JP2000340153A - Charged particle beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a sample while maintaining the vacuum of a lens-barrel without providing a load locking chamber by moving a charged particle source and a lens-barrel of a beam device integrally in the direction of a first degree of freedom, and moving a sample in the direction of a degree of freedom different from the first degree of freedom. SOLUTION: This charged particle beam device irradiates charged particle beams onto an optional position of a sample 24 while differentially evacuating a sample chamber 14 and a lens-barrel chamber 15 or a charged particle source chamber. When charging the sample 24, a lens-barrel 17 is moved to the left in a major axis direction of an aperture 13 to press a fin 16 to a partition wall 12, and a differential part 28 and the aperture 13 are sealed with an O-ring 20. A small hole sealing mechanism 21 is pressed to the bottom part of the lens-barrel 17, and a small hole 19 constituting a differential part 29 is sealed with an O-ring 22. The sample chamber 14 is then opened to the atmosphere to change the sample 24, and the sample chamber 14 is evacuated again. When the degree of vacuum reaches 1×10-3 Pa, the aperture 13 and the small hole 19 are opened to make the differential parts 28, 29 function to resume the observation of the sample 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam apparatus, and more particularly to a scanning electron microscope (SEM) using a small cold cathode (emitter) as an electron source, a secondary ion mass spectrometer (SIMS), and the like. The present invention relates to a charged particle beam apparatus characterized in that it is configured to reduce the size of a sample chamber and eliminate a load lock chamber in a charged particle beam apparatus that irradiates the sample with a charged particle beam to observe and process the sample.

[0002]

2. Description of the Related Art Conventionally, a scanning charged particle beam apparatus for narrowly squeezing a charged particle beam emitted from a charged particle beam source such as a cold cathode and irradiating the sample with a beam is used for observation, exposure, analysis, inspection, recording, etc. Is widely used in many fields.

[0003] Such an electron beam device such as SEM or SI
Finely focused charged particle beam such as ion beam equipment such as MS
In a device that observes and processes a sample using a
Is for the purpose of degassing from the sample itself and processing with the beam
10 for the gas introduced ^-3Low vacuum of about Pa or more
It is common to have degrees.

On the other hand, in order to stably generate a charged particle beam, it is necessary to maintain a lens barrel composed of a charged particle source, an electromagnetic field lens, and the like at a high degree of vacuum of 10 ⁻⁵ to 10 ⁻⁷ Pa. For this purpose, a differential pumping system is employed in which a fixed partition having a small hole through which the charged particle beam passes is provided between the lens barrel and the sample chamber, and a separate pumping device is provided. Further, in such a conventional apparatus, an XY stage for moving the irradiation position of the sample immediately below the charged particle beam is provided in order to irradiate the charged particle beam passing through the small hole to an arbitrary position on the sample.

In order to increase the throughput of the charged particle beam apparatus, a load lock chamber having a small volume and a small internal surface area is provided separately from the sample chamber via a gate valve to avoid exposing the sample chamber to the atmosphere when the sample is replaced.

[0006]

However, when the sample chamber provided with the XY stage and the load lock chamber are combined,
The installation area of the device becomes very large, for example, 8
SE that can observe the entire surface of an inch (イ ン チ 20 cm) wafer
In the case of M, it can be easily understood that an installation area of at least 60 cm × 40 cm is required.

In recent years, with the advance of precision machining technology and the application of semiconductor processes, it has become possible to manufacture ultra-small charged particle sources and lens barrels. As the size of the sample increases, the size of the sample chamber and the load lock chamber provided with the XY stage moving mechanism increases.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a charged particle beam apparatus having a mechanism for reducing the size of a sample chamber and exchanging a sample while maintaining the degree of vacuum of a lens barrel without providing a load lock chamber. And

[0009]

FIG. 1 is an explanatory view of the principle configuration of the present invention. Referring to FIG. 1, means for solving the problems in the present invention will be described. In addition, FIG.
FIG. 2 is a schematic cross-sectional view near a boundary between a sample chamber and a column chamber of the charged particle beam device. FIG. 1 (1) The present invention relates to a charged particle beam apparatus that irradiates a charged particle beam 4 to an arbitrary position of a sample 7 while differentially exhausting a sample chamber 1 and a lens barrel chamber 2 or a charged particle source chamber. In addition, the charged particle source and the lens barrel 3 are integrally moved in the direction of the first degree of freedom, and the sample 7 is moved in the direction of a degree of freedom different from the first degree of freedom.

As described above, the charged particle source and the lens barrel 3 are integrally moved in the direction of the first degree of freedom,
Is moved in the direction of the degree of freedom different from the first degree of freedom, thereby enabling differential pumping. In addition, since the XY stage is not used, the size of the sample chamber 1 can be reduced. .

(2) The present invention according to the above (1), further comprising a sealing mechanism 9 for sealing an opening connected to the differential part 10 of the exhaust gas, so that the sample 7 can be replaced without providing a load lock chamber. It is characterized by the following.

As described above, by providing the sealing mechanism 9 for sealing the exhaust differential section 10, the sample chamber 1 can be exposed to the atmosphere while the lens barrel chamber 2 and the like are kept at a high vacuum.
The sample 7 can be replaced without providing a load lock chamber, so that the overall configuration of the device can be further reduced.

(3) The present invention is characterized in that, in the above (1) or (2), the movement of the sample 7 is a rotational movement about a normal line of the irradiation surface of the charged particle beam 4 as a rotation axis. And

As described above, the sample 7 without the XY stage is provided.
As the movement of the sample 7, a rotational motion having the normal to the irradiation surface of the charged particle beam 4 as a rotation axis is preferable in view of the shape of a typical semiconductor wafer as the sample 7. Since the space for moving the sample 7 is not required, the size of the sample chamber 1 can be further reduced.

(4) According to the present invention, in the above (3), the movement of the lens barrel 3 and the member integrated with the lens barrel 3 is a linear movement, and the opening connected to the differential portion 10 is formed. The small hole 8 that is configured and through which the charged particle beam 4 passes passes through the rotation axis of the sample 7.

As described above, by moving the lens barrel 3 and a member integrated with the lens barrel 3, that is, the fins 6 in a linear motion, one width of the apparatus can be reduced. It should be noted that the configuration of the opening connected to the differential section 10 and the passage of the small hole 8 through which the charged particle beam 4 passes through the rotation axis of the sample 7 means that the charged particle beam 4
This is a necessary condition for irradiation.

(5) In the present invention, in the above (3), the movement of the lens barrel 3 and the member integrated with the lens barrel 3 uses the normal line of the irradiation surface of the charged particle beam 4 as the rotation axis. The second rotary motion is an opening that is connected to the differential unit 10, and the small hole 8 through which the charged particle beam 4 passes passes through the rotation axis of the sample 7.

As described above, the movement of the lens barrel 3 and the member integrated with the lens barrel 3 is defined as the second rotational movement about the normal line of the irradiation surface of the charged particle beam 4 as the rotation axis. Cylinder 3
Since the space required for the movement of the member integrated with the device is not required, the device can be formed into a compact shape such as a circular or elliptical shape. In this case as well, by forming an opening connected to the differential unit 10 and allowing the small holes 8 through which the charged particle beam 4 passes to pass through the rotation axis of the sample 7, charging at all positions on the surface of the sample 7 is performed. This is a necessary condition for irradiating the particle beam 4.

In the above (4) or (5),
A seal that seals the opening connected to the differential section 10 by setting the exhaust differential section 10 excluding the small hole 8 through which the charged particle beam 4 passes among the openings connected to the differential section 10 as a gap between two opposed planes. The portion may be provided on at least one of the two planes, for example, on at least one of the two planes of the differential section 10 formed by the gap between the partition wall 5 and the fin 6.

In the above (4) or (5),
Of the openings connected to the differential section 10, the exhaust differential section 10 excluding the small holes 8 through which the charged particle beam 4 passes is a gap between two opposing planes, and is provided at a different position from the two planes. A sealing portion for closing the opening connected to the differential portion 10 may be provided, whereby the differential portion 10 can be designed independently of the sealing mechanism, and any differential pumping characteristics can be obtained.

In the above (5), the differential part 10 of the exhaust, excluding the small hole 8 through which the charged particle beam 4 passes, of the opening connected to the differential part 10 is moved between two opposed coaxial cylindrical surfaces. And a sealing portion for sealing the opening connected to the differential portion 10 may be provided at a portion different from the two cylindrical surfaces. In this case, the lens barrel chamber 2 is a rotatable rotating inner cylinder.

When the rotary lens barrel 3 is used as in the above (5), the opening connected to the exhaust differential section 10 is only the small hole 8 through which the charged particle beam 4 passes. The gap between the two cylindrical surfaces is sealed by magnetic fluid, O
The sealing may be performed by rotary vacuum sealing using either sealing with a ring or Wilson sealing.

In the case of sealing by rotary vacuum sealing, one end of the rotary vacuum seal may be opened to the high vacuum side of the lens barrel chamber 2 or the charged particle source chamber. Accordingly, since the vacuum pump is attached to the fixed outer cylinder, handling of the vacuum pump and its wiring becomes easy.

In the case of sealing by rotary vacuum sealing, one end of the rotary vacuum seal may be opened to the atmosphere side, so that the high vacuum side is low only through the small holes 8. Since it is connected to the vacuum side, the released gas and the like from the magnetic fluid do not flow into the high vacuum side, and a high vacuum can be realized by a vacuum pump having a small capacity.

[0025]

Embodiments of the present invention will now be described with reference to FIGS. 2 to 13. First, referring to FIGS. 2 to 4, a first embodiment of the present invention will be described. An embodiment will be described. 2 (a) and 2 (b). FIG. 2 (a) is a schematic cross-sectional view near the boundary between the sample chamber and the column chamber of the charged particle beam device during observation according to the first embodiment of the present invention. FIG. 2B is a top view of the charged particle beam apparatus at that time. The charged particle beam apparatus according to the first embodiment is a scanning electron microscope (SEM), in which an outer cylinder 11 forming an outer wall of a chamber is divided by a partition wall 12 having a race-track-type opening 13 and is divided into lower parts. Is the sample chamber 14, and the upper part is the lens barrel chamber 15.

A lens barrel 17 having a race track type fin 16 at its lower end is inserted into the opening 13 so as to be movable in the longitudinal direction of the opening 13, and a plurality of vent holes 18 are formed in the side wall of the lens barrel 17. And an electron beam 2 at the bottom.
A small hole 19 is provided to pass through, and a fin 16 is provided with an O-ring 20 in the shape of a race track. Note that an electrostatic lens (not shown) is provided inside the lens barrel 17, and an electron gun is provided above the lens barrel 17.

On the other hand, a rotating stage 23 on which a sample 24 such as an 8-inch (２４20 cm) Si wafer is mounted is disposed on the sample chamber 14 side. It is rotatable around the axis. Further, the sample chamber 14 is provided with a small hole sealing mechanism 21 having an O-ring 22 at an upper end, and seals a small hole 19 provided at the bottom of the lens barrel 17 at the time of sample replacement, as described later. Things.

In the charged particle beam apparatus according to the first embodiment, the differential portion of the exhaust
9 and a differential portion 2 comprising a gap between the partition 12 and the fin 16
8, while rotating the sample 24 around the rotation axis 25, and setting the distance between the partition 12 and the fin 16 to 0.1 mm.
The electron beam 27 is irradiated by linearly moving the lens barrel 17 in the long axis direction of the opening 13 so that the small hole 19 passes through the center of the rotation axis 25 while maintaining the following. Is detected by a scintillator and a photomultiplier tube (both not shown).

FIG. 3 is an exploded perspective view showing a main part of such a charged particle beam apparatus. For example, a partition wall 12 has a length l =
160 mm, width w = 45 mm, radius r = 22.5 at both ends
A race track-shaped opening 13 having a semicircle of mm is provided. The fin 16 integrated with the lens barrel 17 has a thickness t = 4 mm, a length L = 190 mm, a width W = 75 mm,
Both ends are racetrack-shaped plates having a semicircular shape with a radius R of 37.5 mm, and the center of the lens barrel 17 has a diameter φ of 2 m.
m small holes 19 are provided.

As an evacuation mechanism of this charged particle beam apparatus, for example, the sample chamber 14 is evacuated at a rate of 250 liters / liter.
Each second, the lens barrel chamber 15 is constituted by an evacuation speed of 60 l / sec, and a vacuum evacuation system mainly composed of independent turbo molecular pumps. By these evacuation systems, the sample chamber 14 is kept at 1 × 10 ⁻³ Pa or less during observation, that is, 1 × 10 ⁻³ Pa.
At a vacuum higher than × 10 ⁻³ Pa, the lens barrel chamber 15 is 1 ×
It is evacuated to a vacuum of 10 ⁻⁵ Pa or less, that is, higher than 1 × 10 ⁻⁵ Pa.

When evacuating using such a vacuum evacuation system, the conductance (20 ° C. air) of the small hole 19 provided at the bottom of the lens barrel 17 is 0.359 × 116 m / s × 3.14 × (1 mm ) ² ≒
1.3 × 10 ⁻⁴ m ³ / s. On the other hand, the conductance (at 20 ° C. air) of the gap between the partition 12 and the fin 16 is 0.1 mm when the gap between the partition 12 and the fin 16 is 0.1 mm. 3/8 × ln (15 mm / 0.1 mm) × 309 m / s
× 418mm × (0.1mm) ² /15mm≒1.6×
10 ⁻⁴ m ³ / s.

When the degree of vacuum in the sample chamber 14 is 1 × 10 ⁻³ Pa or less, the degree of vacuum in the lens barrel chamber 15 is set to 1 × 10 ⁻⁵ Pa or less. Seen differential part 2
The maximum gas release rate of 8,29 is (1.3 × 10 ⁻⁴ m ³ /s+1.6×10 ⁻⁴ m ³ / s)
× (1 × 10 ⁻³ Pa−1 × 10 ⁻⁵ Pa) ≒ 2.9 × 10
^-7 Pa · m ³ / s, which is necessary for exhausting this
The pumping speed of the vacuum pump on the fifth side is 2.9 × 10 ⁻⁷ Pa · m ³ / s ÷ 1 × 10 ⁻⁵ Pa = 29
Although liter / s is required, it can be kept within the exhaust speed of 60 liter / s of the turbo molecular pump for exhausting the lens barrel chamber 15.

4 (a) and 4 (b) FIG. 4 (a) schematically shows the vicinity of the boundary between the sample chamber and the lens barrel chamber of the charged particle beam apparatus at the time of sample replacement according to the first embodiment of the present invention. FIG. 4B is a cross-sectional view, and FIG. 4B is a top view of the charged particle beam device at that time. At the time of sample exchange, the lens barrel 17 is moved to the left in the long axis direction of the opening 13, and the fin 16 is pressed against the partition wall 12 at that position, and the opening 13 is sealed together with the differential portion 28 by the O-ring 20. By pressing the stop mechanism 21 against the bottom of the lens barrel 17, the small hole 19 forming the differential portion 29 is sealed by the O-ring 22 provided at the upper end of the small hole sealing mechanism 21.

After the opening 13 and the small hole 19 are sealed in this way, the sample chamber 14 is opened to the atmosphere and the sample 24 is exchanged.
The sample chamber 14 is evacuated again, and when the degree of vacuum in the sample chamber 14 reaches 1 × 10 ⁻³ Pa, the opening 13 and the small hole 1
9 is released, the differential portions 28 and 29 are operated, and the observation of the sample 24 is resumed.

As described above, in the first embodiment of the present invention, when irradiating the entire surface of the sample 24 with the electron beam 27, the rotational movement of the sample 24 and the movement of the lens barrel 17 are performed without using the XY stage. Since it is used in combination with linear motion,
The sample chamber 14 can be reduced in size. That is, in order to arbitrarily set the electron beam 27, and hence the relative position between the lens barrel 17 and the sample 24, at least two axes of freedom are required. It is very difficult to realize differential pumping, but the movement of the lens barrel 17 is limited to one axis direction, and the other axis is the sample 24.
By moving the sample 24 as a rotational motion, the sample chamber 14 can be reduced in size while realizing differential evacuation.

In the first embodiment, the lens barrel 17 is moved to a position outside the sample 24,
Since the opening 13 and the small hole 19 are sealed at that position, the sample chamber 14 can be opened to the atmosphere while the lens barrel chamber 15 is kept at a high vacuum. Therefore, the sample can be exchanged without providing a load lock chamber as in the related art, so that the size of the entire apparatus can be reduced in combination with the downsizing of the sample chamber 14, and the installation area can be reduced.

Next, a charged particle beam apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
The charged particle beam device according to the second embodiment is the same as the first embodiment except for the configuration of the lens barrel and the fins. Therefore, the description of the common parts is omitted. I do. FIGS. 5A and 6A are schematic cross-sectional views showing the vicinity of the boundary between the sample chamber and the lens-barrel chamber of the charged particle beam apparatus at the time of observation and sample exchange according to the second embodiment of the present invention, respectively. FIG. 5B and FIG. 6B are top views of the charged particle beam device at that time, respectively.

Referring to FIGS. 5A and 5B, in the second embodiment, the lens barrel 31 is provided with an upper member composed of a side wall provided with the vent hole 18 and a fin 32 of a race track shape, It is provided with a small hole 19 through which the electron beam 27 passes, and is divided into a lower member composed of a fin 30 having a racetrack shape asymmetric with respect to the small hole 19 and a cylindrical portion inserted into the upper member. That is, the fin 32 constituting the differential portion 33 and the fin 30 for closing the opening 13 connected to the differential portion 33 are separated.

Referring to FIGS. 6A and 6B, the lens barrel 3 is also used when the sample is exchanged in the second embodiment.
1 is moved to the left in the long axis direction of the opening 13, the fin 30 is pressed against the partition wall 12 at that position, the opening 13 is sealed by the O-ring 20, and the small hole sealing mechanism 21 is moved to the lens barrel 31.
The small hole 19 constituting the differential portion 29 is sealed by the O-ring 22 provided at the upper end of the small hole sealing mechanism 21 by pressing against the bottom of the small hole.

In the second embodiment, since the fins 32 forming the differential portion 33 and the fins 30 sealing the differential portion 33 are separated, the O-ring 20 sealing the differential portion 33 is crushed. The spacing between the gap and the gap between the differential portion 33 can be set independently, whereby a larger pressure difference and more reliable vacuum sealing can be realized as compared with the first embodiment. it can.

Next, a charged particle beam apparatus according to a third embodiment of the present invention will be described with reference to FIGS.
In the charged particle beam apparatus according to the third embodiment, the configuration of the lens barrel and the fins is changed, the fin is provided with a rotation axis, and the movement of the lens barrel is rotated. Although the shape of the opening provided in the partition is made semicircular, the other configuration is the same as that of the above-described first embodiment, and the description of the common part is omitted. FIGS. 7A and 8A are schematic cross-sectional views near the boundary between the sample chamber and the lens barrel chamber of the charged particle beam apparatus at the time of observation and at the time of sample exchange, respectively, according to the third embodiment of the present invention. FIG. 7B and FIG. 8B are top views of the charged particle beam device at that time, respectively.

7 (a) and 7 (b) In the third embodiment, the shape of the fin 36 provided integrally with the bottom of the lens barrel 35 provided with the vent hole 18 is circular, and Rotation axis 3 in the center of the fin 36
7 is provided to rotate the lens barrel 35 and the fin 36 around the rotation axis 37. In addition, a semi-annular opening 34 is provided in the partition wall 12 so as to enable the rotational movement of the lens barrel 35. At the time of observation, the small holes 19 are rotated with the rotational movement of the lens barrel 35. It is necessary to pass through the center of the sample 24 and therefore the center of the rotation axis 25. The fin 36 has an O that seals the opening 34 and the penetrating portion of the rotating shaft 37.
A ring 38 is provided.

In the third embodiment, the sample 2
By combining the rotational movement of 4 and the rotational movement of the lens barrel 35, the entire surface of the sample 24 is irradiated with the electron beam 27 for observation. In this case, the differential section is
As in the first embodiment, the partition 12 and the fin 3
6 and a differential portion 29 formed by the small holes 19.

Referring to FIGS. 8A and 8B, when the sample is exchanged in the third embodiment, the lens barrel 3
8 is rotated counterclockwise around the rotation axis 37 in FIG. 8B, and the fins 36 are pressed against the partition wall 12,
The opening 34 and the through portion of the rotating shaft 37 are sealed together with the differential portion 28 by the O-ring 38, and the small hole sealing mechanism 21 is provided on the upper end of the small hole sealing mechanism 21 by pressing the small hole sealing mechanism 21 against the bottom of the lens barrel 35. The small hole 19 forming the differential portion 29 is sealed by the O-ring 22.

In the third embodiment, the lens barrel 3
Since the movement of the fin 3 and the fin 36 is a rotational movement,
Since the space for the movement of the sample chamber 6 is not required, the size of the sample chamber 14 can be further reduced.

Next, a charged particle beam apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS.
FIGS. 9A and 10A show the fourth embodiment of the present invention, respectively.
10A and 10B are schematic cross-sectional views of the vicinity of the boundary between the sample chamber and the lens barrel chamber of the charged particle beam apparatus at the time of observation and at the time of sample replacement in the embodiment of FIG. FIG. 3 is a top view of the charged particle beam device at the time. 9 (a) and 9 (b). The charged particle beam apparatus according to the fourth embodiment is also a scanning electron microscope (SEM), and includes a fixed outer cylinder 41 and a rotating inner cylinder 42 which form the outer wall of the chamber. The rotating inner cylinder 42 is separated into a sample chamber 14 and a lens barrel chamber 15 by a bottom surface having the small holes 19. The lens barrel chamber 15 includes an electrostatic lens and an electron gun. The small lens barrel (not shown) is disposed so that the axis thereof coincides with the small hole 19.

In this case, a bearing mechanism 46 is provided on the outer wall surface of the rotary inner cylinder 42 so as to be rotatable while enabling differential exhaust, and the bearing mechanism 46 is held down by a holding member 47. Also, the rotating inner cylinder 42
A fin 43 for sealing is provided around the bottom surface of the O-ring 44 which seals between the rotating inner cylinder 42 and the inner wall surface of the fixed outer cylinder 41 during sample exchange. An O-ring 45 is provided to seal the opening 40 connected to the differential portion 48 formed by a gap with the outer wall surface of the rotary inner cylinder 42.

On the other hand, a rotary stage 23 for mounting a sample 24 such as an 8-inch (２４20 cm) Si wafer, for example, is arranged on the sample chamber 14 side, as in the first embodiment. The rotation stage 23 has a bearing mechanism 26
Thereby, it is rotatable around the rotation shaft 25. The sample chamber 14 is provided with a small hole sealing mechanism 21 provided with an O-ring 22 at the upper end. As will be described later, a small hole 1 provided at the bottom of the rotary inner cylinder 42 at the time of sample replacement is provided.
9 is sealed.

In the charged particle beam apparatus according to the fourth embodiment, the differential part of the exhaust
9 and a differential portion 48 formed by a gap between the inner wall surface of the fixed outer cylinder 41 and the outer wall surface of the rotating inner cylinder 42, and rotates the sample 24 around the rotation axis 25 and rotates the rotating inner cylinder 42. This causes the entire surface of the sample 24 to be irradiated with the electron beam 27, and reflected electrons from the sample 24 are detected by a scintillator and a photomultiplier tube (both not shown). Note that the position of the small hole 19 needs to be such that the small hole 19 passes through the center of the sample 24 and therefore the center of the rotating shaft 25 with the rotation of the rotary inner cylinder 42.

Referring to FIGS. 10A and 10B, when the sample is replaced in the fourth embodiment, the rotating inner cylinder 42 is rotated counterclockwise in FIG. A sealing fin 43 fixed around the bottom of the base 42 is pressed against the projection of the fixed outer cylinder 41 to seal the opening 40 connected to the differential part 48 with the O-ring 45, and the small hole sealing mechanism 21 is rotated inside. By pressing against the bottom of the cylinder 42, the small holes 19 forming the differential portion 29 by the O-ring 22 provided at the upper end of the small hole sealing mechanism 21.
Is sealed.

In the fourth embodiment, the portion constituting the differential section 48 and the opening 40 connected to the differential section 48 are formed.
Are separated, that is, the sealing fins 43 are separated, so that the gap between the crushing of the O-ring 45 for sealing the opening 40 connected to the differential portion 48 and the gap between the differential portions 48 can be set independently. In the fourth embodiment, the diameter of the sample chamber 14 and the length of the gap between the differential portions 48 can be set independently.
A larger pressure difference and a more reliable vacuum sealing can be realized without increasing the size of 4.

Next, a charged particle beam apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. FIGS. 11A and 12A are schematic cross-sectional views showing the vicinity of the boundary between the sample chamber and the lens barrel chamber of the charged particle beam apparatus at the time of observation and sample exchange according to the fifth embodiment of the present invention, respectively. FIG. 11B and FIG. 12B are top views of the charged particle beam device at that time, respectively. 11 (a) and 11 (b) The charged particle beam apparatus according to the fifth embodiment is also a scanning electron microscope (SEM), and includes a sample chamber outer wall 51 and a sample chamber outer wall constituting the outer wall of the sample chamber 14. The sample chamber 14 and the lens barrel are constituted by a fixed outer cylinder 52 having the same diameter as that of the sample chamber 51 and integrally fixed via an O-ring 53, and a rotating inner cylinder 54. A small lens barrel (not shown) having an electrostatic lens and an electron gun is arranged in the lens barrel chamber 15 so that the axis thereof coincides with the small hole 19. Will be done.

In this case, a bearing mechanism 55 is provided on the outer wall surface of the rotary inner cylinder 54 so as to be rotatable. Above the bearing mechanism 55, a magnetic fluid holding member 56 is provided via an O-ring 58. The magnetic fluid holding member 56 is fixed to the inner wall surface of the fixed outer cylinder 52.
A magnetic fluid 57 is provided on the surface facing the, and the magnetic fluid 57 performs rotary vacuum sealing.

On the other hand, on the sample chamber 14 side, similarly to the first embodiment, a rotary stage 23 for mounting a sample 24 such as an 8-inch (等 20 cm) Si wafer is arranged. The rotation stage 23 has a bearing mechanism 26
Thereby, it is rotatable around the rotation shaft 25. The sample chamber 14 is provided with a small hole sealing mechanism 21 having an O-ring 22 at the upper end. As will be described later, a small hole 1 provided at the bottom of the rotating inner cylinder 54 at the time of sample replacement is provided.
9 is sealed.

In the charged particle beam apparatus according to the fifth embodiment, the differential part of the exhaust
The electron beam 27 is irradiated onto the entire surface of the sample 24 by rotating the sample 24 around the rotation axis 25 and rotating the rotating inner cylinder 54 while exhausting the gas through the differential unit 29. Sample 24
Backscattered electrons are detected by a scintillator and a photomultiplier tube (both not shown). The position of the small hole 19 is determined by the rotation of the rotary inner cylinder 54.
It is necessary to pass through the center of the sample 24 and therefore the center of the rotation axis 25.

Referring to FIGS. 12 (a) and 12 (b), when the sample is replaced in the fifth embodiment, the rotating inner cylinder 54 is rotated counterclockwise in FIG. By pressing the stop mechanism 21 against the bottom of the rotary inner cylinder 54, the O
The small holes 19 forming the differential portion 29 are sealed by the ring 22.

In the fifth embodiment, since no differential portion is provided other than the differential portion 29, there is no need to provide a sealing mechanism other than the small hole sealing mechanism 21, and the rotary inner cylinder 54 Suffices to make only a rotary motion, so that the motion mechanism is simplified.

Next, two types of exhaust mechanisms of the charged particle beam apparatus according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 13A shows a type in which one end of a rotary sealing mechanism is opened to the atmosphere side. In this case, exhaust of the lens barrel chamber 15 is performed by a vacuum pump attached to a rotary inner cylinder 54 (see FIG. 13A). Not shown)
Air is exhausted in the direction of the arrow in the figure. In the drawings, reference numeral 59 denotes an O-ring that seals the upper end side of the magnetic fluid holding member 56, reference numeral 60 denotes a bearing mechanism provided on the upper side of the rotary inner cylinder 54, and reference numeral 61 denotes a bearing mechanism. And a holding member for holding the bearing mechanism 60.

In this case, the high vacuum side is connected to the low vacuum side only through the small hole through which the charged particle beam passes, so that the gas released from the magnetic fluid 57 does not flow into the high vacuum side, and The required degree of vacuum can be realized with a vacuum pump having a small capacity.

FIG. 13B shows a type in which one end of the rotary sealing mechanism is opened to the high vacuum side. In this case, the exhaust of the lens barrel chamber 15 is attached to the fixed outer cylinder 62. The air is evacuated by a vacuum pump (not shown) in the direction of the arrow in the figure. In the figure,
Reference numeral 59 denotes O for sealing the upper end side of the magnetic fluid holding member 56.
Reference numeral 64 denotes a bearing mechanism provided on the upper side of the rotating inner cylinder 63. Reference numeral 65 denotes a ring.
It is a holding member for holding the bearing mechanism 64.

In this case, the vacuum pump is
The vacuum pump and its wiring are easy to handle because they are attached to the vacuum pump, and the relationship between the high vacuum side and the low vacuum side is similar to that of the first to fourth embodiments.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above embodiments, and various modifications are possible. For example, in the description of each of the above-described embodiments, a scanning electron microscope (SEM) has been described as a charged particle beam apparatus. However, the charged particle beam apparatus is not limited to the SEM, and is not limited to the SEM. SIMS), and its application is not limited to simply observing the surface of a sample, but is also applicable to a charged particle beam apparatus that processes the surface of a sample with a charged particle beam. Things.

In the description of the first to third embodiments, the O-ring for sealing the differential portion is provided on the fin side, but may be provided on the partition side. Alternatively, the O-rings may be provided on both sides, and the O-rings may be provided twice in order to further ensure vacuum sealing.

In the description of the fifth embodiment, the space between the fixed outer cylinder 52 and the rotating inner cylinder 54 is rotary-vacuum sealed using the magnetic fluid 57. The means for performing vacuum sealing is not limited to the magnetic fluid 57, but may be sealing with an O-ring or using Wilson sealing.

[0065]

According to the present invention, the sample is moved in one direction of freedom and the lens barrel or charged particle source is moved in another direction of freedom, so that the XY stage is not used. Since it becomes possible to irradiate the beam on the entire surface of the sample and the space for movement is small,
Since the size of the sample chamber can be reduced, the cost for manufacturing the apparatus can be reduced and restrictions on introducing the apparatus can be reduced.

Further, since a mechanism for sealing the opening connected to the differential pumping section is provided, the sample chamber can be exposed to the atmosphere while the lens barrel chamber is kept at a high vacuum, thereby making the load lock chamber open. Since a semiconductor sample or the like can be exchanged without providing the charged particle beam device, it greatly contributes to the realization of a charged particle beam device that can be more easily used.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a state during observation of the charged particle beam device according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a main part of the charged particle beam device according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a state of the charged particle beam device according to the first embodiment of the present invention when a sample is exchanged.

FIG. 5 is an explanatory diagram of a state at the time of observation of a charged particle beam device according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a state of a charged particle beam device according to a second embodiment of the present invention when a sample is exchanged.

FIG. 7 is an explanatory diagram of a state during observation of the charged particle beam device according to the third embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating a state of a charged particle beam device according to a third embodiment of the present invention when a sample is exchanged.

FIG. 9 is an explanatory diagram of a state at the time of observation of a charged particle beam device according to a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram illustrating a state of a charged particle beam device according to a fourth embodiment of the present invention when a sample is exchanged.

FIG. 11 is an explanatory diagram of a state at the time of observation of a charged particle beam device according to a fifth embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating a state of a charged particle beam device according to a fifth embodiment of the present invention when a sample is exchanged.

FIG. 13 is an explanatory diagram of an exhaust mechanism of a charged particle beam device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sample chamber 2 lens barrel chamber 3 lens barrel 4 charged particle beam 5 partition 6 fin 7 sample 8 small hole 9 sealing mechanism 10 differential section 11 outer cylinder 12 partition 13 opening 14 sample chamber 15 lens barrel 16 fin 17 lens barrel Reference Signs List 18 Vent hole 19 Small hole 20 O-ring 21 Small hole sealing mechanism 22 O-ring 23 Rotary stage 24 Sample 25 Rotation axis 26 Bearing mechanism 27 Electron beam 28 Differential part 29 Differential part 30 Fin 31 Lens barrel 32 Fin 33 Difference Moving part 34 Opening 35 Lens barrel 36 Fin 37 Rotating shaft 38 O-ring 40 Opening 41 Fixed outer cylinder 42 Rotating inner cylinder 43 Sealing fin 44 O-ring 45 O-ring 46 Bearing mechanism 47 Pressing member 48 Differential part 51 Sample chamber outer wall 52 Fixed outer cylinder 53 O-ring 54 Rotating inner cylinder 55 Bearing mechanism 56 Magnetic fluid holding member 57 Magnetic fluid 8 O-ring 59 O-ring 60 bearing mechanism 61 pressing member 62 fixed outer cylinder 63 rotates in the cylinder 64 a bearing mechanism 65 pressing member

Claims (5)

[Claims] 1. A charged particle beam apparatus for irradiating a charged particle beam to an arbitrary position of a sample while differentially evacuating a sample chamber and a lens barrel chamber or a charged particle source chamber, wherein the charged particle source, the lens barrel, A charged particle beam apparatus, wherein the sample is moved in a direction of a first degree of freedom and the sample is moved in a direction of a degree of freedom different from the first degree of freedom. 2. The apparatus according to claim 1, further comprising a differential portion sealing mechanism for sealing at least an opening connected to the differential portion of the exhaust gas, wherein the sample can be exchanged without providing a load lock chamber. 2. The charged particle beam device according to 1. 3. The charged particle beam apparatus according to claim 1, wherein the movement of the sample is a rotational movement about a normal line of an irradiation surface of the charged particle beam as a rotation axis. 4. The method according to claim 1, wherein the movement of the lens barrel and a member integrated with the lens barrel is linear movement, and the small hole that forms an opening connected to the differential part and through which a charged particle beam passes is formed by the sample. 4. The charged particle beam device according to claim 3, wherein the charged particle beam device passes through a rotation axis of the charged particle beam. 5. The movement of the lens barrel and a member integrated with the lens barrel is a second rotational movement about a normal to an irradiation surface of the charged particle beam as a rotation axis, and the differential section 4. The charged particle beam apparatus according to claim 3, wherein a small hole which forms an opening leading to the sample and through which the charged particle beam passes passes through the rotation axis of the sample.