JPH02277771A - Magnetron sputtering device - Google Patents

Abstract

PURPOSE:To increase the rate of effective utilization of a target by arranging plural pairs of magnets at different intervals from the center of a holding plate or from a target. CONSTITUTION:A discoid holding plate 18 is rotatably set behind a target 13 and plural pairs of magnets 12, 12A are arranged on the holding plate 18 at different intervals from the center O of the plate 18 or from the target 13 to assemble a magnetron sputtering device. When a film is formed with the device, the step coverage of the film is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetron type sputtering apparatus, and particularly to the structure of a magnet.

[Conventional technology]

Conventionally, magnetron sputtering equipment used in the manufacturing process of semiconductor devices uses the principles of leakage magnetic field type magnetron sputtering method and magnetic field pressure bonding type magnetron sputtering method.
The structure was such that the movement of secondary electrons emitted from the vicinity of the cathode promoted the ionization of Ar, and the formed Ar ions collided with a target to form a thin film on the semiconductor substrate. The following description will be made using a conventional magnetron type sputtering apparatus shown in FIG.

Secondary electrons emitted from the target 13 to which a negative potential has been applied by the target power source 11 are held by the holding plate 18 and are absorbed by the magnetic field 15 formed by the rotating magnet pair 12.
exercise under the influence of

In particular, magnetic lines of force having components parallel to the surface of the target 13 cause secondary electrons to move cycloidally on the target, promoting ionization of Ar and producing Ar ions.
The Ar ions 19 collide with the target 13, which is a cathode, and knock out the target material, which is deposited on the semiconductor substrate 17 to form a thin film.

[Problem to be solved by the invention]

In the conventional magnetron sputtering apparatus described above, the distribution of magnetic lines of force for restraining electrons emitted from the cathode surface is a single concentric circle along the rotation of the magnet pair, so the eroded region 14 of the target 13 is also affected by the magnetic field. There is a drawback that the effective utilization rate of the target 13 becomes low because the target 13 becomes single-layered. Furthermore, since the erosion region is narrow, there is also a drawback that step coverage of film formation becomes poor when the step part of the semiconductor substrate is blown away.

In contrast to the conventional magnetron type sputtering apparatus described above, the present invention provides a pair of magnets having different distances from the center of the holding plate,
Alternatively, by arranging two or more pairs of magnets with different distances from the back surface of the target and rotating them on the back surface of the target, two or more concentric magnetic fields can be formed, thereby improving the effective utilization rate of the target. There is a difference.

[Means to solve the problem]

The magnetron sputtering apparatus of the present invention has a disc-shaped rotatable holding plate disposed on the back surface of a target and a plurality of magnet pairs held by the holding plate. The holding plate is arranged at a different distance from the center or at a different distance from the target.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1 and 2 are a schematic diagram of a first embodiment of the present invention and a side view of a retaining plate.

In FIGS. 1 and 2, a plurality of magnet pairs 12.12A are provided on a holding plate 18 rotatable in the direction of the arrow on the back surface of the target 13.
2.12A are provided at different distances from the center 0 of the holding plate 18.

Secondary electrons emitted from the target 13 to which a negative potential is applied by the target power supply 11 are transferred to the center 0 of the holding plate 18.
It moves under the influence of a magnetic field 15 formed by two pairs of rotating magnets 12.12A arranged at different positions. In particular, magnetic lines of force with components parallel to the surface of the target 13 cause secondary electrons to move cycloidally on the target 13, promoting ionization of Ar and
The Ar ions 19, which produce ions 19, collide with the target 13 formed as a cathode to knock out the target material and deposit it on the semiconductor substrate 17 on the holder 16 to form a thin film.

According to the first embodiment configured in this manner, the target is eroded along the magnetic field, so that double eroded regions 14A and 14B are formed. As a result, the effective utilization rate was reduced to about 1% compared to the conventional method (40-45%).
．． It can be improved by 5 times (60-70%).

FIG. 3 is a schematic diagram of a second embodiment of the present invention.

In this second embodiment, two pairs of magnets 12.12B are provided at equal positions from the center of the rotating holding plate, but at different distances from the target. This is similar to the first embodiment.

In the second embodiment configured in this way, the effective utilization rate is approximately 1.3 times (50 to 60%) compared to the conventional method.
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〔Effect of the invention〕

As explained above, the present invention makes effective use of the target by arranging a plurality of pairs of magnets on the back surface of the target at different positions from the center of the holding plate, or by arranging them at different distances from the back surface of the target and rotating them. This has the effect of increasing the rate. Further, by expanding the erosion region of the target, there is an effect that the step coverage of film formation is improved in the case of scattering on the stepped portion of the semiconductor substrate.

[Brief explanation of drawings]

1 and 2 are a schematic diagram of the first embodiment of the present invention and a side view of the holding plate, FIG. 3 is a schematic diagram of the second embodiment of the present invention, and FIG. 4 is a conventional magnetron type FIG. 2 is a schematic diagram of a sputtering device. 11...Target power supply, 12.12A, 12B...
・Magnet pair, 13...Target, 14.14A
, 14B... Erosion area, 15... Magnetic field, 16...
Holder 17... Semiconductor substrate, 18... Holding plate.

Claims (1)

[Claims] In a magnetron type sputtering apparatus having a disc-shaped rotatable holding plate disposed on the back surface of a target and a plurality of magnet pairs held by the holding plate, the distance between the magnet pairs and the center of the holding plate is A magnetron type sputtering apparatus characterized in that the magnetron type sputtering apparatus is arranged by changing the distance from the target or by changing the distance from the target.