JP2020034323A - Protective film manufacturing apparatus - Google Patents

Abstract

An object of the present invention is to provide a protective film manufacturing apparatus capable of manufacturing a protective film without causing damage to a small area targeted by a sample.
A protective film manufacturing apparatus includes a sample stage (12) on which a sample (10) as an object for forming a protective film is set, and an observation mechanism (optical microscope (14)) for observing the surface of the sample (10) supported on the sample stage (12). A monitor 17), an adjustment mechanism for adjusting the relative position between the sample stage 12 and the optical microscope 14, a probe 20 accommodating a protective material to be supplied to the sample 10 supported by the sample stage 12, and supporting the probe 20. A robot arm 16 for positioning an injection port at the tip of the probe 20 at a required position of the sample 10, and injection mechanisms 22 and 24 connected to the probe 20 and injecting the protective material supplied to the probe 20.
[Selection diagram] Fig. 1

Description

  The present invention relates to an apparatus for producing a protective film used for producing a sample of an FIB apparatus and the like.

  In order to observe a fine internal structure of a material, a sample is cut using an FIB, and a cross section is observed using an SEM. When cutting with FIB, the spread of the ion beam not only damages the target but also the area around it. Therefore, in FIB processing for cross-sectional observation, a method is used in which a protective film is formed before processing and cut from above the protective film to prevent the observed cross section from being damaged by an ion beam. .

  As a method for forming a protective film, there is a method of forming a thin film of carbon or metal on a material surface by vapor deposition or sputtering (Non-Patent Document 1). In addition, there is a method of manufacturing a protective film using a deposition gun mounted on an FIB device (Patent Document 1). In this method, the compound gas is decomposed by irradiating an ion beam while spraying a compound gas, which is a raw material of a protective film, onto the sample surface using a deposition gun, thereby decomposing the compound gas and attaching the decomposed solid component to the sample surface. This is a method for forming a protective film.

Japanese Patent Application Laid-Open No. 2000-147681

FIB / Ion Milling Technique Q & A 2002 P54 Masao Itabe Takehiko Watanabe

In the above-mentioned method of forming a thin film of carbon or metal on the material surface by vapor deposition or sputtering, damage due to heat generated during vapor deposition occurs, and it is difficult to control the place where the thin film is formed. It is difficult to make a film. On the other hand, in the method of forming a protective film using a deposition gun, it is possible to form a thin film of carbon, tungsten, platinum, or the like in a target minute region. Since the beam is directly irradiated, the surface layer of the sample may be damaged, or a long time may be required depending on manufacturing conditions.
In addition, in the method of applying the conductive paste to the sample surface, a protective film can be formed in a short time and at low cost. However, the range in which the protective film is applied may be too large, and a minute region may be formed. Not suitable if you want to aim. Further, the sample surface may be physically touched during the application, and when a thin film or the like is formed on the sample surface, the state of the thin film may be broken.
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique for forming a protective film without causing damage to a target minute region of a material.

The protective film manufacturing apparatus according to the present invention includes a sample stage for setting a sample which is an object for forming a protective film, an observation mechanism for observing a surface of the sample set on the sample stage, the sample stage and the observation. An adjustment mechanism for adjusting a relative position with respect to the mechanism, a probe accommodating a protective material to be supplied to the sample supported on the sample stage, supporting the probe, and projecting a tip of the probe to a required position of the sample. A robot arm for positioning an outlet, and an injection mechanism connected to the probe and injecting a protective material supplied to the probe are provided.
The protective film manufacturing apparatus according to the present invention can form a protective film on a minute region of a sample surface by injecting a protective material as a material of the protective film from a fine probe as a method of applying the protective film. . The application of the protective film is performed by increasing the internal pressure of the probe filled with the protective material and injecting the protective material.

Further, the injection mechanism may include a tube having one end connected to a base end side of the probe, and a blower connected to the other end side of the tube to increase an internal pressure of the probe and inject a protective material from the probe. Thus, the protection member can be easily and accurately injected using the injection mechanism having a simple configuration.
Further, the observation mechanism is provided with an optical microscope for visually recognizing the sample and a monitor for displaying an optical microscope image, thereby enabling to accurately detect a part where the protective material is to be injected and to inject the protective material, By observing with an optical microscope, color information on the sample surface can be obtained in the same way as when viewed with the naked eye, and the protective material can be accurately ejected to the required position while observing the color change of a small area on the sample surface. It becomes possible to do.
Further, the adjusting mechanism includes a drive mechanism for moving the sample stage in the x-axis, y-axis, and z-axis directions and a personal computer that controls the drive mechanism, so that the position at which the protective material of the sample is injected can be accurately determined. And it can be easily positioned.
In addition, the robot arm includes a moving mechanism for moving in the x-axis, y-axis, and z-axis directions, and a personal computer that controls the moving mechanism, thereby accurately positioning a position for injecting the protective material onto the sample. Can be.
In addition, by using a hollow glass probe having a tip diameter of several μm to 1 mm as the probe, a protective material can be easily injected to form a protective film. Paste carbon obtained by dissolving carbon in water can be used effectively.

  ADVANTAGE OF THE INVENTION According to this invention, when producing a protective film etc. by FIB processing, a protective film can be produced only in the target micro area without touching the sample surface. Therefore, even for a sample with a structure in which the sample surface is deformed by heat or physical contact, a protective film can be produced without damaging the surface. In the observation, a cross section of the sample with less damage can be observed.

It is the schematic which shows the structural example of a protective film manufacturing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The protective film manufacturing apparatus according to the present invention operates the robot arm 16 equipped with a protective material injection mechanism while observing with the optical microscope 14 as shown in FIG. Thus, a protective film is formed.

(Form of device)
FIG. 1 is a schematic configuration diagram of a micromanipulator system which is an embodiment of a device for forming a protective film on a minute region used in the present invention. This micromanipulator system has a sample stage 12 on which a sample 10 to be formed of a protective film is placed, and an optical microscope 14 and a monitor 17 as an observation mechanism of the placed sample 10, and a robot arm 16. By providing these mechanisms, the robot arm 16 can be moved by a computer operation while observing an image of the sample 10 observed by the optical microscope 14 on the monitor 17.

  The sample stage 12 has a mechanism for rotating in addition to moving back and forth, up and down and left and right. The robot arm 16 has a mechanism for changing the angle of the arm in addition to the movement in the front, rear, up, down, left and right directions. In addition, the robot arm 16 has a mechanism capable of attaching various types by selecting a jig 20 to be attached to the arm. In the present apparatus, the jig 20 to which the probe 18 can be attached is attached. An elastic tube 22 is attached to the probe 18 attached to the robot arm 16, and a blower 24 necessary for pressurizing the opposite side of the side on which the probe 18 is attached is attached. The method for pressurizing may not be a method in which the tube 22 and the blower 24 are mounted, but may be any method that can increase the internal pressure of the probe 18. Further, the optical microscope 14 and the robot arm 16 are not integrated as in the micromanipulator system, but may be separated from each other.

(Preparation of probe)
A glass tube is used for producing the probe 18 used in this method. Using a device called a puller, the glass tube is stretched by applying heat to the center of the side surface of the glass tube while pulling the glass tube at both ends, and finally cut to produce a probe 18 having a thin tip. The tip of the probe 18 produced by the puller is further adjusted to have an arbitrary tip diameter using a cutting instrument or the like. By adjusting the tip diameter of the probe 18, the size of the finally formed protective film can be adjusted. As the probe diameter increases, the protective material is injected over a wide range, and as the probe diameter decreases, the protective material is injected into a smaller area.

(Selection of protective material)
The protective material used as the raw material of the protective film used in the present method needs to be capable of filling the probe 18 having a micrometer-sized tip at the tip from a technical point of view, and capable of being injected by some method after filling. Any material that is conductive and soluble in a solvent such as water or an organic solvent can be used as a raw material for a protective film.

(Procedure for preparing protective film)
As a procedure for forming a protective film, first, the sample 10 is set on the sample stage 12 of the micromanipulator, and the probe mounting jig 20 is mounted on the robot arm 16.
Next, while observing the optical microscope image, the focus is set on the region of the surface of the sample 10 where the protective film is to be formed.
Next, the tube 22 to which the blower 24 is attached is attached to the probe 18. Thereafter, the probe 18 is filled with a protective material, and the probe 18 is mounted on a jig 20 attached to the robot arm 16.

While observing with the optical microscope 14, the robot arm 16 to which the probe 18 is attached is operated to move the tip of the probe 18 to a place where a protective film is to be formed. At this time, the robot arm 16 is moved back and forth, up and down and left and right to bring the probe 18 close to the surface of the sample 10 so as not to touch the sample 10.
By pushing the blower 24 to increase the internal pressure in the probe 18, the protective material is ejected from the probe 18. After the injection, the probe 18 is separated from the sample 10. The solvent of the protective material is vaporized, and a protective film having a diameter of several hundred micrometers is formed on the surface of the sample 10. By changing the injection amount of the protective material, the size and thickness of the formed film can be adjusted.

Hereinafter, an example in which a protective film is actually formed on a minute region on the surface of the sample 10 will be described.
In the present embodiment, an example is shown in which a protective film is formed on a marking portion of Sample 10 in which marking of several hundred microns is performed on a silicon base material.

A micromanipulator system having an optical microscope 14 and a robot arm 16 having the configuration shown in FIG. 1 was used. The micromanipulator system can be enlarged and observed by the optical microscope 14, and the sample stage 12 and the robot arm 16 can be driven in front, rear, up, down, left, and right directions.
As the protective material, a carbon paste obtained by diluting conductive carbon with water so as to have a mass concentration of 2.5 times was used.
Further, a probe made of glass was used as the probe 18 for applying the carbon paste. A glass tube was prepared by processing it using a puller and a cutting instrument, and the one having a tip diameter of about 100 μm was used. As a tube 22 connected to the probe 18, a silicon tube having an inner diameter of 1 mm was used, and a rubber-made manual blower was used to increase the internal pressure in the probe 18.

First, the sample 10 was placed on the sample stage 12, and the sample stage 12 was moved to focus on a target location on the surface of the sample 10.
Next, the probe 18 was attached to the tube 22, and a rubber blower 24 was attached to the opposite side.
Next, a carbon paste was prepared and filled in the probe 18.
Next, a jig 20 for attaching a probe was attached to the robot arm 16 of the micromanipulator system, and the probe 18 was attached to the jig 20.
Next, the tip of the probe 18 was moved to a target position on the surface of the sample 10 by a computer operation while checking on a monitor. At this time, the tip of the probe 18 was brought close enough to not touch the surface of the sample 10.

After that, the internal pressure in the probe 18 was increased by pushing the blower 24 to inject the garbon paste. The solvent of the injected carbon paste was vaporized after several minutes, and a protective film was formed.
Observation of the formed protective film with an optical microscope 14 confirmed that the protective film had a shape close to a circle having a diameter of about 100 μm, and was formed at a target marking portion.

Next, cutting with an ion beam was performed on the produced protective film, and a cross section was observed. In this embodiment, for the cutting of the ion beam and the observation of the cross section, a combined beam processing and observation apparatus (product name: JIB-4610F, manufactured by JEOL Ltd.) in which a focused ion beam processing apparatus and a scanning electron microscope were integrated was used. .
First, processing was performed by irradiating a gallium ion beam from a vertical direction to a portion where the protective film was applied.
Next, the processed cross section was observed by performing observation with an electron beam from the cross section direction. As a result of observation from the cross-sectional direction, no damage due to the ion beam was observed.

Reference Signs List 10 sample 12 sample stage 14 optical microscope 16 robot arm 17 monitor 18 probe 20 jig 22 tube 24 blower

Claims (7)

A sample stage for setting a sample which is an object for forming a protective film,
An observation mechanism for observing the surface of the sample set on the sample stage,
An adjustment mechanism for adjusting a relative position between the sample stage and the observation mechanism,
A probe in which a protective material to be supplied to the sample supported by the sample stage is housed,
A robot arm that supports the probe and positions an injection port at the tip of the probe at a required position of the sample;
An injection mechanism that is connected to the probe and that injects the protective material supplied to the probe.   The injection mechanism includes a tube having one end connected to a base end side of the probe, and a blower connected to the other end side of the tube, which increases an internal pressure of the probe and injects a protective material from the probe. The protective film manufacturing apparatus according to claim 1, wherein:   The protective film manufacturing apparatus according to claim 1, wherein the observation mechanism includes an optical microscope that visually recognizes the sample, and a monitor that displays an optical microscope image.   The said adjustment mechanism is provided with the drive mechanism which moves the said sample stage in an x-axis, a y-axis, and a z-axis direction, and the personal computer which controls this drive mechanism, The Claims any one of Claims 1-3 characterized by the above-mentioned. Protective film production equipment.   The protective film according to any one of claims 1 to 4, wherein the robot arm includes a moving mechanism for moving in the x-axis, y-axis, and z-axis directions, and a personal computer that controls the moving mechanism. Production equipment   The protective film manufacturing apparatus according to any one of claims 1 to 5, wherein the probe is a hollow glass probe having a tip diameter of several μm to 1 mm. The said protective material is the paste-like carbon which melt | dissolved the conductive carbon with water, The protective film manufacturing apparatus as described in any one of Claims 1-6 characterized by the above-mentioned.

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