Optical device and charged particle beam device

Abstract

To provide a technique for preventing inflow of gas containing pollutant into a container and outflow of inert gas to the outside of the container.SOLUTION: An optical device 100 comprises: a light irradiation device 1 capable of emitting light 3; a plurality of container parts 13, 21, 31; a gas supply port 22; and a gas suction port 32. The plurality of container parts 13, 21, 31 separate a purge space 20 to which inert gas is supplied, a gas suction space 30 for sucking existing gases, and a device-outside space 80 from each other. The purge space 20 is used as an optical path of the light 3. An optical element 4b is provided in the purge space 20. Inert gas is supplied from the gas supply port 22 to the purge space 20 and gases existing in the gas suction space 30 is sucked through the gas suction port 32. Atmospheric pressure in the gas suction space 30 can be thereby controlled to be lower than atmospheric pressure in the purge space 20 and atmospheric pressure in the device-outside space 80.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical device and a charged particle beam device. [Background technology]

[0002] In the manufacturing process of semiconductor devices, foreign matter or pattern defects may occur on a wafer, which is a semiconductor substrate. Pattern defects include short circuits and open circuit defects. In the following, such foreign matter or pattern defects will be simply referred to as "defects." These defects occur during the manufacturing process for various reasons. Therefore, in mass-producing semiconductor devices, it is important to detect defects that occur during the manufacturing process early, identify their source, and prevent a decrease in yield.

[0003] One method for identifying the source of a defect is to use an optical defect inspection device to identify the position coordinates of the defect, and then use the coordinate information to observe the defect in detail using a charged particle beam device such as a scanning electron microscope (SEM), thereby estimating the source of the defect.

[0004] In the optical defect inspection device, a method is used in which a laser beam is irradiated onto a wafer, and the position coordinates of the defect are identified by detecting the scattered light when the laser beam hits the defect. In addition, there is a discrepancy between the coordinate system of the optical defect inspection device and the coordinate system of the SEM. In order to correct the discrepancy, a method is used in which the optical microscope mounted on the SEM is used to re-inspect the defect or correct the coordinate information of the defect, thereby improving the success rate of defect capture by the SEM. For example, Patent Document 1 discloses a defect observation device equipped with an optical microscope and an electron microscope.

[0005] As semiconductor devices become finer, it is becoming necessary to detect and identify the source of even finer defects. The defect detection sensitivity of optical defect inspection equipment and optical microscopes mounted on SEMs improves as the wavelength of the laser light used becomes shorter, so the wavelength of the laser light used to detect defects is becoming shorter.

[0006] On the other hand, deep-ultraviolet light with a wavelength of less than 300 nm reacts with contaminant sources such as oxygen and organic gases on the optical path, causing contamination on the surface of optical elements. The accumulation of contamination reduces the performance of optical elements by reducing their transmittance and reflectance, etc. This is an issue when using deep-ultraviolet light.

[0007] Patent Document 2 discloses a technology that uses a photocatalyst to decompose contaminants that cloud optical elements in an exposure apparatus. Patent Document 3 discloses a system that reduces contamination by gas purging. In a system in which the optical axis passes through a gas purge area and a vacuum area, a technology is disclosed that prevents contaminants from entering the vacuum area by injecting purge gas in the opposite direction to the vacuum area.

[0008] A common anti-contamination method is to inject clean inert gas through a filter into the inside of a vessel containing the laser optical path to expel contaminants and oxygen (inert gas purging method). The inert gas is, for example, a rare gas such as nitrogen or argon. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2007-235023 A [Patent Document 2] JP 2005-72076 A [Patent Document 3] US Patent Application Publication No. 2022 / 0382046 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to expel contaminants and oxygen from the optical path and prevent them from re-entering, it is necessary to fill the container with clean inert gas. On the other hand, if the inert gas leaks out of the container, it may reduce the oxygen concentration in the space surrounding the container.

[0011] In the case of an SEM apparatus equipped with an optical microscope, the microscope is installed inside the cover of the SEM apparatus, and a decrease in the oxygen concentration inside the SEM apparatus may be an obstacle when an operator performs maintenance work.

[0012] It is conceivable to avoid such problems by making the container a sealed container. To do so, the container needs to be manufactured by a method such as integral molding or machining, and there needs to be no places for gas to enter or exit. However, such a method leads to an increase in manufacturing costs.

[0013] In addition, when a deep ultraviolet light irradiation device such as a laser head or an optical element having an electrically-driven part is contained in a container that contains the optical path to be purged, a structure is required to pull out the power supply and control cables to the outside of the optical path container, which makes it difficult to create a completely sealed space in the first place.

[0014] Similarly, even when a part of the deep ultraviolet light irradiation device including the emission port is enclosed inside the container, the container is no longer integrally molded, and therefore the airtightness is reduced.

[0015] The main objective of the present application is to provide a technology that can prevent the inflow of gas containing contaminants into a container and the outflow of inert gas to the outside of a container, even if the container is not completely sealed.

[0016] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0017] In one embodiment, the optical device includes a light irradiation device capable of irradiating light, a plurality of container parts, a first gas supply port, a first gas suction port, and a first optical element. The plurality of container parts respectively separate a first space to which an inert gas is supplied, a second space to which the existing gas is sucked, and a third space that is a space outside the plurality of container parts, the first gas supply port reaches the first space, the first gas suction port reaches the second space, the first space is used as an optical path for the light, and the first optical element is provided in the first space, and the first gas supply port supplies the inert gas to the first space and sucks the gas existing in the second space from the first gas suction port, thereby controlling the air pressure in the second space to be lower than the air pressure in the first space and the air pressure in the third space. Effect of the Invention

[0018] According to the optical device in one embodiment, it is possible to prevent the inflow of gas containing contaminants into the inside of the container and the outflow of inert gas to the outside of the container. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram showing an optical device according to a first embodiment. [Diagram 2] 10 is a schematic diagram showing a part of an optical device in a first modified example. FIG. [Diagram 3] 11 is a schematic diagram showing a part of an optical device in a second modified example. FIG. [Figure 4] FIG. 13 is a schematic diagram showing a part of an optical device in a third modified example. [Diagram 5] FIG. 11 is a schematic diagram showing an optical device according to a second embodiment. [Figure 6] FIG. 11 is a schematic diagram showing an optical device according to a third embodiment. [Figure 7] FIG. 11 is a perspective view showing a plurality of container parts in the third embodiment. [Figure 8] FIG. 13 is a perspective view showing a container part in Modification 4. [Figure 9]FIG. 13 is a cross-sectional view showing a container part in a fourth modified example. [Figure 10] FIG. 13 is a perspective view showing a container part in Modification 5. [Figure 11] FIG. 13 is a cross-sectional view showing a container part in Modification 5. [Figure 12] FIG. 13 is a schematic diagram showing an optical device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, the embodiments will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same reference numerals are used for the members having the same functions, and the repeated explanations are omitted. In the following embodiments, the explanations of the same or similar parts will not be repeated as a rule unless it is particularly necessary.

[0021] In the present application, the X, Y, and Z directions intersect each other and are perpendicular to each other. In the present application, the Z direction will be described as the up-down direction of a structure.

[0022] (Embodiment 1) An optical device 100 according to the first embodiment will be described below with reference to FIG.

[0023] As shown in FIG. 1, the optical device 100 mainly includes a light irradiation device 1, an optical element 4a, an optical element 4b, a photodetector 6, a stage 11, a sample container part 12, a plurality of container parts 13, 21, 31, a gas supply port 22, a gas supply adjustment device 23, an exhaust port 24, a gas suction port 32 and a gas suction adjustment device 33.

[0024] The light irradiation device 1 is provided on a flat container part 13, has a light source 1a, and is capable of irradiating light 3 from the light source 1a. The light 3 is, for example, light having a wavelength of 300 nm or less, i.e., deep ultraviolet light. The sample container part 12 is joined to the container part 13 using an O-ring or the like. The space surrounded by the sample container part 12 and the container part 13 is the sample space 10, which is a sealed space. A sealing window 14 that is capable of transmitting the light 3 is attached to a part of the container part 13.

[0025] The container parts 13, 21, and 31 separate the purge space 20 to which the inert gas is supplied, the gas suction space 30 to which the existing gas is suctioned, and the external space 80. The external space 80 is a space in which the outflow of the inert gas is undesirable, and is the space outside the sample container part 12 and the container parts 13, 21, and 31, and is the space around the optical device 100.

[0026] One or more optical elements 4a are provided in the sample space 10. One or more optical elements 4b are provided in the purge space 20. These optical elements 4a and 4b include, for example, an element for switching the optical path of the light 3, such as a mirror, and an element for manipulating the intensity, polarization, beam diameter, etc. of the light 3.

[0027] The stage 11 is provided in the sample space 10 and is capable of mounting a sample 5 thereon. The sample 5 is, for example, a wafer including a semiconductor substrate, a semiconductor element such as a transistor formed on the semiconductor substrate, and a plurality of wirings formed on the semiconductor element.

[0028] The photodetector 6 is provided in the sample space 10 and is capable of detecting scattered light or fluorescence emitted from the sample 5. Based on the detection result by the photodetector 6, the position coordinates of the defect in the sample 5 can be identified.

[0029] The purge space 20 is used as an optical path for the light 3. The light 3 irradiated from the light irradiation device 1 passes through a plurality of optical elements 4b, 4a, enters the sample space 10 from the purge space 20, and reaches the sample 5. When entering the sample space 10 from the purge space 20, the light 3 passes through a sealing window 14. Thereafter, the position coordinates of the defect are identified using a photodetector 6.

[0030] The cover-like container part 21 can be bent, for example, and is made of a thin metal plate, and is joined to the container part 13. The purge space 20 is a space surrounded by the container part 13 and the container part 21. Also, at least a part of the light irradiation device 1 is covered by the container part 21 so that the light source 1a of the light irradiation device 1 is located in the purge space 20. Therefore, the purge space 20 in the first embodiment is a space surrounded by the light irradiation device 1, the container part 13, and the container part 21.

[0031] The gas supply port 22 is provided in the container part 21 so as to reach the purge space 20. The gas supply regulator 23 is attached to the gas supply port 22. The gas supply regulator 23 is used to regulate the supply amount of the inert gas, and is, for example, a regulator. Although not shown here, the gas supply port 22 is connected to a gas supply device such as a pump provided outside the optical device 100. The inert gas is supplied to the purge space 20 by the gas supply device. The inert gas is, for example, a rare gas such as nitrogen or argon.

[0032] Here, the purpose of supplying the inert gas to the purge space 20 is not to seal the inert gas, but to continue the inflow and exhaust of the gas so as to prevent the accumulation of contaminants in the purge space 20. Therefore, the inert gas is continuously (constantly) supplied from the gas supply port 22 to the purge space 20.

[0033] In the purge space 20, the space between the sealing window 14 and the container part 13 is sealed, but gas may flow in and out between, for example, the container part 21 and the container part 13, and between the container part 21 and the light irradiation device 1. For this reason, in the first embodiment, a gas suction space 30 is provided between the purge space 20 and the space outside the device 80 by the container part 31.

[0034] The cover-like container part 31 is made of a thin metal plate that can be bent, for example, and is joined to the container part 13 so as to cover the container part 21. The gas suction space 30 is a space surrounded by the container part 13, the container part 21, and the container part 31. The gas suction port 32 is provided in the container part 31 so as to reach the gas suction space 30. A gas suction adjustment device 33 for adjusting the suction force is attached to the gas suction port 32. Although not shown here, the gas suction port 32 is connected to a gas suction device such as a pump provided outside the optical device 100. The gas suction device sucks the gas present in the gas suction space 30 from the gas suction port 32. The sucked gas is collected in a safe place by another means.

[0035] In the gas suction space 30, gas may flow in and out between the container part 31 and the container part 13. The container part 31 is provided with a cable hole 34 for pulling out the cable 2 of the light irradiation device 1. Gas may flow in and out through this hole 34 as well.

[0036] Therefore, when detecting defects in the sample 5, an inert gas is supplied from the gas supply port 22 to the purge space 20, and the gas present in the gas suction space 30 is sucked from the gas suction port 32. This makes it possible to control the air pressure in the gas suction space 30 to be lower than the air pressure in the purge space 20 and the air pressure in the space 80 outside the apparatus.

[0037] As a result, even if the inert gas flows out from the purge space 20 to the gas suction space 30, the inert gas is sucked into the gas suction port 32. It is also possible to prevent the gas from flowing out from the external space 80 to the purge space 20 and the gas from flowing out from the gas suction space 30 to the external space 80. That is, according to the first embodiment, even if the container is not completely sealed, it is possible to prevent other gases from flowing into the purge space 20 and to prevent the inert gas from flowing out to the outside of the optical device 100.

[0038] Furthermore, when the sample 5 is placed on the stage 11 and defect detection of the sample 5 is performed, the light 3 is irradiated from the light irradiation device 1 in a state where the air pressure in the gas suction space 30 is controlled to be lower than the air pressure in the purge space 20 and the air pressure in the space outside the device 80. Since the purge space 20, which is the optical path of the light 3, is filled with an inert gas, the accumulation of contamination is suppressed even when deep ultraviolet light is used when the sample 5 is placed on the stage 11 and defect detection of the sample 5 is performed. Therefore, the performance of the optical element 4b and the light source 1a can be suppressed from deteriorating.

[0039] The container part 21 is also provided with an exhaust port 24. The inert gas filling the purge space 20 is naturally exhausted from the exhaust port 24 to the outside of the optical device 100. The exhausted inert gas is collected to a safe place by a separate means. However, in a design in which all of the inert gas supplied to the purge space 20 is exhausted from the gas suction port 32 via the gas suction space 30, the exhaust port 24 does not need to be provided.

[0040] The sample space 10 is kept in a vacuum. In particular, when the optical device 100 is part of a configuration included in a charged particle beam device such as an SEM device, the sample space 10 is also used in the observation process of an SEM image, so it is desirable that the sample space 10 be in a vacuum. When the sample space 10 is in a vacuum, contaminants and oxygen are eliminated, so there is no concern about contamination in the sample space 10. The light 3 can enter the sample space 10 from the purge space 20 by passing through the sealing window 14. The sample space 10 can also be purged with an inert gas. In that case, a mechanism that plays the same role as the gas supply port 22 and the exhaust port 24 may be provided in the sample container 12.

[0041] The charged particle beam device is equipped with an electron beam column capable of irradiating an electron beam into a sample space 10, and a stage 11 on which a sample 5 is placed can move between a position where the light 3 reaches and a position where the electron beam is irradiated. This allows the SEM image observation process to be performed immediately after defect detection by the optical device 100 is completed.

[0042] (Variation 1) Modification 1 of the first embodiment will be described below with reference to Fig. 2. Note that, in Modifications 1, 2, and 3, cases will be described in which the position of the light irradiation device 1 is different from that of the first embodiment, but for simplification, the description will be given using drawings in which the configuration below the container part 13, such as the sample space 10, is omitted.

[0043] 2, in the first modification, the entire light irradiation device 1 is covered by a container part 21 so that the light source 1a is located in the purge space 20. Therefore, the container part 21 is provided with a hole 25 for the cable to pull out the cable 2. For example, if the space between the cable 2 and the hole 25 can be sealed by an effective means, the degree of sealing of the purge space 20 can be improved.

[0044] (Variation 2) The second modification of the first embodiment will be described below with reference to FIG.

[0045] 3, in the second modification, the entire light irradiation device 1 is provided outside the container part 31 so that the light source 1a is located in the space outside the device 80. For this reason, a sealing window 26 capable of transmitting the light 3 is attached to a part of the container part 21. In addition, a sealing window 35 capable of transmitting the light 3 is attached to a part of the container part 31. The light 3 can enter the gas suction space 30 from the space outside the device 80 by transmitting through the sealing window 35, and can enter the purge space 20 from the gas suction space 30 by transmitting through the sealing window 26.

[0046] In the second modification, since the area from the light source 1a to the outside of the sealing window 26 is not subject to purging, there is a concern that contamination may adhere to the light irradiation device 1 and the sealing windows 26 and 35. However, since the light irradiation device 1 is not used as a component of the purge space 20, the degree of sealing of the purge space 20 can be increased, making it easier to suppress the risk of contamination adhering to the optical element 4b. If the cost of cleaning or replacing the optical element 4b is higher than the cost of cleaning or replacing each of the light source 1a, the sealing window 26, and the sealing window 35, the increase in the cost of cleaning or replacing can be suppressed. Furthermore, when replacing the light irradiation device 1 itself, the second modification allows the replacement work to be performed simply.

[0047] (Variation 3) The third modification of the first embodiment will be described below with reference to FIG.

[0048] 4, in the third modification, at least a part of the light irradiation device 1 is covered by a container part 31 so that the light source 1a is located in the gas suction space 30. For this reason, a sealing window 26 that is transmissible to the light 3 is attached to a part of the container part 21. The light 3 can enter the purge space 20 from the gas suction space 30 by transmitting through the sealing window 26.

[0049] In the third modification, as in the second modification, the area from the light source 1a to the outside of the sealing window 26 is not subject to purging, so there is a concern that contamination may adhere to the light irradiation device 1, but this effect is less in the third modification than in the second modification. In addition, since the light irradiation device 1 is not used as a component of the purge space 20, the degree of sealing of the purge space 20 can be increased, so that it becomes easier to suppress the risk of contamination adhering to the optical element 4.

[0050] (Embodiment 2) An optical device 100 in the second embodiment will be described below with reference to Fig. 5. In the following description, differences from the first embodiment will be mainly described, and descriptions of points that overlap with the first embodiment will be omitted.

[0051] In the first embodiment, the sample space 10 and the purge space 20 are separate spaces. In the second embodiment, an opening 13a is provided in a part of the container part 13, and the sample space 10 and the purge space 20 are the same space. Therefore, when detecting defects in the sample 5, the sample space 10 and the purge space 20 are filled with an inert gas. Since the optical path of the light 3 is filled with an inert gas, accumulation of contamination is suppressed even when deep ultraviolet light is used.

[0052] The optical device 100 of the second embodiment is applied to cases where it is not essential that the sample space 10 be a vacuum. The task of creating a vacuum in the sample space 10 is eliminated, and the device configuration is simplified.

[0053] The techniques disclosed in Modifications 1, 2, and 3 can also be applied to the second embodiment.

[0054] (Embodiment 3) An optical device 100 according to the third embodiment will be described below with reference to Figures 6 and 7. In the following description, differences from the first embodiment will be mainly described, and descriptions of points that overlap with the first embodiment will be omitted.

[0055] In the first embodiment, two layers of container parts, that is, container part 13 and container part 21, are used to form purge space 20 and gas suction space 30. In the third embodiment, a single layer of container part and a groove formed therein are used to form the purge space and the gas suction space.

[0056] 6 and 7, the optical device 100 of the third embodiment includes a plurality of flat container parts 41, 42, 43, 44, 45, and 46. The container part 45 and the container part 46 face each other, and the plurality of container parts 41, 42, 43, and 44 are joined to each other by means of screwing or the like. In addition, some of the plurality of container parts 41, 42, 43, and 44 are joined to each other by means of screwing or the like. In other words, the container parts 41, 42, 43, 44, 45, and 46 are joined to each other with container parts other than the container parts they face.

[0057] In this embodiment, the shape of container part 45 constituting the upper wall and the shape of container part 46 constituting the lower wall are rectangular, but may be other polygonal shapes. Also, the number of container parts 41, 42, 43, 44 constituting the side walls is not limited to four, and may be five or more.

[0058] In the third embodiment, the purge space 40, the gas suction space, and the outside space 80 are also separated from each other by the container parts 41, 42, 43, 44, 45, and 46. The space surrounded by the container parts 41, 42, 43, 44, 45, and 46 constitutes the purge space 40 to which the inert gas is supplied. One or more optical elements 4b are also provided in the purge space 40.

[0059] The light irradiation device 1 is provided on a container part 45. One or more optical elements 4c are provided in the external space 80. The optical elements 4c are the same as the optical elements 4a and 4b. A container part 46 facing the container part 45 is joined to the sample container part 12 using an O-ring or the like. A sealing window 47 is attached to a part of the container part 45, and a sealing window 48 is attached to a part of the container part 46.

[0060] The purge space 40 is also used as an optical path for the light 3. The light 3 irradiated from the light irradiation device 1 passes through a plurality of optical elements 4c, 4b, and 4a, enters the purge space 40 from the space outside the device 80, enters the sample space 10 from the purge space 40, and reaches the sample 5. When entering the purge space 40 from the space outside the device 80, the light 3 passes through a sealing window 47. When entering the sample space 10 from the purge space 40, the light 3 passes through a sealing window 48. Thereafter, the position coordinates of the defect are identified using the photodetector 6.

[0061] Grooves 61, 62, 63, 64 are formed along the joint surfaces of the container part 45 and the container parts 41, 42, 43, 44, the joint surfaces of the container part 46 and the container parts 41, 42, 43, 44, and the joint surfaces of the container parts 41, 42, 43, 44. That is, the grooves 61, 62, 63, 64 are formed in the container parts 41, 42, 43, 44, respectively. The grooves 63, 64 are also formed in the up-down direction (Z direction). Therefore, when the container parts 41, 42, 43, 44, 45, 46 are joined together as one container, the grooves 61, 62, 63, 64 communicate with each other as one groove. The grooves 61, 62, 63, 64 function as gas suction spaces corresponding to the gas suction space 30 in the first embodiment.

[0062] The container parts 41, 42, 43, 44, 45, 46 are made of thick metal plates, for example of aluminum or copper. The grooves 61, 62, 63, 64 are formed in the container parts 41, 42, 43, 44 by cutting.

[0063] A gas supply port 49 is provided in the container part 42, leading to the purge space 40. A gas supply regulator 50 is attached to the gas supply port 49. A gas suction port 51 is provided in the container part 45, leading to the groove 61. A gas suction regulator 52 is attached to the gas suction port 51. An exhaust port 53 is provided in the container part 41.

[0064] The gas supply regulator 50 and the gas suction regulator 52 have the same functions as the gas supply regulator 23 and the gas suction regulator 33 of the first embodiment, respectively. Although not shown here, the gas supply port 49 is connected to a gas supply device such as a pump provided outside the optical device 100. The gas supply device supplies an inert gas to the purge space 40. The gas suction port 51 is connected to a gas suction device such as a pump provided outside the optical device 100. The gas suction device sucks gas present in the gas suction space from the gas suction port.

[0065] In the third embodiment, when the container parts 41, 42, 43, 44, 45, and 46 are joined together to form a single container, gas may flow in and out from the joining surfaces. However, a gas suction space consisting of grooves 61, 62, 63, and 64 is provided between the purge space 40 and the outside space 80.

[0066] Therefore, when detecting defects in the sample 5, an inert gas is supplied from the gas supply port 49 to the purge space 40, and the gas present in the gas suction space (grooves 61, 62, 63, 64) is sucked from the gas suction port 51. This makes it possible to control the air pressure in the gas suction space to be lower than the air pressure in the purge space 40 and the air pressure in the space 80 outside the apparatus.

[0067] When a sample 5 is placed on the stage 11 and defects in the sample 5 are detected, light 3 is irradiated from the light irradiation device 1 while controlling the air pressure in the gas suction space 30 to be lower than the air pressure in the purge space 40 and the air pressure in the space outside the device 80.

[0068] In the third embodiment, as in the first embodiment, even if the container is not completely sealed, it is possible to prevent other gases from flowing into the purge space 40 and prevent the inert gas from flowing out of the optical device 100. Since the purge space 40, which is the optical path of the light 3, is filled with the inert gas, the accumulation of contamination is suppressed even when deep ultraviolet light is used. Therefore, it is possible to suppress the performance of the optical element 4b from being deteriorated.

[0069] Furthermore, in the structure using the grooves 61, 62, 63, and 64 of the third embodiment, since it is not necessary to add new parts to provide the gas suction space, there is an advantage that the number of parts can be reduced compared to the first embodiment.

[0070] In this embodiment, the grooves 61, 62, 63, and 64 are formed in the container parts 41, 42, 43, and 44, but the grooves may be formed along the joint surfaces of the container parts. For example, the container parts 45 and 46 may also have grooves.

[0071] Moreover, the gas supply port 49, the gas suction port 51, and the exhaust port 53 are not limited to being provided in the container parts 42, 45, and 41, respectively, and may be provided in other container parts. That is, the gas supply port 49, the gas suction port 51, and the exhaust port 53 are provided in any of the container parts 41, 42, 43, 44, 45, and 46. Moreover, a plurality of gas suction ports 51 may be provided in consideration of the balance of air pressure.

[0072] (Variation 4) The fourth modification of the third embodiment will be described below with reference to Figures 8 and 9. Figure 9 is a cross-sectional view taken along the line AA in Figure 8.

[0073] 8 and 9, in the fourth modification, a through hole 65 that connects the purge space 40 to the apparatus-external space 80 is formed in the container part 43. In other words, the container part 43 has an inner wall surface on the purge space 40 side and an outer wall surface on the apparatus-external space 80 side, and the through hole 65 is formed to penetrate the outer wall surface and the inner wall surface of the container part 43.

[0074] For example, adjustment or maintenance of the multiple optical elements 4b may be required, and access to the inside of the purged space 40 may be required. In that case, if a structure is provided that allows access to the inside of the purged space 40 without dismantling the container parts 41, 42, 43, 44, 45, and 46, the above work can be easily performed. The through-hole 65 is provided to fulfill this role.

[0075] A sealing part 70 is joined to the container part 43 by means of screws or the like so as to cover the through-hole 65. However, the joint surface between the container part 43 and the sealing part 70 is not sealed, so gas may flow in and out. One possible method for sealing the through-hole 65 is to fit an O-ring. However, when it is expected that it would be difficult to use an O-ring, such as when there is a concern about deterioration of the O-ring or when the O-ring itself could be a source of contamination, Modification 4 is useful.

[0076] A recess 66 is formed in the container part 43 around the through hole 65. The recess 66 is formed to reach a predetermined depth from the outer wall surface in the direction from the outer wall surface to the inner wall surface of the container part 43. A hole 67 is formed in the bottom of the groove 63 of the container part 43 so as to connect the groove 63 and the recess 66. The sealing part 70 is provided so as to cover the recess 66 as well.

[0077] Since the groove 63 and the recess 66 communicate with each other through the hole 67, the inside of the recess 66 also becomes part of the gas suction space. Therefore, even if the inert gas flows out to the periphery of the through hole 65, the inert gas is sucked in through the gas suction port 51.

[0078] In this way, according to the fourth modification, it is possible to easily access the inside of the purge space 40 and to prevent the outflow of the inert gas.

[0079] The container part in which the through hole 65, the recess 66 and the hole 67 are formed is not limited to the container part 43, but may be the container parts 41, 42, and 44.

[0080] (Variation 5) The fifth modification of the third embodiment will be described below with reference to Figures 10 and 11. Figure 11 is a cross-sectional view taken along the line BB in Figure 10.

[0081] Similar to the fourth modification, the fifth modification also has a structure designed to facilitate access to the inside of the purge space 40.

[0082] A recess 69 is formed in the container part 43. The recess 69 is formed to reach a predetermined depth from the outer wall surface in a direction from the outer wall surface to the inner wall surface of the container part 43. A through hole 68 is formed at the bottom of the recess 69, which opens between the purge space 40 and the space outside the apparatus 80. The through hole 68 is formed to penetrate the outer wall surface of the container part 43 and the bottom of the recess 69.

[0083] A hole 67 is formed in the bottom of the groove 63 of the container part 43 so as to connect the groove 63 to a recess 69. A sealing part 70 is joined to the bottom of the recess 69 by means of screwing or the like so as to cover the through hole 68. A sealing part 71 is joined to the container part 43 by means of screwing or the like so as to cover the recess 69.

[0084] Since the groove 63 and the recess 69 communicate with each other through the hole 67, the inside of the recess 69 also becomes part of the gas suction space. That is, the space between the sealing parts 70 and 71 becomes part of the gas suction space. Therefore, even if the inert gas flows out around the through hole 68, the inert gas is sucked in through the gas suction port 51.

[0085] In this manner, also in the fifth modification, access to the inside of the purge space 40 can be made easy, and outflow of the inert gas can be prevented.

[0086] The container part in which the through hole 68, the recess 69 and the hole 67 are formed is not limited to the container part 43, but may be the container parts 41, 42, and 44.

[0087] (Embodiment 4) An optical device 100 in the fourth embodiment will be described below with reference to Fig. 12. In the following description, differences from the third embodiment will be mainly described, and descriptions of points that overlap with the third embodiment will be omitted.

[0088] 12, in the fourth embodiment, container parts 41, 42, 43, 44, 45, 46, etc. similar to those in the third embodiment are applied, and also container parts 21, 31, etc. in the first embodiment are applied. The light irradiation device 1 is provided on the container part 45. The container parts 21, 31 are each joined to the container part 45. The optical element 4c, which is provided in the space outside the device 80 in the third embodiment, is provided in the purge space 20.

[0089] When detecting defects in the sample 5, an inert gas is supplied from the gas supply port 22 to the purge space 20, and gas present in the gas suction space 30 is sucked from the gas suction port 32. At the same time, an inert gas is supplied from the gas supply port 49 to the purge space 40, and gas present in the gas suction space (grooves 61, 62, 63, 64) is sucked from the gas suction port 51. The air pressure in the gas suction space 30 and the gas suction space (grooves 61, 62, 63, 64) can be controlled to be lower than the air pressure in the purge space 20, the air pressure in the purge space 40, and the air pressure in the space outside the apparatus 80.

[0090] When the sample 5 is placed on the stage 11 and defects in the sample 5 are detected, the air pressure in the gas suction space 30 and the gas suction space (grooves 61, 62, 63, 64) is controlled to be lower than the air pressure in the purge space 20, the air pressure in the purge space 40, and the air pressure in the space outside the apparatus 80, and light 3 is irradiated from the light irradiation device 1.

[0091] Light 3 irradiated from the light irradiation device 1 passes through a plurality of optical elements 4c, 4b, and 4a, enters the purge space 20 into the purge space 40, enters the purge space 40 into the sample space 10, and reaches the sample 5. When entering the purge space 40 from the purge space 20, the light 3 passes through a sealing window 47. When entering the sample space 10 from the purge space 40, the light 3 passes through a sealing window 48. Thereafter, the position coordinates of the defect are identified using the photodetector 6.

[0092] The container parts 41, 42, 43, 44, 45, and 46 are made of relatively thick metal plates, and are therefore suitable for supporting the weight of the light irradiation device 1. On the other hand, the container parts 21 and 31 are made of lightweight, relatively thin metal plates. For example, when it is necessary to pull out the cable 2 of the light irradiation device 1, processing is required to form holes 25 and 34 for the cable 2 in the container parts 21 and 31, but if the container parts 21 and 31 are made of thin metal plates, such processing is easy.

[0093] In addition, in the third embodiment, some of the optical elements 4c are provided in the extra-apparatus space 80, but in the fourth embodiment, such optical elements 4c can be disposed in the purge space 20. This can suppress the risk of contamination adhering to the optical elements 4b, 4c, thereby maintaining the performance of the optical elements 4b, 4c and suppressing an increase in the cost of cleaning or replacing the optical elements 4b, 4c.

[0094] Regarding the position of the light irradiation device 1, any of Modifications 1, 2, and 3 may be applied. In addition, the technology described in Modification 4 or Modification 5 may be applied to the container parts 41, 42, 43, and 44.

[0095] Although the present invention has been specifically described above based on the above embodiment, the present invention is not limited to the above embodiment and can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0096] 100 Optical equipment 1 Light irradiation device 1a light source 2 Cable 3 light 4a, 4b, 4c Optical elements 5. Sample 6. Photodetector 10 Sample Space 11 Stage 12 Sample container parts 13 Container parts 13a opening 14 Sealing window 20 Purge Space 21 Container parts 22 Gas supply port 23 Gas supply regulators 24 Outlet 25 Cable hole 26 Sealing window 30 Gas suction space 31 Container parts 32 Gas suction port 33 Gas suction regulator 34 Cable hole 35 Sealing window 40 Purge Space 41, 42, 43, 44, 45, 46 Container parts 47, 48 Sealing window 49 Gas supply port 50 Gas supply regulator 51 Gas suction port 52 Gas suction regulator 53 Outlet 61, 62, 63, 64 Groove (gas suction space) 65 Through hole 66 Recess 67 holes 68 Through Hole 69 Recess 70, 71 Sealing parts 80 Space outside the device

Claims

1. A light irradiation device capable of irradiating light; A plurality of container parts; A first gas supply port; A first gas suction port; A first optical element; Equipped with The plurality of container parts respectively separate a first space to which an inert gas is supplied, a second space to which an existing gas is sucked, and a third space which is a space outside the plurality of container parts; the first gas supply port reaches the first space, the first gas suction port reaches the second space, the first space is used as an optical path for the light, The first optical element is provided in the first space, An optical device capable of controlling the air pressure in the second space to be lower than the air pressure in the first space and the air pressure in the third space by supplying an inert gas to the first space from the first gas supply port and sucking in the gas present in the second space from the first gas suction port.

2. 2. The optical device according to claim 1, The optical device, wherein the light is deep ultraviolet light.

3. 2. The optical device according to claim 1, The plurality of container parts include a first container part having a flat plate shape, a second container part having a cover shape, and a third container part having a cover shape, the light irradiation device is provided on the first container part, the second container part is joined to the first container part; the first space is a space surrounded by the first container part and the second container part, the third container parts are joined to the first container part so as to cover the second container part; the second space is a space surrounded by the first container part, the second container part, and the third container part, the first gas supply port is provided in the second container part; The first gas inlet is provided in the third container part.

4. 4. The optical device according to claim 3, a sample container part joined to the first container part among the plurality of container parts; a sample space surrounded by the first container part and the sample container part; a stage provided in the sample space and capable of supporting a sample; a photodetector provided in the sample space and capable of detecting scattered light or fluorescence emitted from the sample; A second optical element provided in the sample space; and Further comprising: An optical device in which, when the sample is placed on the stage and defects of the sample are detected, the air pressure in the second space is controlled to be lower than the air pressure in the first space and the air pressure in the third space, and the light irradiated from the light irradiation device passes through the first optical element and the second optical element, enters the sample space from the first space, and reaches the sample.

5. 5. The optical device according to claim 4, an opening is provided in a portion of the first container part so that the first space and the sample space are the same space; The first space and the sample space are filled with the inert gas.

6. 5. The optical device according to claim 4, a sealing window attached to a portion of the first container part and capable of transmitting the light; The light can enter the sample space from the first space by transmitting through the sealing window, The sample space is maintained at a vacuum.

7. A charged particle beam device including the optical device according to claim 6, an electron beam column that is provided in the sample space and is capable of irradiating an electron beam; A charged particle beam device, wherein the stage can move within the sample space between a position where the light reaches and a position where the electron beam is irradiated.

8. 4. The optical device according to claim 3, An optical device, wherein at least a portion of the light irradiation device is covered by the second container part such that a light source of the light irradiation device is located in the first space.

9. 4. The optical device according to claim 3, a sealing window attached to a portion of the second container part and capable of transmitting the light; At least a portion of the light irradiation device is covered by the third container part such that a light source of the light irradiation device is located in the second space; The optical device, wherein the light can enter the first space from the second space by passing through the sealing window.

10. 4. The optical device according to claim 3, a first sealing window attached to a portion of the second container part and capable of transmitting the light; a second sealing window attached to a portion of the third container part and capable of transmitting the light; Further comprising: the light irradiation device is provided outside the third container part such that a light source of the light irradiation device is located in the third space; An optical device, wherein the light can enter the second space from the third space by passing through the second sealing window, and can enter the first space from the second space by passing through the first sealing window.

11. 4. The optical device according to claim 3, The plurality of container parts include a fourth container part having a flat plate shape facing the first container part; a plurality of flat plate-shaped fifth container parts respectively joined to the first container part and the fourth container part; Including, At least a portion of the plurality of fifth container parts are joined to one another; a space surrounded by the first container part, the fourth container part, and the plurality of fifth container parts constitutes a fourth space; a groove that forms a fifth space is formed along a joint surface between the first container part and the plurality of fifth container parts, along a joint surface between the fourth container part and the plurality of fifth container parts, and along a joint surface between the plurality of fifth container parts; a second gas supply port is provided in any one of the first container part, the fourth container part, or the plurality of fifth container parts so as to reach the fourth space; a second gas suction port is provided in any one of the first container part, the fourth container part, or the plurality of fifth container parts so as to reach the groove; the fourth space is used as an optical path for the light, a third optical element is provided in the fourth space, An optical device capable of controlling the air pressure in the fifth space to be lower than the air pressure in the fourth space and the air pressure in the third space by supplying an inert gas from the second gas supply port to the fourth space and sucking in the gas present in the fifth space through the second gas suction port.

12. 12. The optical device according to claim 11, A sixth container part among the plurality of fifth container parts has a through hole that connects the fourth space and the third space, A recess is formed in the sixth container part around the through hole, A hole is formed in a bottom portion of the groove of the sixth container part so as to connect the groove and the recess, An optical device, wherein a sealing part is joined to the sixth container part so as to cover the through hole and the recess.

13. 12. The optical device according to claim 11, A sixth container part of the plurality of fifth container parts has a recess formed therein, a through hole that connects the fourth space and the third space to each other is formed in a bottom of the recess; A hole is formed in a bottom portion of the groove of the sixth container part so as to connect the groove and the recess, a first sealing component is joined to a bottom of the recess so as to cover the through hole; An optical device, wherein a second sealing part is joined to the sixth container part so as to cover the recess.

14. 12. The optical device according to claim 11, a sample container part joined to the fourth container part; a sample space surrounded by the fourth container part and the sample container part; a stage provided in the sample space and capable of supporting a sample; a photodetector provided in the sample space and capable of detecting scattered light or fluorescence emitted from the sample; A second optical element provided in the sample space; and Further comprising: an optical device in which, when the sample is placed on the stage and defects of the sample are detected, the air pressure in the second space and the air pressure in the fifth space are controlled to be lower than the air pressure in the first space, the air pressure in the fourth space, and the air pressure in the third space, and the light irradiated from the light irradiation device passes through the first optical element, the third optical element, and the second optical element, enters from the first space to the fourth space, enters from the fourth space into the sample space, and reaches the sample.

15. A charged particle beam device including the optical device according to claim 14, a first sealing window attached to a portion of the first container part and capable of transmitting the light; a second sealing window attached to a portion of the fourth container part and capable of transmitting the light; an electron beam column provided in the sample space and capable of irradiating an electron beam; Further comprising: while the sample space is maintained in vacuum, the light can enter the fourth space from the first space by transmitting through the first sealing window, and can enter the sample space from the fourth space by transmitting through the second sealing window, A charged particle beam device, wherein the stage can move within the sample space between a position where the light reaches and a position where the electron beam is irradiated.

16. 2. The optical device according to claim 1, The plurality of container parts include A first container part having a flat plate shape; a second container part having a flat plate shape facing the first container part; a plurality of flat third container parts joined to the first container part and the second container part, respectively; Including, At least some of the plurality of third container parts are joined together; the light irradiation device is provided on the first container part, the first space is a space surrounded by the first container part, the second container part, and the plurality of third container parts, a groove that constitutes the second space is formed along a joint surface between the first container part and the plurality of third container parts, along a joint surface between the second container part and the plurality of third container parts, and along a joint surface between the plurality of third container parts, a first gas supply port is provided in any one of the first container part, the second container part, or the plurality of third container parts so as to reach the first space; An optical device, wherein a first gas suction port is provided in any one of the first container part, the second container part, or the plurality of third container parts so as to reach the groove.

17. 17. The optical device according to claim 16, A through hole that connects the first space and the third space is formed in a fourth container part among the plurality of third container parts, A recess is formed in the fourth container part around the through hole, A hole is formed in a bottom of the groove of the fourth container part so as to connect the groove and the recess, An optical device, wherein a sealing part is joined to the fourth container part so as to cover the through hole and the recess.

18. 17. The optical device according to claim 16, A recess is formed in a fourth container part among the plurality of third container parts, a through hole that connects the first space and the third space to each other is formed in a bottom of the recess; A hole is formed in a bottom portion of the groove of the fourth container part so as to connect the groove and the recess, a first sealing component is joined to a bottom of the recess so as to cover the through hole; An optical device, wherein a second sealing part is joined to the fourth container part so as to cover the recess.

19. 17. The optical device according to claim 16, a sample container part joined to the second container part; a sample space surrounded by the second container part and the sample container part; a stage provided in the sample space and capable of supporting a sample; a photodetector provided in the sample space and capable of detecting scattered light or fluorescence emitted from the sample; A second optical element provided in the sample space; and Further comprising: An optical device in which, when the sample is placed on the stage and defects of the sample are detected, the air pressure in the second space is controlled to be lower than the air pressure in the first space and the air pressure in the third space, and the light irradiated from the light irradiation device passes through the first optical element and the second optical element, enters the sample space from the first space, and reaches the sample.

20. A charged particle beam device including the optical device according to claim 19, a first sealing window attached to a portion of the first container part and capable of transmitting the light; a second sealing window attached to a portion of the second container part and capable of transmitting the light; an electron beam column provided in the sample space and capable of irradiating an electron beam; Further comprising: while the sample space is maintained in vacuum, the light can enter the first space from the third space by transmitting through the first sealing window, and can enter the sample space from the first space by transmitting through the second sealing window, A charged particle beam device, wherein the stage can move within the sample space between a position where the light reaches and a position where the electron beam is irradiated.

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