JPH04305081A - Metallizing treatment device for ceramic material - Google Patents

Abstract

PURPOSE:To form the denser metallized film on a surface not facing a target with a bias sputtering device by disposing a magnet to curve the incident direction of charge particles near a material to be metallized. CONSTITUTION:The sputtering target 1 connected to a DC power source 2 is disposed in a vacuum chamber 5 and the ceramic material 9 to be metallized is so disposed as to nearly face this target 1 and a revolving table 6 on which the material 9 rises is connected to a high-frequency power source 4. Further, the permanent magnet 8 is disposed near the material 9 to be metallized by fixing the magnet to the revolving table 6. A sputtering gas is ionized and the material 9 is irradiated with the sputtering gaseous ions during the sputtering period. The orbit of the charge particles with which the material 9 is irradiated nearly perpendicularly is curved by the effect of the magnet 8. The denser metallized film is formed on the surface not facing the target 1 of the material 9 to be metallized having an intricate shape in this way.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for metallizing ceramic materials, which is used for metallizing ceramic materials having complex shapes such as steps and grooves.

0002

2. Description of the Related Art Sputtering methods or ion plating methods, which are classified as physical vapor deposition methods, have been used in the electronics industry for many years as means for forming thin films for electronic devices such as magnetic heads and various substrates. These physical vapor deposition methods are also used to form metallized films of ceramic materials because they allow the formation of thin films with substantially uniform thickness and high adhesion. Even with physical vapor deposition, which has such advantages, if there are steps on the surface of the material to be vapor-deposited, the amount of vapor deposited in the shadowed area from the target or other vapor deposition source may decrease, or the vapor may not be able to be deposited. There is a drawback that a shadowing phenomenon occurs.

For example, when attempting to form Al wiring for an LSI using physical vapor deposition means, the contact portion of the LSI substrate is a groove, and shadowing phenomenon may cause wire breakage. Furthermore, it is known that with the above-mentioned physical vapor deposition means, appropriate film quality may not be obtained even when the material surface is inclined with respect to the vapor deposition source. G. DIRKS and H. J. LEAMY
, Thin Solid Films, 47 (
1977) For p219, the angle of inclination of the substrate surface to be deposited is 80
When the temperature reaches 5°, the density of the deposited film becomes 5° compared to 0° (i.e., when the substrate surface is perpendicular to the normal to the surface of the evaporation source).
There have been reports that it is below 30%. Conventional countermeasures include (1) scattering of vapor deposited particles: for example, in the sputtering method, sputtering gas pressure is increased; (2) During film formation, the evaporation source or the material to be evaporated is moved periodically, and the direction in which the evaporation particles enter is constantly changed, thereby reducing the directional dependence of the evaporation particles. Methods have been used to prevent the ing phenomenon.

Recently, a bias sputtering device has been developed that connects the substrate to a high-frequency power source to ionize sputtering gas, such as Ar, and irradiates the substrate with Ar ions during the sputtering period to densify the metallized film. has been done.

[0005]

[Problem to be solved by the invention] Ceramic materials have extremely poor wettability with brazing materials such as solder on their surfaces, so when joining other materials (ceramics or metal materials), it is necessary to It is necessary to form a metallized film on the corresponding portion. In order to prevent the shadowing phenomenon, the above-mentioned method (1) or (2), which is similar to the method used to form thin films for electronic devices such as LSIs, is used to form such metallized films. For ceramic materials, the solder used to join other materials diffuses into the metallized film, forming intermetallic compounds that cause the metallized film to become brittle, and the adhesion strength of the metallized film to deteriorate significantly. There are cases. In order to prevent such diffusion of solder and the like, the metallized film must be made denser. Furthermore, since ceramic materials are usually produced as sintered bodies, the as-sintered surface is very rough, so the shadowing phenomenon described above tends to occur and the density of the metallized film tends to decrease. Therefore, it is necessary to suppress the influence of surface roughness as much as possible by polishing the surface roughness to a submicron order with a maximum surface roughness Rmax before metallization processing. However, since there is a limit to reducing the surface roughness of ceramics sufficiently, there has been a desire to develop an apparatus that can produce metallized films that are denser and have stronger bonding strength. If the above-mentioned bias sputtering apparatus is applied to such requirements, it is expected that a very dense metallized film can be formed. However, although bias sputtering equipment is very effective when creating a metallized film only on one surface facing the ceramic target,
For example, when a metallized film is simultaneously formed on the top and side surfaces of a convex object, there is a problem in that the side surfaces that do not face the target cannot be made denser. An object of the present invention is to provide a metallization processing apparatus for ceramic materials that can obtain a dense metallized film even on non-facing surfaces of a target when metallizing ceramics having a complicated shape.

[0006]

[Means for Solving the Problems] The present inventor has studied an apparatus that can irradiate charged particles by bias sputtering even to a surface of a ceramic material that does not face a target, and has arrived at the present invention. That is, the present invention is a bias sputtering apparatus in which a table on which a material to be metallized is placed is connected to a high frequency power source, and a sputtering device is provided in which a table on which a material to be metallized is placed is connected to a high frequency power source, and a material to be metallized is placed so as to be substantially opposed to a sputtering target connected to a DC power source, and a sputtering target is placed in the vicinity of the material to be metallized. This is a metallization processing apparatus for ceramic materials, characterized in that a magnet is arranged to curve the direction of incidence of charged particles.

The most distinctive feature of the present invention is that a magnet is placed near the material to be metalized to curve the direction of incidence of charged particles. For example, when Ar is used as the sputtering gas and the magnet of the present invention is not installed, charged particles (Ar ions) accelerated by supplying a high frequency power source to the table on which the material to be metallized are placed face the target of the material to be metallized. The charged particles will be irradiated almost perpendicularly to the surface facing the target, and the surface that does not face the target will hardly be irradiated with charged particles, resulting in a large difference in film quality between the surface that faces the target and the surface that does not. . On the other hand, if the magnet of the present invention is arranged, the trajectory of the charged particles that are irradiated almost perpendicularly to the surface facing the target will be bent according to Fleming's left-hand rule, and the trajectories of the charged particles will be irradiated to surfaces that do not face the target. Therefore, the metallized film on the surface not facing the target can be made denser. In addition, in the device of this invention, in order to make the surface curved by the magnet into which the charged particles are incident the entire circumference of the surface of the material to be metalized that does not face the target, the magnet itself must be rotated to adjust the incident angle of the charged particles. It is necessary to change or rotate the material to be metalized.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the configuration of an apparatus according to the present invention. The apparatus shown in FIG. 1 includes a target 1 to which a DC power supply 2 is connected, a rotating table 7 on which a substrate 9 to be metallized is placed,
A revolution table 6 connected to a high frequency power source 4 via a matching circuit 3 and a permanent magnet 8 fixed to the revolution table 6 are installed in a vacuum chamber 5. In the apparatus shown in FIG. 1, both magnetic poles of the permanent magnet 8 are installed so as to apply a magnetic field in the radial direction of the revolving table 6 to the substrate 9 to be metalized. Further, the vacuum chamber 5 is grounded, and Ar
It has a gas inlet 10 and an exhaust port 11. With this configuration, a magnetic field in the radial direction of the revolving table 1 is applied to the substrate 9 to be metalized, which rests on the rotating table 7, and the trajectory of Ar ions guided by the high frequency power source 4 is bent near the substrate to be metalized. It turns out. Furthermore, since the substrate 9 to be metalized is on the rotating table 7, Ar
The surface facing the direction in which the ions enter will always change, so that the entire circumference of the side surface of the substrate 9 to be metallized can be irradiated with Ar ions.

Here, 10×10× of aluminum nitride
Ti, Ni, Au using a 5t (mm) sintered substrate
The three layers are 0.1 μm, 1 μm, and 0.1 μm in order, respectively.
I tried metallizing it to a thickness of . In addition, in order to judge whether the metallized film is dense or not, the apparatus shown in Figure 1 is used only when forming the Ni layer, and for the Ti and Au layers, no bias from a high frequency power source is applied and no permanent magnet is installed. Ordinary sputtering was performed. Table 1
2 shows the conditions for forming the Ni layer.

0010

[Table 1]

Pb-10%S of the obtained metallized substrate
n solder was placed on the film surface, spread at 310°C in a hydrogen atmosphere, and then annealed in the air at 310°C for 1 to 30 hours to provide a sample for evaluating solder diffusivity. The adhesive surface is 2 mmφ at a position 3 mm from the top surface of the side surface of the obtained material.
Kovar pins were joined using Pb-Sn eutectic solder and a tensile test was conducted. The breaking strength of the metallized film obtained in this tensile test is shown in FIG. Further, as a comparative example, a case where the same metallization was performed under the same conditions without arranging a permanent magnet is also shown in the figure. As shown in Figure 2, the metallized film created using the apparatus of the present invention has sufficient breaking strength even after 30 hours of annealing, whereas the comparative example did not break after 30 hours of annealing. The strength is extremely low. This means that the produced Ni film was dense in the inventive example, but porous in the comparative example, so the solder diffusion rate was faster and the metallized film became more brittle. , the superiority of the device of the present invention was confirmed.

0012

[Effects of the Invention] According to the present invention, it is possible to densify the metallized film on the surface not facing the target, which was impossible with conventional bias sputtering equipment, and to prevent the metallized film from becoming brittle due to solder diffusion. It's now possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the apparatus of the present invention.

FIG. 2 is a diagram comparing the breaking strengths of metallized films obtained in inventive examples and comparative examples.

[Explanation of symbols]

1 Target 2 DC power supply 3 Matching circuit 4 High frequency power supply 5 Vacuum chamber 6. Revolution table 7. Rotating table 8 Permanent magnet 9 Substrate to be metalized 10 Ar gas inlet 11 Exhaust port

Claims (1)

[Claims] 1. A bias sputtering apparatus in which a table on which a material to be metallized is placed is connected to a high frequency power source, the material to be metallized being placed substantially opposite to a sputtering target connected to a DC power source, and a table in the vicinity of the material to be metallized being placed on the sputtering target. A metallization processing apparatus for ceramic materials, characterized in that a magnet is arranged to curve the direction of incidence of charged particles.