JP4644084B2 - Electron microscope control apparatus, electron microscope system, and control method of electron microscope - Google Patents

Description

  The present invention relates to an electron microscope control apparatus, an electron microscope system, and an electron microscope control method.

  One of the electron microscopes is a scanning electron microscope (hereinafter referred to as SEM) and an energy dispersive X-ray analyzer (hereinafter referred to as EDX) that processes a signal from a semiconductor X-ray detector attached to the SEM. There is a combination of. This EDX is a device that performs elemental analysis of a micro area of several μm. At the same time as image observation by SEM, qualitative analysis, quantitative analysis, analysis of element distribution by X-ray image, etc. Is to do.

  In an electron microscope equipped with such an EDX, the conditions set in the SEM (SEM conditions) and the analysis conditions on the EDX side corresponding to the SEM conditions (EDX conditions) (hereinafter collectively referred to as recipes) are the past analysis conditions. Thus, the optimum analysis conditions for the sample to be measured are selected. The optimal analysis conditions here are, for example, conditions such that the dead time (dead time) in EDX falls within a predetermined range (for example, 20 to 30%). Then, the selected SEM condition and EDX condition are set to SEM and EDX.

Here, the SEM conditions are, for example, an acceleration voltage, an electron beam irradiation current adjustment value, a working distance, a magnification, an input signal, and the like. The EDX conditions are, for example, spectrum measurement conditions (measurement time, process time), , SEM image capturing conditions (SEM image size, speed), mapping conditions (map size, number of times), qualitative / quantitative conditions, and the like.
JP 2003-98129 A

However, in the above-described prior art, when the called recipe does not become the optimum analysis conditions due to the composition or shape of the sample, or when the optimum conditions differ in the observation and analysis of the sample (for example, between observation and analysis). When the required electron beam irradiation current is different), the measurer needs to repeat the operations of SEM adjustment → observation of sample by SEM → adjustment of SEM → analysis of sample by EDX → adjustment of SEM.
Here, in order to facilitate the adjustment of the SEM, a method of feeding back the measurement result on the EDX side to the SEM side and controlling the SEM side in real time can be considered.

  However, since there has been no computer (integrated application) that controls both SEM and EDX, in order to control an electron microscope equipped with EDX, an EDX computer for controlling EDX is separately provided as an SEM computer (SEM is controlled). To connect to a computer). That is, it is necessary to connect the SEM computer and the EDX computer by using predetermined external communication (for example, RS-232C interface). For this reason, there is a problem that the measurement result on the EDX side cannot be immediately fed back to the SEM side to control the SEM side in real time.

  This problem will be described in detail with reference to FIG. FIG. 1 is a diagram schematically showing a configuration of an electron microscope system as a comparative example.

  The comparative electron microscope system includes SEM hardware 1, SEM computer 3a, EDX hardware 2, and EDX computer 3b. The SEM computer 3 a is a computer that controls an SEM (SEM hardware) 1 based on the SEM application 42. The EDX computer 3 b is a computer that controls the EDX (EDX hardware) 2 based on the EDX application 43. The SEM computer 3a and the EDX computer 3b are connected by an external communication means 46 such as an RS-232C interface.

As for the SEM control data 44 in the electron microscope system of the comparative example, all the SEM control data 44 is always transmitted to the EDX application 43 via the SEM application 42 and the external communication means 46. Here, if the communication interval of the SEM control data 44 is shortened, the processing speeds of the SEM application 42 and the EDX application 43 are reduced. For this reason, the measurement result (dead time and X-ray detection efficiency (collection counting rate)) on the EDX hardware 2 side is fed back to the SEM computer 3a, and the communication speed sufficient to control the SEM hardware 1 in real time is obtained. There was a problem that could not be obtained.
The SEM control data 44 is data used as analysis results such as acceleration voltage and working distance, and data used for analysis control such as electron beam irradiation current adjustment values.

  Even if the SEM application 42 and the EDX application 43 are operated by a single computer, the SEM application 42 and the EDX application 43 are controlled independently, so that the measurement result on the EDX hardware 2 side is transferred to the SEM application 42. There was a problem that it took time to provide feedback.

  Therefore, the present invention solves the above-mentioned problems, feeds back the measurement results on the EDX side, controls the SEM side in real time, and provides high-precision results in sample observation and analysis without specialized knowledge and ability. It is an object of the present invention to provide an electron microscope control device and the like that can obtain the above.

In order to solve the above-described problem, the present invention is based on a measurement result output from an X-ray analyzer, a storage unit in which an electron microscope control device stores a range of a dead time target value in the X-ray analyzer, When the dead time in the X-ray analyzer is calculated, the calculated dead time is compared with the target value range of the dead time, and the calculated dead time is not within the target value range, and a control unit for creating control data for controlling the electron beam irradiation current of the microscope, the control data generated by the control unit, into a format for the control of the electron microscope, and a data sharing unit for outputting the electron microscope The data sharing unit receives the control result of the electron beam irradiation current in the electron microscope from the electron microscope, and compares the received control result with the control data output to the electron microscope. If the control results differ from control data, the control result received, configured to output to the control unit converts the format of the control unit. Other configurations will be described in an embodiment described later.

  According to the present invention, when the measurement result (dead time or X-ray detection efficiency) of the X-ray analyzer does not reach the target value, the electron microscope control device changes the electron beam irradiation current of the electron microscope accordingly. . That is, the measurement result of the X-ray analyzer is fed back in real time to control the electron beam irradiation current of the electron microscope. Therefore, even if there is no specialized knowledge and ability, it is possible to easily set the optimal analysis conditions for the sample in the X-ray analyzer. In addition, it is possible to obtain a result of observation and analysis of a sample with high accuracy. Furthermore, according to the present invention, since the operation screen and the display screen of both SEM and EDX can be displayed on the display screen of the same display device, the operability can be improved.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail below with reference to the drawings. FIG. 2 is a block diagram showing a functional development of the configuration of the electron microscope system of the present embodiment.

  The electron microscope system includes an SEM hardware 1 that is an electron microscope that irradiates a sample to be analyzed with an electron beam and measures an electron beam generated from the sample, an X-ray detector that measures X-rays generated from the sample, and The EDX hardware 2 including the energy dispersive X-ray analyzer, and the SEM hardware 1 and a computer (electron microscope control device) 3 that controls the EDX hardware 2 are configured.

  Further, a display device 9 such as a liquid crystal display and a pointing device 10 such as a keyboard and a mouse are connected to the computer 3. The display device 9 displays an SEM image of the sample output from the computer 3 and an EDX image such as an X-ray spectrum and a mapping image. The computer 3 may be provided with a storage medium reading device such as a flexible disk or an MO disk (Magneto Optical Disk) and an output device such as a printer.

The computer 3 is realized by an arithmetic processing unit including an input / output interface, a CPU (Central Processing Unit), a main memory, a storage unit, and the like.
The input / output interface controls the data input / output interface between the display device 9, the pointing device 10, the SEM hardware 1, the EDX hardware 2, and the like and the CPU. The CPU reads the SEM-EDX integrated program 4 and the data sharing object 7 (described later) stored in the storage unit onto the main memory, and controls the SEM hardware 1 and the EDX hardware 2. The main memory is, for example, a RAM (Random Access Memory), and is a storage unit used when the CPU performs arithmetic processing. The main memory stores SEM control data 8 and the like output from the SEM hardware 1. The storage unit is, for example, a hard disk device, and stores the SEM-EDX integrated program 4, the data sharing object 7, and the recipe 41 in a predetermined area. In addition, the function of the control part in a claim is implement | achieved by the execution process of the SEM-EDX integrated program 4 by CPU.

  The SEM-EDX integrated program 4 includes an SEM application 5 and an EDX application 6. The SEM application 5 is an application for the CPU to control the SEM hardware 1, and the EDX application 6 is an application for the CPU to control the EDX hardware 2. Upon receiving a command (SEM control data 8) from the computer 3, the SEM hardware 1 irradiates the sample with an electron beam based on this command. The SEM control data 8 at this time is stored in the main memory or the like by the CPU of the computer 3. Further, when receiving an instruction from the CPU of the computer 3, the EDX hardware 2 performs X-ray analysis based on the instruction. At this time, the SEM control data 8 necessary for the operation of the EDX hardware 2 is transmitted from the data sharing object 7 to the EDX application 6.

  The data sharing object 7 monitors the SEM control data 8 stored in the main memory or the like, and updates the SEM control data 71 which is the SEM control data held by itself when there is a change in the SEM control data 8. . That is, the data sharing object 7 includes SEM control data 71 and a program that monitors the SEM control data 8 and updates the SEM control data 71. Note that the function of the data sharing unit in the claims is realized by the CPU executing a program included in the data sharing object 7.

  The updated SEM control data 71 is transferred by the data sharing object 7 to the EDX application 6 (SEM-EDX integrated program 4). At this time, the data sharing object 7 converts the SEM control data 71 into a format that can be processed by the EDX application 6, and then passes it to the EDX application 6 without going through the SEM application 5. Furthermore, when the data sharing object 7 receives SEM control data from the EDX application 6, it is converted to a format that can be used for control on the SEM hardware 1 side and then output to the SEM hardware 1.

  At this time, the SEM control data 71 transferred from the data sharing object 7 to the EDX application 6 is transferred from the SEM control data 8. As a result, the amount of communication can be reduced as compared with the prior art. As a result, since the communication speed can be increased, the measurement result on the EDX side can be fed back to control the conditions on the SEM side in real time.

  In addition, the data sharing object 7 can adjust the condition on the EDX side according to the condition on the SEM side, and can adjust the condition on the SEM side according to the condition on the EDX side.

  As illustrated in Table 1, the recipe 41 includes “SEM conditions” for analyzing these samples according to the properties of the samples such as “unknown sample”, “light element sample”, and “metal sample”. The corresponding conditions are shown as “spectrum measurement conditions”, “SEM image capturing conditions”, “mapping conditions” and other “EDX conditions”.

  Next, in the electron microscope system, the observation and analysis of the sample follow the following procedure. FIG. 3 is a flowchart illustrating a sample observation and analysis procedure in the electron microscope system of FIG.

  First, the CPU of the computer 3 displays an analysis condition setting screen on the display device 9 based on the SEM-EDX integrated program 4. And the input with the information regarding the property of a sample is received via the pointing device 10. FIG. Then, the CPU selects, from the recipe 41, SEM conditions and EDX conditions suitable for the input sample properties, using the sample properties as keys. For example, if the sample is “unknown sample”, the SEM condition and EDX condition regarding “unknown sample” are selected from the recipe 41.

  Then, based on the SEM-EDX integration program 4, the CPU sets the selected SEM condition in the SEM hardware 1 and sets the EDX condition in the EDX hardware 2. Thereby, the setting of the recipe is completed (S1).

  Next, when the sample is manually set at a predetermined position of the SEM hardware 1 by the measurer (S2), the process proceeds to S3. Note that the order of the recipe setting and the sample setting may be reversed.

  When an instruction to irradiate the sample with an electron beam is input to the computer 3 via the pointing device 10, observation of the sample is started. Specifically, when an electron beam irradiation instruction is input to the computer 3, based on the SEM-EDX integrated program 4, the CPU applies the SEM hardware 1 to the sample in accordance with the SEM conditions set in S1. Instructs the start of electron beam irradiation. That is, SEM control data is output to the SEM hardware 1. In response to this, the SEM hardware 1 irradiates the sample with an electron beam (S3) so that the measurer can observe the sample.

  Note that the focus, brightness, and the like in the SEM hardware 1 are automatically adjusted by the SEM application 5. When observing and storing the SEM image, the SEM-EDX integrated program 4 stores the electron beam irradiation current adjustment value at the time of sample observation in the main memory.

  At this time, an instruction to start irradiation with an electron beam from the CPU is also output to the EDX hardware 2. That is, the X-ray generated from the sample by the electron beam irradiation to the sample is detected by the X-ray detector of the EDX hardware 2, and the sample is analyzed by the X-ray analyzer (S4).

  After sample observation, the CPU conforms to the conditions on the EDX hardware 2 side such as the dead time and the X-ray detection efficiency stored in the recipe 41 in S1 by the SEM-EDX integrated program 4 and the data sharing object 7. Thus, the SEM hardware 1 is adjusted. The adjustment of the SEM hardware 1 here is, for example, adjustment of the electron beam irradiation current value of the SEM hardware 1. Details of the adjustment procedure of the SEM hardware 1 at this time will be described later with reference to FIG.

  Here, when analyzing a plurality of parts of the sample, when the analysis is completed for one part of the sample, the process returns to S3 to observe the sample and specify the next analysis part. Then, the XDX detection and analysis are performed on the identified part by the EDX hardware 2 and the EDX application 6. At this time, the CPU performs observation and analysis after returning the value of the electron beam irradiation current in the SEM hardware 1 to the electron beam irradiation current adjustment value at the time of sample observation.

  When the analysis is completed based on the procedure of S4 described above, the CPU converts the analysis result into image data or the like by the SEM-EDX integrated program 4 and creates an analysis result report (S5). This analysis result report is output to the display device 9 or the like.

  The setting screen and operation screen, SEM image, and EDX image of the SEM hardware 1 and EDX hardware 2 described above are output to the display device 9 by the SEM-EDX integrated program 4 of the computer 3 and displayed. FIG. 4 is a screen example in the display device of FIG. As shown in FIG. 4, SEM operation menu 21, SEM setting menu 22, SEM image 23, EDX operation menu 24, EDX image (analysis result report by EDX hardware 2 and EDX application 6), EDX setting menu 25, etc. Is displayed on one screen of the display device 9. The measurer can make various settings from this screen using the pointing device 10 of FIG. 2, so that the operability can be improved.

Further, if the SEM condition or EDX condition used in the analysis is different from the recipe 41 that has already been stored, or if it is considered suitable for the subsequent analysis, this is stored as a new recipe 41 as necessary. (S6). In this case, for example, the CPU displays a selection screen as to whether or not to save the new recipe 41 on the display device 9 and saves it when a pointing instruction is input from the pointing device 10.
As described above, the computer 3 controls the SEM hardware 1 so as to be suitable for sample observation and analysis.

  Next, the adjustment procedure of the SEM hardware 1 in the analysis of the sample of S4 in FIG. 3 will be described in detail with reference to FIG. FIG. 5 is a diagram showing a procedure for adjusting SEM hardware in the analysis of the sample in S4 of FIG.

  First, based on the SEM-EDX integrated program 4, the CPU calculates the dead time of the EDX hardware 2 at a predetermined time, the X-ray detection efficiency, and the like from the measurement results of the EDX hardware 2. Then, the calculation result at this time is compared with conditions such as dead time and X-ray detection efficiency stored in the recipe 41.

Specifically, the CPU determines whether the dead time and the X-ray detection efficiency of the EDX hardware 2 are within the range of the target values of the dead time and the X-ray detection efficiency stored in the recipe 41.
In the following description, the CPU calculates the dead time of the EDX hardware 2 (S41), and determines whether this dead time is within the range of the dead time target value stored in the recipe 41 (S42). ) As an example.

Here, when the CPU determines that the dead time of the EDX hardware 2 is outside the range of the dead time target value stored in the recipe 41 (“No” in S42), the CPU determines that the dead time of the EDX hardware 2 is based on the EDX application 6. The SEM hardware 1 is controlled so that the EDX hardware 2 achieves the dead time stored in the recipe 41.
In other words, the EDX hardware 2 outputs SEM control data that is a dead time stored in the recipe 41 to the SEM hardware 1 via the data sharing object 7 (S43). The SEM control data at this time is control data for changing the value of the electron beam irradiation current in the SEM hardware 1, for example. In response to this, the SEM hardware 1 adjusts SEM conditions (mainly changing the value of the electron beam irradiation current). A method for controlling the electron beam irradiation current is, for example, adjustment of a converging lens (condenser lens). The SEM control data output by the CPU at this time is stored in the main memory as SEM control data 71 of the data sharing object 7 (S44).
On the other hand, when the dead time is within the range of the dead time target value stored in the recipe 41 (“Yes” in S42), the adjustment process of the SEM hardware 1 is terminated.

  After such adjustment, the computer 3 receives the actual control result (SEM control data 8) of the SEM hardware 1 from the SEM hardware 1 (S45). Then, the CPU stores the SEM control data 8 output from the SEM hardware 1 in the main memory (S46).

  Next, based on the data sharing object 7, the CPU compares the SEM control data 71 with the SEM control data 8 output from the SEM hardware 1 (S47). When there is a difference between the SEM control data 8 and the SEM control data 71 (“difference” in S47), the CPU rewrites the SEM control data 71 into the SEM control data 8 (S48). The rewriting at this time reads the difference between the SEM control data 71 and the SEM control data 8 from the SEM control data 71 and rewrites the information on the difference on the SEM control data 71. Then, the process returns to S41. On the other hand, when the SEM control data 71 and the SEM control data 8 are the same (“No difference” in S47), the CPU does not rewrite the SEM control data 71 and returns to S41.

  Thus, only when there is a change in the SEM control data 8, the SEM control data 71 is updated as much as the change, and the SEM control data 71 is delivered to the EDX application 6 (SEM-EDX integrated program 4). Therefore, the communication amount of SEM control data between the EDX application 6 and the SEM application 5 can be reduced. That is, the computer 3 can obtain a communication speed capable of controlling the SEM side in real time by feeding back the measurement result on the EDX side. Therefore, the computer 3 can adjust the electron beam irradiation current, which is the condition on the SEM side, so as to meet the conditions on the EDX side such as the dead time set in the recipe 41 and the X-ray detection efficiency in the analysis of the sample. it can. Therefore, even if it is not the measurement person who has a measurement technique and an adjustment technique, it can observe and analyze a sample on optimal conditions.

  In the above description, the case where it is determined whether the dead time in the EDX hardware 2 is within the range of the dead time target value stored in the recipe 41 has been described. However, the X-ray detection in the EDX hardware 2 is performed. You may make it also check efficiency. That is, whether or not the dead time is within the range of the target value of the dead time stored in the recipe 41, and the X-ray detection efficiency is within the range of the target value of the X-ray detection efficiency stored in the recipe 41. It may be determined whether or not at least one of the dead time and the X-ray detection efficiency is within the range of each target value.

  Moreover, although the dead time and the target value of the X-ray detection efficiency stored in the recipe 41 have been described as having numerical values having a certain range, that is, an upper limit value and a lower limit value, the present invention is not limited to this. That is, for example, only the upper limit value of the dead time may be set in the recipe 41, and the SEM hardware 1 may be adjusted so that the upper limit value of the dead time is 30% or less.

  In addition, since the computer 3 monitors at least one of the dead time and the X-ray detection efficiency in the EDX hardware 2 in real time and automatically adjusts the electron beam irradiation current, long-time X-ray detection is required for the sample. Even when quantitative analysis is performed, it is not necessary to measure the probe current value (current value at which the sample is actually irradiated with an electron beam) using a Faraday cup device before and after the analysis, and to correct the analysis result based on this measurement. . Therefore, the sample can be easily analyzed, and a highly accurate analysis result can be obtained.

  Furthermore, even when a sample is moved using a sample micro-adjustment device, etc., and a plurality of parts are observed and analyzed with an electron microscope, observation and analysis can be performed under optimum conditions for each of the plurality of parts of the sample. . Therefore, it is possible to reduce the labor of sample observation and analysis.

  In the above-described embodiment, the measurer who observes and analyzes the sample sets the dead time and the target value of the X-ray detection efficiency in the recipe 41 before the observation and analysis. However, the present invention is not limited to this. Not. For example, a target value (optimum value or optimum range) of the dead time and X-ray detection efficiency is set in the storage unit by default, and the computer 3 calculates the electron beam irradiation current of the SEM hardware 1 based on the default target value. You may make it adjust. In this way, the measurer can save time and effort for setting the target value in the recipe 41 each time observation and analysis are performed.

  The present invention also applies to an electron microscope system combining an SEM and a wavelength dispersive X-ray analyzer (WDX), an electron microscope system combining a transmission electron microscope (TEM) and EDX, and similar systems. Applicable.

It is the figure which showed roughly the structure of the electron microscope provided with EDX which is a comparative example. It is the block diagram which expanded and showed the structure of the structure of the electron microscope system of this Embodiment. 3 is a flowchart illustrating a sample observation and analysis procedure in the electron microscope system of FIG. 2. It is an example of the screen in the display apparatus of FIG. It is a figure which shows the adjustment procedure of SEM hardware in S4 of FIG.

Explanation of symbols

1 SEM hardware 2 EDX hardware 3 Computer (electron microscope control device)
3a SEM computer 3b EDX computer 4 SEM-EDX integrated program 5 SEM application 6 EDX application 7 data sharing object 8 SEM control data 9 display device 10 pointing device 21 SEM operation menu 22 SEM setting menu 23 SEM image 24 EDX operation menu 25 EDX setting Menu 41 Recipe 42 SEM application 43 EDX application 44 SEM control data 46 External communication means 71 SEM control data

Claims (5)

An electron microscope control apparatus for controlling an electron beam irradiation current in an electron microscope provided with an X-ray analyzer,
A storage unit for storing a range of a dead time target value in the X-ray analyzer;
Based on the measurement result output from the X-ray analyzer, the dead time in the X-ray analyzer is calculated, the calculated dead time is compared with the target value range of the dead time, and the calculated When the dead time is not a value within the range of the target value, a control unit for creating control data for controlling the electron beam irradiation current of the electron microscope,
The control data created in the previous SL controller, into a format for the control of the electron microscope, and a data sharing unit for outputting to the electronic microscope,
The data sharing unit
When the control result of the electron beam irradiation current in the electron microscope is received from the electron microscope, the received control result is compared with the control data output to the electron microscope, and the control result is different from the control data The electron microscope control apparatus , wherein the received control result is converted into a format for the control unit and output to the control unit. The storage unit stores a dead time and a target value range of X-ray detection efficiency in the X-ray analyzer,
The control unit calculates a dead time and an X-ray detection efficiency in the X-ray analyzer, compares the calculated dead time and a range of the target value of the dead time, and calculates the calculated X-ray detection efficiency and When the target value range of the X-ray detection efficiency is compared, and at least one of the calculated dead time and the calculated X-ray detection efficiency is not within the range of each target value, the electron microscope 2. The electron microscope control apparatus according to claim 1, wherein control data for controlling the electron beam irradiation current of the electron beam is generated.   The control unit creates a screen for displaying the operation screen of each of the electron microscope and the X-ray analyzer, the captured image by the electron microscope, and the analysis result by the X-ray analyzer on the same screen, The electron microscope control apparatus according to claim 1, wherein the electron microscope control apparatus outputs to a display device of the microscope control apparatus.   An electron microscope system including an electron microscope including an X-ray analyzer and the electron microscope control device according to any one of claims 1 to 3. A method for controlling an electron microscope comprising an X-ray analyzer,
A storage unit for storing a range of a dead time target value in the X-ray analyzer;
Based on the measurement result output from the X-ray analyzer, the dead time in the X-ray analyzer is calculated, the calculated dead time is compared with the target value range of the dead time, and the calculated When the dead time is not a value within the range of the target value, a control unit for creating control data for controlling the electron beam irradiation current of the electron microscope,
The control data created in the previous SL controller, into a format for the control of the electron microscope, and data sharing unit for outputting to the electronic microscope,
An electron microscope control device comprising:
By the control unit,
Based on the measurement result output from the X-ray analyzer, the dead time in the X-ray analyzer is calculated,
The calculated dead time is compared with the target value range of the dead time, and when the calculated dead time is not a value within the target value range, the electron beam irradiation current of the electron microscope Control data for controlling the output to the electron microscope via the data sharing unit,
From the electron microscope, the control result of the electron beam irradiation current in the electron microscope is received via the data sharing unit ,
By the data sharing unit,
The control result received via the control unit is compared with the control data output to the electron microscope. If the control result is different from the control data, the received control result is converted into the format for the control unit. And outputting to the control unit .