ion discharge of the ion source  715  is unstable, Joule&#39;s heating is performed from a power source  717  for Joule&#39;s heating, thereby improving the state of the ion source  715 . An extractor  718  for generating an ion extracting electric field applies an extraction voltage from an extractor power source  719  to the ion source  715 . Spread of an ion beam extracted is regulated by an aperture  720 . The aperture has the same potential as that of the extractor  718 . The ion beam passed through the aperture  720  is condensed by a condenser lens  722  to which a condense voltage is applied from a condenser-lens power source  721 . The condensed ion beam is scanned and deflected by a deflector  724  to which a power from a deflector power source  723  is applied. The deflected ion beam is condensed onto the surface of the wafer  108  by an objective lens  726  to which an objective voltage is applied from an objective-lens power source  725 . The power source  716  for acceleration voltage, extractor power source  719 , condenser-lens power source  721 , deflector power source  723 , and objective-lens power source  725  are controlled by a controller  727  for ion-beam irradiating optical system. 
   A probe  728  for extracting a micro-sample in the wafer  108  processed with the ion beam  704  is driven by a probe driver  729  controlled by a probe position controller  730 . The position, heater temperature, valve opening/closing, and the like of a deposition-gas supplying source  731  for supplying a deposition gas for forming an ion beam assisted deposition film used for fixing the probe  728  and the micro-sample are controlled by a deposition-gas controller  732 . The micro-sample storage  109  having a plurality of holes for storing extracted micro-samples is disposed on a side of the specimen stage  702 . 
   Electron beam irradiation conditions, position, and the like of the electron-beam irradiating optical system  707  are controlled by a controller  733  for electron-beam irradiating optical system. The controller  727  for ion-beam irradiating optical system, specimen-stage position controller  703 , probe position controller  730 , a monitor  734  for displaying detection information of the secondary-electron detector  708 , and the like are controlled by a central processing unit  735 . The specimen stage  702 , micro-sample storage  109 , ion-beam irradiating optical system  705 , electron-beam irradiating optical system  707 , secondary-electron detector  708 , probe  728 , and the like are disposed in a vacuum chamber  737 . The central processing unit  735  transmits/receives micro-sample extraction position information and storage position information to/from the apparatus  104  for filing data of stored-sample. 
   A concrete method of storing a micro-sample into the micro-sample storage  109  will be described with reference to  FIGS. 8(   a ) to  8 ( i ) from a state where the wafer  108  is introduced into the apparatus  102  for micro-sample extraction shown in  FIG. 7  after completion of a device process. 
   First, rectangular holes  801  and  802  are formed with the ion beam  704  on both outer sides of a portion from which a micro-sample is to be extracted in the wafer  108  ( FIG. 8(   a )). After that, a rectangular trench  806  is formed with the ion beam  704  ( FIG. 8(   b )). The specimen stage  702  is tilted so that the specimen surface is irradiated obliquely with the ion beam  704  to form an inclined trench  808 , thereby forming the micro-specimen  110  connected with the wafer  108  only via a residual area  805  ( FIG. 8(   c )). The tilted specimen stage is set to the original state, and the probe driver  729  is controlled by the probe position controller  730  so that the probe  728  comes into contact with a part of the micro-sample  110 . The probe  728  and the micro-sample  110  which are in contact with each other are fixed by using ion beam assisted deposition ( FIG. 8(   d )). After an ion beam assisted deposition film  809  is formed, the residual area  805  is cut with the ion beam  704  ( FIG. 8(   e )). 
   The micro-sample  110  is cut out in such a manner and extracted by lifting the probe  728  by the probe driver  729  ( FIG. 8 ) f )). After that, the micro-sample  110  which is cut out is inserted into a storage hole  811  in the micro-sample storage  109  ( FIG. 8(   g )). After the insertion, the tip of the probe  728  is cut with the ion beam  704  to separate the micro-sample  110  ( FIG. 8(   h )). In such a manner, the micro-sample  110  is stored into the micro-sample storage  109  ( FIG. 8(   i )). In the case of extracting micro-samples in a plurality of positions after that, the process is repeated, the micro-sample  110  is stored into another storage hole  812 . 
   The micro-sample extraction has been described with respect to the case of using the apparatus for micro-sample extraction as shown in  FIG. 7  in which the specimen stage  702  is tilted. However, in an apparatus configuration in which a specimen stage  1501  is not tilted but an ion-beam irradiating optical system  1502  is disposed so as to be tilted with respect to the specimen surface as shown in  FIG. 15 , by rotation control using the normal line to the specimen surface of the specimen stage  1501  as a rotation axis, a micro-sample extracting process as described above can be realized. 
   The mechanism of  FIG. 15  is similar to that of  FIG. 1  except for the above-described tilt configuration. In  FIG. 15 , for simplicity of the diagram, a probe related mechanism and a deposition gas source related mechanism are not shown but exist in reality. 
   The wafer  108  is taken out from the apparatus  102  for micro-sample extraction and is subjected to the next device process (process  603  in the case of  FIG. 6 ). In the wafer  108 , a processed hole for micro-sample is open. Consequently, there is the possibility that the processed hole causes a failure in any of the subsequent processes. It is therefore desired to fill the processed hole.  FIGS. 9(   a ) to  9 ( c ) show an example of a filling method. 
     FIG. 9(   a ) shows a state where the micro-sample  110  is extracted from the wafer  108  by the probe  728  and a processed hole  901  is open. By scanning the processed hole  901  with the ion beam  704  while supplying a deposition-gas  902  (such as phenanthrene, tungsten hexacarbonyl, or tetraethoxysilane) from the deposition-gas supplying source  731 , the hole can be filled with a deposition material  903  as shown in FIG.  9 ( c ). By making the wafer  108  in which the hole is filled subject to the next process, a process failure caused by the processed hole can be suppressed. 
   On the other hand, the micro-sample storage  109  for storing the extracted micro-sample  110  is stored in the apparatus  103  for micro-sample storage capable of storing a plurality of micro-sample storages. The apparatus  103  for micro-sample storage has a configuration, for example, as shown in  FIG. 10 , including a load/unload system  1001  capable of loading/unloading an arbitrary micro-sample storage  109  and can be connected to the apparatus  102  for micro-sample extraction or the apparatus  105  for additional processing micro-sample via a connecting apparatus section  1002 . The micro-sample storage  109  can be loaded or unloaded without being exposed to the atmosphere. 
   An area to be observed and analyzed in a test or the like in a post process on the wafer  108 , in the micro-sample stored as described above is determined. For example, in a probe test, failure information of short-circuit, breaking of wire, writing, reading, and the like is obtained. On the basis of the failure information, a process, an area, a direction, and the like to be actually observed are determined. For example, in the case where breaking of metal wires often occurs, observation of sections of a few processes after a metal line forming process is determined. In the case where, for example, a plug, a contact, or the like has high resistance, a section of a residual film of an etched hole for a plug, a section of a plug, a plan view of the connecting portion, or the like is determined. 
   Based on the information determined as described above, corresponding wafer lot, wafer, process, and chip are determined, the micro-sample storage  109  is introduced into the apparatus  105  for additional processing micro-sample, and a micro-sample (in this case, the micro-sample  110 ) is extracted from a corresponding storage hole. The extraction will be described by referring to  FIGS. 11(   a ) to  11 ( e ). 
   As shown in  FIG. 11(   a ), the micro-sample  110  is extracted by using a probe  1105 . Although it is drawn that the storage hole  811  and the like are open to this side, the holes are individual holes which are not open to the side face in reality. The micro-sample  110  may be extracted by the above-described method using the ion beam assisted deposition film or a method using tweezers which will be described later. 
   In the case where the area to be observed and analyzed (hereinbelow, described as “area to be observed” in order to simplify the description) determined from the test result is, for example, a section perpendicular to the specimen surface of the original wafer  108 , the micro-sample  110  is fixed in a posture such that the observation section is parallel to the longish direction  1103  of a surface  1102  for fixing the micro-sample of a micro-sample holder  1101  for introducing the micro-sample into an observation apparatus and is perpendicular to the surface  1102  for fixing the micro-sample. The fixing is carried out by, for example, an ion beam assisted deposition film  1104  or the like. After that, the probe  1105  is removed (for example, in the case where the ion beam assisted deposition is used for fixing the probe  1105 , the tip of the probe  1105  is cut with the ion beam  1106 ) and a cross section of the target area is obtained or the target area is thinned to a thickness of about 100 nm, thereby enabling a section to be observed in a desired position by an SEM or TEM as shown in  FIG. 11(   c ). 
   In the case where the observation area determined from the result of the test is a surface parallel to the specimen surface of the original wafer  108 , the micro-sample is fixed in a posture such that the observation surface is parallel to the longish direction  1103  of the surface  1102  for fixing the micro-sample of the micro-sample holder  1101  and is perpendicular to the surface  1102  for fixing the micro-sample as shown in  FIG. 11(   d ). The fixing as shown in  FIG. 11(   d ) can be realized when the probe  1105  has a rotating mechanism and the posture of the micro-sample  110  can be turned by 90° from the posture at the time of extraction. If the probe  1105  does not have the rotating mechanism, as shown in  FIG. 11(   d ′), the micro-sample holder  1101  is tilted by 90° in advance and the micro-sample  110  is fixed to the tilted micro-sample holder  1101 . After that, the probe  1105  is removed in a manner similar to the case of the perpendicular cross section and, in the case of  FIG. 11(   d ′), the posture is returned by 90°. By forming a section of the target plane position or thinning the target plane area, as shown in  FIG. 11(   e ), the plane in the desired position can be observed. 
   Although the case where the apparatus  102  for micro-sample extraction and the apparatus  105  for additional processing micro-sample are separate apparatuses has been described, a single apparatus can be used for extracting the micro-sample and performing an additional process. 
   The size of the micro-sample  110  to be extracted will now be described. An object of the invention is to provide an arbitrary observation surface which is determined after a device inspection, so that it is necessary to assure a minimum repetition pattern of the device. Although a repetition pattern of a large cycle exists naturally, an object is a repetition pattern of a size of about 100 μm or less which does not exert an influence on the process and can be processed in realistic time with an ion beam. 
   For example, if device patterns  1201 ,  1202 ,  1203 , and  1204  as shown in  FIG. 12(   a ) are repetition patterns, the micro-sample  110  of a size including at least one ( 1201 ) of the patterns is extracted. The repetition patterns include one pattern with respect to naturally the specimen surface and also with respect to the inside of the specimen (depth direction). 
   In  FIG. 12(   a ), the case of a simple configuration in which one pattern of a DRAM or the like has one transistor and one capacitor is shown. For example, in the case of an SRAM (Static Random Access Memory), in some cases, six transistors exist in one pattern. In such a case, the size including all of the six transistors has to be extracted. 
     FIG. 12(   b ) shows an example of the surface after a wiring process of an SRAM. A repetition pattern corresponding to storage of one bit is as shown in  FIG. 12(   c ) (in  FIG. 12(   b ), the boundary is indicated by broken lines). Consequently, in an ion beam process for extracting the pattern, an area indicated by  1205  in  FIG. 12(   d ) has to be extracted. By assuring the size of the micro-sample to be extracted as described above, an arbitrary position in a pattern can be additionally processed. 
   Coordinates at the time of extracting a micro-sample in the wafer  108  will now be described. The object to be analyzed by the system is a failure caused by a problem of a process itself rather than a failure existing in a specific point. Since failures of a process itself often vary according to positions such as the center of the wafer and a periphery, it is desirable to store nine points such as  1302  and  1303  shown in  FIG. 13(   a ) in the surface of the wafer  108  per process. 
   Consequently, in the following micro-sample extracting process as well, micro-samples are similarly extracted from nine points. However, the positions of points  1304 ,  1305 , . . . shown in  FIG. 13(   b ) different from the extraction positions ( 1302 ,  1303 , . . . ) of last time are selected. Micro-samples are similarly extracted while changing the extraction positions.  FIG. 13(   c ) shows, for example, points ( 1306 ,  1307 ,  1308 ,  1309 , . . . ) to be analyzed after four kinds of processes. Although the position to be analyzed is largely drawn as compared with the wafer size for easier understanding, the areas to be analyzed in reality are sufficiently small. Consequently, as shown in  FIG. 13(   d ) for example, all of points to be analyzed are within one chip  1310 . The number of chips sacrificed for failure analysis is sufficiently small, so that it is efficient. However, since a failure may occur due to the influence of deterioration of the area of the extracting process near the extracted portion (including the process of filling the processed hole), it is necessary to set analysis points of processes so as not to be too close to each other. 
   Once a micro-sample is extracted from a wafer, it becomes difficult to make the coordinates in the wafer and those of the micro-sample coincide with each other. In order to make the coordinates coincide with each other, marking as described below is effective. 
   In a coordinate system in the wafer  108 , as shown in  FIG. 14(   a ), a notch  1402  is positioned at the bottom and an intersecting point of peripheral tangents is set as the origin  1403 . The coordinates of an analysis point  1401  are expressed by an abscissa  1404  and an ordinate  1405 . Although the analysis point  1401  is indicated by X in the diagram, such a mark does not exist in reality. In order to identify the analysis point  1401 , as shown in  FIG. 14(   b ), marks  1407  and  1408  are formed by an ion beam process. 
   A rectangular frame on the inside indicates an area  1409  of a micro-sample to be extracted, and an area surrounded by two quadrangles is an area  1406  to be processed with an ion beam. Consequently, the marks  1407  and  1408  are formed so as to extend at least into the area  1409 . From the viewpoint of forming the mark of the extraction position also in the wafer  108 , it is desirable to form the marks  1407  and  1408  so as to extend to the outside of the area  1406  for processing.  FIG. 14(   c ) shows a state after the ion beam processing for extraction. Even after an ion-beam processed area  1410  is cut and the micro-sample is extracted as shown in  FIG. 14(   d ), the analysis point  1401  can be identified from the positions of the marks  1408  and  1407 . 
   As described above, a sample at the time of a process finished before can be assured by the failure analysis system for extracting and storing a micro-sample every arbitrary process of the invention. Thus, an observation image of the target position which is not influenced by subsequent processes can be obtained, and a failure analysis system capable of efficiently finding out the cause of a failure can be realized. 
   An example of the shape of the sample storage in the invention will now be described by referring to  FIGS. 16(   a ) to  16 ( c ). 
     FIG. 16(   a ) shows an example of the micro-sample storage  109  slidably attached/detached to/from the specimen stage  102  on which the wafer  108  is placed.  FIG. 16(   b ) is an enlarged diagram of the micro-sample storage  109  having a plurality of storage holes  811 ,  812 , . . . . Although the storage hole  811  is shown very large for easier understanding of the drawing, in practice, the size of the storage hole  811  is about tens μm in relation to the size of the micro-sample holder  109  ranging from a few mm to a few cm. The micro-sample storage  109  is attached to the specimen stage  102  so as to be slid along a trench  1602 . The shape of only the micro-sample storage is shown in  FIG. 16(   c ). The micro-sample storage can be detached simultaneously with or subsequent to extraction of the wafer  108 . For the following another wafer, a new micro-sample storage is introduced. 
   Further, the shape of the storage hole is, ideally, the shape adapted to a wedge shape of the extracted micro-sample shown as the storage hole  811  in  FIG. 11 . However, the possibility that such a shape can be obtained by a process with an ion beam, a laser beam, or the like is high, so that such a shape is not efficient when a large volume of holes are opened. Consequently, a shape which can be formed by using photolithography, etching, and the like is desirable. 
     FIG. 17(   a ) to  17 ( c ) show examples of the sectional shape of the storage hole.  FIG. 17(   a ) shows an example of a storage hole  1701  having a rectangular shape. In this case, considering that the micro-sample  110  is taken again, the storage hole  1701  is formed so that its depth is slightly smaller than that of the micro-sample  110 . With the configuration, the posture of the micro-sample  110  can be kept.  FIG. 17(   b ) shows a storage hole  1702  having a parallelogram shape in which, not the face perpendicular to the micro-sample, but a tilted face of a larger area is used as a contact face, thereby enabling stabler storage. In this case as well, the depth of the storage hole  1702  is set to be smaller than that of the micro-sample  110 , thereby enabling the posture of the micro-sample  110  to be maintained. The top face of the micro-sample  110  is projected from the surface of the micro-sample storage  109 . If it is dangerous, it is desirable that a guard  1703  exists so as to protect the projected portion of the micro-sample  110  as shown in  FIG. 17(   c ). In such a manner, a safe micro-sample storage can be easily formed. 
   As a material of the micro-sample storage, a material which does not contaminate the micro-sample is desirable. For example, when the sample substrate is a silicon wafer, by making the micro-sample storage of silicon as well, contamination can be suppressed. Since silicon is also adapted to microfabrication by photolithography and etching, it is optimum to form the storage hole as well. 
   Since it is efficient to manage a wafer (or a lot) by the same micro-sample storage, preferably, the micro-sample storage  109  (micro-sample  110 ) is managed together with the original wafer which is moved among the process apparatuses. A form of managing the micro-sample storage  109  together with a wafer case (cassette) will be described by referring to  FIG. 18 . 
   A wafer cassette  1802  is used to store and move wafers  1801  to be processed in the same lot. On a side face of the wafer cassette  1802 , a storage set space  1803  in which the micro-sample storage  109  can be mounted is provided. With such a configuration, a wafer process and a micro-sample can be easily associated with each other. 
   As another method of managing the micro-sample  110  (micro-sample storage) together with the original wafer, a wafer-shaped sample storage shown in  FIGS. 19(   a ) to  19 ( c ) will be described. 
     FIG. 19(   a ) shows a state where the micro-sample  110  is extracted from the wafer  108  by the probe  728 . In the wafer  108 , a processed hole  1902  from which the micro-sample is extracted exists. The wafer  108  is returned to the wafer cassette  1802  in which one of wafers is not actually a wafer but a micro-sample storage  1901  having the same shape as the wafer. After the wafer  108  is returned, the micro-sample storage  1901  is introduced onto the specimen stage  702 . 
   In the micro-sample storage  1901 , storage holes  1903  of micro-samples and the like are formed. Although the storage holes  1903  each having a size larger than the actual size are drawn like the case of  FIG. 16 , in reality, the size is tens μm in relation to the wafer size of, for example, 200 mm or 300 mm. As shown in  FIG. 19(   b ), the micro-sample  110  is stored into the storage hole  1903 . After that, the micro-sample storage  1901  is returned to a predetermined position in the wafer cassette  1802  as shown in  FIG. 19(   c ). As a matter of course, in the case of setting the wafers  108  into the apparatus for processing, the micro-sample storage  1901  is controlled so as not to be erroneously introduced into the apparatus for processing. 
   In the case of extracting a micro-sample from a few places after a process from a single wafer, the wafer-shaped micro-sample storage is disadvantageous from the viewpoint of time since a wafer is loaded and unloaded for each extraction. However, in the case of extracting a micro-sample from only one position, it is effective with respect to the point that the wafer-shaped micro-sample storage can be easily managed together with wafers. 
   As described above, productivity of the micro-sample storage is improved by selecting the shape of a hole. By employing the form that the micro-sample storage can be carried together with the wafer, management is facilitated. 
   The process in the system for failure analysis according to the invention and a method of managing the micro-sample data will now be described. 
   As described also in the foregoing embodiment, the micro-sample storages  109  are numbered in order to identify micro-samples. For example, the surface of the micro-sample storage  109  may be marked with a corresponding wafer lot number  2001  such as “Lot#0123” or another unique number. If each storage hole, for example, the storage hole  811  is marked with “01” or the like as a micro-sample storage hole number  2002 , management is easy. 
   Another data management method of the micro-sample holder  109  is as shown in  FIGS. 21(   a ) to  21 ( c ).  FIG. 21(   a ) shows a form of employing a process tag holder  2102  for attaching a process tag  2101  describing process information, the place where a micro-sample is to be extracted, and the like to the micro-sample holder  109  itself. By the form, a process operator can know at a glance a process after which a micro-sample is to be extracted. 
   In the form where a process tag holder  2103  is attached not directly to the micro-sample holder  109  but to the storage set space  1803  as shown in  FIG. 21(   b ), the area is not directly in the vacuum so that it is safe from the viewpoint of contamination. In the case where the micro-sample storage can be managed together with the wafer cassette, as shown in  FIG. 21(   c ), the process tag  2101  may be fixed to the wafer cassette  1802  by a process tag holder  2104 . 
   It is also possible to employ a form of writing information corresponding to a process tag into a memory card such as a flash memory in place of a process tag and providing memory card holders  2202 ,  2203 , and  2204  for holding memory cards  2201  shown in  FIGS. 22(   a ),  22 ( b ), and  22 ( c ) corresponding to the forms of  FIGS. 21(   a ),  21 ( b ), and  21 ( c ), respectively. In this case, a terminal such as a reader/writer capable of reading and writing process information or the like of the memory card  2201  is prepared in a place accessed by the process operator. 
   Similarly, there are also methods of using non-contact IC chips  2301  of  FIGS. 23(   a ),  23 ( b ), and  23 ( c ) corresponding to the forms of  FIGS. 21(   a ),  21 ( b ), and  21 ( c ), respectively. A non-contact IC chip is a chip which has a size of about 0.4 mm and in which an RF analog circuit and a memory are integrated. In the non-contact IC chip, a single (unique) numerical value is recorded. A data base in which the numerical value and micro-sample information (process flow, process parameters (temperature, time, and the like), process date and time, wafer lot number, micro-sample extracting process, micro sample extraction lot, micro-sample extraction wafer, micro-sample extraction chip, micro-sample extraction bit address, micro-sample extraction direction, micro-sample storage number, micro-sample storage hole number, and the like) are associated with the apparatus  104  for filing data of stored-sample is configured. In such a manner, only by reading the numerical value written in the non-contact IC chip, the information of the micro-sample can be promptly obtained. 
   Since the non-contact IC chip is small and cheap, the invention is not limited to the form of providing one non-contact IC chip for one micro-sample storage  2403 , but it is also possible to employ a form of providing a micro-sample storage part (for example,  2401 ) for each micro-sample (for example,  110 ) and a non-contact IC chip (for example,  2402 ) is attached to each micro-sample storage part. In this case, a micro-sample and stored data correspond to each other in a one-to-one manner as hardware and data, so that management becomes reliable. 
   As described above, the wafer process information and the micro-sample extraction information are managed, an observation position by inspection information is determined, and a sample to be observed is prepared, thereby increasing reliability of management of failure analysis data and facilitating clarification of the cause of a failure. 
   An efficient shape of a probe for carrying a micro-sample in the system for failure analysis according to the invention will now be described. 
   Although the case of using ion beam assisted deposition for fixing the probe and the micro-sample has been described above, in this case, the probe is damaged by ion beam sputtering at the time of separation. On the other hand, there is a tweezers-type probe  2501  shown in  FIGS. 25(   a ) and  25 ( b ) in a nondestructive, more-efficient probe form. The tip of the probe is forked and a micro-sample is sandwiched by utilizing the elastic deformation the probe. 
   The micro-sample  110  extracted as shown in  FIG. 25(   a ) is carried to the micro-sample storage  109  shown in  FIG. 25(   b ) and inserted into the storage hole  811 . The tweezers-type probe  2501  is pulled out in the direction of the arrow  2502  to be thereby separated, and the micro-sample  110  remains in the storage hole  811 . At the time of taking the micro-sample  110  again, the micro-sample  110  is held again by the elastic deformation of the tip of the tweezers-type probe  2501  and carried to the micro-sample holder. 
   By using the tweezers-type probe as described above, the micro-sample can be stored and taken out again efficiently without destroying the probe. 
   The procedure of applying the system for failure analysis according to the invention to a product history investigation will be described hereinbelow. 
     FIG. 26  shows the configuration of the system for failure analysis and the flow of information. Although the configuration is the same as that of  FIG. 1 , in the case of the example, a failure found after shipment of a product is a target. Therefore, all of micro-samples extracted from the original wafer of a chip already shipped as a product are stored in the apparatus  103  for micro-sample storage. In the case where a failure is found after shipment of a product device, when information  2602  of product failure is input to a product data base  2061 , a corresponding product and wafer name and, further, a process and an observation position having high possibility as the cause of the failure (for example, a gate perpendicular section after a wiring process) are determined, and this selection information  2603  is input to the apparatus  104  for filing data of stored-sample. The apparatus  104  for filing data of stored-sample detects the storage position of a corresponding micro-sample from the micro-sample data base. 
   In such a manner, failure analysis is conducted in a manner similar to the embodiment of the invention and the cause of a failure is specified. Analysis information  2604  (including an image and the like) is also transmitted to the apparatus  104  for filing data of stored-sample and stored. The analysis information  2604  is transmitted to the product data base  2601  and managed together with the initial information  2602  of product failure. The cause of the failure specified as described above is used for explanation to the customer of the product. 
   As described above, the cause of a failure in a corresponding process can be clarified even after shipment of the product by the system for failure analysis, and it is effective to explain the situation to the customer. 
   The procedure of applying the system for failure analysis according to the invention to acquisition of support data of an advanced process control will now be described. 
   The advanced process control (APC) is a method of setting multivariable process parameters to thereby manage a change in the yield and predicting a process parameter by which the yield is improved, thereby optimizing the parameter. In this case, depending on the setting of the parameters, there is the possibility that the parameters are largely deviated from the optimum parameters and an effective advanced process control is not achieved. In order to limit the direction and the range of setting the process parameters, support data is obtained as described below by the system for failure analysis. 
     FIG. 27  shows the configuration of the system for failure analysis and the flow of information. The flow up to the storage of the micro-sample is similar to that in the foregoing embodiment. After that, the wafer is inspected by an inspection apparatus  2701 . By using a preset threshold, a wafer and a process which are determined as defective and, further, an observation position in which the possibility that a failure is observed is high are determined. This selection information  2703  is input to the apparatus  104  for filing data of stored-sample. The apparatus  104  for filing data of stored-sample identifies the storage position of a corresponding micro-sample from the data base. 
   The failure analysis is conducted in a manner similar to the foregoing embodiments and the cause of a failure is specified. The analysis information (including an image) is also transmitted to the apparatus  104  for filing data of stored-sample and stored. This analysis information  2704  is transmitted together with the process information  114  and inspection information  2705  of a failure sample to a failure data base  2702  and stored. From the failure data base  2702 , a process parameter in which a failure easily occurs is specified easily. 
   As described above, by the system for failure analysis, a process parameter in which a failure easily occurs is easily specified, so that the direction of setting a parameter in the advanced process control can be limited and the efficiency is accordingly increased. 
   An example of the system for failure analysis for monitoring the details that, in a position determined as an abnormal part by an initial wafer inspection, a failure occurs in a later process. 
     FIG. 28  shows the configuration of the system for failure analysis and the flow of information. In the foregoing embodiment, as the extraction position of a micro-sample, a proper position is preset as described above. In the case of the example, the extraction position is determined from an inspection result of an inspection apparatus  2805 . 
   The determination of the position will be described by referring to  FIGS. 29(   a ) to  29 ( c ). For example,  FIG. 29(   a ) shows a result of a foreign matter inspection of a wafer. The x marks of points  2901 ,  2902 , . . . indicate positions where foreign matters are observed. Foreign matters are particularly narrowed to those which are considered to be similar from the viewpoints of size and the like. The information  119  of the positions as positions in which micro-samples are extracted after the subsequent selecting process is input to the apparatus  104  for filing data of stored-sample. According to the information, for example, from a wafer subjected to a certain process, an area  2903  including the point  2901  is extracted as shown in  FIG. 29(   b ). From the wafer subjected to the following selecting process, an area  2904  including the point  2902  is extracted as shown in  FIG. 29(   c ). In such a manner, micro-samples are sequentially stored. After that, in response to a failure analysis requirement  2801 , selection information  2803  of a micro-sample is input to the apparatus  104  for filing data of stored-sample. The apparatus  104  for filing data of stored-sample identifies the storage position of a corresponding micro-sample from a data base. 
   Failure analysis is conducted in a manner similar to the foregoing embodiments and the cause of the failure is specified. The analysis information (including an image and the like) is also transmitted to the apparatus  104  for filing data of stored-sample and stored. Analysis information  2084  is transmitted to an apparatus  2802  for filing a data base of failures and stored. From the failure data base  2802 , information of a possible failure in a corresponding process, which is caused by an abnormal part detected in an initial inspection, can be obtained. 
   As described above, the cause of a failure when an initial abnormal part is noted can be specified by the system for failure analysis, so that process management parameters can be easily grasped. 
   As described specifically above, according to the invention, a sample at the time of a process which is finished before can be assured, so that an observation image in a target position which is not influenced by a later process can be obtained, and efficiency of finding out the cause of a failure can be increased. 
   According to the invention, a failure analysis technique capable of obtaining an observation sample corresponding to an arbitrary observation desired position determined by an inspection later in failure analysis of a device and the like can be realized.