JPS61227166A - Bismuth or bismuth-containing target for sputtering - Google Patents

Abstract

PURPOSE:To braze a Bi or Bi-contg. target body to a backing plate and to prevent the penetration and diffusion of the brazing filler metal to the target body by coating the target body with a metal having low solid phase meltability with Bi to a suitable thickness. CONSTITUTION:The coating layer 3 consisting of the metal having the low solid phase meltability with Bi is formed to 5-300mum thickness on the backing plate A side made of Cu of the target body 2 of the Bi or Bi-contg. target for sputtering and both are joined by a brazing layer B. The metal such as Cu, Ag, Ni, Al or Au having the low solid phase meltability with Bi and good heat conductivity and the alloy thereof are preferably formed as the above- mentioned coating layer 3 by an ion plating method, etc. The penetration and diffusion of the brazing filler metal to the target body 2 are thus prevented and the heat radiation is improved, by which the exfoliation of the target body 2 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to bismuth or bismuth-containing targets for sputtering. - "Prior art" Generally, when performing sputtering using a target, in order to release a large amount of heat generated in the target,
The target is brazed to the backing plate (copper cooling plate).

When the target is bismuth (old) or bismuth alloy (e.g. Boats%Bi 40atm%Se),
Since these are susceptible to thermal shock, low melting point brazing materials such as indium (In) and In-based metals or ji (Sn) and Sn-based metals must be used.

“9 Problems to be Solved by the Invention” As mentioned above, in the case of bismuth or bismuth-containing target materials, In and In-based metals or Sn and S
If it is bonded to the backing plate using an n-based metal brazing filler metal, the bonding can be performed without damaging the target. In the specification, a problem has arisen in that the quality of the target is impaired as a result of easy penetration and diffusion (referred to as solid phase solubility).

This invention was made in order to solve the above problems, and provides a bismuth or bismuth-containing target for sputtering that can prevent penetration and diffusion of brazing filler metal into the target and improve the heat dissipation rate. The purpose is to provide.

"Means for Solving the Problems" In order to achieve the above object, the present invention provides a material that has low solid phase solubility for bismuth or a bismuth alloy and a thermally A coating layer made of a highly conductive metal is formed to a thickness of 5 μm to 300 μm.

"Operation" According to the above configuration, penetration and diffusion of the brazing material into the target body can be prevented, and the amount of heat transferred from the target body to the backing plate is increased.
Effects such as being able to prevent peeling of the target body can be obtained.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that FIG. 1 is an enlarged sectional view of a bismuth or bismuth-containing target according to the present invention, and FIG. 2 is a plan view thereof.

As shown in FIG. 1, this bismuth or bismuth-containing target l consists of a target body 2 made of bismuth (Bi) or a bismuth alloy (for example, 60 atm% Bi and 40 atm% Se), and a backing plate A of this target body 2. It is composed of a covering layer 3 formed on the side surface. In addition, the symbol B in the figure is a brazing layer for joining the target l to the backing plate A,
Its material is In and In-based metal or Sn.
and Sn-based metals are used.

The coating layer 3 is intended to prevent the metal constituting the brazing layer B from penetrating and diffusing into the target body 2, and at the same time to increase the amount of heat transferred from the target 1 to the backing plate A, and is made of bismuth. Or copper (C
u), silver (Ag), nickel (Ni), aluminum (
It is composed of metals such as Al1), gold (Au), and alloys thereof. The thickness of this coating layer 3 is determined according to the sputtering output like the conventional target, and the layer thickness is set to 5 to 300 μm. This is because if the layer thickness is made thinner than 5 μm, it may become impossible to prevent the brazing filler metal from penetrating and diffusing into the target body 2. On the other hand, if the layer thickness is made thicker than 300 μm, for example, the sputtering power may be reduced to 5 W. /cm" or more, Targera 2
This is because the temperature of the product may rise, making it impossible to put it into practical use. Note that the coating layer 3 can be formed by ion blating, vapor deposition, sputtering, plating, or the like.

Therefore, in the above-mentioned bismuth or bismuth-containing target 1, penetration and diffusion of the metal constituting the brazing layer B into the target body 2 can be prevented by the coating layer 3, and this coating layer 3 has a heat transfer property. Since it is a metal with high heat resistance, it is possible to increase the amount of heat transferred from the target body 2 to the backing plate A.

"Experimental Example" Next, an experimental example conducted to confirm the effect of bismuth or bismuth-containing target according to the present invention will be shown.

In this experiment, the presence or absence of peeling of bismuth or a bismuth-containing target from a backing plate and penetration and diffusion of brazing material into the target body during sputtering was investigated. Note that copper was used as the metal constituting the coating layer, and the bismuth target of the present invention was manufactured in the following manner.

First, a bismuth target body (203φ x 5t) and an oxygen-free steel target (φ203X 5t) were placed facing each other in a sputtering device with a distance of 50 mm, and the vacuum evacuation (
After applying a neutralizing voltage (-600V) to the bismuth target body at 5X 1G-'Torr and performing etching treatment for 5 minutes, the bismuth target was etched under an argon gas atmosphere (5X 1G-'Torr).
-3 Torr), 1255 V was applied to the oxygen-free copper target, and 1100 V was applied to the bismuth target body, and while cleaning the surface of the bismuth target, the surface was coated with oxygen-free steel. The bismuth target manufactured in this way is attached to a copper backing plate (250φx
10 t) was brazed using In-8n alloy as a brazing material.

Then, a coating layer was formed on the bismuth-containing target (203 φ x 5 t) shown in the table in the same manner, and then it was brazed to a copper backing plate (250 φ x 10 t).

The results of the experiment are as follows.

"Effects of the Invention" As explained above, according to the bismuth or bismuth-containing target for sputtering of the present invention, the joint surface of the target body to the backing plate has low solid phase solubility with bismuth or bismuth alloy, and Since it has a coating layer made of highly conductive metal, it can prevent penetration and diffusion of the brazing material into the target body, and it also increases the amount of heat transferred from the target body to the backing plate. Effects such as being able to prevent the main body from peeling can be obtained.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show one embodiment of the present invention.
The figure is an enlarged cross-sectional view, and FIG. 2 is a plan view thereof. l...Bismuth or bismuth-containing target, 2...Target body, 3...Coating layer, A...Backing plate, B... Wax layer.

Claims (1)

[Claims] A sputtering bismuth or bismuth-containing target used by being brazed to a backing plate, the joint surface to the backing plate having:
1. A bismuth or bismuth-containing target for sputtering, characterized in that a coating layer made of a metal with low solid phase solubility for bismuth is formed to a thickness of 5 μm to 300 μm.