JP2001214263A - Film deposition system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition system capable of securely preventing the reduction of the cooling effect of a target caused by thermal deformation. SOLUTION: This system is provided with a planar target 1 containing grains for film deposition and a coolable backing plate 2 having a cooling face 2a arranged oppositely on the back side 1a of the target 1. The target 1 has a bottomed tapped hole 7 formed on the center of the back side 1a of the target 1 by tap working. The backing plate 2 has a screw 8 projectingly disposed on the cooling face 2a and helically fitted to the bottomed tapped hole 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus, and more particularly to a film forming apparatus for performing a film forming process on a substrate surface by particles emitted from a target by sputtering.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a liquid crystal display substrate manufacturing process, or a disk manufacturing process such as a compact disk and a mini disk, a film forming apparatus is used to form a film on a substrate surface. One of the film forming apparatuses is a sputtering apparatus, a typical example of which is a planar magnetron sputtering apparatus.

In a planar magnetron sputtering apparatus, ions (eg, argon ions) generated by a discharge in a vacuum state collide with a target serving as a cathode, and particles constituting the target are emitted by sputtering. The substrate is disposed so as to be spaced apart from the target and constitutes an anode, and particles emitted from the target are deposited on the surface of the substrate, whereby a film forming process is performed.

[0004] Here, since the target in use has a high temperature, it is necessary to cool the target by an appropriate cooling means. Therefore, conventionally, the backing plate disposed on the back side of the target is cooled, and the back side of the target is cooled by the low-temperature backing plate.

FIG. 3 is a longitudinal sectional view showing a target of a conventional sputtering apparatus and its periphery. A disk-shaped target 30 is disposed on a backing plate 31 so as to face the substrate S. A carbon sheet 32 is interposed between the backing plate 31 and the backing plate 31. A flange 33 is formed on the outer peripheral edge of the target 30, and a pressing ring 34 that engages with the flange 33 is fixed to the backing plate 31 by bolts 35, thereby fixing the target 30 to the backing plate 31. are doing. And backing plate 3
The target 30 is configured to be cooled by a so-called indirect cooling method by cooling 1 with an appropriate cooling medium.

[0006]

However, in the conventional sputtering apparatus shown in FIG. 3, the outer peripheral portion of the target 30 is fixed. There is a problem that the central portion of the target 30 is warped toward the substrate S due to thermal deformation at the time of discharge, and the adhesion between the backing plate 31 and the target 30 is lost, thereby reducing the cooling effect.

In order to prevent the center of the target 30 from warping, for example, as shown in FIG. 4, a through hole 36 is formed in the center of the target 30 so as to penetrate from the front surface to the back surface. The fixed bolt 37 is screwed into a screw hole formed in the backing plate 31 to fix the center of the target 30.

However, in this method, the target 3
Since it is necessary to make a hole on the surface side of the target 30, a non-sputtered area is formed at the center of the target 30. For this reason, the sputtered particles return to the target 30 side to form a film, which causes problems such as generation of particles due to peeling of the film and generation of arc discharge.

FIG. 5 shows a configuration for ensuring the close contact between the target 30 and the backing plate 31 even when the target 30 is warped. In this configuration, the cooling medium for the backing plate 31 is used. The surface of the backing plate 31 is pressed against the back surface of the target 30 by using the pressure of water, whereby the adhesion between the back surface of the target 30 and the surface of the backing plate 31 is ensured.

However, in the configuration shown in FIG. 5, it is necessary to ensure the flexibility of the backing plate 31 so that the strength of the backing plate 31 is reduced.
The dust may be interposed between the backing plate 31 and the backing plate 31, and the backing plate 31 may be broken. Further, pressure may be applied to the target 30, which may lead to deformation of the target 30 or breakage in the case of a ceramic target. There is.

There has been a problem that it is easy.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a film forming apparatus capable of reliably preventing a cooling effect of a target from being reduced by thermal deformation. .

[0013]

In order to solve the above-mentioned problems, a film forming apparatus according to the present invention comprises a plate-like target containing particles for film formation, and a cooling surface opposed to the rear surface of the target. And the target has a bottomed screw hole formed by tapping at the center of the back surface of the target,
The backing plate has a screw protruding from the cooling surface and screwed into the bottomed screw hole.

Preferably, the target has a target main body composed of particles for film formation, and a backing layer integrally formed on the back surface of the target main body. It is formed inside the backing layer.

Preferably, the apparatus further comprises means for fixing an outer peripheral portion of the target to the backing plate.

Preferably, the cooling surface of the backing plate has flexibility.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a film forming apparatus according to an embodiment of the present invention will be described with reference to FIG. The film forming apparatus according to the present embodiment is obtained by partially changing the configuration of the conventional film forming apparatus (sputtering apparatus) shown in FIG.

FIG. 1 is a vertical sectional view showing a target of the film forming apparatus according to the present embodiment and its peripheral portion.
A disk-shaped target 1 is disposed on a backing plate 2 so as to face the target, and a carbon sheet 3 is interposed between the target 1 and the backing plate 2.
A flange 4 is formed on the outer peripheral edge of the target 1,
A holding ring 5 that engages with the flange portion 4 is fixed to the backing plate 2 with bolts 6. The target 1 is entirely composed of particles for film formation.

In the present embodiment, a bottomed screw hole 7 is formed at the center of the back surface 1a of the target 1 by tapping. On the other hand, a screw 8 protrudes from the cooling surface 2 a of the backing plate 2, and the screw 8 is screwed into a bottomed screw hole 7 on the back surface 1 a of the target 1.

When attaching the target 1 to the backing plate 2, first, the carbon sheet 3 is placed on the cooling surface 2 a of the backing plate 2. Here, since the hole 3a is formed in the center of the carbon sheet 3, the screw 8 is passed through the hole 3a. Next, target 1
The screw 8 is screwed into the bottomed screw hole 7 while rotating the target 1 while aligning the bottomed screw hole 7 on the back surface 1a with the screw 8. Finally, a retaining ring 5 is attached to the flange 4 of the target 1.
And the holding ring 5 is fixed to the backing plate 2 with bolts 6. As a result, the target 1 is fixed to the backing plate 2 at the central portion and the outer peripheral portion.

As described above, in the film forming apparatus according to the present embodiment, not only the outer peripheral portion but also the central portion of the target 1 is fixed to the backing plate 2, so that even if the target 1 No warpage occurs in 1. For this reason, the adhesion between the back surface 1a of the target 1 and the cooling surface 2a of the backing plate 2 is reliably maintained, and a decrease in the cooling effect of the target 1 can be reliably prevented.

The bottomed screw hole 7 is formed on the back surface 1a side of the target 1, and no hole is formed on the front surface 1b side of the target 1.
Does not have a non-sputtering area, and is entirely eroded. For this reason, there is no problem of film peeling or arc discharge at the hole on the target surface as in the conventional film forming apparatus shown in FIG.

A screw 8 projecting from the backing plate 2 and a bottomed screw hole 7 formed in the back surface 1a of the target 1
Are fixed by screwing them together, so that there is a problem of dust trapping and a problem of reduced strength of the backing plate as in the conventional film forming apparatus having a flexible backing plate shown in FIG. Does not occur.

Next, a first modification of the above embodiment will be described with reference to FIG. This modification is a partial modification of the configuration of the target 1 in the film forming apparatus shown in FIG. 1. The target 1 in this modification includes a target body 10 composed of particles for film formation, The backing layer 11 is integrally formed on the back surface of the target main body 10.

The bottomed screw hole 7 is formed inside the backing layer 11 without penetrating to the target body 10.

In this modification, the bottomed screw hole 7 is formed inside the backing layer 11, so that even when a ceramic-based hard-to-machine target body 10 is used, the hole is formed in the target body 10. Since it is not necessary to form it, an increase in processing cost can be prevented.

Next, as a second modification of the above embodiment,
Instead of providing the carbon sheet 3, the cooling surface 2a of the backing plate 2 is made flexible, and the target 1 and the backing plate 2 are brought into close contact by utilizing the pressure of water as a cooling medium in the backing plate 2. As a result, the heat transfer between the target 1 and the backing plate 2 can be sufficiently ensured. Note that the same configuration as that of the present modification can be applied to the first modification.

In this modification, since the central portion of the target 1 is fixed to the backing plate 2, the cooling surface 2a of the backing plate 2 is made flexible so that the water pressure is applied to the target 1. However, no excessive stress is generated in the target 1.

[0029]

As described above, according to the film forming apparatus of the present invention, since the center of the target is fixed to the backing plate, the target does not warp even when discharged at a high power. . Therefore, it is possible to reliably maintain the adhesion between the back surface of the target and the cooling surface of the backing plate, and to reliably prevent the cooling effect of the target from decreasing.

Further, since the bottomed screw hole is formed on the back surface side of the target and no hole is formed on the front surface side of the target, there is no non-sputter area on the surface of the target and the entire surface is eroded. . For this reason, there is no problem of film peeling or arc discharge at the hole on the target surface as in the conventional film forming apparatus.

Further, since the screw protruding from the backing plate and the bottomed screw hole formed on the back surface of the target are screwed together to fix both, a conventional film forming method having a flexible backing plate is used. There is no problem of trash being trapped in the device or a problem of a decrease in the strength of the backing plate.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a target and its periphery of a film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a target and its periphery of a film forming apparatus according to a first modification of the embodiment shown in FIG. 1;

FIG. 3 is a longitudinal sectional view showing a target of a first example of a conventional film forming apparatus and its periphery.

FIG. 4 is a longitudinal sectional view showing a target of a second example of the conventional film forming apparatus and its periphery.

FIG. 5 is a longitudinal sectional view showing a third example of a conventional film forming apparatus and its periphery.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 target 1a back surface of target 2 backing plate 2a cooling surface of backing plate 3 carbon sheet 4 flange portion of target 5 holding ring 6 bolt 7 bottomed screw hole 8 screw 10 target body 11 backing layer S substrate

Claims (4)

[Claims] 1. A target comprising: a plate-like target containing particles for film formation; and a coolable backing plate having a cooling surface opposed to a rear surface of the target. A film having a bottomed screw hole formed by tapping at the center of the back surface, wherein the backing plate has a screw protruding from the cooling surface and screwed into the bottomed screw hole. apparatus. 2. The target according to claim 1, wherein said target has a target main body made of particles for film formation, and a backing layer integrally formed on a back surface of said target main body. The film forming apparatus according to claim 1, wherein the film forming apparatus is formed inside. 3. The film forming apparatus according to claim 1, further comprising: means for fixing an outer peripheral portion of said target to said backing plate. 4. The film forming apparatus according to claim 1, wherein the cooling surface of the backing plate has flexibility.