JP2001084951A - Working observation device and sample working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working observation device capable of observing and analyzing the state of a cross section being worked by an FIB (focused ion beam) apparatus during processing. SOLUTION: In order to observe a worked cross section being worked by an FIB, the axis of the electron optics system of a scanning electron microscope(SEM) 40 is set vertical to the axis of the ion-optics system of an FIB device 20. Additionally, the drive shaft of a stage mechanism 70 is set vertical to the axis of the ion-optics system and the axis of the electron-optics system as well. In order to monitor the worked cross section state in FIB working simultaneously with the working, signal detectors 31, 51 are provided for the FIB device 20 and the SEM 40, respectively, and a beam scanning control circuit and an image display control circuit are provided for each of the devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing observation apparatus capable of processing a sample by a focused ion beam apparatus and observing and analyzing a sample cross section during processing with one apparatus, and using the processing observation apparatus. It relates to a sample processing method.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased and the patterns formed have become finer, the resolution of optical devices has been insufficient when inspecting semiconductor devices. For this reason, an electron beam device or an ion beam device is used as a process monitor for manufacturing a semiconductor device.
It is considered that the semiconductor device will be further miniaturized and the degree of integration will be increased in the future. As the semiconductor device inspection device, a semiconductor inspection device using a charged particle beam instead of an optical semiconductor inspection device, for example, a length measuring SEM (Scannningelectro
n microscope) and focused ion beam (Focused ion bea)
m: FIB) devices are becoming increasingly important.

In particular, when performing a failure analysis of a semiconductor manufacturing process, observation of a cross section of a sample is effective. For example,
Defective parts of the sample are specified by a foreign substance inspection device or a visual inspection device, and the specified defective portions are processed by a FIB device to form a cross section, and the cross section is formed by FIB and a scanning electron microscope (Scanning ellipse).
The structure is analyzed by observation with an ectron microscope (SEM) or a transmission electron microscope (TEM). An energy dispersive X-ray analyzer (Energy dispersive X-ray analyzer)
persive spectrometer (EDS) is used.

[0004]

SUMMARY OF THE INVENTION Semiconductor device TE
In the case of producing an M sample, an FIB apparatus capable of performing a sputter processing aiming at a specific place has been actively used in recent years. However, as the miniaturization of semiconductor devices progresses, it becomes more and more important to process a specific position with high accuracy.
It is necessary to process to a thickness of less than μm. Further, as the multilayer structure of a semiconductor device advances, the thickness of the device increases, and the failure analysis location is often located deep from the surface. In this case, the processing location is not known from the surface, but a failure analysis location that cannot be identified from such a surface is referred to as T.
Processing into EM samples is desired.

The present invention has been made to meet such a demand, and provides a processing observation apparatus and a sample processing method capable of controlling the FIB processing while confirming the state of the cross section of the sample processed by the FIB apparatus. The purpose is to do.

[0006]

According to the present invention, in order to observe a processing section of a sample being processed by the FIB with a scanning electron microscope (SEM), the electron beam of the SEM is adjusted with respect to the optical axis of the ion optical system of the FIB apparatus. The optical axis of the system was arranged vertically. Further, the drive axis of the stage mechanism was set perpendicular to both the optical axis of the ion optical system and the optical axis of the electron optical system. A signal detector is provided in each of the FIB device and the SEM in order to simultaneously monitor the state of submicron microscopic parts in the processing cross section during FIB processing, and beam scanning control for image display is performed in each device. Circuit and image display control circuit. As a result, the FIB device and the SEM
Enables simultaneous observation.

Since the image observation direction by the FIB apparatus and the image observation direction by the SEM are different by 90 °, the moving direction of the stage mechanism and the movement of the image are matched, and the same image (for example, a character F is drawn on a sample) Therefore, the driving direction of the stage mechanism and the polarity of the beam deflection are set as shown in FIG.

In order to obtain a clear image with each device,
The FIB device is adapted to detect and display an ion image and a secondary electron image, and the SEM is capable of detecting and displaying a secondary electron image and a reflected electron image. When the FIB device detects an ion image, the pull-in voltage of the detector is set to a negative value, and when the secondary electron image is detected, the pull-in voltage is set to a positive value. When a secondary electron image is detected by the SEM, the pull-in voltage of the detector is set to be positive, and when a reflected electron image is detected, the pull-in voltage of the detector is set to zero. The images were displayed in the following four combinations shown in Table 1 so that the processed cross section could be observed by SEM during FIB processing.

[0009]

[Table 1]

At the same time during FIB processing, F
Combinations that can provide a clear image of the IB processing section are shown in Table 1
Or a combination of two. Therefore, during FIB processing, the SEM image display was a reflected electron image to eliminate secondary electrons. As a result, a clear image not affected by the secondary electrons generated in the FIB device was obtained.

The reason for this is that FIB and SEM
And secondary electrons are mixed and detected in the secondary electron detection, but the generation of secondary ions is physically limited to only FIB and the generation of reflected electrons is limited to only SEM. . Therefore, since information on secondary ions and reflected electrons does not mix between the apparatuses, a clear image of the FIB processed cross section can be obtained by performing simultaneous observation with a combination of 1 and 2 in Table 1.

A processing observation apparatus according to the present invention comprises a sample chamber,
A FIB apparatus column, an SEM column, and a stage mechanism fixed to the sample chamber and holding and driving the sample holder; the ion beam optical axis of the FIB apparatus column, the electron beam optical axis of the SEM column, and the sample holder of the stage mechanism It is characterized in that one axis of the drive shaft is orthogonal to each other. The FIB apparatus column includes an ion source, an ion optical system for focusing the ion beam emitted from the ion source and irradiating the sample with a beam, a deflector for controlling the deflection of the ion beam, and the like. The SEM column includes an electron source, An electron optical system for converging the electron beam emitted from the electron source and irradiating the sample with the electron beam, a deflector for controlling the deflection of the electron beam, and the like are provided.

The stage mechanism is a side entry type stage mechanism. The sample holder mounted on the side entry type stage mechanism can rotate 360 ° around the one axis of the stage mechanism in 90 ° steps. With this structure, the cross section of the TEM sample processed by FIB is SE
M allows observation and analysis of the front and back.

This processing observation apparatus uses a FI
A position adjusting mechanism for adjusting the position of at least one of the B apparatus column and the SEM column is provided. The position adjustment mechanism adjusts the cross section processed by the FIB apparatus so as to enter the observation field of view of the SEM without moving the stage mechanism.
The same field of view is obtained between the FIB device and the SEM by mechanically aligning the field of view of the FIB device with the field of view of the SEM to a range (within ± 20 μm) that can be adjusted by the image shift function using scanning electron beam deflection of the SEM by the position adjustment mechanism. be able to.

The FIB device has a function of switching and displaying an ion image and a secondary electron image, and the SEM has a function of switching and displaying a reflected electron image and a secondary electron image. Switching between the ion image and the secondary electron image or switching between the reflected electron image and the secondary electron image can be performed, for example, by switching the pull-in voltage of the detector. When displaying an ion image, the pull-in voltage of the detector is made negative. When displaying a secondary electron image, the pull-in voltage of the detector is made positive. Further, when displaying a reflected electron image, the pull-in voltage of the detector is set to a negative value so that secondary electrons do not enter the detector.

In the case where an energy dispersive X-ray analyzer is installed in the processing observation device, it is preferable that the detector of the energy dispersive X-ray analyzer be movable so that it can be retracted to a position where the FIB processing position is not directly expected. . Further, it is preferable to attach a removable protective film to the tip of the detector of the energy analysis type X-ray analyzer. A sample processing method according to the present invention is characterized in that a FIB processing section is processed by FIB while observing a FIB processed cross section of the sample by SEM using the processing observation apparatus. This method is particularly effective for processing a specific minute portion of a sample of submicron or less by FIB.

The end point of the processing can be easily detected by processing the FIB processed cross section of the sample with the FIB while observing the reflected electron image with a SEM or analyzing the processed cross section with an energy dispersive X-ray analyzer. it can. SEM
Observation of the backscattered electron image is performed by switching the SEM signal detector to the backscattered electron detector, or turning off or weakening the pull-in voltage of the secondary electron detector to detect the backscattered electrons but not to capture the secondary electrons. Do. During FIB processing, the FIB apparatus observes an ion image of the sample.

Secondary electron image, secondary ion image by FIB,
Information obtained from the secondary electron image and the reflected electron image by the SEM is different from each other. For example, although the secondary electron image of the SEM has a high resolution, information on crystal grains cannot be obtained. On the other hand, information on crystal grains can be obtained from the secondary ion image. Thus, by comparing each of these images, more information about the sample can be obtained.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating an example of a system configuration of a processing observation device according to the present invention. This processing observation apparatus includes a FIB column 20, a SEM column 40, a sample chamber 60, a stage mechanism 70, a sample holder 80 mounted on the stage mechanism 70 to hold the sample 10 as described later, an EDS detector 95, a W (tungsten) ) Depot gun 9
6. It has a detector 31 for FIB device and a detector 51 for SEM. The insides of the sample chamber 60, the FIB column 20, and the SEM column 40 are evacuated by a vacuum exhaust device 65.

Since FIB has a large sputtering effect unlike an electron beam, it can be used for fine processing of the sample 10. Therefore, the FIB device is used as a processing machine and an observation device for processing a TEM sample or for processing a cross section of a SEM sample.
EM is used as an analyzer for observation of processed samples and EDS. The W deposition gun 96 is for depositing an ion beam-induced W film on a processed sample to form a protective film. The EDS analyzer 95 performs X-ray analysis by detecting X-rays generated from the sample 10 by SEM electron beam irradiation.

In order to observe the processed cross section of the sample 10 being processed by the FIB, the axis of the ion optical system of the FIB apparatus is set to S.
The EM was arranged such that the axis of the electron optical system was vertical. Further, the stage mechanism 70 has one of its drive axes perpendicular to the axis of the ion optical system and the axis of the electron optical system. In addition, during FIB processing, signal detectors 31 and 51 are provided in the FIB apparatus and the SEM, respectively, in order to simultaneously monitor the processing cross-sectional state of the submicron minute portion of the sample.
Each device was provided with a beam scanning control circuit and an image display control circuit. This allows simultaneous observation by FIB and SEM at independent magnifications. However, the above FI
Even if the axis of the ion optical system of the apparatus B and the axis of the electron optical system of the SEM were not exactly orthogonal, it was useful if they were approximately orthogonal.

FIG. 2 is an explanatory diagram of the sample holder 80 and the stage mechanism 70. The sample holder 80 includes a pin 81,
The apparatus includes shafts 83 and 84, a sample fixing portion 85, a handle 86, and a sample direction switching knob 87. The sample 10 is fixed to the sample fixing section 85. The sample fixing part 85 is the shaft 8
3, the shaft 83 penetrates through the inside of the shaft 84 and the handle 86, and a sample direction switching knob 87 is attached to an end of the shaft 83. Therefore, when the sample direction switching knob 87 is turned, the shaft 83 rotates with respect to the shaft 84.

The sample holder 80 is mounted on a stage mechanism (side entry type stage mechanism) 70 mounted on the wall of the sample chamber 60. The stage mechanism 70 has a shaft insertion hole 71 and a groove 72. When the pin 81 on the shaft 84 is aligned with the position of the groove 72 of the stage mechanism 70 and the shaft 84 of the sample holder 80 is inserted into the shaft insertion hole 71, the sample holder 80
Is guided by the groove 72, and is positioned and inserted into the stage mechanism 70. The stage mechanism 70 has the shaft insertion hole 7
The shaft 84 of the sample holder 80 inserted into the holder 1 can be kept airtight, and the sample holder 80 can be driven in two directions orthogonal to the holder insertion direction and the holder insertion direction and in the θ direction. When the sample direction switching knob 87 of the sample holder 80 held by the stage mechanism 70 is turned, the shaft 83 and the sample fixing portion 8 are rotated about the sample holder insertion direction as an axis.
5 rotates. The sample direction switching knob 87 can be rotated stepwise by 90 °.

With this structure of the sample holder 80, F
The cross section of the sample processed by IB can be observed by SEM, and the direction of the sample is rotated by 90 °, and the SEB is set by FIB.
It becomes possible to observe the same sample section as the sample section observed in M. A difference occurs between a secondary electron image formed by secondary electrons emitted from a sample by ion irradiation and a secondary electron image formed by secondary electrons emitted from a sample by electron beam irradiation, even with the same secondary electron image. By using the sample holder 80, a secondary electron image at the same position of the sample can be observed by the FIB apparatus and the SEM by rotating the sample by 90 °, so that much information about the sample cross section can be easily obtained. it can.

FIG. 3 is a view for explaining the relationship among the direction of incidence of the ion beam of the FIB apparatus, the direction of incidence of the electron beam of the SEM, and the direction of movement of the stage mechanism. As shown in FIG. 3A, the direction of incidence of the ion beam of the FIB apparatus is perpendicular to the direction of incidence of the electron beam of the SEM, and the direction of inserting the holder (the axis of the stage mechanism) is perpendicular to both directions. FIG.
As shown in the figure, the X, Y, and Z directions viewed from the SEM are FI
The B apparatus corresponds to the X, Z, and Y directions, respectively. In this case, the SEM image does not move even if Z is adjusted with the SEM,
The image observed by the FIB device moves in the Y direction. By utilizing this, the observation points of the FIB apparatus and the SEM can be matched.

FIG. 3B is a FIB image of the sample surface observed by the FIB apparatus when the sample is in the posture of FIG. 3A. FIG. 3 (c) shows the S section of the sample section observed by SEM.
It is an EM image. The sample holder 4 is made of T
The cross section of the EM sample can be rotated 360 ° in 90 ° steps so that the front and back sides can be observed and analyzed by SEM. In order to make the movement direction of the stage mechanism 70 coincide with the movement of the image and to allow the same image to be observed by the SEM and the FIB device, for example, when the image of the sample on which the character F is drawn is observed, the SEM is also used by the FIB device. However, in order to make it appear as F, the driving direction of the stage mechanism and the polarity of beam deflection are set to the relationship shown in FIG.

In order to obtain the same field of view with the FIB device and the SEM, the range (±) which can be adjusted by the image shift mechanism of the SEM.
An adjustment mechanism for mechanically matching the field of view of the FIB apparatus and the SEM up to 20 μm) was provided at the sample chamber mounting portion of the SEM lens barrel.

FIG. 4 is an explanatory view of a mechanism for adjusting the field of view of the FIB apparatus and the SEM. FIG. 4A is a side view showing the SEM column attached to the sample chamber, and FIG.
It is the figure which looked at the M column in the optical axis direction. As shown in FIG. 4A, the SEM column 40 has an O-ring 61
It is mounted with a vacuum shield. The sample chamber 60 and the SEM column 40 are evacuated and maintained at a high vacuum by a vacuum pump. SEM column mounting flange 5
9, there is a ring-shaped position adjusting plate 62 fixed to the sample chamber 60, and the position adjusting plate 62 has position adjusting screws 63.
Are provided at four locations. 4 position adjustment screws 63
The position of the SEM column 40 with respect to the sample chamber 60 can be adjusted by adjusting the amount of extrusion.

Using this adjustment mechanism, the FIB device and the SE
The field of view of M was adjusted to a range (within ± 20 μm) that could be adjusted by SEM image shift. FIB equipment and SEM
In the field of view adjustment, the sample image is observed by, for example, the FIB device, and then the sample direction switching knob 87 of the sample holder 80 is turned by 90 ° to turn the sample observation surface of the FIB device toward the SEM. Then, while watching the sample image by the SEM, the position of the SEM column 40 with respect to the sample chamber 60 is adjusted by the position adjusting screw 63 of the position adjusting plate 62 so that the image matches the sample image by the FIB apparatus. Matching the field of view of the FIB device with the field of view of the SEM corresponds to matching the axis of the SEM with the intersection of the X axis of the stage mechanism 70 and the optical axis of the FIB. If the field of view of the FIB apparatus matches the field of view of the SEM, the same point on the sample can be observed with the FIB apparatus and the SEM by rotating the sample fixing portion 85 of the sample holder 80 by 90 °.

FIG. 5 is a schematic diagram showing the system configuration of the sample processing observation apparatus according to the present invention. Ga ion beam 2 extracted from Ga liquid metal ion source 21 of FIB apparatus
2 is accelerated to 30 kV, passes through the beam limiting aperture 23, is focused by the objective lens 24, and irradiates the solid sample 10. Upon receiving a command to start beam scanning from the control computer 90, the beam scanning signal generator 25 passes the beam scanning signal to the deflector controller 26, and the deflector controller 26 generates a voltage based on the scanning (deflection) signal. Then, a voltage is applied to the deflector 27. The deflection of the ion beam 22 is controlled so as to scan the sample 10.

Secondary electrons 11 and secondary ions 1 generated from solid sample 10 by irradiation with ion beam 22
2 is detected by a detector 31, amplified by a preamplifier 32, and converted into an electric signal. The detector 31 has an MCP that can selectively detect the secondary electrons 11 and the secondary ions 12 according to whether the detection voltage (pull-in voltage) is positive or negative.
(Microchannel plate) was used. The detection signal is subjected to luminance modulation of the scanning signal in synchronism with the deflection signal from the deflector control device 26 to be displayed as an image on the monitor 33 of the workstation (WS).
At 4 the image is digitized and stored in memory. The data of the signal processing device 34 is passed to and controlled by the control computer 90.

Similarly, the electron beam 42 extracted from the electron source 41 of the SEM is accelerated to a maximum of 30 kV, passes through the beam limiting aperture 43, is focused by the objective lens 44, and irradiates the solid sample 10. Scanning signal generator 45
Receives a command to start beam scanning from the control computer 90, passes a scanning signal to the deflector controller 46, and the deflector controller 46 generates a voltage based on the scanning (deflection) signal, and applies a voltage to the deflector 47. Apply. Thus, the deflection of the electron beam 42 is controlled so as to scan the sample 10.

Secondary electrons 13 and reflected electrons 14 generated from solid sample 10 by irradiating electron beam 42
Is detected by the detector 51, amplified by the preamplifier 52, and converted into an electric signal. As the detector 51, depending on whether the detection voltage (pull-in voltage) is positive or zero, the secondary electrons 13
A YAG semiconductor detector capable of selectively detecting the reflected electrons 14 and the reflected electrons 14 was used. The amplified detection signal is supplied to the deflection controller 46.
The scanning signal of the monitor is luminance-modulated in synchronism with the deflection signal, and the image is displayed on the monitor 53 of the WS. At the same time, the image is digitized by the signal processor 54 and stored in the memory. The data of the signal processing device 54 is passed to and controlled by the control computer 90.

FIG. 6 is an explanatory diagram showing the energy distribution of secondary particles generated from a sample by electron beam irradiation. In general,
Electron beam irradiation generates secondary electrons and reflected electrons. The energy of the secondary electron has a peak at about 4 eV, and extends from the peak to about 50 eV while decreasing. Also, the energy of the reflected electrons has a peak near the energy equal to the irradiation energy.

FIG. 7 is an explanatory diagram showing an energy distribution of secondary particles generated from a sample by ion irradiation. In the case of ion irradiation, as in the case of electron beam irradiation, there is a peak at about 4 eV, and then secondary electrons which decrease and spread to about 50 eV are generated, but no reflected electrons are generated. Instead,
Secondary ions are generated by the sputtering action of the ion beam.

Therefore, in order to increase the detection efficiency of the secondary electrons, a voltage of about several volts to be applied to the detector is required near the secondary electron generation point. On the other hand, reflected electrons have high energy and do not require a drawing voltage. For this reason, the backscattered electrons are directly captured by the detector, but the backscattered electron detection efficiency deteriorates in inverse proportion to the square of the distance from the point of occurrence. Therefore, the backscattered electrons are detected near the point of occurrence so that the detected solid angle increases. Secondary ions have a polarity opposite to that of secondary electrons, and the energy distribution is slightly lower than the secondary electrons, but the distribution is very similar. Therefore, a negative pull-in voltage is applied for secondary ion detection. Of course, this condition precludes the detection of electrons.

In order to display a clear image, the detector of the FIB apparatus uses an MCP (multi-channel plate) to detect and display an ion image and a secondary electron image.
The M detector can detect and display a secondary electron image with a scintillator and a PHM (photomultiplier) detector and a reflected electron image with an SSD (semiconductor detector) detector. There are eight types of image display combinations as shown in Table 2 below.

[0038]

[Table 2]

1 or 2 in Table 2 shows a state in which the secondary electron image or the reflected electron image is observed by the SEM. At this time, the ion beam apparatus is not operated or the detector is turned off. And a clear image could be obtained by SEM. Table 2-3
Or 4 is a state in which a secondary electron image or an ion image is observed with the FIB apparatus, and at this time, the SEM is not operating or the detector is turned off, and a clear image can be obtained with the FIB apparatus. did it. 5 in Table 2 shows the results obtained by observing the ion image with the FIB apparatus and observing the backscattered electron image with the SEM.
When the processing section was observed by SEM during processing B, FIB,
Clear images were obtained with both SEMs. Table 2-6 shows FI
When the processed cross section was observed by SEM during FIB processing in the state where the secondary electron image was observed by the B apparatus and the reflected electron image was observed by SEM, a clear image was obtained by SEM. Table 2-7
In the state of observing the ion image with the FIB apparatus and observing the secondary electron image with the SEM, the processing cross section is S
When the EM was observed, a clear image was obtained with the FIB apparatus. However, the SEM image was unclear. 8 in Table 2
In the state in which secondary electrons are detected by both the FIB device and the SEM, when the processed cross section is observed by the SEM during the FIB processing, the two electron beams generated by the FIB device, the SEM, and the respective detectors are detected by both devices. The next electron signal is superimposed and detected, and FI
Both the image of the apparatus B and the image of the SEM were unclear.

Observation by SEM of the processed cross section during FIB processing was possible from 5 to 8 in Table 2 except for clear or unclear, but from the viewpoint of obtaining a clear image, 5 or 6 in Table 2 was possible.
Among them, the simplest method is a method of observing a secondary electron image with an FIB apparatus 6 and observing a reflected electron image with an SEM. By comparing the same cross section with the FIB secondary electron image, secondary ion image, SEM secondary electron image, and reflected electron image by the function of changing the detection mode of the detector, semiconductor failure analysis and structure It was useful for analysis.

The stage mechanism can be operated from the stage mechanism console and the stage mechanism control screen of the WS of the FIB device. The display of the stage mechanism console is S
It was adjusted to the moving direction of the stage mechanism as seen by EM. on the other hand,
The display of the WS stage mechanism control screen is FIB
It was adjusted to the moving direction of the stage mechanism seen by the device. Also,
When moving the stage mechanism, the coordinate values are displayed in conjunction with the stage mechanism control screen and the stage mechanism console. As for the moving speed of the stage mechanism, a speed changeover switch was provided on the stage mechanism console. Also, the moving speed of the stage mechanism is changed in conjunction with the magnification of the FIB device.

Also, in order to perform EDS analysis by SEM,
When the signal extraction angle of the EDS detector 95 is optimized and EDS is not used, a shutter is provided at the tip of the EDS detector 95 and EDS is generated by sputter particles generated by FIB processing.
The DS detector 95 was prevented from being contaminated. Also, FIB
In order to perform EDS analysis during processing, an organic protective film was provided at the tip of the EDS detector 95 so that the EDS detector 95 was not directly contaminated by sputter particles generated during FIB processing.

FIG. 8 is a view for explaining an example of a sample processing method using the processing observation apparatus of the present invention. This example shows an example in which a semiconductor device is processed by an FIB apparatus to create a cross section of a contact hole portion. The posture of the sample with respect to the FIB incident direction and the SEM electron beam incident direction is as shown in FIG.

The FIB apparatus worked while applying a negative pull-in voltage to the detector and observing the secondary ion image. The SEM used a semiconductor detector to which a positive voltage was applied as a detector, observed the reflected electron image of the processed cross section in real time while suppressing the incidence of secondary electrons. At this time, as the processing proceeds, the backscattered electron image of the SEM is shown in FIGS.
It changed like (c). The operator monitors the backscattered electron image of the SEM, and finishes the FIB processing when the cross section of the contact hole 101 appears as shown in FIG. 8C.

FIG. 9 is a view for explaining another example of a sample processing method using the processing observation apparatus of the present invention. This example is an example in which a sample is subjected to FIB processing in order to examine a foreign substance in the sample. The posture of the sample with respect to the FIB incident direction and the SEM electron beam incident direction is as shown in FIG. ED
The energy level of the S detector was previously adjusted to the characteristic X-ray of the foreign matter.

The FIB apparatus worked while applying a negative pull-in voltage to the detector and observing the secondary ion image. The SEM used a semiconductor detector to which a positive voltage was applied as a detector, observed the reflected electron image of the processed cross section in real time while suppressing the incidence of secondary electrons. Further, X-ray analysis generated from the cross section of the sample by SEM electron beam irradiation by the EDS detector was also performed at the same time. As the processing progresses, S
The reflected electron image of the EM changed as shown in FIGS. 9 (a), 9 (b) and 9 (c). Further, as the processing progressed, the EDS analysis signal intensity changed as shown in FIG. 9D as the FIB processing progressed. The operator is responsible for the SEM backscattered electron image and EDS
The analysis signal intensity was monitored, and SEM was performed as shown in FIG.
FIB processing was stopped at a time t = t ₃ at which the foreign substance 102 largely appeared in the image and the substance analysis result of the foreign substance by EDS analysis became maximum.

[0047]

According to the present invention, FIB processing can be controlled while confirming the state of the cross section of the sample being processed by the FIB apparatus by SEM. This makes it possible to perform FIB processing on a specific position of the sample with high accuracy, and to perform processing with a thickness of 0.1 μm or less with a processing position accuracy of 0.1 μm or less.
In addition, a sample whose processing location is not known from the sample surface is T
Can be processed into EM samples.

Further, abundant information can be obtained by comparing the secondary electron image by FIB, the secondary ion image, the secondary electron image by SEM, and the reflected electron image obtained from the same cross section of the sample. Can be used for failure analysis and the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a system configuration of a processing observation device according to the present invention.

FIG. 2 is an explanatory view of a sample holder and a stage mechanism.

FIG. 3 is a view for explaining a relationship among an ion beam incident direction of an FIB apparatus, an electron beam incident direction of an SEM, and a moving direction of a stage mechanism.

FIG. 4 is an explanatory diagram of a field-of-view adjusting mechanism of the FIB device and the SEM.

FIG. 5 is a schematic diagram showing a system configuration of a sample processing observation apparatus according to the present invention.

FIG. 6 is an explanatory diagram showing an energy distribution of secondary particles generated from a sample by electron beam irradiation.

FIG. 7 is an explanatory diagram showing an energy distribution of secondary particles generated from a sample by ion irradiation.

FIG. 8 is a diagram illustrating an example of a sample processing method using the processing observation device of the present invention.

FIG. 9 is a view for explaining another example of the sample processing method using the processing observation device of the present invention.

[Explanation of symbols]

10 ... sample, 11 ... secondary electron, 12 ... secondary ion, 13
... secondary electrons, 14 ... reflected electrons, 20 ... FIB columns, 2
DESCRIPTION OF SYMBOLS 1 ... Ion source, 22 ... Ion beam, 23 ... Beam limiting aperture, 24 ... Objective lens, 25 ... Beam scanning signal generator, 26 ... Deflector controller, 27 ... Deflector, 31
Detector for FIB device, 32 Preamplifier, 33 Monitor, 34 Signal processor, 40 SEM column, 41
... Electron source, 42 ... Electron beam, 43 ... Beam limiting aperture, 44 ... Objective lens, 45 ... Scan signal generator, 4
6: Deflector control device, 47: Deflector, 51: SEM detector, 52: Preamplifier, 53: Monitor, 54: Signal processing device, 59: SEM column mounting flange, 60:
Sample chambers 60, 61: O-ring, 62: Position adjusting plate, 63
... Position adjusting screw, 65 ... Vacuum exhaust device, 70 ... Stage mechanism, 71 ... Shaft insertion hole, 72 ... Groove, 80 ... Sample holder, 81 ... Pin, 83 ... Shaft, 84 ... Shaft, 85 ... Sample fixing part, 86 … Handle, 87… sample direction switching knob, 90… control computer, 95… EDS
Detector, 96 ... W depot gun, 101 ... Contact hole,
102: Foreign matter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidemi Koike 882, Omo, Oaza, Hitachinaka-shi, Ibaraki Prefecture Within the measuring instruments group of Hitachi, Ltd. Hitachi Science Systems, Ltd. (72) Inventor Norifumi Yukita 1040, Oji-shi, Oita, Hitachinaka-shi, Ibaraki Co., Ltd. F-term (reference) in Sangyo Sangyo Co., Ltd. 5C001 AA03 AA04 AA06 CC03 CC04 5C033 NN01 NN02 NN05 NP06 UU04 UU06 5C034 DD05 DD06

Claims (9)

[Claims] 1. A sample chamber, a focused ion beam device column, a scanning electron microscope column, and a stage mechanism fixed to the sample room and holding and driving a sample holder, wherein ions of the focused ion beam device column are provided. A processing observation apparatus, wherein a beam optical axis, an electron beam optical axis of the scanning electron microscope column, and one axis of a sample holder driving axis of the stage mechanism are substantially orthogonal to each other. 2. The processing observation apparatus according to claim 1, wherein
A processing observation apparatus characterized in that the sample holder can be rotated 360 ° around the one axis of the stage mechanism in 90 ° steps. 3. The processing observation apparatus according to claim 1, further comprising a position adjusting mechanism for adjusting at least one of the focused ion device column and the scanning electron microscope column with respect to the sample chamber. Processing observation device. 4. The processing and observation device according to claim 1, wherein the image magnification of the focused ion beam device and the image magnification of the scanning electron microscope can be controlled independently. 5. The scanning electron microscope according to claim 1, wherein the focused ion beam device has a function of switching and displaying an ion image and a secondary electron image. A processing observation apparatus having a function of switching and displaying a reflected electron image and a secondary electron image. 6. A sample processing method using the processing and observation apparatus according to claim 1, wherein the focused ion beam processing section is processed with a focused ion beam while observing a focused ion beam processed cross section of the sample with a scanning electron microscope. A sample processing method comprising: 7. A sample processing method using the processing observation apparatus according to claim 1, wherein the focused ion beam processing section of the sample is observed by a scanning electron microscope while observing a reflected electron image. A sample processing method characterized by processing by: 8. A sample processing method using the processing observation apparatus according to any one of claims 1 to 5, wherein a processing section of the sample during focused ion beam processing is analyzed by an energy dispersive X-ray analyzer. A sample processing method characterized by processing with a focused ion beam. 9. The sample processing method according to claim 6, wherein the focused ion beam apparatus observes an ion image of the sample during the focused ion beam processing.