JPH0369989B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Application Field) The present invention relates to a sputtering device provided with a pollution prevention material. (Background of the Invention) Conventionally, thin films for electrodes and diffusion barriers in integrated circuits, magnetic thin films for magnetic recording media, and thin films for liquid crystal display devices have been used.
Sputtering technology is used to form many thin films such as ITO transparent conductive films. Sputtering is a process in which a high voltage is applied between an anode and a cathode to generate a discharge, and constituent substances are ejected from a target placed on the cathode by ion bombardment, and then deposited on the opposing substrate. This is a technology that forms thin films using Currently, this type of sputtering process has been established as a mass production technology, but there is a problem that coarse particles, generally called particles, accumulate on the film formed by the CVD process, which is a similar film formation process. Closed up. Particles are clustered fine particles that are deposited on a substrate when a target is sputtered, and since these fine particles often have a diameter of several micrometers, they are deposited on the substrate. When deposited, e.g. LSI
In this case, problems such as wiring short-circuiting or, conversely, wire breakage may occur, leading to an increase in the defective rate. These particles are caused by various factors, such as those caused by the target itself and those caused by the sputtering device, and various efforts are currently being made to investigate the causes and reduce them. (Prior art and its problems) Particles caused by sputtering equipment include peeling of the sputtering thin film attached to the periphery of the substrate, the inner wall of the chamber (furnace wall), the shutter, the shield plate, etc., which scatters and accumulates on the substrate. Another major factor is that it becomes a source of pollution. In order to prevent particles caused by such re-peeling of the adhered substances, it is necessary to constantly clean the inner wall of the sputtering apparatus. It is actually very difficult to keep these inner walls clean at all times, it takes a lot of time to completely clean them, and there are some parts of the inner walls that cannot be cleaned. . To this end, we devised a pollution prevention material using disposable foils such as Al foil and electrolytic Fe foil. It was thought that it would be possible to keep the inner wall clean by attaching the foil to the inner wall in advance and removing it after sputtering. However, a fatal flaw was discovered in these disposable foils. This is because the sputtering scattered material film deposited on the installed foil was easily peeled off, and particles still occurred on the deposited film on the substrate. This disposable foil
It has been found that the peeling phenomenon occurs more prominently when the film of the scattered substance is thicker, and is more likely to occur when the product is ceramic-based such as silicide or ITO (indium-tin oxide). In order to prevent this peeling, the foil had to be replaced frequently, and the operability of sputtering deteriorated significantly. For this reason, there has been a desire for the emergence of an innovative anti-fouling material for covering inner walls. (Means for solving the problem) In order to solve the above problem, we investigated various foils as a material to prevent contamination inside the sputtering chamber, and as a result, we found that Treat electrolytic copper foil is the most suitable material for preventing contamination. , we obtained the following knowledge. That is, the present invention provides (a) a sputtering chamber contamination prevention material made of an electrolytic copper foil on which a thin layer of copper or copper oxide fine particles is formed by copper plating on the matte surface of the electrolytic copper foil; The installed sputtering equipment and
(b) The surface roughness Rz of the matte side of the electrolytic copper foil is 5 μm or more
The sputtering device of (a) and (c) above, which has a thickness of 10 μm.
The sputtering apparatus of (a) and (b) above, in which the fine particle thin layer forming surface is the sputtering scattering particle capture surface, and (d) the above (a), (b), (d) is a disposable electrolytic copper foil
c)
The present invention provides a sputtering device. (Detailed Description of the Invention) By using the electrolytic copper foil of the present invention, there is no contamination of the walls in the sputtering equipment (furnace), and the generation of particles caused by the peeling of scattered products from the inner walls is significantly reduced, which is good. It has become possible to carry out sputtering. The thin layer of fine particles formed on the matte surface of the electrolytic copper foil can be formed by an electroplating process such as US Pat. No. 3,220,897 or US Pat. No. 3,293,109. Although this treatment itself is well known, in the present invention, by using the pollution prevention material of the present invention in place of conventional foils that could only be used with Al foil or iron foil, it is possible to bring about significant effects. It became possible. A fine particle thin layer is formed on the matte surface of electrolytic copper foil (raw foil), and an example of the electroplating conditions for forming this is shown below. Aqueous copper sulfate plating bath CuSO ₄・5H ₂ O, g/(as Cu)…23 NaCl, ppm (as Cl)…32 H ₂ SO ₄ , g/…70 Glue, g/…0.75 Pure water…Ba ．． Plating conditions Current density: 60 to 100 a.sf Time: 10 to 60 seconds Bath temperature: 70 to 80〓 The matte side (matte side) of electrolytic copper foil (raw foil)
When observed with an electron microscope on the surface opposite to the contact surface (glossy surface) of a roll or the like in the manufacturing process of the foil, the matte surface exhibits a rough surface with numerous knob-like shapes (clumps and protrusions). Furthermore, when a thin layer of fine particles is formed on this surface, fine grains (nodulars) of copper or copper oxide are randomly deposited on the knob-shaped rough surface of the electrolytic copper foil (raw foil), which is similar to the electrolytic copper foil. Observed with a microscope. (Reference material: Electronic Technology, June 1985 Special Issue, 97 pages.
~105P.) The copper foil formed under the above conditions is further coated with a barrier layer of brass or zinc to provide heat resistance properties as shown in Japanese Patent Publication No. 54-6701, and further coated with copper foil. Alternatively, antirust treatment can be applied to prevent oxidation during storage. The present invention includes all electrolytic copper foils manufactured by these steps. The surface roughness of the electrolytic copper foil is preferably in the range of Rz5.0 to 10.0 μm. Due to the presence of the protrusions due to this roughness, the adhesion with the product formed by the precipitation of scattered substances is improved due to the anchor effect, and the peeling phenomenon does not occur. The material used as the contamination prevention material in the sputtering device of the present invention has a thickness of 10 μm to 100 μm.
m is suitable, and 10 to 70 μm is preferable. If it is too thin, wrinkles will easily form when it is set on the furnace wall, and wrinkles will cause peeling, so it must be avoided. If it is thick, wrinkles are less likely to occur, but it becomes difficult to operate when setting it on the furnace wall, and it is also disadvantageous in terms of cost. As mentioned above, since electrolytic copper foil is manufactured in a glue electrolytic bath, glue may adhere to the surface of the foil. Therefore, in order to prevent contamination of the inside of the sputtering apparatus due to splashes, it is preferable to perform ultrasonic cleaning using an organic solvent such as acetone or alcohol or heated ultrapure water before use. Note that vacuum heating may be performed for the purpose of drying after washing. When performing vacuum heating,
It is best to ensure that the surface protrusions do not change due to growth phenomena.
It is necessary to keep the temperature below 400℃. Next, the present invention will be explained based on examples. Example 1 Using an ITO target for transparent conductive films, various foils shown in Table 1 were attached to the inner wall of the chamber of a sputtering apparatus, and sputtering was performed.
After completing sputtering at 390W/Hr, the foil was removed. A scattered ITO film was also formed on the foil. When this film was subjected to a peel test using Scotch tape, only the electrolytic copper foil of the present invention and the electrolytic copper foil did not cause peeling of the ITO film. The test materials and results are shown in Table 1.

[Table] Example 2 Using a silicide target, an electrolytic iron foil and an electrolytic copper foil of the present invention were simultaneously set on the inner wall of a sputtering apparatus and sputtering was carried out. After sputtering, both foils should have a thickness of approx.
A 1 μm silicide film was formed. When the sample was subjected to a peel test using Scotch tape and a strong adhesive double-sided tape (No. 500), only the electrolytic copper foil of the present invention did not peel off in any of the tests. The results are shown in Table 2.

[Table] Example 3 An ITO target was set in a sputtering device, and electrolytic copper foil (both the pollution prevention material of the present invention with and without a fine particle layer formed thereon), electrolytic iron foil, pure Four types of Al foil were set at the same time and ITO sputtering was performed. Sputtering was interrupted every 100W/Hr and the condition of the sample was checked. The electrolytic copper foil on which the fine particle layer of the present invention was formed did not peel off at all even after sputtering up to 800 W/Hr, but other 3
Seed samples began to peel when sputtering was continued at 400W/Hr. Moreover, only in the foil of the present invention, no peeling was observed in the peeling test by repeated bending. (Effects of the Invention) As is clear from the above examples, the sputtering device in which the contamination prevention material of the present invention is disposed inside is more contaminant of the sputtering thin film than conventional Al foils, iron foils, etc. The generation of particles can be significantly suppressed. In addition, electrolytic copper foil has high thermal conductivity and is not charged with electricity, so it is ideal as a pollution prevention material installed in a sputtering chamber.

Claims (1)

[Claims] 1. A sputtering chamber contamination prevention material made of an electrolytic copper foil with a thin layer of copper or copper oxide fine particles formed by copper plating on the matte surface of the electrolytic copper foil is disposed inside. sputtering equipment. 2 The surface roughness Rz of the matte side of the electrolytic copper foil is 5μm
The sputtering apparatus according to claim 1, which has a thickness of 10 μm. 3. The sputtering apparatus according to claims 1 and 2, wherein the fine particle thin layer forming surface is the sputtering scattering particle capturing surface. 4. The sputtering apparatus according to claims 1 to 3, which is a disposable electrolytic copper foil.