JPH07126843A - Sputtering device - Google Patents

Abstract

PURPOSE:To provide a sputtering device having a device for detecting the life of a target. CONSTITUTION:A pair of poppet-shaped electrodes 10 insulated from each other are mounted on a shielding plate 5 of the sputtering device consisting of a target 2, a wafer stage 3 disposed to face this target 2 and the shielding plate 5 arranged between the target 2 and the wafer stage 3. These electrodes 10 are connected via a line 11 to a conductivity detector 12, which detects the point of the time when the thickness of the sputtered film deposited on the shielding plate 5 by sputtering attains a value corresponding to the thickness considered as the life of the target 2. As a result, the life of the target is exactly decided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus, and more particularly to a sputtering apparatus equipped with a device for detecting the life of a target.

[0002]

2. Description of the Related Art Conventionally, when a thin film is formed on a semiconductor device (hereinafter referred to as a wafer), high-energy particles such as ion particles are made to collide with the surface of a target so that the particles of atoms or molecules ejected from the target are removed. A so-called sputtering device for depositing on a wafer is used.

In this sputtering apparatus, the target is gradually consumed as the amount of sputtered wafers increases, the shape of the sputtering surface of the target changes, and normal film formation cannot be performed. Since there arises a problem that a material is sputtered to form a film, it is necessary to regularly replace the target.

As a means for detecting the life of the target which is consumed in this way, for example, in Japanese Unexamined Patent Publication Nos. 3-180469 and 4-168269, a material different from the material of the target is placed in a recess provided on the back surface of the target. An apparatus is disclosed that determines the life of a target by detecting specific light emitted from the material during burying or sputter etching. Further, Japanese Patent Laid-Open No. 63-83258 proposes a sputtering apparatus that can easily detect the service life of a target by obtaining the integrated power value supplied to the target from the power supplied to the target and the time. .

[0005]

However, in the above-mentioned prior art, the former Japanese Patent Laid-Open Nos. 3-180469 and 4-180469 have been proposed.
In the case of No. 168269, there is a problem in that the metal film formed immediately before the target life is detected contains a foreign substance that emits specific light, which adversely affects the film quality.

In the case of the latter Japanese Patent Laid-Open No. 63-83258, the target cannot be used as efficiently as possible because it is necessary to leave a margin for the target, and for example, Ti and reactive TiN can be used in one chamber. When the film formation is commonly used, there is a drawback in that it is difficult to properly determine the life because the accumulated electric power value is deviated. The present invention has solved the above-mentioned problems of the prior art, and an object of the present invention is to provide a sputtering apparatus capable of accurately determining the life of a target.

[0007]

The present invention comprises a target, a wafer mounting table provided facing the target, and a shield plate disposed between the target and the wafer mounting table. In a sputtering device for forming a thin film on a wafer on a mounting table, a pair of electrodes, which are provided on the shield plate and are insulated from each other and whose head is larger than the diameter of the body, are connected to the electrodes. And a continuity detector.

An insulation resistance measuring device can be used as the conduction detector.

[0009]

[Operation] According to the present invention, since a pair of electrodes whose heads insulated from each other are larger than the diameter of the body is mounted on the shield plate, the spatter deposited on the shield plate by sputtering. It is possible to detect the time when the thickness of the film reaches a value corresponding to the thickness that is considered to be the life of the target, and thus it is possible to accurately determine the life of the target.

[0010]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side sectional view showing an embodiment according to the present invention. In the figure, 1 is a chamber, 2 is a target, and 3 is a wafer mounting table on which a wafer 4 is mounted. 5 is a shield plate having a hole 5a in the center,
It has a function of preventing the sputtered material from the target 2 from directly adhering to the inner surface of the chamber 1.

Reference numeral 6 denotes a target holding table for holding the target 2, to which a sputtering power source 7 is connected. Reference numeral 8 is an introduction pipe for introducing Ar gas, and 9 is a vacuum pump for evacuating the chamber 1. 10 is a pair of mossy electrodes, 11
Is a line connected to the electrode 10, and 12 is a continuity detector. The electrode 10 is attached so as to face the periphery of the hole 5a of the shield plate 5 so as to penetrate the shield plate 5, and its shape is a mosquito shape as shown in an enlarged view in FIG. Ie its head 10
A is preferably spherical, and its diameter may be a value larger than that of the body portion 10b, and preferably 1.5 times or more the diameter of the body portion 10b. This is to prevent electrical conduction as soon as the sputtered film is formed when the diameter is made equal to that of the body portion 10b. The height h of the lower end of the head 10a of the electrode 10 is set to a value corresponding to the limit consumption thickness of the target 2 in accordance with the life of the target 2. The normal value of this height h is 30
It is set to 00 to 5000 μm.

On the other hand, the body portion 10b is fixed to the shield plate 5 through an insulator 13 such as ceramics, and the upper end of the insulator 13 is projected to the lower end of the head 10a of the electrode 10. As a result, the electrode 10 does not conduct until the film thickness of the sputtered material is deposited to the height h. The lower end portion 10c of the body portion 10b is projected on the lower surface of the shield plate 5 so as to be connected to the line 11.

When the sputtering of the wafer 4 is repeated by using the sputtering apparatus thus constructed, the wafer 4
As the number of processed wafers increases, the thin film 14 is deposited on the shield plate 5 by sputtering as shown in FIG. 3, and the film thickness gradually increases. When the film thickness (deposition height) reaches a predetermined height h which is set in advance, the two electrodes 10 are electrically connected by the thin film 14 formed by sputtering. By detecting, the life of the target 2 can be determined. Therefore, the target 2 may be exchanged when this detection signal is output.

Although the above-mentioned embodiment has been described as using the kokeshi-shaped electrode in which the diameter of the head is larger than that of the body, the present invention is not limited to this, and the head is the body. Various shapes such as an umbrella shape and a trapezoidal shape may be used as long as they are larger than the portion. Further, in the above-mentioned embodiment, the life is detected by the conduction, but in order to further improve the accuracy, it is preferable to use, for example, an insulation resistance measuring device so as to detect a rapid change point of the insulation resistance.

[0015]

As described above, according to the present invention,
By attaching a pair of kokeshi-shaped electrodes insulated from each other on the shield plate and detecting the time when the thickness of the sputtered film deposited on the shield plate by sputtering reaches a value equivalent to the target lifetime Since the life of the target is accurately determined, the reliability of the sputtering apparatus can be improved and the quality of the wafer sputter can be improved.

[Brief description of drawings]

FIG. 1A is a side sectional view showing an embodiment of the present invention, and FIG.
FIG.

FIG. 2 is an enlarged side sectional view showing an electrode used in the present invention.

FIG. 3 is a diagram for explaining the operation of the present invention.

[Explanation of symbols]

 1 chamber 2 target 3 wafer mounting table 4 wafer 5 shield plate 6 target holding table 7 sputter power supply 10 electrode 12 continuity detector 13 insulator 14 thin film by sputtering

Claims (2)

[Claims] 1. A thin film is formed on a wafer on the wafer mounting table, which comprises a target, a wafer mounting table provided facing the target, and a shield plate disposed between the target and the wafer mounting table. In the sputtering apparatus to be formed, a pair of electrodes, which are provided on the shield plate and are insulated from each other and whose head is larger than the diameter of the body, and a conduction detector connected to the electrodes are provided. A sputtering apparatus characterized by the above. 2. The sputtering apparatus according to claim 1, wherein the conduction detector is an insulation resistance measuring device.