JPH01239432A - Sputtering device - Google Patents

Abstract

PURPOSE:To form a uniform thin film on a sample in a short time by providing a beltlike target along an arc and plural magnets along its outer peripheral surface, and rotating a rotary shaft provided on the plane containing the arc for electric discharge. CONSTITUTION:When a negative voltage is applied to the target 19 through an electrode rod 27 and the shaft 21, the discharge is caused between the target 19 and electrode 16 and ions strike on the target 19 to sputter atoms. Then the atoms are scattered toward to the sample 18. Here, when a motor 22 is driven to rotate the target 19 around the rotary shaft C, the beltlike target 19 draws a bowl-shaped track. Therefore, the target material sticks on the sample 18 to uniform thickness with the scattered atoms. Further, magnetic fields F1-F6 are provided in front of the target 19 and a large amount of ions strike on the target to form the thin film in short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a sputtering apparatus suitable for use in forming a thin film on a sample for an electron microscope or the like.

[Conventional technology] A conventional example of such a sputtering apparatus is shown in FIG.

That is, the target 2 and the electrode 3 are placed facing each other in a container 1 maintained at a vacuum level of, for example, about 10' to 10-2 Torr, and the target is kept at a high negative potential with respect to the electrode. A DC power source 4 is connected as shown in FIG. 3, and a sample 6 is placed on the electrode 3 via a sample holder 5.

In this configuration, when a high voltage of, for example, IKV is applied between the target 2 and the electrode 3 by the power source 4, a glow discharge occurs between the two, and the resulting cations are kept at a negative potential. It accelerates toward the leaning target 2 and collides with it. This collision of positive ions causes a so-called sputtering phenomenon in which atoms on the target surface are scattered, so that the scattered target atoms adhere to the sample 6 and form a thin film of the target material on the sample surface.

If the sputtering phenomenon is caused in an atmosphere where the pressure is relatively high, for example, about 10-1 to -2 TOrr, the sputtered atoms from the target 2 will not go straight, but will move in the atmosphere as shown by the arrow in the figure. Since the target atoms reach the surface of the sample 6 while repeatedly colliding with gas molecules, they adhere to the sample 5 from all directions. Therefore, a thin film with a uniform thickness can be formed on the sample surface.

However, on the other hand, since the pressure is high, the particles of the thin film formed on the sample surface become coarse, and the coating speed becomes slow.

In order to prevent such inconveniences, magnetron sputtering equipment is widely used, which efficiently generates ions by glow discharge by forming a magnetic field F between the target 2 and the electrode 3, as shown in Fig. 5. It is used.

In the figure, a target 2 is formed into an annular shape, and magnetic poles 7.8 for forming a magnetic field F are placed on the inside and outside of the target 2. 9 is a yoke for connecting each magnetic pole, 10
1 is a permanent magnet, and 11 is a shield for preventing discharge.

According to this configuration, the pressure inside the container 1 is reduced to 10-4, for example.
Even if the temperature is as low as ~10"6 Torr, since the discharge occurs in the magnetic field F, the electrons are bent by the magnetic field and the electron trajectory becomes longer, thereby improving the ion generation efficiency per unit time. This increases the coating speed and allows the target material to be deposited in a short time.Furthermore, since coating is performed in a low pressure atmosphere, a thin film with very fine particles can be obtained.

On the other hand, however, because the pressure is low, most of the atoms sputtered from the target by ion irradiation do not collide with gas molecules in the atmosphere and reach the sample in a straight line. Therefore, sputtering is performed from a fixed direction, making it impossible to form a uniform thin film.

[Problems to be Solved by the Invention] Therefore, by using the rotating planetary movement mechanism 12 between the sample holder 5 and the electrode 3, it becomes necessary to perform sputtering while rotating and revolving the sample 6, which makes the structure complicated. This results in an increase in costs and increases the size of the sample.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a magnetron sputtering apparatus that can form a thin film of uniform thickness on a sample without using a rotating planetary movement mechanism.

[Means for Solving the Problems] In order to achieve the above object, the sputtering apparatus of the present invention includes a band-shaped or linear target arranged along an arc centered on a sample, and a sputtering device arranged along an outer peripheral surface of the target. A voltage is applied between a plurality of magnets arranged such that adjacent magnetic poles are the same as each other, a container kept in a vacuum to accommodate these members, and the target and the sample. and a means for generating an electric discharge,
The present invention is characterized in that a discharge is generated while either the target or the sample is rotated about a rotation axis that passes through the sample and is provided on a surface that includes the circular arc.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[Example] Fig. 1 is a cross-sectional view showing an example of a magnetron sputtering apparatus used in the present invention, Fig. 2 is an enlarged cross-sectional view taken along line AA in Fig. 1, and Fig. 3 is a view taken along arrow BB.

In the figure, 13 is a base, 14 is a glass cylindrical container placed airtightly on the base, 15 is a lid removably attached to the upper end of the container, and 16 is a An electrode fixed on a base inside this container 13 is maintained at ground potential. A sample holder 17 is attached to the upper surface of this electrode and holds a sample 18 therein.

Reference numeral 19 denotes a target placed above the sample 18, and this target is a band-shaped object formed into an arc shape. Further, the sample 18 is placed at the center of this circular arc. Furthermore, a plurality of rectangular permanent magnets 20a to 2Of are fixed to the outer peripheral surface of the target, respectively. These permanent magnets are arranged so that adjacent magnetic poles have the same polarity as shown in FIG. As a result, a plurality of magnetic fields are formed along the longitudinal direction in front of the inner surface of the magnet 19 (the surface facing the sample), as indicated by arrows F1 to F6 in the figure.

Reference numeral 21 denotes a shaft for supporting the target 17 at its lower end, and the axis of this shaft passes through the sample 18 and coincides with the rotation axis C provided on the surface including the circular arc. This shaft passes through the lid 15 and is taken out to the outside, and its tip is electrically insulated and connected to the motor 22 via an electrical insulator (not shown). In addition, the lid body 13 of this shaft
An outer cylinder 24 is integrally fixed to the penetrating portion through a collar 23 made of an electrical insulator, and this outer cylinder is rotatably supported by a bearing 25 fixed to the lid body 15.

Reference numeral 26 denotes a support base for the motor 22, and 27 represents an electrode rod provided through the support base 25, the tip of which is brought into contact with the outer periphery of the shaft 21 by a spring. Further, this electrode rod is connected to a DC power source (not shown) via a lead wire 28, and is connected to a target 19 with a voltage of, for example, 300 volts for the sample 18.
Apply a negative voltage of about ~500V. The second shield body is arranged to surround the target 17 and the magnet with a slight spacing between them, and is used to prevent discharge from occurring on the outer peripheral side of the target. The shield body is fixed to the lower end of the outer cylinder 24.

In such a configuration, lead wire 28. When a negative voltage of about 300V to 500V is applied to the target 19 via the electrode rod 27 and the shaft 21, a discharge occurs between the target and the electrode 16, and the resulting ions collide with the target. Atoms on the inner surface of the target are sputtered. This sputtered atom is the first
As shown by arrow S in the figure, it scatters and adheres to the sample 16. In this state, the motor 22 is driven and the shaft 21
and the target 19 (shield body 29
) is rotated around the rotation axis C, this belt-shaped target will draw a bowl-shaped trajectory as shown by the dotted line in FIG. As a result, atoms sputtered from substantially the entire inner surface of the bowl-shaped target are scattered and attached to the sample 18, so that a uniform thickness of the target material is attached to the sample. Here, since multiple magnetic fields Fl to F6 are formed in front of the target, the amount of ions generated per unit time increases, and a large number of ions collide with the target, forming a thin film in a short time. .

It should be noted that the above description is an example of the present invention, and many modifications can be made in implementing the present invention. For example, in the above embodiment, the target is rotated, but the sample may be rotated about the rotation axis C, on the contrary.

Further, although the target is formed in a band shape, the present invention is not limited to this, and a linear member formed in an arc shape may be used.

Furthermore, although permanent magnets were used in the above embodiments, electromagnets may also be used.

[Effects] As detailed above, according to the present invention, a uniform thin film can be deposited on a sample in a short time without rotating or revolving the sample using a rotating planetary motion mechanism, which simplifies the structure. In addition to being able to reduce costs, it is also possible to form a thin film on a sample of any size.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a magnetron sputtering apparatus used in the present invention, FIG. 2 is an enlarged sectional view taken along line AA in FIG. FIG. 2 is a diagram for explaining a conventional example. 14: Container 15: Lid body 16: Electrode, 18: Sample 19: Targets 20a to 20f: Permanent magnet 21: Shaft 22: Motor 25: Bearing 29: Shield body C: Rotating shaft

Claims (1)

[Claims] a strip-shaped or linear target arranged along an arc centered on the sample; a plurality of magnets arranged along the outer peripheral surface of the target so that adjacent magnetic poles are the same; A container kept in a vacuum to accommodate these members, and means for applying a voltage between the target and the sample to generate an electric discharge, the apparatus comprising: a container that is kept in a vacuum to accommodate these members; A sputtering apparatus characterized in that the sputtering apparatus is configured to generate electric discharge while rotating either the target or the sample around a rotation axis provided in the sputtering apparatus.