JP3850154B2 - Scanning electron microscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scanning electron microscope having an objective lens and a sample stage, and more specifically, to provide a scanning electron microscope that is less affected by external vibration.
[0002]
[Prior art]
The configuration of the scanning electron microscope will be described with reference to FIG. In the figure, a sample stage 5 on which a sample holder 3 is provided is disposed in a vacuum chamber 1.
[0003]
The sample stage 5 is provided on the Z stage 7 that moves up and down (arrow Z direction), the tilt stage 9 that rotates about the axis O with respect to the Z stage 7, and the tilt stage 9. The Y stage 11 that moves in the vertical direction (Y direction), the X stage 13 that moves in the direction of the arrow X on the Y stage 11, and rotates about the axis O ′ on the X stage 13 so that the sample holder 3 The R stage 15 is provided.
[0004]
The sample holder 3 and the R stage 15 are attached by providing a dovetail-shaped “present” 15 a formed on the R stage 15, which can be engaged with and disengaged from the present 15 a of the R stage 15 on the lower surface of the sample holder 3. This is done by providing a "groove" 3a.
[0005]
Above the vacuum chamber 1, an electron beam generator 20 and an objective lens 21 for converging the electron beam onto the sample in the sample holder 3 are provided.
On the side of the vacuum chamber 1, a sample holder 3 is transported to the sample stage 5 using a sample exchange rod 23, or a sample for exchanging the sample holder 3 on the sample stage 5 with a sample holder having a different sample. An exchange chamber 25 is provided.
[0006]
And the vacuum chamber 1 and the electron beam generation part 20 of the said structure are provided on the vibration isolator, and are reducing the vibration from a floor.
In the scanning electron microscope having such a configuration, installation conditions are determined with respect to an external environment such as vibration and sound from the floor in order to guarantee resolution.
[0007]
That is, when vibration from the floor exceeding the allowable value that can be reduced by the vibration isolator is applied, or when the natural frequency of the vibration isolator coincides with the vibration frequency from the floor, the sample stage 5 and the electron The line generation unit 20 and the objective lens 21 cause relative displacement exceeding the resolution of the scanning electron microscope, thereby causing an image defect.
[0008]
In addition, since the acoustic vibration is directly transmitted to the vacuum chamber 1 on the vibration isolator, the electron beam generating unit 20 and the like, when the acoustic vibration exceeding the installation condition is applied, the sample stage 5 and the electron beam generating unit 20, The objective lens 21 causes a relative displacement greater than the resolution of the scanning electron microscope, thereby causing an image defect.
[0009]
However, in recent years, there have been cases where the scanning electron microscope is installed in a place that does not satisfy the installation conditions, such as a factory, a clean room, or a high floor of a building.
[0010]
When installed in a place that does not satisfy such installation conditions, the sample must be observed with a resolution lower than the guaranteed resolution.
Therefore, in order to prevent relative displacement between the sample stage 5, the electron beam generator 20, and the objective lens 21 due to external vibration, for example, in Japanese Patent Laid-Open No. 3-187143, the sample holder 3 is pressed against the objective lens 21. A scanning electron microscope is disclosed.
[0011]
[Problems to be solved by the invention]
In the scanning electron microscope configured to press the sample holder against the objective lens, since the sample holder directly hits the objective lens, there is a problem that the objective lens is damaged and the performance is impaired.
[0012]
The present invention has been made in view of the above problems, and an object thereof is to provide a scanning electron microscope that can prevent relative displacement between a sample stage and an objective lens due to external vibration and does not damage the objective lens. It is in.
[0013]
[Means for Solving the Problems]
The invention according to claim 1, which solves the above-described problem, is a scanning electron microscope having an objective lens and a sample stage for moving a sample holder forward and backward with respect to at least the objective lens, the abutted means of a lens and another member provided in the further the sample Hol da, the provided abutment means capable of contacting the object to be abutment means, thereby abutting the abutment means on said abutted means In this scanning electron microscope, relative displacement between the sample stage and the objective lens due to vibration is prevented .
[0014]
By abutting the abutment means of the sample Hol da to the abutment means of the objective lens side, the sample stage by vibration, the relative displacement between the objective lens can be prevented.
Further, the abutment means of the objective lens side contact means of the specimen Hol da abuts since a separate and the objective lens, the objective lens does not hurt.
[0015]
Here, it is desirable that the contacted means is provided so as to cover a part of the objective lens , as in the second aspect of the invention.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
(overall structure)
Initially, the principal part structure of the scanning electron microscope of this Embodiment is demonstrated using FIG.
[0017]
In the figure, a sample stage 105 on which a sample holder 103 is provided is disposed in a vacuum chamber 101.
The sample stage 105 is provided on the Z stage 107 that moves in the vertical direction (arrow Z direction), the tilt stage 109 that rotates about the axis O with respect to the Z stage 107, and the tilt stage 109. The Y stage 111 that moves in the vertical direction (Y direction), the X stage 113 that moves in the direction of the arrow X on the Y stage 111, and rotates about the axis O ′ on the X stage 113, the sample holder 103 The R stage 115 is provided.
[0018]
The sample holder 103 and the R stage 115 are attached by providing a dovetail-shaped “present” 115 a formed on the R stage 115, and “can be disengaged from the present 115 a of the R stage 115 on the lower surface of the sample holder 103. This is done by providing a "groove" 103a.
[0019]
Above the vacuum chamber 101, an electron beam generator 120 and a truncated cone-shaped objective lens 121 that converges the electron beam onto the sample in the sample holder 103 are provided.
On the side of the vacuum chamber 101, the sample holder 103 is transported to the sample stage 105 using the sample exchange rod 123, or the sample holder 103 on the sample stage 105 is replaced with a sample holder having a different sample. An exchange chamber 125 is provided.
[0020]
In the present embodiment, a flange 151 as a contacted means is provided so as to cover a part of the objective lens 121.
Further, the sample holder 103 is provided with a locking flange 171 as a contact means capable of contacting the flange 151.
[0021]
(Flange 151)
This will be described with reference to FIG. 1, (a) is a front view, (b) is a left side view in (a), and (c) is a bottom view in (a).
[0022]
In the drawing, a flange 151 includes a base 155 attached to the vacuum chamber 101 using a screw 153, a first extension 157 extending from the peripheral edge of the base 155 toward the sample stage 105, and a peripheral edge of the base 155. The second extending portion 159 that extends in the direction of the sample stage 105 and opposes the first extending portion 157 and the first and second extending portions 157 and 159 are bridged, and the tip of the objective lens 121 It is comprised from the bridge part 161 which covers a surface.
[0023]
A hole 161 a through which an electron beam emitted from the objective lens 121 passes is formed at the center of the bridging portion 161.
In the present embodiment, the shape of the flange 151 is set to a shape that does not restrict the movement of the sample stage 105 on which the sample holder 103 is provided.
[0024]
(Lock flange 171)
The description will be made with reference to FIG. 2 showing the locking flange 171. 2A is a front view, and FIG. 2B is a cross-sectional view taken along a cutting line AA-A in FIG.
[0025]
In the figure, the locking flange 171 is attached to the periphery of the opening 103 b of the sample holder 103 using screws 173.
When the Z stage 107 of the sample stage 105 is driven to the locking flange 171 and the sample holder 103 linearly moves upward (Z direction) toward the objective lens 121, the bridging portion 161 (see FIG. 1) of the flange 151 is obtained. A first protrusion 175 is provided in contact with a range B) surrounded by a two-dot chain line in (c).
[0026]
Further, when the tilt stage 109 of the sample stage 105 is driven to the locking flange 171 and the sample holder 103 rotates and moves toward the objective lens 121, the slope 161b (see FIG. 1 (a), (c)) is formed, a second protrusion 177 is formed.
[0027]
According to such a configuration, the first projection 175 or the second projection 177 of the locking flange 171 on the sample holder 103 side is brought into contact with the flange 151 on the objective lens 121 side, so that the sample due to external vibration can be obtained. Relative displacement between the stage 105 and the objective lens 121 can be prevented.
[0028]
The objective lens 121 is not damaged because the objective lens 121 side flange 151 on which the locking flange 171 on the sample holder 103 side contacts is separate from the objective lens 121.
[0029]
【The invention's effect】
According to the present invention as mentioned above, by abutting the abutment means of the sample Hol da to the abutment means of the objective lens side, the sample stage by vibration, the relative displacement between the objective lens can be prevented.
[0030]
Further, the abutment means of the objective lens side contact means of the specimen Hol da abuts since a separate and the objective lens, the objective lens does not hurt.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams illustrating a flange 151 in FIG. 3 for explaining a configuration of a main part of a scanning electron microscope according to an embodiment of the present invention. FIG. 1A is a front view, and FIG. The left side view, (c) is a bottom view in (a).
2A and 2B are diagrams illustrating a locking flange in FIG. 1, in which FIG. 2A is a front view, and FIG. 2B is a cross-sectional view taken along a cutting line AA in FIG.
FIG. 3 is a diagram for explaining a main configuration of a scanning electron microscope according to the present embodiment.
FIG. 4 is a diagram illustrating a configuration of a main part of a conventional scanning electron microscope.
[Explanation of symbols]
103 Sample holder 105 Sample stage 121 Objective lens 151 Flange (contacted means)
171 Locking flange (contact means)

Claims (2)

A scanning electron microscope having an objective lens and a sample stage for moving a sample holder at least with respect to the objective lens,
On the objective lens side, provided with a contact means separate from the objective lens,
Further to the sample Hol da, provided abutment means capable of contacting the object to be abutment means,
Accordingly , the scanning electron microscope is characterized by preventing relative displacement between the sample stage and the objective lens due to vibration by bringing the contact means into contact with the contacted means . The scanning electron microscope according to claim 1, wherein the contacted means is provided so as to cover a part of the objective lens .

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