JPH0215631B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a target for a sputtering apparatus, and more particularly to an improvement of a target for a planar magnetron type sputtering apparatus.

(Prior art) Recently, with the progress of planar magnetron type sputtering equipment, it has become possible to apply this sputtering technology to the coating of Al alloy wiring process.
Published in Semiconductor, International, may, 1979. When performing sputtering using such a device, a large amount of power is applied to the target, so it is necessary to cool the target efficiently. For this reason, in the past, a metal film such as Ni was coated on the back side of the target body such as Al alloy.
The back side of the main body is bonded to a copper cooling flange using tin-based solder.

On the other hand, polycrystalline silicon is often used for the gate electrodes of current LSIs, but polycrystalline silicon has a high specific resistance, resulting in high sheet resistance, which is an obstacle to developing high-speed LSIs. For this reason, much research is being conducted into using metal silicide, which has a low resistivity, for gate electrodes.

By the way, methods for forming the metal silicide film include a vacuum evaporation method, a CVD method, a sputtering method, and the like. Among these methods, there is a method of depositing a metal silicide film using the planar magnetron type sputtering method described above, but as mentioned above, a large amount of electric power is input to the target body, so the target body must be cooled. There is a need. Therefore, a structure can be considered in which the back side of a metal silicide target body is coated with a metal film, similar to the Al alloy target body, and this back side is bonded to a copper cooling flange via solder. When sputtering was performed using this method, there was a problem in that cracks occurred in the target body. This is because the thermal expansion coefficients of the target body and the cooling flange, which are made of metal silicide, are different, and the two are bonded and fixed, and metal silicide does not have sticky properties like Al alloy, is hard, and is brittle. This is due to the fact that a large amount of power is applied to the target, the temperature rises slightly, and tensile stress is generated in the metal silicide target body due to the difference in the thermal expansion coefficients.

(Problems to be Solved by the Invention) The present invention was made in order to solve the above-mentioned conventional problems, and the cracks occur during sputtering in which a large amount of power is applied to the target body made of hard and brittle metal silicide. It is an object of the present invention to provide a target for a sputtering apparatus that prevents the occurrence of sputtering.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a target for use in a sputtering device, in which a metal film is provided on the back surface of a target body made of metal silicide and having a trapezoidal cross section.
The back side of the target main body is brought into direct contact with the cooling member through the metal film, and a retainer ring having an inversely tapered inner circumferential surface is fitted around the target, and the cooling member is removed from the retainer ring. The target body is supported and fixed to the cooling member by a presser ring by screwing the target body into the cooling member.

(Function) The target for sputtering equipment of the present invention is as follows:
A metal film with good thermal conductivity is coated on the back side of the target body, which is made of metal silicide and has a trapezoidal cross section.
The back side of the target body is brought into direct contact with the cooling member without intervening a solder layer, and a retaining ring whose inner circumferential side surface is inversely tapered is fitted around the target body, and the cooling is carried out from the retaining ring. The structure is such that the target body is supported and fixed to the cooling member by a presser ring by screwing the member. That is, the target main body, which has a trapezoidal cross section, is mechanically supported and fixed to the cooling member by means of screws, with the reversely tapered inner circumferential surface of the presser ring being fitted into the tapered side surface of the target main body. As a result, when the temperature of the target body rises during sputtering in which a large amount of power is input into the target body, and tensile stress is generated in the target body due to the difference in thermal expansion coefficient between the body and the cooling member,
The target main body, which has a trapezoidal cross section, moves along the reversely tapered inner circumferential surface of the holding ring, and can absorb the tensile stress applied to the main body. Therefore,
It is possible to prevent cracks from occurring in the target body made of hard and brittle metal silicide during sputtering in which a large amount of power is input.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 in the figure is a target body made of molybdenum silicide, for example, which has a trapezoidal cross section, and a Ni-based metal film 2 with a thickness of approximately 30 to 50 μm is coated on the back surface of the body 1.
is covered. To manufacture such a target body, for example, a target body 1 of molybdenum silicide is made by hot pressing, a Ni-based paste is applied to the back side of the target body 1, and the metal film 2 is sintered.
Cover. The target main body 1 has a metal film 2 on its back surface directly abutted against a cooling member, for example, a cooling flange 3 made of copper, and a presser ring whose inner circumferential side is inverted tapered and fitted around the target main body 1. 4 and a screw 5 screwed from the holding ring 4 to the cooling flange.
Note that a cavity 6 is provided within the cooling flange 3 through which cooling water flows.

Therefore, when molybdenum silicide is sputtered using the target for sputtering equipment of the present invention, a metal film 2 with good thermal conductivity is coated on the back surface of the target body 1, and the back surface side of the target 1 is coated with no solder. Direct cooling flange 3
Further, the target body 1 has an inversely tapered inner surface that fits into the tapered side surface of the target body 1 so as to absorb the tensile stress on the body 1 due to the difference in thermal expansion coefficient between the cooling flanges 3. Since it is supported and fixed to the cooling flange 3 by the holding ring 4 and the screws 5, no tensile stress is generated in the target body 1 even when power of 10 kW is applied, for example, and sputtering can be performed well without cracking. be able to.

Note that the target according to the present invention is not limited to the case where the target main body is made of molybdenum silicide as in the above embodiment, but may be formed from metal silicide such as tungsten silicide, platinum silicide, tantalum silicide, titanium silicide, etc. A similar effect can be achieved.

[Effects of the Invention] As detailed above, according to the present invention, the thermal expansion coefficient is different from that of the cooling member during sputtering,
To provide a target for a sputtering device which can prevent cracks from occurring in a target body made of hard and brittle metal silicide, and which can perform good sputtering over a long period of time.

[Brief explanation of drawings]

The drawing is a sectional view of a target for a sputtering apparatus showing an embodiment of the present invention. 1... Target body made of molybdenum silicide, 2... Ni-based metal film, 3... Copper cooling flange, 4... Holding ring, 5... Screw, 6...
cavity.

Claims (1)

[Claims] 1. In a target used in a sputtering device, a metal film is provided on the back side of a target body made of metal silicide and has a trapezoidal cross section, and the back side of the target body is brought into direct contact with a cooling member through the metal film, and A presser ring having an inversely tapered inner circumferential surface is fitted around the target, and a screw is screwed from the presser ring to the cooling member, thereby supporting and fixing the target body to the cooling member by the presser ring. A target for sputtering equipment characterized by: