JP2000149846A - Charged particle beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged particle beam device in which the inside of a sample chamber can be baked without any deterioration in accuracy of a stage and a sample can be prevented from being contaminated due to dust. SOLUTION: In a high vacuum container for arranging a sample therein, only a part of an X-stage 12 is arranged on the inside while an X-stage driving means 14, a Y-stage 11, a Y-stage driving means 13, a tilting stage 10 and a tilting stage driving means, which are gas/dust generating sources, are arranged on the outside, so that contamination of the sample is greatly reduced in comparison with a conventional one. As the stage driving means and the stages arranged on the outside are not heated even when a heat wire 4 is heated for baking the high vacuum container, deterioration in accuracy, which is conventionally caused in the stage because of baking, can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a charged particle beam apparatus such as a scanning electron microscope and an Auger electron spectrometer.

[0002]

2. Description of the Related Art In a scanning electron microscope or an Auger electron spectrometer, a sample is placed on an XY stage.
The XY stage is placed on a tilt stage for tilting the sample. Then, the sample is moved or tilted in the XY directions according to the purpose.

[0003] These stages are required to have positional accuracy, reproducibility, and the like, and current stages are processed with high accuracy and assembled with high accuracy to meet these requirements.

[0004]

However, although the current stage meets the above-mentioned requirements, its structure is rather complicated. For this reason, gas and dust are likely to come out, causing contamination of the sample.

[0005] As a method of reducing the generation of gas, baking to bake the sample chamber at a high temperature is the most common. However, this baking causes distortions inherent in the components of the stage to appear, thereby deteriorating the accuracy of the stage. Inviting.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent a sample chamber from being baked without deteriorating the accuracy of the stage and to prevent contamination of the sample by dust. It is to provide a charged particle beam device that can be used.

[0007]

Means for Solving the Problems A charged particle beam apparatus according to the present invention that achieves this object includes a low vacuum container, a high vacuum container disposed in the low vacuum container, and a device for introducing charged particles. A charged particle optical system connected to the high vacuum container, a sample stage for mounting a sample in the high vacuum container, a sample stage driving unit provided in the low vacuum container, A connecting member for connecting the sample stage in the vacuum vessel, and a pressure maintaining for maintaining a pressure difference between the high vacuum chamber and the low vacuum chamber regardless of the movement of the connecting means accompanying the driving by the stage driving means. Means.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a scanning electron microscope shown as an example of the present invention.

In FIG. 1, reference numeral 1 denotes a low vacuum container, and an exhaust device 2 is attached to the low vacuum container 1.

A sample container 3 is arranged inside the low vacuum container 1. The sample container 3 has a cylindrical sample container 3a.
And a flange portion 3b provided at one end thereof;
The sample introduction pipe 3c is provided at the other end of a and penetrates the side wall of the low vacuum vessel 1 and is fixed to the side wall.

A heater wire 4 is provided on the outer periphery of the sample container 3a.
Is wound, and the heating of the heater wire 4 is controlled by the heating means 5. An electron optical system 6 is attached to the sample storage section 3a, and the electron optical system 6 includes an electron gun, a focusing lens, an electron beam deflector, and the like. The electron optical system 6 penetrates through the low vacuum vessel 1.

Reference numeral 7 denotes a sample exchange mechanism.
Is attached via a vacuum valve 8 to a sample introduction pipe 3c penetrating the side wall of the low vacuum vessel 1. Further, an exhaust device 9 is attached to the sample introduction tube 3c.

Reference numeral 10 denotes a tilt stage attached to the side wall of the low vacuum vessel 1.
It is rotatable about an axis S parallel to the axis. The tilt stage 10 is driven by driving means provided in the low vacuum vessel 1.

A Y stage 11 is provided on the tilt stage 10.
The X stage 12 as a connecting member is formed on the Y stage 11. The Y stage 11 is moved in the Y axis direction by the Y stage
The stage 12 is moved in the X-axis direction by the X-stage driving means 14.

A rotary moving plate 15 is fixed to the Y stage 11, and the rotary moving plate 15 has a cylindrical stage penetrating portion 15a through which the X stage 12 passes.
And a brim portion 15b facing the brim portion 3b of the sample container.
It is composed of The sample container 3 and the rotary moving plate 1
5 constitutes a high vacuum container.
The stage 12 is penetrating. Collar 3b of sample container 3
A slight gap is provided between the flange 15b of the rotary moving plate 15 and the orifice formed in this portion. The rotary moving plate 15 is moved in the Y-axis direction together with the X stage 12 by the movement of the Y stage 11. However, even if the X stage 11 moves in the X axis direction, it is fixed to the Y stage 11 and does not move in the X axis direction, so that the gap is always kept constant.

Reference numeral 16 denotes a shield plate, which is provided so that the electron beam is not affected by a magnetic field generated by stage driving means or the like. Reference numeral 17 denotes a sample stage mounted on the X stage 12, on which a sample is placed.
The stage 12 is connected to stage driving means. FIG. 2 is a perspective view of the vicinity of the rotary moving plate 15.

The configuration of the apparatus shown in FIG. 1 has been described above. In the apparatus shown in FIG. 1, only a part of the X stage 12 is arranged inside the sample container 3 in which the sample is arranged, and gas and dust are removed. X stage driving means 14, Y stage 11, Y stage driving means 13, tilt stage 1
Since the zero and tilt stage driving means are disposed outside, the contamination of the sample is significantly reduced as compared with the prior art.

Further, even if the heater wire 4 is heated and the high vacuum vessel is baked, the stage driving means and the stage disposed outside the heater are not heated. Can be prevented.

In the configuration shown in FIG. 1, since the tilt stage and the like need not be disposed in the high vacuum vessel, the volume of the high vacuum vessel can be reduced. In addition, since the high vacuum container is in the evacuated low vacuum container 1, there is no need to withstand the atmospheric pressure, and the sample container 3 can be made thin with a material such as SUS or aluminum which emits little gas. For this reason, if a high vacuum container is made in this way, the required power during baking is much smaller than when baking a thick chamber that can withstand atmospheric pressure, and the temperature of the high vacuum container can be raised.

Although the apparatus shown in FIG. 1 has been described above, the present invention is not limited to this apparatus, and various other modifications are possible. For example, as shown in FIG. 3, the shield plate 18
, The gap is divided into two, and the exhaust device 19 is further provided, so that the low vacuum chamber between the high vacuum vessel and the low vacuum vessel 1 in FIG. 1 can be further divided into a low vacuum chamber and a medium vacuum chamber. In addition to having a magnetic shielding effect, it is possible to further restrict gas entering the high vacuum vessel.

[Brief description of the drawings]

FIG. 1 is a schematic view of a scanning electron microscope shown as an example of the present invention.

FIG. 2 is a perspective view of the vicinity of a rotary moving plate 15 of FIG.

FIG. 3 is a schematic view of a scanning electron microscope shown as an example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Low vacuum container, 2 ... Exhaust device, 3 ... Sample container, 3a ...
Sample storage section, 3b collar section, 3c sample introduction tube, 4 heater wire, 5 heating means, 6 electron optics, 7 sample exchange mechanism, 8 vacuum valve, 9 exhaust device, 10 tilt Stage, 11 ... Y stage, 12 ... X stage, 13 ... Y
Stage driving means, 14 ... X stage driving means, 15 ...
Rotational moving plate, 15a: Stage penetrating portion, 15b: flange portion, 16: shield plate, 17: sample stage, 18: shield plate, 19: exhaust device

Claims (1)

[Claims] 1. A low vacuum container, a high vacuum container disposed in the low vacuum container, a charged particle optical system connected to the high vacuum container for introducing charged particles, A sample stage for mounting a sample, sample stage driving means provided in the low vacuum vessel, a connecting member for connecting the sample stage driving means to the sample stage in the high vacuum vessel, and the stage driving means And a pressure maintaining means for maintaining a pressure difference between the high vacuum chamber and the low vacuum chamber irrespective of the movement of the connecting means accompanying the driving of the charged particle beam apparatus.