JP2612554B2 - Method for fixing target in sputtering apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) In the present invention, in a sputtering apparatus for forming an aluminum film or the like on a substrate surface such as a compact disk, a target is screwed and fixed to a backing plate. Related to improvement of target fixing method.

(Prior Art) Compact discs (hereinafter abbreviated as CDs) have been widely used for recording a large amount of digitized audio images and image information.

The CD is formed by forming an aluminum (Al) thin film layer having a high light reflectance by sputtering on the surface of a transparent synthetic resin substrate such as polycarbonate, and according to the digital information of "1" or "0", A small hole called a pit is formed in the substrate, and the presence or absence of the hole can be read out based on the presence or absence of a reflected or transmitted wave of laser light.

Since the formation of a thin film on one disk is performed in a relatively short time by sputtering, it is possible to continuously form a thin film on many disks.

A conventional sputtering apparatus, as shown in FIG.
Substrate 3 transported to sputter source 2 by transport table 1
Is pushed up by the pusher 4 so as to be in close contact with the lower end surface of the mask 22 forming the film forming chamber 21.

The deposition chamber 21 includes a deposition-inhibiting shield 23a inscribed in an envelope 23,
The substrate 23 is formed by a backing plate 25 to which the mask 22 and the target 24 are fixed, and the exhaust is exhausted from the exhaust port 26 through the space 22 a of the mask 22 when there is no substrate 3.

The mask 22 supports the substrate 3 and shields the non-film-forming portion thereof. The outer dimensions of the mask 22 are manufactured with high precision, and the mask 22 is tightly fixed to the envelope 23 by using the thermal expansion force. You.

A target 24 made of Al or the like faces the film forming chamber 21 and is fixed to the backing plate 25 by screws 25a and 25b such as bolts.

However, the surface of the target 24 facing the film forming chamber 21 is
As shown by the bold line A in FIG. 5, the portion where the line of magnetic force B by the magnet 27 is parallel to the target 24 is most etched. Therefore, the magnet 27 is made of a permanent magnet and the central magnet 27a
And surrounding magnets 27b arranged in a circle to surround it
The target 24 is eccentrically positioned at a distance d from the center position C of the target 24 for the purpose of uniform etching, and is rotationally driven about the position C by a motor.

In this manner, since the target get 24 is etched over substantially the entire surface, except for the target outer peripheral flange portion fixed with the screw 25b, the large-sized screw 25a fixing the center portion is, as shown, from the backing plate 25 side. Was installed.

The backing plate 25 constitutes a cathode electrode and forms a discharge electric field of about 75 W / cm ^{2 on the} surface of the target 24,
Generates considerable heat. 200-300 surface temperature rise due to heat
In order to prevent the target 24 from deforming or forming a gap with the backing plate 25, a ring-shaped cavity is formed in the backing plate 25,
Cooling water is supplied via 25c.

At the time of film formation on the substrate 3, argon gas necessary for film formation
The pressure is set to about 0.6 [Pa (Pascal)] supplied from 23c, and a sputtering action by argon gas ions occurs under the formed discharge magnetic field, and Al
Is formed. After the formation of the thin film, the discharge is stopped, and the substrate 3 is placed again on the transfer table 1 and taken out.

In the sputtering apparatus having the above configuration, the target
24 are consumables that often need to be replaced. However, the target 24 is fixed with screws 25a from the backing plate 25 side at the center, apart from the peripheral flange, so to replace the target 24, it is necessary to remove the screws 25a after removing the magnet 27. is there. Moreover, the magnet 27 is in the case 28,
Since the water supply pipe 25c is connected between the case 25 and the case 28, replacing the target 24 requires complicated disassembly work, and requires much labor and high technical skills, so improvement is required. It had been.

(Problems to be Solved by the Invention) According to the conventional method of fixing a target in a sputtering apparatus, the target replacement operation is not easy because the central portion of the target is screwed and fixed from the backing plate side.

Therefore, an object of the present invention is to provide a method for fixing a target in a sputtering apparatus that is easy to remove.

[Structure of the Invention] (Means for Solving the Problems) A method for fixing a target in a sputtering apparatus according to the present invention is a method for fixing a target to a backing plate with a screw so as to face a substrate in a film forming chamber. In the method of fixing the target, after substantially fixing the substantially central portion of the target and the outer peripheral flange portion of the target to the backing plate by screwing from the film forming chamber side, the plurality of claw portions having spring properties are provided on at least a part of the distal end portion. A bottomed cylindrical sealing member of the same quality as the target is formed, and the claw portion is fitted into the concave portion of the central threaded portion of the target so that the exposed surface of the sealing member can be freely attached to and detached from the target without irregularities. It is characterized by sealing.

(Operation) In the method for fixing a target in the sputtering apparatus according to the present invention, since the target is fixed to the backing plate by screws from the film forming chamber side, the target can be easily replaced without removing the magnet. In addition, the sealing member of the same quality as the target is detachably sealed in the central screw portion, so that the screw is prevented from being etched,
Avoid contamination of the deposition chamber. Further, the sealing member is formed by providing a plurality of claw portions having a resiliency at least at a part of a distal end portion with a bottomed cylindrical shape, and fitting the claw portion into a concave portion of the central screw portion of the target to seal. By doing so, the mounting of the sealing member is ensured, the etching of the screw is prevented, and the target can be easily replaced.

(Embodiment) An embodiment of a method for fixing a target of a sputtering apparatus according to the present invention will be described below with reference to FIGS. The same components as those of the conventional sputtering apparatus shown in FIGS. 4 and 5 are denoted by the same reference numerals, and detailed description is omitted.

That is, the film forming chamber 21 is constituted by a deposition-inhibiting shield 23d inscribed in the mask 22 and the envelope 23, and a backing plate 25 to which the target 24 is fixed.

Therefore, as in the conventional case, an argon gas flows from the tube 23c into the film forming chamber 21, and an Al thin film is formed on the surface of the substrate 3 opposed to the surface by the sputtering action using the argon gas ions. After the film is formed, the discharge is stopped as in the related art, and the substrate 3 is placed on the transfer table and taken out.

By the way, the target 24 made of Al or the like faces the inside of the film forming chamber 21 and is fixed to the backing plate 25.The center part is formed by screws 25a such as bolts, and the outer peripheral flange part is formed by a plurality of relatively small screws 25b. Each is screwed and fixed from the target 24 side to form a cathode electrode. The cathode electrode forms a magnetic field in the film forming chamber 21 together with the magnet 27 that rotates eccentrically as in the related art.

In this embodiment, the head of the screw 25a is mounted with the head positioned deep in the central recess 24a of the target 24, and as shown in an enlarged view in FIG. 2, the screw 25a is covered, and the recess 24a is made of the same quality as the target 24. For example, it is sealed with a lid-shaped sealing member 29 made of an Al member, and is configured to be substantially the same as the surface of the target 24 and to have no irregularities.

The sealing member 29 is formed in a cylindrical shape with a bottom as shown in FIG.
As a result, a plurality of claw portions 29b having a spring property with the tip portions slightly bent outward are formed. Since the tip 29b 'of the claw 29b of the sealing member 29 is formed so as to fit into the ring-shaped groove 24a' formed in the recess 24a of the target 24,
The sealing member 29 is attached by a one-touch operation by a pushing operation, and is prevented from falling into the film forming chamber 21. In addition, the slit 29a of the sealing member 29 has a function of discharging the gas in the concave portion 24a simultaneously with the exhaust processing of the film forming chamber 21.

When the sealing member 29 is to be removed, it can be easily removed by pressing and narrowing the claw portion 29b with a thin metal fitting.

As described above, according to the target fixing method of the present invention, the sealing member 29 made of the same material as the target 24 is used.
Since the screw 25a in the central portion is sealed with the screw 25a made of a different material is not exposed to the film forming chamber 21 side, it is possible to prevent abnormal discharge and contamination of the film forming chamber 11 beforehand, Magnet 27, backing plate 25 and target 24
The target 24 can be easily exchanged from the film forming chamber 21 side only by integrally separating the target 24 from the envelope 23 side with the screw 23e.

[Effects of the Invention] In the method for fixing a target in a sputtering apparatus according to the present invention, the target is fixed to the backing plate by screws from the film forming chamber side, so that the target can be easily replaced without removing the magnet. In addition, by sealing the sealing member of the same quality as the target to the center screw portion in a detachable manner, the screw is prevented from being etched, and the deposition chamber is prevented from being contaminated. Further, the sealing member is formed by providing a plurality of claw portions having a resiliency at least at a part of a distal end portion in a bottomed cylindrical shape, and fitting the claw portions into recesses of the central screw portion of the target for sealing. By doing so, the mounting of the sealing member is assured, and the exposed surface of the sealing member is sealed to the target without unevenness, so that the screw can be prevented from being etched, and the target can be easily replaced and detached, so that the target can be easily replaced.

As described above, good sputtering can be performed, and a remarkable effect can be obtained by applying the present invention to, for example, a sputtering apparatus for forming a continuous CD thin film.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a method for fixing a target in a sputtering apparatus according to the present invention, FIG. 2 is an enlarged sectional view of a screwed portion by the method shown in FIG.
FIG. 4 is an enlarged perspective view of a lid used in the method shown in FIG. 1, FIG. 4 is a cross-sectional view showing a method for fixing a target in a conventional sputtering apparatus, and FIG. 5 is a magnetic field line by a magnet in the method shown in FIG. FIG. 4 is an explanatory diagram showing a situation of occurrence of an error. 1 ... transfer table, 2 ... sputter source, 21 ... film forming chamber, 22 ... mask, 23 ... envelope, 24 ... target, 25 ... backing plate, 25a, 25b ... screws, 27 ... magnet, 28 ... case, 29 ... sealing member, 3 ... board.

Continuing from the front page (72) Inventor Kyoji Kinokiri 6-25-22 Sagamigaoka, Zama City, Kanagawa Prefecture Inside Tokuda Seisakusho Co., Ltd. (72) Inventor Jiro Ikeda 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sonny (56) References JP-A-63-161163 (JP, A) JP-A-58-197271 (JP, A) JP-A-63-154661 (JP, U) JP-A-60-102249 (JP, A) U)

Claims (1)

(57) [Claims] In a method of fixing a target in a sputtering apparatus, wherein a target is screwed and fixed to a backing plate so as to be opposed to a substrate in a film forming chamber, a substantially central portion of the target and a target outer peripheral flange portion are disposed on the side of the film forming chamber. From the backing plate to form a bottomed cylindrical sealing member of the same quality as the target having a plurality of claw portions having resilience at least at a part of the tip portion, and a central screw of the target. A method for fixing a target in a sputtering apparatus, wherein the claw portion is fitted into a concave portion of the portion, and the exposed surface of the sealing member is detachably sealed to the target surface without irregularities.