JP2000290772A - Sputtering target - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join a sputtering target without bonding and to facilitate the recovery of a backing plate by screwing a disk-shaped target helically threaded in the outer circumference of the bottom part and a backing plate helically threaded in the side face of the recessed part. SOLUTION: A helical thread is cut on the outer circumference of the bottom part of a disk-shaped target 1. On the other hand, the part to be fitted with the target 1 in a backing plate 2 of copper or the like is provided with a recessed part, and a helical thread corresponding to the thread of the target 1 is cut on the side face of the recessed part. This target 1 and backing plate 2 are screwed on a screw part 3, and the target 1 is rotated and is screwed into the backing plate 2 to join them. To this joined part 4, tin foil, indium foil or the like is interposed at need, and the cooling effect of the backing plate 2 is improved. The sputtering target obtd. by this can easily be removed and exchanged by rotating the target 1 after use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sputtering target used for forming a thin film. For more information,
It relates to a sputtering target that does not require bonding.

[0002]

2. Description of the Related Art In a sputtering method, an Ar gas is introduced into a vacuum and a negative voltage is applied to a cathode to generate a glow discharge. The generated Ar ⁺ ion is the target (cathode)
This is a technique in which a target is sputtered and particles to be sputtered are deposited on a substrate on an opposed anode to form a thin film.

Generally, a target used in this sputtering method is used by bonding it to a backing plate with a bonding material. Normally, the backing plate is made of pure copper or a copper alloy, and the bonding material is a low melting point metal such as indium, a low melting point alloy such as solder,
A resin or the like is used.

[0004] In this case, the backing plate is recovered when the target is used, the remaining target is peeled off from the backing plate, and a new target is bonded to the backing plate with a bonding material. In other words, the backing plate is repeatedly reused until its service life comes due to deterioration of its material, shape and the like.
Therefore, there is a drawback that the transfer between the manufacturer and the user of the backing plate, quality control, and the like are required. Further, after the remaining target is peeled off from the backing plate, there is a drawback that a step of completely removing the adhered bonding material is required to reuse the backing plate.

In recent years, the mainstream of the industry is a sputtering apparatus, such as a magnetron sputtering apparatus, which sputters at a high output in order to obtain a high sputter rate. However, when the sputtering is performed at a high output, the calorific value of the cathode increases. However, there is a disadvantage that the bonding material is melted due to the high temperature and the target is separated from the backing plate. Further, this peeling also occurs due to insufficient cooling of the backing plate by the cooling water in the sputtering apparatus.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has proposed a sputtering target which does not require bonding in order to overcome the above-mentioned drawbacks. A patent application was filed earlier for an integral structure type sputtering target in which a threaded annular collar portion was joined by screwing (Japanese Patent Application No. 10-303171). The present invention relates to improvements in this patent application.

[0007]

According to the present invention, there is provided a disk-shaped target having a spiral thread formed on the outer periphery of a bottom, a concave portion provided in a portion where the target is screwed, and a spiral thread formed on a side surface of the concave portion. This is a sputtering target in which a backing plate is joined by screwing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a sputtering target according to the present invention. In the drawing, reference numeral 1 denotes a target, and the outer periphery of the bottom of the target is spirally threaded. Reference numeral 2 denotes a backing plate, and a central portion of the backing plate is a processed sectional view of the backing plate of FIG. 2 (a).
Then, as shown in Fig. 7, the lathe was processed into a concave shape, and then a spiral screw was cut on the side surface of the concave portion so as to match the screw of the target, as shown in the processed sectional view (b). The target and the backing plate are screwed together with the screw portion 3 and screwed into the backing plate while rotating the target, and are joined and fixed to the backing plate as shown in FIG. Then, when the target has been used, the target can be removed from the backing plate by reversing the target. In addition, a new target is attached to this backing and the backing plate is reused repeatedly. These operations can be easily performed by any person, whether the backing plate is attached to the sputtering device or after the backing plate is attached or detached.

In the present invention, any metal material can be used for the target 1 and the backing plate 2. However, it is preferable to select a metal having good mechanical strength and heat conductivity for the backing plate. Generally, copper, copper alloy, stainless steel, etc. are used.

In the present invention, since the target and the backing plate are joined by screwing together without joining with a bonding material, if the target or the backing plate is warped or distorted due to heat generated during sputtering, the joining is performed. It is conceivable that the joining becomes loose in the part 4 and the cooling efficiency by the cooling water decreases. In this case, it is possible to prevent a decrease in cooling efficiency by a simple measure such as sandwiching an indium foil, a tin foil, or an alloy foil thereof between the joining portion 4 between the target and the backing plate.

[0011]

EXAMPLE A silver target 1 of 170 mφ × 15 mt was prepared, and was spirally threaded at a pitch of 1 from the bottom of the target to a height of 10 mm. Next, 225mφ × 15
An mt copper backing plate was prepared, and a recess having a dimension into which the target was screwed was formed by lathe processing, and a spiral thread having a pitch of 1 was formed on the side surface of the recess so as to match the screw of the target. The target was fixed by screwing it into the backing plate while rotating the target. This target was mounted on a sputtering apparatus and sputtered. After using the target, the target was removed from the backing plate, and a new target was screwed into the backing plate and subjected to sputtering. When this operation was repeated, the backing plate could be reused repeatedly 30 times.

[0012]

According to the present invention, since the target and the backing plate are joined by screwing without using a bonding method, the target may be separated from the backing plate even when sputtered at a high output. There are no features. Further, since the attachment and detachment of the backing plate and the target are easy, there is an effect that the exchange efficiency of the target is improved. Further, since there is no bonding step and no step of removing the bonding material adhered to the backing plate, there is an advantage that the processing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a sputtering target according to the present invention.

FIG. 2 is a cross-sectional view of a processing of a backing plate.

[Explanation of symbols]

 1. Target 2. Backing plate 3. Screw part 4. Joint

Claims (1)

[Claims] 1. A disk-shaped target having a spiral thread cut on the outer periphery of a bottom, and a backing plate having a concave portion provided in a portion into which the target is screwed and having a spiral screw thread formed on a side surface of the concave portion. A sputtering target which is joined by screwing.