WO2001079810A1

WO2001079810A1 - Focused ion beam apparatus and piece sample pick-up method

Info

Publication number: WO2001079810A1
Application number: PCT/JP2001/003173
Authority: WO
Inventors: Toshiaki Fujii; Toshio Kodama
Original assignee: Seiko Instruments Inc.
Priority date: 2000-04-13
Filing date: 2001-04-12
Publication date: 2001-10-25
Also published as: TW494533B

Abstract

An apparatus and method for picking up a piece separated from a sample substrate by sputtering etching by use of a focused ion beam. Conventionally, as a method for picking up a piece separated from a sample substrate, the piece is fixed to a pickup before the piece is completely separated from the sample substrate, and the piece is separated from the sample substrate by performing the remaining processes. Therefore it is hard to automate the rough drilling for separating the piece from the sample substrate, and the entire working process cannot be made efficient. According to the invention, a sample is placed on a sample holder, pieces are separated from the sample by using a focused ion beam, the separated pieces are picked up one by one by a pickup, and they are transferred onto a piece holding section on the sample holder.

Description

Technical Field The present invention relates to a focused ion beam processing apparatus, which performs a bright sputter etching process on a sample surface such as a semiconductor integrated circuit or a ceramic substrate, and a small sample from the sample surface. The method relates to a method of separating a separated sample and removing a separated small sample. Background art

As an application of a focused ion beam device, there is a preparation of a sample piece for observation and analysis by a transmission electron microscope (abbreviated as TEM) using a fine precision sputter etching function.

The first conventional fabrication method is Microscopy of Semiconducting Material Conferenc e, Oxford, 1989, pp. 501-506. In this document, a chip with a length of several mm and a width of 100 to 500 ι is cut out using a dicing saw, attached to a standard mesh for TEM observation, and then focused. It is processed to a desired thickness by ion beam sputter etching.

In the first conventional manufacturing method, dicing is used to reduce the size of the sample, but due to mechanical processing, it can only be processed from a width of about 100 to 500 Aim. However, in order to perform observation and analysis by TEM, the width must be at least about 1μικι or less, and focus to that width. It must be processed by an ion beam. Therefore, it took a long time to prepare the sample. As a method for overcoming the drawback of the first conventional manufacturing method, there is a technique disclosed in Japanese Patent Application Laid-Open No. 5-52721. In the second conventional manufacturing method, as shown in Fig. 1, a focused ion beam 1 is irradiated from at least two different angles to sputter-etch around the TEM observation piece 3 including the observation target 2. Then, the needle 4 for picking up is brought into contact with the small piece 3 for TEM observation without separating from the sample by leaving the remaining portion 5. Then, a thin film is formed by a deposition function of the focused ion beam apparatus so that the needle 4 and the TEM observation small piece 3 are connected, and the needle 4 and the TEM observation small piece 3 are attached. Subsequently, the remaining portion 5 is subjected to sputter etching to separate the sample from the small piece 3 for TEM observation. As a result, the sputter etching process using the focused ion beam 1 to be performed to produce the small pieces 3 for TEM observation has been greatly shortened.

As the miniaturization of semiconductor integrated circuits has progressed, electron scanning microscopes have been used instead of conventional optical microscopes, and TEMs have been used for observing their structures. Therefore, the necessity of producing small pieces for TEM observation using a focused ion beam apparatus has become more and more necessary, and it has become necessary to produce many samples in a short time.

The production of small pieces for TEM observation using an actual focused ion beam system involves rough digging to separate the small pieces from the sample substrate, and finishing to make the small pieces even thinner so that a specified location can be observed by TEM. Can be roughly divided into Rough digging does not require much processing precision because it is sputter-etched at a location distant from the TEM observation site, but generally requires a long processing time because the volume removed by sputter-etching is large. On the other hand, the finishing time is shorter than that of rough digging because the volume of sputter etching is small. Therefore, rough digging, which does not require much processing precision, is performed by unmanned operation, such as at night, to devise ways to reduce the time required for human processing. In addition, with the improvement of the processing accuracy of the equipment, finishing processing has also been performed automatically.

However, according to the second conventional manufacturing method, the work for picking up the TEM observation piece without completely separating it from the sample substrate was performed, and then the processing for separation was performed. From the moment the pickups were glued, it was necessary to work with humans. For this reason, there was a disadvantage that the efficiency of the small piece production work did not increase.

Therefore, an object of the present invention is to provide an apparatus and a method for removing small pieces for TEM observation that have been subjected to predetermined processing and mechanically separated from a sample substrate. 'DISCLOSURE OF THE INVENTION In the present invention, as a first means, a sample chamber which is a vacuum vessel, a sample stage on which a sample substrate is placed and which can move at least in a horizontal direction and can be tilted, A focused ion beam column comprising an ion source for generating a beam, an ion beam optical system for focusing and deflecting and scanning the ion beam generated from the ion source, and focused ions generated from the focused ion beam column on a sample substrate Detects secondary charged particles generated when irradiating a beam. Using a focused ion beam processing device consisting of a detector and a detector that uses a focused ion beam to cut out small pieces from a sample using a sputtering ring etching function In the first step of determining the processing positions of a plurality of small pieces to be cut out from the sample, and sequentially sputtering the periphery of each of the small pieces to be cut out. A second step of performing a cutting process, and inclining the sample stage on which the sample is placed, and sequentially sputtering and etching the bottom of each of the small pieces to be cut out. And a third step of cutting out the plurality of small pieces to be cut out from the sample.

As a second means, a sample chamber which is a vacuum vessel, a sample stage on which a sample substrate is placed and which can move at least in a horizontal direction and can be tilted, an ion source for generating a light beam, and A focused ion beam column composed of an ion beam optical system for focusing and deflecting and scanning an ion beam generated from an ion source; and a sample substrate irradiated with a focused ion beam generated from the focused ion beam column. Using a detector that detects the secondary charged particles generated, and a focused ion beam device consisting of a pickup that picks up small pieces separated from the surface of the sample substrate by sputter etching of the focused ion beam In the method of removing small pieces from a sample by the etching function, the processing positions of multiple small pieces cut out from the sample are determined. A second step of sequentially 'sputtering' etching the periphery of each of the small pieces to be cut out, and inclining a sample stage on which the sample is placed, and setting a bottom of each of the small pieces to be cut out. A third step of sequentially sputtering and etching, and a fourth step of sequentially moving the sample stage to the pick-up tip position of each of the small pieces to be cut out and taking out the small pieces by the pickup, and We propose a small sample removal method, which is characterized in that it is removed from the sample.

As a third means, the sample chamber is mounted on a sample holder consisting of a vacuum chamber and a sample holder consisting of a sample holder and a holder for holding a plurality of small pieces taken out of the sample. A sample stage that can move and tilt in the direction, an ion source that generates an ion beam, and a focused ion beam column that includes an ion beam that focuses and deflects and scans the ion beam generated from the ion source. The secondary generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column Using a focused ion beam device consisting of a detector that detects charged particles and a sputter etching process of a focused ion beam from the surface of the sample substrate that picks up small pieces separated by using a focused ion beam, sputtering using a focused ion beam. In the method of extracting small pieces of the above, a first step of determining processing positions of a plurality of small pieces to be cut out of the sample, a second step of sequentially performing a sputtering process around each of the small pieces to be cut out, and an etching process, A third step of inclining the mounted sample stage and sequentially sputtering and etching the bottom of each of the small pieces to be cut out, and the tip end position of the pickup by operating one of the small pieces to be cut out by operating the sample stage. Ij, and take out one of the small pieces to be cut out by the pickup. A fourth step of moving the sample stage so that the small piece holder on the sample holder is at the position of the pickup; and a fifth step of moving the small piece picked up by the pickup to the sample. A sixth step of transferring the small piece from the sample to the small-piece holding section on the holder, wherein the small-piece sample removing method is characterized in that the small piece is transferred to the small-piece holding section on the sample holder. .

In the present invention, as a first mode of the apparatus, a sample chamber which is a vacuum vessel and a sample holder including a sample holding portion for holding a sample and a plurality of small pieces taken out from the sample are attached and mounted. A sample stage that can be placed and moved at least in a horizontal direction and can be tilted, a ion source that generates an ion beam, and an ion beam optical system that focuses, deflects and scans the ion beam generated from the ion source An ion beam column, a detector for detecting secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and a detector for detecting the focused ion beam from the surface of the sample substrate. In a focused ion beam apparatus comprising a pickup for picking up small pieces separated by sputter etching, The present invention proposes a focused ion beam processing apparatus characterized in that the tip of the cup is composed of two claws, and these claws move to pick up the small piece by sandwiching the small piece.

As the first form of the pickup tip of the first device, the pickup device is attached to a sample chamber, which is a vacuum chamber, and a sample holder including a sample holding portion and a holding portion for holding a plurality of small pieces extracted from the sample. A sample stage that can be mounted and at least horizontally moved and tilted, an ion source that generates an ion beam, and an ion beam optic that focuses and scans the ion beam generated from the ion source. A focused ion beam column made of a system, a detector for detecting secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and a focused ion from the surface of the sample substrate. In a focused ion beam apparatus including a pick-up for picking up small pieces separated by a beam sputtering process, The tip of the flop is composed of two claws, by sandwiching the piece is moving these claws proposes collecting beam ion beam processing apparatus characterized by taking up the pieces.

Further, as a first form of the pick-up tip claw, two of the pick-up tips are movable claws, one of which is a movable claw and is connected to the other fixed claw by a rotating shaft. The present invention proposes a mode in which the movable claw moves in a rotational direction about a rotation axis, and the movable claw is controlled by a piezoelectric actuator provided between the movable claw and the fixed claw.

As a second mode of the pick-up tip claw, the material is a shape memory alloy, and a heater for controlling the temperature of the shape memory alloy portion of the claw is provided, and the claw is opened and closed by the temperature control by the heater. Is proposed.

As a third form of the pick-up tip nail, the nail is made of a conductive material, and a power source is connected between the nail and the sample held in the test holder, An embodiment is proposed in which a current flowing when the nail and the sample come into contact is detected to avoid collision between the tip of the nail and the sample. Further, the first and second embodiments may be combined with the third embodiment.

In the present invention, as a second embodiment of the apparatus, a sample chamber, which is a vacuum vessel, and a sample holder comprising a sample holding section and a holding section ′ for holding a plurality of small pieces taken out of the sample, are mounted. A sample stage capable of moving and tilting at least in a horizontal direction; a source for generating an ion beam; and an ion beam optical system for converging and scanning the ion beam generated from the ion source. A focused ion beam column, a detector for detecting secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and a focused ion beam from the surface of the sample substrate. In a focused ion beam apparatus comprising a pickup for picking up small pieces separated by using a sputtering process, the tip of the pick-up Has a needle shape, and picks up the small piece by attaching the small piece to the tip of the needle-shaped pick-up.

As a first form of the pickup tip of the second device, a tip is proposed in which the tip is a needle made of an insulator, and the small piece is attracted and picked up by static electricity generated by charging the tip of the needle. .

At this time, as a first means for charging the tip, we propose a means for rubbing against another insulator to charge ^ 'As a second means for charging the tip, by irradiating a focused ion beam Means for charging the needle tip is proposed.

As a third means for charging the tip, an electron beam irradiation device is attached to the sample chamber, and the tip of the needle is charged by irradiating the tip of the needle with the electron beam of the electron beam irradiation device. Suggest means. According to the third embodiment of the present invention, as a third embodiment of the apparatus, a sample chamber, which is a vacuum vessel, and a sample holder, which is provided with a sample holding portion and a holding portion for holding a plurality of small pieces taken out of the sample, are mounted and placed. A sample stage that can move and tilt at least in a horizontal direction, an ion source that generates an ion beam, and a focused ion beam that includes an ion beam optical system that focuses and deflects and scans the ion beam generated from the ion source A column, a sample substrate, and a detector for irradiating the focused ion beam generated from the focused ion beam column with a secondary charged particle generated at the time of the irradiation; and a sputter beam of the focused ion beam from the sample substrate surface. A pick-up for picking up small pieces separated by using a chucking process, and a deposit on the sample surface at the same time as the focused ion beam irradiation in the sample chamber. A gas introduction device for depositing a conductive deposit in the focused ion beam irradiation area by spraying a gas serving as a raw material is attached, and the tip of the pickup is made of a needle made of a conductive material. A power supply is connected between the sample substrates, and the needle and the small piece separated from the sample substrate are brought into close contact with each other, and a conductive substance is deposited so as to connect the needle and the small piece. When the output current value of the power source exceeds a certain value, the deposition of the conductive substance is terminated, and the small piece is taken out by utilizing the fact that the needle and the small piece are connected. We propose a beam processing device. :

In addition, as the form of the pickup, the first operation of performing the fine movement in three dimensions with at least the set resolution ίϊΐ Αί ίϊΐ or less by operating the atmosphere at the tip of the pickup, and the first operation of removing the small piece. A mode is proposed in which a second operation of moving between the position and a second position that is out of the field of view for observation processing with a normal focused ion beam is possible.

Furthermore, in order to facilitate the operation of the pickup, when performing the operation of moving the tip of the pickup, the observation image by the focused ion beam irradiation is rotated. The present invention proposes a mode in which the direction of movement of the tip of the pickup coincides with the horizontal and vertical directions on the observation image.

In the present invention, as a fourth embodiment of the apparatus, a sample chamber, which is a vacuum vessel, and a sample holder, which includes a sample holding portion for holding a sample and a holding portion for holding a plurality of small pieces extracted from the sample, are mounted. A sample stage that can be placed and moved at least in the horizontal direction and can be tilted, an ion source that generates an ion beam, and an ion beam optical system that focuses, deflects, and scans the ion beam generated from the ion source. A focused ion beam column, a detector for detecting secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and a focused ion beam from the surface of the sample substrate. In a focused ion beam system consisting of a pickup that picks up small pieces separated by using a spa A sample transporter for taking out a sample held in a sample container, placing the sample on the sample holder 13 of the sample holder placed outside the sample chamber, and being attached to the sample chamber. A load lock chamber having a gate valve for opening and closing between the atmosphere side door and the vacuum chamber; and transferring the sample holder from outside the sample chamber to the sample stage of the sample chamber through the load lock chamber. Holding the sample holder transporter, taking out the sample held in the sample container by the sample transporter, placing the sample holder in the sample holder of the sample holder placed outside the sample chamber, The sample holder holding the sample is transported to the load lock chamber at atmospheric pressure by the sample holder transporter, and the air lock side door of the load lock chamber is closed. The load lock chamber is evacuated, the degree of vacuum in the □ '-drop chamber is made substantially equal to the degree of vacuum in the sample chamber, the gate valve is opened, and the sample placed in the load lock chamber is opened. The holder is transferred to the sample stage in the sample chamber by the sample holder transporter, and One or a plurality of small pieces are cut out from the sample by irradiating a bundle ion beam, the small pieces are picked up by the pickup, transferred to the small piece holder on the sample holder, and the sample holder is transferred to the sample holder transporter. Moving the sample holder into the mouth lock chamber, closing the gate valve, opening the load lock chamber to the atmosphere, opening the atmosphere side door, and moving the sample holder by the sample holder transporter. A focused ion beam application method, wherein the sample held in the sample holder on the sample holder by the sample transporter is transferred to the sample container. A device is proposed. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows an example of processing in the second conventional manufacturing method.

Figure 2 shows the focused ion beam column and control power supply.

FIG. 3 is a conceptual diagram relating to the tilt axis of the sample stage used in the focused ion beam device of the present invention.

FIG. 4 shows a conceptual diagram of the 'pickup' used in the present invention.

FIG. 5 shows a processing example in the present invention.

FIG. 6 shows an embodiment of the pickup.

FIG. 7 shows an embodiment in addition to the pickup.

FIG. 8 is an explanatory view of the moving direction of the tip of the pickup.

FIG. 9 shows an embodiment of the sample holder.

FIG. 10 shows a configuration example of the device according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 2 shows an example of a focused ion beam column used in the present invention.

Focused ion beam column mainly consists of ion source section 11 and condenser lens 1 2, consisting of a blanking electrode 13, a movable diaphragm 14, a deflection electrode 15, and an objective lens 16. In addition, although not shown, there are an optical axis correction electrode and an astigmatism correction electrode.

As the ion source 11, a liquid metal gallium is generally used. The liquid metal gallium stored in the reservoir is supplied to the needle-shaped emitter by surface tension. In addition, reservoirs and emitters can be overheated by filaments. An electric field is applied to the emitter section by one or more electrodes, and gallium stored in the emitter section is extracted as an ion beam. The emitter is accelerated by this electric field because a high voltage of about +30 kV is applied to the ground potential.

The ion beam is focused by the condenser lens 12 and focused on the sample surface by the objective lens 16. FIG. 2 shows an Einzel's-type lens in which a low voltage and a ground potential are connected to three electrodes, but this is only an example, and other evening lenses may be used. Although the objective lens 16 is arranged at the position closest to the sample, the position can be changed according to the required performance and function.

The movable aperture 14 has a plurality of through-holes having different diameters. The aperture control section controls the position of the through-hole, and the used through-hole is switched. By passing the ion beam through each through hole, the amount of the ion beam reaching the sample, that is, the sample current can be changed. In addition, the position of the through hole can be adjusted so that the position matches the center of the ion beam.

The blanking electrode 13 can generate a large electric field between the two electrodes. When the same potential, usually ground potential, is applied to each electrode, the ion beam reaches the sample. However, when a large electric field is generated by applying a signal with a large potential difference to each of the blanking electrodes 13, The on-beam is largely deflected, hits a shield such as a movable diaphragm, and the ion beam does not reach the sample.

• The deflecting electrode 15 is composed of at least two pairs of electrodes facing each other, and the trajectory of the ion beam is two-dimensionally controlled by the electric field generated between the electrodes.

The ion source, each electrode, and the movable diaphragm are controlled by an ion source control power supply 18, a capacitor lens control power supply 19, a blanking signal and scanning signal generator 20, an objective lens control power supply 22, and a movable diaphragm control power supply 21. . Each control power supply is controlled by a computer 17 '. Further, signals applied to the blanking electrode and the deflection electrode are generated from the scanning signal generator 20. This makes it possible to determine whether or not to irradiate the sample with the ion beam according to the sample irradiation position. Although not shown, the output signal of the detector is input to the scanning signal generator 20 and processed. Observation of the sample surface by detecting the ion beam irradiation position and secondary charged particles generated by ion beam irradiation at the irradiation position with a detector and storing the output signal as an electric signal together Can be.

Figure 3 shows a conceptual diagram of the sample stage of the proposed device. The sample stage 31 is movable in at least two axes, horizontal X and Y, and can tilt the sample surface. Further, it may be movable in the vertical Z-axis. At this time, the mechanism for tilting is under the function of driving the horizontal and vertical axes. Therefore, when the sample is tilted, the X and Y axes move parallel to the inclined plane, and Z moves in the normal direction to the inclined plane.

The detector detects secondary charged particles (electrons or ions) generated by irradiating the sample with the focused ion beam.

Although the gas introduction device is not shown in detail, a container for storing gas or gas raw material, a nozzle for blowing gas onto the sample surface, and a connection between the container and nozzle The gas is the raw material for the deposition film formation by the beam assisted CVD method. The sample is used in the beam assisted CVD method. Generally, it is a molecular gas containing the material of the thin film deposited on the surface The gas blown to the sample surface is adsorbed on the sample surface In this state, when the focused beam is irradiated, At this time, the molecular gas is decomposed by the kinetic energy, and the decomposed gas components are exhausted to the outside of the sample chamber by the vacuum pump, and the solid components remain as a thin film on the sample surface. At the same time, the sputter etching is performed, so that the deposition rate of the thin film is higher than the sputter etching rate. Cormorants, it is necessary to control the introduction amount of the raw material gas, the irradiation amount of the focused ion beam.

It is to be noted that a plurality of gas introduction devices may be used, or a gas introduction device a having pipes and valves corresponding to a plurality of gas storage containers may be used so that gases can be properly used according to purposes.

The sample chamber and the focused ion beam column are evacuated by a vacuum pump. Although not shown, the sample chamber may be provided with a load lock chamber for taking the sample in and out of the chamber without rubbing.

FIG. 4 shows the basic configuration of the pickup of the present invention. The tip 41 of the pickup has three axes: an X axis 42 for moving the tip left and right, a Y axis 43 for moving the tip back and forth, and a Z axis 44 for moving the tip up and down. Stage 45. This stage 45 is located in a vacuum chamber, and its control is performed by an actuator or knob located on the atmospheric side (not shown). The case 46 on which this stage 45 is installed is attached to the sample chamber of the focused ion beam device, but the distance between the case 46 and the sample chamber can be changed by the bellows structure 47. In addition, an operating position for picking up the small pieces for TEM observation and a retracting position for escaping from the irradiation area of the focused ion beam can be switched by a pickup or a pneumatic device (not shown). The rod 48 connecting the pickup and the stage for moving the peak is supported by the pod support 49 of the case 46, ensuring position repeatability when returning from the retracted position to the operating position. F) and so on. The case 46 and the sample chamber are connected through a large hole so that the vacuum evacuation in the case 46 can be performed without interruption. Fix the pickup tip 41 to the tip of the load 48 with the fixing part 50. When the pickup tip 41 is made of a conductive material, an insulating material is used for the fixing part 50 to electrically separate the pickup tip 41. In addition, since the fixing portion 50 has a very fine shape at the tip portion 41 of the pickup, it can be easily replaced. The conductive pickup tip 41 is electrically connected to a sample 53 via a power source 51 and a current source 52. When the tip 41 of the pickup contacts the surface of the sample 53, a current flows. By detecting the current with the current detector 52, the contact between the pickup end 41 and the sample 53 can be confirmed.

Figure 5 shows an example of rough digging by focused ion beam and sputter etching to separate a small piece for TEM observation from a sample substrate. In the example shown in Fig. 5, the cross section of the sample substrate is to be observed by TEM. For this reason, all sides are subjected to a sputtering etching process so as to surround a desired sectional observation region. Finally, the sample stage is tilted, and a sputter etching process is performed to separate the small pieces for TEM observation from the sample substrate obliquely. '

This rough digging process has a large processing volume to be sputter-etched. Therefore, unmanned driving is performed at night or on holidays. In unmanned operation, the processing frame is determined so as to leave the desired TEM observation area, and a mark whose position relative to the processing frame is clear is determined. At this time, if there is no appropriate mark, It is manufactured by the processing function of the focused ion beam device. As a result, the position of the mark and the relative position of the mark and the processing frame are stored. When preparing a plurality of small pieces for TEM observation, perform the same pretreatment for each. Then, unmanned automatic processing starts. The sample stage first moves to the mark position, and confirms the mark position by the pattern recognition function. Subsequently, a processing frame whose position relative to the mark position is clear is arranged, and processing is performed according to a predetermined order. The process of separating the sample substrate and the small piece for TEM observation is the last step of manufacturing each small piece for TEM observation, but may be performed for each small piece, or only the processing for separation may be left at the end . If left at the end, the specimen for TEM observation remains with only the processing to be separated. In this state, processing to tilt and separate the sample stage is performed. In this case, since the sample stage can be tilted only once, the time required for processing can be reduced.

Next, the pick-up tips and how to pick up small pieces using them are explained.

The first embodiment has a tweezer structure shown in FIG. The tip of the pickup has two parts, a fixed part 61 and a movable part 62. The fixing part 61 has a structure connected to the pickup body. The movable part 62 is connected to the fixed part 61 via a rotating shaft 63. The movable part 62 is controlled by an actuator 64. By controlling the actuator 64, a small sample can be inserted. Although not shown, the fixing portion 61 is made of a conductive material, and the fixing portion 61 is connected to a power source different from the power source of the actuator 64. The other end of this power supply is connected to the sample

When picking up a small TEM observation piece separated from the sample substrate by the method shown in Fig. 5, tilt the sample stage so that the surface of the sample substrate 53 is perpendicular to the tweezers nail. Let it. Next, the sample stage is Move the tweezers claw and the TEM observation piece closer by moving them in the surface normal direction. Subsequently, the sample stage is moved in the normal direction of the sample substrate so that the nail enters the portion etched by the sputter to remove the TEM observation small piece from the sample substrate 53. The sample stage is stopped when the nail moves to a position where the small piece for TEM observation can be sandwiched. Subsequently, the actuator 64 is controlled to close the nail, and a small piece for TEM observation is sandwiched. Subsequently, the TEM observation small piece can be picked up by moving the sample stage in the normal direction of the sample surface and away from the end 41 of the pick-up tip.

These operations can be performed while observing by using the observation function of the focused ion beam.

Further, as described above, the surface of the sample substrate 53 is brought into contact with the tip portion 41 of the pickup at the mark processing position. At this time, collision between the sample substrate 53 and the pickup distal end portion 41 is avoided by detecting a current flowing when the sample substrate 53 and the pickup distal end portion 41 are electrically connected to each other. Then, by re-confirming the three-dimensional position of the pickup distal end portion 41, it is possible to more reliably pick up the small sample for TEM observation. In addition, it can be performed automatically without using a focused ion beam observation function.

In the second embodiment, a needle made of an insulating material is used at the tip of the pickup. First, bring the needle close to the small piece for TEM observation separated from the sample substrate. In this state, a focused ion beam is applied to the needle made of an insulating material to cause a chuck. The small pieces for TEM observation have high resistance because they are separated from the sample substrate, and are attracted to the needle by electrostatic force.

At this time, as in the first embodiment, the sample stage is perpendicular to the needle or tilted at an angle suitable for operation. With the tip of the pickup and the TEM sample piece in contact, move the sample stage in the direction normal to this inclined surface. The sample is taken up. Actually, the position of the TEM sample piece does not change and the sample substrate side is separated.

In the third embodiment, a needle made of a conductive material is used at the tip of the pickup. First, bring the needle close to the small piece for TEM observation separated from the sample substrate. In this state, a conductive film is formed so as to connect the needle and the small piece for TEM observation. At this time, both ends of one power supply are connected to the needle and the sample surface. By forming a conductive film, the load resistance of the power supply is reduced, and the output current is increased. When the current value exceeds a certain value, it indicates that the cross-sectional area of the formed conductive film is sufficient to support a small piece for TEM observation. Therefore, the deposition is terminated. At this time, the power supply may be DC or AC, but the optimum conditions are determined in consideration of the impedance between the sample substrate, the TEM observation piece, and the tip of the pickup. If the DC resistance is large, use an AC signal to handle it.

In the fourth embodiment, as shown in FIG. 7, the tip of the pickup has a pin set portion 65 made of a shape memory alloy and a heater 66 for changing the temperature of the tweezer portion 65 and a temperature setting of the heater 66. Row Control power supply 67. In the example of FIG. 7A, the pin set section 65 is closed because the control power supply 67 'is in the stopped state. As shown in FIG. 7 (b), when the control power supply 67 is in a movable state, the tweezers 65 is set to a predetermined temperature by the heater 66 and is opened. The method of moving the sample stage for picking up the TEM observation sample is the same as in the first and second embodiments.

The operation of moving the tip of the pick-up will be described with reference to FIG. Generally, the horizontal movement XY axis of the sample 72 is arranged along the vertical and horizontal directions of the observation image. Therefore, can the movement of the sample 72 be intuitively recognized in the observation image? ing. On the other hand, the horizontal movement XY axis of the pickup tip 71 is different in angle from the horizontal movement axis of the sample 72. So, Pickup Tip 7 When performing the operation for determining the position 1, the observation image is rotated, and the length and width of the observation image are aligned with the horizontal movement axis of the pick-up tip 71. By doing so, the operator can intuitively move the pick-up tip position while watching the observation image.

FIG. 9 shows an example of a sample holder used in the present invention. The sample holder 81 includes a sample holding section 83 for holding a sample 82 and a small piece holding section 85 for holding a plurality of small pieces 84. In this embodiment, the bottom surface of the sample holder 81 is flat like a semiconductor wafer. In a sample transfer device for semiconductor wafers, a wafer handler, etc., the handler can be provided with an adsorption function such as an electrostatic chuck so that it can be automatically transferred. In the focusing beam device, the sample is held on the sample holder and placed on the sample stage, or the wafer set in the wafer cassette is taken out and transported by an e-handler or the like, and transported to the sample stage. It is common to place them on The sample holder shown in Fig. 9 can be handled with a wafer handler for semiconductor wafers by setting it in a dedicated cassette.

The sample holding unit 83 is a TEM / sample holder for fixing a TEM sample. As a holding method, an adhesive is prepared in advance on the holding surface. In addition, a deposition film using a focused ion beam is held as a substitute for the adhesive.

Further, FIG. 10 shows a configuration of a focused ion beam apparatus using the sample holder 81 shown in FIG. Place the cassette 92 on which the wafer 90 is set in the cassette holder 91 of the equipment. The wafer 90 is taken out from the wafer cassette 92 by the wafer handler 93 and set in the sample holder 83 of the sample holder 81 placed on the atmosphere side.を The sample holder 81 set in the wafer 90 is moved to the low pressure Transfer to lock room 95. 'Open the door 96 on the atmosphere side of the lock chamber 95 and evacuate it by the evacuation system (not shown). When the degree of vacuum in the load lock chamber 95 reaches a predetermined pressure, the gate valve 97 between the load lock chamber 95 and the sample chamber 98 is opened. The sample holder 81 is set on the sample stage 99 by the sample transport system 94, and the gate valve 97 is closed. Subsequently, the small piece 84 is taken out from the wafer 90 by the above-described method and transferred to the small piece holding portion 85 on the sample holder 81. After the work is completed, the gate valve 97 is opened again, the sample holder 81 is moved to the load lock chamber 95 by the sample transfer system 94, and the gate valve 97 is closed. After the load lock 95 is opened to the atmosphere, the air side door 96 is opened, and the sample holder 81 is taken out of the lock chamber by the sample transfer system 94. The wafer 90 set in the sample holder 83 of the sample holder 81 is picked up by the handler 18 and returned to the cassette 92. Subsequently, the small piece transferred to the small piece holding portion 85 on the sample holder 81 is observed and analyzed by an observation-analyzer such as a TEM (1).

As described above, by using the apparatus and the method according to the present invention, it is possible to sequentially take out a plurality of pieces for TEM observation which have been subjected to observation processing and fence processing from a sample in advance. Since the rough digging after deposition for picking up, which is a disadvantage of the conventional method, is eliminated, the ratio of unmanned machining during the process can be increased.

Further, according to the first, second, and fourth embodiments of the present invention, it is possible to avoid another problem in the second conventional manufacturing method, that is, the problem of consumption of the pickup. In the second conventional manufacturing method, a small piece is taken out using a deposition as in the third embodiment of the present invention, but the tip of the needle is sputter-etched to separate it. Therefore, there was a problem that the tip of the needle was worn. However, according to the methods of the first, second and fourth embodiments of the present invention, there is an effect that this problem can be avoided. Industrial applicability

As described above, by using the apparatus and the method according to the present invention, it is possible to provide an apparatus and a method for completing a predetermined process and mechanically picking up a TEM observation piece already separated from a sample substrate. .

Claims

The scope of the claims

1. A sample chamber, which is a vacuum vessel, a sample stage on which a sample substrate is placed and which can be moved at least horizontally and tilted, an ion source for generating an ion beam, and an ion beam generated from the ion source A focused ion beam column made up of an ion beam optical system that focuses and polarizes the ion beam, and secondary charging generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column. In a method of using a focused ion beam processing device consisting of a detector for detecting particles and a method of cutting out a piece from a sample by a sputtering method using a focused ion beam, the roe positions of a plurality of small pieces cut out from the sample are determined. The first step of determining, and the second step of sequentially performing sputtering and etching around the small pieces to be cut out,

■ A sample stage on which the sample is placed is tilted, and the bottom of each of the small pieces to be cut out is sequentially sputtered. ■ A third step of etching is performed, and the plurality of small pieces to be cut out are separated from the sample. Characteristic small piece Sample cutting method.

2. A sample chamber which is a vacuum container, a sample stage on which a sample substrate is placed and which can be moved at least horizontally and tilted, and an ion beam source for generating an ion beam, and A focused ion beam column composed of an ion beam optical system that focuses the generated ion beam and performs deflection scanning, and secondary charging generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column. Using a focused ion beam system consisting of a detector that detects particles and a pickup that picks up small pieces separated from the sample substrate surface by sputter etching of the focused ion beam, the sample is provided by a focused ion beam and a spur ring and etching function. Small from In the method of taking out pieces,

A first step of determining processing positions of a plurality of small pieces to be cut out from the sample; a second step of sequentially performing sputtering and etching around each of the small pieces to be cut out;

A third step of tilting the sample stage on which the sample is mounted, and sequentially sputtering and etching the bottom of each of the small pieces to be cut out;

A fourth step of sequentially moving the sample stage to the pick-up tip position of each of the small pieces to be cut out and removing the small pieces by the pickup, and removing the small pieces from the sample. Method.

3. Attach and mount the sample chamber, which is a vacuum chamber, and a sample holder consisting of a sample holding section and a holding section for holding a plurality of small pieces taken out of the sample, and move at least horizontally to tilt A focused ion beam column comprising an ion source for generating an ion beam, and an ion beam optical system for focusing and deflecting and scanning the ion beam generated from the ion source; A detector that detects secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and is separated from the surface of the sample substrate by sputter etching of the focused ion beam. Using a focused ion beam device consisting of a pickup that picks up the small pieces, sputtering using a focused ion beam A method of taking out a small piece from,

A first step of determining a processing position of a plurality of small pieces cut out from the sample, a second step of sequentially sputtering and etching the periphery of each small piece to be cut out,

A third step of tilting the sample stage on which the sample is placed, and sequentially etching the bottom of each of the small pieces to be cut out; A fourth step of moving one of the small pieces to be cut out to the tip position of the pickup by operating the sample stage, and taking out one of the small pieces to be cut out by the pick up;

A fifth step of moving the sample stage so that the small piece holding portion on the sample holder is at the position of the pickup;

A sixth step of transferring the small piece picked up by the pickup to the small piece holding portion on the sample holder;

And removing the small piece from the sample and transferring the small piece to the small piece holding part on the sample holder.

4. Attach and place the sample chamber, which is a vacuum container, and a sample holder consisting of a sample holder and a holder for holding a plurality of small pieces taken out of the sample, and move at least horizontally. A sample stage that can be tilted; a focused ion beam mirror comprising an ion source for generating an ion beam; and an ion beam optical system for focusing and deflecting and scanning the ion beam generated from the source. A tube, a detector for detecting secondary charged particles generated when the sample substrate is irradiated with a focused ion beam generated from the focused ion beam column, and a sputter etching process of the focused ion beam from the surface of the sample substrate. In a focusing device consisting of a pickup for picking up small pieces separated by using

A focused ion beam processing apparatus, wherein the tip of the pickup comprises two claws, and the claws move to sandwich the small piece, thereby picking up the small piece.

5. The two claws at the tip of the pickup according to claim 4, one of which is a movable claw, is connected to the other fixed claw by a rotating shaft, and the movable claw is centered on the rotating shaft. A focusing means for moving in a rotational direction, wherein the movable claw is controlled by a piezoelectric actuator disposed between the fixed claw and the movable claw. On-beam processing equipment.

6-The pick-up tip according to claim 4, wherein the two hooks are made of a shape memory alloy, and have a heater for controlling the temperature of the shape memory alloy portion of the hook, and the heater controls the temperature. Wherein the claw is opened and closed by a press.

7. The focused ion beam processing apparatus according to claim 4, wherein the claw is made of a conductive material, and a power source is connected between the claw and the sample held in the sample holder; A focused ion beam processing apparatus, wherein a current flowing when the sample comes into contact is detected to avoid collision between the tip of the nail and the sample.

8. Attach and place the sample chamber, which is a vacuum container, and a sample holder consisting of a sample holding part and a holding part for holding a plurality of small pieces taken out of the sample, and move at least horizontally. A focused ion beam column comprising a sample stage capable of tilting, an ion source for generating ions and beams, and an ion beam optical system for focusing and deflecting and scanning the ion beam generated from the ion source. And a detector for detecting secondary charged particles generated when the sample substrate is irradiated with the focused ion beam generated from the focused ion beam column, and using sputter etching and processing of the focused ion beam from the surface of the sample substrate. Focusing device consisting of a pickup that picks up small pieces separated by

A focused ion beam processing apparatus, wherein the pick-up has a needle-like tip, and picks up the small piece by attaching the small piece to the needle-like pickup tip.

9. The focused ion beam processing apparatus according to claim 8, wherein the tip of the pickup is a needle made of an insulator, and the small piece is attracted and picked up by static electricity generated by charging the tip of the needle. Focused on Beam processing equipment.

10. The focused ion beam processing apparatus according to claim 8, wherein the tip of the needle is rubbed against another insulator to be charged.

11. The focused ion beam processing apparatus according to claim 8, wherein the tip of the needle is charged by irradiating a focused ion beam to the tip of the needle.

12. The focused ion beam processing apparatus according to claim 8, wherein an electron beam irradiator is attached to the sample chamber, and the tip of the needle is irradiated with an electron beam of the electron beam irradiator. Focused ion beam processing equipment characterized by charging the needle tip.

13. The focused ion beam processing apparatus according to claim 8, wherein a gas serving as a raw material for deposits is sprayed on the surface of the sample simultaneously with the irradiation of the focused ion beam into the sample chamber, whereby conductive deposition is performed in the focused ion beam irradiation region. A gas introduction device for depositing an object is attached, the tip of the pickup is made of a needle made of a conductive material, and a power source is connected between the needle and the sample substrate. The separated small piece is placed very close to the position, a conductive substance is deposited so as to connect the needle and the small piece, and when the output current value of the power supply exceeds a certain value, the conductive substance is deposited. The focused ion beam processing apparatus is characterized in that the small piece is taken out by utilizing the fact that the needle and the small piece are connected.

14. The pickup device according to claim 4, wherein the tip device performs a three-dimensional fine movement of at least a set resolution of 1 m or less by an operation on the atmosphere side, and an operation for removing small pieces. Characterized by being capable of performing a second operation of moving between a first position for performing observation and a second position that is out of the field of view for observation and processing by a normal focused ion beam. Beam processing equipment.

15. The focused ion beam processing apparatus according to claim 4, wherein, when performing the operation of moving the tip of the pick-up, an observation image by the irradiation of the focused ion beam is rotated, and a moving direction of the tip of the pickup is the observation image. A focused ion beam processing apparatus characterized in that the horizontal and vertical directions coincide with each other.

16. Mounted on a sample chamber, which is a vacuum container, and a sample holder consisting of a sample holder and a holder for holding a plurality of small pieces taken out of the sample, and moved at least horizontally. A sample stage that can be tilted, a focused ion beam column including an ion source that generates an ion beam, and an ion beam optical system that focuses and deflects and scans the ion beam generated from the ion source; A detector that detects secondary charged particles generated when the sample substrate is irradiated with a focused ion beam generated from the focused ion beam column, and is separated from the surface of the sample substrate by sputter etching of the focused ion beam. In an on-beam device consisting of a pickup that picks up small pieces,

A sample container for holding a sample, a sample carrier taken out of the sample container, and a sample carrier mounted on the sample holder of the sample holder placed outside the sample chamber; and A load lock chamber attached to the sample chamber and having a gate valve that opens and closes between the atmosphere side door and the vacuum chamber; and the sample holder is connected to the sample chamber through the load lock chamber from outside the sample chamber. Holding the sample holder transporter for transferring to the sample stage, removing the sample held in the sample container by the sample transporter, and removing the sample from the sample holder placed outside the sample chamber; The sample holder, which is placed on a holding unit and holds the sample, is transported to the load lock chamber at atmospheric pressure by the sample holder transporter, and the sample holder is transported. -I

5 27

Ib =

Close the atmosphere side door of the lock chamber, evacuate the load lock chamber, evacuate the chamber, make the degree of vacuum in the load lock chamber approximately equal to the degree of vacuum in the sample chamber, open the gate valve, and lock the gate lock. The sample holder installed in the sample chamber is moved onto the sample stage in the sample chamber by the sample holder transporter.

5

One or a plurality of small pieces are cut out from the sample by irradiating the focused ion beam, the small pieces are picked up by the pickup, and transferred to the small piece holder on the sample holder,

The sample holder is connected to the port by the sample holder transporter.

10 Move to a load lock chamber, close the gate valve, open the load lock chamber to the atmosphere, open the atmosphere side door, and take the sample holder out of the sample chamber by the sample holder transporter. Transferring the sample held in the sample holder on the sample holder by the sample transporter to the sample container

Focused ion beam processing equipment <

Figure 1

(b) Sample tilted

(c) 4

(d) Pickup status