JPS63282266A - Ion beam mixing device - Google Patents

Abstract

PURPOSE:To control the sputtering rate by an ion beam and to form a good- quality film by using the title device capable of controlling the incident angle of the ion beam to a cylindrical material and capable of forming a film by ion implantation or mixing. CONSTITUTION:In the ion beam mixing device (Fig. a) consisting of a vacuum vessel 2, an ion source 3 and an exhaust 4, the ion beam 9 drawn out from the ion source 3 is injected on the outer periphery of the cylindrical sample 7 with some divergent angle. In this case, a barrier 8a is arranged around the sample 7 rotating in direct connection to a sample holder 1. Accordingly, the incident angle of the beam to the sample 7 is determined by the opening width (l) of the barrier 8b as shown in Fig. b, and the incident angle theta is expressed by the equation. At this time, sputtering is carried out on the surface of the sample 7 simultaneously with the ion implantation. Consequently, if the angle to the sample surface is controlled to about theta <=30 deg.,a good quality film can be obtained without being relatively sputtered.

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. This invention relates to a reforming device.

[Conventional technology]

In surface modification by ion beam mixing, conventionally known as the zymating process, the target sample is placed at the cutting edge of a cutting tool, as shown in the photographs and illustrations in the proceedings of the 1st Ion Implantation Surface Treatment Symposium. In addition, surface modification is often performed on the outer peripheral surface of a hollow or solid cylinder of a relatively small article, whether it is a die, a roll, or the like. However, when the ion beam is incident on the cylindrical outer peripheral surface, the angle of incidence of the ion beam with respect to the irradiated surface of the sample 7 is in the range θ=0 to 90', as shown in FIG.

Note that the number of ion beams is 9, and the number of ion sources is 3.

On the other hand, when an ion beam is incident on a metal surface, not a little sputtering occurs on the metal surface along with the ion implantation. Furthermore, the sputtering rate is dependent on the incident angle of the beam. From the above point of view, conventional methods do not consider the sputtering rate depending on the incident angle of the beam.

[Problem that the invention seeks to solve]

The current value 1si extracted from the ion extraction port is expressed by considering that only monovalent ions are present in the plasma.

Here, Iss: space charge limited current d: extraction electrode gap ■=extraction voltage a: extraction port radius M: mass number of ions γ: relaxation coefficient of space charge limited current The accelerated ions 16 reach the sample surface 11.

That is, by applying a voltage between the plasma chamber 12 and the electrode 14 from the power supply 13, ions with a mass number M confined in the plasma chamber 12 are extracted from the extraction aperture 15, accelerated, and irradiated onto the sample surface 11. Ru. When the accelerated ions 16 collide with the sample surface 11, the secondary particles fly out from the surface of the sample 11 at high speed. There is sputtering of metal particles by particles. Not all of the primary particles are reflected by the surface atoms, but a percentage of the primary particles are injected into the metal, scattered by atoms in several layers from the surface, and a portion loses a large amount of energy. , may fly out, or in some cases remain in the metal or be implanted.

Ion beam mixing utilizes this implantation.

By the way, regarding the sputtering rate, Thompson
Thomps has n model and Sigmund model.
In the on model, ER: Rydberg energy (13,6
eV) EB: Surface binding energy ao: Bohr radius (0,53 people) N: Metal atomic density Ml, Zl: Mass number and atomic number of incident particles Mz, Zz:
The mass number and atomic number θ of the target particle are expressed by the angle of incidence, resulting in the curve (1) in FIG. 2(b).

In the 3igmund model uo: Sublimation energy Co: Coefficient related to metal target 5n(E): Inhibition cross section for substitution α (Mz/Mz): Expressed as energy conversion efficiency.

In the above equations (1) and (2), the normalized sputtering rate S(θ)/5(0) is plotted on the vertical axis, and the incident angle θ is plotted on the horizontal axis, as shown in Figure 2 (b). become.

The Thompson model represents curve (1), and Si
The gmund model represents curve (2).

By the way, it is experimentally known that the maximum angular dependence of the sputtering rate actually occurs when the beam incidence angle is between θ = 50 and 80, as shown by the point and line shown in Figure 2 (b). It is being

On the other hand, when the beam is incident on a rotating cylinder such as a roll, the incident angle of the beam is θ=0 to 90 as shown in Figure 3.
'', which means that sputtering is also being performed along with ion implantation.

Conventional apparatuses do not take into account the dependence of the beam incidence angle on sputtering, and this poses a problem as a film forming process for obtaining good film quality.

An object of the present invention is to place a beam barrier on the outer periphery of the sample in order to minimize the sputtering rate on the sample surface when the beam is incident on the cylindrical outer circumferential surface of a roll or cutting tool to modify the surface. An object of the present invention is to provide an ion beam mixing device that imposes a limit on the incident angle of the ion beam, performs surface modification, and obtains highly reliable film quality.

[Means for solving problems]

The above purpose is to place a barrier for the ion beam on the outer periphery of the cylindrical sample to reduce the width of the beam incident on the sample surface, that is, to reduce the angle of incidence of the beam on the cylindrical surface of the sample and impose restrictions. This is achieved by

[Operation] The sample, such as a roll, is mixed while being rotated in combination with ion implantation or vapor deposition.

A barrier is placed on the outer periphery of the sample, independent of the rotating sample, and has an opening with an arbitrary width relative to the beam irradiation surface. By varying the dimensions of the six apertures in which the beam is irradiated onto the sample surface only in the range of the aperture, it is possible to change the angle of incidence of the beam on the cylindrical sample surface.

As described above, by arranging the barrier around the outer periphery of the sample and limiting the incident angle of the beam, it becomes possible to perform injection or mixing with a reduced sputtering rate.

〔Example〕

An embodiment of the present invention will be described below.

The ion beam mixing device is comprised of a vacuum capacity 2, an ion source 3, and an exhaust device 4, as shown in FIG. 1(a).

The ion beam 9 extracted from the ion source 3 has a certain degree of divergence angle and enters the outer peripheral surface of the sample 7. The sample 7 is directly connected to the sample holder 1 and rotated by a rotation mechanism. Then, on the outer periphery of the rotating sample 7,
A barrier wall 8a is arranged. The barrier 8a is independent of the sample 7 and is fixed to the fixture 6 without being rotated. Therefore, the beam incidence angle to the sample 7 is (b
), it is determined by the opening width 2 of the barrier wall 8b, and the incident angle θ is expressed by .

At this time, sputtering occurs on the surface of the sample 7 at the same time as the ion implantation, as described above.

Moreover, the sputtering rate has dependence on the incident angle of the beam, as shown in FIG. 2(b).

As a result of studying this sputtering and the quality of the film formed, the present inventor found that when an ion beam is incident and mixed while rotating a cylindrical sample, the incident angle of the beam is θ≦30” with respect to the sample surface. It has been found that a film of good quality can be obtained with relatively little sputtering if controlled to a certain extent.

That is, when implanting or mixing ions while rotating the sample 7 of radius R as shown in FIG. 1(a),
As can be seen from the above equation (3), the opening width Q of the barrier wall 8b may be set such that Q≦R with respect to the radius R of the sample 7.

The arrangement of the EB gun, which is the evaporation source for the incidence of the ion beam 9, is as shown in FIGS. 1(a) and 1(b). (a) The figure shows an EB gun 5 directly below the beam entrance 10.
A is placed. In the figure (b), an opening 10a of a barrier 8b is provided at a position different from the beam entrance 10, and an EB gun 5b is placed directly below the opening 10a.

In either case, there are no particular problems when forming a film by mixing.

[Effects of the Invention] As explained above, according to the present invention, since ion implantation or mixing film formation is performed by imposing restrictions on the incident angle of the ion beam, restrictions are imposed on the sputtering rate by the ion beam. It becomes possible to obtain high-quality film formation, and a highly reliable ion beam processing machine can be provided.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main part of the present invention, Figure 2 (a) is a schematic diagram when ions are extracted, and Figure 2 (b) shows the sputtering rate normalized to the beam incidence angle. The diagram shown in FIG. 3 is a sectional view of a main part showing the incidence of an ion beam in a conventional apparatus. DESCRIPTION OF SYMBOLS 1... Sample holder, 2... Vacuum container, 3... Ion source, 4... Vacuum exhaust device, 6... Fixed metal, 7...
... Sample, 9... Ion beam, ... 11... Sample surface, 12... Plasma generation chamber, 13... Power supply, 1
4... Extraction electrode, 10th Q) 2r23 Mi (b) Angle (θ)

Claims (1)

[Scope of Claims] 1. In a device that implants an ion beam into the outer periphery of a hollow or solid cylindrical material while rotating the cylindrical material, an ion beam barrier is arranged on the outer periphery of the cylindrical material and the beam is directed to the outer periphery of the cylindrical material. An ion beam mixing device that is characterized by surface modification by limiting the incident angle.