JPH06103947A - Focusing ion beam device - Google Patents

Abstract

PURPOSE:To make the replacement of a sample unnecessary during the works of a preprocess of FIB process, an FIB process, an afterprocess of FIB process, a SEM observation, and a TEM observation, and to make the identification of the processing position and the analizing position easy, so as to improve the processing and observing efficiency extensively, by giving the same coordinates system to the two positions. CONSTITUTION:This focusing ion beam device is composed of an ion source, a column system, a sample chamber, and a control system (not shown in the Figure). The ion source is composed of an emitter 1, a shield electrode 2, and a draw-out electrode 3. The column system is composed of a capacitor lens 4, a restriction 5, a scanning electrode 6, and an object lens 7. And the sample chamber 8 is composed of a sample fine adjustment device 10, a sample holder 11, and a secondary particle detector 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focused ion beam apparatus and, more particularly, to a focused ion beam apparatus capable of efficiently performing a working operation without displacing a minute sample until the observation after processing.

[0002]

2. Description of the Related Art Conventionally, for example, a focused ion beam (FI) is used.
B) After processing the sample with the device, a transmission electron microscope (TE
When M) is used to observe the processed part, the sample is small, so that it takes a great deal of concentration and time to replace the sample. If there is a problem in FIB processing and FIB processing becomes necessary again after TEM observation, the difficulty will be compounded. It would be convenient if not only small samples but also relatively large samples could be operated without remounting the samples.

[0003]

In the focused ion beam apparatus of the present invention, a focused ion beam (FIB) apparatus, a transmission electron microscope, a scanning electron microscope (TEM), an etching apparatus, etc. are used to observe or process a sample. It is to eliminate the need for remounting and to enable efficient analysis or analysis work.

[0004]

In order to solve the above-mentioned problems, the system of the present invention adopts a side-entry method for the sample holder, and by sharing this holder, the sample is not replaced. However, it enables processing by FIB and observation by TEM and SEM. TE
In the case of M sample preparation, it is necessary that the sample can be processed or observed even if it is rotated at least 90 degrees in order to enable sharing of the holder. Therefore, in the present invention, the side with a notch is provided. The entry sample holder is shown as an example.

[0005]

Function: The FIB-processed sample holder can be directly pulled out and inserted into a TEM or SEM for observation. When it is desired to quickly match the processing position and the observation position, the displayed sample position is made to match the sample position of another device. As a means in this case, the display value of another device may be manually input, or the position information may be directly communicated and linked.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.
This device comprises an ion source, a column system, a sample chamber, and a control system (not shown). The ion source is composed of an emitter 1, a shield electrode 2 and an extraction electrode 3. The column system is composed of a condenser lens 4, a diaphragm 5, a scanning electrode 6, and an objective lens 7. The sample chamber 8 includes a sample fine movement device 10, a sample holder 11, and a secondary particle detector 9. The sample 12 is attached to the tip of the sample holder.

Next, the operation will be described by taking the sample preparation of the TEM as an example. Ga ions emitted from the emitter are extraction electrodes 3
Then, after being accelerated to about 30 kV, the diameter is reduced to several tens nm on the sample 12 by the condenser lens 4, the diaphragm 5 and the objective lens 7. This beam is scanned into an arbitrary shape by the electric field applied to the scanning electrode 6. Ions irradiated on the sample can be processed in a minute portion by sputtering the sample. On the other hand, the electrons or ions emitted during the sputtering are detected by the secondary particle detector 9, and this intensity is synchronized with the brightness signal of the CRT by the scanning of the CRT and the voltage of the scanning electrode 6, and the ion irradiation unit Can record images. The processing position is determined from this image.

Here, a semiconductor memory is considered as a sample. In the case of 4M-DRAM, the processing line width is about 0.8 μm, and when defect analysis of defects is performed using TEM, it is necessary to form a thin film of 0.8 μm or less and 100 nm or less at the center of the sample. In this case, first, a schematic size of a sample is shown in FIG. The sample is mounted as shown in FIG. FIG. 3 is an enlarged view of the tip of the sample holder. The sample 12 is fixed on the sample base 14 with an adhesive or a spring, and the sample base is fixed to the tip of the sample holder with screws 15. When fixed, it is desirable to use an optical microscope or the like so that the observation point is located on the axis of the rotation center 17 of the sample holder. Assuming that the beam is perpendicular to the plane of the drawing, F in Fig. 3 (a).
The processing position by IB, FIG. 3B shows the position when observed by TEM. In FIG. 3, the notch 16 is shown in FIG.
When the FIB processing is performed at the position, the ion beam is used for reaching the sample, and is not necessary for the sample holder of the normal TEM.

The sample thus attached is inserted into the sample fine movement device 10 together with the sample holder. Sample fine movement device 1
Reference numeral 0 is a so-called side-entry sample stage, and this mechanism includes a valve for shutting off the atmosphere from the sample chamber and a differential evacuation system for sample exchange. The description of the method for inserting the sample is omitted here. When the side entry stage is used, the sample 12 can be installed at the tip of the sample holder 11, and this part and the knob part that is out of the vacuum during use are integrated, which is convenient for the manual transfer of the sample. The inserted sample is processed by the method described above. F
The processing part by IB is the part 13 in FIG. The processed sample is pulled out together with the sample holder and inserted into the TEM sample holder for observation. In this case, since the sample 12 can be observed without touching it directly, the observation efficiency becomes very good. If the sample is attached and observed, it requires skill and time to correctly fix the sample at the observation position because the sample is small. Normally, it takes about 30 minutes to 1 hour. In addition, because of imperfect processing, FIB was performed again after TEM observation.
The difficulty is compounded, for example, in the case of processing and TEM observation again.

When a general-purpose TEM / SEM sample holder is used as it is, its size may differ depending on these models, and it may not be shared. An example of this case is shown in FIG. FIG. 4 shows only the part of the sample chamber 8,
When two types of sample holders 11 and 11 'are used, firstly, the sample holder 11' may be attached in a direction perpendicular to the sample holder 11 and the sample holder 11 'may be attached from the same direction via the conversion flange 18. The former is convenient because it is not necessary to replace the sample fine movement device 10, but because the space in the sample chamber 8 is occupied and there is a difference in angle with respect to the detector, the detection efficiency changes when the sample is tilted, and the cost increases. There are also drawbacks. The opposite is true in the latter case. The sample holders of different kinds according to the present embodiment have FIB and SE.
Processing observation became possible by connecting with M or TEM.

The side-entry sample holder has the above-mentioned advantages, but on the other hand, has a drawback that the sample variable range is narrow. In this case, it is desirable that it can be shared with a general-purpose stage. FIG. 5 shows an embodiment in this case. A general-purpose stage 19 is mounted instead of the sample fine movement device 10 'in FIG. In this embodiment, the size of the sample placed on the general-purpose stage is 4 inches, and a sample of this size can be processed.

When observing with a TEM or SEM after processing with FIB, the relationship between the processing part and the observing part may be confused, or the processing position may be difficult to find in some cases. In the embodiment of FIG. 6, the coordinate display of the sample stage shown in the figure is the same for FIB and TEM (only one is shown). The coordinate processed by FIB and the coordinate of TEM are matched by hand or by communication. Can be matched by.
This is possible and work efficiency has improved significantly. For example, conventionally, it took about 20 minutes to confirm the position, but now it can be accurately positioned within 5 minutes. If a plurality of small and identical shapes are machined and this observation is performed, it becomes more difficult to confirm the position, and the effect of the present embodiment is further enhanced.

FIG. 7 shows an embodiment in which a plurality of devices are connected by the same sample holder to improve the efficiency of a series of operations. Figure 7 is FI
B20, argon milling device 21, SEM22, TE
The sample holder 11 and the sample fine movement device 10 are common to all of these devices. For example, a surface machined with FIB20 is used for an argon milling device 2
The observation surface was etched in 1 and observed by SEM22. As a result of the observation, it was found that the cross section of the observation part needs to be processed a little deeper. Then, it is processed by FIB20 again, this surface is subjected to argon milling, and SEM observation is performed again. Further, a TEM sample is processed with FIB20 for observing a minute portion, and finally TEM observation is performed. In this case, if the sample is replaced, it takes a very long time to work, and if there is no concentration of the operator's mind, the measurement may end in trouble such as dropping the sample before reaching the final stage. With the system of the present invention, this task can be easily performed.

When the sample to be processed by FIB is an insulator, the sample surface may be vapor-deposited before the processing. It is more convenient if the same sample holder can be attached to this vapor deposition apparatus.

[0015]

According to the present invention, FIB processing pretreatment, F
In IB processing, FIB post-processing processing, SEM observation, and TEM observation work, it was not necessary to replace the sample, and the processing observation efficiency was greatly improved. The value was improved by at least 30 minutes or more in one work.

In the case of processing and observing, the apparatus of the present invention can set the coordinates in common even in the work of aligning the sample with the observing position, so that it can be set immediately. The time required for this was 15 to 30 minutes per observation, and this time was improved.

[Brief description of drawings]

FIG. 1 is an FIB explanatory diagram of the present invention.

FIG. 2 is an explanatory diagram showing the size and processed portion of a TEM sample.

FIG. 3 is an explanatory diagram of a tip portion of a sample holder.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing Embodiment 3 of the present invention.

FIG. 6 is a diagram showing a sample position display example.

FIG. 7 is a diagram showing an example of building a composite system.

[Explanation of symbols]

1 ... Emitter, 2 ... Shield electrode, 3 ... Extraction electrode, 4
... condenser lens, 5 ... diaphragm, 6 ... scanning electrode, 7 ...
Objective lens, 8 ... Sample chamber, 9 ... Secondary particle detector, 10 ...
Sample fine movement device, 11 ... Sample holder, 12 ... Sample, 14
… Sample stand, 18… Conversion flange, 19… General stage,
20 ... FIB, 21 ... Argon milling device, 22 ... S
EM, 23 ... TEM.

Claims (7)

[Claims] 1. A scanning electron microscope or a sample holder of a transmission electron microscope can be mounted on a focused ion beam apparatus as it is, and the focused ion beam processing and scanning electron microscope can be carried out without remounting the sample, or , A focused ion beam device, which can be observed by a transmission electron microscope. 2. The focused ion beam apparatus according to claim 1, wherein the sample holder can irradiate an ion beam or an electron beam even when the sample rotates at least 90 degrees. 3. The focused ion beam apparatus according to claim 1, wherein the sample holder is a side entry type. 4. The method according to claim 1, wherein the sample holders of different types of scanning electron microscopes or transmission electron microscopes can be attached at the same time or by replacement, and different types of sample holders can be used. Focused ion beam processing equipment. 5. The focused ion beam processing apparatus according to claim 4, wherein a general-purpose stage having a variable working distance and a side entry stage can be mounted. 6. When the relationship between the beam position of the focused ion beam device and the sample position and the relationship between the beam position of the scanning electron microscope or the transmission electron microscope and the sample position can be made the same and the device is changed. However, the focused ion beam device according to claim 1, wherein the processing position can be quickly set to the observation position. 7. The sample holder according to claim 1, which can be mounted on an etching apparatus, a milling apparatus, a vapor deposition apparatus, a laser processing machine or the like as it is, for observation by a focused ion beam processing, a scanning electron microscope or a transmission electron microscope. Focused ion beam processing system that can perform etching, milling, vapor deposition, laser processing, etc. before, after, or between.