JPS63247359A - Ion beam mixing device - Google Patents

Abstract

PURPOSE:To obtain the titled device capable of preventing the mixing of foreign matter into an exhaust system pump owing to the falling of adhering metal from occurring, by constituting the device so that adhesion of vapor deposition material to the internal surface of a vacuum vessel is prevented by disposing a wall for restricting the scattering of an evaporated substance in the vicinity of an evaporation source. CONSTITUTION:A thin film is formed on the surface of a specimen attached to a specimen holder 3 by using ions 9 accelerated from an ion source 1 together with metallic molecules melted by means of an evaporation source 4. In the course of the above, the metallic molecules are radiated and distributed as shown in an equation and diffused onto the inner wall of a vacuum vessel 2. However, vapor deposition is not applied to the internal-surface part of the vessel 2 owing to the presence of a shutter 10. Accordingly, the vapor deposition material does not adhere to the part, in a position above an outlet 7, of the internal surface of the vessel 2, so that vapor deposition material is not mixed into the outlet 7. Moreover, the shutter 10 is rotatably constituted so that it can be located at an arbitrary rotation angle (theta) from the horizontal position 10a in a figure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion beam mixing device for modifying the surface of a material, and particularly to a vacuum vessel structure suitable for preventing the dispersion of deposits.

[Conventional technology]

When various metals are melted in a vacuum container, the melted metal molecules spread throughout the vacuum container and adhere to the inner wall of the vacuum container. When the metal attached to the inner wall increases to a certain thickness, it detaches from the wall surface and peels off.

On the other hand, the vacuum container is provided with an exhaust port.

If the separated vapor deposits enter this exhaust port, they will enter the exhaust system pump and cause problems with the pump. Conventional devices did not take this point into consideration.

Note that related devices of this type include, for example,
JP-A-61-99671 is mentioned.

[Problem that the invention seeks to solve]

When a metal object is dissolved and evaporated, the evaporation rate of molecules at the evaporation source is generally not uniform and has values that differ depending on the direction. This distribution differs depending on the shape of the evaporation source. When considering a disc-shaped evaporation source, as shown in FIG. 3(a), the metal molecules evaporated from the evaporation source 12 with a width of 2a have a distance h from the evaporation source 12 to the opposing plane 11, considering the opposing plane 11. , by the distance S on the plane measured from the intersection of the normal line passing through the center of the evaporation source 12 and the opposing plane, R8=□ 2πa2 (1) where, RI: the incidence frequency at the point of S=i Rn: Total evaporation rate S: Distance on the plane measured from the intersection of the normal line passing through the center of the evaporation source and the opposing plane a: Radius of the evaporation source h: Distance from the evaporation source to the opposing plane S = 0 point If the incidence frequency Rho is calculated from the above equation and the relationship between Rt/Rto is plotted on the vertical axis and S/h is plotted on the horizontal axis, a distribution as shown in FIG. 3(b) is shown.

FIG. 2 shows a cross-sectional view of the main parts of the ion mixing device. Ions accelerated from the ion source 1 are injected onto the surface of a sample attached to a sample holder 3. On the other hand, metal objects are E
It is melted and evaporated by the B gun 4. Then, ions and vapor deposition are performed simultaneously to form a thin film on the sample surface.

At this time, the evaporated metal molecules diffuse in a radial distribution as shown in equation (1). It also adheres to the inner wall surface 8 of the vacuum container 2. Once the attached metal object reaches a certain thickness, it will begin to peel off from the wall surface. On the other hand, an exhaust lower is disposed in the vacuum container for exhausting air, and if the peeled metal objects get mixed into this exhaust lower, they will enter the exhaust system pump. Exhaust system pumps are generally composed of a combination of TMP5 and RP6 or DP and RP in order to obtain an ultra-high vacuum, and if there is metal foreign matter, the pump 5
,6.

Conventional devices do not take this point into consideration, and an object of the present invention is to provide a device suitable for solving the above points.

[Means for solving problems]

The above object is achieved by arranging a wall near the deposition source to limit the diffusion of the evaporated material, that is, to limit the deposition on the inner wall of the vacuum vessel.

[Effect]

A shutter is placed near the deposition source.

Metal objects are melted using an EB gun or the like. Then, it evaporates, but when the sample is not being evaporated, the shutter is kept in a horizontal position. Then, the shutter is opened only when vapor deposition is performed on the sample. At this time, the shutter serves as an F1 barrier to prevent evaporated metal molecules from adhering to the wall surface of the vacuum vessel located around or above the exhaust port. That is, the evaporated molecules are deposited on the walls of the shutter.

By doing this, the deposits will not be sucked into the exhaust port or fall, and problems with the exhaust pump will not occur.

In addition, since the shutter has a structure that is easy to attach and detach, it becomes easy to remove, replace, and clean the shutter, which makes maintenance of the deposited material easier. Further, the shutter has a structure that can be rotated so as to be positioned at an arbitrary angle with respect to the direction in which the metal molecules are deposited. By providing such a vapor deposition protection wall,
Vapor deposits will not be sucked into or dropped into the exhaust port.

〔Example〕

An embodiment of the present invention will be shown below.

As shown in FIG. 1, the ion beam mixing device includes an ion source 1. Vacuum container 2. It is composed of a turbo molecular pump 5, a rotary pump 6, etc., which are exhaust system pumps. A sample holder 3 and an evaporation source 4 are arranged inside the vacuum container 2 .

The ions 9 accelerated from the ion source 1 and the metal molecules dissolved in the evaporation source 4 are used together to form a thin film on the surface of the sample attached to the sample holder 3.

Here, the metal molecules have a radiation distribution as shown in equation (1) and diffuse into the inner wall of the vacuum container 2. However, because of the shutter 10, vapor deposition is not performed on the inner wall surface 8 of the vacuum container 2, that is, the shutter 10 serves as a barrier. Therefore, since no deposits adhere to the inner surface 8 of the vacuum vessel 2 located above the exhaust lower, no deposits enter the exhaust lower.

The shutter 10 has a rotatable structure such that it can be positioned at an arbitrary rotation angle θ from a horizontal position 10a in the figure. This is because unless the sample size (S dimension in the figure) is large, the distance from the vapor deposition source 4 to the sample holder 3 is constant, so the aperture angle 0 of the shutter 10 also needs to be large.

In this way, the shutter 10
By arranging , it is possible to impose restrictions on vapor deposition on the inner wall surface 8 of the vacuum container 2 .

Therefore, it is possible to prevent deposits from peeling off from the inner wall surface 8 and falling into the exhaust lower, thereby making it possible to prevent foreign matter from entering the exhaust system pump.

That is, it is possible to prevent malfunctions of the exhaust system pump and provide a highly reliable ion beam mixing device.

C. Effects of the Invention] According to the present invention, it is possible to impose restrictions on the vapor deposition on the inner wall of the vacuum container, and it is possible to prevent foreign matter from entering the exhaust system pump due to the falling of these vapor-deposited metals.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention, FIG. 2 is a sectional view of a main part of a conventional device, and FIG. 3 is an explanatory diagram of a disc-shaped evaporation source. DESCRIPTION OF SYMBOLS 1... Ion source, 2... Vacuum container, 3... Sample holder, 4... EB gun, 5... TMP, 6...
RP, 7... Exhaust port, 8... Inner wall surface, 9... Ion beam, 10... Sha 11 Figure ¥2 Figure 3

Claims (1)

[Claims] 1. In an apparatus for modifying a surface using both an ion beam and vapor deposition, a wall surface is disposed near the vapor deposition source to limit the dispersion of evaporated materials, and to limit the diffusion of evaporated materials to the inner wall surface of the vacuum container. An ion beam mixing device characterized by preventing deposition of deposits. 2. The ion beam mixing device according to claim 1, further comprising a mechanism that rotates with respect to the evaporation direction.