JP2007165232A - Charged particle beam device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charged particle beam device in which variation of atmospheric pressure does not affect accuracy of the device and which has a vacuum exhaustion system structure in which vibration of a pump is not transmitted to a charged particle beam device main body, and provide a vacuum suction passage for the charged particle beam device. <P>SOLUTION: The charged particle beam device or the vacuum suction passage of the charged particle beam device is composed of a charged particle beam device main body including an electrooptical system which irradiates electron beams or ion beams on a target, a vacuum exhaustion system provided with a suction pump which makes vacuum inside the charged particle beam device main body, a suction passage communicating the charged particle beam device main body with the vacuum exhaustion system, a vibration preventing part intercalated in the suction passage, and a flexible passage member fixed in the vibration preventing part. A shrinkage preventing means is provided for preventing the flexible passage member from shrinking by suction of the vacuum exhaustion system in a direction where the charged particle beam device main body and the vacuum exhaustion system are pulled from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electron beam drawing apparatus that draws a circuit pattern or the like on a semiconductor wafer using an electron beam, an electron microscope that obtains an enlarged image of an object using an electron beam, and an enlarged image of an object using an ion beam. The present invention relates to an ion beam apparatus for obtaining or processing an object.

  The vacuum evacuation device is equipped with an electron beam or ion beam generating mechanism inside, and is a key point in the design of charged particle beam devices such as an electron beam drawing device, an electron microscope, etc. One. An electron beam drawing apparatus is disclosed in, for example, Japanese Patent Laid-Open No. 2000-357484 (Patent Document 1).

  The charged particle beam part of the charged particle beam system must be kept in a high vacuum so that the high energy electron beam or ion beam will not collide with atmospheric molecules and lose kinetic energy or bend the orbit. .

  For this purpose, turbo molecular pumps and ion pumps are mainly used as vacuum exhaust devices because of the demand for the ultimate vacuum required. These vacuum pumps are connected to the charged particle device main body by a tube (vacuum piping) kept airtight with an O-ring, a gasket, or the like, and keep the charged particle device main body in operation at a high vacuum.

  The turbo molecular pump is a vacuum pump that rotates turbine blades to eject air molecules. When a turbo molecular pump is employed as the vacuum device of the charged particle device, the exhaust speed is remarkably higher than that of the ion pump, so that it takes a short time to exhaust the device to a high vacuum region. It is economical because it can be quickly restored after the inside of the apparatus is returned to the atmospheric pressure for maintenance or the like, and the apparatus can be operated for a long time. However, the turbo molecular pump has a weak point in which vibration is generated when the pump is operated due to the structure in which the turbine mechanically rotates. The vibration generated by the pump is transmitted to the charged particle beam apparatus main body, which adversely affects accuracy.

  For this reason, many charged particle beam apparatuses employing a turbo molecular pump take measures to reduce vibration by installing the turbo molecular pump on a vibration-proof rubber or the like. At this time, the vacuum pipe between the turbo molecular pump and the charged particle beam main body must be connected using a flange having a movable part such as a bellows. This is because, when connected by a vacuum duct such as a normal steel pipe, the vibration of the pump is transmitted to the main body through the duct.

However, the pump-body evacuation system using the bellows has a weak point that is affected by fluctuations in atmospheric pressure around the device. Normally, a force acts in a direction in which the bellows is contracted in the vacuum pipe having the bellows portion due to atmospheric pressure. In order to support the bellows against this force, a support rod or the like that prevents the bellows from contracting is often installed around the bellows, but in the case of a charged particle beam device, the support rod cannot be easily added. This is because the support rod becomes a new vibration transmission path and transmits the vibration of the pump to the main body. For this reason, the force acting between the pump and the main body is supported by the rigidity of the tower that fixes the apparatus main body and the pump. Normally, the atmospheric pressure is 1 atm (about 1013 hectopascals), and in the case of a bellows having a cross-sectional area of 100 square centimeters, a force of about 103 kilogram weight (about 1013 newtons) always acts as a force for contracting the bellows.
Here, the fluctuation of the atmospheric pressure around the apparatus due to the influence of a low atmospheric pressure or the like is considered. Although the atmospheric pressure fluctuates by about 10 percent at the maximum depending on the weather, the contracting force varies by about 10 percent because the force to contract the bellows is proportional to the atmospheric pressure. In the case of the upper bellows, the variation is about 10 kilogram weight (about 101 newtons). Originally, this contraction force is supported by the rigidity of the charged particle beam device main body and the tower where the pump is mounted. Therefore, the force acting between the charged particle beam device main body and the tower is changed by the contraction force changing. It will fluctuate and both will be deformed. In particular, since the charged particle beam apparatus main body is a part that forms the optical system of the charged particle beam, the deformation of the main body fluctuates the trajectory of the charged particle beam and deteriorates the beam irradiation position. This causes the accuracy of the apparatus to deteriorate.

JP 2000-357484 A

  In view of the above problems, the present invention provides a charged particle apparatus and a charged particle beam apparatus having a vacuum exhaust system structure in which fluctuations in atmospheric pressure do not affect apparatus accuracy and vibrations of the pump are not transmitted to the charged particle apparatus main body. It is an object of the present invention to provide a vacuum suction path.

  The present invention relates to a charged particle beam apparatus main body including an electron optical system that irradiates a target with an electron beam or an ion beam, a vacuum exhaust system provided with a suction pump for evacuating the charged particle beam apparatus main body, and a charged particle beam apparatus main body. A charged particle beam device or a vacuum suction path of a charged particle beam device having a suction path communicating with the vacuum exhaust system, a vibration isolating portion interposed in the suction path, and a flexible passage member provided in the vibration isolating portion Further, the present invention is characterized in that a contraction preventing means for suppressing contraction of the flexible passage member in a direction in which the charged particle beam apparatus main body and the vacuum exhaust system are attracted by suction of the vacuum exhaust system is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration of a vacuum pump is interrupted | blocked, and the charged particle beam apparatus by which the beam irradiation position precision by atmospheric pressure fluctuation does not deteriorate, and the vacuum suction path | route of a charged particle beam apparatus can be provided.

  FIG. 1 is a longitudinal sectional view showing a schematic configuration of an electron beam lithography apparatus which is a kind of a charged particle beam apparatus as an example of a known example for illustrating an embodiment of the present invention.

  In FIG. 1, the electron beam drawing apparatus main body 1 and the vacuum exhaust system 2 communicate with each other through a vacuum suction path having a bellows 108.

  The electron beam drawing apparatus main body 1 includes a mirror body 102 and a target chamber 106 in which an electron optical system having a function to generate and converge an electron beam is placed. The mirror body 102 is placed on the upper part of the target chamber 106, and is fastened firmly and tightly by a connecting means including a bolt.

  The electron beam 105 generated by the electron gun 101 placed in the mirror body 102 is accelerated to an energy of several tens of kilovolts by the potential difference from the anode, and is shaped, reduced and projected by the diaphragm 103 and the electromagnetic lens 104, and then on the target 107. Draw a circuit pattern or the like.

  The vacuum exhaust system 2 has a turbo molecular pump 111 that is a vacuum pump. The suction path of the vacuum suction path that communicates the mirror body 102 and the vacuum exhaust system 2 is provided with a target bellows 108 that does not transmit vibration generated by the turbo molecular pump 111 of the vacuum pump.

  The tower 110 that supports the vacuum exhaust system 2 includes a vacuum pipe 109, a turbo molecular pump 111, and a vibration isolator 112. An anti-vibration device 112 provided below the tower 110 supports the turbo molecular pump 111 in an anti-vibration manner.

  The vacuum of the mirror body 102 is maintained so that the degree of vacuum is increased by the suction of the turbo molecular pump 111 and the rotary pump 113.

  FIG. 3 is a reference diagram for comparison with the present invention, and shows a part of the mirror body 301 and the vacuum suction path of the electron beam drawing apparatus main body.

  The electron beam passes through the mirror body 301 as indicated by an arrow 308. A vacuum pump (not shown) is installed at the end of an arrow 314 representing vacuum exhaust through the duct 304. A vibration isolator is interposed in the suction path of the vacuum suction path including the duct 304.

  The vibration isolator has a flexible bellows 303, which is a flexible passage member, hard flanges 302 and 305, and an airtight O-ring 313.

  When atmospheric pressure changes due to suction by the vacuum pump, the mirror body 301 of the electron beam drawing apparatus body is slightly deformed so as to be pushed in the direction of the duct 304. This is because the bellows 303 contracts by attracting the mirror body 301 and the vacuum exhaust system 2 by the differential pressure between the vacuum and the atmospheric pressure, and the contraction force acts on the mirror body 301.

  In the present invention, the deformation of the mirror body 301 is suppressed without generating the contraction force.

  The embodiment shown in FIG. 2 will be described.

  The mirror body 201 of the electron beam drawing apparatus main body communicates with the vacuum pump side 214 of the evacuation system via the suction passage duct 204 of the vacuum suction path. Furthermore, a vibration isolator is provided in the suction path. The vibration isolator has a flexible bellows 203 that is a flexible passage member, hard flanges 202 and 205, and an airtight O-ring 213.

  The vibration isolator is fastened to the mirror body 201 and the duct 204 in a robust and airtight manner by connecting means including bolts. A flange 202 is fastened to the mirror body 201, and a flange 205 is fastened to the duct 204.

  The mirror body 201 is provided with a shrinkage prevention body (shrinkage prevention means) on the opposite side of the suction path including the vibration isolator. By this contraction prevention means, contraction of the flexible bellows 203 which is a flexible passage member can be suppressed.

  The anti-shrinkage body includes a flexible bellows 210 that is a flexible member, rigid flanges 209 and 211, an airtight O-ring 213, and a closure lid 212.

  The vibration isolator is fastened to the mirror body 201 in a robust and airtight manner by a connecting means including a bolt. A flange 209 is fastened to the mirror body 201, and a lid 212 is fastened to the flange 211.

  Then, a support 206 is placed so as to extend through the mirror body 201 and between the flange 205 of the vibration isolator and the flange 211 of the shrinkage prevention body. Since one end of the support 206 is screwed to the flange 205 and the other end is screwed to the flange 211, the support 206 is attached to the flanges 205 and 211 without falling off.

  The adjustment mechanism 207 is provided in the middle of the support 206. The adjustment mechanism 207 adjusts the length of the support 206 so that the tension on the flanges 205 and 211 can be adjusted.

  The support 206, the adjusting mechanism 207, the duct 204, and the flanges 205 and 211 are not in contact with the mirror body 201 of the electron beam drawing apparatus main body, and can be freely moved within the movable range of the bellows 203 and 210. .

  Even if the atmospheric pressure fluctuates due to the suction of the vacuum pump, the support 206 is placed so as to stretch between the flange 205 of the vibration isolator and the flange 211 of the anti-shrinkage body. The contraction of the bellows 203 of the flexible passage member is suppressed in the direction in which the vacuum exhaust system is attracted.

  That is, when the atmospheric pressure in the mirror body 201 becomes a vacuum, the bellows 203 acts so as to contract in the direction in which the mirror body 201 and the vacuum exhaust system are attracted. At the same time, a contracting force acts on the bellows 210 of the contraction inhibitor body. Since the forces acting on the bellows 203 and the bellows 210 have the same strength and opposite directions, they cancel each other through the support rod 206 and the contraction of the bellows 203 is prevented. For this reason, the atmospheric pressure fluctuation does not affect the drawing accuracy of the electron beam drawing apparatus.

  Another embodiment shown in FIG. 5 will be described.

  In this embodiment, the passage of the electron beam is performed well without any trouble.

  In the previous embodiment (the embodiment shown in FIG. 2), since the support 206 is present near the electron beam 208, there is a possibility that the passage of the electron beam may be impaired, and this problem is solved.

  As shown in FIG. 5, the mirror body 501 of the electron beam drawing apparatus main body communicates with the vacuum pump side 514 of the vacuum exhaust system via the duct 514 of the suction path of the vacuum suction path. Furthermore, a vibration isolator is provided in the suction path.

  The vibration isolator has a flexible bellows 503 that is a flexible passage member, hard flanges 502 and 505, and an airtight O-ring 513.

  The vibration isolator is fastened to the mirror body 501 and the duct 504 in a robust and airtight manner by a connecting means including a bolt. A flange 502 is fastened to the mirror body 501, and a flange 205 is fastened to the duct 514.

  The mirror body 501 is provided with a shrinkage prevention body (shrinkage prevention means) at a position moved 120 ° from where the suction path including the vibration isolator is located. This shrinkage prevention body is provided on both sides of the suction path including the vibration isolator.

  By this contraction prevention means, contraction of the flexible bellows 510 that is the flexible passage member can be suppressed.

  The shrinkage prevention body includes a flexible bellows 510 that is a flexible member, rigid flanges 509 and 511, an airtight O-ring 513, and a closing lid 512.

  The vibration isolator is fastened to the mirror body 501 in a robust and airtight manner by connecting means including a bolt. A flange 509 is fastened to the mirror body 501, and a lid 512 is fastened to the flange 511.

  A support 506 is placed so as to extend through the mirror body 501 between the flange 505 of the vibration isolator and the flange 511 of the anti-shrinkage body. Since one end of the support 506 is screwed to the flange 505 and the other end is screwed to the flange 511, the support 506 is attached to the flanges 505 and 511 without falling off.

  Moreover, the support 506 is also provided between both contraction inhibitor bodies. Each of the vibration isolator and the both anti-shrinkage body is provided so that two supports 506 are stretched. For this reason, the three supports 506 are present at positions away from the center of the mirror body 501 through which the electron beam 508 passes. Thereby, the passage of the electron beam 508 is not hindered by the support 506, and the drawing is performed without being impaired.

  The adjustment mechanism 507 is provided in the middle of the support 506. By providing the two adjusting mechanisms 507 on one support 506, the straight support 206 can be used without bending the support 506, so that the manufacture is easy.

  Another embodiment shown in FIG. 4 will be described.

  In this embodiment, a short support can be used without penetrating the mirror body.

  In the previous embodiment shown in FIGS. 2 and 5, since the support penetrates through the lens body, there is a problem that the structure is complicated, the assembly is not good, and a long support is required. It is a thing.

  As shown in FIG. 4, the mirror body 401 of the electron beam drawing apparatus main body communicates with the vacuum pump side 414 of the vacuum exhaust system via the ducts 415 and 416 of the suction path of the vacuum suction path. Furthermore, a vibration isolator is provided in the suction path. In the middle of the suction path, a vibration isolator that cuts off the transmission of the vibration of the vacuum pump is provided.

  The vibration isolator is connected to the central base body 404 connected so that the vacuum exhaust system side of the suction path communicates with the flexible body, provided at one end of the central base body 404, and connected to the mirror body 401 side. It has a bellows 403 as a passage member and a bellows 410 as a flexible member for preventing shrinkage provided at the other end of the central base body 404 opposite to the bellows 403.

  A duct 416 that communicates with the center base 404 is integrally formed. The duct 416 is provided in a direction intersecting with the mounting direction of the bellows 403 and 410.

  The bellows 403 of the flexible passage member has hard flanges 402 and 405 and an airtight O-ring 413 on both ends.

  The bellows 410, which is a flexible member, has hard flanges 409 and 411 and airtight O-rings 413 on both ends.

  The flange 405 of the bellows 403 of the flexible passage member is fastened to the central base body 404 by a connecting means including a bolt in a robust and airtight manner. Another flange 405 of the bellows 403 is fastened firmly to the duct 415 provided on the side of the mirror body 401 by connecting means including bolts in a robust and airtight manner. The opposite side of the duct 415 is fastened to the mirror body 401 with connection means including bolts in a robust and airtight manner.

  The flange 409 of the bellows 410 of the flexible member is fastened to the central base body 404 with a connection means including a bolt in a robust and airtight manner. A closing lid 412 is fastened to another flange 411 of the bellows 410 with a connecting means including a bolt in a robust and airtight manner.

  The support 406 is placed so as to stretch between the flange 402 of the bellows 403 of the flexible passage member and the flange 411 of the bellows 410 of the flexible member.

  Since the vibration isolator having such a configuration does not allow the support rod 406 to penetrate the mirror body 401, the length of the support rod 406 can be shortened as compared with the embodiments shown in FIGS. Further, since the support rod 406 is not penetrated into the mirror body 401, the configuration is simple and easy to assemble.

  Further, since the support 406 is not penetrated into the mirror body 401, the electron beam 408 passing through the mirror body 401 is not hindered.

  According to the above-described embodiment, in an electron beam or ion beam device such as an electron beam drawing device, a high-speed turbo molecular pump is used as an exhaust device, vibration is not transmitted to the charged particle device body, and due to atmospheric pressure fluctuations An inexpensive and highly accurate charged particle device without deterioration in accuracy can be provided.

  FIG. 6 is another embodiment corresponding to FIG. 4, and has a configuration in which the support 606 of the shrinkage prevention means is arranged apart from the central base body 604. This embodiment is advantageous in terms of mounting because the support 606 is outside.

  In addition, the mirror body 601, the suction path ducts 615 and 616 of the vacuum suction path, the vacuum pump side 614 of the vacuum exhaust system, the mirror body 601, the flexible passage member bellows 603, the flexible member bellows 610, and the flange 602 605 and the O-ring 613 are common to the embodiment of FIG. Further, the flanges 609 and 611, the electron beam 608, and the closing lid 612 are also common to the embodiment of FIG.

  FIG. 7 shows another embodiment corresponding to FIG. 2, and has a configuration in which a support 706 of the anti-shrinkage means is arranged apart from the mirror body 702. This embodiment is advantageous in terms of mounting because the support 706 is outside. Since the support 706 is curved, it is necessary to increase the strength.

  The duct 704, the vacuum pump side 714, the bellows 703, the flanges 702 and 705, the O-ring 713, the bellows 710, the flanges 709 and 711, the lid 712, and the adjusting mechanism 707 are the same as those in the embodiment of FIG.

It is a longitudinal cross-sectional view which concerns on the Example of this invention, and shows the outline | summary of an electron beam drawing apparatus. It is a principal part expanded sectional view concerning the Example of this invention. It is a reference figure compared with this invention. It is a principal part expanded sectional view concerning the other Example of this invention. It is a principal part expanded sectional view concerning the other Example of this invention. FIG. 5 is an enlarged cross-sectional view of a main part in which the support shown in FIG. FIG. 4 is an enlarged cross-sectional view of a main part in which the support shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 107 ... Target, 208 ... Electron beam (electron beam), 1 ... Charged particle beam apparatus main body containing an electron optical system, 111 ... Turbo molecular pump (suction pump), 204 ... Duct (suction path), 203 ... Bellows (vibration isolation) Part: flexible passage member), 206: support (shrinkage prevention means), 210 ... bellows (shrinkage prevention means).

Claims (12)

A charged particle beam apparatus body including an electromagnetic optical system for irradiating a target with an electron beam or an ion beam;
An evacuation system equipped with a suction pump for evacuating the charged particle beam apparatus body;
A suction path communicating the charged particle beam device main body and the vacuum exhaust system;
A vibration isolator interposed in the suction path;
In the charged particle beam device having a flexible passage member provided in the vibration isolator,
A charged particle beam apparatus comprising: a contraction preventing unit that suppresses contraction of the flexible passage member in a direction in which the charged particle beam apparatus main body and the vacuum exhaust system are attracted by suction of the vacuum exhaust system. . A target room where the target is placed,
A mirror provided in an upper part of the target chamber and provided with an electron optical system for irradiating the target with an electron beam or an ion beam;
A vacuum exhaust system tower equipped with a vacuum pump including a turbo molecular pump and vacuum piping,
A suction path communicating the inside of the evacuation system and the body;
A vibration isolator interposed in the suction path;
A flexible passage member provided in the vibration isolator;
A charged particle beam apparatus comprising: a contraction preventer body that suppresses contraction of the flexible passage member in a direction in which the mirror body and the vacuum exhaust system are attracted by suction of the vacuum exhaust system. A target room where the target is placed,
A mirror provided in an upper part of the target chamber and provided with an electron optical system for irradiating the target with an electron beam or an ion beam;
A vacuum exhaust system tower equipped with a vacuum pump including a turbo molecular pump and vacuum piping,
A suction path communicating the inside of the evacuation system and the body;
A vibration isolator interposed in the suction path;
A flexible passage member included in the vibration isolator, and a rigid flange;
A contraction preventer body that suppresses contraction of the flexible passage member in a direction in which the mirror body and the vacuum exhaust system are attracted by suction of the vacuum exhaust system;
A flexible member included in the anti-shrinkage body, and a rigid flange;
A charged particle beam device comprising: a support member placed so as to be stretched between a flange of the vibration isolator and a flange of the shrinkage prevention body. The charged particle beam device according to claim 3.
The charged particle beam apparatus, wherein the flexible passage member and the flexible member are formed of a flexible bellows cylinder. The charged particle beam device according to claim 3.
The charged particle beam device according to claim 1, wherein the shrinkage prevention body is disposed on the opposite side of the vibration isolator. The charged particle beam device according to claim 3.
One vibration isolator and two anti-shrinkage bodies are arranged in the mirror body at approximately equal intervals;
A charged particle beam apparatus comprising a support placed so as to be stretched between the flanges of the adjacent shrinkage prevention bodies. In the charged particle beam device according to any one of claims 3 to 6,
A charged particle beam apparatus comprising an adjustment mechanism for adjusting a length of the support. In the charged particle beam device according to any one of claims 3 to 6,
A charged particle beam apparatus comprising a closing lid that is detachably attached to a flange of the shrinkage prevention body. A target room where the target is placed,
A mirror provided in an upper part of the target chamber and provided with an electron optical system for irradiating the target with an electron beam or an ion beam;
A vacuum exhaust system tower equipped with a vacuum pump including a turbo molecular pump and vacuum piping,
A suction path communicating the inside of the evacuation system and the body;
A vibration isolator that interrupts transmission of vibration provided in the middle of the suction path;
The vibration isolator is a central base connected to communicate with the vacuum exhaust system side of the suction path, and a flexible passage provided at one end of the central base and connected to the mirror side A member, a flexible member for preventing contraction provided at the other end of the central base opposite to the flexible passage member, the flexible passage member by the suction of the vacuum exhaust system, and the flexible member A charged particle beam device characterized by having a support for preventing contraction in the direction of attracting each other. The charged particle beam apparatus according to claim 9, wherein
A charged particle beam apparatus comprising a closure lid that is detachably attached to a hard flange provided on an outer end side of the flexible member. A charged particle beam apparatus main body including an electron optical system for irradiating a target with an electron beam or an ion beam;
An evacuation system equipped with a suction pump for evacuating the charged particle beam apparatus body;
A suction path communicating the charged particle beam device main body and the vacuum exhaust system;
A vibration isolator interposed in the suction path;
In a vacuum suction path of a charged particle beam device having a flexible passage member provided in the vibration isolator,
A charged particle beam apparatus comprising: a contraction preventing unit that suppresses contraction of the flexible passage member in a direction in which the charged particle beam apparatus main body and the vacuum exhaust system are attracted by suction of the vacuum exhaust system. Vacuum suction path. A target room where the target is placed,
A mirror provided in an upper part of the target chamber and provided with an electron optical system for irradiating the target with an electron beam or an ion beam;
A vacuum exhaust system tower equipped with a vacuum pump including a turbo molecular pump and vacuum piping,
A suction path communicating the inside of the evacuation system and the body;
A vibration isolator that interrupts transmission of vibration provided in the middle of the suction path;
The vibration isolator is a central base connected to communicate with the vacuum exhaust system side of the suction path, and a flexible passage provided at one end of the central base and connected to the mirror side A member, a flexible member for preventing contraction provided at the other end of the central base opposite to the flexible passage member, the flexible passage member by the suction of the vacuum exhaust system, and the flexible member A vacuum suction path for a charged particle beam apparatus, comprising a support for preventing the conductive member from contracting in a direction of attracting each other.

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