JPH11106903A - Sputtering target - Google Patents

Abstract

(57) [Problem] To provide a sputtering target in which erosion is averaged with respect to partial erosion of the sputtering target, the life is extended, and the utilization efficiency is improved. SOLUTION: The target material is a backing plate 2
In the sputtering target bonded to 1, a low melting metal 2
8 was charged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering target, and more particularly to a sputtering target in which a portion where a target material is eroded is filled with a low melting point metal to extend the life of the target.

[0002]

2. Description of the Related Art In general, a sputtering target for forming a film on a wafer surface by ion bombardment in a sputtering apparatus is formed by bonding a target material to a backing plate. This target
It can be used until the backing plate is exposed by erosion (erosion) by sputtering.

[0003]

However, if the target is eroded in a state parallel and uniform to its surface, almost all of the target is consumed and the target utilization rate is increased. However, in the case of the magnetron sputtering method, From the relationship of the magnetic field, as shown in FIG.
Erosion 2 as if the surface of the pit was partially eroded
Will occur. Therefore, when the bottom of the erosion portion 2 reaches the backing plate 3, the life of the target 1 expires, and the target 1 cannot be used because only a part thereof is consumed.

Further, when a rectangular target is used in the magnetron sputtering method, the plane of the rectangular target 4 is eroded in a loop shape (race track) as shown in FIG. Erosion is less likely to occur uniformly, and erosion tends to concentrate on a part of the erosion. For this reason, when the erosion progression at the positions A and B of the race track 5 is more remarkable than at the position C, the life of the rectangular target 4 is determined at the position A or B, and is still at the position C. Although it can be used, its life will end. Therefore, the utilization rate of the rectangular target 4 decreases.

The present invention has been made in consideration of the above-mentioned prior art, and aims at averaging erosion with respect to partial erosion of the sputtering target, extending the life and improving the utilization efficiency of the sputtering target. For the purpose of providing.

[0006]

In order to achieve the above object, according to the present invention, in a sputtering target in which a target material is bonded to a backing plate, a portion where the target material is eroded is filled with a low melting point metal. And a sputtering target characterized by the following.

[0007] According to the above configuration, the portion of the sputtering target in which the target material is eroded is filled with a low-melting-point metal and sputtering can be performed. Thereby, erosion can be averaged for partial erosion of the sputtering target, and the service life of the sputtering target can be increased by extending the life of the target.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory cross-sectional view of a sputtering apparatus to which a sputtering target according to an embodiment of the present invention is attached. As shown in FIG. 1, the magnetron sputtering apparatus 10 has a vacuum vessel 11 and a cathode 12 attached to the vacuum vessel 11.
The vacuum container 11 is provided with a gas inlet 13 and a vacuum exhaust port 14 communicating with a gas supply unit (not shown).
It is evacuated from the evacuation port 14 by a not-shown evacuation system. The substrate holder 1 is provided in the vacuum vessel 11 so as to face a target 22 of the cathode 12 described later.
The substrate 16 held by 5 is arranged.

The cathode 12 has a cathode mounting bolt 1
7 has a cathode housing 19 fixed to the vacuum vessel 11 via an O-ring 18. A magnet module 20, a backing plate 21 and a sputtering target (target) 22 located inside the vacuum vessel 11 are mounted on the cathode housing 19. Between the magnet module 20 and the backing plate 21, a cooling water passage 23 communicating with a cooling water inlet 23a and a cooling water outlet 23b is provided. The backing plate 21 is fixed to the O-ring 2 by bolts 24.
5 and is fixed to the cathode housing 19. The target 22 formed by bonding the target material to the backing plate 21 faces the substrate 16. An earth shield 26 covering the peripheral edge of the backing plate 21 to prevent arcing is provided.

In the magnetron sputtering apparatus 10 having the above structure, a sputtering gas supplied from a gas supply unit is introduced into a vacuum vessel 11 through a gas inlet 13 and is supplied between a cathode 12 and a substrate holder 15 by a DC power supply (not shown). When a voltage is applied, a plasma state is generated in the vacuum chamber 11, and positive ions of the sputtering gas are generated. Negative charges that generate plasma are held in the plasma region by the action of the magnet module 20. The ionized sputtering gas travels toward the cathode 12 to which the negative voltage has been applied, and collides with the surface of the target 22. As a result, particles fly out of the target 22 and a film is formed on the surface of the substrate 16 facing the target 22.

During the sputtering, when the temperature of the target 22 rises, the cooling water passage 23
Cooling water is introduced to cool the backing plate 21,
The target 22 is cooled by conducting the cooling heat. The introduced cooling water is discharged from the cooling water discharge port 23b.

FIG. 2 shows an eroded portion of the target of FIG.
It is sectional drawing which shows the state which filled the low melting point metal in the erosion part. As shown in FIG. 2, ITO (indium-tin-
As the erosion of the target 22 formed of a target material composed of oxide (oxide) progresses, the erosion portion 27 is formed such that the surface of the target 22 is partially eroded to form a hole.
Occurs, and the bottom of the eroded portion 27 is
Reach one. Since the backing plate 21 is made of a dissimilar metal such as copper, the life of the target 22 is reached at this point, and the target 22 cannot be used.

Therefore, a low-melting-point metal material composed of a metal of the composition of the target material or an alloy thereof, such as indium, tin, or an alloy thereof, is melted into the eroded portion 27 formed on the target 22 to form a low-melting-point metal. Fill 28.

As described above, a metal material similar in composition to the target material, such as a metal or an alloy thereof, of the composition of the target material is cast into a portion of the target 22 where the erosion has progressed, so that the eroded portion is formed. Backing plate 2
1 can be prevented from forming a film on the substrate 16 by sputtering. If the material to be filled in the eroded portion is similar to the composition of the target material, the sputtering can be continued without adversely affecting the film formation by the sputtering as compared with the material for forming the backing plate. When a rectangular target is used, the end portions of the race track where erosion progresses remarkably (A, B in FIG. 4)
) Is filled with the low-melting point metal 28, but the influence of deposition is small from the filling position distant from the center of the rectangular target.

The filling of the low melting point metal 28 is performed by replenishing the erosion portion 27 formed in the target 22 with a low melting point metal material such as indium or tin or an alloy thereof, and refilling the target 22 with the low melting point metal material. This is performed by using a heating device such as a hot plate together with the backing plate 21 to heat and fuse the entire material to the melting point of the low melting point metal material or higher.

Next, an example in which a sputtering target whose target life is extended by filling with a low melting point metal is used will be described below. When a magnetron sputtering apparatus equipped with a dual magnetron type cathode was used to sputter a rectangular ITO ceramic target having a thickness of 6 mm, the end portion of the race track (see FIG. 4) was consumed up to the backing plate. The thickness near the center was still 2 mm.

Therefore, the target is removed together with the backing plate from the cathode of the sputtering apparatus, and the exposed target erosion portion of the backing plate is exposed to I.
T metal (an alloy of 90% indium and 10% tin) was supplemented, and the whole was heated to about 150 ° C. on a hot plate. By this heating, the IT metal was melted and fused to the target, and the eroded portion was filled with the IT metal. Thereafter, the target filled with the IT metal was cooled down to room temperature together with the backing plate, attached again to the cathode, and sputtered. As a result, a film could be formed almost as before the filling with the low melting point metal.

This dual magnetron type sputtering apparatus has a feature that two cathodes are arranged in parallel, and arcing hardly occurs when sputtering an oxide or the like, and is stable. Erosion was likely to occur on the diagonal portions of the two rectangular targets arranged in. However, the sputtering target 22 of the present invention can extend the life of the target by filling a portion having large erosion with a low melting point metal.
By using the dual magnetron type, a dual magnetron type sputtering apparatus can be used effectively by utilizing the features of the dual magnetron type.

Therefore, with the sputtering target 22 according to the present invention, erosion can be averaged for partial erosion of the target 22, and the life of the target can be extended, and the utilization efficiency of the target 22 can be increased. As a result, a part of the target 22 is eroded to the vicinity of the backing plate 21, and even if the conventional target life is reached, the eroded part is filled with the low-melting metal by melting the low-melting-point metal material into the part, and the Target 22
Can be further used.

Further, when a low melting point metal material is cast into the target 22 using a heating device such as a hot plate, the filling operation of the low melting point metal can be performed at the sputtering site. Loss and efficiency.

[0021]

As described above, according to the sputtering target of the present invention, the portion where the target material of the sputtering target is eroded is filled with the low melting point metal and the sputtering can be performed. Erosion can be averaged for partial erosion, and the use efficiency of the sputtering target can be increased. As a result, even if the conventional target life is reached, the target life can be extended by continuing to use the sputtering target.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a sputtering apparatus to which a sputtering target according to an embodiment of the present invention is attached.

FIG. 2 is a cross-sectional view showing an eroded portion of the target of FIG. 1 and a state in which the eroded portion is filled with a low melting point metal.

FIG. 3 is a cross-sectional view showing an eroded state of a conventional target.

FIG. 4 is a cross-sectional view showing a race track of a conventional target.

[Explanation of symbols]

10: magnetron sputtering apparatus, 11: vacuum vessel, 12: cathode, 13: gas inlet, 14: vacuum exhaust port, 15: substrate holder, 16: substrate, 17: cathode mounting bolt, 18: O-ring, 19: cathode Housing, 20: magnet module, 21: backing plate, 22: sputtering target, 23: cooling water passage, 23a: cooling water inlet, 23b: cooling water outlet, 24: bolt, 25: O-ring, 26: earth shield , 27: eroded portion, 28: low melting point metal.

Claims (4)

[Claims] 1. A sputtering target in which a target material is bonded to a backing plate, wherein a portion where the target material is eroded is filled with a low melting point metal. 2. The low-melting-point metal is obtained by replenishing an eroded portion with a low-melting-point metal material and heating it together with the backing plate to a temperature equal to or higher than the melting point of the low-melting-point metal material. Item 2. The sputtering target according to item 1. 3. The sputtering target according to claim 1, wherein the low-melting-point metal is a metal of the composition of the target material or an alloy thereof. 4. The sputtering target according to claim 3, wherein said target material is made of ITO, and said low melting point metal is indium, tin or an alloy thereof.