JP7538069B2 - Objective lens, electron microscope, objective lens cleaning method, and jig - Google Patents

Description

The present invention relates to an objective lens, an electron microscope, a method for cleaning an objective lens, and a jig.

A scanning electron microscope is an electron microscope that scans a sample with an electron beam and detects secondary electrons and reflected electrons emitted from the sample to obtain an image. As described in Patent Document 1, a scanning electron microscope is equipped with a condenser lens and an objective lens.

JP 2014-63640 A

In scanning electron microscopes, foreign matter such as fine dust particles can get into the objective lens and adhere to the inside of the objective lens. If foreign matter adheres to the objective lens, it can cause discharge, static electricity, and astigmatism. For this reason, cleaning is required to remove foreign matter from inside the objective lens.

However, an electrode or orifice may be placed at the tip of the objective lens. The holes formed in the electrode or orifice to allow the electron beam to pass through have a small diameter. This makes it difficult to clean the inside of the objective lens.

One aspect of the objective lens according to the present invention is
An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
A pole piece having a diameter larger than that of the shaft portion is fixed to the electrode,
the fitting hole is an opening at a tip end of the outer yoke,
the pole piece has an abutment surface that abuts against a tip of the outer yoke when the shaft portion is fitted into the fitting hole,
The coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.
One aspect of the objective lens according to the present invention is
An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
A flange portion having a diameter larger than that of the shaft portion;
Including,
The fitting hole is provided in the holding portion,
the flange portion has an abutment surface that abuts against a surface of the holding portion when the shaft portion is fitted into the fitting hole,
The coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.
One aspect of the objective lens according to the present invention is
An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A nut portion that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A threaded portion held by the nut portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The screw portion is located at a tip of the electrode,
the screw portion and the nut portion are screwed together with some backlash to hold the electrode, and the coaxiality between the electrode and the objective lens body is not restricted,
The threaded portion is screwed into the nut portion, so that the shaft portion is fitted into the engagement hole,
The coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.

In such an objective lens, the electrode located at the tip of the inner yoke is removable, so that the electrode can be removed when cleaning the objective lens, and foreign matter inside the inner yoke can be easily removed.

One aspect of the objective lens according to the present invention is
An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
A pole piece having a diameter larger than that of the shaft portion is fixed to the orifice,
the fitting hole is an opening at a tip end of the outer yoke,
the pole piece has an abutment surface that abuts against a tip of the outer yoke when the shaft portion is fitted into the fitting hole,
The concentricity between the orifice and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.
One aspect of the objective lens according to the present invention is
An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
A flange portion having a diameter larger than that of the shaft portion;
Including,
The fitting hole is provided in the holding portion,
the flange portion has an abutment surface that abuts against a surface of the holding portion when the shaft portion is fitted into the fitting hole,
The concentricity between the orifice and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.
One aspect of the objective lens according to the present invention is
An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A nut portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A threaded portion held by the nut portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
the threaded portion is located at a tip of the orifice,
the screw portion and the nut portion are screwed together with some backlash to hold the electrode, and the coaxiality between the electrode and the objective lens body is not restricted,
The threaded portion is screwed into the nut portion, so that the shaft portion is fitted into the engagement hole,
The concentricity between the orifice and the objective lens body is regulated by the fit between the fitting hole and the shaft portion.

In such an objective lens, the orifice located at the tip of the inner yoke is removable, so that the orifice can be removed when cleaning the objective lens, and foreign matter inside the inner yoke can be easily removed.

One aspect of the electron microscope according to the present invention is
The objective lens is included.

In such an electron microscope, the objective lens is easy to clean because it includes the objective lens described above.

One aspect of the objective lens cleaning method according to the present invention includes the steps of:
A method for cleaning an objective lens of an electron microscope, comprising the steps of:
Removing an electrode disposed at a tip of an inner yoke of the objective lens;
cleaning the inside of the inner yoke;
Including,
The objective lens includes an objective lens body;
The objective lens body includes:
Outer yoke and
The inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The fitting of the fitting hole and the shaft portion regulates the coaxiality of the electrode and the objective lens body,
a step of fixing a cleaning tool to a jig having a fitting portion that fits into the fitting hole;
a step of fitting the fitting portion into the fitting hole to introduce the cleaning tool into the inner yoke;
and moving the jig to clean the inside of the inner yoke with the cleaning tool .

This method of cleaning the objective lens includes a step of removing the electrode located at the tip of the inner yoke, making it easy to remove foreign matter from inside the inner yoke.

One aspect of the objective lens cleaning method according to the present invention includes the steps of:
A method for cleaning an objective lens of an electron microscope, comprising the steps of:
Removing an orifice disposed at a tip of an inner yoke of the objective lens;
cleaning the inside of the inner yoke;
Including,
The objective lens includes an objective lens body;
The objective lens body includes:
Outer yoke and
The inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The concentricity between the orifice and the objective lens body is regulated by the fit between the fitting hole and the shaft portion,
a step of fixing a cleaning tool to a jig having a fitting portion that fits into the fitting hole;
a step of fitting the fitting portion into the fitting hole to introduce the cleaning tool into the inner yoke;
and moving the jig to clean the inside of the inner yoke with the cleaning tool .

This method of cleaning the objective lens includes a step of removing the orifice located at the tip of the inner yoke, making it easy to remove foreign matter from inside the inner yoke.

One aspect of the jig according to the present invention is
A jig for fixing a cleaning tool used for cleaning an objective lens of an electron microscope,
a fitting portion that is fitted into a fitting hole of the objective lens;
A fixing part for fixing the cleaning tool;
Including,
The cleaning tool fixed to the fixing part is introduced into the objective lens by fitting the fitting part into the fitting hole.

This type of jig has a fitting portion that fits into the fitting hole of the objective lens, so the cleaning tool can be introduced into the appropriate position inside the objective lens. This makes it easy to clean the inside of the objective lens.

FIG. 1 is a diagram showing the configuration of a scanning electron microscope equipped with an objective lens according to a first embodiment. FIG. 1 is a cross-sectional view illustrating an objective lens according to a first embodiment. FIG. 1 is a cross-sectional view illustrating an objective lens according to a first embodiment. 5 is a flowchart showing an example of a cleaning method for an objective lens according to the first embodiment. FIG. 11 is a cross-sectional view illustrating an objective lens according to a first modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a first modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second modified example. FIG. 13 is a diagram showing the configuration of a scanning electron microscope equipped with an objective lens according to a second embodiment. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second embodiment. FIG. 11 is a cross-sectional view illustrating an objective lens according to a second embodiment. FIG. 11 is a cross-sectional view illustrating an objective lens according to a first modified example. FIG. 11 is a cross-sectional view illustrating an objective lens according to a first modified example. FIG. 13 is a cross-sectional view illustrating a jig according to a third embodiment. FIG. 13 is a plan view showing a jig according to a third embodiment. FIG. 11 is a cross-sectional view showing a schematic diagram of a state in which foreign matter is removed from within the inner yoke of the objective lens by a cleaning tool. FIG. 11 is a cross-sectional view showing a schematic diagram of a state in which foreign matter is removed from within the inner yoke of the objective lens by a cleaning tool. FIG. 11 is a cross-sectional view showing a schematic diagram of a state in which foreign matter is removed from within the inner yoke of the objective lens by a cleaning tool. FIG. 11 is a diagram for explaining a jig according to a second modified example.

Below, preferred embodiments of the present invention are described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

1. First embodiment 1.1 Electron microscope First, an electron microscope equipped with an objective lens according to the first embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing the configuration of a scanning electron microscope 10 equipped with an objective lens according to the first embodiment.

The scanning electron microscope 10 is an electron microscope that scans a sample S with an electron beam EB and detects secondary electrons and reflected electrons emitted from the sample S to obtain an image. As shown in Fig. 1, the scanning electron microscope 10 is equipped with an objective lens 100. The scanning electron microscope 10 includes an electron source 11, a condenser lens 12, a scanning deflector 13, a sample stage 14, an electron detector 15, and the objective lens 100.

The electron source 11 generates electrons. The electron source 11 is, for example, an electron gun that accelerates electrons emitted from a cathode at an anode and emits an electron beam EB.

The condenser lens 12 focuses the electron beam EB emitted from the electron source 11. The condenser lens 12 can control the diameter and current of the electron beam EB.

The objective lens 100 is placed just before the sample S housed in the sample chamber. The objective lens 100 focuses the electron beam EB. By focusing the electron beam EB with the objective lens 100 and the condenser lens 12, an electron probe can be formed.

The scanning deflector 13 deflects the electron beam EB two-dimensionally. The scanning deflector 13 is used to scan the sample S with the electron beam EB.

The sample S is placed on the sample stage 14. The sample stage 14 is capable of holding the sample S. The sample stage 14 has a movement mechanism for moving the sample S. By moving the sample S on the sample stage 14, the position on the sample S where the electron beam EB is irradiated can be moved.

The electron detector 15 is a secondary electron detector that detects secondary electrons emitted from the sample S when the sample S is irradiated with the electron beam EB. The electron detector 15 may be a backscattered electron detector that detects backscattered electrons emitted from the sample S when the sample S is irradiated with the electron beam EB. The scanning electron microscope 10 may be equipped with both a secondary electron detector and a backscattered electron detector.

2 and 3 are cross-sectional views that show the objective lens 100 according to the first embodiment. Note that Fig. 2 shows a state in which the electric field ring 150 is attached to the objective lens body 2, and Fig. 3 shows a state in which the electric field ring 150 is detached from the objective lens body 2.

2 and 3, the objective lens 100 includes an objective lens body 2 and an electric field ring 150 (an example of an electrode). The objective lens body 2 includes an outer yoke 110, an inner yoke 120, a pole piece 130, an acceleration/deceleration electrode 140, and a nut 160 (an example of a holding portion).

The outer yoke 110 and the inner yoke 120 create a path for the magnetic lines of force. The inner yoke 120 is disposed within the outer yoke 110. A coil (not shown) is disposed in the gap between the outer yoke 110 and the inner yoke 120. The outer yoke 110 and the inner yoke 120 guide the magnetic lines of force created by the coil to the pole piece 130.

The pole piece 130 is fixed to the electric field ring 150. The pole piece 130 leaks the magnetic field lines created by the coil into space. This creates a strong magnetic field on the optical axis of the objective lens 100.

The acceleration/deceleration electrode 140 is disposed within the inner yoke 120. The acceleration/deceleration electrode 140 is cylindrical, and the electron beam EB passes through the inside. A high voltage is applied to the acceleration/deceleration electrode 140. When a high voltage is applied to the acceleration/deceleration electrode 140, an electric field lens is formed between the acceleration/deceleration electrode 140 and the electric field ring 150. This electric field lens makes it possible to accelerate or decelerate the electron beam EB.

The electric field ring 150 is disposed at the tip of the objective lens body 2. Specifically, the electric field ring 150 is disposed at the tip of the outer yoke 110 and the tip of the inner yoke 120.

The electric field ring 150 forms an electrostatic lens between the acceleration/deceleration electrode 140 and the electric field ring 150 to accelerate or decelerate the electron beam EB. In other words, the electric field ring 150 functions as an electrode for forming an electrostatic lens. The electric field ring 150 is at, for example, ground potential.

The electric field ring 150 is cylindrical. The electron beam EB passes through the electric field ring 150. The magnetic pole piece 130 is fixed to the lower end of the electric field ring 150. A threaded portion 152 (an example of a held portion) is provided at the upper end of the electric field ring 150. A male thread formed on the outer surface of the tip of the electric field ring 150 constitutes the threaded portion 152. The electric field ring 150 is detachable from the objective lens body 2.

The nut 160 holds the electric field ring 150. Specifically, the electric field ring 150 is fixed to the nut 160 by screwing the threaded portion 152 provided on the nut 160 and the electric field ring 150 together. The nut 160 is cylindrical, and has an internal thread 162 formed on its inner surface. The nut 160 is fixed to the outer yoke 110. The tip of the inner yoke 120 is located inside the nut 160.

Although not shown, the nut 160 may be fixed to the inner yoke 120. Although not shown, a female thread may be formed on the inner surface of the outer yoke 110. In other words, the outer yoke 110 may be provided with a holding portion for holding the electric field ring 150.

The electric field ring 150 is held in place by screwing the threaded portion 152 of the electric field ring 150 into the nut 160. Because the electric field ring 150 is held in place by the threaded portion 152 and the nut 160, the electric field ring 150 is detachable from the objective lens body 2.

A shaft portion 154 is provided below the threaded portion 152 of the field ring 150. The shaft portion 154 is provided between the threaded portion 152 and the pole piece 130. The shaft portion 154 is cylindrical. The diameter of the shaft portion 154 is larger than the diameter of the threaded portion 152.

When the electric field ring 150 is inserted into the opening 112 (an example of a fitting hole) at the tip of the outer yoke 110 and the threaded portion 152 of the electric field ring 150 is screwed into the nut 160, the shaft portion 154 fits into the opening 112 of the outer yoke 110. This ensures coaxiality between the objective lens body 2 and the electric field ring 150. Specifically, the coaxiality between the outer yoke 110 and the electric field ring 150 is ensured.

In this way, in the objective lens 100, the coaxiality of the electric field ring 150 and the outer yoke 110 (objective lens body 2) is regulated by the fit of the opening 112 of the outer yoke 110 and the shaft portion 154. Note that the coaxiality of the electric field ring 150 and the outer yoke 110 refers to the degree of misalignment between the axis of the electric field ring 150 and the axis of the outer yoke 110.

In the objective lens 100, as described above, the coaxiality of the field ring 150 and the outer yoke 110 is regulated by the fit of the opening 112 of the outer yoke 110 and the shaft portion 154. Therefore, the threaded portion 152 and the nut 160 have a loose pitch and a loose hook, and the backlash as a screw is increased. As a result, the threaded portion 152 and the nut 160 have a function of holding the field ring 150, but do not have a function of regulating the coaxiality. Thus, in the objective lens 100, the threaded portion 152 and the nut 160 do not contribute to regulating the coaxiality of the field ring 150 and the outer yoke 110.

When the electric field ring 150 is inserted into the opening 112 at the tip of the outer yoke 110 and the threaded portion 152 of the electric field ring 150 is screwed into the nut 160, the upper surface 132 of the pole piece 130 fixed to the electric field ring 150 abuts against the surface 114 at the tip of the outer yoke 110. This prevents the electric field ring 150 from tilting relative to the outer yoke 110. In other words, the upper surface 132 of the pole piece 130 functions as an abutment surface to regulate the vertical deviation of the electric field ring 150.

1.3. Objective Lens Cleaning Method FIG. 4 is a flowchart showing an example of a method for cleaning the objective lens 100.

First, the scanning electron microscope 10 is opened to the atmosphere. Then, the electric field ring 150 arranged at the tip of the inner yoke 120 is removed (S100). Specifically, the electric field ring 150 is removed from the objective lens body 2 by loosening the screw portion 152. This allows the electric field ring 150 to be removed from the tip of the inner yoke 120.

Next, foreign objects within the inner yoke 120 are removed (S102). Foreign objects within the inner yoke 120 can be removed using, for example, a cotton swab. Here, foreign objects within the acceleration/deceleration electrode 140 arranged within the inner yoke 120 are removed.

Next, the electric field ring 150 is attached to the objective lens body 2 (S104). The electric field ring 150 is attached so that the axis of the electric field ring 150 coincides with the axis of the outer yoke 110.

Specifically, the electric field ring 150 is inserted into the opening 112 at the tip of the outer yoke 110, and the threaded portion 152 of the electric field ring 150 is screwed into the nut 160. This causes the nut 160 and the threaded portion 152 to screw together and hold the electric field ring 150 in place, while the fit between the opening 112 of the outer yoke 110 and the shaft portion 154 regulates the concentricity of the electric field ring 150 and the outer yoke 110. The scanning electron microscope 10 is then evacuated to a vacuum.

The above steps allow the objective lens 100 to be cleaned.

1.4 Effects and Effects The objective lens 100 includes an objective lens body 2 and an electric field ring 150 that is detachable from the objective lens body 2. The objective lens body 2 also includes an outer yoke 110, an inner yoke 120, and a nut 160 that detachably holds the electric field ring 150. The electric field ring 150 also includes a threaded portion 152 that is held by the nut 160, and a shaft portion 154 that is fitted into an opening 112 provided in the outer yoke 110, and the concentricity of the electric field ring 150 and the objective lens body 2 (outer yoke 110) is regulated by the fit of the opening 112 and the shaft portion 154.

In this way, in the objective lens 100, the nut 160 and the threaded portion 152 make the electric field ring 150 detachable, and the fit of the opening 112 and the shaft portion 154 regulates the coaxiality of the electric field ring 150 and the outer yoke 110. In the objective lens 100, the electric field ring 150 arranged at the tip of the inner yoke 120 is detachable, so that the electric field ring 150 can be removed when cleaning the objective lens 100. This makes it easy to remove foreign matter adhering to the inside of the inner yoke 120.

Here, fitting allows for smaller coaxiality than screws and nuts. Therefore, in the objective lens 100, the coaxiality between the electric field ring 150 and the outer yoke 110 can be reduced while the electric field ring 150 is removable. Therefore, when attaching the electric field ring 150 removed for cleaning to the objective lens body 2, the coaxiality between the electric field ring 150 and the outer yoke 110 can be easily reduced. For example, the axis of the electric field ring 150 and the axis of the outer yoke 110 can be aligned.

In the objective lens 100, the fitting hole into which the shaft portion 154 fits is the opening 112 of the outer yoke 110. Therefore, in the objective lens 100, the coaxiality between the electric field ring 150 and the outer yoke 110 can be reduced.

The objective lens 100 includes an acceleration/deceleration electrode 140 disposed within the inner yoke 120. As described above, the electric field ring 150 of the objective lens 100 can be removed, so that foreign matter adhering to the acceleration/deceleration electrode 140 can be easily removed.

Since the scanning electron microscope 10 includes an objective lens 100, cleaning of the objective lens 100 can be easily performed.

The cleaning method for the objective lens 100 includes a step of removing the electric field ring 150 arranged at the tip of the inner yoke 120 of the objective lens 100, and a step of cleaning the inside of the inner yoke 120. Since this cleaning method includes a step of removing the electric field ring 150, cleaning of the inside of the inner yoke 120 can be easily performed.

5 and 6 are cross-sectional views that show a schematic diagram of the objective lens 101 according to the first modified example. Note that Fig. 5 shows a state in which the orifice 151 is attached to the objective lens body 2, and Fig. 6 shows a state in which the orifice 151 is detached from the objective lens body 2.

In the following, in the objective lens 101 according to the first modified example, components having the same functions as the components of the objective lens 100 described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

In the objective lens 100 described above, as shown in Figures 2 and 3, the electric field ring 150 was detachable from the objective lens body 2.

In contrast, in the objective lens 101, as shown in Figures 5 and 6, the orifice 151 is detachable from the objective lens body 2. Below, the objective lens 101 will be described in terms of the differences from the objective lens 100, and a description of the similarities will be omitted.

The orifice 151 has a hole 156. The hole 156 allows the electron beam EB to pass through and creates a pressure difference between the inside of the objective lens 101 and the outside of the objective lens 101 (the sample chamber). For example, the orifice 151 can maintain a high vacuum inside the objective lens 101 while creating a low vacuum in the sample chamber. This allows the sample S to be observed in a low vacuum state.

In addition, the orifice 151 may function as an electrode that forms an electric field lens together with the acceleration/deceleration electrode 140.

The objective lens 101 includes an objective lens body 2 and an orifice 151 that is detachable from the objective lens body 2. The orifice 151 also has a threaded portion 152 and a shaft portion 154, and the concentricity of the orifice 151 and the outer yoke 110 is regulated by the fit of the opening 112 of the outer yoke 110 and the shaft portion 154.

Therefore, in the objective lens 101, like the objective lens 100, the orifice 151 can be removed when cleaning the objective lens 101. This makes it easy to remove foreign matter adhering to the inside of the inner yoke 120. Furthermore, in the objective lens 101, like the objective lens 100, the coaxiality between the orifice 151 and the outer yoke 110 can be easily reduced when attaching the orifice 151 removed during cleaning to the objective lens body 2.

In addition, in the scanning electron microscope 10 shown in FIG. 1, the electric field ring 150 of the objective lens 100 may be replaced with an orifice 151.

7 to 9 are cross-sectional views that show a schematic diagram of an objective lens 102 according to a second modified example. Note that Fig. 7 shows a state in which the electric field ring 150 is attached to the objective lens body 2, and Fig. 8 shows a state in which the electric field ring 150 is detached from the objective lens body 2. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 7.

In the following, in the objective lens 102 according to the second modified example, components having the same functions as the components of the objective lens 100 described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

In the above-described objective lens 100, as shown in Figures 2 and 3, the electric field ring 150 was detachable from the objective lens body 2 by the nut 160 and the threaded portion 152. That is, the nut 160 functioned as the holding portion, and the threaded portion 152 functioned as the held portion.

In contrast, in the objective lens 102, as shown in Figures 7 to 9, the electric field ring 150 can be attached and detached to the objective lens body 2 by a ball 172 fixed to the support ring 170 and a recess 153 provided in the electric field ring 150.

The support ring 170 is fixed to the outer yoke 110. Although not shown, the support ring 170 may be fixed to the inner yoke 120. As shown in FIG. 9, four balls 172 are fixed to the support ring 170. The four balls 172 are arranged at equal intervals (90° intervals) from one another. The number of balls 172 is not particularly limited as long as it can hold the electric field ring 150. The electric field ring 150 has four recesses 153 corresponding to the four balls 172.

When the electric field ring 150 is inserted into the opening 112 at the tip of the outer yoke 110, the four balls 172 fit into the recesses 153. This holds the electric field ring 150 in place. At this time, the shaft 154 fits into the opening 112 of the outer yoke 110. This ensures concentricity between the outer yoke 110 and the electric field ring 150.

As shown in Figures 10 and 11, the electric field ring 150 may be held by fitting an elastic body 173, such as a circular spring or a circular rubber, fixed to the support ring 170 into a groove 155 formed on the outer surface of the electric field ring 150. The elastic body 173 and the groove 155 make the electric field ring 150 detachable.

2. Second embodiment 2.1. Electron microscope Next, an electron microscope equipped with an objective lens according to the second embodiment will be described with reference to the drawings. Fig. 12 is a diagram showing the configuration of a scanning electron microscope 20 equipped with an objective lens according to the second embodiment. Hereinafter, in the scanning electron microscope 20, components having the same functions as those of the scanning electron microscope 10 shown in Fig. 1 described above will be given the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 12, the scanning electron microscope 20 is equipped with an objective lens 200. The objective lens 200 is a so-called semi-in-lens type objective lens. In the objective lens 200, secondary electrons emitted from the sample S are sucked up into the lens by the leakage magnetic field of the objective lens 200, and are further guided upward along the optical axis while being constrained by the magnetic field of the objective lens 200. Therefore, the electron detector 15 is disposed above the objective lens 200 in order to efficiently detect the secondary electrons.

2.2 Objective Lens Figures 13 and 14 are cross-sectional views that show a schematic diagram of the objective lens 200 according to the second embodiment. Note that Figure 13 shows a state in which the tip electrode 230 is attached to the objective lens body 2, and Figure 14 shows a state in which the tip electrode 230 is detached from the objective lens body 2.

As shown in Figures 13 and 14, the objective lens 200 includes an objective lens body 2 and a tip electrode 230 (an example of an electrode). The objective lens body 2 includes an outer yoke 210, an inner yoke 220, a nut 240 (an example of a holding portion), and an insulating member 250.

The outer yoke 210 and the inner yoke 220 have the same configuration and function as the outer yoke 110 and the inner yoke 120 described above.

The tip electrode 230 is disposed at the tip of the objective lens body 2. Specifically, the tip electrode 230 is disposed at the tip of the inner yoke 120. The tip electrode 230 is an electrode for attracting electrons into the objective lens 200 or for repelling electrons. The tip electrode 230 is cylindrical, and the electron beam EB passes through the tip electrode 230. A predetermined voltage is applied to the tip electrode 230.

The upper end of the tip electrode 230 is provided with a threaded portion 232 (an example of a held portion). In addition, a shaft portion 234 is provided below the threaded portion 232 of the tip electrode 230. The shaft portion 234 is provided between the threaded portion 232 and the flange portion 238. The shaft portion 234 is cylindrical. The diameter of the shaft portion 234 is larger than the diameter of the threaded portion 232. An abutment surface 236 is provided below the shaft portion 234. The abutment surface 236 is the upper surface of the flange portion 238, and the diameter of the flange portion 238 is larger than the diameter of the shaft portion 234. The tip electrode 230 is detachable from the nut 240.

The nut 240 holds the tip electrode 230. Specifically, the tip electrode 230 is fixed to the nut 240 by screwing the threaded portion 232 provided on the nut 240 and the tip electrode 230 together. The nut 240 is cylindrical and has an internal thread 242 formed on its inner surface.

The nut 240 has a fitting hole 244. The fitting hole 244 is a hole defined by the inner surface of the nut 240 and is located below the portion where the female thread 242 is provided.

The nut 240 is fixed to a base flange 276 by a fixing screw 274 via an insulating ring 270 and an insulating bush 272. The insulating ring 270 and the insulating bush 272 electrically isolate the tip electrode 230 from the base flange 276.
A voltage is applied via terminal 280 and wire 282. When a voltage is applied to nut 240, a voltage is applied to tip electrode 230 attached to nut 240.

An insulating member 250 is disposed between the nut 240 and the outer yoke 210. The insulating member 250 provides electrical insulation between the nut 240 and the outer yoke 210. The insulating member 250 is, for example, an O-ring, and provides an airtight seal between the nut 240 and the outer yoke 210.

When the threaded portion 232 of the tip electrode 230 is screwed into the nut 240, the shaft portion 234 fits into the fitting hole 244 of the nut 240. This ensures the coaxiality of the inner yoke 220 and the tip electrode 230. In this way, in the objective lens 200, the fitting of the fitting hole 244 of the nut 240 and the shaft portion 234 regulates the coaxiality of the tip electrode 230 and the objective lens body 2. Specifically, the coaxiality of the tip electrode 230 and the inner yoke 220 is regulated.

In the objective lens 200, similar to the objective lens 100, the threaded portion 232 and the nut 240 have a loose pitch and a loose grip, which increases the play of the screw. As a result, the threaded portion 232 and the nut 240 have the function of holding the tip electrode 230, but do not have the function of regulating the coaxiality. Thus, in the objective lens 200, the threaded portion 232 and the nut 240 do not contribute to regulating the coaxiality of the tip electrode 230 and the inner yoke 220.

When the threaded portion 232 of the tip electrode 230 is screwed into the nut 240, the abutment surface 236 of the tip electrode 230 abuts against the tip surface 246 of the nut 240. This prevents the tip electrode 230 from tilting relative to the inner yoke 220. In other words, the abutment surface 236 regulates the vertical displacement of the field ring 150.

2.3. Objective Lens Cleaning Method The cleaning method for the objective lens 200 is similar to the above-mentioned cleaning method for the objective lens 100, and therefore a description thereof will be omitted.

2.4. Effects and Effects As with the objective lens 100, the objective lens 200 allows the tip electrode 230 to be detached by the nut 240 and the threaded portion 232, and the coaxiality between the tip electrode 230 and the inner yoke 220 is regulated by the fit between the fitting hole 244 and the shaft portion 234. Therefore, as with the objective lens 100, the tip electrode 230 can be removed during cleaning in the objective lens 200. This makes it easy to remove foreign matter adhering to the inside of the inner yoke 220. As with the objective lens 100, the objective lens 200 also allows the coaxiality between the tip electrode 230 and the inner yoke 220 to be easily reduced.

In the objective lens 200, a fitting hole 244 is provided in the nut 240. The nut 240 is also disposed within the outer yoke 210, and an insulating member 250 is disposed between the nut 240 and the outer yoke 210. Therefore, in the objective lens 200, the tip electrode 230 and the outer yoke 210 can be electrically isolated.

In addition, in the objective lens 200, the insulating member 250 is an O-ring that hermetically seals the space between the outer yoke 210 and the nut 240. Therefore, in the objective lens 200, a pressure difference can be created between the inside and outside of the objective lens 200.

In the objective lens 200, the inner yoke 220 and the tip electrode 230 are spaced apart. This allows the inner yoke 220 and the tip electrode 230 to be electrically independent.

2.5. Modifications 2.5.1. First Modification Figures 15 and 16 are cross-sectional views that show a schematic diagram of an objective lens 201 according to a first modification. Note that Figure 15 shows a state in which an orifice 231 is attached to an objective lens body 2, and Figure 16 shows a state in which the orifice 231 is detached from the objective lens body 2.

Hereinafter, in the objective lens 201 according to the first modified example, components having the same functions as the components of the objective lens 101 and the objective lens 200 described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

In the objective lens 200 described above, as shown in Figures 13 and 14, the tip electrode 230 was detachable from the objective lens body 2.

In contrast, in the objective lens 201, as shown in Figures 15 and 16, the orifice 151 is detachable from the objective lens body 2. The orifice 231 has a hole 235. The hole 235 allows the electron beam EB to pass through and creates a pressure difference between the inside of the objective lens 201 and the outside of the objective lens 201 (the sample chamber). The rest of the configuration of the objective lens 201 is the same as that of the objective lens 200, and a description thereof will be omitted.

In the objective lens 201, like the objective lens 200, the orifice 231 can be removed when cleaning the objective lens 201. This makes it easy to remove foreign matter adhering to the inside of the inner yoke 220. Furthermore, in the objective lens 201, like the objective lens 200, the coaxiality between the orifice 231 and the inner yoke 220 can be easily reduced when attaching the orifice 231 removed for cleaning to the objective lens body 2.

In addition, in the scanning electron microscope 20 shown in FIG. 12, the tip electrode 230 of the objective lens 200 may be replaced with an orifice 231.

13 and 14, in the objective lens 200 described above, the tip electrode 230 is detachable from the objective lens body 2 by the nut 240 and the threaded portion 232, but the method for making the tip electrode 230 detachable is not limited to this. For example, the tip electrode 230 may be made detachable by a method similar to that described in "1.5.2. Second Modification" above.

3. Third embodiment 3.1. Jig Next, a jig according to a third embodiment will be described with reference to the drawings. Fig. 17 is a cross-sectional view that shows a jig 300 according to the third embodiment. Fig. 18 is a plan view that shows a jig 300 according to the third embodiment. Fig. 17 is a cross-sectional view taken along line XVII-XVII in Fig. 18.

The jig 300 is a jig for holding a cleaning tool 301 used to clean the objective lens 100 of the scanning electron microscope 10 shown in Figures 2 and 3 described above. By using the jig 300, foreign matter within the inner yoke 140 can be easily removed in step S102 of removing foreign matter within the inner yoke 140 shown in Figure 4 described above.

As shown in Figures 17 and 18, the jig 300 includes a housing 310 having a fitting portion 312 and a fixing portion 320 for fixing the cleaning tool 301.

The housing 310 houses the fixed part 320. The housing 310 is cylindrical and houses the fixed part 320 inside.

The tip of the housing 310 is provided with a fitting portion 312 that fits into the opening 112 of the outer yoke 110. The fitting portion 312 is cylindrical and has a smaller diameter than the other parts of the housing 310. A step is formed at the boundary between the fitting portion 312 and the other parts of the housing 310, and this step forms the top surface 311. The top surface 311 of the housing 310 functions as a stop surface to regulate the vertical deviation of the jig 300, as described below.

The housing 310 is made of, for example, a material that is softer than the outer yoke 110 of the objective lens 100. The material of the housing 310 is, for example, a resin such as acrylic resin or PEEK (polyether ether ketone resin). Also, if the material of the outer yoke 110 is iron, the housing 310 may be made of a metal that is softer than iron, such as aluminum or copper.

The fixing part 320 is a member for fixing the cleaning tool 301. The cleaning tool 301 is, for example, a cotton swab or a brush. The fixing part 320 is housed in the housing 310. The fixing part 320 is, for example, cylindrical. The upper surface of the fixing part 320 is provided with holes 322 for fixing the cleaning tool 301. In the illustrated example, the fixing part 320 is provided with four holes 322. Two of the four holes 322 are for fixing the cleaning tool 301 introduced inside the acceleration/deceleration electrode 140, and the other two holes 322 are for fixing the cleaning tool 301 introduced outside the acceleration/deceleration electrode 140. The two holes 322 are arranged on a first virtual circle, and the other two holes 322 are arranged on a second virtual circle having a diameter larger than that of the first virtual circle. The first virtual circle and the second virtual circle are concentric circles with their centers at the same position.

A cleaning tool 301 is inserted into each of the four holes 322 of the fixing part 320. In other words, four cleaning tools 301 are fixed to the fixing part 320. Note that the number of cleaning tools 301 fixed to the fixing part 320 is not particularly limited.

A long hole 314 is provided on the side of the housing 310. The fixing part 320 is fixed to the housing 310 by a fixing screw 330 that passes through the long hole 314. The long hole 314 is a hole that extends in the vertical direction (height direction), and the position at which the fixing part 320 is fixed can be changed. By changing the position at which the fixing part 320 is fixed, the height of the cleaning tool 301 can be adjusted.

3.2. Objective Lens Cleaning Method The cleaning method for objective lens 100 is as described above in “1.3. Objective Lens Cleaning Method”, and includes step S100 of removing electric field ring 150 arranged at the tip of inner yoke 120, step S102 of removing foreign matter inside inner yoke 120, and step S104 of attaching electric field ring 150 to objective lens body 2.

The jig 300 that holds the cleaning tool 301 is used in step S102 to remove foreign matter from within the inner yoke 120.

Figure 19 is a cross-sectional view that shows a schematic diagram of a cleaning tool 301 held by a jig 300 removing foreign matter from inside the inner yoke 120.

First, as shown in Figures 17 and 18, multiple cleaning tools 301 are fixed to the fixing part 320 of the jig 300. The cleaning tools 301 can be fixed to the fixing part 320 by inserting the cleaning tools 301 into the holes 322 of the fixing part 320.

Next, as shown in FIG. 19, the fitting portion 312 of the jig 300 is fitted into the opening 112 of the outer yoke 110.

Specifically, when the fitting portion 312 is inserted into the opening 112, the top surface 311 of the housing 310 abuts against the surface 114 at the tip of the outer yoke 110. This prevents the jig 300 from tilting relative to the outer yoke 110. When the top surface 311 abuts against the surface 114, the fitting portion 312 fits into the opening 112. In this way, the fitting portion 312 of the jig 300 can be fitted into the opening 112 of the outer yoke 110. At this time, the opening 112 of the outer yoke 110 is blocked by the jig 300.

By fitting the fitting portion 312 into the opening 112 of the outer yoke 110, the four cleaning tools 301 can be introduced into the inner yoke 120 as shown in FIG. 19. In the illustrated example, two cleaning tools 301 are introduced inside the inner yoke 120 and are in contact with the inner surface of the inner yoke 120. The other two cleaning tools 301 are introduced outside the inner yoke 120 and are in contact with the outer surface of the inner yoke 120. Here, the concentricity of the jig 300 and the objective lens body 2 (outer yoke 110) is regulated by the fitting of the opening 112 and the fitting portion 312. Therefore, the four cleaning tools 301 can be introduced into appropriate positions within the inner yoke 120.

Next, the jig 300 is rotated. This allows the two cleaning tools 301 introduced inside the inner yoke 120 to remove foreign matter inside the inner yoke 120, and allows the two cleaning tools 301 introduced outside the inner yoke 120 to remove foreign matter outside the inner yoke 120. For example, a user can rotate the jig 300 by holding the housing 310 and rotating the housing 310.

As shown in FIG. 20, the height of the cleaning tool 301 can be adjusted by changing the position where the fixing part 320 is fixed with the fixing screw 330.

After cleaning of the inner yoke 120 is completed, attach the electric field ring 150 to the objective lens body 2.

3.3. Effects The cleaning method for the objective lens 100 includes the steps of fixing a plurality of cleaning tools 301 to a jig 300 having an engagement portion 312 that fits into the opening 112 of the outer yoke 110 of the objective lens 100, fitting the engagement portion 312 into the opening 112 and introducing the plurality of cleaning tools 301 into the inner yoke 120, and moving the jig 300 to clean the inside of the inner yoke 120 with the plurality of cleaning tools 301. Since the jig 300 has the engagement portion 312 that fits into the opening 112 of the objective lens 100, the cleaning tool 301 can be introduced to an appropriate position in the objective lens 100. Therefore, the cleaning method for the objective lens 100 makes it easy to clean the inside of the objective lens 100.

In the cleaning method for the objective lens 100, two of the four cleaning tools 301 (first cleaning tools) are introduced inside the acceleration/deceleration electrode 140, and the other two of the four cleaning tools 301 (second cleaning tools) are introduced outside the acceleration/deceleration electrode 140. Therefore, in the cleaning method for the objective lens 100, foreign matter on both the inside and outside of the acceleration/deceleration electrode 140 can be removed.

In the method for cleaning the objective lens 100, the housing 310 is provided with a long hole 314 extending in the height direction, and the fixing part 320 can be fixed to the housing 310 by passing a fixing screw 330 through the long hole 314. Therefore, the height of the cleaning tool 301 can be adjusted.

The jig 300 includes a fitting portion 312 that fits into the opening 112 of the outer yoke 110 of the objective lens 100 of the scanning electron microscope 10, and a fixing portion 320 for fixing multiple cleaning tools 301. The fitting portion 312 is fitted into the opening 112, thereby introducing multiple cleaning tools 301 into the objective lens 100. In this way, since the jig 300 has the fitting portion 312 that fits into the opening 112 of the objective lens 100, the cleaning tool 301 can be introduced into an appropriate position within the objective lens 100. Therefore, the inside of the objective lens 100 can be easily cleaned.

3.4 Modifications Below, differences from the example of the jig 300 described above will be described, and a description of similarities will be omitted.

3.4.1. First Modification FIG. 21 is a cross-sectional view that shows a schematic view of a state in which foreign matter is being removed from inside the inner yoke 120 by a cleaning tool 301 held by a jig 300. As shown in FIG.

As shown in FIG. 21, the jig 300 may be placed on the sample stage 14, and the sample stage 14 may be operated to clean the inside of the inner yoke 120 with the cleaning tool 301.

For example, by moving the jig 300 in the height direction on the sample stage 14, the fitting portion 312 of the jig 300 installed on the sample stage 14 can be fitted into the opening 112 of the outer yoke 110.

In addition, by rotating the jig 300 on the sample stage 14, foreign matter on the inside of the inner yoke 120 and on the outside of the inner yoke 120 can be removed.

22 is a diagram for explaining a jig 400 according to a second modified example. Hereinafter, in the jig 400, members having the same functions as the components of the jig 300 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 22, the jig 400 has a rotation mechanism 410 that rotates the housing 310. The rotation mechanism 410 includes, for example, a motor, and rotates the housing 310 by the rotational force of the motor. By rotating the housing 310, the fixed part 320 rotates, and the cleaning tool 301 fixed to the fixed part 320 rotates. By rotating the cleaning tool 301, foreign matter on the inside of the inner yoke 120 and the outside of the inner yoke 120 can be removed. Note that the configuration of the rotation mechanism 410 is not particularly limited.

In the above embodiment, the jig 300 is used to clean the objective lens 100 of the scanning electron microscope 10. However, the jig 300 may be used to clean the objective lens 200 of the scanning electron microscope 20. When the jig 300 is used to clean the objective lens 200, the same effects as when the jig 300 is used to clean the objective lens 100 can be achieved.

The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment. A substantially identical configuration is, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention also includes a configuration that has the same action and effect as the configuration described in the embodiment, or a configuration that can achieve the same purpose. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment.

2...Objective lens body, 10...Scanning electron microscope, 11...Electron source, 12...Condenser lens, 13...Scanning deflector, 14...Sample stage, 15...Electron detector, 20...Scanning electron microscope, 100...Objective lens, 101...Objective lens, 102...Objective lens, 110...Outer yoke, 112...Opening, 114...Surface, 120...Inner yoke, 130...Magnetic pole piece, 132...Upper surface, 140...Acceleration/deceleration electrode, 150...Field ring, 151...Orifice, 152...Threaded portion, 153...Recess, 154...Shaft portion, 155...Groove, 156...Hole, 160...Nut, 162...Female thread, 170...Support ring, 172...Ball, 173...Elastic body, 200...Objective Lens, 201...objective lens, 210...outer yoke, 220...inner yoke, 230...tip electrode, 231...orifice, 232...threaded portion, 234...shaft portion, 235...hole, 236...butting surface, 238...flange portion, 240...nut, 242...internal thread, 244...fitting hole, 246...surface, 250...insulating member, 270...insulating ring, 272...insulating bush, 274...fixing screw, 276...base flange, 280...terminal, 282...wiring, 300...jig, 301...cleaning tool, 310...casing, 311...upper surface, 312...fitting portion, 314...long hole, 320...fixing portion, 322...hole, 330...fixing screw, 400...jig, 410...rotation mechanism

Claims (22)

An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
A pole piece having a diameter larger than that of the shaft portion is fixed to the electrode,
the fitting hole is an opening at a tip end of the outer yoke,
the pole piece has an abutment surface that abuts against a tip of the outer yoke when the shaft portion is fitted into the fitting hole,
The objective lens, in which the coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion. In claim 1,
The retaining portion is a nut,
The objective lens, wherein the held portion is a screw provided on the electrode. In claim 1 or 2 ,
The objective lens, wherein the holding portion is fixed to the outer yoke or the inner yoke. In any one of claims 1 to 3 ,
An objective lens including an acceleration/deceleration electrode disposed within the inner yoke for accelerating or decelerating electrons. An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
A flange portion having a diameter larger than that of the shaft portion;
Including,
The fitting hole is provided in the holding portion,
the flange portion has an abutment surface that abuts against a surface of the holding portion when the shaft portion is fitted into the fitting hole,
The objective lens, in which the coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion. In claim 5 ,
The retaining portion is a nut,
The objective lens , wherein the held portion is a screw provided on the electrode . In claim 5 or 6,
The objective lens, wherein the holding portion and the electrode are electrically insulated from the outer yoke and the inner yoke. In claim 7,
The retaining portion is disposed within the outer yoke,
An insulating member is disposed between the holding portion and the outer yoke. In claim 8,
the insulating member is an O-ring,
The objective lens hermetically seals the space between the outer yoke and the holder. In any one of claims 5 to 9,
The inner yoke and the electrode are spaced apart from each other. An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
A pole piece having a diameter larger than that of the shaft portion is fixed to the orifice,
the fitting hole is an opening at a tip end of the outer yoke,
the pole piece has an abutment surface that abuts against a tip of the outer yoke when the shaft portion is fitted into the fitting hole,
The concentricity of the orifice and the objective lens body is regulated by the fit of the fitting hole and the shaft portion. An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
A flange portion having a diameter larger than that of the shaft portion;
Including,
The fitting hole is provided in the holding portion,
the flange portion has an abutment surface that abuts against a surface of the holding portion when the shaft portion is fitted into the fitting hole,
The concentricity of the orifice and the objective lens body is regulated by the fit of the fitting hole and the shaft portion. An objective lens body;
an electrode detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
An inner yoke disposed within the outer yoke;
A nut portion that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A threaded portion held by the nut portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The screw portion is located at a tip of the electrode,
the screw portion and the nut portion are screwed together with some backlash to hold the electrode, and the coaxiality between the electrode and the objective lens body is not restricted,
The threaded portion is screwed into the nut portion, so that the shaft portion is fitted into the fitting hole,
The objective lens, in which the coaxiality between the electrode and the objective lens body is regulated by the fit between the fitting hole and the shaft portion. An objective lens body;
an orifice detachable from the objective lens body;
Including,
The objective lens body includes:
Outer yoke and
an inner yoke disposed within the outer yoke;
A nut portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A threaded portion held by the nut portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
the threaded portion is located at a tip of the orifice,
the screw portion and the nut portion are screwed together with some play to hold the orifice, and the coaxiality between the orifice and the objective lens body is not restricted,
The threaded portion is screwed into the nut portion, so that the shaft portion is fitted into the fitting hole,
The concentricity of the orifice and the objective lens body is regulated by the fit of the fitting hole and the shaft portion. An electron microscope comprising the objective lens according to any one of claims 1 to 14 . A method for cleaning an objective lens of an electron microscope, comprising the steps of:
Removing an electrode disposed at a tip of an inner yoke of the objective lens;
cleaning the inside of the inner yoke;
Including,
The objective lens includes an objective lens body;
The objective lens body includes:
Outer yoke and
The inner yoke disposed within the outer yoke;
A holding part that detachably holds the electrode;
Including,
the electrode is disposed at a tip of the inner yoke,
The electrode is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The fitting of the fitting hole and the shaft portion regulates the coaxiality of the electrode and the objective lens body,
a step of fixing a cleaning tool to a jig having a fitting portion that fits into the fitting hole;
a step of fitting the fitting portion into the fitting hole to introduce the cleaning tool into the inner yoke;
and moving the jig to clean the inside of the inner yoke with the cleaning tool . A method for cleaning an objective lens of an electron microscope, comprising the steps of:
Removing an orifice disposed at a tip of an inner yoke of the objective lens;
cleaning the inside of the inner yoke;
Including,
The objective lens includes an objective lens body;
The objective lens body includes:
Outer yoke and
The inner yoke disposed within the outer yoke;
A holding portion that detachably holds the orifice;
Including,
The orifice is disposed at a tip end of the inner yoke,
The orifice is
A held portion held by the holding portion;
a shaft portion that is fitted into a fitting hole provided in the objective lens body;
Including,
The concentricity between the orifice and the objective lens body is regulated by the fitting between the fitting hole and the shaft portion,
a step of fixing a cleaning tool to a jig having a fitting portion that fits into the fitting hole;
a step of fitting the fitting portion into the fitting hole to introduce the cleaning tool into the inner yoke;
and moving the jig to clean the inside of the inner yoke with the cleaning tool . In claim 16 or 17,
In the step of fixing the cleaning tools, a plurality of cleaning tools are fixed to the jig. In claim 18 ,
the electron microscope includes an acceleration/deceleration electrode disposed in the inner yoke for accelerating or decelerating electrons;
The acceleration/deceleration electrode is cylindrical, and the electron beam passes through the inside of the electrode.
A first cleaning tool of the plurality of cleaning tools is introduced inside the cylindrical acceleration/deceleration electrode,
A method for cleaning an objective lens, wherein a second cleaning tool of the plurality of cleaning tools is introduced outside the cylindrical acceleration/deceleration electrode. In any one of claims 16 to 19 ,
The electron microscope has a sample stage,
A method for cleaning an objective lens, comprising the steps of: placing the jig on the sample stage; and introducing the cleaning tool into the inner yoke by moving the jig on the sample stage. A jig for fixing a cleaning tool used for cleaning an objective lens of an electron microscope,
a fitting portion that is fitted into a fitting hole of the objective lens;
A fixing part for fixing the cleaning tool;
Including,
The cleaning tool fixed to the fixing part is introduced into the objective lens by fitting the fitting part into the fitting hole. 22. In claim 21,
A plurality of cleaning tools can be fixed to the fixing portion,
The jig includes a fitting portion that fits into the fitting hole, thereby introducing the cleaning tools fixed to the fixing portion into the objective lens.

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