JP2007133077A - Immersion objective lens-barrel and liquid immersion microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely collect a liquid supplied on a specimen face concerning a liquid immersion objective lens-barrel and a liquid immersion microscope used to be filled with the liquid between a lens part of the objective lens-barrel and a specimen. <P>SOLUTION: The liquid immersion objective lens-barrel comprises a liquid supply means for supplying the liquid between the lens part of the edge of the objective lens-barrel and the specimen, and a liquid suction means for sucking the liquid between the lens part and the specimen. The liquid suction means has a suction opening for sucking the liquid, a liquid reservoir part for reserving the liquid from the suction opening, and a suction pipe part for sucking the liquid of the liquid reservoir part. The passage cross sectional area of the liquid reservoir part is larger than that of the suction pipe part, and the passage cross sectional area of the suction pipe part is equal to or larger than the area of the suction opening. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an immersion objective lens barrel and an immersion microscope that are used by filling a space between a lens portion of an objective lens barrel and a sample with a liquid.

2. Description of the Related Art Conventionally, an immersion microscope that is used by filling a space between a lens portion of an objective lens barrel and a sample with a liquid is known. In such an immersion microscope, the resolution of the detection optical system can be improved by increasing the effective NA (Numerical Aperture).
JP 2005-83800 A

However, in the conventional immersion microscope, it is difficult to reliably recover the liquid supplied to the sample surface. For example, when the sample is a wafer, particles of 0.1 μm or less floating in the air are liquid. There is a problem that the wafer adheres to the surface and contaminates the wafer, or the liquid is oxidized by the liquid.
The present invention has been made to solve such a conventional problem, and an object thereof is to provide an immersion objective lens barrel and an immersion microscope that can reliably recover the liquid supplied to the sample surface. To do.

  An immersion objective lens barrel according to a first aspect of the present invention is a liquid supply means for supplying a liquid between a lens portion at a tip of an objective lens barrel and a sample, and the liquid between the lens portion and the sample Liquid suction means for sucking, wherein the liquid suction means is a suction port for sucking the liquid, a liquid reservoir portion for storing the liquid from the suction port, and a suction conduit for sucking the liquid in the liquid reservoir portion The passage cross-sectional area of the liquid reservoir is larger than the cross-sectional area of the suction pipe section, and the cross-sectional area of the suction pipe section is the same as or larger than the area of the suction port. It is characterized by.

The immersion objective lens barrel according to a second aspect of the invention is the immersion objective lens barrel according to the first aspect of the invention, wherein the suction port is opened at the tip of the nozzle portion, and the nozzle portion is connected to the liquid reservoir portion. It is characterized by.
An immersion objective lens barrel according to a third aspect is the immersion objective lens barrel according to the first or second aspect, wherein the area of the suction port is larger than a cross-sectional area in a direction perpendicular to the liquid suction direction. It is large.

The immersion objective lens barrel according to a fourth aspect of the present invention is the immersion objective lens barrel according to any one of the first to third aspects, wherein the suction port has a width in a direction perpendicular to the liquid suction direction. It is characterized by being larger than the width.
An immersion objective lens barrel according to a fifth invention is the immersion objective lens barrel according to any one of the second to fourth inventions, wherein the nozzle portion is disposed outside the lens portion of the objective lens barrel. The suction member disposed so as to cover the inclined portion is formed by a recess formed on the inclined portion side and a space formed between the inclined portion, and the liquid reservoir and the suction member are formed on the suction member. A suction conduit portion is formed.

The immersion objective lens barrel according to a sixth aspect of the present invention is the immersion objective lens barrel according to any one of the second to fourth aspects, wherein the liquid suction means comprises a tube member, and the tube member The suction port, the nozzle part, the liquid reservoir part, and the suction pipe part are formed sequentially.
An immersion microscope according to a seventh aspect has the immersion objective lens barrel according to any one of the first to sixth aspects.

  In the immersion objective lens barrel and the immersion microscope of the present invention, a liquid reservoir is provided between the suction port and the suction conduit, and the passage sectional area of the reservoir is larger than the passage sectional area of the suction conduit. In addition, since the cross-sectional area of the suction pipe portion is the same as or larger than the cross-sectional area of the suction port, the liquid supplied to the sample surface can be reliably recovered.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows a semiconductor defect inspection apparatus using the immersion microscope of this embodiment.
This semiconductor defect inspection apparatus has an inspection chamber 13 and a transfer chamber 15 in the apparatus main body 11. An immersion microscope 17 is disposed in the examination room 13. The immersion microscope 17 has an eyepiece lens barrel 19 and an immersion objective lens barrel 21. A wafer stage 23 is disposed below the immersion objective lens barrel 21. The wafer stage 23 includes an XY stage 27 and a Zθ stage 29 that convey and position a wafer 25 that is a sample.

  An FFU (fan filter unit) 31 with a chemical filter is disposed in the upper portion of the inspection chamber 13. The FFU 31 with chemical filter includes a fan 33, a chemical filter 35, and a ULPA filter 37. Due to the chemical filter 35, the inside of the examination room 13 is locally T.P. O. It is maintained in an environment with little outgas such as C (Total Organic Carbon). Further, the ULPA filter 37 keeps the particles in the air to a minimum.

In the transfer chamber 15, a transfer robot 39 for transferring the wafer 25 from the outside into the inspection chamber 13 is disposed. In addition, an FFU 41 that does not include the chemical filter 35 is disposed in the upper portion of the transfer chamber 15. The ULPA filter 37 of the FFU 41 keeps the particles in the air in the transfer chamber 15 to a minimum.
FIG. 2 schematically shows a liquid supply piping system 43 that supplies liquid to the immersion objective lens barrel 21 and a liquid suction piping system 45 that sucks the supplied liquid.

  In this embodiment, ultrapure water is used as the immersion liquid. After entering the tank 47, the pure water is pumped up by a pump (not shown) of the ultrapure water production apparatus 49, and the ultrapure water production apparatus 49 performs ion removal and bacteria sterilization. The final filter 51 satisfies water quality specifications such as particles. The ultrapure water that has passed through the final filter 51 is circulated to the tank 47 until a discharge command is input. Accordingly, the ultrapure water is circulated in the tank 47 except when pure water is injected. Circulation is managed with a timer. When ultrapure water is used and the tank 47 approaches the sky, the sensor automatically injects pure water.

  At the time of discharge, a liquid 55 made of ultrapure water is supplied to the liquid discharge device 57 at a water pressure controlled by the water pressure regulator 53. The discharge water amount is managed by adjusting the stroke of the piston 59 of the liquid discharge device 57, the discharge time, and the water pressure. If the surface tension (contact angle) differs depending on the material of the sample, an appropriate amount of water can be automatically discharged according to the recipe.

The liquid 55 discharged from the liquid discharge device 57 is guided to the discharge nozzle 63 through the pipe 61, and is discharged between the front lens 65 at the tip of the immersion objective lens barrel 21 and the wafer 25 by the discharge nozzle 63. The In this state, observation with the immersion microscope 17 is performed.
After the observation is finished, the liquid suction device 67 is operated, and the suction pipe 73 connected to the joint 71 of the suction member 69 is connected to the vacuum source 75. By this connection, the liquid 55 between the front lens 65 at the tip of the immersion objective lens barrel 21 and the wafer 25 is sucked. The sucked liquid 55 passes through the filter of the liquid suction device 67 and is then drained.

FIG. 3 shows details of the immersion objective lens barrel 21 described above.
The immersion objective lens barrel 21 includes an objective lens barrel 77 and a suction member 69.
A front lens 65 is disposed at the tip of the objective lens barrel 77. The front lens 65 is disposed on the optical axis L. An inclined portion 77 a is formed outside the front lens 65 of the objective lens barrel 77. A suction member 69 is disposed so as to cover the inclined portion 77a.

The suction member 69 has a disk shape, and a circular blind hole 69a into which the distal end portion of the objective lens barrel 77 is fitted is formed on the upper surface. An annular portion 69b is formed outside the blind hole 69a. A cover 69c is formed below the blind hole 69a to cover the inclined portion 77a at the tip of the objective lens barrel 77.
Disposed below the suction member 69 is a discharge nozzle 63 for supplying an immersion liquid 55 between the front lens 65 at the tip of the objective lens barrel 77 and the wafer 25. As shown in FIG. 4, the discharge nozzle 63 is fixed to a groove 69 d formed in the annular portion 69 b of the suction member 69 by an attachment member 79. The tip of the discharge nozzle 63 extends to the vicinity of the front lens 65. The discharge nozzle 63 has a connection part 63b to which the nozzle part 63a and the pipe 61 are connected.

  As shown in FIG. 4, a notch 69 e is formed in the cover 69 c of the suction member 69. The notch 69e is formed along the direction of the discharge nozzle 63 at the center of the cover 69c and in the vicinity thereof. The notch 69e has a width W1 substantially the same as the diameter of the front lens 65. In this embodiment, the liquid 55 is discharged from the discharge nozzle 63 so that the width W2 of the liquid 55 discharged from the discharge nozzle 63 is smaller than the width W1 of the notch 69e.

5 to 7 show details of the suction member 69. 5 is a top view of the suction member 69, FIG. 6 is a cross-sectional view taken along line AA in FIG. 5, and FIG. 7 is a cross-sectional view taken along line BB in FIG.
As shown in FIG. 5, a recess 69f is formed on the upper surface of the cover 69c of the suction member 69 so as to be continuous with the notch 69e. As shown in FIG. 3, a nozzle portion 81 is formed by a space formed between the recess 69 f and the inclined portion 77 a of the objective lens barrel 77. As shown in FIG. 8A, a suction port 81a for sucking the liquid 55 is opened at the tip of the nozzle portion 81.

  The area S1 of the suction port 81a is larger than the cross-sectional area S2 in the direction perpendicular to the suction direction of the liquid 55, as schematically shown in FIG. Therefore, the liquid 55 can be effectively sucked without causing large deformation of the liquid 55. When the area S1 of the suction port 81a is smaller than the cross-sectional area S2 in the direction perpendicular to the suction direction of the liquid 55, the liquid 55 is sucked into the suction port 81a while being largely deformed. The liquid 55 cannot be sucked effectively.

  Further, the width W3 of the suction port 81a is set larger than the width W2 in the direction perpendicular to the suction direction of the liquid 55, as schematically shown in FIG. More specifically, as shown in FIG. 5, the width W3 of the portion serving as the suction port 81a formed in the recess 69f of the suction member 69 is made larger than the width W1 of the notch 69e. Further, as shown in FIG. 4, the width W1 of the notch 69e is made larger than the width W2 in the direction perpendicular to the suction direction of the liquid 55. Therefore, the suction force from the suction port 81a can be applied to both side surfaces 55a of the liquid 55, and the liquid 55 can be quickly sucked into the suction port 81a. When the width W3 of the suction port 81a is smaller than the width W2 in the direction perpendicular to the suction direction of the liquid 55, the suction force from the suction port 81a cannot be applied to both side surfaces 55a of the liquid 55. 55 cannot be quickly sucked.

As shown in FIGS. 5 to 7, a liquid reservoir portion 69 h that stores the liquid 55 from the nozzle portion 81 is formed inside the annular portion 69 b of the suction member 69. An inclined surface 69i is formed on the outer side of the annular portion 69b. A screw hole 69j communicating with the liquid reservoir 69h is formed in the inclined surface 69i.
As shown in FIG. 3, the tip of the joint 71 is screwed into the screw hole 69j. The joint 71 is formed with a suction conduit 71a for sucking the liquid 55 in the liquid reservoir 69h. The passage sectional area of the suction pipe portion 71 a is the same as the passage sectional area of the suction pipe 73 connected to the rear end of the joint 71.

In the immersion objective lens barrel 21 described above, as schematically shown in FIG. 9, a liquid reservoir 69h is formed between the nozzle portion 81 and the suction conduit portion 71a. Therefore, when the suction pipe part 71a is connected to the vacuum source 75, the liquid 55 sucked into the suction port 81a moves through the nozzle part 81 to the liquid reservoir part 69h and then sucks through the suction pipe part 71a. Is done.
The passage cross-sectional area S3 of the liquid reservoir 69h is larger than the passage cross-sectional area S4 of the suction pipe portion 71a. Further, the passage cross-sectional area S4 of the suction pipe portion 71a is made larger than the area S1 of the suction port 81a formed at the tip of the nozzle portion 81. In this embodiment, the passage cross-sectional area on the tip side of the nozzle portion 81 is sequentially reduced by the taper portion 81b, and a suction port 81a is formed at the tip. Further, the passage cross-sectional area S5 on the liquid reservoir 69h side of the nozzle portion 81 is the same as or smaller than the passage cross-sectional area S4 of the suction pipe portion 71a.

  Therefore, at the time of suction of the liquid 55, the flow rate of the liquid 55 can be secured also in the nozzle portion 81 while maintaining the flow rate of the liquid 55 passing through the suction pipe portion 71a. Thereby, the flow rate of the liquid 55 at the nozzle portion 81 can be increased, and the liquid 55 supplied to the wafer 25 can be reliably recovered. When the passage cross-sectional area S3 of the liquid reservoir portion 69h is equal to or smaller than the passage cross-sectional area S4 of the suction pipe portion 71a, it is difficult to quickly move the liquid 55 from the nozzle portion 81 to the liquid reservoir portion 69h. Further, when the passage cross-sectional area S4 of the suction pipe portion 71a is smaller than the passage cross-sectional area S5 of the nozzle portion 81, it is difficult to increase the flow rate of the liquid 55 at the nozzle portion 81.

In this embodiment, since the liquid reservoir 69h is provided and the entire area of the opening on the liquid reservoir 69h side of the nozzle 81 is connected so as to be included in the liquid reservoir 69h, the nozzle 81 is flattened. Even when formed, the liquid 55 from the nozzle part 81 can be guided to the suction pipe part 71a without being restricted, and the flow rate of the liquid 55 passing through the nozzle part 81 can be ensured. That is, as shown in FIG. 10, when the nozzle part 81 is directly connected to the suction pipe part 71a without providing the liquid reservoir part 69h, at the hatched part D in FIG. Since the liquid 55 flowing into the portion 71a is throttled, it is difficult to ensure the flow rate of the liquid 55 passing through the nozzle portion 81. Further, the flow rate of the liquid 55 at the nozzle portion 81 becomes uneven, and it is difficult to perform smooth suction.
(Second Embodiment)
FIG. 11 shows a second embodiment of the immersion objective lens barrel of the present invention.

In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, an attachment member 83 is disposed so as to cover an inclined portion 77a formed outside the front lens 65 of the objective lens barrel 77.
The attachment member 83 has a disk shape, and a circular blind hole 83a into which the tip of the objective lens barrel 77 is fitted is formed on the upper surface. An annular portion 83b is formed outside the blind hole 83a. A cover 83c is formed below the blind hole 83a to cover the inclined portion 77a at the tip of the objective lens barrel 77.

  A discharge nozzle 63 that supplies liquid 55 for immersion is disposed between the front lens 65 at the tip of the objective lens barrel 77 and the wafer 25 below the attachment member 83. As shown in FIG. 12, the discharge nozzle 63 is fixed to a groove 83 d formed in the annular portion 83 b of the attachment member 83 by an attachment member 79. The tip of the discharge nozzle 63 extends to the vicinity of the front lens 65.

As shown in FIG. 12, a notch 83 e is formed in the cover 83 c of the mounting member 83. The notch 83e is formed along the direction of the discharge nozzle 63. The notch 83e has a width substantially the same as the diameter of the front lens 65.
A cutout groove 83 f is formed in the annular portion 83 b of the mounting member 83. And the pipe member 85 is arrange | positioned in this notch groove 83f. The pipe member 85 is fixed to the attachment member 83 by an attachment member (not shown).

A nozzle portion 85 a is formed at the tip of the tube member 85. A suction port 85b for sucking the liquid 55 is formed at the tip of the nozzle portion 85a. The nozzle portion 85a communicates with a liquid reservoir portion 85c that accumulates the liquid 55 from the suction port 85b. A suction conduit portion 85d for sucking the liquid 55 in the liquid reservoir portion 85c is communicated with the liquid reservoir portion 85c.
The passage cross-sectional area of the liquid reservoir 85c is made larger than the passage cross-sectional area of the suction pipe portion 85d. Further, the passage cross-sectional area of the suction pipe portion 85d is the same as or larger than the area of the suction port 85b. In this embodiment, the passage cross-sectional area of the nozzle portion 85a is the same as the area of the suction port 85b.

In this embodiment, when the suction conduit portion 85d is connected to the vacuum source 75, the liquid 55 sucked into the suction port 85b passes through the nozzle portion 85a and moves to the liquid reservoir portion 85c, and then the suction conduit portion 85d. Is sucked through.
Also in this embodiment, substantially the same effect as that of the first embodiment can be obtained.
(Supplementary items of the embodiment)
As mentioned above, although this invention was demonstrated by embodiment mentioned above, the technical scope of this invention is not limited to embodiment mentioned above, For example, the following forms may be sufficient.

(1) In the above-described embodiment, the example in which the suction ports 81a and 85b are formed at the tips of the nozzle portions 81 and 85a has been described. For example, as illustrated in FIG. The suction port 87c may be formed directly at the tip of the liquid reservoir 87b to be connected.
(2) In the above-described embodiment, the example in which the present invention is applied to the immersion microscope 17 of the semiconductor defect inspection apparatus has been described. However, the present invention can be widely applied to various apparatuses using the immersion microscope 17. it can.

It is explanatory drawing which shows the semiconductor defect inspection apparatus in which the immersion microscope of this invention is used. It is explanatory drawing which shows the liquid supply piping system and liquid suction piping system of the immersion microscope of FIG. FIG. 3 is an explanatory view showing the immersion objective lens barrel of FIG. 2. It is explanatory drawing which looked at FIG. 3 from the downward direction. It is a top view which shows the member for suction of FIG. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is explanatory drawing which shows the detail of the front-end | tip of the immersion objective lens-barrel of FIG. It is explanatory drawing which shows typically the relationship between a suction inlet, a nozzle part, a liquid reservoir part, and a suction conduit part. It is explanatory drawing for demonstrating an effect | action when not forming a liquid reservoir part. It is explanatory drawing which shows 2nd Embodiment of the immersion objective lens-barrel of this invention. It is explanatory drawing which looked at FIG. 11 from the downward direction. It is explanatory drawing which shows the other example of a pipe member.

Explanation of symbols

21: Immersion objective lens barrel, 25: Wafer, 55: Liquid, 63: Discharge nozzle, 65: Tip lens, 69: Suction member, 69f: Recess, 69h: Liquid reservoir, 71a: Suction conduit , 77: objective lens barrel, 77a: inclined part, 81: nozzle part, 81a: suction port, 85: pipe member, 85a: nozzle part, 85b: suction port, 85c: liquid reservoir part, 85d: suction pipe part .

Claims (7)

A liquid supply means for supplying a liquid between the lens portion at the tip of the objective lens barrel and the sample;
A liquid suction means for sucking the liquid between the lens portion and the sample;
With
The liquid suction means includes
A suction port for sucking the liquid;
A liquid reservoir for storing the liquid from the suction port;
A suction line section for sucking the liquid in the liquid reservoir;
Have
The passage sectional area of the liquid reservoir is made larger than the passage sectional area of the suction conduit, and the passage sectional area of the suction conduit is equal to or larger than the area of the suction port. Immersion objective lens barrel. The immersion objective lens barrel according to claim 1,
The immersion objective lens barrel, wherein the suction port is opened at a tip of a nozzle portion, and the nozzle portion is connected to the liquid reservoir portion. In the immersion objective lens barrel according to claim 1 or 2,
The immersion objective lens barrel characterized in that an area of the suction port is larger than a cross-sectional area in a direction perpendicular to a suction direction of the liquid. In the immersion objective lens barrel according to any one of claims 1 to 3,
An immersion objective lens barrel characterized in that a width of the suction port is larger than a width in a direction perpendicular to a suction direction of the liquid. In the immersion objective lens barrel according to any one of claims 2 to 4,
The nozzle portion is formed between a concave portion formed on the inclined portion side of the suction member disposed so as to cover an inclined portion outside the lens portion of the objective lens barrel and the inclined portion. An immersion objective lens barrel, wherein the immersion objective lens barrel is formed by a space and is formed by forming the liquid reservoir portion and the suction conduit portion on the suction member. In the immersion objective lens barrel according to any one of claims 2 to 4,
The liquid suction means comprises a pipe member, and the suction objective, the nozzle part, the liquid reservoir part, and the suction pipe part are sequentially formed in the pipe member. Tube. An immersion microscope comprising the immersion objective lens barrel according to any one of claims 1 to 6.

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