JPH0313572A - Sputtering device - Google Patents

Abstract

PURPOSE:To judge the life of a target without opening a vacuum treating chamber by providing a recess on the rear of the part of a target which is most likely to be eroded, furnishing an opening in a target supporting plate opposed to the recess and detecting the lightness of the opening. CONSTITUTION:The recess 1a is provided on the rear of the part of the target 1 which is most likely to be thinned when the target is exhausted. The opening 4a is furnished in the target supporting plate 4 at the position facing the recess 1a, and vacuum-sealed by an O ring 8 and a quartz glass 9. An optical sensor is provided on the rear of the glass 9. When the target 1 is eroded to the depth of the recess 1a as sputtering proceeds, a through hole is formed in the target 1, and the opening 4a is exposed to the surface of the target 1. At this moment, the optical sensor receives plasma light, its output level is increased, hence the exhaustion of the target 1 is confirmed, and sputtering is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus, and particularly to the structure of a target and a target support plate.

[Conventional technology]

In sputtering equipment, accelerated argon ions collide with the target surface, and atoms and molecules ejected from the target surface are deposited on the processing substrate, but most of the sputtering equipment currently used for industrial purposes uses a magnetron sputtering method that focuses plasma using a magnetic field to increase sputtering speed. For this reason, the target is sputter-etched locally in areas where the magnetic field is strong, and its usage limit is determined by the most severely eroded area within the target surface, that is, the thinnest area. In other words, when the minimum thickness within the target plane becomes small, it becomes unusable and the target must be replaced.

In conventional sputtering equipment, the lifespan of a target is determined by integrating the sputtering power since the start of use of a new target and comparing that integrated power value with the integrated power value of the target usage limit set in advance. was.

[Problem to be solved by the invention]

In the conventional winter battering equipment described above, the correlation between the sputtering integrated power value and the minimum thickness of the target is investigated by using the target to the end of its life, and the sputtering integrated power value at the limit of use is input in advance. There is a need. However, since the sputter etching speed of the target differs depending on its material, when using a target for which the relationship between the sputtering integrated power value and the minimum thickness of the target is unknown, the wood lifespan can be determined by monitoring the integrated power value. become unable to do so. Therefore, in order to determine the lifespan of a target, it is necessary to open the vacuum processing chamber to the atmosphere and actually measure the erosion depth of the target using a caliper or the like each time the determination is made.

In addition, in this method, in order to bring the vacuum processing chamber to the atmosphere, high vacuum evacuation and cleaning of the target surface by pre-sputtering must be performed before the film can be formed again, which requires man-hours and time. Furthermore, this led to a decline in the operating rate. If sputtering is continued with a long target check period, there is a risk of holes forming in the target. In this case, there are problems in that the support plate of the target is also sputtered, contaminating the processing substrate and the inside of the vacuum processing chamber, or cracking the target.

On the other hand, even when using a target for which the relationship between the sputtering integrated power value and the minimum thickness of the target is known, considering the reproducibility of the relationship between the two and the error in the sub-lid integrated power value, 2 to 3 times the target is used. The life is defined as the point when a thickness margin of about 1 m remains.

As a result, targets were not used as efficiently as possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sputtering apparatus capable of determining target life without opening a vacuum processing chamber to the atmosphere.

[Means to solve the problem]

A sputtering apparatus of the present invention includes a target that generates a substance to be deposited on a processing substrate by a sputtering phenomenon and a target support plate that supports this target, in which a portion of the target is expected to be most eroded. A recess is provided on the back surface of the target supporting plate, and an opening is provided in the target support plate facing the recess.
Additionally, an optical sensor is provided to detect the brightness of this opening.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are a sectional view of the vicinity of the cathode of a sputtering apparatus according to an embodiment of the present invention, and a plan view of the target as viewed from the back side.

Reference numeral 1 denotes a target, and atoms and molecules scattered from the target adhere to the opposing processing substrate 2 to form a film. 3 is a vacuum container, 4 is a target support plate on which the target 1 is fixed and supported, and both have an insulating tongue, an insulator 5, and 0.
Ring 6a.

6b. Furthermore, a cooling water channel (not shown) is provided inside the target support plate 4, and has the function of cooling the target 1, which becomes hot during sputtering. In addition, magnets 7a, 7b,
Since the plasma is focused by the magnetic field formed by 7c,
The target is locally sputter etched as shown in FIG. 1(a).

In addition, a recess 1a is provided on the back surface of the target 1 at the part that is expected to be the thinnest when the target 1 reaches the end of its life, and its depth is equal to the remaining thickness of the target when the target is judged to have reached the end of its life. , for example, is set to 111 m.

On the other hand, the target support plate 4 is provided with an opening 4a at a position opposite to the recess 1a on the back surface of the target 1, and is vacuum-sealed by an O-ring 8 and quartz glass 9. An optical sensor 10 is provided on the back side of the quartz glass 9 to detect the brightness of the opening 4 through the quartz glass 9.

Normally, the opening 4a is closed by the target 1, so the output level of the optical sensor 11 is low. As sputtering progresses, the erosion of the target 1 progresses, and when the depth of the erosion reaches the concave portion 1a, as shown by the imaginary line (-dotted chain line), that is, when the target 1 reaches the end of its service life, a through hole is formed in the target 1. , the opening 4a is exposed on the surface side of the target. Since this instantaneous optical sensor 10 receives plasma light and its output level increases, the apparatus determines that the target 1 has reached the end of its life and stops sputtering.

In this way, the sputtering apparatus of the present invention has the optical sensor 1.
The life of the target 1 can be determined based on the output of 0.

〔Effect of the invention〕

As explained above, the present invention provides a recess on the back surface of the target, and an opening on the support plate facing the recess,
Furthermore, by providing an optical sensor for detecting the brightness of this opening, the lifespan of the target can be determined instantaneously and with high precision.

In addition, since the accuracy and reliability are superior to the conventional indirect life judgment method using integrated power values, the erosion depth of the target when the target reaches the end of its life can be set to a large value.
This has the effect of improving target use efficiency. Furthermore, since the lifespan of the target can be determined while the vacuum processing chamber is kept in a vacuum, it is possible to eliminate the downtime of the apparatus that occurs when determining the lifespan due to exposure to the atmosphere.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are a sectional view of the vicinity of the cathode of an embodiment of the present invention, and a plan view of the target as seen from the back side. DESCRIPTION OF SYMBOLS 1... Target, 1a... Recessed part, 2... Processing board, 3... Vacuum container, 4... Target support plate, 4
a... Opening of target support plate, 5... Insulator, 6a, 6b... O ring, 7a to 7C...
Magnet, 8...0 ring, 9...quartz glass,
10... Optical sensor.

Claims (1)

[Claims] In a sputtering apparatus having a target that generates a substance to be deposited on a processing substrate by a sputtering phenomenon and a target support plate that supports this target, a recess is provided on the back surface of a portion of the target that is expected to be most eroded, A sputtering apparatus characterized in that an opening is provided in the target support plate facing the recess, and an optical sensor is provided to detect the brightness of the opening.