JP4993297B2 - SiO sintered vapor deposition material - Google Patents

Description

The present invention relates to SiO sintered deposition material used to form the deposited film of SiO (silicon monoxide).

  Packaging materials for foods and pharmaceuticals, and resin substrates for flat panel displays such as liquid crystals and organic ELs are required to have a high gas barrier property. From this point of view, a gas barrier film is known in which a metal such as aluminum or a metal oxide such as silicon oxide, aluminum oxide or magnesium oxide is deposited on a polymer film substrate. Attracts attention because it has both high transparency and high gas barrier properties.

As a vapor deposition material used for forming such a SiO vapor deposition film, SiO manufactured using a vacuum agglomeration method is usually used. The vacuum agglomeration method is a method for producing SiO by mixing and heating Si and SiO ₂ in a raw material chamber, and vapor-depositing SiO on the inner surface of a tubular agglomeration chamber connected to the raw material chamber. It is. The produced SiO is a dense precipitate, which may be cut into a predetermined tablet shape and used directly as a vapor deposition material. In other cases, the precipitate is once crushed into a powder and then sintered into a predetermined tablet shape. In some cases, it may be used. Since characteristic values such as bulk density can be controlled over a wide range, a sintered body is relatively often used as a vapor deposition material.

  By the way, splash is one of the phenomena which become a problem in the formation process of SiO vapor deposition film. This phenomenon is a fine jumping phenomenon of the melt from the vapor deposition material. When this occurs during film formation, defects such as pinholes are generated in the formed vapor deposition film, and the film quality is remarkably deteriorated. This splash phenomenon becomes more prominent as the film formation rate is increased, and it is a factor that hinders the film formation rate. For this reason, in the formation work of SiO vapor deposition film, suppression of the occurrence of splash has become an important technical problem, and approaches have been attempted from various directions to solve the problem. From the vapor deposition material side, attempts have been made to improve physical properties such as material density and brittleness.

  That is, regarding the physical properties of the vapor deposition material, it is considered that the more dense and hard the splash is, the less likely it is that splash occurs. In accordance with this idea, the weight reduction rate (Ratra value) in the Latra test is 1.0% or less. A certain vapor deposition type SiO vapor deposition material is proposed in US Pat.

Special Table 2003/025246

On the other hand, regarding the powder sintered type SiO vapor deposition material, Patent Document 2 describes the effectiveness of increasing the bulk density to 1.60 g / cm ³ or more by hot pressing at high temperature and high pressure. In the case of powder sintered SiO deposition material, the higher the sintering temperature in the sintering process, the higher the density, so the sintering temperature is set to a high temperature of 1200 ° C. or higher. The technology that suppresses splash by lowering the sintering temperature and suppressing the precipitation of Si is patented from the idea that SiO is thermally decomposed due to the high sintering temperature and Si is precipitated. Presented by reference 3.

Special table 2003/010112 JP 2006-348348 A

  Vapor deposition materials with improved physical properties (dense and hard materials) are less likely to break during use and have good usability. However, with respect to the suppression of splash, the expected effect has not been achieved.

  On the other hand, a measure for suppressing the Si precipitation due to the thermal decomposition of SiO by lowering the sintering temperature is effective in suppressing the splash. However, the mechanical strength of the vapor deposition material is reduced, which may cause damage during use. In order to avoid a decrease in mechanical strength when the sintering temperature is lowered, in the technology of Patent Document 3, SiO that is a raw material of powder sintering type vapor deposition material, that is, out of deposited SiO produced by vacuum agglomeration method Measures have been proposed to selectively use SiO deposited at a low temperature in the aggregation tube, but there is a problem that the raw material cost increases. Moreover, it is difficult to improve the mechanical strength as the sintering temperature increases.

  In addition to this, with the recent demand for higher quality of the deposited film, the quality requirements for the deposited material have become stricter year by year, and the suppression of the generation of finer particles than the splash has been strongly demanded. It was.

  That is, the splash is relatively large particles scattered from the vapor deposition material in the vapor deposition film forming process, and causes a pinhole in the vapor deposition film. The size is visible, and is typically about 0.1 mm. On the other hand, the particles are particles that are much smaller than the splash scattered from the vapor deposition material, and adhere to the vapor deposition film. The size is in the order of μm which is invisible or less.

  This particle has not been regarded as a problem in the past, but it has become a problem as the substrate structure of organic EL or the like is miniaturized, and the reduction of the problem has begun to be demanded. However, even with the splash countermeasure described in the cited document 3, it is difficult to reduce the particles.

An object of the present invention is to provide a high-strength and low-cost SiO sintered vapor deposition material that can remarkably suppress the generation of splash and particles.

It is considered that the cause of splash in the formation process of the SiO vapor deposition film is unreacted Si in the vapor deposition material. This is because the vapor pressure of Si is lower than that of SiO and even lower than SiO ₂ which is lower than that of SiO. For this reason, Si does not evaporate in the vapor deposition process, but remains on the surface of the vapor deposition material, causing splash and particles. From this viewpoint, the technique described in Patent Document 3 reduces the amount of Si in the vapor deposition material by a material manufacturing process (sintering process). However, as described above, there are secondary problems in this technology.

  The present inventor has continued the approach for suppressing the splash from various directions, and has found the following facts in the process.

  In order to suppress the occurrence of splash in the vapor deposition process, it is not always necessary to reduce the amount of Si in the vapor deposition material. Even if the amount of Si in the vapor deposition material is large, Si is a problem in the vapor deposition process (deposition film formation process). If this is not done, the occurrence of splash may be suppressed. That is, even if Si is present in the vapor deposition material, the problem of splash due to Si can be solved if the Si can be changed into a Si oxide having a low vapor pressure by the vapor deposition process. As a result of analyzing and examining experimental data from this point of view, it has been found effective to increase the amount of O in the vapor deposition material.

  The reason why O in the vapor deposition material is effective will be described in detail later. However, if excessive O is present in the vapor deposition material, Si in the vapor deposition material is oxidized in the vapor deposition process to form a Si oxide having a low vapor pressure. It is considered that the Si does not remain unreacted. In addition, as a method of increasing the amount of O in the vapor deposition material, in order to ensure strength in the manufacturing process, before performing main sintering at a temperature of 1000 ° C. or higher in an inert atmosphere furnace, in an oxygen-containing atmosphere such as the air It has been found that it is convenient and effective to insert a low-temperature sintering step of 900 ° C. or lower. If the presence of Si in the vapor deposition material is allowed in this way, high temperature sintering is possible in the vapor deposition material manufacturing process, and the vapor deposition material is densified.

  Increasing the sintering temperature in the production process of powder-sintered SiO vapor deposition material, and the densification of the vapor deposition material due to this, are still very effective in suppressing splash and ensuring mechanical strength, apart from the problem of Si precipitation. It can be a means. For this reason, the increase in the amount of O in the vapor deposition material, combined with the allowance of high-temperature sintering, effectively reduces the occurrence of splash in terms of reducing unreacted Si in the vapor deposition process and densifying the vapor deposition material. In addition, the generation of particles can be effectively suppressed.

The present invention has been developed on the basis of such knowledge, and is an SiO sintered vapor deposition material used for forming a SiO vapor deposition film, which is obtained by quantitative analysis of a standard sample made of SiO ₂ by EPMA. The ratio (a / a ₀ ) of the Si ratio a to the theoretical value a ₀ (≈1.14) is set as a correction coefficient K, and the O / Si ratio measured value A by EPMA is corrected by the correction coefficient K. The oxygen quantitative analysis value O ₁ [= 100 / (1 + 1 / A ₁ )] obtained from the correction value A ₁ (= 1 / K · A) of the / Si ratio is 44 to 49 wt%, and the compression fracture strength is It is a SiO sintered vapor deposition material of 15 MPa or more.

The SiO sintered vapor deposition material of the present invention comprises a molding step of forming raw material powder made of SiO into a vapor deposition material shape, a weak oxidation step of low-temperature sintering of a molded body of SiO in an oxygen-containing atmosphere, and a low-temperature sintered body. and the sintering step of high temperature sintering in a non-oxidizing atmosphere is produced by including methods.

In the SiO sintered vapor deposition material of the present invention, with respect to the theoretical value a ₀ (≈1.14) of the O / Si ratio a when a standard sample made of SiO _{2 is} quantitatively analyzed by EPMA for evaluating the amount of oxygen in the material. Ratio (correction coefficient K = a / a ₀ ), O / Si ratio correction value A ₁ (= 1 / K · A) obtained by correcting the actual measurement value A of the O / Si ratio by EPMA with the correction coefficient K The oxygen quantitative analysis value O ₁ [= 100 / (1 + 1 / A ₁ )] obtained from the correction value A ₁ (= 1 / K · A) of the O / Si ratio is used. The reason will be described below.

  There is no method capable of directly and simply measuring the amount of O in a metal oxide such as SiO. For this reason, the composition of a metal oxide is generally expressed by a content ratio in terms of metal amount. Under such circumstances, EPMA can accurately measure the amount of O in the metal oxide with high reproducibility, although indirectly, from the element distribution state survey in the cross section of the metal oxide. However, the absolute value of the quantitative oxygen analysis value cannot be directly measured. For example, the amount of oxygen in SiO with a molar ratio of 1: 1 is about 36 wt% (Si atomic weight: 28.0855, O atomic weight: 15.99994), but the quantitative oxygen analysis value by EPMA is considerably smaller than this. .

For this reason, the present inventor also examined a method for accurately obtaining the amount of oxygen in SiO from quantitative analysis by EPMA. To that effect, rather than measuring only the O content in the SiO, to obtain the O / Si ratio by measuring both the O amount and the Si amount, the standard sample consisting of SiO _2, the theoretical value of quantitative analysis It was concluded that it was necessary to obtain the correction coefficient K in advance, and from these, an accurate quantitative analysis value of the amount of O in SiO was successfully obtained.

  EPMA is a wavelength dispersive electron beam macro analyzer (Electron Probe Micro Analyzer), and the measurement principle by this is as follows. When an accelerated electron beam is irradiated onto a material, characteristic X-rays, secondary electrons, Auger electrons, etc. jump out of the material. EPMA is a quantitative analysis device that focuses on these characteristic X-rays and detects and identifies constituent elements in the micro-region irradiated with the electron beam, and analyzes the concentration of each constituent element. An overall quantitative analysis can also be performed. However, since SiO, which is an object to be detected in the present invention, is a powder sintered body, the porous body has a rough surface, large irregular reflection, and large variations due to surface properties between samples, the amount of O is quantified with EPMA. Even if analyzed, the analytical value does not represent the exact amount of O in the sample.

  The O / Si ratio was introduced for the variation due to the surface property between samples, which is the first problem. If the O / Si ratio is determined by measuring the O amount and Si amount of the SiO sample, it is possible to eliminate the influence of the difference in reflectance due to the surface properties between the samples. When the reflectivity differs between samples, the quantitative analysis value of O and the quantitative analysis value of Si change in the same way. Therefore, the O / Si ratio obtained by EPMA is not uniform in the reflectance between samples. It is not affected.

The second problem is the difference between the quantitative analysis value and the actual value. EPMA conducts quantitative analysis of constituent elements focusing only on characteristic X-rays. For this reason, the measured value of the quantitative analysis does not match the actual element amount. To solve this problem, a correction coefficient K is obtained from the relationship between the analytical value obtained when the standard sample is quantitatively analyzed and the actual analytical value using a standard sample whose constituent element amount is known in advance. Here, although it is a standard sample, since a SiO sample is quantitatively analyzed, a standard sample of SiO should be used. However, SiO is easily oxidized and unstable in material, and the O / Si ratio is not always 1: 1. In contrast, since SiO ₂ has a very stable composition, SiO ₂ is used as a standard sample instead of SiO ₂ .

Since SiO ₂ is materially stable and used as quartz glass, it is dense and easy to mirror. Since both SiO and SiO ₂ are silicon oxides, the correction coefficient K obtained from the standard sample made of SiO ₂ can be used as the correction coefficient of the sample made of SiO ₂ . The SiO oxygen quantitative analysis value O ₁ thus obtained corresponds precisely to the actual oxygen amount of SiO. The validity of the oxygen quantitative analysis value O ₁ will be described below.

First step (calculation of correction coefficient K)
A standard sample made of SiO _{2 is} quantitatively analyzed by EPMA to determine the amount of O and the amount of Si. The ratio of the measured value of O amount to the measured value of Si amount is obtained. When the measured value of O amount is O ₀ (wt%) and the measured value of SiO is Si ₀ (wt%), the O / Si ratio a obtained from the measured value of the standard sample is O ₀ / Si ₀ . On the other hand, the actual O / Si ratio a (theoretical value) of the standard sample made of SiO ₂ is 53.26 / 46.74 (≈1.14). Therefore, the ratio (a / a ₀ ) to the theoretical value a ₀ (≈1.14) of the O / Si ratio a when a standard sample made of SiO _{2 is} quantitatively analyzed by EPMA is obtained. This ratio (a / a ₀ ) is a correction coefficient K for converting the measured value of O / Si into a real value. That is, a = K · a ₀ and K = a / a ₀ .

Second step (Measurement of oxygen quantitative analysis value O ₁ )
A sample of SiO is quantitatively analyzed by EPMA to determine the amount of O and the amount of Si. When the measured value of O amount is O ₁ (wt%) and the measured value of Si amount is Si ₁ (wt%), the O / Si ratio A obtained from the measured value of the SiO sample is determined by O ₁ / Si ₁ . . Since the corrected O / Si ratio A ₁ of the SiO sample is A = K · A ₁ , A ₁ = 1 / K · A. Here, O ₁ (wt%) + Si ₁ (wt%) = 100 (wt%), and O ₁ (wt%) = A ₁ · Si ₁ (wt%). When Si ₁ (wt%) is deleted from these equations, O ₁ (wt%) is obtained as 100 / (1 + 1 / A ₁ ). The oxygen quantitative analysis value O ₁ (wt%) [= 100 / (1 + 1 / A ₁ )] of the SiO sample thus obtained accurately reflects the actual oxygen amount.

In the SiO sintered vapor deposition material of the present invention, this oxygen quantitative analysis value O ₁ is 44 to 49 wt%, and the compression fracture strength is 15 MPa or more. O ₁ = 44 to 49 wt% generally corresponds to SiO x (1.3 to 1.4 ≦ x ≦ 1.6 to 1.7). Incidentally, the amount of O of the SiO sintered vapor deposition material manufactured by the method described in the cited document 3 is SiOx (x≈1) because the precipitation of Si due to thermal decomposition of SiO is suppressed by low-temperature sintering. The oxygen quantitative analysis value (wt%) is about 36%.

In the SiO sintered vapor deposition material of the present invention, the reason why the oxygen quantitative analysis value O ₁ is set to 44 to 49 wt% is that if it is less than 44 wt%, the amount of O in the material is insufficient, and excess Si in the material in the vapor deposition process. It remains unreacted and cannot sufficiently suppress the occurrence of splash and particles. On the other hand, if it exceeds 49 wt%, the characteristics approach that of SiO ₂ having a high vapor pressure, so that the film formation rate is significantly reduced in the vapor deposition process, which causes a problem in terms of productivity. A particularly preferable oxygen quantitative analysis value O ₁ is 44 to 47 wt%.

  In the SiO sintered vapor deposition material of the present invention, the compressive fracture strength is specified to be 15 MPa or more. This can be easily realized, for example, by increasing the sintering temperature in the material manufacturing process. When the compressive fracture strength is 15 MPa or more, the material is densified, and the occurrence of splash is suppressed from this point. Moreover, destruction during use is prevented, and usability is improved. This compressive fracture strength is preferably as high as possible from the viewpoints of splash prevention, usability, and the like. Specifically, it is preferably 30 MPa or more, but excessively high means an excessive increase in the sintering temperature, and is due to thermal decomposition of SiO. Since the precipitation amount of Si is excessively increased, there is a risk of causing problems in terms of splash and particle suppression. However, the present inventor has confirmed that there is no problem up to 51 MPa.

On the other hand, in the method for producing a SiO sintered vapor deposition material of the present invention, a weak oxidation step of sintering a molded body of SiO at a low temperature in an oxygen-containing atmosphere is particularly important. By passing through this process, SiO which comprises a molded object is a little oxidized in a low temperature sintering process, and the amount of O in a low temperature sintered body increases. Specifically, the amount of O in the low-temperature sintered body is 44 to 49 wt% in terms of the oxygen quantitative analysis value O1.

  The oxygen amount in the sintering atmosphere here is preferably 18 to 25 vol%, and there is no problem in the air. The sintering temperature is adjusted by the amount of oxygen in the sintering atmosphere, and is preferably 700 to 900 ° C. in the air. If the sintering temperature is too low, the amount of O in the low-temperature sintered body will not increase sufficiently. If it is too high, the amount of O increases too much. A particularly preferable sintering temperature when performing low-temperature sintering in the atmosphere is 700 to 800 ° C.

  In the main sintering process following the weak oxidation process, the low-temperature sintered body is sintered at a high temperature to increase the hardness and density. When the sintering temperature in this process is increased, SiO is thermally decomposed to produce Si, but O increased by low temperature sintering oxidizes this Si in the vapor deposition process to prevent the generation of surplus Si, and surplus Si Prevents the occurrence of splash and particles caused by Moreover, since the vapor deposition material is densified, the occurrence of splash and particles are also suppressed from this point.

The sintering temperature in the main sintering step is preferably 1000 to 1400 ° C. If this sintering temperature is too low, the denseness and hardness of the vapor deposition material will be insufficient, and there is a concern that the occurrence of splash and particles in the vapor deposition process will be problematic. There is also a concern that destruction may occur during the deposition. On the other hand, if it is too high, the reaction of 2SiO → Si + SiO ₂ tends to proceed. As a result, there is a concern that the amount of Si to be generated becomes excessive and the effect of suppression by weak oxidation is lost. A particularly preferable sintering temperature is 1200 to 1400 ° C.

The SiO sintered vapor deposition material of the present invention corrects the ratio (a / a ₀ ) to the theoretical value a ₀ (≈1.14) of the O / Si ratio a when a standard sample made of SiO ₂ is quantitatively analyzed by EPMA. The oxygen quantitative analysis value O obtained from the correction value A ₁ (= 1 / K · A) of the O / Si ratio obtained by correcting the actual measurement value A of the O / Si ratio by EPMA with the correction coefficient K. ₁ [= 100 / (1 + 1 / A ₁ )] is as high as 44 to 49%, so even if surplus Si is present in the material, this Si can be oxidized in the deposited film forming process. Since it can be changed to a Si oxide having a low vapor pressure, the occurrence of splash due to Si having a high vapor pressure can be prevented, and the generation of particles can also be effectively suppressed. Moreover, since the compressive fracture strength is as high as 15 MPa or more and the denseness is high, it can be expected to suppress splash and particles. Furthermore, destruction in the vapor deposition film forming process is prevented, and the usability is excellent.

  That is, in the past, high-temperature sintering for densification led to high Si, and when densification was ensured, generation of splash and particles due to Si could not be prevented. Then, the high O makes it possible to ensure the denseness and suppress the splash and particles caused by the high Si.

In the method for producing the SiO sintered vapor deposition material of the present invention, before the sintered body of SiO is sintered, fine oxidation by low-temperature sintering is performed in an oxygen-containing atmosphere to increase the amount of O. Even if the sintering temperature is increased and the denseness is increased, Si produced by the high-temperature sintering is oxidized by the vapor deposition process, so it is possible to effectively suppress the splash and particles caused by the excessive and excessive Si. High quality vapor deposition material that can be produced. In addition, since low-temperature sintering in an oxygen-containing atmosphere is low in cost, the high-quality material can be manufactured at low cost and excellent in economic efficiency.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a manufacturing process of a SiO sintered vapor deposition material of the present invention, FIG. 2 is a configuration diagram of a vacuum aggregating apparatus used for manufacturing a raw material (deposited SiO), and FIG. 3 is a splash generation in a vapor deposition film forming process. -It is an image figure which shows the principle of suppression.

In this embodiment, a vapor deposition material is manufactured through the following steps. The first step is the production of the raw material (deposited SiO). In this step, for example, a vacuum aggregating apparatus shown in FIG. 2 is used. The vacuum aggregating apparatus shown in FIG. 2 includes a raw material chamber 1 and a circular agglomerating chamber 2 connected thereon. In operation, the raw material chamber 1 is charged with a mixture of Si powder and SiO ₂ powder. The chamber is depressurized to a predetermined degree of vacuum, and the inside of the raw material chamber 1 is heated to a predetermined temperature (1200 to 1400 ° C.) with a heater disposed outside the raw material chamber 1. As a result, SiO vapor is generated in the raw material chamber 1 and introduced into the upper coagulation chamber 2.

  In the coagulation chamber 2, the coagulation tube temperature is controlled to several hundred degrees as the outer surface temperature. More specifically, the outer surface temperature of the aggregation tube decreases from the lower part to the upper part, and SiO is deposited in a region from about 800 ° C. to 200 ° C. Of the deposited SiO, SiO deposited in a high temperature region from 800 ° C. to around 400 ° C. is usually used as a deposition material. This is because the precipitates in the low temperature region are more fragile, and those precipitated in the high temperature region are excellent in denseness.

  When the deposited SiO is produced by the vacuum aggregating apparatus, it is pulverized to a predetermined particle size by a pulverizer. In the produced SiO powder, the particle size is important, and the particle size is preferably 5 to 50 μm, particularly preferably 10 to 30 μm, in terms of average particle size. This is because if the powder is too fine, the density of the compact does not increase and it becomes difficult to achieve high strength. On the other hand, in the case of coarse particles, moldability becomes difficult.

  When the SiO powder as a sintering raw material is manufactured, it is formed into a tablet shape for vapor deposition material (usually a cylindrical shape) using a predetermined binder, and is sintered at low temperature in the atmosphere. As described above, the sintering temperature is preferably 700 to 900 ° C, particularly preferably 700 to 800 ° C. By this low-temperature sintering in the atmosphere, SiO constituting the compact is slightly oxidized, and the amount of O is increased as compared with the case where the deposited SiO powder is directly subjected to high-temperature sintering.

  Sintering can be performed by hot pressing, but it is more economical to perform sintering using a binder for molding. As the binder, commercially available ones are not a problem, but those that can be removed at a low temperature of 500 ° C. or lower are particularly preferable. The addition amount of the binder is preferably 15 to 30% by weight. If the amount of the binder is too small, the moldability deteriorates. If the amount is too large, it becomes a slurry and the molding becomes difficult.

  When the low temperature sintering is completed, high temperature sintering is performed in a non-oxidizing atmosphere. As described above, the sintering temperature is preferably 1000 to 1400 ° C, particularly preferably 1200 to 1400 ° C. By this high-temperature sintering, the compact is densified to a high level and the mechanical strength is improved. On the other hand, SiO is thermally decomposed and Si is precipitated, and surplus Si is generated. However, this surplus Si is oxidized by the vapor deposition process due to O increased in the low temperature sintering process, and is changed to a Si oxide having a low vapor pressure, so that splash and particles are not generated.

Thus, the ratio (a / a ₀ ) to the theoretical value a ₀ (≈1.14) of the O / Si ratio a when a standard sample made of SiO _{2 is} quantitatively analyzed by EPMA is set as a correction coefficient K, and O / O by EPMA Quantitative oxygen analysis value O ₁ [= 100 / (1 + 1 //) obtained from correction value A ₁ (= 1 / K · A) of O / Si ratio obtained by correcting measured value A of Si ratio with correction coefficient K. A _1)] is at 44-49%, SiO sintered deposition material compression breaking strength of more than 15MPa is manufactured. Although such a SiO sintered vapor deposition material is high in strength, it can prevent the occurrence of splash in the vapor deposition process and can also effectively suppress the generation of particles. The mechanism of suppressing splash and particles will be described with reference to FIG.

  The present inventor estimates the behavior of the vapor deposition material in the vapor deposition film forming process using the SiO sintered vapor deposition material as shown in FIG. That is, in the vapor deposition film forming process using the SiO sintered vapor deposition material, the surface of the vapor deposition material is irradiated with heating energy such as plasma or electron beam. Thereby, SiO evaporates from the surface of the vapor deposition material, and an SiO film is formed on the surface of the target such as a substrate disposed opposite to the surface of the vapor deposition material 10.

At this time, in the vicinity of the surface of the vapor deposition material to which the heating energy is irradiated, a thermal decomposition reaction occurs in a part of SiO to generate SiO ₂ and Si. Si generated by the thermal decomposition reaction collects on the surface as the surface is consumed. This is because the vapor pressure of SiO, SiO ₂ , and Si decreases in this order, and evaporation does not easily occur in this order. That is, SiO ₂ and Si are generated by the thermal decomposition reaction, but SiO ₂ evaporates relatively easily, and Si hardly evaporates and remains easily. However, since SiO and Si react again and return to SiO and evaporate, the actual evaporation amount of SiO ₂ is not large. Si is also consumed by the re-reaction, but since the evaporation amount is small, it remains granular on the surface of the vapor deposition material. It is considered that the agglomerated Si particles remaining on the surface of the material cause a splash, and as a result, a particle. Actually, agglomerated Si particles that can be clearly confirmed visually remain on the surface of the vapor deposition material after use where film quality deterioration due to splash or particles has occurred.

  As can be seen, the film quality degradation caused by splash and particles is caused by Si in the vapor deposition material. This Si is generated not only in the vapor deposition process but also in the sintering process in the vapor deposition material manufacturing process. The low-temperature sintering described in Patent Document 3 reduces the amount of Si generated in the sintering process, but there are many secondary problems. Therefore, in the present invention, paying attention to the above reaction in the film formation process, the amount of O in the material is increased in the material manufacturing process. Then, Si that remains unreacted is oxidized by surplus O in the material, and the Si changes to an oxide, thereby preventing aggregation of Si particles on the material surface, and generation of splash due to the aggregated Si particles, Furthermore, the generation of particles is suppressed.

  As described above, the present inventor presumes the reason why the generation of splash and particles is effectively suppressed by the SiO sintered vapor deposition material of the present invention. Actually, when the deposited film is formed using the SiO sintered vapor deposition material of the present invention, no agglomerated Si particles are observed on the surface of the vapor deposition material after use.

Next, the effectiveness of the SiO sintered vapor deposition material of the present invention and the method for producing the vapor deposition material will be clarified by comparing with the case of the comparative material.

  Precipitated SiO produced by a vacuum aggregating apparatus (high-temperature precipitated SiO deposited in a high temperature region of 400 ° C. or higher at the outer surface temperature of the aggregating tube) was pulverized to an average particle size of 20 μm. The SiO powder was binder-molded into a tablet shape having a diameter of 30 mm and a height of 40 mm. The molded body was sintered at a low temperature in the air, and then sintered at a high temperature in an inert gas atmosphere (in an Ar gas atmosphere).

  For comparison reference, various sintering temperatures for low-temperature sintering and high-temperature sintering were used, and vapor-deposited materials that omit low-temperature sintering and vapor-deposited materials that omit high-temperature sintering were also manufactured. . The binder used in the molding process was commercially available, and the amount added was 20% by weight.

The oxygen quantitative analysis value O ₁ was determined for the manufactured SiO sintered vapor deposition material (tablet). The compressive fracture strength was also measured. The EPMA used was JEOL / JJA-8100, the analysis area was 42.5 mm square, and the analysis elements were O and Si.

  Moreover, the manufactured SiO sintered vapor deposition material (tablet) was actually used for the vacuum vapor deposition test (ion plating), and the splash resistance characteristic and the particle resistance characteristic of each material were investigated. The vapor deposition film forming conditions are shown in Table 1, and the investigation results are shown in Table 2 together with the manufacturing conditions. In the investigation of the splash resistance characteristics, the splash was detected and counted as the number of pinholes in the base film. In the investigation of particle resistance, the number of particles of 5 μm or more on the film was counted with a laser type particle counter. The film formation rate was expressed as a relative value with Comparative Example 1 using the vapor deposition material A as 100.

The vapor deposition materials A to C (Comparative Examples 1 to 3) are conventional materials in which only high-temperature sintering is performed in a non-oxidizing atmosphere. Since the low-temperature sintering is not performed in the atmosphere, the oxygen analysis value O ₁ is as small as less than 44 wt%. Since high-temperature sintering is performed in an Ar gas atmosphere, the compression fracture strength is high. Although the compressive fracture strength is high, both the number of pinholes and the number of particles are large because Si is precipitated during the high-temperature sintering process. The number of pinholes increases as the sintering temperature increases, and the number of particles decreases as the sintering temperature increases.

Although the vapor deposition material D (Comparative Example 4) was subjected to low-temperature sintering in the atmosphere before the main sintering, the oxygen quantitative analysis value O ₁ does not reach 44 wt% because the temperature is low. For this reason, in the deposited film forming process, the number of pinholes does not decrease and the number of particles is large due to the influence of Si deposited in the main sintering.

The vapor deposition materials E to G are examples of the present invention in which low temperature sintering at an appropriate temperature is performed in the air before the main sintering. The oxygen quantitative analysis value O ₁ satisfies 44 to 49 wt%, and the compressive fracture strength is 15 MPa or more. Despite the high temperature sintering at 1000 ° C., the number of pinholes is small. The number of particles is slightly higher because the sintering temperature is relatively low at 1000 ° C. although it is a high temperature sintering. As the temperature of the low-temperature sintering in the atmosphere increases, the oxygen quantitative analysis value O ₁ increases, and both the number of pinholes and the number of particles decrease. Since the temperature at the high temperature sintering is the same, the compression fracture strength is only slightly higher.

Since the vapor deposition material H (Comparative Example 5) has a high sintering temperature in the atmosphere, the oxygen quantitative analysis value O ₁ exceeds 49 wt%. Since the characteristics approach that of SiO ₂ whose vapor pressure is lower than that of SiO, the film formation rate is lowered, and productivity is adversely affected.

  The vapor deposition materials I and J are examples of the present invention in which low-temperature sintering at an appropriate temperature is performed in the atmosphere before the main sintering. Since the temperature of high-temperature sintering after low-temperature sintering is increased, the amount of Si in the material should have increased, but the number of pinholes is small. With the increase in the high temperature sintering temperature, the compression fracture strength has been greatly improved and the number of particles has been drastically reduced.

It is explanatory drawing of the manufacturing process of the silicon monoxide type vapor deposition material of this invention. It is a block diagram of the vacuum coagulation apparatus used for manufacture of a raw material (deposition SiO). It is an image figure which shows the principle of splash production | generation and suppression in a vapor deposition film formation process.

Explanation of symbols

1 Raw material chamber 2 Coagulation chamber

Claims (2)

  A ratio of the O / Si ratio a to the theoretical value a0 (≈1.14) when a standard sample made of SiO2 is quantitatively analyzed by EPMA. a / a0) is the correction coefficient K, and the actual measurement value A of the O / Si ratio by EPMA is obtained from the correction value A1 (= 1 / K · A) of the O / Si ratio obtained by correcting with the correction coefficient K. An SiO sintered vapor deposition material having an oxygen quantitative analysis value O1 [= 100 / (1 + 1 / A1)] of 44 to 49 wt% and a compressive fracture strength of 15 MPa or more.   The SiO sintered vapor deposition material according to claim 1, wherein the compressive fracture strength is 30 MPa or more.