JP2000100360A - Working position correcting device for focused ion beam working device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce contamination of surfaces of a sample and the frequency of handling in the course of working, and perform work over a long time with reduced displacement of the working position, by providing a function for registering a specific number of marks for detecting displacement of the irradiating position of a focused ion beam and positional displacement of a stage, that may arise while the sample is worked. SOLUTION: A plurality of marks (1, 2, 3,..., n) are prepared for working position correction, and positions of these marks are stored. In the working, these marks are changed over from one to another at regular time intervals, while the position of each mark is detected, displacement of working position is calculated, the displacement of working position is reflected on the control of ion beam irradiation, and thereby the working position is corrected. The registration of the plurality of marks for working position correction and the changeover of marks used for position correction are enabled by a mark registering/control part 13 and by a mark changeover control part 14, respectively, each connected to a computer part 7. Contamination of a sample due to ion sputtering phenomenon and the frequency of handling by an operator can be thereby reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is effective for microdevices utilizing FIB, cross-section processing of new functional materials, etc., preparation of samples for transmission electron microscopy (TEM), micromachining of micromechanical parts, etc. In particular, the present invention relates to a processing method using a FIB processing apparatus for a long time.

[0002]

2. Description of the Related Art The prior art of the FIB processing position correction method is as follows.
It is described in JP-A-9-274879.

The above patent discloses a conventional FIB processing apparatus, and its basic configuration is shown in FIG. An ion source unit 1 for emitting ions, an ion beam control system 2 for accelerating, focusing, and deflecting an ion beam emitted from the ion source unit 1, a sample chamber unit for mounting and moving a sample 3, secondary electrons and secondary ions Detector for secondary particles 6, Scanning ion microscope (Sca
nning Ion Microscope (abbreviated as SIM) The CRT 8 displays an image, an image memory, an image control unit 9 including an image processing unit, and an input operation unit 10 such as a keyboard and a mouse.

An ion source 1 and an ion beam control system 2
Are connected to an ion source control unit 4 and an ion beam control unit 5 for controlling them, respectively. The ion source control unit 4 and the ion beam control unit 5 are connected to a computer unit 7 that performs overall control. Further, a mark detection unit 12 for detecting a processing position correction mark for correcting a processing position deviation in processing, a processing position deviation is calculated from a mark position detected by the mark detection unit, and information to be passed to an ion beam control unit. Is connected to the computer unit 7. Components 1, 2,
The broken lines including 3 and 6 correspond to the vacuum housing block of the FIB processing apparatus.

In this FIB processing apparatus, the processing position deviation correction is solved by the following means. First, the position of a mark registered for processing position deviation correction is detected before processing is performed, and the mark position is stored as a reference mark position. Next, the position of the registration mark is detected at a certain fixed time or at a set time during the processing, and the detected position is compared with the reference mark position to calculate a position shift of the processing position.
The beam irradiation position is corrected and controlled.

[0006]

In the above-mentioned conventional method, a SIM image of a registration mark is taken many times during processing and the position of the mark is detected. It is assumed that the deformation of can be ignored. However, under actual long-time processing, the number of times of mark detection is large, and the mark deformation due to the ion sputtering phenomenon is remarkable. A mark cannot be recognized during processing, and processing is interrupted. This is a serious problem in performing long-time machining.

In order to resume processing, an operator prepares a mark for position correction, registers the mark as a position correction mark, and performs an operation to start processing. This also implies that the sample surface is contaminated by the ion sputtering phenomenon and requires the operation of an operator.
This is a major problem when working for a long time.

The problem to be solved by the present invention is to provide a FIB processing apparatus capable of performing processing with less displacement of the processing position for a long time with less contamination of the sample surface during processing and operation during processing (monitoring of processing state). It is to provide a correction method.

[0009]

In order to solve the above-mentioned object, according to the present invention, n (where n = 1, 2, 3,...) Position correcting marks are produced and registered, and these marks are formed. A function is provided to switch the mark for position correction to a mark used for position correction at regular time intervals.

That is, n marks for processing position correction are prepared, and the position correction mark positions are stored. By performing mark position detection while switching these marks at regular time intervals during processing, calculating the processing position deviation amount, and reflecting this processing position deviation amount in the control of ion beam irradiation,
Processing position correction can be performed to perform long-time processing with a small processing position deviation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a configuration diagram of the FIB processing apparatus used in the embodiment. In the embodiment of the present invention, as compared with the conventional apparatus of FIG. 5, a detection mark registration control unit 13 for registering n detection marks, a mark switching unit for switching the n registered marks to position correction marks. 14 is connected to the computer unit 7. From these two control units,
It is possible to register a plurality of processing position correction marks and switch marks used for position correction. Thereby, the operation of the sample contamination operator due to the ion sputtering phenomenon near the desired processing position is reduced, and the processing is performed for a long time.

In this embodiment, the registration marks for detection 102,
103, 104, and 105 (5 μm × 5 μm cross marks) are processed to positions that do not include the processing area 101 before processing is performed, and are registered in the detection mark registration unit 13 as detection marks. Before executing the processing, the exact position of the registration mark in the processing setting possible area 100 is detected by supplying SIM image information near the mark position from the image control unit 9 to the mark detection unit 12, and the registration mark position is determined. Record. The exact positions of the detection registration marks 103, 104, and 105 can be determined from the positional relationship with the detection registration marks 102.

Processing is started. In order to control the start of the processing position correction at the start of this processing, a certain fixed time or
A timer for starting the processing position correction control at the set time is set. At the same time, a timer for starting the position detection mark switching control is set. The time set in the position correction mark switching control timer is a fixed time longer than the position correction control start timer or a set time. The position detection mark switching process is started by the position detection mark switching timer, and information of the position correction mark registered in the mark detection control unit 12 via the computer unit 7 is detected from the detection registration mark 102. The processing is performed so as to change to the registration mark 103 for use as a position correction mark. At this time, a position detection mark switching timer is started. Thereafter, the position correction marks registered by the position detection mark switching control activated at regular time intervals or set time intervals are sequentially switched to position correction marks, and processing is performed. It is not necessary to interrupt the processing at the time of the position correction mark switching process.

Means for switching the position detection mark is not only switching on the time axis by the timer, but also
It is also conceivable to execute the switching control of the position detection mark by judging from the number of times of detection with the position correction mark and information from the SIM image acquired for the detection.

In this embodiment, the correction mark for the processing position is also actually processed by the FIB processing apparatus to produce the position correction mark. As shown in FIG. 3, a characteristic image near the processing position is formed. It is also conceivable to register information and perform position correction using image processing.

[0017]

According to the present invention, a registration mark used for detecting a processing position shift for a long time FIB processing is damaged due to an ion sputtering phenomenon or the like, and the shape of the registration mark in the initial state is changed. Even if it is different from the above, it becomes possible without requiring the intervention of an operator, and this is effective in improving the precision of the processing position correction of the FIB processing apparatus and semi-automatic FIB processing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an FIB processing apparatus used in an embodiment of the present invention.

FIG. 2 is a plan view illustrating a processing area setting area according to the first embodiment.

FIG. 3 is a plan view illustrating a processing area setting area according to the first embodiment.

FIG. 4 is a flowchart showing an order of correcting a processing position according to the present invention.

FIG. 5 is a configuration diagram of a conventional FIB processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ion source part, 2 ... Ion beam control system, 3 ... Sample chamber part, 4 ... Ion source control part, 5 ... Ion beam control part, 6
... Secondary particle detector, 7 ... Computer part, 8 ... CRT,
9 image control unit, 10 input unit, 11 processing position correction unit, 12 mark detection unit, 13 mark registration control unit, 1
Reference numeral 4: mark switching control unit, 100: processing area settable area, 101: processing designation area, 102: detection registration mark 1, 103 ... detection registration mark 2, 104 ... detection registration mark 3, 105 ... detection registration Marks 4, 202: registered image for detection 1, 203: registered image 2 for detection.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideki Maruyama 832 Nagakubo, Horiguchi, Hitachinaka-shi, Ibaraki 2 F-term in Hitachi Measurement Engineering Co., Ltd. (reference) 5C030 AA08 AB05 5C034 DD06 DD09

Claims (3)

[Claims] An ion beam is focused and scanned on a sample,
Focused ion beam processing equipment that obtains a microscope image by detecting the intensity of secondary particles such as secondary electrons and secondary ions emitted from the sample in synchronization with scanning, and sets the processing position from the microscope image A mark for detecting a displacement of the irradiation position of the focused ion beam (FIB for short) and a stage displacement of the stage which occur during the processing of the sample, and for detecting the position displacement of the focused ion beam processing apparatus for correcting. A processing position correction device of a focused ion beam processing device having a function of registering n pieces (where n = 1, 2, 3,...). 2. The apparatus according to claim 1, wherein said focused ion beam processing apparatus has a function of processing a mark to be registered. In the focused ion beam processing apparatus, n registered marks (where n = 2, 3,...) For detecting positional deviation are added at regular time intervals to the n-th position correcting mark. 3. The processing position correction device for a focused ion beam processing device according to claim 1, further comprising a switching function.