JPH05214526A - Ceramic rotational cathode target and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a ceramic rotational cathode target by forming a ceramic layer and an undercoat layer on a cylindrical target holder and thereafter thermally spraying ceramic powder having a specified metallic compsn. thereon. CONSTITUTION:A ceramic layer and an undercoat layer increasing the adhesive strength to the ceramic layer are formed on the outer surface of a cylindrical target holder, and after that, ceramic powder essentially consisting of Zr, Ti, Ta, Hf, Mo, W, Nb, Sn, La, In, Cr or the like (hereinafter referred to as metal M) are Si and contg. the total of the metal M and Si in the atomic ratio of 4:96 to 35:65 thereon to form a ceramic layer as a target. In this way, a transparent thin oxide film having high durability can be formed on a substrate of large area at a low temp. at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic rotating cathode target for use in forming a ceramic film, particularly an oxide transparent thin film having a low refractive index by sputtering, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a thin film is formed on a transparent substrate such as glass or plastic to add an optical function to a mirror, a heat ray reflecting glass, a low radiation glass, an interference filter, an antireflection coat for a camera lens or a spectacle lens. Etc. In a normal mirror, Ag is formed by an electroless plating method, or Al, Cr, or the like is formed by a vacuum deposition method, a sputtering method, or the like. Of these, the Cr film is relatively strong and is therefore used in part as a surface mirror with an exposed coated surface.

Titanium oxide, tin oxide and the like have been used as the heat ray reflective glass by spraying, CVD or dipping. Recently, a metal film, a nitride film, tin-doped indium oxide (ITO) or the like formed on the glass surface by a sputtering method has been used as a heat ray reflective glass. In the sputtering method, the film thickness can be easily controlled, a plurality of films can be continuously formed, and the transmittance, the reflectance, the color tone and the like can be designed in combination with the transparent oxide film. For this reason, demand is increasing for buildings that emphasize design.

Low-emissivity glass that reflects radiant heat from an indoor heater or wall to the indoor side is a ZnO / Ag / ZnO three-layer system in which silver is sandwiched by zinc oxide or ZnO / Ag / ZnO / A
It has a structure such as a 5-layer system of g / ZnO (see Japanese Patent Laid-Open No. 63-239043) and is used in the form of double-layer glass or laminated glass. In recent years, it has been remarkably popularized in cold regions of Europe. For the antireflection coating of a lens or the like, a high refractive index film such as titanium oxide or zirconium oxide and a low refractive index film such as silicon oxide or magnesium fluoride are alternately laminated. Usually, a vacuum vapor deposition method is used, and the substrate is heated during film formation to improve scratch resistance.

A surface mirror, a single-plate heat ray-reflecting glass, and an antireflection coat such as a lens are used in a state where the coated film is exposed to the air. Therefore, it must have excellent chemical stability and abrasion resistance. On the other hand, even low-reflection glass causes defective products due to scratches during transportation or handling before it becomes a double-glazing or laminated glass. Therefore, a protective film that is stable and has excellent abrasion resistance or an optical thin film that also serves as a protective film is desired.

To improve durability, a chemically stable and transparent oxide film is usually provided on the air side. Titanium oxide, tin oxide, tantalum oxide, zirconium oxide, silicon oxide and the like are used as these oxide films, and magnesium fluoride and the like are used as typical films having a low refractive index. Has been used. Titanium oxide, tin oxide, tantalum oxide, and zirconium oxide have a high refractive index, while silicon oxide and magnesium fluoride have a low refractive index.

However, it is difficult to form these films on a substrate having a large area, and it has not been possible to deal with a place where a large area is required to be formed, such as glass for buildings and glass for automobiles. The direct current sputtering method is most suitable for large area film formation, but there is no suitable target material that provides a transparent thin film having a low refractive index, and it is desirable to use the direct current sputtering method capable of large area film formation. Could not be obtained.

For example, in order to form a silicon oxide thin film by DC sputtering, a method of forming a silicon dioxide thin film by reactive sputtering of a conductive Si target in an atmosphere containing oxygen can be considered. As a result, the surface was oxidized and the conductivity was lowered, so that the sputtering could not be sustained stably. Further, the formed silicon dioxide thin film is weak against alkalinity and cannot endure long-term immersion. Therefore, the applicant of the present invention has proposed, in Japanese Patent Application No. 2-201149, an amorphous oxide thin film and a target having a high durability, a low refractive index, and a wide degree of freedom in optical design.

[0009]

On the other hand, a planar target for sputtering is formed by mixing raw materials of an inorganic compound,
It is created through processing and bonding and a long process to obtain a shape suitable for the firing and sputtering device. Of these, steps such as molding, firing, processing, and bonding do not require a large-scale jig device when the target is small, but the above-mentioned jig device is large in the case of a large target for a production machine, and ceramics are also used for bonding. When the target is bonded to the target holder metal plate, it is manufactured by dividing and processing and joining, but it requires labor and cost such as using a large-scale device and a large amount of expensive In solder.

Further, in the case of sputtering large-area glass for construction, a high sputtering power is applied to increase the film forming speed in order to improve productivity, but in this case, the cooling of the target limits the film forming speed. There are problems such as cracking and peeling.

A new type of magnetron type rotating cathode target, which is improved in these points, is known (see Japanese Patent Publication No. 58-500174). This is because the magnetic field generating means is installed inside the cylindrical target, and the sputtering is performed while rotating the target while cooling from the inside of the target, so that a larger power can be input per unit area than the planar target. Therefore, high-speed film formation is possible. Such a target is a cylindrical rotating cathode that is mostly made of a metal or alloy to be sputtered, and is manufactured on a cylindrical target holder when the material to be sputtered is a soft or brittle metal or alloy.

However, in the case of a metal target, it is possible to coat a multilayer film of oxides, nitrides, carbides, etc. in various sputtering atmospheres, but the coating film is damaged by a different atmosphere and the desired composition cannot be obtained. Further, a low-melting-point metal target has a drawback that it melts when too much power is applied, and a ceramic target is desired.

Japanese Patent Laid-Open No. 60-181270 proposes a method for producing a sputter target by thermal spraying, but the thermal spray film cannot be made thick due to the large difference in thermal expansion between ceramics and metal, and the thermal shock during use causes a close contact. There is a problem that the property is deteriorated and peeling occurs. There is also a method of manufacturing a ceramics sintered body into a cylindrical shape and joining it to a target holder metal with In metal, but it is difficult to manufacture and costly.

[0014]

The present invention has been made to solve the above-mentioned problems, and the outer surface of a cylindrical target holder is roughened, and a ceramic layer to be formed later and the target holder are formed on the outer surface of the cylindrical target holder. At least one layer of a layer made of a metal or an alloy having a coefficient of thermal expansion intermediate between that and a layer made of a metal or an alloy having a coefficient of thermal expansion similar to that of the ceramic layer is formed as an undercoat, and then a ceramic powder Is a semi-molten state in a high-temperature gas while being transported and attached onto the undercoat by this gas to form a ceramic layer serving as a target to be sputtered, a method of manufacturing a ceramic rotating cathode target, wherein the ceramic powder is , Zr, T
At least one of i, Ta, Hf, Mo, W, Nb, Sn, La, In, Cr (hereinafter referred to as metal M) and Si are main components, and the total amount of metal M and Si are atomic ratios. Provided is a method for producing a ceramic rotating cathode target, which is a powder having a ratio of 4:96 to 35:65.

Further, according to the present invention, a ceramic layer serving as a target to be sputtered is formed on the outer surface of a cylindrical target holder, and a metal or an alloy having a thermal expansion coefficient intermediate between those of the ceramic layer and the target holder. And at least one layer of a metal or an alloy having a thermal expansion coefficient similar to that of the ceramics layer is formed as an undercoat between the ceramics layer and the target holder. As the target, the ceramic layer contains at least one of Zr, Ti, Ta, Hf, Mo, W, Nb, Sn, La, In and Cr (hereinafter referred to as metal M) and Si as main components. Also provided is a ceramic rotating cathode target characterized by having the total amount of metal M and Si in an atomic ratio of 4:96 to 35:65.

According to the method of the present invention, basically, a ceramic powder is made into a semi-molten state by using, for example, a plasma spraying apparatus, and is sprayed and adhered to a target holder to directly form a ceramic layer as a target. By this process, the powder is packed in a mold and press-molded, the process of sintering it in an electric furnace, the process of sintering it by hot pressing, the process of modifying it into an appropriate shape, the process of joining ceramics and a holder. Don't need However, in the process of obtaining a thermal spraying powder, particularly in the case of a complex compound that is not easily available, it is prepared by utilizing chemical synthesis or solid phase reaction. This powder can be used by pulverizing and classifying it to a particle size that is suitable for thermal spraying and is easy to flow.

In the present invention, the ceramic layer is Zr, T
At least one of i, Ta, Hf, Mo, W, Nb, Sn, La, In, Cr (hereinafter referred to as metal M) and Si are main components, and the total amount of metal M and Si are atomic ratios. It has a ratio of 4:96 to 35:65. In particular, it is preferable to set the ratio to 4:96 to 15:85 because the thin film formed has a very low refractive index of 1.6 or less. Zr
When the content of the metal M such as Al is less than 4 atomic% in the total amount with Si, it is difficult to stably sputter due to surface oxidation of the target in an oxidizing atmosphere.
The formed thin film (eg, Zr and Si oxide film) has poor alkali resistance. If the content of the metal M such as Zr is more than 35 atom% in the total amount with Si, the refractive index of the formed thin film becomes high, which is not preferable.

The ceramic powder used in the present invention can be produced, for example, by the following method. For example, metal such as Zr M, Si, ZrSi ₂ , ZrO ₂ (including stabilized or partially stabilized ZrO ₂ containing ₃ to 8 mol% of Y ₂ O ₃ , CaO, MgO, etc.), powder of SiO ₂ or When forming a mixed powder and a non-oxide target, if necessary, a mixture of carbon powder for reducing the oxide in a high-temperature atmosphere furnace using chemical synthesis or solid-state reaction By firing, a lumpy single-type or complex-type powder is obtained.

It is preferable to grind this powder and classify it to a particle size of about 75 to 10 μm to obtain a ceramic powder for thermal spraying. If it is larger than 75 μm, it will be difficult to bring it into a semi-molten state in a high temperature gas, and if it is smaller than 10 μm, it will be dispersed in the gas at the time of thermal spraying and it will be difficult to adhere to the target holder.

It should be noted that Fe, Al, M is added to the above-mentioned ceramic powder.
The total amount of g, Y, Mn, and H may be 3 wt% or less, and C may be 20 wt% or less because it disappears as CO ₂ during film formation. Further, it may contain Cu, V, Co, Rh, Ir and the like in the amount of impurities.

As the cylindrical target holder, stainless steel, copper, Ti, Mo, or the like having a thermal expansion coefficient similar to that of a ceramic layer can be used, and the outer surface of the ceramic target layer is improved to improve adhesion before thermal spraying of the ceramic powder. by such sandblasting with abrasive grains as Al ₂ O ₃ or SiC, it is necessary to have roughened. Alternatively, prior to the thermal spraying of the ceramic powder, the outer surface of the ceramic powder is processed into a V-groove shape or a screw shape, and then sandblasted with Al ₂ O ₃ or SiC abrasive grains to roughen it so that the adhesion is improved. Is also preferable.

The cylindrical target holder having a roughened outer surface has an undercoat in order to reduce the difference in thermal expansion between the ceramic layer and the target holder and to increase the adhesion to withstand peeling due to heat shock during sputtering. Is preferably formed. As such an undercoat, a layer made of a metal or an alloy having a thermal expansion coefficient intermediate between the target holder and the target material (hereinafter,
It is preferable that at least one layer out of a layer (hereinafter referred to as layer A) and a layer made of a metal or an alloy having a thermal expansion coefficient close to that of the target material (hereinafter referred to as layer B), and its powder are plasma-sprayed. In particular, it is optimal to form both layers and to have a structure of target holder / A layer / B layer / target material.

Even if the undercoat is only the B layer, since the metal and the alloy have high elasticity and small brittleness, the adhesion of the target material to the target holder can be enhanced. The thermal expansion coefficient of the B layer is preferably within the range of ± 2 × 10 ⁻⁶ / ° C. of the thermal expansion coefficient of the ceramic layer.

The material of the undercoat is Mo, Ti, N
i, Nb, Ta, W, Ni-Al, Ni-Cr, Ni-Cr-Al, Ni-Cr-Al-Y, Ni-
A conductive powder such as Co-Cr-Al-Y can be used.
The thickness of each undercoat is preferably about 30 to 100 μm.

Specifically, the material of the undercoat changes depending on the coefficient of thermal expansion of the ceramic layer. (Cu or SUS304 that can be used for the target holder
And the like have a coefficient of thermal expansion of 17 to 18 × 10 ⁻⁶ / ° C. )

For example, the ceramic layer is Hf-Si.
System, Cr-Si system, Sn-Si system, Zr-Si system (Z
When Zr is smaller than r: Si (atomic ratio) = 33: 67) (coefficient of thermal expansion 5 to 6 × 10 ⁻⁶ / ° C.), the preferable thermal expansion coefficient of the undercoat A layer is 12 to 15 ×.
10 ⁻⁶ / ° C., and its material is Ni, Ni—A
1, Ni-Cr, Ni-Cr-Al, Ni-Cr-Al
-Y, Ni-Co-Cr-Al-Y, etc. are mentioned. The thermal expansion coefficient of the undercoat B layer is preferably 5-8.
× 10 ^-6 / ° C, and its material is Mo, W, T
a, Nb and the like.

The ceramic layer is made of Ta--Si,
Ti-Si system (when Ti is less than Ti: Si (atomic ratio) = 33:67), Zr-Si system (Zr: Si (atomic ratio) = 33:67 or when Zr is more than this, ZrS
(including i ₂ ), etc. (coefficient of thermal expansion 8 to 9 × 10 ⁻⁶ / ° C.), the preferable thermal expansion coefficient of the undercoat A layer is 12
˜15 × 10 ⁻⁶ / ° C., and its material is Ni,
Ni-Al, Ni-Cr, Ni-Cr-Al, Ni-C
Examples thereof include r-Al-Y and Ni-Co-Cr-Al-Y. The thermal expansion coefficient of the undercoat B layer is preferably 8 to 10 × 10 ⁻⁶ / ° C., and the material thereof is T
i, Nb and the like.

Further, the ceramic layer is made of a Ti--Si system (Ti: Si (atomic ratio) = 33: 67 or T
When i is large, TiSi ₂ is included), etc. (coefficient of thermal expansion is 10)
˜13 × 10 ⁻⁶ / ° C.), the preferable thermal expansion coefficient of the undercoat is 10 to 13 × 10 ⁻⁶ / ° C., and its material is Ni, Ni—Al, Ni—Cr, Ni—
Cr-Al, Ni-Cr-Al-Y, Ni-Co-Cr
-Al-Y etc. are mentioned. When the difference in the coefficient of thermal expansion between the ceramic layer and the target holder is small as described above, the undercoat may be a single layer. Further, among such undercoat materials, the composition ratio may be changed to provide two layers, a layer having a thermal expansion coefficient close to that of the target holder and a layer having a thermal expansion coefficient close to that of the ceramics layer.

In addition, the above-mentioned ceramic powder is placed in a high temperature gas, preferably in a high temperature gas under a non-oxidizing atmosphere such as Ar, N ₂ or He (“in a high temperature gas under a non-oxidizing atmosphere” means a non- In a high-temperature gas shielded by an oxidizing atmosphere, the same shall apply hereinafter), and while being in a semi-molten state, this gas is transported and deposited on the undercoat to form a ceramic layer as a target to be sputtered. In particular, it is preferably formed by plasma spraying in hot gas plasma, preferably hot plasma in a non-oxidizing atmosphere. By inserting the undercoat, a stable ceramic layer having a film thickness of 2 to 5 mm or more can be formed.

Also when forming the above-mentioned undercoat, it is preferable to form it by a plasma spraying method performed in high temperature plasma, preferably in high temperature plasma in a non-oxidizing atmosphere.

When the ceramic powder is formed in a semi-molten state in a high-temperature gas in a non-oxidizing atmosphere and adhered onto the undercoat to form the ceramic layer, the ceramic powder is less oxidized during the formation of the ceramic layer. A uniform ceramic layer can be formed without any change in the chemical composition.

The rotary cathode target manufactured in this manner has good heat conduction from the target material to the target holder and further to the cathode electrode, and since it firmly adheres to the target holder, high sputtering for increasing the film formation rate is achieved. Even when power is applied, sufficient cooling is performed, and a large amount of power can be applied per unit area without peeling or cracking of the target due to a sudden heat shock.

Further, in the manufacturing method of the present invention, when the ceramic layer is formed in a non-oxidizing atmosphere, a uniform target can be formed with little oxidation at the time of forming the ceramic layer and no change in chemical composition.

Further, since the erosion zone of the target is the entire surface, there is an advantage that the utilization efficiency of the target is higher than that of the planar type. Further, even if the eroded portion of the target is thinned, the original state can be restored by spraying the sprayed powder of the same material on the portion where the target material is reduced. Further, it is possible to easily give the distribution of the thickness of the target depending on the location, and thereby it is possible to control the strength distribution of the magnetic field and the distribution of the temperature on the target surface to control the thickness distribution of the thin film formed.

If the manufacturing method of the present invention is applied to a conventional planar type target, it is possible to easily manufacture a target which is homogeneous and has high adhesion without the need for bonding the target and the target holder, and it is also possible to regenerate the eroded portion. .. Further, the ceramic rotating cathode target of the present invention can be used in both DC and RF sputtering devices by magnetron sputtering, high-speed film formation, high target use efficiency, and stable film formation.

Using the ceramic rotating cathode target of the present invention, in a mixed atmosphere of Ar and O ₂ , a usual 1 × 10 ⁻³ to
When sputtered in a vacuum of about 1 × 10 ^-2 Torr, Zr, Ti, T
A low-refractive index film made of an oxide containing at least one of a, Hf, Mo, W, Nb, Sn, La, In, and Cr (hereinafter referred to as metal M) and Si is uniformly and rapidly formed. can do.

Since the target of the present invention is electrically conductive and has little surface oxidation of the target during sputtering, direct current (DC) sputtering can be used for film formation, and a uniform film over a large area can be formed at high speed. .. This is because Zr, Ti, Ta, Hf, Mo, W, Nb, La, In, Cr, etc. in the target exist mostly as silicon compounds, and Sn exists as a Si-Sn alloy. It is considered that this is because the activity is low and thus it is difficult to be oxidized, and acts to suppress the decrease in conductivity due to the surface oxidation of the target.

The ceramic rotating cathode target of the present invention can be used in both DC and RF sputtering devices by magnetron sputtering, high-speed film formation and high target use efficiency, and stable film formation is possible. ..

[0039]

【Example】

[Example 1] In this example, a method for producing a Si-Zr ceramic rotating cathode target capable of stably forming an oxide film having a low refractive index and excellent durability at a high speed will be described. First, a mixture of ZrO ₂ , SiO ₂ , and carbon as a ceramic powder material for thermal spraying was reacted at a high temperature in a non-oxidizing atmosphere to obtain a lump-shaped sintered product. Crush and classify this lump powder
Si-Zr (Si: Zr = 9: 1 (atomic ratio)) powder having a particle size of 75 to 20 μm and a purity of 99.5% was obtained.

[0040] Inner Diameter 50.5mmφ x Outer Diameter 67.5mmφ x Length 406mm
The copper cylindrical target holder of was attached to a lathe, and the outer surface side was roughened by sandblasting using Al ₂ O ₃ abrasive grains. Next, as an undercoat, Ni-Al (9: 1) alloy powder was plasma sprayed (using a Metco sprayer) to give a coating with a film thickness of 50 μm. This plasma spraying was performed by using Ar gas as the plasma gas and applying a power of 700 A · 35 KV at a flow rate of 42.5 liters per minute.
Ni-Al (9: 1) by Ar gas plasma at 0000 ~ 20000 ℃
The alloy powder of No. 1 was instantaneously heated, transported together with the gas to the target holder, and agglomerated therein. The undercoat was formed by repeating the operation of moving the plasma spray gun left and right while rotating the target holder on the lathe.

Next, using the above-mentioned Si-Zr powder, a Si-Zr (Si: Zr = Si: Zr =
A rotating cathode target coated with 9: 1 (atomic ratio) was obtained. The Si-Zr rotating cathode target thus obtained was loaded into a magnetron sputtering apparatus to form a SiZr _x O _y film (Si: Zr: O = 9: 1: 20 (atomic ratio)) on a glass substrate. .. The formation conditions are 1 × 10 ^-3 to 1 in a mixed atmosphere of Ar + O _2.
Sputtering was performed in a vacuum of about 10 ⁻² Torr to obtain a transparent oxide film with a low refractive index of 1000 Å.

The above target was more resistant to damage due to heat shock than a planar type target in which ceramics were made by a conventional ceramic method and attached to a target holder. In the above conventional method, cracks occur at a sputtering power of about 1.2 KW and partial peeling occurs, but with the rotating cathode of the present invention, no cracks are observed even at 4 KW, and arcing does not occur and stable film formation is possible. With the method described above, a high film forming rate of 100 Å / sec, which is about 4 times the film forming rate of 25 Å / sec, was obtained. The obtained oxide film had a low refractive index of 1.49 and had excellent alkali resistance.

Comparative Example 1 In the same manner as in Example 1, a rotating cathode in which Si powder was plasma sprayed was prepared. The film was formed under the same sputtering conditions, but arcing was severe,
The film could not be stably formed.

Comparative Example 2 Si-Zr (Si: Z
A conventional planar target was prepared with a composition of r = 9: 1 (atomic ratio). When sputtering was performed using this, the target was cracked or partly peeled off, and a stable film could not be formed.

Table 1 shows a comparison between Example 1 and Comparative Examples 1 and 2. The alkali resistance of the films shown in Table 1 is that when the film was immersed in 0.1N NaOH for 240 hours at room temperature, the rate of change in film thickness was 10% or less before immersion, and the film was dissolved. It was set to x.

[0046]

[Table 1]

[Example 2] (Two layers of undercoat, Ar
Example of gas shield atmosphere) A mixture of ZrO ₂ , SiO ₂ and carbon as a ceramic powder material for thermal spraying was reacted at a high temperature in a non-oxidizing atmosphere to obtain a lump-shaped sintered product. This lump powder is crushed and classified to 99.5
% Si-Zr (Si: Zr = 9: 1 (atomic ratio)) powder having a particle size of 75 to 20 μm was obtained.

Inner Diameter 50.5 mmφ x Outer Diameter 67.5 mmφ x Length 406 mm
The copper cylindrical target holder of was attached to a lathe, the outer surface side was processed into a screw shape, and the surface was roughened by sandblasting using Al ₂ O ₃ abrasive grains. Next, as an undercoat, a Ni-Al (compounding weight ratio 8: 2) alloy powder was plasma sprayed (using a Metco sprayer) in an argon gas shield atmosphere to form a coating having a film thickness of 50 μm.

Furthermore, a Mo metal powder having a thermal expansion coefficient similar to that of a Si-Zr (Si: Zr = 9: 1 (atomic ratio)) ceramic layer was plasma-sprayed in an Ar gas shield atmosphere on this, and a film thickness was obtained.
A coating of 50 μm was obtained.

The plasma spraying in the Ar gas shield atmosphere is carried out in an atmosphere in which the spray gun and the cylindrical target holder are surrounded by a metal shield box and Ar gas is spirally flown in the shield box. Gas is used as plasma gas, and the flow rate of 42.5 liters per minute is 700A
Performed by applying a power of 35KV, Ni-Al (compounding weight ratio 8: 2) alloy powder and Mo metal powder were instantaneously heated by Ar gas plasma at 10000 to 20000 ° C and transported to the target holder together with the gas. Then, it was made to aggregate there. The undercoat was formed by repeating the operation of moving the plasma spray gun left and right while rotating the target holder on the lathe.

Next, using the above-mentioned Si-Zr powder, a Si-Zr (Si: Zr
= 9: 1 (atomic ratio)) coated rotating cathode target was obtained. The relative density of this ceramic target layer is 91%
The O ₂ content was 1.0 wt%. The Si-Zr rotary castor target obtained in this way was loaded into a magnetron sputtering system, and a SiZr _x O _y film (Si: Zr: O =
9: 1: 20 (atomic ratio)) was formed. The formation conditions were sputtering in a mixed atmosphere of Ar + O ₂ in a vacuum of about 1 × 10 ⁻³ to 1 × 10 ⁻² Torr to obtain a transparent oxide film with a low refractive index of 1000 Å. The chemical composition Si / Zr atomic ratio of this low refractive index transparent oxide film was the same as that of the target.

The above target was more resistant to damage due to heat shock than a planar type target in which ceramics were made by a conventional ceramic method and attached to a target holder. In the above conventional method, cracks occur at a sputtering power of about 1.2 KW and partial peeling occurs, but with the rotating cathode of the present invention, no cracks are observed even at 4 KW, and arcing does not occur and stable film formation is possible. With the method described above, a high film forming rate of 100 Å / sec, which is about 4 times the film forming rate of 25 Å / sec, was obtained. The obtained oxide film had a low refractive index of 1.49 and had excellent alkali resistance.

[Examples 3 to 9] In the same manner as in Example 2,
Various targets were prepared by changing the constituent materials of the target and the ratio thereof, and using the same, film formation was performed by sputtering in the same manner as in Example 2. However, in Examples 3 and 7, Ti metal powder was used instead of Mo metal powder, and Ni—Al (50 μm) / Ti (50 μm) was used.
Was used as a two-layer undercoat. In addition, in Example 6, a single layer of Ni—Al (100 μm) was used as the undercoat. In Examples 4, 5, 8 and 9, the same undercoat as in Example 2 was used. As described above, the method of forming the undercoat is the same as that of the second embodiment.

[Comparative Example 3] A rotating cathode was prepared in the same manner as in Example 2 except that the ceramic layer serving as the target was formed using Si powder. The film was formed under the same sputtering conditions, but arcing was severely generated, and the film could not be stably formed.

Table 2 shows a comparison between Examples 2 to 9 and Comparative Example 3. The alkali resistance of the films shown in Table 1 is that when the film was immersed in 0.1N NaOH for 240 hours at room temperature, the rate of change in film thickness was 10% or less before immersion, and the film was dissolved. It was set to x.

[0056]

[Table 2]

[0057]

According to the method of the present invention, since the target is formed by using the thermal spraying method, the conventional ceramics manufacturing equipment is not required, and the target can be easily formed at a low cost and in a short time without the work joining step. It can be applied to many inorganic materials. In particular, powders of refractory substances and refractory metals which are difficult to be made into ceramics are cheaper, and it is particularly effective when such substances are targeted.

Further, in the production method of the present invention, when the ceramic layer is formed in a non-oxidizing atmosphere, when a metal that is easily oxidized or a compound of a binary system or more is targeted, the chemical composition does not change and is uniform. Can form a target.

When the present invention is applied to the conventional planar type target, the bonding between the target and the target holder is unnecessary, the target can be easily manufactured, and the eroded portion can be regenerated.

When the rotating cathode target of the present invention is used, the cooling efficiency during sputtering is also high, and even if the sputtering power is increased, there is no cracking or damage to the target, and stable high-speed film formation is possible at low temperatures. The industrial value is enormous because the productivity of large-area glass for automobiles and automobiles is remarkably improved and the target use efficiency is increased.

By using the rotating cathode of the present invention, a transparent thin film having a low refractive index and excellent alkali resistance can be stably provided at a high speed over a large area. Further, the optical design of the thin film can be facilitated by combining with the transparent oxide thin film having a high refractive index. Further, since the low refractive index film obtained by the present invention has chemical stability, it can be used as an overcoat for various articles. For example, it is most suitable for the outermost layer of heat-reflecting glass for buildings and automobiles, the protective plate of the reading part of bar code readers, antireflection film, spectacle lenses, etc. Also, it is widely used for mechanical elements and is a coating for sliding members It can also be used for timber.

Claims (8)

[Claims] 1. An outer surface of a cylindrical target holder is roughened, and a layer made of a metal or an alloy having a coefficient of thermal expansion intermediate between the ceramic layer to be formed later and the target holder, and the ceramic layer are formed on the outer surface. At least one layer of a metal or an alloy having an approximate coefficient of thermal expansion is formed as an undercoat, and then the ceramic powder is semi-molten in a high temperature gas while being transported onto the undercoat by the gas. A method of manufacturing a ceramic rotating cathode target, comprising forming a ceramic layer as a target to be deposited and sputtered, wherein the ceramic powder is Zr, Ti, Ta, Hf, Mo, W, Nb, S.
Powder containing at least one of n, La, In and Cr (hereinafter referred to as metal M) and Si as main components, and the total amount of metal M and Si in an atomic ratio of 4:96 to 35:65. And a method of manufacturing a ceramics rotating cathode target. 2. The method for producing a ceramic rotating cathode target according to claim 1, wherein the ceramic powder is adhered to a target holder by a plasma spraying method to form a ceramic layer. 3. The method for producing a ceramic rotating cathode target according to claim 1, wherein the undercoat is formed by a plasma spraying method. 4. A ceramic powder, which is in a semi-molten state in a high temperature gas under a non-oxidizing atmosphere, is transported and adhered onto the undercoat by the gas to form a ceramic layer as a target to be sputtered. The method for producing a ceramic rotating cathode target according to any one of claims 1 to 3, which is characterized in that. 5. The method for producing a ceramic rotating cathode target according to claim 1, wherein the ceramic powder is adhered to a target holder by plasma spraying in a non-oxidizing atmosphere to form a ceramic layer. 6. The method for producing a ceramic rotating cathode target according to claim 1, wherein the undercoat is formed by a plasma spraying method in a non-oxidizing atmosphere. 7. On the outer surface of the cylindrical target holder,
A layer made of a metal or alloy having a coefficient of thermal expansion intermediate between that of the ceramic layer and the target holder, and a metal or alloy having a coefficient of thermal expansion close to that of the ceramic layer, in which a ceramic layer serving as a target to be sputtered is formed. Is a ceramic rotating cathode target formed as an undercoat between the ceramic layer and the target holder, wherein the ceramic layer is Zr, T
At least one of i, Ta, Hf, Mo, W, Nb, Sn, La, In, Cr (hereinafter referred to as metal M) and Si are main components, and the total amount of metal M and Si are atomic ratios. A ceramic rotating cathode target characterized by having a ratio of 4:96 to 35:65. 8. A method for forming a film by sputtering, which comprises forming a low refractive index film by sputtering the ceramic rotating cathode target according to claim 7.