JP2000002630A - Probe moving device and sample preparing device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an application to fine operation with a superior operation property, by providing plate-shaped piezoelectric members, a strain gauge being placed between the piezoelectric members, a laminated piezoelectric member at one end of the plate-shaped piezoelectric member, and a probe at the other end. SOLUTION: In the probe-moving device used for the handling or the like of a fine sample on a semiconductor substrate, for example, a laminated piezoelectric element 101 is combined with a bimorph-type piezoelectric element 102, and the bimorph-type piezoelectric element 102 is arranged in an expansion and contraction direction 110 of the lamination-type piezoelectric element 101. The amount of displacement DZ of the bimorph-type piezoelectric element 102 is detected by a strain gauge 103, movement trace 108 of the tip of a probe is converted into the amount of correction that is linearly displaced in the same way as movement trace 109, the laminated piezoelectric element 101 is driven, and deviation DY in a circumference direction is corrected. A sample- preparing device using such probe-moving device is provided with a focusing ion beam application optical system, a deposition gas source, and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus used for handling and probing a fine sample, and in particular, for transferring a fine sample extracted from a sample substrate such as a semiconductor wafer.
The present invention relates to an apparatus suitable for grasping and probing a minute portion of a sample substrate.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No.
JP-A-5-52721, Japanese Patent Application Laid-Open
No.-155355, JP-A-6-238578 as a fine object operation device
No. 6,155,318 are known as tweezers for fine objects. Each of these is configured by using a single or a plurality of bimorph type piezoelectric elements.

[0003]

FIG. 5 shows the characteristics of the displacement of the bimorph type piezoelectric element in the conventional apparatus. In this device, the displacement in the circumferential direction around the fulcrum K of the bimorph type piezoelectric element 1 caused by the bending of the bimorph type piezoelectric element is not corrected. Thus, for example, to the tip of the probe 3 is moved in the Z direction by D _Z, the nature of the bimorph type piezoelectric element, because it involves the Y direction displacement D _Y, thereby moving besides the desired direction. For this reason, when extremely fine operations are required, such as gripping and handling of a μm-level sample and probing to a μm-level site, a moving device in a direction other than the intended movement direction must be operated. In addition, users have been required to perform complicated device operations.

[0004] An object of the present invention is to solve the above-mentioned problems and to provide a probe moving device with good operability applicable to fine operations or a sample handling device suitable for preparing and transporting a fine sample.

[0005]

An apparatus according to the present invention comprises a plate-shaped piezoelectric member, a strain gauge provided between the plate-shaped piezoelectric members, a laminated piezoelectric member at one end of the plate-shaped piezoelectric member, and the like. It is characterized by having a probe at the end.

FIG. 1 shows a probe moving device according to the present invention.
In order to solve the above-described problem, a multilayer piezoelectric element 101 and a bimorph piezoelectric element 102 are combined and configured.
The bimorph type piezoelectric element 102 is arranged in the expansion / contraction direction 110 of the multilayer piezoelectric element 101, and is driven by drivers 106 and 107, respectively. In the present invention, the structure is such that the circumferential displacement 112 caused by the bending of the bimorph piezoelectric element 102 due to the expansion and contraction of the laminated piezoelectric element 101 is corrected.

In this device, the bimorph type piezoelectric element 102
The strain gauge element 103 affixed to, to detect the displacement amount D _Z of the bimorph type piezoelectric element 102. This is A
A correction circuit 105 composed of a D converter, a ROM, a DA converter, and the like converts a movement trajectory 108 of the probe tip into a correction amount that is linearly displaced like a movement trajectory 109, and a driver 106 controls the multilayer piezoelectric element 101 driven to correct the circumferential displacement D _Y. The correction amount conversion means described above may be a control device such as a microcomputer or a personal computer. The present solution can be applied to a gripping device and micro tweezers.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIGS. FIG. 2 shows the configuration of the sample preparation apparatus of the present invention, FIG. 3 shows the configuration of the probing apparatus of the present invention, and FIG. 4 shows the configuration of microtweezers of the present invention.

<Embodiment 1> This embodiment is a sample preparation apparatus provided with a probe moving device according to the present invention.
This will be described with reference to the schematic configuration diagram shown in FIG.

[0010] The sample preparation apparatus uses a transfer means for an ion beam and a minute sample, and does not involve a manual operation requiring skill such as polishing and dicing, and does not divide the semiconductor wafer or the integrated circuit chip by cleavage or cutting. This is a device capable of producing a small sample that can be introduced into an observation device such as a transmission electron microscope) or an analyzer, and has the following structure.

A sample preparation apparatus 201 includes a focused ion beam (FIB) irradiation optical system 202 for processing and observing a sample substrate and an extracted sample, and detects secondary electrons and secondary ions emitted from the sample by the FIB irradiation. Secondary particle detector 2
03, a deposition gas source 204 for supplying a raw material gas for forming a deposition film in the FIB irradiation region, a sample stage 206 on which a sample substrate 205 such as a semiconductor wafer or a semiconductor chip is mounted, and a part of the sample substrate 205 And a holding means 208 for holding the sample holder, a holding means 208 for holding the sample holder, and a transfer means 209 for transferring the extracted sample to the sample holder. Further, a stage controller 210 for controlling the position of the sample stage 206 and a transfer unit 209
, A transfer means control device 211 for independently driving the sample stage 206, an image display means 212 for visualizing the sample holder 207, the sample substrate 205, the transfer means 209, and the like.
The FIB irradiation optical system 202 includes a FIB control device 213, a deposition gas source control device 214, a secondary particle detection control device 215, and the like, which are controlled by a calculation processing device 216.

The FIB irradiation optical system 202 transmits ions emitted from a liquid metal ion source through a beam limiting aperture, a focusing lens, and an objective lens to reduce the diameter from about 10 nm to 1 μm.
FIB 217 having a diameter of about m can be formed. Here FIB
Since the configuration of the irradiation optical system 202 does not significantly affect the present invention, a detailed description thereof will be omitted.

By scanning the FIB with a deflector over the sample substrate, the sample substrate can be processed into a shape corresponding to a scanning shape of several tens of μm to sub-μm. The processing here refers to forming a concave portion by sputtering, forming a convex portion by FIB assist deposition, or an operation of changing the shape of the sample substrate by combining these. The deposition film formed by the FIB irradiation is used to connect the probe 222 at the tip of the transfer means 209 to the sample substrate 205 and to fix the extracted sample to the sample holder 207. Further, by processing secondary electrons and secondary ions generated at the time of FIB irradiation with the secondary particle detector 203 and forming an image, a processed region or the like can be observed.

The sample stage 206 is set in a sample chamber 218, and the FIB irradiation optical system 202 and the like are also set in a vacuum vessel. The sample stage 206 includes a sample holder 207
The holding means (sample holder cassette) 208 on which the camera is mounted can be attached and detached.
The movement, tilt, and rotation in the Z direction are controlled.

In the sample preparation apparatus 201, the probe moving apparatus according to the present invention was used as a transfer means. Hereinafter, the transfer means will be described in detail.

The transfer means 209 is means for transferring a micro sample extracted from the sample substrate 205 by the FIB to the sample holder, and comprises a coarse moving part 220 and a fine moving part 221 in FIG. A sharpened probe 222 for picking up a minute sample is fixed. The coarse moving section 220 is a positioner that can be driven in the XYZ directions, and has a moving resolution of about 1 μm with a stroke of about 1 mm. Since the fine movement unit 221 is required to be as compact and precise as possible, a bimorph piezoelectric element 223 is used in the Z direction (the direction of the ion beam optical axis).

Since the bimorph type piezoelectric element has an advantage of having a relatively large stroke (several hundreds μm or more) as compared with other piezoelectric elements, it is not necessary to request the coarse moving section 220 to have high positional accuracy. 220 is easier to manufacture. Further, since the position control of the tip of the probe only needs to have a resolution on the order of μm, the resolution is relatively low among the piezoelectric elements, but a bimorph type piezoelectric element can be used sufficiently and can be manufactured at low cost.

In a known technique (Japanese Patent Application Laid-Open No. 5-52721), an example is known in which three bimorph type piezoelectric elements are configured to correspond to the XYZ axes as a transport means for transporting a separated sample. Since the bimorph type piezoelectric element bends with the other end fulcrum, the other end draws an arc according to the applied voltage. That is, in the movement in the XY plane, the probe at the tip of the transport means does not move linearly in one axial direction only by the operation of one bimorph type piezoelectric element. Accordingly, a fine movement section is constituted by three bimorph-type piezoelectric elements, and in order to move the tip of the probe to a desired position, the three bimorph-type piezoelectric elements must be controlled in a complicated manner. On the other hand, it is sufficient to use a three-axis driving means capable of accurately performing linear driving.
If the moving means is constituted only by a mechanism having a long stroke of 00 μm to several mm and a resolution of the order of μm, other structures such as a complicated mechanism, high cost, a secondary particle detector around a sample, a depot gas source, etc. It creates other problems, such as physical interference with objects.

However, also in this embodiment, the bimorph type piezoelectric element 223 is used as the fine movement means in the Z direction. However, if only the bimorph type piezoelectric element 223 is used as described above, the probe which comes into contact with the sample will have the Z fine movement. In such a case, a positional shift occurs in a plane other than Z, so that the probe cannot be brought into contact with a target position accurately. Therefore, by using the probe moving device of the present invention for the fine movement means in the Z direction, the bimorph type piezoelectric element 2 at the tip of the probe can be used.
23, the displacement in the plane other than Z is reduced.
And the probe can be accurately brought into contact with the target position. With such a configuration, a minute sample in a desired minute region of the sample substrate 205 can be extracted.

<Embodiment 2> This embodiment is a probe inspection apparatus for measuring electric circuit characteristics. FIG. 3 shows a probing device of the probe inspection device.

The probe inspection apparatus independently drives a plurality of sharpened probes, contacts the wires in a μm level region such as a semiconductor device, measures the electrical characteristics between the probes, and determines whether the electrical circuit is defective or defective. It is a device for inspecting. Since the wiring dimensions of recent devices are on the order of sub-μm, high precision is required for probe movement. The probe 104 has a coarse movement mechanism 301 in the XYZ axis direction and
The piezoelectric element can be finely moved by using the laminated piezoelectric elements 302 and 303 in the axial direction and the bimorph piezoelectric element 102 in the Z direction (the direction perpendicular to the circuit surface). The probe 104 is in a vacuum vessel of a scanning electron microscope or a scanning ion microscope, and a circuit such as a semiconductor device to be measured can be installed in a sample chamber.

In the probe inspection, the probe 104 is moved in parallel with the circuit surface within the same field of view while observing the circuit surface with a secondary electron image or the like, and the tip of the probe 104 is moved to a desired point to be measured. When the probe reaches the position 305, the movement of the probe is stopped and the probe is moved closer to the wiring or the electrode (Z-axis driving). At this time, if the Z-axis fine movement is driven only by the bimorph piezoelectric element, the probe 10
4, the displacement in the XY plane occurs with the movement in the Z-axis direction, and the probe 104 cannot be brought into contact with the desired wiring.

Therefore, a Z-axis fine movement mechanism of the probe is constituted by using the probe moving device according to the present invention. With this configuration, since the tip of the probe 104 moves linearly, the probe 10 can be accurately connected to the desired wiring without displacement.
4 can be brought into contact (probing), and desired electrical characteristics can be measured. The same applies to the case where the number of the probes 104 is not only one but also a plurality of them, and there is no problem in the essence of the probing apparatus according to the present invention. Further, the probe inspection apparatus may include not only one probing device but also a plurality of probing devices.

<Embodiment 3> Still another embodiment is a micro-tweezer shown in FIG. Micro tweezers are μ
A tool for picking an m-level fine object, and two bimorph-type piezoelectric elements 102 and 4 spaced apart from each other on a laminated piezoelectric element 101 mounted on an XYZ moving mechanism 401.
The microstructure is a basic structure in which the microprobes 104 and 404 are fixed to one end of each of the microprobes 03, and the distance between the tips of the microprobes is reduced by applying a voltage to both or one of the bimorph type piezoelectric elements. I picked it.

However, if the bimorph type piezoelectric element is simply composed of only the bimorph type piezoelectric element, the bimorph type piezoelectric element bends with one end as a fulcrum as described above. As the line segment connecting the tips of both microprobes moves as
It is not possible to pick up a fine object of the desired μm level.

Therefore, a micro-tweezer was constructed by applying the probe moving device according to the present invention. With this configuration, the distance between the tips of the micro-probes 104 and 404 can be controlled without displacement, so that a fine object can be pinched accurately and easily. In the present embodiment, two bimorph piezoelectric elements 102 and 403 are
However, two probe moving devices (FIG. 2) of the present invention may be mounted on the XYZ moving mechanism 401.

[0027]

According to the present invention, by correcting a circumferential displacement centered on a fulcrum of a bimorph type piezoelectric element caused by bending of the bimorph type piezoelectric element,
(1) The transfer of a fine object at the μm level, (2) the probing to a fine part at the μm level, and (3) the accurate and operable grip of the fine object at the μm level can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a probe moving device according to one embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a sample manufacturing apparatus according to one embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a probing device according to an embodiment of the present invention.

FIG. 4 is a schematic diagram showing the configuration of a micro-tweezer device according to one embodiment of the present invention.

FIG. 5 is an operation explanatory view of a conventional bimorph type piezoelectric element.

[Explanation of symbols]

101: laminated piezoelectric element, 102: bimorph piezoelectric element, 103: strain gauge element for detecting the displacement (D _Z ) of the bimorph piezoelectric element, 104: probe, 105 ...
Correction circuit, 108: movement trajectory of the probe tip before correction,
Reference numeral 109 denotes the movement trajectory of the probe tip after the correction, 110 denotes the displacement direction of the multilayer piezoelectric element, 111 denotes the displacement amount (D _Z ) of the bimorph piezoelectric element, and 112 denotes the displacement (D _Y ) to be corrected.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Satoshi Tomimatsu 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. Central Research Laboratory

Claims (4)

[Claims] 1. A probe moving device comprising: a plate-shaped piezoelectric member; a laminated piezoelectric member at one end of the plate-shaped piezoelectric member; and a probe at the other end. 2. An ion source, an irradiation optical system for irradiating a sample with an ion beam from the ion source, a plate-shaped piezoelectric member for extracting and moving a part of the sample, and the plate-shaped piezoelectric member A probe portion having a laminated piezoelectric member at one end, a probe at the other end, a gas source for supplying a gas for bonding the probe to the sample, and a sample stage for holding the sample. A sample preparation apparatus characterized by the above-mentioned. 3. The sample preparation apparatus according to claim 2, wherein said gas source is a deposition gas source. 4. The apparatus according to claim 2, wherein a sample holder for storing the extracted sample is provided on the sample stage.
Or the sample preparation device according to 3.