JPH0369138B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a device for holding a sample such as a semiconductor substrate wafer (hereinafter referred to as a wafer), and particularly to a device suitable for holding a sample such as a wafer in a vacuum. Related to a sample holding device.

[Background of the invention]

When observing a sample such as a wafer using a scanning electron microscope or an electron beam lithography device, or performing electron beam lithography on the surface of a sample such as a wafer, the sample such as a wafer in the atmosphere is placed on a sample stage and placed under vacuum. A method of observing or drawing a sample such as a wafer under vacuum is adopted.

For example, when holding a wafer, a conventional sample holding device of this type has a plate fixed to the sample holding table, and a part of the circumference of the wafer is cut out in a straight line using vacuum tweezers or the like. The upper surface of the outer periphery of the wafer is pressed with a spring or the like against a support that supports the outer periphery of the wafer and is fixed to the sample holding table. The wafer was held by pressing.

However, in the conventional sample holding device described above, since the setting to hold the sample is done manually using tweezers, etc., there is a high probability that dust will adhere to the device, and the edge or top of the wafer is held by a spring. The wafer gets scratched because it is pressed down with etc. Furthermore, it has the disadvantage that the wafer cannot be positioned accurately.

[Purpose of the invention]

An object of the present invention is to provide a sample holding device that can accurately position a sample without damaging the sample.

[Summary of the invention]

The present invention provides a sample holding device that holds a sample such as a wafer in a vacuum, including a support member fixed to a base, and a plurality of support members fixed to the base and holding the end face of the sample placed on the support member. a holding member; a plurality of holding members that hold the end surface of the sample placed on the supporting member;
The displacing means has a holder at its tip for holding the end face of the sample placed on the support member together with the holding member, and is displaced by changes in surrounding pressure, and the displacement means changes from atmospheric pressure to vacuum pressure. The holder at the tip is displaced to a position where it presses against the end surface of the sample when the sample changes to .

[Embodiments of the invention]

Embodiments of the present invention will be described based on the drawings. FIG. 1 shows the configuration of an embodiment of a sample holding device according to the present invention, and in the figure, 1 is a base, and a wafer 4 as a sample is placed on the base 1. A support member 3 is fixedly provided, and a wafer 4
A holding member 2 that holds the end face of the holding member 2 is fixedly provided.

Further, a displacement means 6 (metal bellows in this embodiment) having a holder 7 at its tip for holding the end face of the wafer 4 placed on the support member 3 together with the holding member 2 is fixed to the base 1. There is. metal bellows 6
Gas or liquid is sealed inside the metal bellows 6, and the holding body 7
Displace. Furthermore, 5 is a guide for regulating the direction of movement of the holder 7 when the metal bellows 6 is displaced due to a change in ambient pressure.

The operation of the sample holding device having the above configuration will be explained with reference to FIGS. 2 and 3. FIG. 2 shows the state before operation, and FIG. 3 shows the state after operation.

When the surrounding pressure is atmospheric pressure, the metal bellows 6 is in the state shown in FIG. The wafer is moved forward while sliding and continues to be displaced in the elongation direction until the orientation flat part of the wafer 4 contacts the holding member 2 and is held by the three holding members 2 and the holder 7. 4 (Fig. 3).

In the experimental results of this example, a maximum deviation of 5 microns at the center of a 4-inch wafer and a deviation of 15 microns at the edge of the wafer was observed. The eccentricity of the holding member 2 and the holding body 7 used at this time was 1 micron at most.

According to this embodiment, as described above, the following features and effects are achieved in the vacuum chamber.

(1) In a vacuum chamber, the above-mentioned holding device can automatically hold a wafer only by changing the pressure in the vacuum chamber.

(2) In the above-mentioned item 1, since the pressure decreases gradually, it is possible to statically and dynamically hold the wafer at the wafer holding position.

(3) The holding force for holding the wafer is that the pressure inside the vacuum chamber changes repeatedly from atmospheric pressure to a certain arbitrary pressure, so the holding force exerted by the holding member in the holding device on the wafer end surface is approximately Moreover, the above matters are very effective for reproducibility.

FIG. 4 shows another embodiment of the present invention, which differs from FIG. 1 in that an orientation flat pressing plate 8 is fixed directly to the metal bellows 6 on the orientation flat portion of the wafer 4. The holding member holds the wafer 4 at the wafer holding position by pressing the end of the orientation flat.

In this embodiment, since the number of holding members 2 can be reduced compared to the embodiment shown in FIG. 1, it is possible to reduce misalignment of the wafer caused by eccentricity of the holding members 2 in the holding device. is possible.

Furthermore, according to the embodiment, objects to be held are not limited to wafers, but also objects having a polygonal shape larger than a triangle can be reliably held in a vacuum by making the shape of the orientation flat press plate 8 correspond to the shape of the orientation flat press plate 8. It is possible to do so.

In FIG. 4, members given the same numbers as those in FIG. 1 indicate the same members, so a description thereof will be omitted here.

〔Effect of the invention〕

According to the present invention, it is possible to automatically and statically hold a sample such as a wafer in a vacuum chamber by changing the pressure in the chamber, and the reproducibility is good, so that the sample can be It is possible to accurately hold it in a predetermined position without having to do so.

In the above embodiments, the holding of the wafer has been described in detail, but this is not limited to just the wafer, but also applies to plates or blocks such as magnetic desks, audio desks, etc. Furthermore, although metal bellows are used as the displacement means in the embodiment, the present invention is not limited to these, and an elastic body such as rubber may be used.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the configuration of an embodiment of the sample holding device according to the present invention, FIGS. 2 and 3 are main parts of the front view of the sample holding device shown in FIG. 3 is a diagram showing the state before operation, FIG. 3 is a diagram showing the state after operation, and FIG. 4 is a plan view showing the configuration of another embodiment of the sample holding device according to the present invention. DESCRIPTION OF SYMBOLS 1...Base, 2...Holding member, 3...Supporting member, 4...
Wafer, 5... Guide, 6... Displacement means, 7... Holder, 8... Orientation press plate.

Claims (1)

[Claims] 1. A sample holding device that holds a sample such as a wafer in a vacuum, including a support member fixed to a base and an end face of the sample fixed to the base and placed on the support member. a plurality of holding members that hold the end face of the sample placed on the support member, and a holder for holding the end face of the sample placed on the support member together with the holding member at the tip. A sample holder comprising a means for displacing due to a change in surrounding pressure, and the displacing means displaces to a position where the holder at the tip presses against the end surface of the sample when the surrounding pressure changes from atmospheric pressure to vacuum pressure. Device. 2. The sample holding device according to claim 1, wherein the displacement means has a structure in which gas or liquid is sealed in an elastic body such as a metal bellows or rubber.