JP2007286162A - Immersion microscopic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce contamination caused by bacteria during immersion observation. <P>SOLUTION: The immersion microscopic device has: a support means 22 supporting a substrate 10A to be observed; an objective 23 of an immersion system; and supply means 24 and 31 partially supplying liquid circulating in a circulation path 30 for liquid for immersion observation to space between the edge of the objective 23 and the substrate 10A through a branch pipe 50 branching off from the circulation path 30. The liquid circulating in the circulation path 30 is made to flow in the branch pipe 50 by the supply means 24 and 31, and also the liquid in the branch pipe 50 is discharged to the outside by a liquid suction device 40 so that residual liquid may be exchanged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an immersion microscope apparatus that performs immersion observation of a substrate.

In order to observe defects and foreign matter on circuit patterns formed on a substrate (for example, a semiconductor wafer or a liquid crystal substrate) with high resolution, an immersion objective lens is used, and the gap between the tip of the objective lens and the substrate is used. It has been proposed to fill with a liquid such as water and increase the numerical aperture of the objective lens according to the refractive index (> 1) of the liquid (see, for example, Patent Document 1). It has also been proposed to automatically supply liquid from a liquid supply device.
JP 2005-83800 A

  However, there is a problem that bacteria are generated in the liquid in the liquid supply apparatus, and the substrate and the objective lens are contaminated by the bacteria. For example, contamination caused by bacterial colonies formed over time attached to a substrate or objective lens as fine particles. Although it is conceivable to circulate the liquid in the liquid supply device as a measure against bacteria, the liquid stagnates in the branch branching from this circulation path to the supply opening, so that the generation of bacteria can be suppressed. Can not. For this reason, bacterial contamination cannot be reduced only by circulating the liquid. Such a problem is not limited to the case of observing in the state of local immersion, but may occur in the same way when observing in the state of immersion on the entire surface.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an immersion microscope apparatus that can reduce contamination by bacteria during immersion observation.

  In order to achieve such an object, an immersion microscope apparatus according to the present invention includes a support unit that supports a substrate to be observed, and an immersion objective lens that performs immersion observation on the substrate supported by the support unit. Supply means for supplying a part of the liquid as a liquid for immersion observation between the objective lens and the substrate from the circulation path through which the predetermined liquid circulates, and the supply means is provided to be branched from the circulation path. A branch pipe connected between the objective lens and the substrate, and a part of the liquid circulating in the circulation path is supplied between the objective lens and the substrate via the branch pipe, and the supply means is operated. Thus, a part of the liquid circulating in the circulation path is caused to flow into the branch pipe, and the liquid remaining on the downstream side of the branch pipe is discharged to the outside to replace the residual liquid.

  In the above-described invention, it is preferable that the residual liquid replacement means replace the residual liquid during the initialization operation after the apparatus power is turned on in the immersion microscope apparatus.

  Furthermore, in the above-described invention, it is preferable that the residual liquid exchange unit exchanges the residual liquid again after a predetermined time has elapsed since the residual liquid exchange unit exchanged the residual liquid.

  In the above-described invention, the branch pipe includes a first branch pipe disposed on the objective lens side and a second branch pipe disposed on the circulation path side of the first branch pipe and having a cross-sectional area larger than that of the first branch pipe. Preferably, the residual liquid exchanging means is configured to have a drainage branch pipe that is branched from the second branch pipe and discharges the liquid remaining in the second branch pipe to the outside.

  Furthermore, in the above-mentioned invention, it is preferable that the residual liquid exchanging means has a liquid recovery part that discharges the liquid in the branch pipe discharged to the objective lens side to the outside.

  According to the present invention, contamination by bacteria during immersion observation can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the immersion microscope apparatus 1 of the present embodiment is mainly composed of a mini-environment apparatus 10 and an immersion microscope 20 installed therein. Here, FIG. 1A is a top view of the immersion microscope apparatus 1, and FIG. 1B is a cross-sectional view of the immersion microscope apparatus 1. Inside the mini-environment apparatus 10, there is also provided a transport mechanism 16 that automatically transports the observation target substrate 10A. The substrate 10A is a semiconductor wafer, a liquid crystal substrate, or the like. The immersion microscope apparatus 1 is an apparatus that performs immersion observation (appearance inspection) of defects and foreign matters on a circuit pattern formed on the substrate 10A in a manufacturing process of a semiconductor circuit element or a liquid crystal display element. The circuit pattern is, for example, an etching pattern.

  The mini-environment device 10 includes a housing 11 and a plurality of fan filter units 12 to 15 installed on the upper surface thereof. The fan filter units 12 to 15 are mechanisms for removing clean air particles such as dust and dust from ambient air (in a clean room) and then introducing clean air into the housing 11 (FFU; FAN FILTER UNIT). A vent (not shown) is formed on the lower surface of the housing 11 so that the downflow from the fan filter units 12 to 15 can be exhausted to the outside (in the clean room). The arrows in FIG. 1 represent the air flow.

  Thus, the inside of the housing 11 of the mini-environment device 10 is a local environment (minienvironment) in which the cleanliness is higher than that of the surroundings (in the clean room) in order to perform immersion observation of the substrate 10A in a clean environment. . The removal of particles in the gas is performed by the ULPA filter 17. Also, clean air from which chemical substances (organic gas, ammonia gas, etc.) have been removed by the chemical filter 18 of the fan filter unit 12 is introduced into the space inside the housing 11 where the immersion microscope 20 is disposed. It is kept in an environment with little outgas such as TOC (Total Organic Carbon).

  In the immersion microscope 20, stages 21 and 22 (support means) for supporting the substrate 10A, an immersion objective lens 23, and a discharge nozzle 24 used when discharging a liquid for immersion observation (not shown). (Supplying means) and a suction nozzle 25 used for sucking the liquid are provided. Although not shown, the immersion microscope 20 is also provided with an illumination optical system, a TTL autofocus mechanism, a control unit, and the like.

  The stages 21 and 22 include an XY stage 21 and a Zθ stage 22. The substrate 10A is conveyed from, for example, a developing device and placed on the upper surface of the Zθ stage 22, and is fixedly supported by, for example, vacuum suction. The Zθ stage 22 moves the substrate 10A in the vertical direction when the substrate 10A is focused. The focusing operation is performed by a control unit (not shown) using an autofocus mechanism. Further, when positioning a predetermined observation point of the substrate 10A within the field of view of the objective lens 23, the XY stage 21 moves the substrate 10A within a horizontal plane. The base member of the XY stage 21 is fixed to the main body of the immersion microscope 20.

  The immersion objective lens 23 is fixed to the main body of the immersion microscope 20, and when the space between the tip and the substrate 10A is filled with the liquid 19 (see FIG. 2) of the immersion medium, the aberration of the optical system. Is designed to be corrected. The illumination optical system (not shown) is provided with an illumination light source. The observation wavelength is, for example, a visible region or an ultraviolet region. In the visible range, immersion observation of the substrate 10A using an eyepiece can be performed. In the ultraviolet region, visual observation is not possible, so a CCD camera or the like is provided in place of the eyepiece to take an image and display on a monitor device for immersion observation.

  The liquid 19 of the immersion medium is pure water, for example. Pure water can be easily obtained in large quantities in a semiconductor manufacturing process or the like. Further, since there is no adverse effect on the photoresist of the substrate 10A, non-destructive inspection of the substrate 10A is possible. In addition, pure water has no adverse effect on the environment, and since the content of impurities is extremely low, an effect of cleaning the surface of the substrate 10A can be expected. The pure water used in the semiconductor manufacturing process is generally called “ultra pure water”. This is more pure than what is commonly referred to as “pure water”. Also in this embodiment, it is more preferable to use ultrapure water.

  Each of the discharge nozzle 24 and the suction nozzle 25 is fixedly disposed around the objective lens 23, and the tip thereof is positioned in the vicinity of the tip of the objective lens 23. Further, the tips of the discharge nozzle 24 and the suction nozzle 25 are arranged so as to face each other with the tip of the objective lens 23 interposed therebetween. Further, the discharge nozzle 24 and the suction nozzle 25 are disposed so as to be inclined so that the extension lines of the respective central axes intersect on the focal plane of the objective lens 23. The central axes of the discharge nozzle 24 and the suction nozzle 25 are included in the same plane together with the optical axis of the objective lens 23.

  In order to discharge an appropriate amount of liquid 19 between the tip of the objective lens 23 and the substrate 10A using the discharge nozzle 24, the discharge nozzle 24 is provided with a liquid discharge device 31 (supply means) as shown in FIG. The circulation path 30 of ultrapure water is connected. The liquid discharge device 31 is provided with a liquid discharge valve (not shown) and a water pressure regulator. The ultrapure water circulation path 30 is provided with a final filter 32, an ultrapure water production apparatus 33, and a liquid tank 34.

  In the ultrapure water circulation path 30, pure water is injected into the liquid tank 34, the pure water in the liquid tank 34 is pumped up by the pump of the ultrapure water production apparatus 33, ion removal and bacteria sterilization are performed, and then the final process is performed. It is sent to the filter 32. Then, after passing through the final filter 32, ultrapure water that satisfies water quality specifications such as particles is obtained. This ultrapure water is sent again to the liquid tank 34 until a discharge command is issued from a control unit (not shown), and circulates between the liquid tank 34, the ultrapure water production apparatus 33, and the final filter 32. Become. Circulation is managed with a timer.

  When a discharge command is issued from a control unit (not shown), a part of the ultrapure water is sent from the final filter 32 of the ultrapure water circulation path 30 to the liquid discharge device 31. In the liquid discharge device 31, this ultrapure water is supplied to the liquid discharge valve with a water pressure controlled by a water pressure regulator, and the observation point (immersion objective lens 23) of the substrate 10 </ b> A from the liquid discharge valve via the discharge nozzle 24. Between the front end of the substrate and the substrate 10A).

  As described above, the immersion microscope apparatus 1 according to the present embodiment uses the ultrapure water circulation path 30, the liquid discharge apparatus 31, and the discharge nozzle 24 to automatically start from the supply opening located at the tip of the discharge nozzle 24. Thus, the liquid 19 for immersion observation can be supplied. The liquid 19 is supplied through a branch pipe 50 branched from the ultrapure water circulation path 30 (that is, a pipe from the use point 35 to the tip of the discharge nozzle 24). Then, immersion observation of the substrate 10A is performed in a state of local immersion in which the liquid 19 is locally supplied. Note that, as described above, when the liquid ejection device 31 is actuated by an ejection command from a control unit (not shown), a part of ultrapure water circulating in the circulation path 30 flows through the branch pipe 50 and the immersion objective lens 23. However, when the operation of the liquid discharge device 31 is stopped by a discharge stop command from the control unit, the supply of the liquid 19 is stopped and ultrapure water from the circulation path 30 is supplied to the branch pipe 50. It remains inside (and between the tip of the immersion objective lens 23 and the substrate 10A).

  Thereafter, when the immersion observation at a certain observation point is completed, the liquid 19 is sucked. In order to suck the liquid 19 from the substrate 10 </ b> A using the suction nozzle 25, a liquid suction device 40 (liquid recovery unit) is connected to the suction nozzle 25. The liquid suction device 40 is mainly composed of a liquid recovery filter 41, electromagnetic valves 42 and 43, and a vacuum regulator 44. A vacuum pump 44 is connected to the vacuum regulator 44.

  In the liquid suction device 40, the suction of the liquid 19 is started by operating the suction pump connected to the vacuum regulator 44 and opening the electromagnetic valve 43. Air from the surroundings is taken into the suction nozzle 25, and the liquid 19 is sucked together with the flow of air. Then, the liquid 19 sucked by the suction nozzle 25 is separated from the air through the liquid recovery filter 41 and drained to the outside through the electromagnetic valve 42.

  In the immersion microscope apparatus 1 of the present embodiment, since the supply / recovery of the liquid 19 is automatically controlled during the immersion observation, there is almost no burden on the operator, and the substrate 10A can be observed with high throughput. it can. Note that when the ultrapure water in the liquid tank 34 is used as the liquid 19 for immersion observation and the liquid tank 34 approaches the sky, this is detected by a sensor (not shown), and new pure water is automatically supplied to the liquid. It is injected into the tank 34.

  By the way, in the immersion microscope apparatus 1 of the present embodiment, the ultrapure water circulation path 30 is provided as a measure against bacteria, but the branch pipe 50 branched from the circulation path 30 (that is, from the use point 35 to the tip of the discharge nozzle 24). Since the liquid stays inside the tube, the generation of bacteria cannot be suppressed. In order to prevent the substrate 10A and the objective lens 23 from being contaminated by bacteria generated in the branch pipe 50, in the immersion microscope apparatus 1 of the present embodiment, a predetermined time has elapsed during the initialization operation or from the end of the initialization operation. When the liquid discharge device 31 and the liquid suction device 40 are actuated automatically or at an appropriate timing such as in the middle of repetition of immersion observation, the branch pipe 50 (from the use point 35 to the tip of the discharge nozzle 24 is automatically The liquid remaining in the tube) is discharged to the outside.

  At this time, a new liquid (a liquid in which no bacteria are generated) flows into the branch pipe 50 from the circulation path 30 by the operation of the liquid discharge device 31. That is, a part of ultrapure water circulating in the circulation path 30 is caused to flow into the branch pipe 50 by the operation of the liquid discharge device 31, and an old liquid (bacteria is generated on the downstream side of the branch pipe 50 by the operation of the liquid suction device 40. The liquid that may have been removed) is discharged to the outside, and the residual liquid in the branch pipe 50 is replaced (replaced) with a new liquid. That is, the liquid ejecting device 31, the liquid sucking device 40, and a control unit (not shown) that controls the operation of the liquid ejecting device 31 and the liquid sucking device 40 are mainly used to exchange the liquid remaining in the branch pipe 50. Residual liquid exchange means will be constructed. Such replacement (replacement) of the liquid is preferably performed periodically according to the generation state of bacteria and the acceptable water quality (or according to the pattern pitch on the substrate 10A).

  As shown in FIG. 2, the branch 50 is composed of only one type of branch pipe (with the same cross-sectional area) (between the discharge nozzle 24 and the use point 35), and as shown in FIG. 6, the first branch 51 There are cases where the configuration is divided into (between the discharge nozzle 24 and the branch 37) and the second branch pipe 52 (between the branch 37 and the use point 35). In the case of FIG. 6, the cross-sectional area of the second branch pipe 52 is set to be larger than the cross-sectional area of the first branch pipe 51. Therefore, by draining the water in the second branch pipe 52 from the drainage branch pipe 53 branched from the second branch pipe 52 to the outside, it is possible to shorten the time required for drainage.

  The drainage branch pipe 53 is provided with an electromagnetic valve 45. In the case of FIG. 6, the above-described liquid discharge valve 38 constituting the liquid discharge device 31 is disposed in the first branch pipe 51, and the above-described water pressure regulator 36 constituting the liquid discharge apparatus 31 is provided in the second branch pipe 52. It is arranged.

  Next, a sequence (flow) for replacing the residual liquid in the branch pipe 50 with a new liquid will be described with reference to FIGS. 7 and 8. Here, FIG. 7 shows a sequence in the case where the branch pipe 50 is composed of only one kind of branch pipe, and FIG. 8 shows a sequence in a case where the branch pipe 50 is composed of the first branch pipe 51 and the second branch pipe 52. .

  In the sequence shown in FIG. 7, first, when the apparatus power is turned on (power ON), the immersion microscope apparatus 1 of the present embodiment is activated by the power ON, and a predetermined initialization operation is performed. When the apparatus is activated by turning on the power, bacteria are expected to be generated from the liquid remaining in the branch pipe 50.

  Therefore, during the initialization operation in the immersion microscope apparatus 1, in step S <b> 101, the liquid in the branch pipe 50 is discharged from the discharge nozzle 24 by the operation of the liquid discharge apparatus 31 and is discharged from the discharge nozzle 24 by the operation of the liquid suction apparatus 40. The liquid is discharged to the outside of the apparatus, and the residual liquid in the branch pipe 50 is replaced with a new liquid.

  After the residual liquid in the branch pipe 50 is replaced with a new liquid, in step S102, time counting is started by a timer (not shown).

  Next, when an end switch (not shown) is operated in step S103, the power is turned off and the operation of the immersion microscope apparatus 1 is ended. On the other hand, if the end switch is not operated, the process proceeds to step S104, and when a predetermined time (for example, 1 hour) elapses after the remaining liquid in the branch pipe 50 is replaced with a new liquid in step S101 by counting the timer, Returning to step S101, the remaining liquid in the branch pipe 50 is replaced with a new liquid again.

  The sequence shown in FIG. 8 is the same sequence as in the case of FIG. 7 from step S101 to step S104, and the description from step S101 to step S104 is omitted. In the case illustrated in FIG. 8, when a predetermined time (for example, 1 hour) elapses after the remaining liquid in the branch pipe 50 is replaced with a new liquid in Step S101 by counting the timer in Step S104, the process proceeds to Step S105.

  In step S <b> 105, the liquid in the second branch pipe 52 is discharged from the branch 37 to the outside through the drainage branch pipe 53 by the operation of the liquid discharge device 31 and the electromagnetic valve 45. Then, returning to step 101, the liquid in the branch pipe 50 (in this case, the first branch pipe 51) is discharged from the discharge nozzle 24 again by the operation of the liquid discharge device 31 and discharged from the discharge nozzle 24 by the operation of the liquid suction device 40. The discharged liquid is discharged to the outside of the apparatus, and the remaining liquid in the branch pipe 50 is replaced with a new liquid. In the case of FIG. 8, since it can drain in large quantities with the 2nd branch pipe 52, the time concerning draining can be shortened.

  Further, when the old liquid remaining in the branch pipe 50 is discharged, it is necessary to prevent troubles of the apparatus (for example, electric troubles or rust of the stages 21 and 22) from occurring with this liquid. For this reason, in the present embodiment, as shown in FIGS. 2 and 3, an opening 26 for drainage is provided at the center of the upper surface of the Zθ stage 22 (the mounting surface of the substrate 10 </ b> A), and the opening 26. Is connected to the liquid suction device 40 by a pipe 27. The size of the opening 26 is larger than the supply opening located at the tip of the discharge nozzle 24. The pipe 27 has the same inclination as the discharge nozzle 24 in the vicinity of the opening 26.

  The stages 21 and 22 are driven in a state where the substrate 10A is removed from the upper surface of the Zθ stage 22, and the discharge nozzle 24 is moved at least in the vertical direction (the optical axis direction of the objective lens 23). It is made to oppose with the opening part of the front-end | tip (refer FIG. 4). At this time, it is preferable that the central axis of the pipe 27 in the vicinity of the opening 26 coincides with the extended line of the central axis of the discharge nozzle 24.

  In this state, a control unit (not shown) as a residual liquid exchange means operates the liquid discharge device 31 to continuously send a predetermined amount of new liquid from the circulation path 30 into the branch pipe 50. Thus, the old liquid remaining in the branch pipe 50 is continuously discharged from the opening at the tip of the discharge nozzle 24 toward the drain opening 26 and discharged from the drain opening 26. At the same time, the liquid suction device 40 is operated to suck the liquid remaining in the branch pipe 50, thereby discharging it from the drain opening 26 to the outside through the pipe 27.

  In order to confirm that all the old liquid remaining in the branch pipe 50 has been completely discharged (that is, all the liquid in the branch pipe 50 has been replaced with a new one), a flow meter or the like is placed in the middle of the branch pipe 50 or the pipe 27, for example. It is preferable to provide a sensor for measuring the amount of liquid. In addition, when the discharge flow rate, speed, and water pressure are maintained at predetermined constant values, the amount of liquid may be grasped by measuring the elapsed time from the start of discharge, and the same confirmation may be performed. . Furthermore, in order to ensure that the liquid in the branch pipe 50 discharged from the discharge nozzle 24 is discharged from the drain opening 26, the substrate is placed on the upper surface of the Zθ stage 22 (the mounting surface of the substrate 10A). When 10A is placed, the fact may be notified by notifying means (not shown).

  As described above, according to the immersion microscope apparatus 1 of the present embodiment, the liquid (non-circulating liquid) in the branch pipe 50 branched from the circulation path 30 is discharged at an appropriate timing, and a new liquid is circulated. Since the sample is taken into the branch pipe 50 from 30, contamination by bacteria at the time of immersion observation can be reduced. Therefore, it is possible to satisfactorily observe the immersion of a fine pattern. Further, a liquid discharge opening 26 larger than the opening at the tip of the discharge nozzle 24 is used, and the liquid in the branch pipe 50 is discharged from the opening 26 in a state where the opening 26 is opposed to the supply opening. Therefore, the trouble of the device due to the liquid does not occur.

  By exchanging the residual liquid in the branch pipe 50 as a preparation at the time of initialization of the apparatus, the liquid for immersion observation can be brought into a clean state. Further, the same operation may be performed in the middle of the repetition of the immersion observation, or the same operation may be performed again in preparation for the resumption of the immersion observation when a predetermined time has elapsed from the previous operation. Therefore, the liquid (non-circulating liquid) in the branch pipe 50 branched from the circulation path 30 can always be kept clean, and the generation of bacteria can be prevented in advance.

  Furthermore, in the immersion microscope apparatus 1 according to the present embodiment, the liquid remaining in the branch pipe 50 is discharged from the opening 26 provided in the vicinity of the distal end side of the objective lens 23, so that the discharging operation can be performed quickly. Can be done efficiently. Further, in the immersion microscope apparatus 1 of the present embodiment, when the liquid remaining in the branch pipe 50 is sucked, the suction force of the liquid suction apparatus 40 for immersion observation is used, so that a suction apparatus dedicated to discharge is used. There is no need to provide a separate device, and the enlargement of the apparatus can be avoided.

  Furthermore, in the immersion microscope apparatus 1 of the present embodiment, the drainage opening 26 is provided on the upper surface of the Zθ stage 22, so that the opening 26 is utilized using the drive mechanism of the Zθ stage 22 during the discharge operation. Can be opposed to the opening at the tip of the discharge nozzle 24. For this reason, it is not necessary to provide a separate drive mechanism exclusively for discharging, and the enlargement of the apparatus can be avoided. Further, since the drain opening 26 is provided on the upper surface of the Zθ stage 22, the discharging operation can be performed at almost the same stage position as in the immersion observation. For this reason, it is not necessary to increase the stroke of the Zθ stage 22 for the discharging operation, and the enlargement of the apparatus can be avoided.

  In the embodiment described above, the drain opening 26 is provided on the upper surface of the Zθ stage 22, but the present invention is not limited to this. For example, as shown in FIG. 5, a table 28 may be fixedly provided near the outside of the Zθ stage 22, and a similar drainage opening may be provided on the upper surface of the table 28 (not shown in FIG. 5). To do). Even in this case, the drainage opening can be opposed to the opening at the tip of the discharge nozzle 24 by using the drive mechanism of the Zθ stage 22. In this way, since there is an opening for draining outside the Zθ stage 22, the liquid remaining in the branch pipe 50 is discharged while the substrate 10 </ b> A is placed on the upper surface of the Zθ stage 22. (Exchange) can be performed.

  Furthermore, not only the table 28 fixed to the Zθ stage 22, but also a drain opening may be provided on an external table provided separately from the Zθ stage 22. Even in this case, since there is an opening for drainage outside the Zθ stage 22, the liquid remaining in the branch pipe 50 is discharged while the substrate 10 </ b> A is placed on the upper surface of the Zθ stage 22. (Exchange) can be performed. However, a drive mechanism for moving the drainage opening at least in the vertical direction is required.

  In the immersion microscope apparatus 1 of the present embodiment, the old liquid is sucked using the suction force of the liquid suction apparatus 40 during the discharging operation of the old liquid remaining in the branch pipe 50. It is not limited to this. For example, an electromagnetic valve is provided in each of the pipelines connected to the suction nozzle 25 and the drainage opening 26 so that the suction from the suction nozzle 25 and the suction from the drainage opening 26 are individually controlled. Alternatively, the old liquid may be sucked using a suction device different from the liquid suction device 40. Furthermore, the old liquid remaining in the branch pipe 50 may be discharged without performing suction using the liquid suction device 40 or another suction device. Even in this case, in order to avoid trouble of the apparatus, it is preferable to guide the liquid discharged from the drain opening to the outside of the apparatus through the same pipe as the pipe 27 described above.

  Furthermore, in the above-described embodiment, the liquid discharging operation is performed as a preparation at the time of initialization of the apparatus. However, separately from such a discharging operation, the planar portion of the Zθ stage 22 (around the drain opening 26) In addition, using the flat part of the table 28 in FIG. 5 (around the drainage opening), the liquid is discharged by the discharge nozzle 24 and the liquid is sucked by the suction nozzle 25 as in the case of immersion observation. The branch pipe 50 may be completely filled with (new) liquid. By performing such an operation immediately before the immersion observation, it is possible to accurately control the liquid discharge amount during the immersion observation.

  Moreover, in the above-mentioned embodiment, although the example which discharges the liquid remaining in the branch pipe 50 from the opening part for drainage was demonstrated, you may perform the discharge operation | movement of a liquid as follows. That is, even if the discharge operation is performed little by little while repeating the discharge of the liquid by the discharge nozzle 24 and the suction of the liquid by the suction nozzle 25 in the same manner as in the immersion observation, using an arbitrary plane different from the substrate 10A. Good. However, if the liquid is discharged from the drain opening, the time until the discharge is completed is shorter.

  When a plane different from the substrate 10A is used, it is conceivable to use a flat table portion (a portion where the drainage opening 26 is omitted) at the center of the upper surface of the Zθ stage 22 as the plane. Furthermore, a tool substrate for drainage or the surface of a defective substrate may be used. In these cases, the discharging operation can be performed in the same environment as the immersion observation of the substrate 10A. In addition, the upper surface of the table 28 in FIG. 5 (the location where the drainage opening is omitted) or the upper surface of the table provided separately from the Zθ stage 22 may be used. In this case, the liquid discharge operation may be performed after moving the liquid discharge plane three-dimensionally so as to face the tips of the discharge nozzle 24 and the suction nozzle 25.

  Further, when there is no substrate 10A on the Zθ stage 22, a plane at the center of the upper surface of the Zθ stage 22 can be used, and therefore, the discharge nozzle 24 and the suction nozzle among the plane and the plane outside the Zθ stage 22 can be used. By selecting the one closer to 25, the throughput can be increased. Moreover, it is preferable to use a PEEK material, a SUS material after electrolytic polishing, a fluorine-based resin such as PTFE, or the like as a flat material for drainage. These materials have the advantage that it is difficult to leave a liquid, the elution of the material into the liquid is small, and bacteria are not easily attached.

  Furthermore, it is preferable to use a material having a higher liquid wettability than the tip of the objective lens 23 (a material having a small surface tension and a small contact angle) as the drainage flat material. As a result, the liquid tends to adhere to the drainage plane, and the adhesion of the liquid to the objective lens 23 can be reduced.

  Furthermore, in the above-described embodiment, the case where the substrate 10A is observed in the state of local liquid immersion has been described. Can be applied.

(A) is a top view of the immersion microscope apparatus, and (b) is a cross-sectional view of the immersion microscope apparatus. It is a figure which shows the structure of the liquid discharge apparatus connected to the discharge nozzle, the circulation path, and the liquid suction apparatus connected to the suction nozzle. It is a figure explaining the opening part and piping for drainage provided in the upper surface of a Z (theta) stage. It is a figure explaining the state at the time of discharging | emitting the liquid left in the branch pipe. It is a figure explaining the table fixed to the Z (theta) stage. It is a figure which shows the structure in case a branch pipe is comprised from a 1st branch pipe and a 2nd branch pipe. It is a flowchart figure explaining a sequence in case a branch pipe is comprised only with one kind of branch pipe. It is a flowchart figure explaining a sequence in case a branch pipe is comprised from a 1st branch pipe and a 2nd branch pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Immersion microscope apparatus 10A Substrate 19 Liquid 20 Immersion microscope 21 XY stage (support means) 22 Zθ stage (support means)
DESCRIPTION OF SYMBOLS 23 Objective lens 24 Discharge nozzle (supply means) 25 Suction nozzle 26 Opening part for drainage 27 Piping 30 Circulation path 31 Liquid discharge apparatus (supply means)
35 Use points 36 Water pressure regulator 37 Branch 38 Liquid discharge valve 40 Liquid suction device (liquid recovery part)
50 Branch pipe 51 First branch pipe 52 Second branch pipe 53 Drainage branch pipe

Claims (5)

Supporting means for supporting the substrate to be observed;
An immersion objective lens for performing immersion observation on the substrate supported by the support means;
Supply means for supplying a part of the liquid as a liquid for immersion observation between the objective lens and the substrate from a circulation path through which the predetermined liquid circulates;
The supply means has a branch pipe that is branched from the circulation path and is connected between the objective lens and the substrate, and a part of the liquid circulating in the circulation path is passed through the branch pipe to the objective lens. And between the substrate and the substrate,
There is a residual liquid exchanging means for exchanging the residual liquid by operating the supply means to flow a part of the liquid circulating in the circulation path into the branch pipe and discharging the liquid remaining downstream from the branch pipe to the outside. An immersion microscope apparatus characterized by being configured as described above.   2. The immersion microscope apparatus according to claim 1, wherein the residual liquid replacement unit replaces the residual liquid during an initialization operation after the apparatus power is turned on in the immersion microscope apparatus.   3. The immersion microscope according to claim 1, wherein the residual liquid replacement unit replaces the residual liquid again after a predetermined time has elapsed since the residual liquid replacement unit replaced the residual liquid. 4. apparatus. The branch pipe is a first branch pipe disposed on the objective lens side;
The first branch pipe is arranged on the circulation path side and has a second branch pipe having a cross-sectional area larger than the first branch pipe,
The residual liquid exchanging means includes a drainage branch pipe that is branched from the second branch pipe and discharges the liquid remaining in the second branch pipe to the outside. The immersion microscope apparatus according to any one of claims 1 to 3.   The said residual liquid exchange means has a liquid collection | recovery part which discharge | emits the liquid in the said branch pipe discharged | emitted by the said objective lens side outside, It is comprised among Claims 1-4 characterized by the above-mentioned. The immersion microscope apparatus according to any one of the above.

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