JP2014022359A - Vacuum retention valve and scanning electron microscope employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of dust by guiding the motion of a valve part through a rotary roller and a rotating member to prevent impulse which is generated when a main body part moves forward or backward.SOLUTION: In a vacuum retention valve and a scanning electron microscope employing the same, the vacuum retention valve retains the inside of a chamber vacuum by sealing an opening part formed in the chamber. The vacuum retention valve comprises: a main body part to which a motive force is applied from the outside and which performs a translational motion along a wall surface of the chamber; a stopper which is positioned on the chamber and includes a rotary roller; a valve part which moves while connecting with the main body part and opens/closes the chamber while bringing one surface into contact with the rotary roller and switching a moving direction between a direction closer to the opening part and a direction separate from the opening part; and a rotating member which is positioned on the main body part so as to face the rotary roller, is brought into contact with another surface of the valve part when the stopper and the valve part are contacted, and guides the moving direction of the valve part.

Description

  The present invention relates to a vacuum holding valve and an electron microscope using the same, and more specifically, a vacuum holding valve capable of preventing the generation of particles when the valve is opened and closed while holding the vacuum inside the lens barrel, and the same It relates to the used electron microscope.

  In recent years, not only the trend of miniaturization of information equipment, but also the advanced material field, there is an urgent need for information on the shape of microstructures or material surfaces due to the industrialization of ultrafine technology. In particular, since the latter half of the 1990s, nano research has become active worldwide, and research for investigating the structure and properties of nanomaterials has progressed. The electron microscope plays an important role in this.

The inside of the tube of the vacuum microscope must hold a vacuum to prevent light scattering and protect the filaments that generate electrons, but must hold a high vacuum of 10 ⁻¹⁰ to 10 ^−8. Don't be. In order to hold this, a vacuum holding valve that opens and closes the light inlet of the lens barrel is used.

  FIG. 1 is a front view schematically showing a conventional vacuum holding valve. The conventional vacuum holding valve 1 includes a chamber 10, a main body portion 20, a valve portion 30, a sealing portion 31, a stopper 40, and a leaf spring 50.

  Referring to FIG. 1, the valve part 30 is connected to the main body part 20 by a plate spring 50 and moves to the left in a state where the valve part 30 is connected to the main body part 20 by a cylinder 12 to collide with the stopper 40. Become. At the time of a collision, the valve part 30 moves to the opening part 11 side along the slope of the valve part 30 by the pin 41 formed on the outer surface of the stopper 0.

  In the case of such a prior art, the valve part 30 has a problem that a part of the valve part 30 is broken due to a collision with the pin 41 to generate dust or the valve part 30 is damaged. In addition, there is a problem that the collision between the main body portion 20 and the valve portion 30 frequently occurs and dust is generated, or the main body portion 20 or the valve portion 30 is damaged. Such generation of dust contaminates the vacuum state inside the chamber and causes a problem that the light source is damaged by colliding with electrons generated by the light source.

  On the other hand, by connecting the main body 20 and the valve unit 30 by the plate spring 50, the plate spring 50 mainly controls the process by which the valve unit 30 opens and closes the opening 11. However, it is difficult to adjust the elastic force of the plate spring 50, and dust is generated as the plate spring 50 is largely deformed.

  In addition, the translational motion of the valve unit 30 that moves in combination with the main body unit 20 depends on the cylinder 12, but the valve unit 30 moves forward or backward even when the sealing unit 31 is in contact with the wall surface of the chamber 10. There arises a problem that the sealing part 31 is broken due to friction or dust is generated.

  An object of the present invention is to solve such a conventional problem, and reduces the impact generated at the time of opening and closing of the valve and the collision between the stopper and the valve unit, and is separate from the movement of the main body unit. The present invention provides a vacuum holding valve that suppresses the generation of dust by providing a valve portion so as to be able to move, and preventing the sealing portion from sliding along the wall surface of the chamber, and a scanning electron microscope using the same. .

  It is another object of the present invention to provide a vacuum holding valve that can simultaneously support the opposing surfaces of the bulb portion to uniformly seal the light inlet and maintain a high vacuum, and a scanning electron microscope using the same.

  The object of the present invention is to provide a vacuum holding valve that seals an opening formed in a chamber and keeps the inside of the chamber in a vacuum according to the present invention. A main body portion to be moved, a stopper provided on the chamber and provided with a rotating roller, and connected to the main body portion, and one surface is in contact with the rotating roller and the moving direction is a direction on the opening side or A valve part that is changed to one of the directions separated from the opening part to open and close the chamber, and is positioned on the main body part so as to face the rotating roller, and when the stopper and the valve part are in contact with each other, And a rotating member that contacts the other surface of the valve portion and guides the moving direction of the valve portion.

  Here, when the separation distance between the rotating roller and the rotating member decreases when the valve unit is in contact with the rotating roller and the rotating member, the valve unit approaches the opening side, and the rotating roller When the separation distance between the rotating member and the rotating member increases, the valve portion can be separated from the opening side.

  Further, the surface of the valve portion that contacts the rotating roller is inclined so as to be deflected toward the stopper side toward the opening portion so that the valve portion moves toward the opening portion when contacting with the rotating roller. be able to.

  Here, the end portion of the main body portion protrudes above the valve portion, and is formed with a slit groove that guides the valve portion to move in a direction opposite to the moving direction of the main body portion when contacting the rotating roller. The side is positioned so as to be deflected toward the stopper when the chamber is opened while being accommodated in the slit groove, and is positioned so as to be deflected toward the rotating member when the chamber is sealed, and the other side is inserted into the valve portion. And a connecting portion that connects the main body portion and the valve portion.

  Further, the connecting portion is provided along the outer peripheral surface of the shaft member with the concavo-convex portion formed at the end portion inserted into the valve portion side, is in contact with the concavo-convex portion, and is compressed when the chamber is sealed, An elastic member can be provided that is pulled when the chamber is opened.

  Here, a buffer member provided between the main body portion and the valve portion and buffering an impact caused by a restoring force generated when the elastic member is pulled can be further provided.

  In addition, a sealing portion provided on the lower surface of the valve portion and interposed between the wall surface of the chamber and the valve portion when the chamber is sealed can be further provided.

  Here, the apparatus may further include a pair of guide portions provided in the chamber and arranged to be separated from each other so that the main body portion can pass therethrough.

  The object is emitted from a light source, a chamber in which the light source is accommodated and an opening is formed, a vacuum holding valve according to any one of the above provided to seal the chamber, and the light source. A focusing lens for focusing the electron beam at one point, an aperture for converting the wavelength of light passing through the focusing lens, an objective lens for passing the light whose wavelength has been converted by the aperture, a chamber, a vacuum holding valve, and a focusing lens This is achieved by a scanning electron microscope comprising: a lens barrel that houses an aperture and an objective lens; and a stage that supports a sample.

  Here, the apparatus may further include a measurement unit that is provided above the vacuum holding valve and measures the amount of the electron beam emitted from the light source.

  According to the present invention, there is used a vacuum holding valve capable of preventing the generation of dust when the movement of the valve portion is guided by the rotating roller and the rotating member to prevent the impact of the main body portion from moving forward or backward, and to suppress the generation of dust. A scanning electron microscope is provided.

  In addition, the valve part and the main body part are connected by a connecting part, and a buffer member is provided between the valve part and the main body part to prevent contact between the valve part and the main body part. can do.

  In addition, a sealing portion is provided on the lower surface of the valve portion, and the high vacuum inside the chamber can be maintained by preventing the inflow of external air.

  In addition, the connecting part is provided so as to be movable along the slit groove formed in the main body part, and prevents the sealing part from sliding on the wall surface of the chamber when the chamber is sealed, and generation of dust in the sealing part due to friction or Breakage can be prevented.

  Further, since both sides of the valve portion are supported by the rotating member and the rotating roller when the chamber is sealed, the shielding can be held even in a high vacuum by pressing the sealing portion evenly.

  Further, the guide portion is provided so as to be separated from the main body portion as a center, and the movement path of the main body portion can be prevented from being separated.

It is a front view which shows roughly the vacuum holding valve which hold | maintains the vacuum of a chamber in the conventional scanning electron microscope. 1 is a perspective view schematically showing a vacuum holding valve according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view schematically showing a vacuum holding valve according to FIG. 2. FIG. 3 is a cross-sectional view schematically showing a state in which an opening of a chamber is opened in the vacuum holding valve according to FIG. 2. FIG. 3 is a cross-sectional view schematically showing a state where an opening of a chamber is closed in the vacuum holding valve according to FIG. 2. FIG. 3 is a cross-sectional view schematically showing the operation of the valve portion in the vacuum holding valve according to FIG. 2. It is sectional drawing which shows schematically the scanning electron microscope containing the vacuum holding valve | bulb which concerns on 2nd Example of this invention.

  Prior to the description, in various embodiments, components having the same configuration are typically described in the first embodiment using the same reference numerals, and other embodiments have configurations different from the first embodiment. Only will be described.

  Hereinafter, a vacuum holding valve 100 according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  2 is a perspective view schematically showing a vacuum holding valve according to a first embodiment of the present invention, FIG. 3 is an exploded perspective view schematically showing the vacuum holding valve according to FIG. 2, and FIG. 2 is a cross-sectional view schematically showing a state in which the opening of the chamber is opened in the vacuum holding valve according to FIG. 2, and FIG. 5 is a view schematically showing a state in which the opening of the chamber is closed in the vacuum holding valve according to FIG. FIG. 6 is a cross-sectional view schematically showing the operation of the valve portion in the vacuum holding valve according to FIG.

  2 to 6, the vacuum holding valve 100 according to the first embodiment of the present invention includes a main body part 110, a valve part 120, a sealing part 130, a connecting part 140, a stopper 150, and a rotating member. 160, a buffer member 170, and a guide part 180.

  The vacuum holding valve 100 according to one embodiment of the present invention minimizes the contact between the main body 110 and the valve unit 120 to suppress the generation of dust, and the opening 106 of the chamber 105 is sealed by the valve unit 120. Further, the valve unit 120 is provided to be movable along the slit groove in a direction opposite to the movement direction of the main body unit 110, and the sealing unit 130 is prevented from sliding along the wall surface of the chamber 105. Provided to suppress breakage and generation of dust.

  The right side surface of the main body 110 is connected to the cylinder 107 and translates according to the reciprocating motion of the cylinder 107. Further, the left side surface of the main body 110 protrudes above a valve portion 120 described later, and is connected to the valve portion 120 by a connecting portion 140 described later, and performs translational movement in a state where the valve portion 120 is coupled to the main body 110. To transmit power.

  On the other hand, a slit groove 111 formed longer in the length direction than the width direction of the main body 110 is formed in a portion protruding so as to be connected to the valve portion 120 on the upper left side surface of the main body 110.

  A connecting portion 140 described later is inserted into the slit groove 111 to connect the main body portion 110 and the valve portion 120, and the valve portion 120 can move along the slit groove 111. A detailed description thereof will be described later.

  The valve part 120 is connected to the main body part 110 and reciprocates by the cylinder part 107 while being connected to the main body part 110. When the valve unit 120 moves to the left side by the cylinder unit 107 and contacts the rotating roller 151, the moving direction is switched to the opening 106 side along the inclination direction of the left side surface of the valve unit 120, and the valve unit 120 contacts the surface of the chamber 105. The opening 106 is sealed. Further, when the valve unit 120 moves to the right side by the cylinder unit 107, the valve unit 120 moves along the inclination direction of the right side surface of the valve unit 120 that contacts the rotating member 160, and when a buffer member 170 described later contacts the main body unit 110, It moves to the right in a state where it is connected to the main body 110.

  Further, at least the left side surface of the valve unit 120 is inclined so as to be deflected outward toward the opening, and the rotating roller 151 causes the valve unit 120 to follow the direction of inclination of the outer surface of the valve unit 120. It moves to the opening 106 side. The right side surface is preferably provided so as to be symmetrical with the left side surface, that is, the cross-sectional shape of the valve portion 120 is preferably trapezoidal. This is because the rotating member 160 described later guides the direction in which the valve unit 120 moves toward the main body 110, and the restoring force of the elastic member 142 described later rotates the rotating member 160 to cause the buffer member 170 and the main body to move. The impact generated at the time of contact with the portion 110 is reduced.

  The sealing unit 130 is provided on the lower surface of the valve unit 120 and is compressed so as to be in close contact with the wall surface of the chamber 105 when the opening 106 is sealed. Since the sealing portion 130 prevents external air from flowing between the valve portion 120 and the opening portion 106, the inside of the chamber 105 can be maintained at a high vacuum. According to the first embodiment of the present invention, the sealing unit 130 is provided as an O-ring, but is not limited thereto.

  The connecting part 140 includes a shaft member 141 that is inserted into the slit groove 111 on the upper side and inserted into the valve part 120 on the lower side to connect the main body part 110 and the valve part 120, and an elastic member 142.

  4 to 6, the shaft member 141 serves as a main frame of the connecting portion 140, the upper side of the shaft member 141 is movable along the slit groove 111, and the lower side is uneven. A portion is formed to support the elastic member 142. That is, the shaft member 141 is coupled to the valve unit 120, and the shaft member 141 and the valve unit 120 move together when the valve unit 120 contacts the rotating roller 151.

  The elastic member 142 is provided along the outer peripheral surface of the shaft member 141, the upper side is in contact with a buffer member 170, which will be described later, and the lower side is in contact with an uneven portion of the shaft member 141, and the buffer member 170 and the uneven portion There will be a tension or compression movement between.

  More specifically, when the main body part 110 moves to the left side, the valve part 120 contacts the rotating roller 151 and moves to the opening part 106 side along the outer surface of the valve part 120, so that the elastic member 142 is compressed. When the main body part 110 moves to the right side, the valve part 120 moves to the upper side by the restoring force of the compressed elastic member 142. According to the first embodiment of the present invention, a spring is provided as the elastic member 142, but is not limited thereto.

  The coupling relationship among the main body part 110, the valve part 120, and the connecting part 140 will be further described. The shaft member 141 is inserted into the slit groove 111 so as to be movable along the slit groove 111 of the main body part 110. The end portion of the shaft member 141 that has passed through is inserted into the valve portion 120.

  Moreover, the elastic member 142 is provided along the outer peripheral surface of the shaft member 141, and the elastic member 142 is accommodated inside the valve portion 120 and is not exposed to the outside. In other words, the elastic member 142 performs a compression or tensile motion inside the valve portion 120 and raises the valve portion 120 by a restoring force during the tensile motion.

  On the other hand, the uneven portion of the shaft member 141 contacts the inner surface of the valve portion 120 into which the shaft member 141 is inserted, and when the shaft member 141 moves along the slit groove 111, the valve portion 120 is also integrated with the shaft member 141. Will move.

  The stopper 150 includes a rotating roller 151 whose position is fixed on the chamber 105 and that switches the movement direction of the valve unit 120 that moves while being connected to the main body unit 110 to the inclination direction of the outer surface of the valve unit 120. That is, the stopper 150 stops the movement of the main body part 110 and switches the movement direction of the valve part 120 so that the valve part 120 seals the opening 106.

  The rotating roller 151 directly contacts the valve unit 120 and switches the moving direction of the valve unit 120 through rotation. That is, when the valve unit 120 moves forward in contact with the rotating roller 151, the rotating roller 151 rotates clockwise to guide the moving direction so that the valve unit 120 moves forward and lower and seals the opening. The direction of movement is guided so that the valve portion rotates clockwise and the valve portion moves backward and rises to open the opening.

  The rotating member 160 is provided on the main body 110 so as to face the rotating roller 151, and contacts the right side surface of the valve unit 120 so that the valve unit 120 moves toward the opening 106 and seals the chamber 105. The movement path is guided, and the movement path along which the valve unit 120 moves to the original state is guided when the valve unit 120 moves away from the opening 106 side.

  That is, the rotating member 160 rotates together with the rotating roller 151 to rotate counterclockwise so that the valve unit 120 is lowered. When the valve unit 120 is raised, the rotating member 160 rotates clockwise to move the valve unit 120 up and down. Will guide you.

  The buffer member 170 is provided between the main body part 110 and the valve part 120 and relieves an impact that may be generated by the elastic force of the elastic member 142.

  The guide parts 180 are provided in the chamber so as to be separated from each other, and guide the translational movement direction of the main body part 110 so that the main body part 110 can pass between the guide parts 180. Although the direction of the translational movement of the main body 110 is determined by the cylinder 107, the main body 110 can be separated from the movement according to the length of the cylinder 107, which is prevented.

  Next, the operation of the vacuum holding valve in which the opening portion 106 is opened and closed by the valve portion 120 in the first embodiment of the vacuum holding valve and the scanning electron microscope using the same will be described. Prior to the description, the moving direction of the main body 110 is defined as the X-axis direction, and the direction perpendicular to the moving direction is defined as the Y-axis direction.

  4 to 6, the valve unit 120 receives power from the cylinder unit 107 along the X-axis direction while being connected to the main body unit 110 until the valve unit 120 contacts the rotating roller 151. Will move.

  Even when the valve unit 120 comes into contact with the rotating roller 151, the main body unit 110 moves along the X-axis direction. The valve unit 120 moves toward the opening 106 along the inclined direction of the inclined outer surface as the rotating roller 151 rotates along the inclined outer surface of the valve unit 120. That is, it moves not only in the X-axis direction but also in the -Y-axis direction. At this time, the rotating member 160 also contacts the right side surface of the valve unit 120 and rotates to guide the movement of the valve unit 120.

  On the other hand, when the valve unit 120 moves in the −Y-axis direction, the elastic member 142 provided on the inner surface of the valve unit 120 and provided between the concavo-convex part and the buffer member 170 is compressed. Although the position of the concavo-convex part in the Y-axis direction is fixed, the buffer member 170 coupled to the valve part 120 also moves in the −Y-axis direction, so that the space between the concavo-convex part and the buffer member 170 becomes narrow, so that elasticity The member 142 will also be compressed.

  At the same time, the valve portion 120 moves along the slit groove 111 in the direction opposite to the movement direction of the main body portion 110 (−X axis direction). If the valve unit 120 does not move along the slit groove 111, the valve unit 120 moves diagonally along the slope, so that the movement distance of the valve unit 120 in the X-axis direction is the same as that of the main body unit 110 in the X-axis direction. This may be less than the moving distance and may damage the connecting part 140. In order to prevent this, the valve portion 120 moves in the −X axis direction along the slit groove 111.

  That is, when the main body 110 is moved to the maximum in the X-axis direction and stopped, the sealing part 130 on the lower surface of the valve part 120 is compressed and brought into close contact with the surface of the chamber 105, and the valve part 120 is positioned on the right side of the slit groove 111. It will be positioned to be deflected and stop. At this time, the opening 106 is located inside the sealing part 130, and the inflow of air is prevented by the sealing part 130 and the valve part 120.

  On the other hand, when the valve unit 120 is in a stopped state with the opening 106 sealed, the rotating roller 151 and the rotating member 160 come into contact with and support both surfaces of the valve unit 120, thereby uniformly sealing the sealing unit 130. It is possible to maintain a vacuum even in a high vacuum state by applying pressure.

  On the other hand, the operation of the valve unit 120 when the chamber 105 is opened will be described. The main body unit 110 is moved in the −X axis direction by the cylinder unit 107.

  The valve part 120 moves in the Y-axis direction by the restoring force of the elastic member 142 as the main body part 110 moves. The restoring force means a force that acts in a direction to return to the equilibrium state again when the equilibrium state is broken in the equilibrium system. In the case of the elastic member 142 such as a spring, the original state is restored in the compressed state. It means a force that is pulled to the state of (1) or is compressed again to the original state in the state of being pulled.

  At this time, such a restoring force guides the movement in the Y-axis direction by the rotating member 160 and moves not only in the Y-axis direction but also in the X-axis direction along the slit groove 111. That is, the rotation of the rotating member 160 moves the valve unit 120 along the slope direction of the valve unit 120.

  In other words, the valve unit 120 comes into contact with the rotating roller 151 on the left side and the rotating member 160 on the right side before the chamber 105 is sealed. When the main body 110 moves to the left side in order to seal the chamber 105, that is, when the separation distance between the rotating roller 151 and the rotating member 160 that has been in contact with the valve unit 120 is reduced, the rotating roller 151 is rotated clockwise. The rotating member 160 rotates counterclockwise to push the valve unit 120 toward the opening 106, and when the separation distance between the rotating roller 151 and the rotating member 160 is minimized, the sealing unit 130 moves to the chamber 105. The chamber 105 is sealed in contact with the wall surface.

  On the other hand, when the separation distance between the rotation roller 151 and the rotation member 160 that are held to a minimum increases, it becomes impossible to support the force that compresses the elastic member 142 accommodated in the valve unit 120, and the valve unit 120 moves away from the opening 106 side. This can be explained by the restoring force of the elastic member 142, and since this has been described above, a detailed description thereof will be omitted. If it is assumed that the main body 110 moves minutely in the direction opposite to the stopper 150, the rotating roller 151 rotates counterclockwise, and the rotating member 160 rotates clockwise, while the valve unit 120 moves from the opening 106. It will guide the movement in the separated direction.

  When the buffer member 170 comes into contact with the main body 110, the valve unit 120 moves in the −X axis direction while being connected to the main body 110.

  That is, the rotation of the rotating roller 151 and the movement of the valve portion 120 by the slit groove 111 prevent the sealing portion 130 from sliding on the surface of the chamber 105, and dust caused by friction between the sealing portion 130 and the surface of the chamber 105. Occurrence or damage will be prevented.

  Next, a vacuum holding valve according to a second embodiment of the present invention and a scanning electron microscope 200 using the same will be described.

  FIG. 7 is a cross-sectional view schematically showing a scanning electron microscope including a vacuum holding valve according to a second embodiment of the present invention.

  Referring to FIG. 7, the vacuum holding valve and the scanning electron microscope using the same according to the second embodiment of the present invention are inventions related to a scanning electron microscope including a vacuum holding valve, and include a light source 210 and a vacuum holding valve 220. A chamber 230, a focusing lens 240, an aperture 250, an objective lens 260, a lens barrel 270, a stage 280, and a measurement unit 290.

  The light source 210 is a member for scanning an electron beam generated by heating a negative electrode inside a lens barrel 270 described later to the lower stage side.

  The vacuum holding valve 220 is a device for holding a chamber 230, which will be described later, which houses the light source 210, in a high vacuum, and has already been described in the first embodiment of the present invention. In the second embodiment of the present invention, it is expressed that it is accommodated in the chamber 230, but is not limited thereto, and is provided outside the chamber 230 and in contact with the lower surface of the chamber 230. It doesn't matter.

  The chamber 230 is a space provided to accommodate the light source 210 and is provided to separately accommodate the light source 210 so as to maintain a high vacuum in order to prevent the light source 210 from being damaged. Although the separate chamber 230 is not provided and the light source 210 can be directly accommodated in the lens barrel 270, a large amount of cost is consumed for manufacturing the lens barrel 270 in order to keep the interior of the lens barrel 270 in a high vacuum. Therefore, it is preferable to provide the chamber 230 separately.

  The focusing lens 240 is a member for focusing the electron beam emitted from the light source 210 on one point.

  The aperture 250 is a member for converting the electron beam focused by passing through the focusing lens 240 into a form having a constant wavelength.

  The objective lens 260 is a lens positioned close to the sample, and since this is a well-known technique, a detailed description thereof is omitted.

  The lens barrel 270 is an exterior material for accommodating therein the light source 210, the vacuum holding valve 220, the chamber 230, the focusing lens 240, the aperture 250, and the objective lens 260, and an electron beam is received therein. The end on the emission side, that is, the end on the sample side on which the sample is mounted is configured to maintain a vacuum state.

  The stage 280 is a place for supporting a sample to be measured by the vacuum holding valve according to the second embodiment of the present invention and the scanning electron microscope 200 using the same.

  The measurement unit 290 is a device that is provided on the upper surface of the main body 110 and measures the concentration of the electron beam emitted from the light source 210. According to the second embodiment of the present invention, the measuring unit 290 is provided as a copper plate, but is not limited thereto.

  In addition, it is preferable to further include a feed-through 291 connected to the measurement unit 290 to transmit data measured from the measurement unit 290 to the outside, and the measured data can be confirmed through the feed-through. In the second embodiment of the present invention, the feed through 291 is provided on the stopper 150 side, but the present invention is not limited to this.

  Since the operation of the vacuum holding valve according to the second embodiment of the present invention and the scanning electron microscope 200 using the same is the same as the operation of a known scanning electron microscope, detailed description thereof is omitted here.

  Further, since the operation method of the vacuum holding valve 220 has been described in the operation of the first embodiment of the present invention, a detailed description thereof will be omitted.

  However, the measurement unit 290 measures the concentration of the electron beam emitted from the light source 210 inside the chamber. The measured concentration is transmitted to the feed-through 291 and can be confirmed by utilizing an external separate device.

  The scope of the present invention is not limited to the above-described embodiments, but can be embodied as various embodiments within the scope of the appended claims. The scope of the description of the claims of the present invention is within the various scope that can be modified by any person having ordinary knowledge in the technical field to which the invention belongs without departing from the gist of the present invention claimed in the claims. It is assumed that it is inside.

DESCRIPTION OF SYMBOLS 100 Vacuum holding valve 110 Main body part 120 Valve part 130 Sealing part 140 Connection part 150 Stopper 160 Rotating member 170 Buffer member 180 Guide part 200 Scanning electron microscope 210 Light source 220 Vacuum holding valve 230 Chamber 240 Focusing lens 250 Aperture 260 Objective lens 270 Lens tube 280 Stage 290 Measuring unit

Claims (10)

A vacuum holding valve that seals an opening formed in the chamber and holds the inside of the chamber in a vacuum,
A body that is externally powered and translates along the wall of the chamber;
A stopper located on the chamber and comprising a rotating roller;
It moves in a state of being connected to the main body, and one surface comes into contact with the rotating roller, and the moving direction is switched to either the opening side or the direction away from the opening to open and close the chamber. A valve section;
A rotating member that is positioned on the main body so as to face the rotating roller, contacts the other surface of the valve portion when the stopper and the valve portion are in contact, and guides the moving direction of the valve portion; Vacuum holding valve characterized by   When the separation distance between the rotating roller and the rotating member decreases when the valve unit is in contact with the rotating roller and the rotating member, the valve unit approaches the opening side, and the rotating roller and the rotating member are rotated. The vacuum holding valve according to claim 1, wherein when the separation distance from the member increases, the valve portion is separated from the opening side.   The surface of the valve portion in contact with the rotating roller is deflected toward the stopper side toward the opening side so that the valve portion moves toward the opening side when contacting with the rotating roller. 2. The vacuum holding valve according to claim 1, wherein the vacuum holding valve is inclined so as to be inclined. The end portion of the main body portion protrudes above the valve portion, and a slit groove is formed to guide the valve portion to move in a direction opposite to the moving direction of the main body portion when the valve portion contacts the rotating roller. And
One is positioned so as to be deflected toward the stopper when the chamber is opened while being accommodated in the slit groove, and is positioned so as to be deflected toward the rotating member when the chamber is sealed. The vacuum holding valve according to claim 3, further comprising a connecting portion that is inserted into the valve portion and connects the main body portion and the valve portion. The connecting portion is
A shaft member in which an uneven portion is formed at an end portion inserted into the valve portion side;
The elastic member which is provided along the outer peripheral surface of the shaft member, contacts the uneven portion, is compressed when the chamber is sealed, and is pulled when the chamber is opened. Vacuum holding valve.   The vacuum holding valve according to claim 5, further comprising a buffer member provided between the main body portion and the valve portion and buffering an impact caused by a restoring force generated when the elastic member is pulled.   The vacuum holding valve according to claim 1, further comprising a sealing portion provided on a lower surface of the valve portion and interposed between the wall surface of the chamber and the valve portion when the chamber is sealed. .   The vacuum holding valve according to claim 1, further comprising a pair of guide portions provided in the chamber and arranged to be separated from each other so that the main body portion can pass therethrough. A light source;
A chamber containing the light source and having an opening formed therein;
The vacuum holding valve according to any one of claims 1 to 8, which is provided so as to seal the chamber;
A focusing lens for focusing the electron beam emitted from the light source at one point;
An aperture for converting the wavelength of light passing through the focusing lens;
An objective lens through which light having a wavelength converted by the aperture passes;
A barrel that houses the chamber, the vacuum holding valve, the focusing lens, the aperture, and the objective lens;
A scanning electron microscope comprising a stage for supporting a sample.   The scanning electron microscope according to claim 9, further comprising a measurement unit that is provided on an upper part of the vacuum holding valve and measures an amount of an electron beam emitted from the light source.

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