JP2000192233A - Sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easily maintainable earth shield which solves troubles caused by thermal expansion without causing deterioration in machinability. SOLUTION: In a sputtering device in which a thin film is formed on the surface of a substrate by sputtering particles emitted from a target as a sputtering material, an earth shield 8 provided on the side face of all the periphery of a rectangular target 5 is composed in such a manner that it is devided at the square parts of the rectangular four corners, and rectilinear four earth shield bodies 9 are combined, in the square parts of the four corners, the opposite face in the direction vertical to the adjacent part of the two earth shield bodies 9 is provided with a suitable space 13 to solve troubles caused by thermal elongation and contraction, furthermore, the opposite face of the adjacent part is formed into a rugged shape reverse viewed from the opposite side so as to mutually enter the other side viewed from the front side of the target 5, and plasma shielding effect and sputtering film shielding effect are secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a thin film on a substrate surface by using sputter particles emitted from a target which is a sputtering material.

[0002]

2. Description of the Related Art A sputtering apparatus of this kind is generally used for a wide variety of purposes, such as for forming a wiring metal or a magnetic recording material on a semiconductor surface. In such a sputtering apparatus, a ground shield is provided around the entire periphery of the rectangular target while securing an appropriate insulating space distance so that the plasma generated on the target surface is not diffused to unnecessary parts. Have been placed.

[0003] In order to secure the function of realizing the plasma blocking effect and the sputtered film blocking effect, the conventional earth shield is generally frame-shaped and integrally formed.

[0004]

However, as the size of the substrate and the size of the target are increased, it is required to increase the size of the earth shield. There is a problem that it becomes difficult and the finished dimensional accuracy after processing deteriorates.

Further, since the thermal expansion increases in proportion to the size, it is difficult to secure an appropriate insulation space distance between the target and the target, which causes a problem. In addition, there is a problem that the weight increases and the maintainability deteriorates.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a sputtering apparatus having an earth shield which does not cause deterioration in machinability, eliminates trouble due to thermal expansion, and can be easily maintained. I have.

[0007]

According to the present invention, there is provided a sputtering apparatus for forming a thin film on a substrate surface by using sputtered particles emitted from a target which is a sputtering material. Is divided at four corners of a rectangle, and is combined with four linearly-shaped ground shields.

With this configuration, the shape of one earth shield can be changed from a conventional frame shape to a bar shape.
The size of the material before processing the earth shield body is dramatically reduced, and as a result, processing becomes easier. In addition, since the finished dimensional accuracy can be easily ensured, it is possible to supply an earth shield having an inexpensive and highly reliable shape and finished accuracy. Further, since the weight of one earth shield body is reduced to about ４, the handling is simplified and the maintenance performance can be further improved.

Further, by providing an appropriate space in the vertical opposing surfaces of the adjacent portions of the two earth shields at the four corners of the earth shield, one of the earth shields can be used due to heat generated by plasma. Even if the thermal expansion occurs, it does not come into contact with the earth shield body on the other side, and the appropriate insulation space distance does not change.

[0010] When the opposing surfaces of the adjacent portions of the two earth shields adjacent to each other are formed in the opposite concavo-convex shape as viewed from the other side so as to enter each other when viewed from the front of the target, An open space is not formed from the front to the back as viewed from the front, and the plasma blocking effect and the sputtered film blocking effect can be secured.

Further, one end of the earth shield body basically maintains a stepwise cross-sectional shape up to the end, and the other end basically has a stepwise cross-sectional shape in the longitudinal direction. When notched in the corresponding shape, processing is simple and preferable, and furthermore, a plurality of steps are formed at an arbitrary step having a stepwise cross-sectional shape at a portion where one end of the earth shield body and the other end overlap, It is preferable that the other end is formed with a cutout having a shape corresponding thereto, since an open space can be prevented from being formed at the intersection of each step.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the sputtering apparatus of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a vacuum chamber, which comprises a lower chamber base 2 and an upper cathode base 3 which are hermetically united with each other, and a film forming chamber 4 is formed therein. At the lower part of the film forming chamber 4, a glass substrate 11 to be formed is attached to a substrate holder (not shown).
The substrate 11 can be moved by a substrate holder.

Above the film forming chamber 4, a flat target 5 made of a sputtering material is bonded to a backing plate 6 and fixed to a cooling plate 10 with screws (not shown). Are located in The cooling plate 10 is fixed to the cathode base body 3 via a space insulating member 7.

In such a sputtering apparatus, the film forming chamber 4 of the vacuum chamber 1 is evacuated by a vacuum pump (not shown) through a vacuum exhaust pipe and pulled into a high vacuum state. 4, a discharge gas such as an argon gas is introduced through a gas introduction pipe (not shown). In this discharge gas atmosphere, the target 5
Is applied to generate a plasma, and the target 5 is sputtered. On the substrate 11, a thin film is formed by sputtered particles ejected from the target 5.

Next, a description will be given of the earth shield 8 in the sputtering apparatus having the above-described overall configuration. An earth shield 8 is provided on the entire peripheral side surface of the rectangular target 5. The earth shield 8 is configured by arranging a total of four earth shield bodies 9, one on each side, so as to surround the target 5, and attaching them to the cathode base body 3 with bolts. An appropriate insulating space distance 12 is ensured between the earth shield 8 and the surface of the target 5 so that the plasma generated on the surface of the target 5 is not diffused to an unnecessary portion and the cathode base body 3 A function of preventing sputter particles from adhering to the surface. Each of the earth shield bodies 9 is formed in a stepwise cross-sectional shape so as to follow the cross-sectional shape of the peripheral portion of the backing plate 6 and the target 5 with the insulating space distance 12 therebetween.

Since a total of four ground shields 9 are arranged on the side surface of the rectangular target 5 to form the frame-shaped ground shield 8, the two ground shields 9 are used.
In the four corners adjacent to each other, as shown in FIG. 2, one end of the earth shield body 9 basically maintains a stepwise cross-sectional shape up to the end, and the other end has a longitudinal cross section in the longitudinal direction. The shape is cut out in a shape basically corresponding to the step-like cross-sectional shape. And because of the heat generated by the plasma,
An appropriate space 13 is ensured on a vertically opposed surface of an adjacent portion so that one of the ground shields 9 does not come into contact with the ground shield 9 on the other side even when thermally expanded. Also,
The mounting holes for the fixing bolts are small in the middle in the longitudinal direction, and the other holes are large to absorb the thermal expansion so that the earth shield body 9 thermally expands in the left-right direction uniformly in the longitudinal direction.

Further, as described above, one end of the earth shield body 9 maintains a step-shaped cross-sectional shape to its end, and the other end is cut out in a shape corresponding to the step-shaped cross-sectional shape in the longitudinal direction. As a result, the opposing surfaces of the adjacent portions of the two earth shield bodies 9 have opposite concave and convex shapes as viewed from the other side so as to enter the other side, and the two adjacent ground shield bodies 9 are adjacent to each other. In this portion, formation of an open space from the front to the back as viewed from the front of the target 5 is prevented. Thus, when viewed from the plasma generated on the surface of the target 5, the target 5 has a shape which is considered to be not divided.

Further, in FIG. 2, one end of the earth shield body 9 and the other end overlap each other with any of the steps 14 and 15 having a stepwise cross-sectional shape, and further with steps 14a and 1a.
5a is formed to form a plurality of steps, and the other end is formed with a cutout having a shape corresponding to the steps.
An open space is prevented from being formed at the intersection between the gaps 15 and 15.

Next, the operation of the earth shield body 9 obtained by dividing the earth shield 8 will be described. The earth shield 8 is divided into four parts, and one earth shield body 9 is thermally expanded almost only in its longitudinal direction, and further, at four corners, adjacent parts of the two earth shield bodies 9 Since an appropriate space 13 for absorbing thermal expansion is secured on the opposing surface of the target 5, an appropriate insulating space distance 12 secured between the target 5 and the target 5 can be maintained without change.

The adjacent portions of the two earth shields 9 are configured such that their opposing surfaces enter each other, and the spaces adjacent to each other are discontinuous when viewed from the front of the target 5. Therefore, the same plasma blocking effect and sputtered film blocking effect as in the case where the four corners are not divided can be ensured.

[0022]

According to the sputtering apparatus of the present invention,
As described above, the ground shield provided on the entire peripheral side surface of the rectangular target is divided at the four corners of the rectangular shape and is configured by combining four linearly shaped ground shield bodies. As a result, the size of the raw material before processing is dramatically reduced, and as a result, the processing is easy, the finished dimensional accuracy is easily secured, and the earth shield body is inexpensive and has a highly reliable shape and finished accuracy , And the weight of one ground shield is reduced to about one-fourth, so that the handling is simplified and the maintenance is further improved.

Also, by providing an appropriate space on the vertical opposing surface of the adjacent portion of the two earth shields at the four corners of the earth shield, one of the earth shields can be used due to heat generated by plasma. Even if the thermal expansion occurs, it does not come into contact with the earth shield on the other side, and the appropriate insulation space distance does not change, so that the occurrence of trouble due to thermal expansion and contraction can be eliminated.

Further, if the opposing surfaces of the adjacent portions of the two earth shields adjacent to each other are formed in opposite concave and convex shapes as viewed from the other side so as to enter each other when viewed from the front direction of the target, An open space is not formed from the front to the back as viewed from the front, and the plasma blocking effect and the sputtered film blocking effect can be secured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the shape of each earth shield body at a corner of the earth shield of the embodiment.

[Explanation of symbols]

 5 Target 8 Earth shield 9 Earth shield body 11 Substrate 13 Space

Continued on the front page (72) Inventor Hidetoshi Kawa 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 4K029 CA05 DC12 DC20 4M104 DD39 5D112 FA04 FB02

Claims (5)

[Claims] In a sputtering apparatus for forming a thin film on a substrate surface by sputter particles emitted from a target which is a sputtering material, an earth shield provided on the entire peripheral side surface of a rectangular target is divided at four corners of a rectangular. Characterized in that the sputtering apparatus comprises a combination of four linearly shaped earth shields. 2. At the four corners of the earth shield,
2. The sputtering apparatus according to claim 1, wherein an appropriate space is provided on a vertically opposed surface of a portion adjacent to the two earth shields. 3. An opposing surface of an adjacent portion of two mutually adjacent earth shield bodies is formed to have a concave and convex shape opposite to each other when viewed from the other side so as to enter each other when viewed from the front of the target. The sputtering device according to claim 1 or 2, wherein 4. One end of the earth shield body basically maintains a stepwise cross-sectional shape up to its end, and the other end basically has a stepwise cross-sectional shape whose longitudinal cross-sectional shape in the longitudinal direction. The sputtering device according to claim 1, wherein the sputtering device has a corresponding shape. 5. An overlapping portion of one end portion of the earth shield body with the other end portion forms a plurality of step portions at an arbitrary step portion having a stepwise cross-sectional shape, and the other end portion has a notch of a corresponding shape. The sputtering device according to claim 4, wherein a portion is formed.