DE69811446T4 - Metallic material or film with a fluorinated surface and fluorination process - Google Patents

Description

BACKGROUND THE INVENTION

1. area the invention

The present invention relates on a metal material or a metal layer with a fluorinated Surface layer and a fluorination process of the metal material or layer. In particular, the present invention provides fluorinated metal ready on its surface a thick layer of fluoride significantly increases the corrosion resistance. The Metal can be in any form that has the ability to cover the fluoride layer to train on it. The metal can be a monolithic material or a monolithic layer formed on the substrate is.

In particular, with the technology according to the invention intends that the metal material or layer in a production plant for Semiconductor devices and the like are used to be extremely advantageous Corrosion performance against halogen-based corrosive gases such as Realize gases based on chlorine, fluorine or bromine.

2. Description of the related State of the art

Halogen-based, reactive and highly corrosive special gases such as hydrogen chloride (HCl), boron trichloride (BCl ₃ ), fluorine (F ₂ ), nitrogen trifluoride (NF ₃ ), chlorine trifluoride (ClF ₃ ) and hydrogen bromide (HBr) are used in the semiconductor manufacturing process. These gases are easily hydrolyzed by the presence of water in the environment, thereby producing hydrochloric acid, hydrofluoric acid, hydrobromic acid and the like. The metal building material or the metal layer of a valve, a coupling, piping, a reaction chamber and the like. Like. For processing these gases corrodes easily and problems arise.

In addition, these become corrosive Gases converted into plasma or decomposed by heat. They crumble become active atom types and become the etching of the oxide or metal layer used, or are also used for dry cleaning of the reaction chamber used. Recently, the production of super ULSIs increased and the manufacturing process of liquid crystals the amount of such used gases suddenly. Highest purity and corrosion performance for the Plant materials like the surface of a reaction chamber essential.

Since fluorine gas with inert gas (Krypton, Neon, argon) mixed and vibrated in the field of an excimer laser brought is an extremely strict one Corrosion performance against the fluorine radicals for the material surface System required.

Electrolytically polished stainless steel SUS 316L is said to solve the problems described above and is for usually also used. Such stainless steel is heat treated at 250 ° C before use subjected. Still fulfilled the corrosion resistance of stainless steel the requirements are not satisfactory.

Various nickel-based alloys were therefore used at high temperature with halogen gas such as gaseous hydrochloric acid.

Nonetheless, there remained several in this regard Problems unresolved.

First is the metal material itself expensive. The formability of the metal material into parts of one Facility is bad. this leads to finally to a significant increase in the cost of the system. Furthermore becomes the corrosion resistance only achieved through a limited composition. For example Hastelloy-C (Ni-Cr-Mo-W alloy) has an extremely improved corrosion resistance against oxidizing acid, and also has improved corrosion resistance even against reducing acid like Hydrochloric acid, when used at room temperature. Hastelloy-C also has one noticeable resistance to Pitting corrosion and crevice corrosion. However, it should be noted that there the corrosion resistance by Hastelloy-C against the aforementioned fluorine gases and fluorine radicals is bad, Hastelloy-C cannot be used.

So far there has been a lot of research with regard to the passivation technology when using fluorine gas operated. It is known that a passivation layer in the Magnitude of angstrom units on the metal surface of nickel is formed to produce the corrosion resistance function.

In addition, Japanese Unexamined Patent Publication (kokai) No. 2-263972 relates to the invention entitled "Metallic Materials with Fluorinated Passivation Film Formed Thereon and Apparatus with the Use of such Metallic Materials" The publication discloses the metal material or the metal layer on which the passivation layer is formed and an apparatus in which the metal material and the metal coating are used tion layer formed by means of fluorine gas on the metal, which is selected from at least one of the metals nickel, nickel alloy, aluminum, aluminum alloy, copper, copper alloy and chromium. The corrosion resistance disclosed is of improved quality. However, the layer formed is 1000 to 3000 angstroms thick and thus ultra-thin. The surface condition of the aluminum, stainless steel, copper and nickel plates to be fluorinated is a polished surface in this publication.

In addition, the unchecked Japanese refers Patent publication (kokai) No. 2-175855 on a metal material or a metal layer, on which the fluorinated passivation layer is formed, and a device in which the metal material and the metal layer is used. The publication discloses a method of mixing on the surface of stainless steel Form fluoride layer from iron and chromium fluoride. A fluorinated one Passivation layer in the order of magnitude of less than a micron in thickness, as well as the material with such Layer are revealed. An improved corrosion resistance is disclosed. The thickness of the layer formed is 4000 angstrom and is ultra thin. Furthermore polished SUS316L sheet is subjected to fluorination.

Because the fluorinated passivation layers, those trained in the above publications about 4000 angstroms or less thick, they are easily made by material defects, Friction and Like. Removed. It is therefore difficult to say whether the layers from the point of view of durability and longevity forth as material for Manufacturing systems of semiconductor devices are suitable.

The present invention aims to achieve this starting to solve the problems with which the above prior art had to struggle. The conventional Passivation techniques are characterized in that the material surface is characterized by Polishing and Like. Is cleaned and then fluorinated to passivate them. It was discovered that when the surface is oxidized to it passivate, and afterwards it is fluorinated, not just the passivated one and oxidized surface more surprising Way of fluorination nothing opposes, but also quite a thick fluorinated layer can be formed.

The patent publication EP 0 460 701 A relates to a method of forming a corrosion-resistant protective coating on aluminum substrate, which is formed by contacting an aluminum oxide layer on an aluminum substrate at a higher temperature with one or more fluorine-containing gases.

SUMMARY THE INVENTION

It is a task of the present Invention, a fluorinated metal with a thick, stable and excellent provide durable fluoride layer.

It is also an object of the present Invention to provide a metal fluorination process that form a thick, stable and extremely durable fluoride layer can.

The present invention is through the requirements 1 to 6 defines and refers to a fluorinated metal and a metal fluorination process. Claims 1 to 3 relate to a fluorinated metal with a fluorinated layer in which at least selected a metal from the group which is made of aluminum, nickel, copper and silver. she will formed by either a surface of a monolithic metal or a surface a thin metal layer formed on a monolithic material is forcibly oxidized; and then fluorinated the positively oxidized surface is around 1 μm or to get more fluorinated layer thickness. This fluorinated Layer consists of a first layer, which consists essentially of a fluoride of the metal, and a second layer of the metal that lies under the first layer and into the fluorine is diffused.

Claims 4 to 6 relate to a metal fluorination process comprising the following steps: Forcibly oxidize either a surface of a monolithic metal or a surface a thin one Metal layer on a monololithic material by an oxidation material, in which at least one metal is selected from the group, which consists of aluminum, nickel, copper and silver; and the resulting positively oxidized layer in contact with a fluorination gas bring to form a fluorinated layer that has a thickness of 1 μm or more. The metal is aluminum, with the fluorinated layer consists of a first layer, which essentially consists of a Aluminum fluoride, and a second layer from the monolithic aluminum, which lies under the first layer, and into which fluorine has diffused.

The present invention is described in following in detail described.

DESCRIPTION OF THE EMBODIMENTS THE INVENTION

The metal fluorinated in the present invention reacts with fluorine to form a stable fluoride, and nickel, copper, silver and aluminum are selected because their corrosion resistance is greatly enhanced by fluorination. Iron is excluded in the present invention because the iron fluoride formed decomposes and dissolves due to atmospheric moisture. In a moist environment corrosion (exposure to air) is therefore favored. So there is a danger that a practical problem arises.

The metal can be an alloy which contains nickel and Al, Cu and / or Ag.

In addition, according to the present Invention to be fluorinated metal layer by electrolytic Electroplating, autocatalytic coating, physical vapor deposition (PVD) u. Like manufactured layer of nickel, silver or aluminum or an alloy containing at least one of them.

As electrolytic electroplating will Ni plating, Ni-Cu plating, Ni-W electroplating and Like mentioned. Ni-P, Ni-B, Ni-P-W, Ni-P-B coating is used as the autocatalytic coating u. Like called. additionally sputtering of Ni or its alloy is mentioned as PVD.

Different materials are considered Called substrate to form a layer. This includes various Metal materials such as stainless steel, aluminum alloy, steel and the like, sintered metal, ceramics, engineering plastics. These materials become known surface treatments before the formation of the metal layer such as degreasing, pickling, polishing and blasting.

In the following description, however Before the examples, the metal (alloy) material and the metal (alloy) layer abbreviated as "metal". In In the present invention, the metal surface is first oxidized and the metal oxide layer is then reacted with fluorine. According to the natural Oxidation is the thickness of the oxide layer from a few tens to a maximum of a few hundred angstroms. In addition are the metals on which in the case of natural oxidation a strong Oxide can be formed on the specified metals such as Aluminum limited. The term "natural oxidation is in the GLOSSARY OF TECHNICAL TERMS IN JAPANESE INDUSTRIAL STANDARDS, fourth edition (p. 729) defines and means the oxidation reaction, the in air without artificial Acceleration expires. The natural oxidation layer aluminum materials are well known (see Fundamentals and Industrial Techniques of Aluminum Materials (in Japanese), released on May 1, 1985, page 186.)

The forced oxidation process, the used in the present invention will be described below in detail described. If the fluorination is carried out after the forced oxidation, the substitution reaction of oxygen and fluorine takes place, to form the fluorinated layer. The thickness of the fluorinated layer therefore increases in proportion to the thickness of the positively oxidized layer to and is up to several tens of μm. But if the positively oxidized layer becomes extremely thick, it is yours Adhesion to the substrate reduced. The thickness of the layer seems to 10 μm to be limited. By adjusting the thickness of the oxide layer that is on the surface forms, is controlled, the thickness of the fluoride that is on the metal surface forms, are designed thicker than that by the so-called Passivation is obtained. Aluminum alloys, copper, nickel or its alloys have an affinity for oxygen and therefore a natural forms quickly Oxide layer on the surface in the atmosphere. This natural Oxide layer has an extremely dense structure and is also chemical stable.

Due to the existing oxide layer there is therefore an oxygen diffusion into the interior at normal temperature of the metal prevented. Even if they are over a long period of time the atmosphere is exposed The natural Oxide layer the ultra thin Thickness of only a few tens to a hundred angstroms. It is therefore necessary the oxide layer thickens by means of the so-called forced oxidation do. In the present invention, a workpiece with a natural Oxide layer is not directly fluorinated, but only positively oxidized and then fluorinated. The thickness of the positively oxidized layer is greater than that of natural Oxide layer and is preferably 1000 angstroms or more.

Wear resistance, corrosion resistance and durability of the fluoride layer thus formed are in improved to such a degree that they are satisfactory in practice can be used.

The fluoride layer is in the further Meaning a layer that consists essentially of fluoride. fluorination has an essential meaning here. And it is not necessary that 100% of the metal has to be replaced by fluoride. The However, oxygen is preferred to a degree by fluorine which is lower than the detection limit of oxygen. The metal does not necessarily have to be uniformly fluorinated. Instead the fluorinated layer may be unevenly thick, and the fluoride region and the fluorine diffusion area be mixed.

Will the fluorination after the forced oxidation carried out, will not just be the Oxidation layer replaced by fluorine, but to form fluoride Fluorine also diffuses into the metal mass, with the result that a thick fluorinated layer can be formed. In this Case, the fluorinated layer consists of the first layer, the consists essentially of metallic fluoride, and a second Layer that lies below the first layer and diffuses into the fluorine is.

The so-called gas phase oxidation is a means of causing forced oxidation. In this case it is oxygen or prefer a gas mixture thereof with neutral or inert gas. additionally are also nitrous oxide, nitrogen dioxide, ozone or a mixture of these to be preferred with neutral or intergas. In these cases the gases are brought into contact with the metal at high temperature.

Liquid phase oxidation can be as further funds for called the forced oxidation. This can be done by immersion into a solution like nitric acid and hydrogen peroxide water can be carried out.

In addition, the metal material to form an oxide layer on its surface using of an electrolyte such as alkali are anodized. In this The case is that the oxygen that forms on the anode is a means of Forced oxidation.

It is in the case of aluminum alloys widely known to have an oxide layer that is a few microns up is a few tens of micrometers, on the surface of aluminum alloys through the so-called anodizing process (anodic Oxidation treatment) can be formed. It became practical implemented and can therefore be used.

As described below can the methods of forced oxidation depending on the conditions such as thickness the oxidation layer and metal type can be combined.

The gases that are for use for the Suitable for fluorination are 100% gases such as fluorine, chlorine trifluoride and nitrogen trifluoride, which are caused by inert gases such as nitrogen, Helium, argon and the like. Diluted gases or the like Plasma gases from fluorine or the like. Fluorination is a manufacturing process for one Fluorine diffusion layer and a fluoride layer by the gases in contact with the oxidation layer brought, which are formed on the surface layer of the metal Has.

The following implementation is specific possible. Namely, the metal as described above is in one Normal pressure working gas phase flow reaction furnace introduced. While the oxidizing gas flows the reaction furnace is heated to a predetermined temperature and held thereon for a predetermined time. The oven will then filled with fluorination gas at a predetermined temperature. The Reaction takes place for a predetermined time to fluorinate the surface. In this case, the metal is placed in the furnace before it will, as usual degreased and dried, and then the forced oxidation takes place instead of. The purity of the subsequently oxidized layer is therefore higher and there are no defects in the layer. Because a thin natural oxide layer of some ten angstroms that on the metal surface What remains, together with the mass, is the thin natural oxide layer must not be removed before forced oxidation.

In addition, the temperature of a reaction furnace is for the forced oxidation of nickel and copper usually 200 ° C to 600 ° C, in particular preferably 300 ° C up to 500 ° C.

The response time is usually 1 Hour to 48 hours, particularly preferably 3 to 24 hours. Aluminum is preferably anodized.

The fluorination temperature is usually 100 ° C to 700 ° C, especially preferably 150 ° C up to 500 ° C at normal pressure. additionally is the response time for usually 1 to 48 hours, particularly preferably 3 to 24 hours. Under the preferred temperature and time becomes the oxygen of the positively oxidized Layer not adequately replaced by fluorine and beyond the diffusion of fluorine from the top is not satisfactory. On the other hand, if the temperature and time limits are exceeded, the fluorine reaction is so abrupt that cracks appear in the resulting Form a layer.

The present invention is made with Reference to the examples in more detail described, in which the electrolytically Ni-coated and the autocatalytic Ni-coated layer is fluorinated. The present invention is by no means by the examples described below limited.

SHORT DESCRIPTION THE DRAWINGS

1 Fig. 12 is a graph showing the measurement results of XPS spectra of Example 4.

2 Fig. 12 is a graph showing the analysis results of Manufacturing Example 1 by the XDF thin film method.

3 Fig. 12 is a graph showing the analysis results of Manufacturing Example 2 by the XDF thin film method.

4 Fig. 12 is a diagram showing the analysis results of Manufacturing Example 3 by the XDF thin film method.

5 Fig. 11 is a diagram showing the analysis results of Example 2 by the XDF thin film method.

6 Fig. 12 is a graph showing the analysis results of Example 4 by the XDF thin film method.

7 Fig. 12 is a graph showing the analysis results of Example 6 by the XDF thin film method.

8th Fig. 10 is a graph showing the analysis results of the surface composition of Example 3 by AES.

9 Fig. 12 is a graph showing the results of analysis of the fluorination thickness of the layer of Example 4 by AES.

10 Fig. 12 is a graph showing the analysis results of the samples of Comparative Example 1 according to AES.

11 is a graphical representation showing the measurement results of the natural oxidation layer and shows the gas phase oxidation layer on the Al alloy material by AES.

12 is a graphical representation of the measurement results of the natural oxidation layer and the gas phase oxidation layer on the Cu metal.

13 Fig. 11 is a graph showing the measurement results of the gas phase oxidation layer and the liquid phase oxidation layer on a NiP layer by AES.

Examples the surface treatment

Production Example 1 (Layer of electrolytic nickel coating)

The coating was carried out using commercially available shiny nickel coating reagents from the so-called Watt bath, which mainly consists of NiSO ₄ (nickel sulfate), NiCl ₂ (nickel chloride), H ₃ BO ₃ (boric acid), and brighteners. Stainless steel (SUS 316L) was previously subjected to a surface treatment by pickling. Then, a layer was formed by supplying a current with a current density of 1 A / dm ^{2 for} a predetermined time.

Production Example 2 (Layer of autocatalytic nickel coating)

That acid chemical nickel plating, which is referred to as so-called chemical coating then practically performed. Reagents based on the reduction with phosphoric (I) acid are available in the stores. The reagents used in the present manufacturing process were commercially available Reagent for chemical nickel plating, using dimethylamine borane as a reducing agent and a commercially available chemical reagent Nickel plating, with emphasis on corrosion resistance is placed, so the nickel-phosphor coating (Ni-P alloy coating).

These reagents consisted of 25 g / l NiSO ₄ (nickel sulfate) as the main component, 20 g / l NaHPO ₂ (sodium phosphinate) as a reducing agent, a complexing agent, a stabilizer and a brightener.

As in Production Example 1 the stainless steel plates first a surface treatment subjected, then immersed in an electrolytic solution bath, the on heated to a temperature of 90 ° to cause a response for a period of time and thereby form a layer.

Production Example 3

(Layer of autocatalytic Nickel alloy coating)

The reagent used was a commercially available chemical alkaline coating which emphasizes the wear resistance and the corrosion resistance after the heat treatment, and which is carried out in a nickel-phosphorus-tungsten bath (Ni-PW bath). This reagent consisted of 15 g / l NiSO ₄ (nickel sulfate) and Na ₂ WO ₃ (sodium tungstate), ie the metal component, 20 g / l NaHPO ₂ (sodium phosphinate) as a reducing agent, a complexing agent, a stabilizer and a brightener.

The stainless steel plates were initially like in the previously described examples of a predetermined surface preparation subjected to then in a container immersed in an electrolytic bath heated to a temperature of 85 ° C to cause a response for a predetermined time and thus form a layer.

Production Example 4

It was used as an example of the so-called A5083 Aluminum alloy used, and its surface was mirror polished. Then the A5083 was exposed to air for 30 days, so one thorough natural oxide layer on its surface let develop. In this way samples were provided.

Production Example 5

The so-called C1100P copper material was used as an example of a Cu alloy is used and its surface is highly polished. The C1100P was then exposed to air for 30 days to give a thorough one natural To create oxide layer. In this way samples were provided.

example 1

Samples made by the method described in Preparation Example 1 were placed in a gas phase flow reaction furnace operating under normal pressure. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure to remove the absorbed liquid and the like. To drive out. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at that level for 12 hours to subject the metal surface to forced oxidation. The temperature was then lowered and the oxygen gas was replaced by nitrogen gas at the same time. When the temperature dropped to 400 ° C, 20% F ₂ gas (diluted with nitrogen) was added to replace the nitrogen. After the replacement was complete, surface fluorination was carried out for 24 hours. After a predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 2

Rehearse; which had been prepared by the method described in Manufacturing Method 1 were placed in a gas phase flow reaction furnace operating under normal pressure. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure to remove the absorbed liquid and the like. Like drive out. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at that level for 12 hours to subject the metal surface to forced oxidation. The gas was then exchanged with nitrogen. At the exchange temperature, 20% F ₂ gas (diluted with nitrogen) was supplied to replace the nitrogen gas. After complete replacement, surface fluorination was carried out by maintaining conditions for 12 hours. After the predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 3

Samples made by the method described in Manufacturing Method 2 were placed in a normal gas phase flow reaction furnace. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at 500 ° C for 12 hours to subject the metal surface to forced oxidation. The gas was then exchanged with nitrogen while the temperature was lowered. When the temperature dropped to 300 ° C, 20% F ₂ gas (diluted with nitrogen) was supplied to replace the nitrogen gas. After complete replacement, surface fluorination was carried out by maintaining conditions for 12 hours. After a predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 4

Rehearse; which had been prepared by the method described in Manufacturing Method 2 were placed in a gas phase flow reaction furnace operating under normal pressure. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at 500 ° C for 12 hours to subject the metal surface to forced oxidation. The gas was then exchanged with nitrogen. At the exchange temperature, 20% F ₂ gas (diluted with nitrogen) was supplied to replace the nitrogen gas. After complete replacement, surface fluorination was carried out by maintaining conditions for 12 hours. After the predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 5

Samples made by the method described in Manufacturing Method 3 were placed in a normal gas phase flow reaction furnace. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at 500 ° C for 12 hours to subject the metal surface to forced oxidation. Thereafter, the temperature was lowered while the oxygen gas was replaced with nitrogen gas. When the temperature dropped to 300 ° C, 20% F ₂ gas (diluted with nitrogen) was supplied to replace the nitrogen gas. After complete replacement, surface fluorination was carried out by maintaining 300 ° C for 12 hours. After a predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 6

Samples made by the method described in Manufacturing Method 3 were placed in a normal gas phase flow reaction furnace. These samples were pretreated by heat treatment at 200 ° C for 1 hour under reduced pressure. Then the temperature was raised to 500 ° C and at the same time oxygen gas (99.999%) was supplied. The temperature was then held at 500 ° C for 12 hours to subject the metal surface to forced oxidation. The gas was then exchanged with nitrogen. At the exchange temperature, 20% F ₂ gas (diluted with nitrogen) was supplied to replace the nitrogen gas. After complete replacement, surface fluorination was carried out by maintaining the same temperature for 12 hours. After a predetermined time, the fluorine gas was replaced with nitrogen gas. After maintaining the temperature at this level for 1 hour, it was lowered.

Example 7

On A5083, which is an example of the so-called Was aluminum alloy, the surface was mirror polished. Samples with the highly polished surface were in a normal pressure introduced working gas phase flow reaction furnace. This Samples were reduced by heat treatment at 200 ° C for 1 hour Pretreated print. Then the temperature was raised to 500 ° C and simultaneously Oxygen gas (99.999%) supplied. The metal surface was then forced oxidized by maintaining the temperature for 8 hours followed by nitrogen gas exchange and then lowering the temperature. In this way samples were provided.

Example 8

At C1100, which is an example of the so-called Was copper alloy, the surface was mirror polished. Samples with the highly polished surface were in a normal pressure introduced working gas phase flow reaction furnace. This Samples were reduced by heat treatment at 200 ° C for 1 hour Pretreated print. Then the temperature was raised to 500 ° C and simultaneously Oxygen gas (99.999%) supplied. The metal surface was then forced oxidized by maintaining the temperature for 8 hours followed by nitrogen gas exchange and then lowering the temperature. In this way samples were provided.

Example 9

The one with the procedure of the manufacturing example 2 samples prepared were immersed in a 5% aqueous nitric acid solution for 10 minutes, their temperature to 50 ° C had been raised. The sample was also thoroughly tested washed in pure water and then as she was in the pure for 8 hours Leave water to the surface to oxidize. Then this sample was placed in a working under normal pressure Gas phase flow reaction furnace introduced. The nitrogen gas was introduced to the oven to replace the oxygen gas. After the exchange was under reduced Pressure at 200 ° C for 1 hour the heat pretreatment was carried out. The temperature was lowered immediately after the heat treatment.

Comparative Example 1

The sample prepared by the method of Production Example 3 was placed in a gas phase flow reaction furnace operating under normal pressure. Then the heat pretreatment was carried out at 200 ° C for 1 hour. Then the temperature was raised. When the furnace temperature reached 400 ° C, 20% F ₂ gas (diluted with nitrogen) was supplied, this state was maintained for 6 hours, and thus the fluorination of the metal material was carried out. This is widely known as the passivation process of nickel materials. Thereafter, nitrogen gas was supplied to make the fluorine gas put. After maintaining the temperature at this level for 1 hour, it was lowered.

Coating thickness measurement results

The analysis results of the sample of Example 4 by XPS (photoelectron spectroscopy with X-ray excitation) are in 1 shown. Four elements were detected on the surface, namely Ni, F, O and C. Since the tips of Ni, in contrast to those of the oxide, shift strongly towards the higher energy side, the binding of Ni with F, which are an electron donor pair, can be predicted , In addition, the two elements C and O were removed by argon ion sputtering for a few minutes and then could no longer be detected. It is therefore confirmed that the two elements C and O result from moisture and contaminants adsorbed on the surface. Even when the etching by argon ion sputtering was carried out for 100 minutes, there was no change in the detection pattern. The layer thickness of the fluorinated layer was considered to be the thickness at which the fluorine atoms could be detected by the aforementioned argon sputtering. However, a similar measurement was previously carried out with respect to the oxygen detection thickness of an SiO ₂ thin film, the thickness of which was already known. The sputtering rate was 115 angstroms per minute (hereinafter referred to as “SiO ₂ correction”). As a result, it was found that the thickness of the fluorinated layer was up to 1.2 μm and above.

The X-ray diffractometric analysis by a thin film method was carried out with respect to the samples of the production examples 1, 2, 3 and examples 2, 4 and 6. The results are shown as "SiO ₂ correction". As a result, it was found that the thickness of the fluorinated layer was up to 1.2 μm and above.

The X-ray diffractometric analysis by a thin film method was carried out with respect to the samples of the production examples 1, 2, 3 and examples 2, 4 and 6. The results are in the 2 . 3 . 4 . 5 . 6 and 7 shown.

In 2 only the tips of the metal Ni are detected.

In the 3 and 4 broad peaks of Ni-P and Ni-PW were obtained, whereby the non-crystalline state can be confirmed. When the heat treatment was additionally carried out under nitrogen gas atmosphere at 400 ° C for 3 hours, it was confirmed that crystallized Ni and Ni ₃ P had formed.

The results of fluorinated preparation examples 2, 4 and 6 are shown in FIGS 5 . 6 and 7 shown. Out 5 confirms that nickel fluoride (NiF ₂ ) had formed on the surface of the nickel metal.

In 6 the diffraction peaks of Ni and Ni ₃ P appear weak, and the salient and most of the other peaks are NiF ₂ . These peaks are recorded at high intensity. The measurement by a thin film method was carried out at an X-ray incident angle (θ) of 1 °. Theoretically, the thickness examined corresponds to 2.1 μm from the surface. The fluoride layer is therefore on the surface of the autocatalytic nickel coating in the order of μm.

In 7 the diffraction peaks of Ni and Ni ₃ P are only very weakly recorded, and the salient and most of the other peaks are also NiF ₂ . These peaks are recorded at high intensity. This result is almost the same as that of Example 6. There is not much difference in the surface condition of Example 6.

In 8th the examination results of the sample according to Example 3 are shown by AES (Auger electron spectroscopy). Four elements, namely Ni, F, O and C, were detected on the surface. The elemental composition on the top surface layer is shown in Table 1. C and O, which would have resulted from moisture and contaminants on the surface, were removed by argon ion sputtering for a few minutes and were no longer detected. The atomic proportion of Ni and F is approximately 1: 2. From this result, together with the results of the X-ray diffraction described above, it could be confirmed that nickel fluoride (NiF ₂ ) had formed on the top surface layer. If the argon ion sputtering was continued until the fluorine was no longer detectable, the detection intensity of the fluorine began to decrease after approx. 90 minutes and became almost no longer detectable after approx. 150 minutes. From this and also from the etching rate of 115 angstroms / minute (SiO ₂ correction) by argon ion sputtering, the thickness of the fluorinated layer including the fluorine diffusion layer was set at 1.7 μm. It was thus possible to confirm that the thickness of the fluorinated layer is on the order of μm.

Table 1 Surface composition of Example 3 according to AES

In 9 the AES test results of the samples of Example 4 are shown. Four elements, namely Ni, F, O and C, were detected on the surface as in Example 3 described above. The elemental composition on the top surface is shown in Table 2. C and O, which would have resulted from moisture and contaminants on the surface, were removed by argon ion sputtering for a few minutes and were no longer detected. The atomic proportion of Ni and F is approximately 1: 2. From this result, together with the results of the X-ray diffraction described above, it could be confirmed that nickel fluoride (NiF ₂ ) had formed on the top surface layer. When the argon ion sputtering was continued for another 280 minutes, there was no large change in the surface state. From this and also from the etching rate by argon ion sputtering, the thickness of the fluorinated layer (SiO ₂ ) was set to 3.2 μm or more. It was thus possible to confirm that the thickness of the fluorinated layer is on the order of μm.

Table 2 Surface composition of Example 3 according to AES

In 10 the AES test results of samples of Comparative Example 1 are shown. Four elements, namely Ni, F, O and C, were detected on the surface. The elemental composition on the top surface layer is shown in Table 3. C and O, which would have resulted from moisture and contaminants on the surface, were removed by argon ion sputtering for one minute and were no longer detected. The atomic proportion of Ni and F is approximately 1: 2. However, the detection intensity of the fluorine decreased after a few minutes from the start of the sputtering, and fluorine was not detected at about 20 minutes. From this and also from the etching rate of 115 angstroms / minute (SiO ₂ correction) by argon ion sputtering, the thickness of the fluorinated layer was set at 2300 angstroms. It could thus be confirmed that the thickness of the fluorinated layer is in the order of sub-μm.

Table 3 Surface composition of Example 1 according to AES

Effect example 1

The corrosion resistance different materials have been tested. The results are in Table 4 shown. The evaluation of the corrosion resistance expressed are characterized by the weight loss of the different materials, at room temperature (25 ° C) 24 hours in water 35% hydrochloric acid solution immersed were. The surface treated Samples used in Preparation Examples 2 and 3 as comparative materials had been formed, and the samples of Examples 3, 4, 5 and 6 were used. When removed after 24 hours, there was weight loss measured. As a result of a comparison it turned out that the weight loss of Example 5 was least.

With a view to change in appearance occurred on the edges and other parts of the samples of Examples 3 and 5 pitting corrosion on. Other than that, the corrosion weight loss was each example less than that of the autocatalytic nickel coating of Manufacturing Examples 3 and 5. This fact revealed that the samples on their surface fluoride forms, a greatly improved corrosion resistance exhibit.

Table 4 Test result of resistance to hydrochloric acid solution

Test condition - 35% hydrochloric acid solution, 25 ° C, 12 hours immersion

Effect example 2

The corrosion resistance of the samples from Example 3 was tested. The results are in 11 (Table 5) shown. A solution or reagents such as 20% nitric acid, 50% hydrofluoric acid, 20% sulfuric acid, 20% phosphoric acid, 28% ammonia water, 28% caustic soda, 50% formic acid, 20% - Acetic acid, oxalic acid, organic solvent (acetone), ethanol, EDTA, tetramine and hydroxylamine hydrochloric acid were prepared. Various materials were immersed in the solutions or reagents for 24 hours at room temperature (30 ° C). The evaluation of the corrosion resistance was expressed by the weight loss during the immersion. In each test liquid, the samples of Example 3 had improved corrosion resistance from the point of view of weight loss and the observed appearance compared to the autocatalytically nickel-coated and non-fluorinated samples of Example 3.

Table 5 Results of corrosion resistance

Test conditions: various reagents at 25 ° C. Weight loss was calculated after 24 hours of immersion.
Notes * 1 - 100 hour immersion
Notes * 2 - 300 hour immersion

The wear resistance of the samples of the Production example 2 and examples 3 and 4 were carried out with a Scratch tester tested. The results are shown in Table 6. Although not a big difference in the static coefficient of friction between the manufacturing example 2 and each of Examples 3 and 4 was dynamic Friction coefficient of the fluorinated examples 3 and 4 about half that of the Preparation Example 2. Fluorinated Examples 3 and 4 show therefore improved sliding performance.

Table 6 Measurement result of the scratch wear resistance test

(Remarks) wear resistance. You were left Pen continuously using a constant load (300 g) a scratch tester over a Slide the sample until the layer is broken. The time to break indicated.

The wear resistance test was under a constant load. As a result of the test is the sliding friction performance and the layer durability as flextime until the wear and tear Layer expressed a unit of time in Manufacturing Example 2, while in Example 3 30 Times as much and in example 4 is 208 times as much. In particular there in example 4, in which the fluoride layer is located on the order of μm is better wear resistance and endurance than autocatalytic Nickel plating, it was clarified that the durability of Example 4 of one for the practical use is satisfactory level.

Reference example 1

Differences between the natural oxide layer and the gas phase oxide layer, which are caused by the forced oxidation on the aluminum alloy, were investigated by AES. The test results are in 12 shown. The thickness of the natural oxide layer formed on the samples of Production Example 4 was rated at slightly more than about 550 angstroms. This classification was based on a little more than approx. 5 minutes of the half-time, in which the O detection intensity fell to half, and also on the basis of 115 angstroms of the etching rate (SiO ₂ correction). In contrast, it is clear that the oxidation layer of the samples, which were forcibly oxidized in the gas phase in Example 7, is up to 2500 angstroms from the same classification.

Comparative Example 2

Differences between the natural oxide layer and the gas phase oxide layer, which are caused by the forced oxidation on the copper alloy, were investigated by AES. The test results are in 13 shown. The thickness of the natural oxide layer formed on the samples of Production Example 5 was rated at about 40 angstroms. This classification was based on approximately 20 seconds at half-time, in which the O detection intensity fell to half, and also on the basis of 115 angstroms of the etching rate (SiO ₂ correction). In contrast, it is clear that the oxidation layer of the samples, which were forcibly oxidized in the gas phase in Example 8, is up to 1 μm and more, since the oxide layer was not removed by argon ion sputtering for 80 minutes.

Comparative Example 3

Differences between the liquid phase oxidation layer and the gas phase oxidation layer were investigated by AES. The test results are in 14 shown. The thickness of the liquid phase oxidation layer formed on the samples of Example 9 was rated at 200 angstroms. This classification took place after about 100 seconds of the half-time, in which the O detection intensity fell to half, and also from 115 angstroms of the etching rate (SiO ₂ correction).

In the meantime, the samples of Example 3 forcibly oxidized by the oxygen gas. In this At this stage, the samples were removed from the reaction furnace. It's clear, that the oxidation layer of such samples unlike example 9 to approximately 0.6 µm, since the oxide layer is removed by argon ion sputtering for approx. 55 minutes becomes.

The thick fluorinated layer that achieved by the present invention has an improved resistance against acid and lye, and is therefore extremely useful, among other things, for the plant components of machines and devices related to semiconductors. The metal material or the metal layer on which the fluorinated surface layer is located is therefore extremely useful for manufacturing plants of semiconductor devices and plant parts of machines and devices, who work with vacuum.

Claims (6)

Fluorinated metal with a fluorinated layer, in which at least one metal is selected from the group consisting of aluminum, nickel, copper and silver, characterized in that it is formed in that either a surface of a monolithic metal or a surface of one a thin metal layer formed from a monolithic material is forcibly oxidized; and then fluorinating the positively oxidized surface to obtain 1 μm or more fluorinated layer thickness; in which the fluorinated layer consists of a first layer consisting essentially of a fluoride of the metal and a second layer of the metal which lies below the first layer and into which fluorine has diffused. The fluorinated metal of claim 1, wherein the metal Is aluminum and in which the fluorinated layer consists of a first Layer exists in which the oxygen of the positively oxidized layer is replaced by fluorine to a degree lower than that Degree of detection of oxygen, and from a second layer, the is under the first layer and made of monolithic aluminum or the thin one Aluminum layer exists, and in the fluorine has diffused. The fluorinated metal of claims 1 and 2, wherein a fluorination time is approximately 12 to 24 hours. Metal fluorination process, the following steps includes: Forced oxidizing either a surface of one monolithic metal or a surface of a thin metal layer on one monololithic material by an oxidation material in which at least one metal is selected from the group consisting of aluminum, There is nickel, copper and silver; and the resulting positively oxidized Layer in contact with a fluorination gas to make a fluorinated one Form layer having a thickness of 1 micron or more; at where the metal is aluminum, and where the fluorinated layer consists of a first layer, which essentially consists of a Aluminum fluoride, and a second layer from the monolithic aluminum, which lies under the first layer, and into which fluorine has diffused. A fluorination process according to claim 4, wherein the The step of forcibly oxidizing a surface comprises previously a thin aluminum layer on a monolithic material. Fluorination method according to claim 4 and 5, which has a fluorination time of about 12 to 24 hours.