Method and apparatus for processing a micro sample

An object of the invention is to realize a method and an apparatus for processing and observing a minute sample which can observe a section of a wafer in horizontal to vertical directions with high resolution, high accuracy and high throughput without splitting any wafer which is a sample. In an apparatus of the invention, there are included a focused ion beam optical system and an electron optical system in one vacuum container, and a minute sample containing a desired area of the sample is separated by forming processing with a charged particle beam, and there are included a manipulator for extracting the separated minute sample, and a manipulator controller for driving the manipulator independently of a wafer sample stage.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus system used as observation, analysis and evaluation means in research and development and manufacturing of an electronic device such as a semiconductor device, liquid crystal device and a magnetic head, a micro-electronic device or the like which require observation and analysis of not only a surface of an object to be observed but also an inner section near the surface.

In manufacturing of a semiconductor device such as a semiconductor memory typified by a dynamic random access memory, a microprocessor and a semiconductor laser, and electronic parts such as a magnetic head, a product property is inspected for quality control of a product during a manufacturing process or at completion of the process. In the inspection, measurement of manufacturing dimension, defect inspection of a circuit pattern, or analysis of foreign materials are carried out. For that purpose, various means are prepared and used.

Particularly, when there is a wrong portion within the product, a minute processing and observation apparatus is increasingly used which comprises a combination of a focused ion beam (FIB) apparatus and an electron microscope. This apparatus is disclosed in JP-A-11-260307 specification. In the specification, disclosed is a technique of carrying out section processing of a sample by an FIB apparatus and observing an exposed section by an electron microscope disposed slantingly above the sample.

As another technique of observing the sample section, invented and used is a method of taking out of a processing and observation apparatus a minute sample, which is a cut-out minute area of micron orders including an observation region, and moving the minute sample to a separately prepared apparatus to be reprocessed into an optimum shape and observed and analyzed. This method is disclosed in JP-A-5-52721 specification. This is a method of cutting out part of a sample and observing its section, where a tip of a probe driven by a manipulator is positioned on a minute sample cut by an FIB, the probe and minute sample are connected by a deposition gas, and the minute sample is transferred in the connected condition.

SUMMARY OF THE INVENTION

The above described conventional methods have the following problems.

First, to observe a section of a hole or groove of the sample formed by FIB processing, a sample stage is inclined to thereby observe a section of an inner wall of the hole or groove in a slanting direction. In that case, an adjustment range of inclination of the sample stage is limited by constraints in structure due to a working distance of an FIB apparatus, presence of an objective lens, or size of a sample stage, and larger inclination cannot be allowed. Thus, vertical observation of the section of the inner wall of the hole or groove is impossible. The vertical observation of the section is indispensable in confirmation of processing properties such as dry etching, planarization, thin film forming, or the like in process development or the like of semiconductor device manufacturing, but the above described known apparatuses cannot cope with the vertical observation.

Second, a reduction in resolution resulting from the slant observation becomes a serious problem. When slantingly emitting an electron beam to a wafer surface from above and to observe a section of an inner wall of a hole or groove, observation resolution in a direction perpendicular to the wafer surface, that is, of the section of the inner wall of the hole or groove is reduced. A reduction rate reaches approximately 15% at an angle of 30°, and 30% at an angle of around 45°, which is most frequently used. Miniaturization of recent semiconductor devices has reached the limit, and measurement of the dimension or shape with accuracy below a few nano meters is required. Required observation resolution is less than 3 nm, which falls a technical limit area of a scanning electron microscope. In addition, with high resolution of such degree, depth of focus is extremely shallow and focusing is achieved only in a range below some ten percent of 1 μm, so that an appropriate observation range of a vertical section of the device at the time of slant observation is often less than half of a required area. This problem can be solved by vertical observation. The vertical observation enables superior observation in focus on the whole observation area.

Third, the observation section exists on a wall surface of a minute hole or groove formed in the wafer, so that numeral density of secondary electrons coming out of the hole are reduced in comparison with those on the surface of the wafer. Thus, secondary electron detecting efficiency is reduced and it causes a reduction in S/N of a secondary electron image, inevitably resulting in a reduction in accuracy of the section observation.

Miniaturization of LSI patterns progresses at a rate of 30% reduction every a few years without stop, and higher resolution is increasingly required in the observation apparatus. Moreover, even if surface distribution of an atomic property X-ray excited by emitting an electron beam is measured by an X-ray detector to carry out elementary analysis (EDX analysis), enlargement of an X-ray generation area due to the electron beam entering into the sample causes surface resolution of analysis to be approximately 1 μm though the electron beam has a diameter equal or less than 0.1 μm, which is insufficient for analysis of the LSI element section having a minute structure.

Fourth, cases where the vertical observation of the section is indispensable include evaluation of workmanship of etching, implantation of grooves or holes, planarization or the like in wafer process. In order to accurately measure a dimension and shape of a processed section, a sample of a chip size including a section to be observed has been determined and observed by a scanning electron microscope for general purpose in the past. However, accompanying with miniaturization progress of devices and enlargement of diameter of the wafer, sometimes failure is resulted since it is considerably difficult to accurately break an element circuit pattern at a position to be observed. However, failure in creating an evaluation sample is not allowed because of poor supply capacity or increased price of the wafer for evaluation.

Fifth, with the technique disclosed in JP-A-5-52721 specification, it is possible to obtain sufficient level of observation and analysis accuracy such as resolution, but the sample has to be manufactured in the conventional apparatus, taken out of the apparatus, and introduced into the separately prepared observation and analysis apparatus, thus there is a problem of requiring hours of time for taking out the minute sample, processing, observation and analysis. Further, in a case where the sample exposed to the air is degraded by oxidation or moisture adsorption, it is difficult to avoid the degradation. Section observation of the semiconductor device has been recently considered to be important as an advantageous inspection technique in manufacturing the semiconductor, and a desirable throughput in that case at present is observation and analysis of more than a few positions per hour, and processing at much higher speed will be desired in the future. Contrary to the desire, the problem of extremely low throughput of the conventional method has not been solved.

In view of the above problems, the present invention has its object to provide a method and apparatus for processing and observing a minute sample, which can vertically observe an inner section of the sample to be observed, and can carry out observation and analysis with high resolution, high accuracy and high throughput without degradation resulting from exposure to the air and without failure.

Another object of the present invention is to provide a minute sample processing apparatus which requires minimum capacity of a vacuum container and a reduced occupying area and has high operability even when the apparatus is intended for a large sample. Still another object of the present invention will be described in embodiments described hereinafter.

In order to attain the above object, there is provided a minute sample processing apparatus, including: a focused ion beam optical system comprising an ion source, a lens for focusing an ion beam and an ion beam scanning deflector; an electron beam optical system comprising an electron source, a lens for focusing an electron beam and an electron beam scanning deflector; a detector for detecting a secondary particle emitted from the sample; and a sample stage on which the sample is placed, wherein the apparatus further comprises a probe for supporting a minute sample cut out by emitting the ion beam to the sample, and a mechanism for operating the probe.

Further, in order to attain another object, there is provided a charged particle beam apparatus, including: a sample stage for placing a sample in a vacuum container; a charged particle source; a irradiation optical system for irradiating a charged particle beam from the charged particle source to the sample; a secondary particle detector for detecting a secondary particle generated from the sample by applying the charged particle beam to the sample; a needle member whose tip is capable of coming into contact with the sample; a probe holder for holding the needle member; an introduction mechanism capable of introducing and extracting the probe holder into and from the vacuum container; and a moving mechanism having a mechanism of slanting the probe holder to a surface of the sample stage.

Structure and technical effects for achieving other objects of the present invention will be described in embodiments described hereinafter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A structure and an operation of a minute sample processing and observation apparatus according to the present invention will be described.

A structure and an operation of a first embodiment of an apparatus of the invention will be described with reference toFIGS. 1,2and3.FIGS. 1 and 2show a whole structure of the apparatus andFIG. 3shows structures of a focused ion beam optical system, scanning electron microscope optical system and around a sample stage in detail. Shown in this embodiment is a wafer corresponding apparatus in the minute sample processing and observation apparatus of the present invention.FIG. 3shows a schematic bird's eye section ofFIG. 1, and there are some differences between the figures, though not essential, in orientations or details of apparatuses for convenience in description. InFIG. 1, around a center of an apparatus system are appropriately located a focused ion beam optical system31and an electron beam optical system41above a vacuum sample chamber60. A sample stage24on which a wafer21to be a sample is placed is located inside the vacuum sample chamber60. Two optical systems31and41are adjusted in such a manner that their respective central axes intersect at a point on a surface or near the surface of the wafer21. A mechanism for moving the wafer21backward and forward, and right and left with high accuracy is provided in the sample stage24, and is controlled in such a manner that a designated position on the wafer21falls immediately below the focused ion beam optical system31. The sample stage24has functions of rotational, vertical and slanting movements. An exhaust apparatus (not shown) is connected to the vacuum sample chamber60and the chamber60is controlled so as to have an appropriate pressure. The optical systems31,41also individually comprise respective exhaust systems (not shown) and they are maintained at appropriate pressures. A wafer introducing device61and wafer conveying device62are provided within the vacuum sample chamber60. A wafer transferring robot82and a cassette introducing device81are disposed adjacent to the vacuum sample chamber60. Provided on the left side of the vacuum sample chamber60is an operation controller100for controlling the whole apparatus and a series of processing of sample processing, observation and evaluation.

Next, an outline of an operation of introducing the wafer in this embodiment will be described. When a wafer cassette23is placed on a table of the cassette introducing device81and an operation start command is issued from the operation controller100, the wafer transferring robot82pulls out a wafer to be a sample from a designated slot in the cassette, and an orientation adjustment device83shown inFIG. 2adjusts an orientation of the wafer21to a predetermined position. Then, the wafer transferring robot82places the wafer21on a placement stage63when a hatch on an upper portion of the wafer introducing device61is opened. When the hatch is closed, a narrow space is formed around the wafer to be a load lock chamber, and after air is exhausted by a vacuum exhaust device (not shown), the placement stage63is lowered. Next, the wafer conveying device62takes up the wafer21on the placement stage63and places it on the sample stage24at a center of the vacuum sample chamber60. The sample stage24is provided with means for chucking the wafer21according to need in order to correct a warp or prevent vibration of the wafer21. A coordinate value of an observation and analysis position on the wafer21is input from the operation controller100, and the sample stage24is moved and stopped when the observation and analysis position of the wafer21falls immediately below the focused ion beam optical system31.

Next, a process of sample processing, observation and evaluation will be described with reference to FIG.3. In the minute sample processing and observation apparatus of the present invention, the focused ion beam optical system31comprises an ion source1, a lens2for focusing an ion beam emitted from the ion source1, an ion beam scanning deflector3or the like, and the electron beam optical system41comprises an electron gun7, electron lens9for focusing an electron beam8emitted from the electron gun7, an electron beam scanning deflector10or the like. The apparatus is further provided with a secondary particle detector6for detecting a secondary particle from the wafer by applying a focused ion beam (FIB)4or the electron beam8to the wafer21, the movable sample stage24on which the wafer21is placed, a sample stage controller25for controlling a position of the sample stage for determining a desired sample position, a manipulator controller15for moving a tip of a probe72to an extracting position of a minute sample, extracting the minute sample and controlling a position or direction optimum for observation and evaluation of a determined position of the minute sample by applying the focused ion beam4(FIB) or electron beam8to the minute sample, an X-ray detector16for detecting an atomic property X-ray excited at the time of applying the electron beam8, and a deposition gas supplying device17.

Next, an outline of the process of sample processing, observation and evaluation after introducing the wafer in this embodiment will be described. The sample stage is first lowered and the probe72is horizontally (in X and Y directions) moved relative to the sample stage24with the tip of the probe72separated from the wafer21, and the tip of the probe72is set in a scanning area of the FIB4. The manipulator controller15which is a mechanism for operating the probe stores a positional coordinate and then evacuates the probe72.

The focused ion beam optical system31apples the FIB4to the wafer21to form a rectangular U-shaped groove across an observation and analysis position p2as shown inFIG. 4. Aprocessing area has a length of about 5 μm, width of about 1 μm and depth of about 3 μm, and is connected to the wafer21at its one side surface. Then, the sample stage24is inclined, and an inclined surface of a triangular prism is formed by the FIB.4. In this condition, however, the minute sample22is connected with the wafer21by a support portion S2.

Then, the inclination of the sample stage24is returned, and thereafter, the probe72at the tip of the manipulator70is brought into contact with an end portion of the minute sample22. Then, the deposition gas is deposited on a contact point75by application of the FIB.4, and the probe72is joined to and made integral with the minute sample22. Further, the support portion S2is cut by the FIB.4to cut out the minute sample22. The minute sample22is brought into a condition of being supported by the probe72, and ready is completed that a surface and an inner section of the minute sample22for the purpose of observation and analysis is taken out as an observation and analysis surface p3.

Next, as shown in FIG.5(b), the manipulator70is operated to lift the minute sample22up to a level apart from the surface of the wafer21. If necessary, the observation section p3of the minute sample22may be additionally processed to a desired shape by appropriately adjusting the application angle of the FIB4with rotating operation of the manipulator. As an example of the additional processing, there is a finishing processing for forming an observation section p2slantingly formed by tapering of the beam of the FIB4to be a real vertical section. In section processing/observation having been performed hitherto, an observation surface has to be a side wall of a hole dug by the FIB, while in the apparatus of this embodiment, the sample can be additionally processed after being lifted, with the observation surface thereof appropriately moved. Therefore, it becomes possible to form a desired section appropriately.

Then, the minute sample22is rotated, and the manipulator70is moved in such a manner that the electron beam8of the electron beam optical system41substantially vertically enters into the observation section p3to control attitude of the minute sample22, and then stopped. Thus, even in case of observing a section of the sample, detection efficiency of a secondary electron by the secondary particle detector6is increased as much as in the case of observing an outermost surface of the wafer. Observation condition of the observation and analysis surface p3of the minute sample22is greatly improved. A reduction in resolution which has been a problem in the conventional method can be avoided. The angles of the observation and analysis surfaces p2, p3can be adjusted to desirable angles, and therefore, it becomes possible to perform more exact observation and analysis. With this, direction of observation of the inner section of an object sample can be freely selected. Consequently, there can be provided a minute sample processing and observation apparatus which permits observing a shape and dimension of etching or planarization, an implanting condition, coating thickness or the like with high resolution by substantially vertically observing the section, and achieving measurement and evaluation with high accuracy.

In this embodiment, the resolution can be improved by transferring a minute sample by movement of the manipulator70immediately below the electron beam optical system41to reduce a working distance. In an apparatus, like this embodiment, in which an ion beam optical system and an electron beam optical system are disposed in one vacuum container, a space in the vacuum container is limited, and it is difficult to bring a large sample close to the electron beam optical system. However, by positioning a cut-out minute sample below the electron beam optical system as is in this embodiment, such a problem can be solved.

Further, the minute sample22is observed and analyzed while being placed in the sample chamber of a vacuum atmosphere without taken out of the apparatus, so that observation and analysis of the inner section of the sample to be observed and analyzed can be achieved with high resolution, high accuracy and an optimum angle without contamination or deposition of foreign materials resulting from exposure to the outside atmosphere. In addition, observation and analysis can be achieved with high throughput of processing more than a few positions per hour. This method also allows observation to be carried out simply by lifting and appropriately positioning the minute sample, which permits facilitating operation and reduction in operation time.

In this embodiment, the section of the semiconductor sample cut by FIB application is moved substantially perpendicularly to the optical axis of the scanning electron microscope to be observed. Thus, an extremely meritorious effect is exerted in such a case of observing a thin film layer formed in the semiconductor sample. For example, wiring formed in the semiconductor wafer has been often formed from copper or the like these days. Metal such as copper tends to be diffused in the semiconductor wafer to degrade the property of the semiconductor, so that it is necessary to form a barrier metal around the wiring to prevent diffusion. The barrier metal is an extremely thin film with a thickness on the order of 0.01 μm to 0.02 μm when the wiring has a thickness of 0.1 μm to 0.2 μm, and is formed from metal such as tantalum. In an inspection process of the semiconductor wafer, whether a barrier metal is formed appropriately or not is an important inspection item.

When the electron beam is slantingly emitted with respect to the observation section as in the conventional section processing and observation, a distance that the electron beam interferes in the sample is increased to reduce the resolution of the scanning electron microscope and to sometimes make it difficult to observe the barrier metal. Further, since the barrier metal is the thin film as described above, the electron beam entering into the barrier metal sometimes interferes adjacent other material areas. In such a case, there is a possibility of detecting information on other materials from a position where materials constituting the barrier metal only should exist. Thus, information on the copper of the adjacent wiring is detected regardless of the barrier metal being appropriately formed, which leads to a possibility of obtaining an inspection result that function as the barrier metal is not effected. This presents a problem especially in an EDX analysis for analyzing composition of a sample by detecting a property X-ray specific to material which is resulted from the electron beam application.

The metal which forms the wiring or barrier metal is sometimes corroded or oxidized at its surface when made in contact with the air, thus making it difficult to observe the section.

In this embodiment, for solving the above two problems together, observation by the scanning electron microscope capable of non-destructive observation with high resolution can be achieved in a vacuum atmosphere where the sample is cut out, and the electron beam application perpendicularly to the sample section is permitted. With this structure, it become possible to carry out section processing and observation of the semiconductor element which is becoming increasingly more minute with high resolution and accuracy.

Further, also in a case an additional processing is effected after observation by the scanning electron microscope, the minute sample can be positioned below the optical axis of the FIB without being exposed to the air. Therefore, there is no possibility that a position to be additionally processed is hidden by the oxide film and alignment of processing positions becomes impossible.

Further, in this embodiment, the minute sample22having the observation and analysis surface p3can be inclined or moved in various ways by the manipulator70. Thus, it becomes possible, for example, to provide a hole in the observation section p2and to also confirm three-dimensional fault forming condition in the sample.

In the example shown inFIG. 3, the manipulator70and the electron beam optical system41are provided opposite to each other with respect to the FIB4. However, in order to reduce the number of operation of the manipulator70or the like to minimize processing/observation time, it is preferable that a relative angle between the manipulator70and the electron beam optical system41is set close to 90° in a surface perpendicular to the application direction of the FIB4. The reason is that by setting so, it is sufficient that the manipulator70simply carries out an operation of lifting the minute sample22from the wafer21, operation of rotating the probe72in such a manner that the observation section p2is perpendicular to the electron beam8, and other fine adjustment operations.

Used in the above description is an example of lifting the minute sample22from the wafer21by the manipulator70, but not limited to this. The wafer21may be lowered to thereby consequently lift the minute sample22. In this case, the sample stage24is provided with a Z-axis moving mechanism for moving the wafer21in a Z direction (an optical axis direction of the FIB4). With this structure, it becomes possible to perform cutting out and lifting of the minute sample22in a condition where the optical axis of the electron beam optical system41is located in the portion of the wafer21to be the minute sample22. In this case, the process from cutting out the minute sample22by the FIB4to observing the observation section p2can occur with confirmation by the electron microscope without frequent changes of electron beam application positions during the process.

By the electron beam optical system41, an electron microscope image of the surface of the wafer21slantingly viewed can be obtained. A section to be processed or processing arrival position by the FIB4is superposed on the electron microscope image to be model displayed, then the section processing condition by the FIB4can be easily confirmed. In order to display the section to be processed in a superposed manner on the electron microscope image, animation showing a portion to be a section is displayed on the electron microscope image in the superposed manner based on a processing depth to be set and a dimension in the electron microscope image calculated from magnification.

If the processing depth is calculated in real time based on current and acceleration voltage of the FIB, material of the sample and the like, and an animation showing the present processing depth are displayed in an interposed manner on the electron microscope image, it becomes easy to confirm progress of the processing. The electron beam optical system41of this embodiment is disposed in a bird's eye position with respect to the wafer21, and the electron micro-scope image becomes a bird's eye image. Therefore, by displaying also the above-described animation into three-dimensional display together with the electron microscope image, it is possible to confirm the processing condition more clearly.

Further, this embodiment has a function of setting a position of the section processing on a scanning ion microscope image (SIM image) formed on the basis of the secondary electron obtained by scanning the wafer21with the FIB. However, it is possible to provide also a sequence where other setting and operation of the apparatus (driving of the sample stage and determination of the processing position by the ion beam) are automatically carried out based on inputs of the section position and the processing depth. In this case, a portion to be an upside of the observation section p3is first designated on the SIM image, and the processing depth (a dimension in the depth direction of the observation section p3) is set. Based on these two settings, the forming angle of the inclined portion of the minute sample22and the observation and analysis surface p3are automatically determined, and the subsequent processing is automatically carried out by the settings. It is also possible to provide a sequence where the subsequent processing is automatically carried out by setting the observation and analysis surface p3(rectangular area) on the SIM image and setting the processing depth.

In this embodiment, after the minute sample22is lifted, the probe72is operated so that the observation section p3is appropriately positioned with respect to the electron beam8. InFIG. 4, for example, when simply rotating the probe72, the minute sample22is rotated around an attachment point to the probe72. Therefore, the observation section p3includes components of not only a rotation around a longitudinal axis of the minute sample22but also a rotation around an axis in the application direction of the FIB4. Imparting a mechanism for removing the rotational components to the manipulator or manipulator controller, and operating the manipulator in timing compliant with the rotation of the probe72or timing different from the rotational operation allow the observation section p3to be accurately positioned in a surface perpendicular to the optical axis of the electron beam8.

The same effect can be obtained by disposing the probe72to have an angle slightly larger than 90° to the electron beam optical system41in the surface perpendicular to the optical axis of the FIB4. In this case, the effect is achieved by disposing the probe72to a rotational component around the axis in the application direction of the focused ion beam plus 90° with respect to the electron beam optical system41.

Including the rotational component around the axis in the application direction of the FIB4is resulted from the rotation axis of the probe72being inclined with respect to the observation and analysis surface p2and the observation section p3. That is, the above problem can be solved by forming the probe72such that the rotation axis becomes parallel to the observation and analysis surface p2and observation section p3. Therefore, in a case of the apparatus having a mirror structure as shown inFIG. 3, the rotation axis of the probe72is preferably formed in parallel with the surface of the wafer21(perpendicular to the optical axis of the FIB4). By curve the tip of the probe72, even a probe having the rotation axis parallel to the surface of the wafer21can support the minute sample22. Further, it is preferable to form the rotation axis of the probe72so as to be perpendicular to the electron beam optical system41so that the sample can be moved below the optical axis of the electron beam8by rotation and parallel movement of the probe. Specific examples of the structure of the probe will be further described in detail in a description on a subsequent embodiment.

If a mechanism to transfer a driving power from the manipulator controller15to a probe having a rotation axis with a different height from a probe holder71and parallel to the wafer21is provided, alignment of the observation section p3with the electron beam8can be carried out without moving the minute sample22on a large scale.

The minute sample22in a suspended condition by the probe72is susceptible to vibration, thus in observation and analysis with high magnification and in a locating environment of much vibration, the minute sample22may be grounded on a safe position on the wafer21or grounded on a minute sample port provided on a space around the wafer on the sample stage to thereby substantially restrain the vibration of the minute sample, permitting superior observation and analysis.FIG. 18shows an example thereof such that earthquake resistance is improved by grounding the cutout minute sample22on the wafer21. In adopting such a method, it is preferable to make a sequence in advance such that the grounding position of the minute sample matches the optical axis of the electron beam8.

In creating the minute sample22shown inFIG. 4, the minute sample22is processed into pentahedron. This achieves creating of the minute sample especially with reduced waste in processing and in a reduced period of time for separation of the minute sample. It is needless to say that the same effect of the present invention can be obtained by forming the minute sample22into tetrahedron (not shown) or a shape close to tetrahedron which can minimize processing time because of the least processing surface.

In the EDX analysis in which the electron beam8is scanned on the minute sample22, elementary analysis accuracy is improved by forming the minute sample22thinner in the electron beam application direction than an entry distance of about 1 μm by the electron beam application. The EDX analysis is carried out using a detector of an X-ray generated from the minute sample resulting from the electron beam application. Forming the minute sample to be a thinner film permits avoiding enlargement of an X-ray generation area resulting from entry of a charged particle beam, thus enabling the elementary analysis with high resolution.

By applying the analysis thus far described to the semiconductor wafer with or without pattern, the analysis can be used in an inspection of a semiconductor manufacturing process to contribute to improvement of manufacturing yield by early detection of failure and quality control in a short period of time.

A structure and an operation of a minute sample processing and observation apparatus according to a second embodiment of the present invention will be described with reference toFIGS. 6 and 7.FIG. 7is a plan view ofFIG. 6, and there are some differences between the figures in orientations or details of apparatuses for convenience in description but they are not essential differences. In this apparatus, a focused ion beam optical system31is vertically disposed and a second focused ion beam optical system32is located at an angle of approximately 40° at the upper part of a vacuum sample chamber60disposed in the central part of the apparatus system. An electron beam optical system41is slantingly located at an angle of approximately 45°. Three optical systems31,32,41are adjusted in such a manner that their respective central axes intersect at a point around a surface of a wafer21. Similarly to the apparatus of the first embodiment, inside the vacuum sample chamber60is located a sample stage24on which the wafer21to be a sample is placed. The sample stage24in this embodiment has functions of horizontal (X-Y), rotational and vertical movements, but a slanting function is not necessarily required.

Next, a sample creating operation by this apparatus will be described with reference to FIG.4. An FIB4is applied from the focused ion beam optical system31to the wafer21to form a rectangular U-shaped groove across an observation and analysis position p2as shown in FIG.4. This is identical to the first embodiment. Then, an inclined surface of a triangular prism is formed by processing with the FIB4from another focused ion beam optical system32. In this condition, however, the minute sample22and wafer21are connected with each other by a support portion. Then, a minute sample is cut out using the FIB4from the focused ion beam optical system31similarly to the first embodiment. That is, a probe72at a tip of a probe holder71of a manipulator70is brought into contact with an end portion of a minute sample22, and then deposition gas is deposited on a contact point75by application of the FIB4, where the probe72is joined to and made integral with the minute sample22, and the support portion is cut by the FIB4to cut out the minute sample22. Subsequent steps of observation and analysis of the minute sample22are identical to the first embodiment.

As described above, also in this embodiment, high speed observation and analysis with high resolution can be achieved similarly to the first embodiment. In this embodiment, slanting of the sample stage can be eliminated especially by using two focused ion beam optical systems. Omitting the slanting mechanism of the sample stage can improve positioning accuracy of the sample stage more than a few to ten times. In a manufacturing site of LSI devices, it has come into practice in recent years that various wafer inspection and evaluation apparatus carry out a foreign material inspection and defect inspection, that a property and coordinate data of a wrong portion on the wafer are recorded, and that subsequent apparatus for a further detail inspection receives the coordinate data to determine a designated coordinate position and to carry out observation and analysis. High positioning accuracy permits automation of determining the observation position of the wafer21and simplification of its algorithm. This can substantially reduce required time, which permits obtaining high throughput. Further, the sample stage having no slanting mechanism is compact and lightweight and can easily obtain high rigidity to increase reliability, thus permitting superior observation and analysis and miniaturization or a reduction in cost of the apparatus.

Imparting a swinging function to the focused ion beam optical system31to be appropriately moved between the vertical and inclined positions permits processing identical to the second embodiment without slanting the sample stage24, and thus the effect of the present invention can be obtained.

A structure and an operation of a minute sample processing and observation apparatus according to a third embodiment of the present invention will be described with reference toFIGS. 8 and 9.FIG. 9is a plan view ofFIG. 8, and there are some differences between the figures in orientations or details of apparatuses for convenience in description but they are not essential difference. In the apparatus of this embodiment, a focused ion beam optical system33is slantingly located at an angle of approximately 45° at an upper portion of a vacuum sample chamber60disposed at the central part of the apparatus system. An electron beam optical system42is also slantingly located at an angle of approximately 45°. Two optical systems33,42are adjusted in such a manner that their respective central axes intersect at a point around a surface of a wafer21. Similarly to the apparatus of the first embodiment, inside the vacuum sample chamber60is located a sample stage24. Further, similarly to the second embodiment, the sample stage24has no slanting function.

Next, processes of sample processing, observation and evaluation after introducing the wafer will be described with reference toFIG. 19also. The sample stage is first lowered to move a probe72horizontally (in X and Y directions) relative to the sample stage24with the tip of the probe72separated from the wafer21, and the tip of the probe72is set in a scanning area of the FIB4. The manipulator controller15stores a positional coordinate and then evacuates the probe72.

The sample stage is oriented in such a manner that an intersection line of a vertical plane containing an optical axis of a focused ion beam optical system33and a top surface of the wafer is superposed on an observation section of a sample to be formed. Then, an FIB4is applied to the wafer21for scanning to form a vertical section C1having a length and depth required for the observation. Then, an inclined cut section C2which intersects a formed section is formed. When forming the inclined cut section C2, the sample stage is rotated around a horizontal axis up to a position where an inclination angle of an inclined surface is obtained to determine the orientation. Next, an inclined groove is formed by the FIB4in parallel with a vertical cut line. Further, an end C3is cut orthogonal to the groove. A processing area has a length of about 5 μm, width of about 1 μm and depth of about 3 μm, and is connected to the wafer21in a cantilevered condition of a length of about 5 μm. Then, the probe72at the tip of a manipulator70is brought into contact with an end portion of a minute sample22, and then deposition gas is deposited on a contact point75by application of the FIB4, where the probe72is joined to and made integral with the minute sample22. Then, the other end C4supporting the minute sample is cut by the FIB4to cut out the minute sample22. The minute sample22is brought into a condition of being supported by the probe72, and ready to be taken out with a surface and an inner section for the purpose of observation and analysis as an observation and analysis surface p3is completed. Processing thereafter is substantially identical to the first embodiment except that an orientation of the sample stage24is also required to be appropriately adjusted when setting the optimum orientation of the minute sample for processing and observation by the focused ion beam optical system or observation by electron beam optical system, and thus description thereof will be omitted.

As described above, also in this embodiment, high speed observation and analysis with high resolution can be achieved similarly to the first embodiment. This embodiment has a feature that one focused ion beam optical system is inclined with respect to the sample stage to thereby cut out and extract the minute sample from the wafer without imparting a slanting function to the sample stage. Generally, a large number of devices are required to be mounted around the optical system, causing lack of spaces, and a large total mass of the devices makes difficult design of a mounting substrate including ensuring rigidity. Maintenance thereof is also a matter of concern. This embodiment eliminates the need for a slanting mechanism of the sample stage, and requires only one focused ion beam optical system, which can provide a simple, compact and lightweight structure and reduced cost.

An outline of structure of a minute sample processing and observation apparatus according to a fourth embodiment of the present invention will be described with reference to FIG.10. In this embodiment, a second sample stage18and second sample stage controller19for controlling an angle, a height and the like of the second sample stage are added to a basic structure of the minute sample processing and observation apparatus shown in FIG.3. The process from applying an ion beam from the focused ion beam optical system31to a wafer to extracting a minute sample from the wafer is identical to the first embodiment. In this embodiment, the extracted minute sample is fixed to the second sample stage for observation and analysis instead of observation and analysis in the supported condition by the manipulator.

FIG. 11shows a condition of the minute sample22fixed to the second sample stage18. A member with a flattened surface is used for a minute sample fixed portion of the second sample stage18in this embodiment, but flatness does not matter. A bottom surface of the minute sample is brought into contact with the second sample stage18, and deposition gas is deposited on a contact point between the second sample stage18and minute sample22with the FIB4to fix the minute sample22to the second sample stage18with an assist deposition film76. In order to prevent inconvenience of attachment of foreign materials to the surface of the observation section or destruction of the surface of the observation section when creating the minute sample22or depositing the deposition gas, an application angle of the FIB4may be appropriately set in parallel to the observation section of the minute sample by operating the second sample stage to create a desired observation section by applying the FIB4.

By locating the second sample stage shown inFIG. 12, a plurality of minute samples can be collectively handled. By repeating operation of extracting the minute sample22from the wafer21to fix it to an appropriate position on the second sample stage18beside the first sample stage, section observation and elementary analysis of the plurality of samples can be carried out with the wafer21fixed to the sample stage24, and distribution of a section structure throughout the wafer21can be efficiently examined.

InFIG. 12, when fixing the plurality of minute samples in a line to the second sample stage18and carrying out observation and analysis in a condition where both of a stopping orientation of the sample stage24and an angle of the second sample stage18are adjusted so as to locate the minute sample22at an appropriate angle to the electron beam8, the plurality of minute samples can be observed and analyzed successively or repeatedly with compared to one another, thereby permitting detailed and efficient examinations of the section structure and elementary distribution throughout the wafer21. The second sample stage18shown inFIG. 13is a rotatable column sample stage such that a minute sample group can be arranged on its outer peripheral surface, and a larger number of minute samples can be handled at a time than in the case of FIG.12.

By detaching the minute samples22to be recovered in a designated position in a sample recovery tray and providing identification means for the minute samples, the minute samples22can be taken out again for observation and analysis when a detailed evaluation is required afterward.

As described above, also in this embodiment, secondary electron detecting efficiency can be obtained as high as in the case of observing the wafer surface, an angle for observation and analysis can be adjusted to a desirable angle including vertical observation, observation can be carried out with placed in a sample chamber of a vacuum atmosphere, and the like, therefore, observation condition of the minute sample22is greatly improved to permit avoiding a reduction in resolution which has been a conventional problem and carrying out optimum, exact observation and analysis promptly with high speed and high efficiency. As a result, superior observation and analysis can be carried out with high throughput. By separating the minute sample from the manipulator to be fixed to the second sample stage, vibration isolating mechanism of the sample stage which holds the introduced sample and vibration isolating mechanism of the second sample stage to which the minute sample is fixed can be shared.

Details of the probe for lifting the minute sample from the wafer, which has been described in the former embodiments and a driving mechanism for driving the probe will be described below.FIG. 16is an explanatory view of the embodiment. In this embodiment, an example where the probe for lifting the minute sample from the wafer and the like and a holder for holding the probe are detachably mounted to a sample chamber (vacuum container) will be described.

An optical system226comprising an ion source225, beam limiting aperture228, focusing lens229, deflector230and objective lens231are basically the same as inFIG. 3, and an FIB227is adjusted which is applied along an optical axis224. Further, the apparatus shown inFIG. 16is provided with a sample holder233afor holding a wafer217and a stage234for moving the sample holder in X-Y directions.

The apparatus is further provided with a secondary electron detector237for detecting a secondary electron discharged from the sample resulting from application of the FIB227, a deposition gas source238for blasting a deposition gas concurrently with application of the ion beam and a vacuum container206for maintaining high vacuum in the sample chamber. An output of the secondary electron detector237is amplified by an amplifier (not shown) and then stored in an image memory (not shown) and displayed on an image display apparatus238. A central processing unit240controls various components of the apparatus shown inFIG. 16via an FIB controller236, a probe position controller223, and stage position controller235.

Details of a probe moving mechanism201(manipulator) which is controlled by the probe position controller223will be described with reference toFIGS. 17 and 18. An air lock chamber202provided in the probe moving mechanism201is coupled to a base flange205via bellows204absorbing a moving amount of a probe203. The base flange205is fixed to a vacuum container206with a vacuum seal207interposed therebetween. A closable air lock valve208is disposed at an end of the air lock chamber202, and opened/closed by rotating a cylindrical air rock valve opening/closing mechanism209. Shown inFIG. 17is a condition where the air lock valve208is opened and a probe holder210is introduced into the vacuum container206in such a manner that its central axis is inclined to a surface of the wafer217. An air rock chamber outer cylinder211in which the air lock valve208and air rock valve opening/closing mechanism209are accommodated has a concentrical hollow double structure, and one end of the hollow portion communicates with the air lock chamber202and the other end communicates with an exhaust pipe212. The above structure eliminates the need for compact bellows for the air lock chamber202which has been conventionally required, permitting simplification, miniaturization and reduction in cost of the probe moving mechanism201.

On a fixed side flange213of the bellows204, a current introduction terminal214having a sealing function is disposed. By connecting via a lead wire216a vacuum side of the current introduction terminal214to a probe holder249which holds the probe203and is formed from an insulating material with conduction at portions in contact with the probe203and probe holder stopper215, power can be supplied from an air side to the probe203.

To one end of the air rock chamber outer cylinder211, a Y-axis stage219ais fixed where a Y-axis linear guide218ais fixed in parallel with the surface of the wafer217as shown, and coupled to a Y-axis base220via the Y-axis linear guide218aas shown in FIG.18. Linear driving of a Y-axis is carried out using a Y-axis linear actuator221aheld by the Y-axis base220. An output shaft of the Y-axis linear actuator221ais coupled to a Y-axis stage219avia a Y-axis lever222a. The Y-axis base220is coupled to a Z-axis stage219b.

The Z-axis stage219bis coupled to an X-axis stage219cvia a Z-axis linear guide218bdisposed perpendicularly to the surface of the wafer217having a phase 90° different from the Y-axis linear guide218aas shown. The linear driving of the Z-axis stage219bis carried out using a Z-axis linear actuator221bheld by the X-axis stage219c. An output shaft of the Z-axis linear actuator221bis coupled to the Z-axis stage219bvia a Z-axis lever222b.

Similarly, the X-axis stage219cis coupled to the base flange205via an X-axis linear guide218cdisposed in parallel with the surface of the wafer217having a phase 90° different from the Y-axis linear guide218aas shown. The linear driving of the X-axis stage219cis carried out using an X-axis linear actuator221cheld by the base flange205. An output shaft of the X-axis linear actuator221cis coupled to the X-axis stage219cvia an X-axis lever222c.

As described above, coupling the X-, Y- and Z-axes to the respective linear actuators via the respective levers can eliminate projections at the linear actuators and achieve miniaturization of the probe moving mechanism201. The probe moving mechanism201of this embodiment has a width of 172 mm in the X-axis direction and a height of 165 mm in the Z-axis direction which are substantially identical to the width and height of the used linear actuator.

Introduction of the probe holder210into the vacuum container206according to this embodiment adopts the following procedures. The probe holder210is inserted in front of the air lock valve208. In this condition, the air lock chamber202is kept to be sealed by the vacuum seal207arranged in an outer cylinder of the probe holder210. After the insertion, air in the air lock chamber202is exhausted to be a vacuum from the exhaust pipe212through a hollow portion of the air lock chamber outer cylinder211. After confirming that a pressure in the air lock chamber202reaches a predetermined pressure, the air lock valve208is opened using the air lock valve opening/closing mechanism209, and the probe holder210is introduced into the vacuum container206. The above described operations allow the probe203to be introduced into the vacuum container206without the vacuum container206being exposed to the air.

Extracting the probe holder210from the vacuum container206can be carried out by the procedure in the reverse order of the insertion. That is, the probe holder210is once extracted in front of the air lock valve208, then the air lock valve208is closed using the air lock valve opening/closing mechanism209. Confirming the closure, the air in the air lock chamber202is leaked from the exhaust pipe212. After confirming an atmospheric pressure, the probe holder210is taken out of the probe moving mechanism201. Adopting the above structure allows replacement of the probe203which is a consumable supply to be carried out without the vacuum container206being exposed to the air.

As shown inFIG. 16, by structuring the probe holder210in such a manner that a substantially central axis of the probe holder210enters slantingly to the wafer217(in this embodiment, enters at an angle of 30°), the probe holder210can reach near the optical axis224of the charged particle beam optical system with a minimum length, which permits providing the probe holder210with high rigidity and remarkably facilitating handling of the few μm sample piece232and operations of making the tip of the probe into contact with a predetermined position on an electron element having a submicron wiring.

Machine parts such as the bellows204for absorbing the mounting amount of the probe203are not positioned lower than the surface of the wafer217, so that the probe moving mechanism201has no influence on the size of the vacuum container206, and the vacuum container206may be a minimum size determined within a movement range of the wafer217. Minimizing the vacuum container206which determines the size of the apparatus can provide a sample creating apparatus for samples with large diameters mounted with a probe moving mechanism, which permits reduction in occupying area, weight and cost and also miniaturization of exhaust means. In this embodiment, the entering angle of the probe holder210is 30°, but not limited to this. The same effect can be obtained by inserting the probe holder210slantingly to the vacuum container206in such a manner that the probe203is within a range of being displayed by the image display apparatus238.

By arranging the probe moving mechanism201in a position where a distance to the intersection point of the center of the base flange205which couples the probe moving mechanism201to the vacuum container206and a vertical line of the optical axis224is below ½ of the horizontal movement range of the sample stage234, below 150 mm in this embodiment, the probe holder210can be introduced into the vacuum container206with a minimum length at a desired angle, and freedom of a layout of the apparatus can be increased while permitting the vacuum container206to be miniaturized. Moreover, by adopting the structure where the respective linear actuators of the probe moving mechanism201slantingly entering in the vacuum container206and the respective stages are coupled via the levers, the probe moving mechanism201can eliminate projections, thus imposing no limitation in the layout to other measurement instruments arranged in the vacuum container206, preventing problems of unexpected interference or the like and achieving miniaturization of the apparatus.

Creating the sample using this apparatus is carried out by the following procedures. The ion beam227emitted from the ion source225is focused on a predetermined position on the stage234by passing through the optical system226. The focused ion beam, that is, FIB227is spattered in the form of scanning the surface of the wafer217to carry out fine processing of the sample piece (not shown). On the stage234, the wafer217and the sample holder233afor holding the extracted sample piece are placed, and the stage position controller235determines a position to be FIB processed and extracted.

The probe203mounted on the probe moving mechanism201is moved to an extracting position on the wafer217independently of the stage234by the probe position controller223. Operations of movement and processing are carried out while observing by scanning with the FIB around the extracting position of the wafer217by the FIB controller236, detecting the secondary electron from the wafer217by the secondary electron detector237, and displaying the obtained secondary particle image on the image display apparatus238.

For extracting the sample piece, the FIB processing is carried out while changing the attitude of the wafer217to cut out the sample piece in the form of a wedge, and deposition gas is supplied to the contact portion of the sample piece where the probe203is made into contact with using the deposition gas source239, and an ion beam assist deposition film is formed to thereby attach the probe203to the sample piece. The prove203is then raised from the wafer217by the probe position controller223, and moved to a position of the sample holder233bon the stage234. The probe203is lowered, contact between the wedge portion of the sample piece attached to the probe203and the surface of the sample holder233bis confirmed, and a side surface of the sample piece is attached to the sample holder233aby the ion beam assist deposition film. The tip of the probe203is cut from the sample piece232by the FIB and moved to a next sample extracting position by the probe position controller223.

The above processes make it possible to extract the sample piece232at a desired position from the wafer217and move it to the sample holder233b. The above operations are collectively controlled by a central processing unit240. This embodiment adopts the ion beam assist deposition film as the attaching means between the probe203and the sample piece232, but there is no problem in electrostatic attaching means using an attaching force by static electricity, and the same effect can be obtained as this embodiment in that case. However, attachment by the assist deposition film is desirable for attaching the probe to the accurate position.

In this embodiment, the probe moving mechanism is structured to be slantingly inserted, thereby permitting miniaturization of the sample chamber (vacuum container) in comparison with a probe moving mechanism which is inserted horizontally of the wafer surface disclosed in JP-A-11-56602 specification. For example, when the sample is the semiconductor wafer with the large diameter and the probe moving mechanism is tried to be horizontally introduced, the machine parts such as bellows for absorbing the moving amount of the probe are inevitably positioned lower than the surface of the wafer, therefore the machine parts have to be placed in a position which has no interference with the stage on which the wafer is placed, that is, out of the movement range of the stage. This inevitably causes upsizing of the vacuum container, but the present invention can achieve miniaturization of the vacuum container, and the resultant reduction in an occupying area and cost and miniaturization of a vacuum exhaust pump.

There have been needs for extending the probe from the side wall of the vacuum container to the predetermined position (around the optical axis of the charged particle beam) and thereby providing a long support member for supporting the probe, causing a problem of degraded rigidity. This embodiment can also solve the problem to thereby facilitate positioning the prove in the predetermined position.

FIG. 19is a sectional view of a sample creating apparatus of a sixth embodiment using a slantingly entering sample stage fine moving device241. Described in the former embodiment has been the example of providing an electron beam barrel in the same sample chamber as the ion beam barrel and observing the sample cut out by the electron beam barrel. However, described in this embodiment is an example of transferring a cut-out sample to other analyzer using a side entry type sample stage and observation is carried out. The side entry type sample stage means a stage to be inserted from the side of a charged particle beam barrel or the sample chamber, and details thereof will be described below.FIG. 20is an enlarged view of portions around the probe203inFIG. 19, andFIG. 21Ais a vertical sectional view andFIG. 21Bis a horizontal sectional view of a side entry type sample stage242used in FIG.19.

First, the side entry type sample stage242will be described with reference toFIG. 21. Asample locating portion243to which a sample piece232is attached is held by a sample holder233a. A projection245is provided on an end surface of a driving shaft244side of the sample holder233a. The shape of the projection245does not matter. Arranged in a position on an end surface of a vacuum side of the driving shaft244is a rotation shaft246, of which free end is eccentric from a rotational central axis of the driving shaft244, in contact with a surface of the projection245with an attitude in parallel with the central axis of the driving shaft244. When a knob247of the driving shaft244is rotated, the rotation shaft246is eccentrically rotated and the projection245with which the free end of the rotation shaft246is in contact is rotationally moved around a rotation bearing273depending on an eccentric amount and a rotation amount of the rotation shaft246. That is, the sample holder233ais rotationally moved. In this embodiment, rotation at 230° is possible. A part of an outer cylinder248of the sample holder233aportion is cut out and it facilitates attachment of the sample piece232to a sample locating portion243and forming of the sample piece232by the FIB. Using the same mechanical system and control system as the probe moving mechanism201shown inFIGS. 17 and 18for a sample stage fine moving mechanism241for driving the side entry type sample stage242and a sample stage position controller278improves productivity and reduces cost of the apparatus, and also improves maintainability and operability.

Sample creation using the sample creating apparatus according to this embodiment takes the following steps. The operations of introducing and extracting the side entry type sample stage242into and from the vacuum container206are the same as the operations of the probe holder210in the above described probe moving mechanism201.

Before extraction of the sample piece232at a desired position from the wafer217, the same processes as the fifth embodiment are adopted. After extraction of the sample piece232, the side entry type sample stage242is inserted into the vacuum container206without being exposed to the air. In this case, similarly to the fifth embodiment, by structuring the side entry type sample stage242in such a manner that a substantially central axis of the side entry type sample stage242slantingly enters with respect to the wafer217, the size of the vacuum container206can be minimized, and the side entry type sample stage242can reach near an intersection point of the optical axis224of the FIB227and the wafer217with a minimum length. In this embodiment, the side entry type sample stage242slantingly enters at an angle of 30° to the surface of the wafer217, but not limited to 30°. The same effect can be obtained by slantingly inserting the side entry type sample stage242into the vacuum container206in such a manner that the sample holder233aexists within a range of being displayed by an image display apparatus238.

By this structure, from the same reason as the probe moving mechanism201in the fifth embodiment, the sample stage fine moving mechanism241has no influence on the size of the vacuum container206and the vacuum container206can be a minimum size which is determined by a movement range of the wafer217. By arranging the sample stage fine moving mechanism241in a position where a distance to an intersection point of a center of the base flange205which couples the sample stage fine moving mechanism241to the vacuum container206and a vertical line of the optical axis224is below ½ of the horizontal movement range of the sample stage234, below 150 mm in this embodiment, the side entry type sample stage242can be introduced with a minimum length at a desired angle, and freedom of a layout of the apparatus can be increased while permitting the vacuum container206to be miniaturize.

After insertion of the side entry type sample stage242, the knob247is turned to rotate the sample locating portion243held by the sample holder233aat an angle in parallel with the wafer217as shown inFIG. 20, that is 30° in this embodiment. Then, the probe203holding the sample piece232is driven by the probe moving mechanism201and the probe position controller223shown inFIG. 19, and the minute sample piece232is attached to the sample holder233aby forming a deposition film. After attachment, the sample holder233ais again rotated to the position in parallel with the axis of the side entry type sample stage242, and the side entry type sample stage242is then extracted from the vacuum container206by the above described means, and for example, mounted to a TEM apparatus (not shown) to thereby carry out TEM observation. The rotation of the sample holder233ais used for fine rotational adjustment of the sample piece232in the TEM observation to permit more reliable analysis.

By adopting the structure according to this embodiment, the FIB apparatus can be realized which has the vacuum container206with the size restricted to the same size as in the fifth embodiment, the probe moving mechanism201which can extract the sample piece232at a desired position on the wafer217and the side entry type sample stage242which can be mounted to various analyzers. By using this FIB apparatus, it becomes possible to transfer the sample piece232at a desired position of the wafer217with a large diameter to the sample holder233ain the vacuum container206, and further, by taking out the side entry type sample stage242on which the sample holder233ais placed without being exposed to the air, prompt mounting on various analyzers and evaluation become possible. Further, by adopting a sample stage fine moving device with the same manner as the probe moving mechanism201, improvements of productivity, maintainability, and operability of an apparatus can be realized.

FIG. 22is a sectional view of a sample creating apparatus of still another embodiment. The embodiment differs from the sixth embodiment in that it uses a probe moving mechanism201having a probe holder210in which freedom of rotation around a Y-axis shown by the coordinate system shown inFIG. 16is added to a probe203shown inFIG. 23, and a sample stage fine moving mechanism in which freedom of rotation around a central axis of a side entry type sample stage242is added to a sample holder233ashown in FIG.24.

The structure of the probe holder210will be described with reference to FIG.23.FIG. 23Ashows the probe203in a projected condition, andFIG. 23Bshows the probe203accommodated in an outer cylinder248. The probe203is fixed to a probe holder249through a leaf spring252, and the probe holder249is held in an inner cylinder251which linearly moves through a bearing250. The inner cylinder251is inserted into an outer cylinder248with freedom in a rotating direction being limited, and pressed against a driving shaft253via a bearing254. An end of the probe holder249is connected to a helical compression spring259, and the other end of the helical compression spring259is coupled to the driving shaft253. A rotation center of the bearing250is inclined to a center line of the probe holder210at an insertion angle of the probe holder210. This allows the probe203to be rotationally moved in parallel with the surface of the wafer217in the vacuum container206. If such a probe is applied to the apparatus described in the first embodiment, observation by a scanning electron microscope capable of non destructive observation with high resolution becomes compatible with application substantially in a vertical direction to the sample section. As is the apparatus of the present invention, in an apparatus handling large samples, a probe and a moving mechanism of the probe must be disposed above the samples. However, the probe and the probe moving mechanism disclosed inFIG. 23permit rotation of a cut out minute sample around a rotation axis parallel to a sample surface.

The driving shaft253is inserted into the outer cylinder248with a bearing255for rotation and linear moving and a vacuum seal (not shown) interposed. An end of the driving shaft253projects from the outer cylinder248. A gear256bis fixed to the projected portion of the driving shaft253, and a minute feeding mechanism257which is an actuator of linear movement is pressed against an end surface of the driving shaft253. Another gear256ain mesh with the gear256bis arranged in parallel with the driving shaft253, and a knob247for rotary movement is fixed to the gear256a. It is needless to say that the gears256a,256bare held via rotatable members, though not shown. The above is the basic structure of the probe holder210having two degrees of freedom of rotation and accommodation of the probe203.

Next, operations will be described. The driving shaft253is linearly moved using the minute feeding mechanism257. The linear movement of the driving shaft253is transferred to the outer cylinder248, thus the probe203held by the probe holder210is linearly moved without rotation. By this structure, accidents such as damages of the minute probe203can be prevented in operations such as inserting or extracting the fine probe holder210into or from the vacuum container206, and an operator can easily use the apparatus.

The probe203is rotationally moved by turning the knob247, rotationally moving the driving shaft253via the gears256a,256b. Since freedom of rotation of the inner cylinder251is limited, the rotary movement of the driving shaft253does not cause rotary movement of the inner cylinder251. An elastic deformation by the helical compression spring259changes a direction of the rotary movement, but the rotary power is transferred to the probe holder249, and the probe holder249held via the inner cylinder251and bearing250for rotation is rotationally moved. As described above, by simple operations of linear and rotary movements of a single driving shaft253, the probe203can move linearly and rotationally.

Next, the fine moving mechanism of the side entry type sample stage242to which freedom of rotation is added will be described with reference to FIG.24. The respective moving mechanisms of the X-, Y- and Z-axes are of the same type as the probe moving mechanism201shown inFIGS. 17 and 18, and only different points will be described below.

In this embodiment, the difference from the sixth embodiment is that a gear261ais disposed on a grip260of a side entry type sample stage242, and a gear261bin mesh with the gear261aand a driving source262for rotatably driving the gear261bare disposed on a Y-axis stage219a. By the structure of this embodiment, the side entry type sample stage242can be inclined at a desired angle by rotationally moving the sample holder233aportion together with the whole side entry type sample stage242. Further, by using the gears261a,261bas transferring media of the rotary power, the gear261acoupled to the side entry type sample stage242can be coupled to the gear261bcoupled to the driving source262using no mechanical parts such as screws with no bars in inserting and extracting the side entry type sample stage242.

FIG. 25shows operations of processing the sample piece232by the sample creating apparatus of FIG.22. Sample creating by the sample creating apparatus of this embodiment will be described with reference to this figure. The same steps as the fifth embodiment are adopted before the step (a) for extracting the sample piece232from the wafer217.

When analyzing an outermost surface of the wafer217, as described in the sixth embodiment, the sample piece232is transferred on a sample locating portion243rotationally moved in parallel with the surface of the wafer217without rotating the probe203. When analyzing the wafer217in the depth direction, the sample piece232is extracted from the wafer217and then the probe203is rotated at an angle of 90°, and the X-, Y- and Z-axes are driven if necessary, and the sample piece232is attached by the ion beam assist deposition film to the sample locating portion243which has been rotationally moved in parallel with the surface of the wafer217(FIG.25(b)). After the sample piece232is transferred to the sample locating portion243, the probe203is linearly moved using the minute feeding mechanism257so as to be accommodated in the outer cylinder248. Then, the knob247is turned to reset the inclined sample holder233aholding the sample locating portion243(FIG.25(c)). Then, the driving source262is driven, and the sample holder233ais rotationally moved in such a manner that the sample locating portion243is opposed to the FIB227, and the sample piece232is forming worked by the FIB227(FIG.25(d)).

In this case, during the steps of processing, by rotating and inclining the sample holder233ato have a position in FIG.25(b), it is possible to observe the condition of the observation surface at any time through an image display apparatus238for displaying secondary particle images from the sample surface. After forming worked, it is possible to carry out analysis by extracting the side entry type sample stage242from the vacuum container206and mounting it as it is on an analyzer such as TEM.

According to the sample creating apparatus of this embodiment, analysis of the outermost surface layer and in the depth direction of the wafer217is possible, and further, a wide range of sample analyses is possible because of having the same structure as the side entry type sample stage242capable of being mounted to various analyzers, thereby greatly enlarging a range of utilization as the sample creating apparatus.

In the above embodiment, description has been made on creation and observation of the TEM sample as an example for convenience in description, but not limited to the TEM. It is apparent that the sample surface can be easily analyzed or observed by configuring the apparatus so as to be mounted to any one of the focused ion beam apparatus, transmission electron microscope, scanning electron microscope, scanning probe microscope, Auger electron spectroscopic analyzer, electron probe X-ray microanalyzer, electronic energy deficiency analyzer, secondary ion mass spectroscope, secondary neutron ionization mass spectroscope, X-ray photoelectron spectroscopic analyzer, or electrical measuring apparatus using a probe.

In the charged particle beam apparatus having the ion beam barrel and electron beam barrel as described in the first embodiment, the ion beam barrel and electron beam barrel are relatively inclined to the sample placing surface of the sample stage. The sample piece is separated from the sample placed on the sample stage by the ion beam, and is joined in an deposited manner by the ion beam and gas to a needle member mounted to the tip of the probe and is extracted. The extracted sample piece is moved below the electron beam rotated such that the electron beam can be applied to a predetermined portion. The secondary electron from the sample may be detected by the detector to obtain a scanning electron microscope image.

In the sample creating apparatus described above, the description has been made specially on the FIB227only for convenience in description, but the same effects can be obtained as the present invention even in, for example, a sample creating apparatus using a projection ion beam which is configured by replacing a deflector230and objective lens231with a mask plate and projection lens, or a sample creating apparatus using a laser beam which is configured by replacing an ion source225with a laser source. Moreover, there is no problem of making a sample creating apparatus having a structure in which an optical system of a scanning electron microscope is added to the above described sample creating apparatus. In that case, by using the probe moving mechanism201having freedom of rotation around the Y-axis shown in the seventh embodiment of the present invention, it becomes possible to observe the sample piece232with high resolution by opposing the sample piece232together with the probe to the optical system of the scanning electron microscope after the sample piece is taken out of the wafer217.

FIG. 26is a sectional view of an embodiment where a probe moving mechanism201according to the present invention is applied to a failure inspection apparatus. In the figure, an electron beam266emitted form an electron gun265passes through an electron beam optical system267and is focused on a surface of a wafer217placed on a stage234. The stage234is controlled by a stage position controller235to determine position of an element to be evaluated on the wafer217. In this figure, only two probe moving mechanisms201are shown, but another two probe moving mechanisms201are arranged opposite in the direction perpendicular to the sheet surface, thus the failure inspection apparatus is provided with four probe moving mechanisms201.

A probe203arranged in each of four probe moving mechanisms201is moved to the position of the evaluation element on the wafer217by the probe position controller223capable of being driven independently of the stage234. Movement is carried out with confirming in such a manner that an electron beam controller271scans around the evaluation element on the wafer217with an electron beam266, and that a secondary electron from the wafer217is detected by a secondary electron detector237to display an image of the element portion on an image display apparatus238.

In this embodiment, a power supply269is connected to each probe203so that voltage can be applied to a minute portion of the wafer217with which applied to a minute portion of the wafer217with which the probe203comes into contact. At the same time, an amperemeter270is also connected to each probe203so that a current flowing in each probe203can be measured. As an example of an evaluation method, a case in a MOS device formed on the wafer217is described. First, three probes203are brought into contact with a source electrode, a gate electrode and a drain electrode, respectively. The source electrode is grounded using the probe203, and while exciting voltage of the gate electrode as a parameter by the probe203, a relationship between a drain voltage and a drain current flowing between the source and a drain by the probe203. This provides an output property of the MOS. These operations are collectively controlled by the central processing unit240.

As the moving mechanism of each probe203, the probe moving mechanism201of the slant entering type shown inFIGS. 17 and 18is used, so that an inspection of the wafer217with a large diameter can be achieved with a compact apparatus. Further, since the structure of probe moving mechanism201is one that the replacement or the like of the probe203can be easily carried out, and therefore, an operating rate of the apparatus can be improved.

FIG. 27is a sectional view when a probe moving mechanism201of the present invention is figure, an FIB227emitted from the ion source225is focused on a desired position on the stage234by passing through an optical system226. The focused ion beam, that is, FIB227is spattered in the form of scanning the surface of the wafer217to carry out fine processing. On the stage234, the wafer217, semiconductor tip, or the like are placed, and the stage position controller235determines an observation position on the wafer217. The probe203mounted on the probe moving mechanism201is moved to the observation position on the wafer217by the probe position controller223which can drive independently of the stage234. Movement and processing are carried out while observing in such a manner that the FIB controller236scans around the observation position on the wafer217with the FIB, that a secondary electron from the wafer217is detected by a secondary electron detector237, and that an obtained secondary particle image is displayed on an image display apparatus238. A power supply269is connected to the probe203so that voltage can be applied to a minute portion of the wafer217with which the probe203is brought into contact. In observation, a groove is provided around a circuit by the FIB so as to electrically isolate the circuit to be observed from other circuits. The voltage applied probe203is brought into contact with an end of the circuit, and a position is observed which is considered to be connected to the circuit in design. is considered to be connected to the circuit in design. When connected without any break, a contrast is changed (brightened), so that failure of the circuit can be determined. These operations are collectively controlled by the central processing unit240. As the moving mechanism of the probe, the probe moving mechanism201of the slant entering type shown inFIGS. 17 and 18is used, so that an inspection of the wafer217with a large diameter can be achieved with a compact apparatus. Further, since the structure of probe moving mechanism201is one that the replacement or the like of the probe203can be easily carried out, and therefore, an operating rate of the apparatus can be improved.

The same effects as the present invention can be obtained in, for example, a sample creating apparatus using a projection ion beam which is structure by replacing a deflector230and an objective lens231with a mask plate and a projection lens, or a sample observing apparatus using a laser beam which is structured by replacing an ion source225with a laser source.