JP3401158B2 - Ultra-high vacuum surface observation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention observes an atomic image of a sample by detecting a tunnel current flowing between a probe and the sample by utilizing the principle of tunnel effect, and at the same time an electron beam is applied to the sample. It belongs to the technical field of an ultra-high vacuum surface observation apparatus that observes a secondary electron image of a sample by detecting secondary electrons generated when an image is formed.

[0002]

2. Description of the Related Art The principle of the so-called tunnel effect, in which electrons move through a vacuum gap between a probe and a sample when a metal probe with a sharpened tip is brought close to the sample and a small bias voltage is applied between them, The scanning tunneling electron microscope (STM) used heretofore has been developed. This STM
Is equipped with an excellent surface observation technology that has atomic and molecular resolution on the sample surface, and allows the probe or sample to be two-dimensionally scanned using a piezoelectric element while keeping the distance between the probe and sample constant. This makes it possible to obtain an uneven image of the sample surface at the atomic level. And recently, this ST
It has an epoch-making method such as M having a function of scanning each atom.

FIG. 9 is a diagram schematically showing an example of such a conventional STM. In the figure, 1 is an STM, 2 is a probe made of tungsten or the like, 3 is a sample, 4 is a minute movement of the probe 2 in the Z-axis direction, a Z driver made of a piezoelectric element, and 5 is the XY-axis of the probe 2. An XY driver made of a piezoelectric element for two-dimensionally scanning in the direction, 6 is a Z moving mechanism for moving the probe 2 largely in the Z axis direction, 7 is a driving power source for driving the Z moving mechanism 6, and 8 is A scanning power source for driving the XY driver 5, a control power source 9 for driving the Z driver 4, 10 a tunnel current detector for detecting a tunnel current flowing between the probe 2 and the sample 3, 11 Is a voltage application power source for applying a voltage between the probe 2 and the sample 3, 12 is an amplifier for amplifying the tunnel current detected by the tunnel current detector 10, and 13 is each piezoelectric element of each driver 4, 5. An image display device that displays changes in the element voltage as a two-dimensional image is there.

In this STM 1, the probe 2 is moved to 1 nm with respect to the sample 3 by the Z moving mechanism 6 and the Z driver 4.
Get closer to the degree. Then, when a positive or negative voltage of several V or less is applied between the probe 2 and the sample 3 by the voltage applying power source 11, a tunnel current flows between the probe 2 and the sample 3. In this state, the probe 2 is two-dimensionally scanned by the XY driver 5, the tunnel current during the scanning is sequentially detected by the tunnel current detector 10, and the detected tunnel current is amplified by the amplifier 12. Send to the control power supply 9.
The control power supply 9 drives and controls the Z driver 4 to move the probe 2 up and down so that the tunnel current becomes constant. The change in the voltage of the piezoelectric element of the XY driver 5 and the change in the voltage of the piezoelectric element of the Z driver 4 at this time are displayed as a two-dimensional image by the image display device 13. In this way, an uneven image of the surface of the sample 3 can be obtained as an atomic level image. It is also possible to perform two-dimensional scanning with the height of the probe 2 kept constant, and display the change in tunnel current at that time as a two-dimensional image.

By the way, in the STM 1 as described above, since the distance between the probe 2 and the sample 3 is set and held at a very short distance of about 1 nm as described above, it is not possible to observe the flat sample 3. Although suitable, in the case of the sample 3 having a sharp surface irregularity, the probe 2 and the sample 3 may collide with each other and the probe 2 and the sample 3 may be damaged. For this reason, the STM1 is not suitable for observing the sample 3 having a large surface irregularity.

Further, when observing the unknown sample 3 or the sample 3 over a wide range, it is not clear whether the sample surface is rough or not. Therefore, the collision between the probe 2 and the sample 3 as described above is avoided. Therefore, the scanning speed of the probe 2 must be made very slow. For this reason, it takes a lot of time to perform the observation in such a case.

Therefore, it is conceivable to combine another surface observation device with the STM to make it possible to observe a sample that is difficult to observe with this STM. Conventionally, as a combination of the STM and another surface observation device, for example, Japanese Patent Laid-Open No. 4-1
There is one disclosed in Japanese Patent No. 28602. The surface observation device disclosed in this publication is a combination of an STM and a scanning electron microscope (SEM), and a probe position control mechanism allows the probe of the STM to be on the optical axis of the SEM. By controlling the advancing / retreating in the plane orthogonal to the optical axis, the observation by the STM and the observation by the SEM can be performed.

Another example of a combination of STM and SEM is disclosed in Japanese Patent Application Laid-Open No. 1-217248. In the surface observation device disclosed in this publication, the field emission needle of SEM and the metal probe of STM are shared by the same chip.
By controlling the position in the Z direction (height direction) between the observation position by M and the observation position by STM, the observation by STM and the observation by SEM can be performed.

[0009]

However, in the surface observation apparatus disclosed in Japanese Patent Application Laid-Open No. 4-128602, when the STM observation is performed, the STM probe is placed on the optical axis in a plane orthogonal to the optical axis of the SEM. Not only is it difficult to position the probe, but it also takes a lot of time to position it. Moreover, since the probe position control mechanism is required, not only the structure becomes complicated, but also the device becomes large. In particular, the structure of the probe is further complicated because it is necessary to control the position in the height direction with respect to the sample.

Further, in the surface observing apparatus disclosed in Japanese Patent Laid-Open No. 1-217248, a chip is placed at an observing position by SEM and ST
Since it has to largely move in the Z direction with respect to the observation position by M, it takes a lot of time to align the chip. Moreover, since the chip can be moved in the Z direction, not only is it necessarily lengthened in the Z direction, but also the Z moving mechanism for controlling the movement of the chip in the Z direction becomes large.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to observe an atomic image of a flat sample and to observe a sample having large irregularities over a wide range and in a short time. An object of the present invention is to provide an ultra-high vacuum surface observation apparatus that can be performed in a short time and can be formed compactly.

[0012]

In order to solve the above-mentioned problems, the invention of claim 1 provides an ultrahigh vacuum chamber in which an ultrahigh vacuum is held, and an electron beam or an electron beam provided in the ultrahigh vacuum chamber. An emitter for emitting an ion beam toward a sample, and a first electrode which is provided between the emitter and the sample in the ultra-high vacuum chamber and is an extraction electrode for extracting the electron beam or the ion beam from the emitter. A second electrode which is an acceleration electrode and which is positioned closest to the sample as an electrode for imaging the electron beam or the ion beam on the sample; and a sample facing side of the second electrode or the second electrode. A micro probe provided on a cover located between the sample, a Z moving mechanism for moving the micro probe toward or away from the sample, and XY scanning of the sample XY drive for adjusting the distance between the microprobe and the sample, a voltage application power supply for applying a voltage between the microprobe and the sample, It is characterized by comprising a detector for detecting a current flowing between the probe and the sample, and a secondary electron detector for detecting secondary electrons emitted from the sample.

Further, the invention of claim 2 is characterized in that the focal length of the electrostatic lens constituted by the electrodes can be adjusted. Further, the invention of claim 3 is characterized by comprising a deflector for changing and controlling the radiation direction of the electron beam or the ion beam with respect to the sample. Further, the invention of claim 4 is characterized in that an inert gas supply device for supplying an inert gas such as argon gas is provided in the ultra-high vacuum chamber.

According to a fifth aspect of the present invention, the emitter, the electrode, and the XYZ driver are provided in a support cylinder provided in the ultra-high vacuum chamber, and the support cylinder has the Z-shape.
It is characterized in that the fine probe is moved toward or away from the sample by being moved by a moving mechanism.

Further, the invention of claim 6 is characterized in that the secondary electron detector is provided such that its detection end is located in the support cylinder. Further, the invention of claim 7 is characterized in that the support cylinder and a sample stage for supporting the sample including the XY driver and the Z driver are integrally formed.

Further, the invention of claim 8 is an ultrahigh vacuum chamber in which an ultrahigh vacuum is maintained, and an emitter provided in the ultrahigh vacuum chamber for emitting an electron beam or an ion beam toward a sample. An electrode which is provided between the emitter and the sample in the ultra-high vacuum chamber and is an extraction electrode for extracting the electron beam or the ion beam from the emitter, and the electron beam or the ion beam to the sample. A magnetic field lens located closest to the sample as a lens for imaging, a microprobe provided on the magnetic field lens facing the sample, and a microprobe for approaching or separating the microprobe from the sample Z movement mechanism, XY driver for XY scanning of the sample, Z driver for adjusting the interval between the microprobe and the sample, and the microprobe A voltage applying power source for applying a voltage between said sample, a detector for detecting a current flowing between the sample and the fine tip, 2 emitted from the sample
A secondary electron detector for detecting secondary electrons is provided.

Further, the invention of claim 9 is a detection mode by a detector for detecting a current flowing between the microprobe and the sample, and a secondary electron detection for detecting secondary electrons emitted from the sample. The detection mode by the vessel is set,
It is characterized in that a switch for switching and setting both of these detection modes is provided.

[0018]

In the ultrahigh vacuum surface observing apparatus according to each of the first to eighth aspects of the present invention having such a structure, the STM for observing a sample at an atomic level by combining the STM microprobe and the SEM emitter. In addition to the observation, the SEM observation for observing with the secondary electron image comes to be performed by rapidly scanning the sample with large irregularities or the unknown sample which cannot be observed by the STM in a wide range.

Moreover, the STM microprobe and the SEM emitter are both aligned only in the Z direction, and the STM microprobe and SEM are aligned.
The amount of movement of the emitter is almost the same as in the case of the conventional STM alone and the conventional SEM alone, and is not so large. Therefore, the device does not become long in the Z direction, and the Z movement mechanism for controlling the movement of the STM microprobe and the SEM emitter in the Z direction becomes small. As a result, the surface observation device becomes compact.

Further, since the microprobe is provided on the side of the electrode or the magnetic field lens facing the sample, the distance between the sample and the electrode or the magnetic field lens can be accurately controlled, and the working distance can be controlled in micron order. Become. This makes it possible to narrow the electron beam more narrowly.

Since the structure of the emitter, which is a focused electron gun, is simple, the degree of vacuum is less likely to drop as compared with the usual focused electron gun. In particular, in the invention of claim 2, since the focal length of the electrostatic lens can be adjusted, the distance between the electrode and the sample can be freely adjusted. Further, in the invention of claim 3, since the emission direction of the electron beam or the ion beam with respect to the sample can be changed and controlled, the XY scanning of the sample can be performed without moving the sample.

In particular, in the invention of claim 4, the focused ion beam can be emitted from the emitter by introducing an inert gas such as argon gas into the ultrahigh vacuum chamber. This enables fine processing of the sample.
Also, secondary electron image observation by ion excitation is possible.

Further, in the invention of claim 5, the support cylinder allows the emitter, the XYZ driver, the electrode, and the microprobe to be more compactly assembled. This simplifies their handling.

Further, in the invention of claim 6, even when the secondary electron image is observed with the microprobe extremely close to the sample, the secondary electron detector more effectively detects the secondary electrons. It comes to detect. Further, in the invention of claim 7, since the support cylinder and the sample stage are formed as an integrated body, the size is reduced. This allows the ultra-high vacuum surface observation device to be compactly assembled.

Further, in the invention of claim 8, the electron beam is controlled by the magnetic field lens. Further, according to the invention of claim 9, by the switch setting,
The setting can be easily switched between the STM mode and the SEM mode.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a first example of an embodiment of an ultrahigh vacuum surface observation apparatus according to the present invention. The same components as those of the conventional STM described above are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, in the ultra-high vacuum surface observing apparatus 14 of the first example, the Z driving unit 4 and the XY driving unit 5 are both arranged on the sample 3 side, and the Z moving mechanism 6 is also provided. Are arranged on the side of the microprobe 2.

A support cylinder 15 is fixed to the lower surface of the Z moving mechanism 6, and an XYZ driver 16 is provided in the support cylinder 15.
Is attached. A heating filament 18 is fixed in the support cylinder 15 on the lower surface of the XYZ driver 16 via an emitter fixing insulator 17, and a field emission type emitter 19 is attached to the heating filament 18. There is. The field emission emitter 19 is heated by the heating filament 18. Further, inside the lower end opening of the support cylinder 15, there is a hole 21a in the center through the electrode fixing ceramic 20 and a first electrode 21 for extracting electrons from the emitter 19, and a hole 22a in the center. The second electrode 22 for acceleration is provided at a predetermined interval in the vertical direction. In that case, the height adjustment and the axial direction adjustment of the emitter 19 and the first electrode 21 are performed by the XYZ driver 16. Further, a fine probe 2 ′ is attached to the lower surface of the second electrode 22. These microprobe 2 ', sample 3,
The Z driver 4, the XY driver 5, the Z moving mechanism 6, and the support cylinder 15 are all arranged in the ultrahigh vacuum chamber 23.

Outside the ultra-high vacuum chamber 23, a drive power source 7 for driving the Z moving mechanism 6, a scanning power source 8 for driving the XY driver 5, and a Z driver 4 are driven. Control power source 9, tunnel current detector 10 for detecting a tunnel current flowing between microprobe 2'and sample 3, and power supply for applying voltage between microprobe 2'and sample 3 11, an amplifier 12 that amplifies the tunnel current detected by the tunnel current detector 10, an image display device 13 that displays a change in voltage of each piezoelectric element of each of the drivers 4 and 5 as a two-dimensional image, an XYZ driver 13 Control power supply 24 for driving the heating filament 18, heating power supply 25 for heating and driving the heating filament 18, drawing power supply 26 connected to the heating power supply 25 for driving the first electrode 21, and heating power supply 25. Connected to , And an acceleration power supply 27 for driving the second electrode 22 is provided.

The second electrode 22, that is, the microprobe 2 ′, is selectively electrically connected to either one of the voltage applying power source 11 and the acceleration power source 27 by the first switch 28. The sample 3 is selectively electrically connected to either the tunnel current detector 10 or the acceleration power source 27 by the second switch 29. These first and second switches 28 and 29 are both switches for mode switching between the STM mode and the secondary electron image observation mode (SEM mode), and are respectively set to the positions shown in the STM mode. Two
In the next electron image observation mode, the position is set to the position opposite to the illustrated position.

Further, in the ultrahigh vacuum chamber 23, a secondary electron detector 30 for detecting secondary electrons emitted from the sample 3 when the sample 3 is irradiated with an electron beam is arranged. The secondary electron detector 30 is connected to the image display device 13 via an amplifier 31.

In the ultrahigh vacuum surface observing apparatus 14 of the first example constructed as described above, when used as an STM, first the first and second switches 28 and 29 are set to the STM mode shown in FIG. Is set to. That is, the power source 1
1 is connected to the second electrode 22 to which the microprobe 2 ′ is attached and cut off from the acceleration power supply 27, and the detector 10 is connected to the sample 3 and cut off from the acceleration power supply 27. Then, the Z-moving mechanism 6 causes the microprobe 2'to approach the sample 3, and the Z driver 4 causes the sample 3 to approach the microprobe 2 ', so that the microprobe 2'and the sample 3 are about 1 nm. Approach each other. After that, when a positive or negative voltage of several V or less is applied between the microprobe 2 ′ and the sample 3 by the voltage applying power source 11, the microprobe 2 ′ and the sample 3
A tunnel current flows between and. In this state, the sample 3 is two-dimensionally scanned by the XY driver 5, the tunnel current during the scanning is sequentially detected by the tunnel current detector 10, and the detected tunnel current is amplified and controlled by the amplifier 12. Send to power supply 9. The control power source 9 is the Z driver 4
Is controlled to move the sample 3 up and down so that the tunnel current becomes constant. The change in the voltage of the piezoelectric element of the XY driver 5 and the change in the voltage of the piezoelectric element of the Z driver 4 at this time are displayed as a two-dimensional image by the image display device 13. In this way, the unevenness image of the surface of the sample 3 can be obtained as an atomic level image.

When used as a secondary electron image observation, that is, as a scanning electron microscope (hereinafter also referred to as SEM), the first and second switches 28 and 29 are the SEM on the side opposite to the side shown in FIG. Set to mode. That is,
The power supply 11 is connected to the acceleration power supply 27 and the second electrode 22
The detector 10 is connected to the acceleration power supply 27 and is disconnected from the sample 3 as well. And, if it is set for STM observation, from this STM observation state,
The Z-moving mechanism 6 moves the microprobe 2 ′ from the sample 3 to several μm.
~ Move a few mm away. At this time, if the length of the micro probe 2'is as short as several μm, this distance can be regarded as the working distance of the focusing probe gun. The heating power supply 25 drives the heating filament 18 to heat the emitter 19, and the extraction power supply 26 applies a negative voltage to the first electrode 21 and the acceleration power supply 27 applies a negative voltage to the second electrode 22. . As a result, the electron beam is emitted from the emitter 19. Then, the emitter 19 and the first electrode 2 are driven by the XYZ driver 16 driven and controlled by the control power supply 24.
1 and the position of the first and second electrodes 21,
Emission from the emitter 19 as shown in FIG. 2 by changing the voltage value of 22 or changing the distance between the sample 3 and the second electrode 22 by the Z moving mechanism 6 driven and controlled by the driving power supply 7. The sampled electron beam 32
Focus on top. In that case, when the polar radius of the microprobe 2 ′ is 100 nm or less, the electrode hole diameter is about 5 to 10 μm, and the distance between the emitter 19 and the first electrode 21 is about 10 to 30 μm, the voltage of the first electrode is With a voltage of −100 to −200 V and a voltage of the second electrode of −1 kV or less, it is possible to form an image under the second electrode 22 to several tens of μm or less, and a beam diameter of several ones.
It can be 0 nm or less. Of course, the distance between the electrodes is m
It is also possible to set the voltage in units of m and the voltage in units of several kV.

As a result, the secondary electrons e are emitted from the sample 3. After that, XY drive-controlled by the scanning power supply 8
The sample 3 is two-dimensionally scanned by the driver 5, the secondary electrons e emitted from the sample 3 are detected by the secondary electron detector 30, and the secondary electrons detected by the secondary electron detector 30 are detected. Is amplified by the amplifier 31 and displayed on the image display device 13, and a secondary electron image, that is, a SEM image is observed. Further, it is possible to detect the current flowing in the sample 3 and image it as in the case of the STM.

As described above, according to the ultrahigh vacuum surface observing apparatus of the first example, STM observation of the sample 3 and observation of the secondary electron image by the focused electron beam are possible. Therefore, not only can the STM observation of the flat sample 3 be performed at the atomic level, but also the observation of the sample 3 having large irregularities and the observation of the unknown sample 3 can be easily and quickly performed by SEM observation. Become. Moreover, since the positioning of the microprobe 2'and the emitter 19 in the Z direction can be performed individually, the movement amount in the Z direction can be small and can be performed easily in a short time.

In addition, the microprobe 2'and the emitter 1
Since the amount of movement of 9 in the Z direction is small, the ultra-high vacuum surface observation device 14 can be shortened in the Z direction, and the Z movement mechanism 6 for controlling the movement of the microprobe 2 ′ and the emitter 19 in the Z direction is small. Ultra high vacuum surface observation device 14
Can be formed compactly.

Since the microprobe 2'is provided on the sample facing side of the second electrode 22, the distance between the sample 3 and the second electrode 22 can be accurately controlled, and the working distance can be controlled in the order of microns. become. As a result, the electron beam 3
2 can be narrowed down more.

Further, the diameter of each of the holes 21a and 22a of the first and second electrodes 21 and 22 is about several μm to 100 μm in order to suppress the voltage applied to these electrodes to 1 kV or less. By providing the microprobe 2 ′ in the vicinity of the hole 22a of the electrode 22, the deviation between the visual field for the sample 3 in the STM observation and the visual field for the sample 3 in the secondary electron image observation is also 10 μm or less. Can be suppressed. Therefore, the ultra-high vacuum surface observation apparatus 14 of the first example is
Simultaneous observation is not possible in M observation and SEM observation, but the same visual field can be observed to some extent. In addition, the above-mentioned first
In the example, the microprobe 2 ′ is provided separately from the second electrode 22, but it may be formed integrally with the second electrode 22 by etching or the like.

By the way, in the ultrahigh vacuum surface observing apparatus 14 of the first example, the voltage between the emitter 19 and the first electrode 21 is constant and cannot be changed. Therefore, if the number of electrodes is two, the voltage of the second electrode 22 is also determined, and as a result, the distance between the second electrode 22 and the sample 3 located at the imaging point of the electron beam 32 cannot be changed. . That is, the first
Also, the focal length of the lens composed of the second electrodes 21 and 22 cannot be changed.

Therefore, it is desirable that the distance between the second electrode 22 and the sample 3 located at the image forming point of the electron beam 32 can be freely changed. FIG. 3 shows a second example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention, in which the distance between the second electrode 22 and the sample 3 located at the image forming point of the electron beam 32 can be freely set. It is a figure which partially shows the example which can be changed. Note that FIG.
The same components as those of the ultra-high vacuum surface observation apparatus of the first example are assigned the same reference numerals and detailed description thereof will be omitted.

In the above-mentioned first example, two electrodes, that is, the first electrode 21 and the second electrode 22 are provided, but in the ultra-high vacuum surface observation apparatus 14 of this second example, it is shown in FIG. As described above, the third electrode 33 having the hole 33a in the center is provided between the first electrode 21 and the second electrode 22, and the lens power source 34 is provided between the third electrode 33 and the sample 3.
Is provided. The other configuration of the ultra-high vacuum surface observation device 14 of the second example is the same as that of the first example of FIG. In addition,
Although most of the other components such as the secondary electron detector 30, the first and second switches 28 and 29 are not shown in FIG. 3, the configuration of those parts not shown is as shown in FIG. It goes without saying that they are the same.

In the ultra-high vacuum surface observing apparatus 14 of the example shown in FIG. 3 configured as above, the voltage of the third electrode 33 is changed by the lens power source 34 so that the second electrode 22 and the image forming point are positioned. It becomes possible to freely change the distance to a certain sample 3. That is, the first to third electrodes 2
It becomes possible to freely change the focal length of the lens composed of 1, 22, 30. Further, other operational effects of the ultra-high vacuum surface observation device 14 of this second example are the same as those of the first example.

FIG. 4 is a view partially showing a third example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention. The same components as those of the ultra-high vacuum surface observation apparatus of the first example in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In contrast to the first example shown in FIG. 1, the ultrahigh vacuum surface observing apparatus 14 of the third example is arranged in the ultrahigh vacuum chamber 23 through a valve 35 as shown in FIG. A gas cylinder 36 storing an inert gas such as is connected. Further, in the above-mentioned first example, the ultra-high vacuum chamber 23 is simply kept in the ultra-high vacuum, but the ultra-high vacuum surface observation apparatus 1 of this example 1
In No. 4, by opening and closing the valve 35, the inert gas is introduced from the gas cylinder 36 into the ultra-high vacuum chamber 23. Ultra-high vacuum surface observation apparatus 1 of this third example
Other configurations of No. 4 are the same as those of the first example shown in FIG. Although most of the other components such as the secondary electron detector 30, the first and second switches 28 and 29 are not shown in FIG. 4, the configuration of those parts not shown is It goes without saying that it is the same as 1.

In the ultrahigh-vacuum surface observing apparatus 14 of the third example configured as described above, an inert gas is introduced into the ultrahigh-vacuum chamber 23, and the first and second electrodes 2 are also introduced.
A focused ion beam can be generated from the emitter 19 by applying a voltage having a polarity opposite to that of the electron beam 32 described above to the electrodes 1 and 22, respectively. That is, the emitter 19, the first and second electrodes 2
1,22 can be used as a focused ion beam source.
As a result, according to the ultra-high vacuum surface observing apparatus 14 of the third example, it becomes possible to perform fine processing such as etching of the sample 3. In addition, the ultra-high vacuum surface observation device 14 of the third example
Other functions and effects of are the same as those of the first example.

FIG. 5 is a view partially showing a fourth example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention. The same components as those of the ultra-high vacuum surface observation apparatus of the first example in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the above-mentioned first example, the secondary electron detector 30 is arranged inside the ultra-high vacuum chamber 23 outside the support cylinder 15, but in the ultra-high vacuum surface observation apparatus 14 of this fourth example. ,
As shown in FIG. 5, the secondary electron detector 30 is connected to the detection end 3
0a is provided in the support cylinder 15 such that it is positioned inside the support cylinder 15. The other configuration of the ultrahigh vacuum surface observation device 14 of the fourth example is the same as that of the first example of FIG.

In the ultrahigh vacuum surface observing apparatus 14 of the fourth example configured as described above, the microprobe 2'is set to the sample 3
When a secondary electron image is to be observed with the electron beam 32 from the emitter 19 impinging on the sample 3, most of the secondary electrons e generated from the sample 3 are in the support tube 15. Since it enters the secondary electron detector 30, the secondary electron detector 30 effectively detects the secondary electron e. Further, other operational effects of the ultra-high vacuum surface observation device 14 of the fourth example are the same as those of the first example.

FIG. 6 is a view partially showing a fifth example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention. The same components as those of the ultra-high vacuum surface observation apparatus of the first example in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

Ultra-high vacuum surface observation device 14 of each of the above-mentioned examples
Both use an electrostatic lens composed of two or three electrodes, but the ultra-high vacuum surface observation apparatus 1 of this fifth example is used.
4, as shown in FIG. 6, the second electrode 2 of the first example of FIG.
A magnetic lens 37 is provided instead of 2, and
Magnetic field lens power supply 3 for driving and controlling this magnetic field lens 37
8 are provided. Then, the electron beam 32 emitted from the emitter 19 is imaged on the sample 3 by the magnetic field lens 37. Further, the magnetic field lens 37 is provided with a fine probe 2 ′ for STM. The other configuration of the ultrahigh vacuum surface observation device 14 of the fifth example is the same as that of the first example of FIG. In FIG. 6, the secondary electron detector 30, the first
Although most of the other constituent elements such as the second switch 28 and 29 are not described, it goes without saying that the configuration of the parts not described is the same as that of FIG. 1.
The operation and effect of the ultrahigh vacuum surface observation device 14 of the fifth example is also the same as that of the first example.

FIG. 7 is a view partially showing a sixth example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention. The same components as those of the ultra-high vacuum surface observation apparatus of the first example in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

Although none of the ultra-high vacuum surface observation apparatus 14 of the first to fourth examples described above is provided below the second electrode 22, the ultra-high vacuum surface observation apparatus of the sixth example is not provided. In the device 14, as shown in FIG. 7, a cylindrical electrostatic deflector 39 is provided below the second electrode 22 of the first example of FIG. 1, and the electrostatic deflector 39 is drive-controlled. An electrostatic deflector power supply 40 is provided. Further, a cover 41 is provided below the electrostatic deflector 39, and the STM microprobe 2 ′ is provided on the cover 41.

Then, the electrostatic deflector 39 deflects and scans the electron beam 32 in the XY plane.
It becomes possible to perform two-dimensional scanning of the sample 3. Therefore, even if the XY driver 5 is not used, the S
It becomes possible to perform EM observation.

The other structure of the ultrahigh vacuum surface observing apparatus 14 of the sixth example is the same as that of the first example of FIG. In FIG. 7, the secondary electron detector 30, the first and second switches 28,
Although most of the other components such as 29 are not described,
Needless to say, the configurations of these not-described parts are the same as those in FIG.

The other operational effects of the ultrahigh vacuum surface observation device 14 of the sixth example are also the same as those of the first example.

FIG. 8 is a view partially showing a seventh example of the embodiment of the ultra-high vacuum surface observation apparatus of the present invention. The same components as those of the ultra-high vacuum surface observation apparatus of the first example in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In each of the above-described ultra-high vacuum surface observing apparatuses 14 of the first to sixth examples, the supporting cylinder 15 and the sample stage on which the sample 3 including the Z driver 4 and the XY driver 5 is mounted are separately provided. However, in the ultra-high vacuum surface observation apparatus 14 of the seventh example, the support cylinder 15 and the sample stage 42 are integrally supported as shown in FIG. That is, the first base 44 fixed to the ultra high vacuum flange 43.
In addition, an L-shaped second base 46 is supported via the stack vibration isolation mechanism 45, and a slide mechanism 47 constituting the Z moving mechanism 6 is provided on the horizontal side of the second base 46 in the Z direction (in FIG. 8). It is supported slidably in the left-right direction.

The support cylinder 15 is fixed to the slide mechanism 47 so that the axial direction of the support cylinder 15 is aligned with the left-right direction. On the other hand, on the vertical side of the second base 46, the sample stage 42 including the Z driver 4 and the XY driver 5 on which the sample 3 is mounted is fixed. The other configuration of the ultrahigh vacuum surface observation device 14 of the seventh example is the same as the first example of FIG. Although most of the other components such as the secondary electron detector 30 and the first and second switches 28 and 29 are not shown in FIG. 8, the configuration of those parts not shown is It goes without saying that it is the same as 1.

In the ultrahigh vacuum surface observing apparatus 14 of the seventh example configured as described above, the sample stage and the support cylinder 15 are provided.
And are connected and integrated by the second base 46 and the slide mechanism 47. With this integration, SE
Ultra-high vacuum surface observing device 1 because M structure part is small
4 can be compactly put together.

Moreover, since the small integrated body of the sample stage and the support cylinder 15 can be put into the ultrahigh vacuum as it is, the ultrahigh vacuum surface observing apparatus 14 of the seventh example also reduces gas emission, It is very suitable for ultra-high vacuum observation.

Furthermore, since a small integrated body of the sample stage and the support cylinder 15 is supported by the first base 44 via the stack vibration isolation mechanism 45, it is possible to prevent external vibration and to achieve atomic resolution of STM. Can be observed more accurately.

In each of the above examples, only the secondary electron detector is provided, but the sample can also be analyzed by attaching an energy analyzer in addition to the secondary electron detector.

[0063]

As is apparent from the above description, according to the ultra-high vacuum surface observation apparatus of the present invention, STM observation for observing a sample at the atomic level can be performed, and ST
SEM observation for observing with a secondary electron image can be performed by quickly and quickly scanning a sample with large irregularities or an unknown sample that cannot be observed with M over a wide range. Moreover, alignment of the microprobe and the emitter in the Z direction can be performed easily in a short time because a small amount of movement in the Z direction is required.

In addition, the surface observation device can be shortened in the Z direction, and the Z movement mechanism for controlling the movement of the microprobe and the emitter in the Z direction can be downsized, so that the surface observation device can be made compact.

Further, since the microprobe is provided on the side of the electrode or the magnetic field lens facing the sample, the distance between the sample and the electrode or the magnetic lens can be accurately controlled, and the working distance can be controlled in the order of microns. Thereby, the electron beam or the ion beam can be narrowed down more.
Since the structure of the emitter, which is a focused electron gun, is simple, it is possible to reduce the degree of vacuum reduction as compared with a normal focused electron gun.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a first example of an embodiment of an ultra-high vacuum surface observation device according to the present invention.

FIG. 2 is a diagram illustrating image formation of an electron beam on a sample in the first example of FIG.

FIG. 3 is a diagram schematically showing a second example of the embodiment of the present invention.

FIG. 4 is a diagram schematically showing a third example of the embodiment of the present invention.

FIG. 5 is a diagram schematically showing a fourth example of the embodiment of the present invention.

FIG. 6 is a diagram schematically showing a fifth example of the embodiment of the present invention.

FIG. 7 is a diagram schematically showing a sixth example of the embodiment of the present invention.

FIG. 8 is a diagram schematically showing a seventh example of the embodiment of the present invention.

FIG. 9 is a diagram schematically showing a conventional scanning tunneling microscope.

[Explanation of symbols]

2 '... micro probe, 3 ... sample, 4 ... Z driver, 5 ... XY driver, 6 ... Z moving mechanism, 7 ... driving power supply, 8 ... scanning power supply,
9 ... Control power supply, 10 ... Tunnel current detector, 11 ... Voltage application power supply, 13 ... Image display device, 14 ... Ultra-high vacuum surface observation device, 15 ... Support cylinder, 16 ... XYZ driver, 18 ...
Filament, 19 ... Emitter, 21 ... First electrode, 22
… Second electrode, 23… Ultra high vacuum chamber, 24… Control power supply, 25
… Heating power supply, 26… Drawing power supply, 27… Acceleration power supply,
28 ... 1st switch, 29 ... 2nd switch, 30 ... Secondary electron detector, 32 ... Electron beam or ion beam, 3
3 ... 3rd electrode, 34 ... Lens power supply, 35 ... Bulb, 36
... Gas cylinder, 37 ... Magnetic field lens, 38 ... Power source for magnetic field lens, 39 ... Electrostatic deflector, 40 ... Power source for electrostatic deflector, 4
DESCRIPTION OF SYMBOLS 1 ... Cover, 42 ... Sample stage, 43 ... Ultra high vacuum flange, 44 ... 1st base, 45 ... Stack vibration isolation mechanism, 4
6 ... Second base, 47 ... Slide mechanism

─────────────────────────────────────────────────── --- Continuation of front page (56) References JP-A-6-111745 (JP, A) JP-A-3-81941 (JP, A) JP-A-4-318403 (JP, A) JP-A-6- 117847 (JP, A) JP 4-4548 (JP, A) JP 9-231936 (JP, A) JP 63-298951 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 37/28

Claims (9)

(57) [Claims] 1. An ultra-high vacuum chamber in which an ultra-high vacuum is maintained, an emitter provided in the ultra-high vacuum chamber for emitting an electron beam or an ion beam toward a sample, and in the ultra-high vacuum chamber. A first electrode that is provided between the emitter and the sample and is an extraction electrode that extracts the electron beam or the ion beam from the emitter, and an electrode for forming an image of the electron beam or the ion beam on the sample A second electrode that is the closest to the sample and is an acceleration electrode, and a microprobe provided on the sample facing side of the second electrode or a cover located between the second electrode and the sample, and the microprobe. A Z movement mechanism for moving the probe toward or away from the sample, an XY driver for XY scanning of the sample, and a gap between the micro probe and the sample were adjusted. Z drive for the purpose, a voltage application power source for applying a voltage between the microprobe and the sample, a detector for detecting a current flowing between the microprobe and the sample, and the sample And a secondary electron detector for detecting secondary electrons emitted from the ultra-high vacuum surface observation apparatus. 2. The focal length of the electrostatic lens formed by the electrodes is adjustable.
The ultra-high vacuum surface observation device described. 3. The ultrahigh vacuum surface observing apparatus according to claim 1, further comprising a deflector for changing and controlling a radiation direction of the electron beam or the ion beam with respect to a sample. 4. The ultra high vacuum according to claim 1, further comprising an inert gas supply device for supplying an inert gas such as argon gas into the ultra high vacuum chamber. Surface observation device. 5. The emitter, the electrode, and the X
A YZ driver is provided in a support cylinder provided in the ultra-high vacuum chamber, and the support cylinder is moved by the Z moving mechanism to move the microprobe to or away from the sample. The ultra-high vacuum surface observing device according to any one of claims 1 to 4. 6. The ultra-high vacuum surface observation apparatus according to claim 5, wherein the secondary electron detector is provided such that its detection end is located in the support cylinder. 7. The super according to claim 5, wherein the support cylinder and the sample stage that supports the sample including the XY driver and the Z driver are formed as an integrated body. High vacuum surface observation device. 8. An ultrahigh vacuum chamber in which an ultrahigh vacuum is maintained, an emitter provided in the ultrahigh vacuum chamber for emitting an electron beam or an ion beam toward a sample, and the ultrahigh vacuum chamber. Provided between the emitter and the sample, the electron beam from the emitter or the electron beam is emitted.
The electrode that draws the on-beam and the
A lens provided between the electrode and the sample for imaging the electron beam or the ion beam on the sample.
And the magnetic field lens positioned closest to the sample as a's, a small tip provided in the magnetic field lens facing the front Symbol sample, and Z movement mechanism to close or away from the micro probe relative to the sample , XY for XY scanning the sample
A driver, a Z driver for adjusting the distance between the microprobe and the sample, a voltage application power supply for applying a voltage between the microprobe and the sample, and the microprobe. An ultrahigh vacuum surface observing apparatus comprising: a detector for detecting a current flowing between the sample and the secondary electron detector for detecting secondary electrons emitted from the sample. 9. A detection mode by a detector that detects a current flowing between the microprobe and the sample and a detection mode by a secondary electron detector that detects secondary electrons emitted from the sample. The ultra-high vacuum surface observation apparatus according to any one of claims 1 to 8, further comprising a switch which is set and which switches and sets both of these detection modes.