JPH0452537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is an optical information recording medium capable of repeatedly recording, reproducing, erasing and rewriting information at high density using light and heat _. (O
The present invention relates to a method for manufacturing a thin film whose main component is <x<2), and provides an easy and reproducible method for manufacturing an optical information recording thin film.

Structure of the conventional example and its problems A thin film of TeO _x (O<x<2) is known as an optical information recording thin film with high sensitivity and high signal quality (Japanese Patent Publication No. 54-3725), and it has already been used. Still image files, document files, etc. have been commercialized.

In addition, this TeO _x (O<x<2) is the main component,
The technology to obtain a rewritable optical information recording thin film by adding additives to this is already known (Patent Application 1982-100626, Proceedings of the 30th Applied Physics Association Lectures in 1981). The materials used include selenium, sulfur, germanium, and tin.

These rewritable optical information recording thin films need to be used over and over again, and therefore have better uniformity and reproducibility in film composition than conventional recording thin films that can be recorded once (recorded only once). The gender is
stricter requirements.

Conventionally, the following methods have been used to add additives to TeO _x as the main component.

(1) Prepare sources of TeO ₂ and Te as main components and sources of Ge and Sn as additives, and simultaneously deposit on the substrate from multiple sources by controlling the heating temperature of each source, Contains additives
A method for synthesizing TeO _x (O<x<2).

This method allows TeO _x containing additives of arbitrary composition by independently controlling the heating temperature of each source.
Possible advantages include being able to obtain thin films and performing multiple evaporation processes in succession, but so far it has not been possible to control the evaporation rate because Te, for example, is a substance with extremely high vapor pressure. There were other problems, such as difficulty in reproducing the properties, insufficient reproducibility of characteristics, and the tendency to cause dropouts due to bumping.

(2) TeO ₂ source and additives such as Ge and Sn
A method of synthesizing TeO _x (O<x<2) containing additives by preparing alloy sources with Te, controlling the heating temperature of each source, and depositing the alloy onto a substrate.

This method is much simpler than method (1), and allows TeO _x to contain additives easily. However, if there is a difference in vapor pressure between Te and the additive, the composition of the evaporated material from the Te-based alloy source will change, creating a compositional shift in the thickness direction in the film, resulting in film properties. There was a problem of a decrease in performance or poor reproducibility.

(3) A method in which a raw material consisting of a mixture of TeO ₂ and a metal or metalloid substance as an additive is placed on a tungsten boat or a metal port with strong reducing power, such as a molybdenum port, and vacuum evaporated. (Tokugansho
53-100626, 58-58158) In this method, a metal port is energized and heated to cause a reduction reaction with TeO ₂ on the port surface, and evaporation is performed while removing some of the oxygen in TeO ₂ . The idea is to obtain TeO _x (O<x<2) and also incorporate additives at the same time. This method has the advantage of being able to obtain a TeO _x thin film containing additives very easily, but on the other hand, as the reaction progresses, the reducing power of the port surface decreases.
There were problems such as a deviation in the composition ratio of Te and O in the film thickness direction and difficulty in controlling the concentration of the additive material.

(4) In the method (3) above, instead of the metal port, a reducing material such as Fe, Cr, W, etc. is added in advance to the mixed powder of TeO ₂ and additives.
A method of mixing powders such as powders and vacuum evaporating them. (Japanese Patent Application No. 58-58158) In this method, the raw material is placed in a stable container such as a quartz crucible that does not easily react with the raw material, and the outer wall of the container is heated with a coil heater, etc. to combine TeO ₂ and the reducing material. A reduction reaction is caused in between, and TeO ₂ is vapor-deposited while removing some of the oxygen in TeO _x (O<x
<2) and also contain additives at the same time.

Compared to method (3), this method can improve reproducibility by preparing a large amount of raw materials in advance and dispersing them for use. Also, while there are advantages such as not having to replace the boat every time, as in the case of method (3), the amount of reducing agent decreases as the reaction progresses, and the composition ratio of Te and O in the film thickness direction Misalignment is unavoidable.

Purpose of the Invention The present invention provides reproducibility, controllability,
We provide a method to easily and reproducibly incorporate additives into TeO _x by solving problems such as uniformity.
The purpose of the present invention is to provide a new method for producing a rewritable optical information recording thin film mainly composed of TeO _x (O<x<2).

Structure of the Invention In order to achieve the above object, the present invention is characterized in that a mixture obtained through the steps described below is used as a deposition source.

(a) a step of mixing TeO ₂ and a reducing substance; (b) a step of heat-treating the mixture to cause a part of TeO ₂ to react with the reducing substance; (c) adding an additive material to the sintered body. The process of mixing.

According to the present invention, TeO ₂ generated by heat treatment
Most of the reduced form of combines with a part of the reduced metal to form the compound Te-M, leaving unreacted _TeO2 and
As a result of the reaction, it combines with oxidized Mo to form a uniform sintered body. During vapor deposition, the
TeO ₂ and Te removed from the Te-M bond are simultaneously deposited, and the main component TeO _x (O
< x < 2), but the method using this sintered body does not cause a rapid reaction compared to the method of vapor deposition while reducing, so there is no problem of the source boiling over, and it is also possible to Since the dissociation progresses gradually at a constant speed, there is little deviation in the composition in the film thickness direction. In addition, by creating a large amount of source at once and then using it in fractions, TeO _x films with the same characteristics can be obtained with much better reproducibility than other methods.

In addition, the additive material mixed in the sintered body is dispersed homogeneously in the sintered body, so that it is less likely to be separated from the main component TeO _x during vapor deposition.
It is homogeneously contained in the main component TeO _x thin film without major compositional deviation. Additive materials and vapor pressure of TeO _x ,
If the melting points are chosen close to each other, the additive concentration in the TeO _x thin film becomes more uniform.

DESCRIPTION OF THE EMBODIMENTS An example of a process for making a deposition source according to the invention is detailed below.

First, put TeO ₂ powder and a reducing substance in a mortar and mix well. A ball mill can also be used for mixing. Further, by adding and mixing alcohol, acetone, etc., it becomes easier to make the mixture uniform. After the mixed powder is dried, it is placed on a quartz boat and heat-treated in an electric furnace. N ₂ during heat treatment,
It is carried out in an inert gas atmosphere such as Ar. The heat treatment temperature varies depending on the reducing substance, but is approximately 400℃.
The reaction took place between 1000°C and 1000°C, and a clean sintered body was obtained. If the heat treatment temperature is below 400°C, the reaction will not proceed sufficiently, and if it is above 1000°C, a large amount of Te component will evaporate during the treatment, which is not preferable. Particularly between 600°C and 700°C, a clean sintered body with few evaporated components, good reproducibility, and sufficient reaction progress was obtained.

Reducing substances include Al, Si, Ti, V, Cd,
In, Sn, Sb, Ta, W, Cr, Mn, Fe, Co, Ni,
Metals or metalloids such as Cu, Zn, Ge, Mo, Bi, Pb, S, Se, C, etc. can be used. The above reducing substance reacts with TeO ₂ by heat treatment,
For example, a change shown in the formula mTeO ₂ +nM→TeM+MO+TeO ₂ occurs. i.e. _TeO2
A part of is reduced by a part of the reducing substance M.
Te becomes Te, and at the same time M takes O and MO,
It forms oxides such as M ₂ O ₃ and MO ₂ . At this time, most of the reduced Te is combined with the unreacted M, resulting in M ₂ Te, MTe, M ₂ Te ₃ ,
It takes the form of MTe ₂ and is contained in the sintered body.
Therefore, the sintered body obtained as a result of the heat treatment has M-
It can be said that it is an aggregate of Te alloy, M-O oxide, and TeO ₂ .

Among the reducing substances mentioned above, Cu, Sb, Pb, Al,
In, Zn, Bi, Ge, Se, and Cd not only reduced tellurium dioxide at an appropriate rate, but also had good compatibility with Te produced by reduction, and a uniform sintered body could be obtained. In particular, the elements Cu, Al, Sb, Pb, and In were found to have very high compatibility with Te, resulting in an extremely uniform sintered body.

The appropriate mixing ratio of the reducing agent was 15 mol% to 80 mol%. When the mixing ratio is less than 15 mol%, the reduction does not proceed sufficiently, and the low tellurium oxide thin film deposited using this sintered body is a film with a very high O content, as will be described later, and the light absorption coefficient is recorded as low. The front and rear optical changes were sufficient. Also, the mixing ratio is 80mol
% or more, the reduction progresses too much and the low tellurium oxide thin film deposited using this sintered body has a very low Te
The film contained many components and had thermally unstable characteristics, making it impossible to use it as an optical information recording film. When the mixing ratio is between 15 mol% and 80 mol%, a moderate amount of TeO ₂
It was found that a sintered body in which the reduction of was progressed was obtained, and that it was possible to obtain a tellurium low oxide thin film as the main component of an optical information recording medium with characteristics depending on the mixing ratio.

As a means for incorporating additives to improve or add functions to this sintered body, a method similar to the above-mentioned method of mixing a reducing substance with TeO ₂ is used.

Examples of additive materials include Ti, V, Ta, Cr,
Mo, W, Mn, Fe, Co, Ni, Pt, Cu, Ag,
Zn, Cd, Al, In, Tl, Si, Ge, Sn, Pb, As,
Metals, semimetals, and nonmetallic elements such as Sb, Bi, S, and Se can be used alone or in the form of oxides, or as a compound between each substance. Although the optimum amount of the additive varies depending on the additive, a deposited thin film with good recording properties and stability was obtained in the range of 10 to 40 wt%. As mentioned above, during vapor deposition, the additive is taken into the vapor deposited thin film and acts on the Te fine particles in TeO _x (O<x<2), for example, it combines with Te as a single element,
Te particles facilitate reversible phase transition.
Alternatively, it is thought that it exists around Te and acts to increase the thermal diffusion coefficient.

In order to satisfy the conditions such as increasing the homogeneity of the deposited film composition among the above-mentioned additives, or lowering the deposition temperature so as not to damage the base material,
a melting point as close as possible to the melting point and vapor pressure of TeO _x ,
Choose a material with vapor pressure. For this reason, especially
Zn, Cd, In, Tl, Ge, Sn, Pb, As, Sb, Bi,
S and Se were effective. Among them, Ge, Sn, Se,
When Bi, In, and Zn were used, vapor deposition was easy, and the resulting thin films had excellent recording properties.

When these additives are selected in amounts ranging from 10 to 30 wt%, a thin film with particularly excellent rewriting properties can be obtained. If the amount added is too large, the rewritability of the film will be lost. On the other hand, if the amount decreased too much, sufficient rewriting characteristics could not be obtained.

As mentioned above, it is possible to add it not only as a single substance but also in the form of oxide, nitride, halide, or carbide, but it is generally easier to evaporate and the reproducibility of characteristics is easier when added alone. It was expensive. However, the melting point, vapor pressure, etc. of telluride of these substances are very close to those of TeO _x (O<x<2) deposited from a sintered body, which is the main component, and are therefore more stable and stable. It was also found that a vapor deposition source with excellent reproducibility was obtained, and that the thin film deposited from this source had a more homogeneous film composition than when the additive was used alone. It was also discovered that even substances that are considered difficult to use alone can be used satisfactorily by combining them with tellurium. For example, Ti-Te, V-Te, Ta-Te,
Cr-Te, Mo-Te, W-Te, Mn-Te, Fe-
Te, Co−Te, Ni−Te, Pt−Te, Cu−Te, Ag
−Te, Zn−Te, Cd−Te, Al−Te, In−Te,
Tl-Te, Si-Te, Ge-Te, Sn-Te, Pb-Te,
As-Te, Sb-Te, Bi-Te, S-Te, Se-Te
Compounds such as can be used. Among them,
Ge−Te, Sn−Te, In−Te, Pb−Te, Sb−Te,
Se−Te, Zn−Te, Al−Te, Bi−Te, Cu−Te
When using Te-based compounds consisting of either alone or in combination, vapor-deposited thin films with extremely excellent recording and erasing properties were obtained.

It is also possible to use these Te-based compounds in combination with the above-mentioned elements alone or inter-element compounds. For example, Sn-Te, In-Te, Pb-Te, Sb
−Te, Se−Te, Zn−Te, Al−Te, Bi−Te,
The evaporation source that combines Cu-Te etc. and Ge is
It has been found that it is possible to produce a rewritable optical information recording thin film that is extremely stable, has good reproducibility, and has good characteristics.

The appropriate weight composition ratio of the additive in the mixture is 10 to 40 wt%. When telluride is used, a rewritable deposited film can be obtained with a relatively wide range of addition amounts, and even if the addition amount is slightly different, the characteristics do not change significantly, making it an extremely effective method for improving reproducibility. It was a method.

It is already known that Ge increases the crystallization temperature of Te in TeO _x (O<x<2) thin films and increases the thermal stability of the film (Proceedings of the 30th Applied Physics Association Conference).
1983). It was found that Ge added to the sintered body together with telluride was contained in the film with good reproducibility at a concentration that corresponded to the added concentration. For example, Sn−Te, In−Te, Pb−Te, Sb−
Te, Se−Te, Zn−Te, Al−Te, Bi−Te, Cu
When Ge was used in combination with -Te, etc., a recording thin film with excellent stability was obtained with good reproducibility in the range of 0 to 10 wt% of Ge. When the concentration of Ge added exceeds 10%, it was difficult to crystallize the film with a short pulse.

FIG. 1 shows a method of forming a TeO _x thin film containing an additive using the mixture deposition source obtained as described above. The vacuum degree of vacuum system 1 is
A temperature of about 10 ^-3 Torr to ^{10 -7} Torr is sufficient, but a strong film with high adhesion can be obtained at a pressure of 10 ^-5 Torr or less. For example, the mixture 2 is placed in a quartz container 3, heated from the outside with a coil heater 4, and a TeO _x thin film containing an additive is deposited on a substrate 6 placed on a support stand 5. A suitable heater temperature is 500°C to 1000°C, and the deposition rate and film composition can be controlled within this range. The coil heater 4 is connected to an external electrode 8 via an electrode 7, and has a mechanism for heating with electricity.

The mixture vapor deposition source can be produced in large quantities and then used in fractions to make it homogeneous and further improve reproducibility.

By annealing the mixture in an inert gas such as N ₂ or Ar, the components become more compatible and bumping during vapor deposition can be eliminated. However, if the annealing temperature exceeds the temperature at which the main component sintered body is fired, the characteristics of the sintered body will change, so it is necessary to set the annealing temperature slightly lower than the firing temperature. be.

As a heating method during vapor deposition, in addition to the method of heating the whole from the outside with a heater as described above, there is a method of rapidly heating locally using an electron beam. In this case, it is easier to heat the sauce by compacting the powder of the mixture and forming it into, for example, a disc-shaped pellet. Compared to the case of using a heater, the method using an electron beam makes it possible to (a) raise the temperature of the pellet rapidly and locally, and there is less compositional deviation than when heating the entire pellet with a heater; In addition to (b) the advantage that the response is fast and the deposition rate can be easily controlled, it was also found that (c) the moisture resistance is further improved as will be described later. Films made using a method that uses sintered bodies as the main raw material have a denser structure than films made using other methods, and are therefore thought to be less susceptible to the effects of outside air. However, thin films made using an electron beam The membrane structure is more dense and homogeneous, and it is hardly affected by the outside air, so it is thought that humidity deterioration is small.

Next, the present invention will be explained using more specific examples.

Example 1 Using TeO ₂ powder and Cu powder as starting materials, 111.72 g (about 0.7 mol) of TeO ₂ and 19.68 g of Cu
(approximately 0.3 mol) using a small amount of alcohol. Mixed powder 100g
was placed on a quartz boat and heat treated using an electric furnace. Put the sample into the furnace core tube, raise the temperature of the furnace while flowing _N2 gas at about 2/H, and heat it for about 30 minutes.
After the temperature was set to 700°C and maintained for about 2 hours, the sample was taken out to the low temperature section of the furnace and cooled. After about 1 hour, when taken out from the furnace, a black-colored glassy solid was obtained.

This solid material was taken out from the quartz boat, and a portion thereof was used for vapor deposition using the system shown in FIG.
The degree of vacuum is 1×10 ^-5 Torr, the heater temperature is 700℃,
When about 200 mg of the solid substance was placed in a quartz container and heated, a transparent TeO _x thin film with a thickness of about 1200 Å and a slightly yellowish cutlet color was formed on the acrylic resin substrate. λ=830 for this thin film
It was confirmed that when the semiconductor laser beam of mm diameter was focused using an optical system and irradiated, the irradiated area was transformed into black.

Example 2 A powder obtained by crushing the solid obtained in Example 1,
The weight ratio of Sn powder is 0, 5, 10, 20, 30, 40,
After mixing at a ratio of 50%, vapor deposition was performed using the system shown in Figure 1. The degree of vacuum was 1 × 10 ^-5 Torr, the heater temperature was 750°C, and 300 mg of each of the above powders was placed in a quartz container.
When heated, a yellow transparent thin film with a film thickness of 800 to 1200 Å was formed in the acrylic resin base material. When this thin film was irradiated with semiconductor laser light of λ = 830 nm using an optical system with a slightly loose focus and irradiated with a weak light of about 1 mW/μ ² for 1 μsec, the thin film turned black. Next, using the same semiconductor laser beam and focusing on the blackened transformation area, we irradiated it with a strong intensity of about 5mW/ ^μ2 for about 50μsec, and the film with Sn addition amount of 5 to 40wt% showed black transformation. It was confirmed that the part returned to its original yellow color. However, if the amount added was less than 5%, the original state could not be completely restored, and if it exceeded 40%, there was no reversibility at all. A detailed study of the transmittance, reflectance, etc. of the film after restoration revealed that reversible changes occurred repeatedly when the amount of Sn added was in the range of 10 to 30 wt%.

Example 3 In Example 1, the mixing ratio of Cu was 0 to 100 mol%
As a result of conducting a similar experiment with the mixture ratio between 0 and 90 mol %, uniform black sintered bodies were obtained. Example 1 using this sintered body
When the mixture ratio was between 0 and 15 mol %, the optical density of the film was very low, and even when irradiated with semiconductor laser light, no large change in concentration was obtained. In addition, when the mixing ratio exceeds 80 mol%, the optical density increases, but the film is unstable. Immediately after vapor deposition, it is a cut-colored transparent film, but it gradually changes at room temperature and becomes slightly opaque. It turned into a metallic black film. Mixing ratio is 15~
Between 80 mol% and 80 mol%, a stable cutlet-colored transparent film with a yellowish tinge was obtained, which was transformed into black by semiconductor laser light.

Composition analysis using Auger electron spectroscopy revealed that the film was homogeneous with almost no compositional deviation in the thickness direction.
It was also found that the O/Te value decreased from low to high mixing ratios.

Example 4 A similar experiment was conducted in Example 1 using Al instead of Cu and the mixing ratio ranged from 0 to 100 mol%. A sintered body was obtained. As a result of vapor deposition using this sintered body in the same manner as in Example 1, the mixing ratio was 0 to 0.
When the optical density was between 20 mol % and 20 mol %, the film had a very low optical density, and no large change in concentration could be obtained by irradiation with semiconductor laser light. Also, the mixing ratio is 60mool%
Above this value, the optical density increases, but the film is somewhat unstable, changing from a cutlet color to black at room temperature. When the mixing ratio was between 20 and 60 mol%, a stable yellow film was obtained, which transformed to black when irradiated with semiconductor laser light. As a result of compositional analysis using Auger electron spectroscopy, it was found that the O/Te ratio changes sensitively to the concentration of Al added.

Example 5 Instead of Cu powder, Si, Ti, V, Cd, In, Sn,
Sb, Ta, W, Cr, Mn, Fe, Co, Ni, Zn, Ge,
Examples 1 and 2 using each element of Mo, S, Se, and C
We conducted similar experiments and were able to obtain sintered bodies in each case. Among these, Sb, Pb, In, Zn, Bi,
When using Ge, Se, and Cd, black, yellow cutlet color, black cutlet color, black, gray cutlet color, yellow cutlet color,
A glassy, homogeneous sintered body with a reddish or grayish color was obtained. Especially when using Sb, Pb, and In, Cu
As in the case of , homogeneous glass-like sintered bodies could be obtained over a wide range of mixing ratios. On the contrary, Si,
When C and Mn were used, only a slightly non-uniform sintered body was obtained.

By heating these sintered bodies in vacuum, each
A TeO _x (O<x<2) thin film was obtained.

Example 6 Next, TeO _x to be obtained using multiple reducing substances
We investigated methods for finely controlling the properties of thin films. The reducing substances mentioned in Example 5 do not all have the same reducing ability, and MO ₂ or
There are two types: those that are oxidized and undergo a violent reaction with a relatively high reducing ability, such as M ₂ O ₃ , and those that are only oxidized and have a relatively low reducing ability, such as MO and M ₂ O, that undergo a gentle reaction. . Therefore, fine control can be achieved by combining the two. As a result of Example 4, it was found that Al is particularly easy to use as a representative of the former, and Cu is particularly easy to use as a representative of the latter.

Therefore, TeO ₂ was mixed with Au and Cu at different mixing ratios, and each was heated at 700℃ for 2 hours in a N ₂ gas atmosphere.
A black sintered body was obtained by heat treatment. As a result of heating 200 mg of each of these sintered bodies with a heater at a vacuum level of 10 ^-5 Torr, a film with characteristics that corresponded to slight changes in the mixing ratio was obtained. We investigated this result in detail by irradiating it with a semiconductor laser, and determined the Al mixing ratio x〓 and
Cu mixing ratio x〓 is 15x〓50, and 20≦x〓≦
60 mol%, and when the two components are mixed at the same time, a thin film particularly suitable for optical information recording properties can be obtained in the region of 50≦x〓＋x〓≦80mol%, and it is suitable as a base material for the mixture. I understand.

Example 7 Among the sintered bodies obtained in Example 6, the starting composition was
A sintered body containing (TeO ₂ ) ₃₀ (Al) ₃₀ (Cu) ₄₀ mol % was selected and crushed to form a fine powder. Additives to this powder include Ti, V, Ta, Cr, Mo, W, Mn, Fe,
Ni, Pt, Cu, Ag, Zn, Cd, Al, In, Tl, Si,
Ge, Sn, Pb, As, Sb, Bi, S, Se each in the form of a single substance or oxide, 5% by weight in the range of 0 to 50wt%.
When the same experiment as in Example 2 was carried out by mixing each percentage, it was found that in the case of a single substance, the amount added was 10 to 10%.
A yellowish thin film was obtained that was rewritable at 40 wt%, and in the case of oxides in the range of 20 to 60 wt%. Among these, Zn, Cd, In, Tl, Ge, Sn, Pb, As, Sb,
When Bi, S, and Se were used alone, they were compatible with the sintered body, which is the main component of the source, and the heater temperature during vapor deposition was close, making it possible to obtain a uniform vapor-deposited film. Particularly when using a mixed evaporation source using Ge, Sn, Se, Bi, In, and Zn, the heater temperature
A temperature of 400°C to 700°C was sufficient and vapor deposition could be performed easily and with good reproducibility. When the amount added was in the range of 10 to 30 wt%, a thin film with particularly excellent repeatability was obtained.

On the contrary, Ti, Fe, Co, Ta, Ni, Pt, W, Cr
When using materials with relatively low vapor pressure such as, it was difficult to form a uniform film with the sintered body as the main component.

Example 8 Tellurides of various elements were investigated as additives. As a sintered body, the starting composition is (TeO ₂ ) ₃₀
(Al) ₃₀ (Cu) ₄₀ mol% was sintered in the same manner as in Example 1.

TeSm was used as the telluride and mixed well with the sintered body at a mixing ratio of 0 to 50 wt%.
Weigh out about 2g of this powder and use a jig to
It was press-formed into a pellet-like object with a thickness of approximately 1.5 mm. Press pressure is 5t/ ^cm2 . When this pellet was heated with an electron beam with an output of 5KW in a vacuum of 1 x 10 ^-5 Torr using the system shown in Figure 1, a very homogeneous thin film with a thickness of about 1000 Å was formed at a rate of 10A/S. could be formed on an acrylic resin base material. When the properties of this thin film were measured using a semiconductor laser and an optical system while changing the power of the irradiation light and the irradiation time, a thin film with excellent repeatability was obtained over a wide range of additive amounts of 10 to 40 wt%. It was found that when the content is less than 10%, sufficient rewriting characteristics cannot be obtained, and on the other hand, when it exceeds 40%, the film becomes extremely terich and the stability of the film decreases.

Example 9 As telluride, Ge-Te, Sn-Te, In-
Te, Pb-Te, Sb-Te, Se-Te, Zn-Te, Al
When we conducted the same experiment as in Example 7 using -Te, Bi-Te, and Cu-Te, we found that 10 to 40 wt.
A vapor deposition source capable of forming a rewritable film with easy vapor deposition and good reproducibility was obtained in the additive concentration range of 1.5%.

Example 10 Differences in characteristics due to differences in heating methods were observed.
In Example 8, the mixing ratio of TeSn was chosen to be 20 wt%, and one part was deposited on a Pyrex glass substrate by heater heating in the system shown in Figure 1, and the other part was deposited on a Pyrex glass substrate by electron beam heating. A slightly darkish thin film was obtained that did not change. Two types of NONO's membranes were left in a constant temperature and humidity chamber at 50℃ and 90H%, and changes in their transmittance were periodically examined.
As shown in the figure, it was found that the film b produced by the electron beam showed less change than the film a produced by heater heating, was less affected by moisture, and was more stable.

Next, by using multiple additive substances,
We investigated a method to finely control the properties of recording thin films containing TeO _x as the main component. The additive substances described in Examples 7 and 9 do not have constant deposition characteristics or behavior in the film, such as substances that increase the phase transition temperature or substances that work to shorten the irradiation time required for phase transition. etc.

Example 11 Using Sn-Te as a component that enhances the rewriting function and Ge as a component that promotes film stabilization, vapor deposition was performed in the same manner as in Example 7 by changing the amount of each addition, and the amount of addition was 10 to 40 wt%. We obtained a highly stable thin film that can be rewritten in the region of . Especially in the 15 to 30 wt% range, the repeatability was particularly good, and we were able to confirm recording and erasing 100,000 times.

FIG. 3 shows the change in blackening transition temperature when the amount of TeSn added is 20 wt% and the amount of Ge added is changed. When the amount of Ge added is 8wt%, the transition temperature is as high as about 200℃, and a considerably high laser power is required for the transition, and when the amount of Ge added is 10wt%, it is 240℃.
This was even higher, and it was difficult to transfer in a film with further addition of Ge.

Example 12 SnTe in Example 11 was replaced with InTe, PbTe,
Sb ₂ Te ₃ , SeTe, ZnTe, Al ₂ Te ₃ , Bi ₂ Te ₃ ,
We were able to obtain the same effect by rewriting Cu ₂ Te and depositing it.

Example 13 Next, an optical recording disk was prototyped using this vapor deposition method. Recording/erasing experiments were conducted using the system shown in FIG. First, the light from the semiconductor laser 11 is applied to the disk surface 10, which rotates at 1800 rpm, using the lens system 12, mirror 13, and lens 14, so that the spot intensity distribution is half the value and the disk rotation direction is
Laser spot 1 condensed to 10μ and 1μ in the radial direction
When 5 was irradiated with a total power of 10 mW, the irradiated area turned black and a black track 16 was formed.

Next, the light from another semiconductor laser 21 was focused through another lens system 17, a mirror 18, a half mirror 19, and a lens 20 onto a circular spot 22 of 0.8 μm, which was narrowed down to its wavelength of 830 μm. While modulating this laser spot 22 with a single frequency of 5MHz and a total power of 8mW, the black track 1 above is
When the top of 6 was irradiated, the irradiated area recovered to its original state and a bit group 23 was formed by recording the signal.

To detect the signal, the reflected light 24 from the disk is
The light is collected by the reproduction lens system 25 and sent to the detector 2.
Enter 6 and read. When the C/N was measured using a spectrum analyzer, a C/N of 58 dB was obtained.

Next, when the first elongated laser spot 15 was irradiated, the recorded bit 23 was erased and the spectrum analyzer could no longer detect the signal.

Effects of the Invention As described above, according to the present invention, (1) Excellent reproducibility of characteristics (2) Composition deviation is less likely to occur (3) There is no drop-out due to bumping (4) Humidity deterioration is small ( 5) A method for incorporating additives into a TeO _x thin film, which has characteristics such as controlled properties and easy vapor deposition, has been obtained, and a rewritable optical information recording thin film can be easily obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an apparatus for producing a TeO _x based thin film using a sintered body in one embodiment of the present invention, and FIG.
The figure is a graph showing the difference in moisture resistance due to the different vapor deposition methods of TeO _{x -based} thin films.
A diagram showing the change in blackening transformation temperature when adding
FIG. 4 is a schematic diagram of an apparatus for recording, reproducing, and erasing information signals on an optical disk formed by the manufacturing method of the present invention. 1...Vacuum system, 2...Mixture, 6...Substrate.

Claims (1)

[Claims] 1 Al, Si,
Ti, V, W, Cr, Mn, Fe, Co, Ni, Cu, Zn,
By mixing at least one of Ge, Mo, Cd, In, Sn, Sb, Ta, Bi, Pb metals, semimetals, or S, Se, and C, (TeO ₂ )100−x〓 ^M x〓( O＜x〓
80 mol%, M is an aggregate of reducing substances M ₁ , M ₂ , ..., _Mo , and heat treatment is performed in the form x ₁ + x ₂ + ... + x _o = x〓), and part of the tellurium dioxide is reduced. A sintered body N containing the sintered body N is obtained, a mixture P is formed by adding an additive material L to this sintered body N as a main material, and this mixture P is heated in a vacuum as a vapor deposition source. A method for producing an optical information recording thin film, which comprises forming an optical information recording thin film containing TeO _x (O<x<2) as a main component and an additive on a substrate. 2. The method for producing an optical information recording thin film according to claim 1, characterized in that the amount of the reducing substance added is 15 x 80 mol%. 3 As reducing substances, Cu, Sb, Pb, Al, In,
A method for producing an optical information recording thin film according to claim 1, characterized in that at least one reducing substance selected from Zn, Bi, Ge, Se, and Cd is used. 4 Select Cu as the reducing substance and its composition ratio x〓
15. The method for producing an optical information recording thin film according to claim 1, wherein x satisfies 15≦x≦80 mol%. 5 Select Al as the reducing substance and its composition ratio x〓
15. The method for producing an optical information recording thin film according to claim 1, wherein x satisfies 15≦x≦60 mol%. 6. The method for producing an optical information recording thin film according to claim 1, characterized in that Cu and Al are selected as reducing substances and mixed at the same time. 7 The composition ratios x〓 and x〓 of Al and Cu are each 15≦
The method for producing an optical information recording thin film according to claim 6, characterized in that x≦50, 20≦x≦60, 50≦x〓+x≦80 mol%. 8. The method for producing an optical information recording thin film according to claim 1, wherein the heat treatment is performed in an inert gas. 9. The method for producing an optical information recording thin film according to claim 1, wherein the heat treatment temperature is between 400°C and 1000°C. 10. The method for producing an optical information recording thin film according to claim 1, wherein the heat treatment is carried out at a temperature between 600°C and 700°C. 11. The method for producing an optical information recording thin film according to claim 1, characterized in that the degree of vacuum is set to about 1×10 ⁻⁵ Torr or less. 12 As the additive material L, Ti, V, Ta, Cr,
Mo, W, Mn, Fe, Co, Ni, Pt, Cu, Ag,
Zn, Cd, Al, In, Tl, Si, Ge, Sn, Pb, As,
Sb, Bi, S, Se metals, semimetals, nonmetallic elements,
At least one type used alone or as a compound,
The method for producing an optical information recording thin film according to claim 1, characterized in that the total amount x〓 of the added amounts is selected to be 10x〓40wt%. 13 The additive materials L include Zn, Cd, In, Tl,
At least one substance from the substance group consisting of Ge, Sn, Pb, As, Sb, Bi, S, and Se, alone or as a compound.
Using different types, the total amount of addition x〓 is 10x〓40wt
Claim 12, characterized in that
A method for producing an optical information recording thin film as described in 2. 14 As additive material L, Ge, Sn, Se, Bi,
At least one substance from the substance group consisting of In and Zn is used alone or as a compound, and the total amount x〓
The method for producing an optical information recording thin film according to claim 9, 10, or 13, characterized in that 10x=30wt% is selected. 15 As the additive material L, Ti-Te, V-Te,
Ta-Te, Cr-Te, Mo-Te, W-Te, Mn-
Te, Fe−Te, Co−Te, Ni−Te, Pt−Te, Cu
−Te, Ag−Te, Zn−Te, Cd−Te, Al−Te,
In-Te, Tl-Te, Si-Te, Ge-Te, Sn-Te,
Pb-Te, As-Te, Sb-Te, Bi-Te, S-Te,
Consists of Se-Te. Using Te-based compounds alone or in combination, the total amount x〓 of the added amount is 10x〓
A method for producing an optical information recording thin film according to claim 1, characterized in that the content is selected to be 40 wt%. 16 Ge-Te, Sn-Te, In as additive materials
−Te, Pb−Te, Sb−Te, Se−Te, Zn−Te,
Using T _e- based compounds consisting of Al-Te, Bi-Te, and Cu-Te, either singly or in combination, the total amount added
16. The method for producing an optical information recording thin film according to claim 15, characterized in that x〓 is selected to be 10x〓40wt%. 17 As additive materials, Sn-Te, In-Te, Pb-
Te, Sb-Te, Se-Te, Zn-Te, Al-Te, Bi
-Te, Cu-Te. At least one Te-based compound is used alone or in combination, and Ge
and the total amount of addition x〓, 10x〓40wt
%, of which the amount of Ge added is selected to be O<x〓≦10wt%. 18. The method for producing an optical information recording thin film according to claim 17, characterized in that 15≦x〓30 and O<x〓8wt%. 19. The method for producing an optical information recording thin film according to claim 1, characterized in that the mixture P is press-molded into pellets. 20. The method for producing an optical information recording thin film according to claim 1, characterized in that an electron beam is used as a heating means for the mixture P. 21. The method for producing an optical information recording thin film according to claim 1, wherein the mixture P is annealed in an inert gas and then used as a vapor deposition source. 22. The method for producing an optical information recording thin film according to claim 21, wherein the annealing temperature is set lower than the sintering temperature.