JP2007242359A - Electrode ring, electron microscope, manufacturing method of electrode ring, and manufacturing method of electron microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out observation of a test piece by an electron microscope excellently. <P>SOLUTION: The electrode ring (1) is arranged opposed to the test piece (9) receiving irradiation of electron beams, and provided with an insulating barrel body (5) of which on one end face opposed to the test piece, a first electrode (2) is formed and, on the other end face, a second electrode (6) is formed, and a barrel resistor (4) which has a hollow hole (3) to become a passing passage of the electron beams, and is inserted in the inner face of the insulating barrel body (5) by connecting one end face to the first electrode (2) and the other end face to the second electrode (6). The barrel resistor (4) is made of a half-conductive glass material containing a conductive material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrode ring disposed opposite to a sample to be irradiated with an electron beam, an electron microscope having the electrode ring, and a method for manufacturing the same, and more particularly to passage of secondary electrons emitted from the electron beam and the sample. The present invention relates to an electrode ring, an electron microscope, and a manufacturing method thereof, in which a structure of a portion surrounding a path is devised.

  In recent years, semiconductor devices have been highly integrated and miniaturized, and accordingly, it has become difficult to observe with the resolution of a conventional optical microscope as means for analyzing the operation and failure of semiconductor devices. Therefore, an analysis method using a scanning electron microscope (SEM) is employed as an effective means instead of the optical method.

  The scanning electron microscope uses an extremely thin electron beam, so that even a highly uneven surface can be focused on almost the entire surface, and a microscopic world full of realism can be observed. The resolution of a scanning electron microscope is determined by the spot diameter of the electron beam, but not only the resolution but also the ability to observe hole bottoms with a large aspect ratio, such as contact holes, has been demanded as semiconductor devices become smaller. .

  Conventionally, by using the retarding method shown in FIG. 10, the acceleration voltage at the electron beam irradiation source is increased to reduce aberrations and improve resolution, and a negative voltage is applied to the sample 9 from the power source 11 to contact holes. A device has been devised to raise the emission trajectory a ′ of secondary electrons from 10 deep hole bottoms.

  However, if the semiconductor device is further miniaturized in the future and the contact hole has a high aspect ratio, it will be difficult to observe the bottom of the hole even with the retarding method. The energy of secondary electrons emitted is very small, so in contact holes with a large aspect ratio, most of the secondary electrons emitted from the bottom collide with the sidewalls before they exit the contact holes and lose energy. It will not be done.

  Therefore, in Patent Document 1, the electrode ring 51 shown in FIG. 11 is arranged between the objective lens 8 and the sample 9 in FIG. 10 in order to increase the pulling efficiency of secondary electrons emitted from the sample. .

JP 2004-327303 A

  The electrode ring 51 is formed by forming electrodes 52 and 53 on the upper and lower end surfaces of the insulating cylinder 54 and further forming a resistance film on the inner surface of the hollow hole 55. For example, the electrode 53 is opposed to the sample 9, the electrode 52 is directed toward the objective lens 8, and the hollow hole 55 is positioned in the passage path of the irradiation electron beam and the emitted secondary electrons, so Placed in.

Since a negative voltage is applied from the power source 11 to the electrode 53 formed on the end face side facing the sample 9 in the electrode ring 51 to make it equipotential with the sample 9, the sample 9 and the electrode ring 51 facing the electrode 9 are below An electric field that prevents acceleration of secondary electrons emitted from the sample 9 is not generated between the end faces. This raises the emission trajectory of the secondary electrons, and the emitted secondary electrons pass through the hollow hole 55 of the electrode ring 51. At this time, the secondary electrons are accelerated by the potential difference between the electrodes 52 and 53, and the secondary electrons (not shown) It is pulled by the positive potential applied to the electron detector and reaches its secondary electron detector.

  In the electron microscope, when the distance between the objective lens 8 and the sample 9 is increased, the resolution is lowered. Therefore, the distance between the objective lens 8 and the sample 9 is about several millimeters, and is therefore arranged between the objective lens 8 and the sample 9. The size of the electrode ring 51 is small accordingly, and the inner diameter of the hollow hole 55 is about several mm. It is difficult to uniformly deposit a resistance film on the inner surface of such a small-diameter hollow hole 55 by vapor deposition or sputtering. Therefore, the resistance value distribution on the inner surface of the hollow hole 55 varies, thereby causing the hollow hole The electric field distribution around the center of the axis at 55 will vary, making it difficult to control the trajectory of the electron beam and secondary electrons as desired.

  In view of the above-mentioned problems, the applicant of the present invention has an electrode ring and an electron microscope that can suppress variations in electric field distribution around the axial center of the hollow hole, which is a passage path for secondary electrons previously emitted from the electron beam and sample. An insulating cylinder having a first electrode formed on one end surface facing the sample and a second electrode formed on the other end surface, and a hollow hole serving as an electron beam passage path An electrode ring comprising: a cylindrical resistor having one end face connected to the first electrode and the other end face connected to the second electrode and fitted inside the insulating cylinder (Japanese Patent Application No. 2005-078546).

  The electron beam is irradiated to the sample through the hollow hole of the resistor. At this time, since a gentle potential distribution is generated in the axial direction due to the potential difference between the first and second electrodes on the inner surface of the hollow hole, the lens aberration of the electron beam irradiated to the sample through the hollow hole is reduced. Can do.

  When the sample is irradiated with an electron beam, secondary electrons are emitted from the surface of the irradiated portion. Here, by setting the first electrode formed on the end face side facing the sample in the electrode ring to be equipotential with the sample, there is 2 between the sample and the end face of the electrode ring facing the sample. There is no electric field that hinders the acceleration of secondary electrons, and the emission trajectory of secondary electrons can be raised.

  The emitted secondary electrons pass through the hollow hole and are accelerated by the potential difference between the first and second electrodes. At this time, the secondary electrons are detected by the positive potential applied to the secondary electron detector. To the vessel.

  And in the said proposal, since it was set as the structure where the passage of an electron beam or an emission secondary electron is surrounded by a resistance material by inserting a cylindrical resistor in the hollow hole of an insulating cylinder, an insulating cylinder In the conventional example (Patent Document 1) in which the resistance film is formed on the inner surface of the hollow hole, the electric field variation due to the uneven formation of the resistance film does not occur, the electric field distribution around the axial center in the hollow hole can be made uniform, It does not interfere with the desired trajectory control of secondary electrons.

  Further, if a structure in which at least one ring-shaped conductive layer is interposed between the both end faces of the resistor, a uniform current flows around the axial center in the conductive layer portion on the inner surface of the hollow hole. And an evenly distributed electric field is generated around the axis center. Even if an uneven current flow is formed around the axial center in the part without the conductive layer, it is made uniform around the axial center in the conductive layer part, so that the entire current flowing along the inner surface of the hollow hole can be seen as a whole. For example, variations in the electric field around the axis center can be suppressed.

  In addition, the conductive film formed by laminating the resistor having the conductive layer interposed therebetween in the axial direction with a plurality of cylinders interposed between the conductive layers, and formed on end surfaces of the plurality of cylinders that are joined to each other. When the conductive layer is formed by diffusion bonding, a highly reliable resistor with improved adhesion between each cylinder and the conductive film, adhesion between each conductive film, and dimensional accuracy can be obtained. In addition, since no adhesive is used, there is no fear of deterioration of the age and dimensional accuracy due to the use of the adhesive.

As described above, the previously proposed invention has various effects. However, in the previously proposed configuration, a block material in which a conductive material is uniformly mixed and sintered in place of a resistive film in a semiconductive ceramic material. The electrode ring cut out from is used. In this case, it is proposed that the thickness of the ring is divided into several parts of about 1 mm, and a Cu electrode film (buffer layer) is formed on the intermediate film to create a more stable electric field. However, this semiconductive ceramic material is a block material of about several tens mm to several hundred mm, and is sintered using a reduction reaction in a special atmosphere (for example, Nz, Ar, H ₂ , CO, etc.). For this reason, sufficient reduction does not proceed in the internal (thickness) direction, and even if there is a buffer layer (Cu), an unacceptable fluctuation or variation in the electric resistance value occurs.

  For this reason, reduction does not proceed in the internal (thickness) direction. Therefore, the resistance value fluctuates inside the material, the electric field distribution is difficult to stabilize, and there is a fatal defect that an electron microscope image is distorted.

  The present invention has been made in view of the above-described problems, and an object thereof is to remove a fatal defect that causes distortion in an electron microscope image.

  The above-described problem is an electrode ring disposed to face a sample that is irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface. The insulating cylinder formed and a hollow hole serving as a passage path for the electron beam, one end face is connected to the first electrode, and the other end face is connected to the second electrode to provide the insulation An electrode ring comprising: a cylindrical resistor fitted on an inner surface of the cylindrical body, wherein the cylindrical resistor is made of a semiconductive glass material including a conductive material. .

  In addition, the above-described problem is an electron microscope having an electrode ring disposed to face a sample to be irradiated with an electron beam, and the electrode ring has a first electrode on one end face facing the sample. An insulating cylinder having a second electrode formed on the other end face, a hollow hole serving as a passage path for the electron beam, one end face being connected to the first electrode, and the other end face being An electron microscope including a cylindrical resistor connected to the inner surface of the insulator and connected to the second electrode, wherein the cylindrical resistor is made of a semiconductive glass material including a conductive material. Solved by the characteristic electron microscope.

  In addition, the above-described problem is an electrode ring disposed to face a sample that is irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface. An insulating cylinder having electrodes formed thereon, and a hollow hole serving as a passage path for the electron beam; one end face is connected to the first electrode, and the other end face is connected to the second electrode; In the electrode ring comprising a cylindrical resistor fitted on the inner surface of the insulating cylinder, the resistor is formed by laminating a plurality of cylinders in the axial direction with a conductive layer interposed therebetween, The conductive layer is formed by diffusion-bonding conductive films formed on end surfaces of the plurality of cylinders that are joined to each other, and the plurality of cylinders are each sintered and reduced in a sufficiently thin sheet shape. An electrode assembly comprising a conductive ceramic material It is resolved by grayed.

  In addition, the above-described problem is an electron microscope having an electrode ring disposed to face a sample to be irradiated with an electron beam, and the electrode ring has a first electrode on one end face facing the sample. An insulating cylinder having a second electrode formed on the other end face, a hollow hole serving as a passage path for the electron beam, one end face being connected to the first electrode, and the other end face being An electron microscope including a cylindrical resistor connected to the inner surface of the insulator and connected to the second electrode, wherein the resistor has an axial direction with a plurality of cylinders interposing a conductive layer therebetween. The conductive layers are formed by diffusion-bonding conductive films formed on end surfaces of the plurality of cylinders that are combined with each other, and the plurality of cylinders are each sintered in a sheet form.・ Reduced and sufficiently thin semiconductive ceramic It is solved by an electron microscope, characterized by comprising in wood.

  In addition, the above-described problem is an electrode ring disposed to face a sample that is irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface. An insulating cylinder having electrodes formed thereon, and a hollow hole serving as a passage path for the electron beam; one end face is connected to the first electrode, and the other end face is connected to the second electrode; And a cylindrical resistor fitted on the inner surface of the insulating cylinder, wherein the cylindrical resistor is manufactured by melting a semiconductive glass material to which a conductive material is added. This is solved by a method for manufacturing an electrode ring.

  In addition, the above-described problem is an electron microscope having an electrode ring disposed to face a sample to be irradiated with an electron beam, and the electrode ring has a first electrode on one end face facing the sample. An insulating cylinder having a second electrode formed on the other end face, a hollow hole serving as a passage path for the electron beam, one end face being connected to the first electrode, and the other end face being A cylindrical resistor connected to the second electrode and fitted in the inner surface of the insulator, wherein the cylindrical resistor is a semiconductive glass material to which a conductive material is added. This is solved by a manufacturing method of an electron microscope, which is manufactured by melting the above.

  In recent years, the degree of integration of various electronic devices has improved dramatically, but on the other hand, they are very sensitive to static electricity. The destruction of electronic devices due to static electricity and the deterioration of characteristics have been highlighted as a major problem, and semiconductive materials (ceramics and glass) are new materials effective for countermeasures against static electricity, and are materials with electrostatic diffusion characteristics. is there. Because it is difficult to charge static electricity and does not flow a large current, it is optimal for peripheral parts of electronic devices sensitive to static electricity and jig materials for manufacturing them. The electrode ring material for an electron microscope of the present invention has also been applied due to the feature that only a minute current flows when a high voltage is applied.

  According to the present invention, the hollow hole of the cylindrical resistor fitted into the insulating cylinder is used as the electron beam or secondary electron passage path, and the resistance value of the inner surface of the hollow hole is caused by the uneven conductivity of the resistor. The problem of variation does not occur, the electric field distribution around the axis center in the hollow hole can be made uniform, and desired trajectory control of the electron beam and secondary electrons is not hindered. As a result, the sample can be satisfactorily observed with an electron microscope.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows a plan view of one end face of an electrode ring 1 according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along the line [A]-[A] in FIG.

  The electrode ring 1 is formed on an insulating cylinder 5, a cylindrical resistor 4 fitted inside the insulating cylinder 5, a first electrode 2 formed on one end face, and the other end face. The second electrode 6 is provided.

  The insulating cylinder 5 has a cylindrical shape having a hollow hole 19 formed through the thickness direction (axial direction). The axial centers of the hollow hole 19 and the insulating cylinder 5 are the same. The insulating cylinder 5 is made of a ceramic material such as alumina, but is not limited thereto, and a nonmagnetic and insulating material can be used.

  The resistor 4 also has a cylindrical shape similar to that of the insulating cylinder 5 and has a hollow hole 3 formed through the thickness direction (axial direction). The axial centers of the hollow hole 3 and the resistor 4 are coincident. The thickness (axial dimension) of the resistor 4 is substantially equal to that of the insulating cylinder 5, and the thickness (outer diameter) of the resistor 4 is approximately equal to or slightly equal to the inner diameter of the hollow hole 19 of the insulating cylinder 5. small. The inner diameter of the hollow hole 3 of the resistor 4 is smaller than the inner diameter of the hollow hole 19 of the insulating cylinder 5.

  In the present embodiment, the resistor 4 is manufactured as follows. That is, the resistor 4 is obtained by adding a conductive material such as iron oxide to a quartz glass material and melting and solidifying it. The melted and solidified block of conductive glass thus configured is sliced thinly into a desired dimension (for example, thickness of 0.1 mm) by machining, and then the thickness dimension and flatness are finished by lapping. Since the resistor 4 manufactured by this method melts the glass, the additive can be uniformly dispersed inside and a substance having a very uniform electrical resistance can be created.

  As described above, the resistor 4 can stably obtain a large resistance value (for example, several GΩ to several TΩ) so as to moderate the potential change in the axial direction. The resistance value of the resistor 4 can be freely adjusted by adjusting the content ratio of the conductive material to be added.

  The resistor 4 is fitted in the hollow hole 19 of the insulating cylinder 5. The resistor 4 is pressed into the hollow hole 19 of the insulating cylinder 5, and the outer peripheral surface of the resistor 4 and the inner peripheral surface of the hollow hole 19 of the insulating cylinder 5 are in close contact with each other without a gap. The hollow hole 3 of the resistor 4 and the hollow hole 19 of the insulating cylinder 5 are aligned with each other. The insulating cylinder 5 and the resistor 4 are not limited to a cylindrical shape, and may be a rectangular tube shape.

  One end surface (lower end surface in FIG. 2) of the insulating cylinder 5 and one end surface (lower end surface in FIG. 2) of the resistor 4 are flush with each other, and one end surface of the electrode ring 1 (in FIG. 2). The first electrode 2 is formed on this end surface. The first electrode 2 is a conductive film formed on the entire surface of the one end face of the electrode ring 1 by sputtering or vapor deposition. The conductive film is made of a metal material such as copper or TiN. In addition, you may comprise the 1st electrode 2 by affixing conductor foil on the said one end surface.

  The other end face of the insulating ring 5 (upper end face in FIG. 2) and the other end face of the resistor 4 (upper end face in FIG. 2) are flush with each other and the other end face of the electrode ring 1 (in FIG. 2). The second electrode 6 is formed on this end surface. The second electrode 6 is a conductive film formed on the entire surface of the other end face of the electrode ring 1 by sputtering or vapor deposition. The conductive film is made of a metal material such as copper or TiN. In addition, you may comprise the 2nd electrode 6 by affixing conductor foil on the said other end surface.

  The electrode ring 1 configured as described above is disposed as a component part of an electron microscope between a ring-shaped objective lens 8 and a sample 9 as shown in FIG. The gap between the objective lens 8 and the sample 9 is, for example, about 2 to 3 mm. In the gap, the end surface on which the first electrode 2 is formed is opposed to the sample 9, and the end surface on which the second electrode 6 is formed is the objective lens. The electrode ring 1 is disposed so that the hollow hole 3 is positioned on the passage of the electron beam irradiated to the sample 9 toward the side 8. The gap between the end surface on which the first electrode film 2 is formed and the sample 9 is several tens μm to several hundreds μm.

  Above the objective lens 8, a multistage focusing lens, an electron gun, etc. (not shown) are arranged. The objective lens 8 functions as a lens for focusing and irradiating the sample 9 with the electron beam narrowed down by the focusing lens.

  A negative voltage is applied to the sample 9 from the power source 11, and the objective lens 8 is grounded. A negative voltage is applied from the power source 11 to the first electrode 2 of the electrode ring 1 to make it equipotential with the sample 9. The second electrode 6 of the electrode ring 1 is grounded.

  The case where the contact hole 10 formed in the sample 9 such as a semiconductor wafer is observed using the electron microscope according to the present embodiment configured as described above will be described. When the electron beam EB irradiated from an irradiation source such as an electron gun passes through the hollow hole 3 of the resistor 4 of the objective lens 8 and the electrode ring 1 and is irradiated to the contact hole 10 of the sample 9, the irradiated portion Secondary electrons are emitted from the surface.

  Here, since a negative voltage is applied to the sample 9, secondary electrons are emitted from the sample 9 so as to repel. At this time, since the negative voltage is also applied to the first electrode 6 formed on the end face side facing the sample 9 in the electrode ring 1 to make it equipotential with the sample 9, the sample 9 and the electrode ring facing this An electric field that prevents acceleration of secondary electrons emitted from the sample 9 is not generated between the lower end surface of 1 and the bottom surface of 1.

  As a result, the secondary electron emission locus a can be raised as compared with the conventional configuration shown in FIG. 10 (the configuration in which the electrode ring 1 is not interposed between the objective lens 8 and the sample 9) (FIGS. 5 and 5). 10 is not necessarily equal to each other in order to clarify each component). As a result, secondary electrons from the bottom of the contact hole 10 can be emitted without being absorbed by the side wall of the contact hole 10. This is particularly effective when the bottom of a contact hole having a high aspect ratio is observed as the semiconductor integrated circuit becomes finer.

  The emitted secondary electrons pass through the hollow hole 3 of the electrode ring 1. At this time, the secondary electrons are accelerated by a potential difference between the first and second electrodes 2 and 6 and are positively applied to a secondary electron detector (not shown). It is attracted to an electric potential and collides with a fluorescent screen applied to the surface of the secondary electron detector to be converted into light, which is amplified by a photomultiplier tube. This signal is further amplified and then displayed on the display device.

  Further, the first electrode 2 is formed on one end face side of the resistor 4 and the end face is electrically connected to the first electrode 2, and the second electrode 6 is formed on the other end face side. Since the end face is electrically connected to the second electrode 6, the second electrode 6 has a peak at the potential (−Vp) generated near the first electrode 2 on the inner surface of the hollow hole 3 of the resistor 4. An electric field is generated with a potential distribution that gradually decreases uniformly toward the side and approaches a potential of zero. Here, since the resistance value of the resistor 4 is very large (for example, several GΩ to several TΩ), the change in the potential distribution is uniform and gradual, and the electron beam or the emitted secondary electrons passing through the hollow hole 3. As a result, the lens aberration in the electron microscope can be reduced.

  Furthermore, in this embodiment, since the cylindrical resistor 4 is fitted into the hollow hole 19 of the insulating cylinder 5, the electron beam and the emission secondary electron passage path are surrounded by the resistance material. When the resistance film is formed on the inner surface of the hollow hole of the insulating cylinder (Patent Document 1), the electric field variation due to the non-uniform formation of the resistance film does not occur, and the electric field distribution around the axis center in the hollow hole 3 can be made uniform. It becomes easy to perform desired control of the electron beam by the objective lens 8 or the like.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the same component as the said 1st Embodiment, and the detailed description is abbreviate | omitted.

As the resistor 4 described above, a material in which a quartz material and iron oxide (Fe ₂ O ₃ ) are mixed and melted and solidified is used. Here, when the iron oxide as the conductive material is not mixed in a uniform distribution, a current easily flows in a portion having a small resistance (a portion where the conductive material is biased), and the axial center in the hollow hole 3 The electric field distribution around can be uneven. In particular, the resistance value of the resistor 4 is very large, from several GΩ to several TΩ, and the current tends to easily flow through a portion having a smaller resistance. There is a high possibility of non-uniform electric fields.

  In the second embodiment, as shown in FIG. 3, a plurality of (in this example, two layers) ring-shaped conductive layers 18 a that equalize the current flow around the axial center between both end faces of the resistor 17. , 18b are interposed. The pitch between the conductive layers 18a and 18b and the distance between each end face of the resistor 17 and the conductive layers 18a and 18b are substantially equal. The axial center of each conductive layer 18a, 18b and the axial center of the hollow hole 3 coincide.

  In the middle of the current path along the axial direction, the conductive layers 18a and 18b exist as portions having lower resistance than the other portions on the inner surface of the hollow hole 3, and the conductive layers 18a and 18b are formed in a ring shape around the axial center. Therefore, in the conductive layers 18a and 18b, current flows in the same way at any position in the circumferential direction (there is no bias due to the difference in the circumferential position). Therefore, an equal current flows around the axis center in the conductive layers 18a and 18b on the inner surface of the hollow hole 3, and an electric field with a uniform distribution is generated around the axis center. Even if an uneven current flow is formed around the axial center in the portions where the conductive layers 18a and 18b are not formed, the conductive layers 18a and 18b are made uniform around the axial center so that the inner surface of the hollow hole 3 is formed in the axial direction. As a whole of the current flowing along, the electric field variation around the axis center is suppressed.

  The resistor 17 according to this embodiment is obtained by stacking, for example, three cylinders 17a to 17c as shown in FIG. Each cylindrical body 17a-17c is obtained by uniformly mixing iron oxide with semiconductive glass and melting and solidifying it, and grinding the end surfaces so that the thicknesses of the cylindrical bodies 17a-17c are substantially equal to each other. Processed to the required dimensional accuracy. The thickness of the resistor 17 obtained by stacking the cylinders 17 a to 17 c is substantially equal to the thickness of the insulating cylinder 5. The outer diameters of the cylinders 17a to 17c are substantially equal to or slightly smaller than the inner diameter of the hollow hole 19 of the insulating cylinder 5. The inner diameters of the hollow holes of the cylinders 17a to 17c are substantially equal to each other and smaller than the inner diameter of the hollow hole 19 of the insulating cylinder 5.

  A conductive film 21a is formed on the end face of the cylindrical body 17a that is aligned with the cylindrical body 17b. Conductive films 21b and 21c are formed on both end faces of the cylindrical body 17b. A conductive film 21d is formed on each end face of the cylindrical body 17c. Each of the conductive films 21a to 21d is a copper film formed by, for example, a vapor deposition method or a sputtering method, but is not limited thereto, and any conductive material may be used. The thickness of each conductive film 21a-21d is about several micrometers.

  As shown in FIG. 4, the shaft core member 60 is passed through the hollow holes of the cylinders 17a to 17c, and the cylinders 17a to 17c are overlapped with each other, and heated in a vacuum furnace. In addition, by applying pressure in the axial direction, the conductive films 21a to 21d are diffusion-bonded (metal bonding by a bonding force acting between atoms on the metal surface). That is, the conductive layer 18a is obtained by diffusion bonding of the conductive film 21a and the conductive film 21b, and the conductive layer 18b is obtained by diffusion bonding of the conductive film 21c and the conductive film 21d.

  With such a laminated structure, the highly reliable resistor 17 having improved adhesion between the cylindrical bodies 17a to 17c made of a semiconductive glass material and the conductive films 21a to 21c and adhesion between the conductive films 21a to 21c, and can do. In addition, since no adhesive is used, there is no fear of deterioration of the age and dimensional accuracy due to the use of the adhesive.

  The resistor 17 obtained as described above is fitted into the hollow hole 19 of the insulating cylinder 5 as shown in FIG. One end face (lower end face in FIG. 3) of the insulating cylinder 5 and one end face (lower end face in FIG. 3) of the resistor 17 are flush with each other in the electrode ring 31 according to the second embodiment. One end face (lower end face in FIG. 3) is formed, and the first electrode 2 is formed on this end face as in the first embodiment. The other end face of the insulating cylinder 5 (upper end face in FIG. 3) and the other end face of the resistor 17 (upper end face in FIG. 3) are flush with each other, and the other end face of the electrode ring 31 (in FIG. 3). The second electrode 6 is formed on the end surface as in the first embodiment.

  In the above example, the conductive films 21a to 21d are formed on the mating surfaces of the cylinders 17a to 17c, respectively, and then the resistor 17 is obtained using diffusion bonding between the conductive films 21a to 21d. The conductor foil may be sandwiched and laminated between the cylinders 17a to 17c via an adhesive.

  Further, the number of conductive layers is not limited to two, but may be one layer, three layers, four layers or more. In addition, it is preferable that the conductive layers are arranged at an equal pitch in the axial direction so that portions where current easily flows are arranged in the axial direction. In the case of one layer, it is preferable that the resistor 17 is disposed at a substantially half position in the thickness direction (axial direction).

  FIG. 6 shows an electrode ring 40 according to a third embodiment of the present invention. In this embodiment, a semiconductive ceramic material is used, and in the previous proposal, a block material of about several tens mm to several hundred mm was manufactured by sintering using a reduction reaction in a special atmosphere. In this embodiment, a semiconductor electroceramic material having a uniform resistance value is adopted by carrying out a sintering reduction with a sheet sufficiently thinner than 1 mm, for example, 0.1 mm, and proceeding the reduction reaction sufficiently to the inside. Thus, lapping is performed on the upper and lower surfaces of the material sintered in the form of a sheet to align the thickness dimension and finish the flatness. In the present invention, a sufficiently thin sheet means that the sheet is thin enough to be sufficiently reduced to the center. Accordingly, the thickness of the sheet may be 1 mm or more as described above.

  In this way, as shown in FIG. 6, in the electrode ring 40 of the present embodiment, the four-stage sheet-like resistance rings 41a, 41b, 41c, and 41d are overlapped. In this manufacturing method, as shown in FIG. 7, the semiconductive ceramic materials 41a, 41b, 41c, and 41d are inserted into the jig 60 in the center hole in substantially the same manner as the above semiconductive glass material, and heated and pressurized to obtain FIG. The configuration shown is obtained. Again, buffer layers 44a, 44b, and 44c are formed between the resistance ring materials 41a, 41b, 41c, and 41d, and this is performed by depositing copper (43a to 43f) in the same manner as in the second embodiment. The resistor 41 shown in FIG. 6 can be obtained by being inserted into the jig 60 and heated and pressed.

  In this embodiment, since sintering and oxidation are performed with a very thin dimension of 0.1 mm, each resistance ring is sufficiently reduced to the inner center, and each resistor has a resistance value significantly higher than the conventional one. Can be made uniform.

  FIG. 8 is a chart showing the change with time of the resistance value of the resistor according to each embodiment of the present invention. The above-mentioned −Vp is 1 kV, and changes according to each embodiment are shown. In the case of a resistor cut out from a conventional ceramic sintered body of several tens to several hundreds of mm, it is indicated by a. In contrast, the resistance value increases with time, whereas in the resistor formed by adding and melting the iron oxide material to the quartz material according to the first embodiment of the present invention, as shown by b, from the beginning Even after 60 minutes, the resistance value hardly changed. In addition, when the resistance rings made of the semiconductive ceramic according to the third embodiment of the present invention are each sufficiently thin and laminated in multiple layers as described above, the first twentieth is slightly increased as shown by c. However, it hardly changes after that. There is a great difference in stability between the conventional characteristic a and the characteristic c according to the embodiment of the present invention. Even if it is made of the same semiconductive ceramic, it is cut out from a sintered body block of several tens mm to several hundred mm and cut to a desired thickness, but it is sintered in a special atmosphere as described above. Is not reduced to the center. For this reason, it increases as shown by a and is unstable. On the other hand, in the present embodiment, a very thin molded body of 0.1 mm is sintered and reduced, so that it is sufficiently reduced to the center.

  FIG. 9 shows the change in resistance value due to the load voltage (−Vp). As the voltage changes from 0 to 1,000 V, the resistance value increases as a result of cutting from a conventional sintered block of several tens to several hundred mm. Resistive ceramics show the characteristic that after a little increase from 0 volts, the resistance ceramic slightly decreases to a point exceeding 200 V and then increases. On the other hand, in the quartz glass material added with iron oxide according to the first embodiment of the present invention, as shown by b, it is almost constant from 0V to 1000V. Next, in the third embodiment of the present invention in which the ring resistors made of high resistance ceramics are laminated in multiple layers, as shown by c, the voltage increases slightly when it is small, but is constant thereafter. This is also because, as described above, it was formed into a thin sheet of 0.1 mm and sintered and oxidized, so that it was sufficiently reduced to the inside and had the characteristics of a uniform material.

  In the embodiment of the present invention, as described above, both the resistance value change with time and the resistance value change characteristic due to the load voltage are significantly superior to those of the prior art.

  As mentioned above, although each embodiment of this invention was described, of course, this invention is not limited to these, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, in the first embodiment described above, iron oxide is added to a quartz material and melted to obtain a semiconductive glass material. However, the conductive material is not limited to iron oxide, and other metal oxides and particulates are used. It may be molybdenum.

  Moreover, in the above 2nd Embodiment, although the sheet-like ring material of the semiconductive glass material was made into 3 layers, of course, more or 2 layers may be sufficient. In short, the conductive material is mixed with the quartz material and melted. However, the concentration varies depending on the melting method or the state of stirring, and if the solidified as it is, a uniform voltage gradient from the upper end surface to the lower end surface of the resistor is produced. Can't get. Therefore, the number of buffer layers (Cu layer in the above embodiment), that is, the number of stages of the resistance ring body may be increased or decreased in accordance with the unevenness of the concentration. Although the above-described concentration unevenness is alleviated by the buffer layer, the buffer layer is not limited to copper but may be other metals.

  In the third embodiment, four resistance rings formed by sintering a semiconductive ceramic material are stacked. However, this number is the same as described above, and is not limited thereto.

It is the top view seen from the one end surface side of the electrode ring which concerns on the 1st Embodiment of this invention. It is sectional drawing of the [A]-[A] line direction in FIG. It is sectional drawing of the electrode ring which concerns on the 2nd Embodiment of this invention. FIG. 4 is a cross-sectional view showing a method of manufacturing a laminated body of semiconductive glass material resistance rings according to the second embodiment. FIG. 5 is an enlarged cross-sectional view schematically showing the main part of the electron microscope according to the embodiment of the present invention. FIG. 6 is a sectional view of an electrode ring according to a third embodiment of the present invention. FIG. 7 is a cross-sectional view showing a method for manufacturing a laminate of semiconductive ceramic material rings according to a third embodiment. FIG. 8 is a graph showing changes over time in the resistance values of the resistors of the conventional example, the first embodiment, and the third embodiment. FIG. 9 is a graph showing voltage characteristics of the resistors according to the conventional example, the first embodiment, and the third embodiment. FIG. 10 is an enlarged cross-sectional view schematically showing a main part of a conventional electron microscope. It is sectional drawing of the electrode ring of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electrode ring, 2 ... 1st electrode, 3 ... Hollow hole, 4 ... Resistor, 5 ... Insulating cylinder, 6 ... 2nd electrode, 8 ... Objective lens, 9 ... Sample, 10 ... Contact hole, 17 ... Resistor, 18a, 18b ... conductive layer, 21a-21d ... conductive film, 31, 40 ... electrode ring, 41 ... resistor, 41a-41d ... resistance ring, 43a-43f ... conductive film, 44a-44d ... conductive film

Claims (14)

An electrode ring disposed opposite to a sample to be irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface A cylinder,
A cylinder having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulating cylinder An electrode ring comprising a body resistor,
An electrode ring, wherein the cylindrical resistor is made of a semiconductive glass material including a conductive material.   The electrode ring according to claim 1, wherein the glass material is quartz.   The electrode ring according to claim 1, wherein the conductive material is iron oxide.   The electrode ring according to claim 1, wherein at least one ring-shaped conductive layer is interposed in a portion between the both end faces of the resistor.   The resistor is formed by laminating a plurality of cylinders in the axial direction with the conductive layer interposed therebetween, and the conductive layers are respectively formed on end surfaces of the plurality of cylinders that are aligned with each other. The electrode ring according to claim 4, wherein the electrodes are formed by diffusion bonding. An electron microscope having an electrode ring disposed opposite to a sample to be irradiated with an electron beam,
The electrode ring is
An insulating cylinder in which a first electrode is formed on one end surface facing the sample and a second electrode is formed on the other end surface;
A cylindrical hole having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulator; In an electron microscope comprising a resistor,
2. The electron microscope according to claim 1, wherein the cylindrical resistor is made of a semiconductive glass material including a conductive material. An electrode ring disposed opposite to a sample to be irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface A cylinder,
A cylinder having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulating cylinder. An electrode ring comprising a body resistor,
The resistor is formed by laminating a plurality of cylinders in the axial direction with a conductive layer interposed therebetween, and the conductive layers are formed between conductive films formed on end surfaces of the plurality of cylinders that are aligned with each other. And a plurality of cylinders each made of a semiconductive ceramic material sintered and reduced in a sufficiently thin sheet form. An electron microscope having an electrode ring disposed opposite to a sample to be irradiated with an electron beam,
The electrode ring is
An insulating cylinder in which a first electrode is formed on one end surface facing the sample and a second electrode is formed on the other end surface;
A cylindrical hole having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulator; In an electron microscope comprising a resistor,
The resistor is formed by laminating a plurality of cylinders in the axial direction with a conductive layer interposed therebetween, and the conductive layers are formed between conductive films formed on end surfaces of the plurality of cylinders that are aligned with each other. An electron microscope characterized in that the plurality of cylinders are made of a sufficiently thin semiconductive ceramic material sintered and reduced in a sheet form. An electrode ring disposed opposite to a sample to be irradiated with an electron beam, wherein a first electrode is formed on one end surface facing the sample, and a second electrode is formed on the other end surface A cylinder,
A cylinder having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulating cylinder In a method of manufacturing an electrode ring comprising a body resistor,
The manufacturing method of an electrode ring, wherein the cylindrical resistor is manufactured by melting a semiconductive glass material to which a conductive material is added.   The method for manufacturing an electrode ring according to claim 9, wherein the glass material is quartz.   The method for manufacturing an electrode ring according to claim 9, wherein the conductive material is iron oxide.   The electrode ring manufacturing method according to claim 9, wherein at least one ring-shaped conductive layer is interposed between the both end faces of the resistor.   The resistor has a plurality of cylinders stacked in the axial direction with the conductive layer interposed therebetween, and is pressed, and the conductive layers are formed on end surfaces of the plurality of cylinders that are aligned with each other. The method for producing an electrode ring according to claim 12, wherein the conductive films are diffusion-bonded to each other. An electron microscope having an electrode ring disposed opposite to a sample to be irradiated with an electron beam,
The electrode ring is
An insulating cylinder in which a first electrode is formed on one end surface facing the sample and a second electrode is formed on the other end surface;
A cylindrical hole having a hollow hole serving as a passage path for the electron beam, having one end face connected to the first electrode and the other end face connected to the second electrode, and fitted into the inner surface of the insulator; In an electron microscope manufacturing method comprising a resistor,
The method of manufacturing an electron microscope, wherein the cylindrical resistor is manufactured by melting a semiconductive glass material to which a conductive material is added.

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