JP3449208B2 - Amorphous carbon nitride composition and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an amorphous carbon nitride composition that can be used as an electronic material in the field of electronic devices, and a method for producing the same.

[0002]

2. Description of the Related Art .beta.-C which is a crystal of a carbon nitride composition.₃
N_FourHas a hardness, thermal conductivity, and
It is predicted to have a product elastic modulus, sound velocity, etc.
It is one of the materials that has high expectations. But now
Is still single crystal β-C₃N _FourHas not been obtained,
Data such as physical properties, electrical properties, and optical properties of
The fact is that it has not been used and has not been practically used.
Is.

On the other hand, since a carbon nitride composition having an amorphous structure can be produced relatively easily as compared with a crystalline body, research and development have been carried out in various places and utilized. Here, the amorphous carbon nitride composition is generally formed by the plasma CVD method like the amorphous silicon and the amorphous carbon, and the hydrocarbon gas such as methane gas, ethane gas, and ethylene gas as the source gas, the nitrogen gas, the ammonia, and the like. A mixed gas with a gas containing nitrogen is used. It has been confirmed that the amorphous carbon nitride composition formed by the plasma CVD method has high hardness and high thermal conductivity, is excellent in stability, moisture resistance, chemical resistance, wear resistance and the like and has no magnetic property. Various materials, structures, tools,
It has been proposed to be used as a coating material for surface protection of electronic devices and magnetic devices.

By the way, there are various electronic materials used in the field of electronic devices depending on electrical characteristics, optical characteristics, and the like. Hereinafter, electronic materials such as photoconductive materials, insulating materials, light emitting materials, and cold cathode materials will be described. (1) The photoconductive material has photoconductivity (a characteristic that the conductivity of an insulator material or a semiconductor material is increased by irradiation of light,
A material having a photoconductive cell or a photodetector to which the photoconductive cell is applied, which is a phenomenon that occurs when electrons are excited from a valence band or an impurity level by light absorption to generate conduction electrons or holes. , An optical amplifier, an image pickup tube, an image pickup element, or the like, or an electrophotographic photoconductor or a copying machine or a printer to which the electrophotographic photoconductor is applied. Also,
By forming an interface having a barrier electric field such as a pn junction or a Schottky junction in a semiconductor having photoconductivity,
A photovoltaic cell that can generate a photovoltaic effect, a photovoltaic cell that uses the photovoltaic effect, a solar cell that applies the photovoltaic cell, an illuminometer, a photodetector, a photodiode, a phototransistor, an image sensor, etc. Can be realized.

Conventionally, as photoconductive materials, single crystal or polycrystal selenium, cadmium sulfide, cadmium selenide, cadmium telluride, lead sulfide, lead selenide, lead telluride, germanium, tellurium, indium antimony,
Indium arsenide, etc., chalcogenide-based amorphous materials such as selenium, selenium-tellurium, selenium-arsenic, selenium-arsenic-tellurium, etc. having an amorphous structure, and tetrahedral hydrogenation such as silicon, silicon-carbon, silicon-germanium, etc., having an amorphous structure. Amorphous silicon materials and / or organic pigments such as phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, and organic semiconductor materials such as cyanine dyes and various dyes such as squarylium dyes are used.

(2) The insulating material is a material having an electrical insulating property, and as electronic devices, especially semiconductor devices, are highly integrated, various functional elements and electrodes formed on the same substrate, and In order to electrically insulate and protect the element surface, and to control electrons and holes with an electric field from an external electrode, between elements and between electrodes, between the element surface and the electric field control electrode and the controlled structure. Therefore, an insulating material for ensuring electrical insulation has become important.

Silicon oxide, silicon nitride, aluminum oxide, tantalum oxide and the like are used as insulating materials used in semiconductor devices. (3) The optical property of the light emitting material has luminescence. Luminescence is a phenomenon of emitting light when an excited electron returns from its ground state to an original state by applying an electric field or light, and a material having this property can be used as a light emitting material. In particular, luminescence by electric field excitation (electroluminescence: commonly called EL) can be applied to a display device, lighting, and the like. Light emitting devices utilizing EL include a current injection type (injection EL) type and a voltage excitation type (intrinsic EL) type. The former is a light emitting device that utilizes a pn junction of a semiconductor and utilizes recombination of electrons and holes that are injected when forward biased, and is generally called a light emitting diode. Compound crystal mixed crystal semiconductors such as single-crystal gallium arsenide, gallium phosphide, and gallium nitride, which are direct transition semiconductors, are mainly used. On the other hand, the latter is one in which electrons in a light-emitting material are made to have high energy by utilizing a high electric field, and the electrons in atoms serving as emission centers existing in the light-emitting material are excited by the electrons to emit light. A thin film material having a polycrystalline or amorphous structure is used for, and a large area light emitting device can be easily manufactured by the thin film forming technique compared to the former.

As other light emitting materials, inorganic thin film materials such as zinc sulfide or zinc selenide to which manganese or a rare earth fluoride is added, or strontium sulfide or strontium gallium sulfide to which cerium is added, Organic thin film materials such as chelate metal complexes typified by aluminum quinolinol complexes are used. (4) The cold cathode material is, for example, a material used for a so-called vacuum microelectronic device, which is one of the electronic devices that has been attracting attention in recent years. Since vacuum microelectronic devices utilize electrons that travel in vacuum, they have the potential to realize high-speed functional devices that surpass conventional solid-state devices, and are lightweight, thin, and flat large-screen display devices that can replace cathode ray tubes. Alternatively, there is a possibility that it can be used for a thin flat type lighting device that replaces a fluorescent lamp. Such a vacuum microelectronic device is provided with an emitter for electron emission, and in particular, a field emitter array in which a small number of field emitters capable of field emission of electrons from the surface and a large number of field emitters are arranged in the same plane are used. ing. This field emitter has a high electron emission rate, can secure mechanical stability and chemical stability against the spattering phenomenon and surface contamination of the emitter surface, and also has a thermal problem caused by local current flow. Since it is necessary to have a high thermal conductivity to prevent this, a cold cathode material coating is applied to the emitter surface formed of silicon or a metal material. Conventionally, diamond, diamond-like carbon and the like have been used as cold cathode materials having such characteristics.

[0009]

By the way, the above-mentioned conventional electronic materials have the following problems. (1) Among conventional photoconductive materials, single crystal or polycrystalline selenium, cadmium sulfide, cadmium selenide, cadmium telluride, lead sulfide, lead selenide, lead telluride, germanium, tellurium, indium antimony, indium arsenide Etc., and chalcogenide-based amorphous materials such as selenium, selenium-tellurium, selenium-arsenic, and selenium-arsenic-tellurium having an amorphous structure, cadmium, lead, selenium, tellurium, arsenic, and antimony that are harmful or dangerous to the human body and environment. Therefore, there is a problem that special management, measures, and costs are required so that the human body and the environment are not affected at the time of manufacturing or disposal. In addition, many of these materials have relatively low hardness (relatively soft), including chalcogenide-based amorphous materials, and their surfaces are in contact with other materials, as in electrophotographic photoreceptors. In a sliding application, there is a problem that the service life is very short because the wear occurs immediately.

In addition, a tetrahedral hydrogenated amorphous silicon material such as amorphous silicon, silicon-carbon, silicon-germanium, etc., is used as a raw material gas for producing silane gas, methane gas, germane gas, and phosphine gas in the plasma CVD method. Since mixed gas such as diborane gas is used, there is a problem that the equipment and materials are special and expensive, and the cost of safety measures including exhaust gas treatment equipment is high. Although these materials are not as good as chalcogenide-based amorphous materials, they are not sufficiently wear-resistant to be applied to electrophotographic photoreceptors, and a protective film such as silicon nitride is formed on the surface of hydrogenated amorphous silicon materials. It had to be formed separately. In addition, in application to electrophotographic photoreceptors, the lower the conductivity without light irradiation, that is, the lower the dark conductivity, the better the charging performance and the less blurring of the image due to the flow of charges. Since the dark conductivity of the tetrahedral hydrogenated amorphous silicon material is relatively high at 10 ^-11 S / cm to 10 ^-13 S / cm, the film thickness is 1 for use as an electrophotographic photoreceptor.
It is necessary to make the thickness 0 μm to 20 μm, and there is a problem that the time required for film formation becomes extremely long. Further, there is a problem that the organic semiconductor material is not sufficient in stability and durability as compared with the inorganic semiconductor material.

(2) Among conventional insulating materials, silicon nitride, aluminum oxide, tantalum oxide and the like have relatively large relative permittivity values of 6 to 20, so these materials are used for semiconductor devices and the like. Then, the inter-element capacitance and inter-electrode capacitance increase, which may cause a problem in a device that requires high-speed operation. Also,
Although silicon oxide having a relative dielectric constant of 4 or less can be obtained depending on the manufacturing method, there is a problem in that the moisture resistance is inferior to that of silicon nitride. In addition, the production of these insulating materials requires high temperatures (several hundreds of degrees Celsius or higher), and
Since it is necessary to use toxic gases such as silane gas, dichlorosilane gas, and ammonia gas as the raw material gas, there is a problem that the equipment including safety measures becomes expensive.

(3) Among conventional light emitting materials, a single crystal compound-based mixed crystal semiconductor, which is a material for injection type EL, is
It is difficult to increase the area of the device with the current technology, and it requires very expensive equipment such as MOCVD equipment and MBE equipment for crystal growth, as well as expensive and dangerous raw materials. There was a problem. On the other hand, the true E
The material for L has the advantage that it can be formed into a film using a relatively inexpensive device such as a sputtering device or a vacuum vapor deposition device, and can be formed relatively easily over a large area. There is a problem that many of them are highly toxic and it is necessary to use rare and expensive elements such as rare earths. Further, since the emission wavelength of the intrinsic EL material is determined by the base material in the light emitting material and the atom at the emission center, it is difficult to freely change the emission wavelength by material design. Further, in the case of the organic thin film material, there is a problem that stability and reliability are not so high and life is short.

(4) Further, in the field emitter which is an application example of the cold cathode material, the conductivity of the region functioning as the emitter is increased so that the electron emission is generated only from a specific region, and the region not functioning as the emitter. It is designed to have an insulator on the surface of, but in the case of conventional cold cathode materials such as diamond and diamond-like carbon, the control of electrical conduction (valence electron control) is performed by the method of doping impurities. In addition, the current technology has realized only p-type control, and it is difficult to control electric conduction as a field emitter, and there is a problem that the region functioning as a field emitter cannot be freely controlled. .

In order to solve the above problems of conventional electronic materials, various materials have been researched and developed in various places. On the other hand, a carbon nitride composition having an amorphous structure (hereinafter referred to as an amorphous carbon nitride composition) is
As described above, it is known that it has high hardness and high thermal conductivity, is excellent in stability, moisture resistance, chemical resistance, wear resistance, and has no magnetic property. It is attracting attention as an alternative to the electronic materials of. However, there are few reports on the electrical properties and optical properties of conventional amorphous carbon nitride compositions, and only a ratio of photoconductivity to dark conductivity (photoconductivity / dark conductivity) of about 3 digits is obtained. However, it was lower than the ratio of photoconductivity and dark conductivity in amorphous silicon by one digit to two digits. Further, the conventional amorphous carbon nitride composition has a high dark conductivity of about 10 ⁻¹³ S / cm, which is not sufficient as a photoconductive material or an insulating material used for an electrophotographic photoreceptor. Furthermore, since the conventional amorphous carbon nitride composition is produced by plasma CVD method or the like using a hydrocarbon gas such as methane gas, ethane gas, ethylene gas or the like as a raw material gas, a toxicity of the raw material gas, an explosion, etc. There was a manufacturing risk.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an amorphous carbon nitride composition that can be used as an electronic material and a method for producing the same.

[0016]

Claims 1 to 3
In order to achieve the above object, the invention of (1) is a carbon atom having an amorphous carbon nitride composition in which the localized density of states based on π bonds in the energy band structure is small and the expanded state density due to σ bonds is more predominant. And hydrogen plasma treatment on the surface so that there is a region composed of nitrogen atoms
In this region, electrons and holes generated by light irradiation are less likely to be trapped in a localized state, which contributes to conduction. Since the increase in carriers in the band in the spread state due to the coupling becomes large, the change in the conductivity due to the light irradiation becomes large as a result. In addition, as the localized state based on π bond becomes smaller, the optical gap and mobility gap become substantially larger, the Fermi level also moves near the center of the gap, and the number of carriers trapped in the localized state is also increased. Therefore, the number of carriers moving from the localized state to the band in the spread state is reduced, and the dark conductivity is reduced. Therefore, since the region where the change in conductivity due to light irradiation is larger than that in the conventional case and the dark conductivity is smaller than that in the conventional case exists in the amorphous carbon nitride composition, the photoconductivity and the dark conductivity also exist in the composition as a whole. The ratio with the ratio becomes larger than that of the conventional one, and good photoconductivity can be obtained, and the dark conductivity can be made smaller than that of the conventional one. In addition, when the entire composition is made of carbon and nitrogen atoms in which the localized density of states based on the π bond is reduced and the spread state density due to the σ bond is more dominant, The properties of the entire composition can be improved.

Furthermore, the invention of claim 1, have a greater characteristic than the ratio of 3-digit and photoconductivity and dark conductivity at room temperature
However, it is used as a photoconductive material, and the optical band gap is set to 1. by changing the composition ratio of carbon and nitrogen.
By varying in the range of 5 eV to 3.0 eV,
It can have sensitivity and transparency in the visible to near-infrared region, has high hardness and high thermal conductivity, and has excellent stability, moisture resistance, chemical resistance, abrasion resistance, and photoconductivity. Since the ratio of dark conductivity is large and the dark conductivity is small, a photoconductive cell, a photodetector using the photoconductive cell, an optical amplifier, an image pickup tube or an image pickup device, a photovoltaic cell or a photovoltaic cell, etc. There is a possibility of application to various applications utilizing photoconductivity such as solar cells, illuminometers, photodetectors, photodiodes, phototransistors, image sensors, etc. In particular, when used as an electrophotographic photoreceptor, the photoreceptor has excellent wear resistance and low dark conductivity, so that a high-performance and long-life photoreceptor in which an image does not flow even if the film thickness is reduced A drum can be realized, and by extension, a high-performance and long-life copier or printer to which the photosensitive drum is applied can be realized.

Further, the invention of claim 2 has at least one of a characteristic that the dark conductivity at room temperature is smaller than 1 × 10 ⁻¹³ S / cm and a characteristic that the relative dielectric constant is 6 or less.
And has an optical band gap of 1. by changing the composition ratio of carbon and nitrogen.
By varying in the range of 5 eV to 3.0 eV,
It has transparency in the visible to near-infrared region, has high hardness and high thermal conductivity, and has excellent stability, moisture resistance, chemical resistance, and abrasion resistance. Since it is possible to obtain a material having a dark conductivity or a relative dielectric constant value of 6 or less, it is possible to realize an electronic device having a small inter-element capacitance or inter-electrode capacitance and high reliability.

[0019]

Further, the invention of claim 3, have a greater characteristic than the ratio of 3-digit and photoconductivity and dark conductivity at room temperature
The conductivity of the region that acts as a field emitter.
Acts as a cold cathode field emitter controllable using
It is characterized in that it is used as a material for the black region, and the optical band gap is changed to 1.5 by changing the composition ratio of carbon and nitrogen.
By varying in the range of eV to 3.0 eV, it is possible to have transparency from visible light to near infrared,
Moreover, it has high hardness and high thermal conductivity, stability, moisture resistance,
It has excellent chemical resistance and abrasion resistance, and since the ratio of photoconductivity to dark conductivity is large and the dark conductivity is small, the conductivity can be easily controlled using light, and the region that functions as a field emitter can be controlled. It becomes possible to realize a freely controllable field emitter using light.

According to a fourth aspect of the invention, in the energy band structure, there is a region composed of carbon atoms and nitrogen atoms in which the localized density of states based on the π bond is small and the spread state density due to the σ bond is dominant. a manufacturing method of an amorphous carbon nitride composition, sputtering on one surface of the substrate
Sedimentary of the A Amorphous carbon nitride composition by Taringu method
The first step of applying and the amorph deposited by the first step
The surface of the carbon nitride composition is subjected to hydrogen plasma treatment.
Graphite structure in amorphous carbon nitride composition
And a second step of etching, and can be easily manufactured in a large area at a relatively low cost . In addition, by performing hydrogen plasma treatment, sp ²
Of graphite structure with double bonds composed of hybrid orbitals
Carbon is easily etched, while sp ³ hybrid gauge
Diamond structure charcoal consisting only of single bonds consisting of roads
Since the element is difficult to etch, the localized state based on π bond
If the density is reduced and the spread of densities of state due to σ coupling is
It can be formed to have an area that is dominant.
Wear. The invention of claim 5 is the same as the invention of claim 4,
The first step and the second step are alternately repeated a plurality of times.
Since the whole composition is treated with hydrogen plasma at once,
Instead, hydrogen plasma treatment is performed every time a thin film is deposited.
By stacking the
The local density of states based on the coupling is reduced, and the
It is possible to make the sharp density of states dominate.
Wear.

The invention of claim 6 is claim 4 or claim
In the invention of claim 5, since at least nitrogen gas is used as the sputtering gas, there is no danger or adverse effect on the environment, and compared with the conventional case where a gas having toxicity is used as a source gas by a plasma CVD apparatus or the like. The safety can be enhanced and the cost of the equipment including safety measures can be reduced. Further, since nitrogen is abundant in the earth, the cost of raw materials can be reduced.

The invention of claim 7 is the invention of claims 4 to 4.
In the invention of No. 6, since carbon is used as the target material, there is no danger or adverse effect on the environment, and plasma CVD is carried out using a conventional toxic gas as a source gas.
The safety can be improved as compared with the case where it is manufactured by an apparatus or the like, and the cost of equipment including safety measures can be reduced. Also, since carbon is abundant in the earth,
The cost of raw materials can be reduced.

[0024]

By the way, the amorphous carbon nitride composition exhibits a covalent bond property, and an sp ³ hybrid orbital consisting of only σ bonds and an sp ² hybrid orbital consisting of σ bonds and π bonds or s.
There are different binding states of p-hybrid orbitals. Therefore, the amorphous carbon nitride composition has an energy band structure in which a band in a spread state based on a σ bond and a π band are formed.
Localized bands due to binding are generated. Sp ² hybrid orbital or sp in amorphous carbon nitride composition
When many hybrid orbital bonds are included, the localized state density based on π bond becomes large. In this case, the proportion of electrons and holes generated by light irradiation trapped in the localized state Therefore, it is considered that the increase of carriers in the band in a broadened state based on the σ bond that contributes to conduction is not so large, and as a result, the change in conductivity due to light irradiation is less likely to occur. Further, when the density of localized states based on π bond is large, the number of carriers trapped in the localized state is large, so that the number of carriers transferred from the localized state to the band in the expanded state is large and the dark conductivity is It is considered to be relatively high. Therefore, the inventor has carried out the present invention by paying attention to the energy band structure of the amorphous carbon nitride composition.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) FIG. 1 shows a schematic view of the energy band structure of the amorphous carbon nitride composition of the present embodiment. In FIG. 1, the vertical axis represents energy and the horizontal axis represents density of states. The amorphous carbon nitride composition of the present embodiment,
As shown in FIG. 1, a valence band state 1 in a broadened state based on the bond level of the σ bond and a conduction band state 2 in a broadened state based on the antibonding level (mobility edge Ev and mobility edge Ev Ec) exists across a mobility gap Emg. by the way,
When a large amount of a structure containing a double bond such as a graphite structure is present in the composition, a large localized state 4 ′ based on a π bond as shown by a dashed line in FIG. 1 occurs in the mobility gap Emg. In the present embodiment, the density of states of the localized state 4 based on π bond is reduced.

In short, in the present embodiment, in the band structure of the amorphous carbon nitride composition, the localized density of states based on π bond is small, and the density of states spread by σ bond is more dominant, and is composed of carbon atoms and nitrogen atoms. In this region, electrons and holes generated by light irradiation are rarely trapped in a localized state, and carrier increase in a wide band due to σ bond contributing to conduction is large. As a result, the change in conductivity due to light irradiation becomes large, and the localized state based on π bond becomes small, so that the optical gap or the mobility gap E is reduced.
As mg substantially increases, the Fermi level moves near the center of the gap, and the number of carriers trapped in the localized state also decreases.Therefore, fewer carriers move from the localized state to the broadened band. , The dark conductivity decreases. Therefore, since a region having a large change in conductivity due to light irradiation and a small dark conductivity is present in the amorphous carbon nitride composition, the ratio of the photoconductivity and the dark conductivity of the composition as a whole is conventionally. It is larger than the conventional one and good photoconductivity can be obtained, and the dark conductivity can be made smaller than the conventional one. Further, if the density of localized states in the band gap is large, the excited carriers are trapped in the localized state or act as a non-radiative center, so that no light is emitted or the luminous efficiency is deteriorated. Since the density of localized states based on the .pi. Bond is reduced, it is possible to reduce the ratio of the localized states acting as traps and non-radiative centers, and as a result, it is possible to increase the luminous efficiency.

The method for producing the amorphous carbon nitride composition will be described below. In the present embodiment, an amorphous carbon nitride composition is deposited on a substrate (for example, a silicon substrate or a glass substrate) by reactive sputtering using a high frequency magnetron sputtering apparatus equipped with an RF oscillator having a frequency of 13.56 MHz as a plasma excitation source. Let Here, the sputtering gas has a purity of 99.99.
% Pure nitrogen gas is used, and graphite having a purity of 99.999% is used as a target material for sputtering. A mixed gas of pure nitrogen gas and argon gas may be used as the sputtering gas.

Next, the surface of the amorphous carbon nitride composition is subjected to a discharge treatment (hydrogen plasma treatment) with hydrogen gas to form an amorphous carbon nitride composition having the energy band structure as shown in FIG. be able to. In this embodiment, the optical band gap is changed to 1.5 eV by changing the composition of carbon and nitrogen.
To 3.0 eV can be changed.

The characteristics of the amorphous carbon nitride composition produced by the above production method will be described below. As the sputtering conditions, the gas pressure (vacuum degree) at the time of sputtering is 16 Pa, and the discharge power (sputter power) is 1
00W, substrate temperature 200 ° C, sputtering time 2
It was time. The hydrogen plasma treatment is performed by setting a shutter so that the target is not sputtered in the high frequency magnetron sputtering apparatus. The hydrogen plasma treatment is performed under the condition that the gas pressure (degree of vacuum) is 67 P.
a, the discharge power was 20 W, and the treatment time was 1.5 hours.

The DC dark conductivity of the amorphous carbon nitride composition produced under such conditions is about 1 × 10 ⁻¹⁵ S / cm at room temperature (297K), and the DC dark conductivity of amorphous silicon (1 × 10 5). ^-11 S / cm or 1 ×
A very low value was obtained as compared with 10 ^-13 S / cm).
Further, the photoconductivity when the amorphous carbon nitride composition of the present embodiment is irradiated with light having an intensity of 100 mW / cm ² using a xenon lamp is about 1 × 10 ⁻¹¹ S / cm at room temperature (297K). ^{Was 2} . Therefore, in the present embodiment, the ratio of photoconductivity and dark conductivity (photoconductivity / dark conductivity) is four digits, and the ratio of photoconductivity and dark conductivity in a conventional amorphous carbon nitride composition is It is larger than 3 digits, and it can be seen that good photoconductive characteristics are obtained.

By the way, as a comparative example, the DC dark conductivity and the photo conductivity of an amorphous carbon nitride composition not subjected to the hydrogen plasma treatment were measured under the same conditions as described above, and as a result, the DC dark conductivity was 5 × 10 ^−15. S / cm,
The photoconductivity was 5 × 10 ^-12 S / cm. That is,
It can be seen that by performing the hydrogen plasma treatment, the ratio of photoconductivity and dark conductivity is improved from 3 digits to 4 digits, and the dark conductivity is reduced to about 1/5.

The film thickness of the amorphous carbon nitride composition before the hydrogen plasma treatment was about 160 nm, but the film thickness of the amorphous carbon nitride composition after the hydrogen plasma treatment was about 100 nm, and the hydrogen plasma treatment was performed. In the applied sample, hydrogen was hardly detected by infrared spectroscopy, so that hydrogen was hardly introduced into the composition by the hydrogen plasma treatment, and the amorphous carbon nitride composition was etched by the hydrogen plasma treatment. I found out that In addition, in this etching, an incomplete structural portion such as a graphite structure in the amorphous carbon nitride composition was mainly etched, and it was confirmed by an analysis result such as infrared spectroscopy that the diamond structure worked to remain. I found it. Therefore,
In the present embodiment, by reducing the graphite structure in the amorphous carbon nitride composition by the hydrogen plasma treatment, the band of the localized state based on the π bond in the energy band structure can be made smaller, which results in the spread of the density of states due to the σ bond. It is considered that the film can be formed so as to have a region in which is more dominant, and as a result, good photoconductivity can be obtained.

The amorphous carbon nitride composition of the present embodiment has high hardness and high thermal conductivity like the conventional amorphous carbon nitride composition, and has stability, moisture resistance, chemical resistance,
It has excellent wear resistance. (Embodiment 2) The basic configuration of this embodiment is substantially the same as that of Embodiment 1, and includes a first step of depositing an amorphous carbon nitride composition by reactive sputtering, and an amorphous nitride deposited in the first step. The feature is that an amorphous carbon nitride composition having a desired thickness is formed by alternately repeating the second step of performing hydrogen plasma treatment on the surface of the carbon composition. In the first step, the first embodiment
Similarly, the gas pressure (vacuum degree) is 16 Pa and the discharge power is 10
An amorphous carbon nitride composition having a thickness of 20 nm is deposited by reactive sputtering at 0 W and a substrate temperature of 200 ° C. In the second step, the gas pressure (vacuum degree) is 67 Pa and the discharge power is the same as in the first embodiment. 20W, 10
Minute hydrogen plasma treatment is performed. In this embodiment,
The first step and the second step were alternately repeated 50 times. That is, a hydrogen plasma treatment was performed every time an amorphous carbon nitride composition having a thickness of 20 nm was deposited, and an amorphous carbon nitride composition was formed by a so-called layer-by-layer method.

FIG. 2 shows temperature characteristics of direct current dark conductivity and photoconductivity of the amorphous carbon nitride composition produced in this embodiment. The vertical axis in FIG. 2 is the conductivity, and the horizontal axis is the reciprocal of the absolute temperature T during measurement multiplied by 1000. It should be noted that a (●) in FIG. 2 indicates DC dark conductivity, and b (○), c (○), and d (○) indicate photoconductivity, and b,
The light intensities of the xenon lamps for H and D are 100 mW / cm ² , 25 mW / cm ² , and 7.5 m, respectively.
It is the measured value when W / cm ² .

From FIG. 2, in the amorphous carbon nitride composition produced in this embodiment, the DC dark conductivity at room temperature (297K) was about 1 × 10 ^-18 S / cm, which was a very small value. In addition, the light intensity of the xenon lamp is set to 10
The photoconductivity when irradiated with light at 0 mW / cm ² was about 5 × 10 ⁻¹² S / cm at room temperature (297K). In short, in the present embodiment, at room temperature, the ratio of photoconductivity to dark conductivity (photoconductivity / dark conductivity) is 5 × 10 5.
An extremely large value of ⁶ was obtained, and the dark conductivity was about 1 × 1.
A very small value of 0 ^-18 S / cm was obtained, and the first embodiment
It can be seen that the photoconductive characteristics are further improved as compared with. This is because the hydrogen plasma treatment is performed every time a relatively thin film of the amorphous carbon nitride composition is deposited by the layer-by-layer method. It is considered that this is because the number of incomplete structural parts such as a graphite structure is reduced, and the diamond structure is mainly used.

(Embodiment 3) FIG. 3 shows a sectional view of an optical sensor using amorphous carbon nitride manufactured by the same manufacturing method as in Embodiment 2. In this embodiment, a metal electrode 11 is deposited on a substrate 10 (for example, a silicon substrate on which an insulating film such as silicon oxide is formed, or an insulating substrate such as glass) is deposited, and photolithography and etching are performed. Patterning of the metal electrode 11 according to the technique, and then the reactive sputtering and the hydrogen plasma treatment are alternately performed as in the second embodiment.
An amorphous carbon nitride composition 12 having a thickness of 100 nm was formed by the layer method. Next, the amorphous carbon nitride composition 12 is patterned by the photolithography technique and the etching technique, and then the transparent electrode 13 made of indium oxide and tin oxide is deposited, and the transparent electrode 13 is formed by the photolithography technique and the etching technique. The optical sensor having the structure shown in FIG. Here, the area of the overlapping portion of the metal electrode 11 and the transparent electrode 13 is about 0.1 cm ^2.
And

When the characteristics were examined by irradiating light from the transparent electrode 13 side of the photosensor manufactured in this embodiment, the photocurrent was 0.2 μA and the dark current was 0.1 when the applied voltage was 5V.
It was 1 pA, and good light-dark characteristics that could be sufficiently used as an optical sensor were obtained. The optical gap of the amorphous carbon nitride composition 12 was about 2.2 eV. (Embodiment 4) FIG. 4 shows a schematic diagram of a main part of an optical pickup tube using an amorphous carbon nitride composition produced by the same manufacturing method as in Embodiment 2.

[0039] In the present embodiment, after depositing the transparent electrode 21 made of a <br/> oxidation in indium on the quartz glass substrate 20 and tin oxide, as well as reactive sputtering and the hydrogen plasma treatment as in Embodiment 2 An amorphous carbon nitride composition 12 having a thickness of 2 μm was formed by a layer-by-layer method in which and are alternately performed. In the present embodiment, the positive electrode of the DC power supply 23 is connected to the transparent electrode 21 via the resistor 24 so that a positive bias is applied to the transparent electrode 21. on the other hand,
The negative electrode of the DC power supply 23 is the amorphous carbon nitride composition 1
2 is connected to a cathode 25 arranged so as to face the surface 2, and an electron beam 26 emitted from the cathode 25 can scan the surface of the amorphous carbon nitride composition 12.

When the characteristics of the optical pickup tube of this embodiment were examined, the storage capacitance was about 1000 pF and the operating voltage was 10 ⁵ V /
cm, the dark current was 0.1 pA / cm ² , and sufficiently good characteristics were obtained as an optical image pickup tube. (Embodiment 5) FIG. 5 shows a sectional view of an electrophotographic photosensitive drum using an amorphous carbon nitride composition produced by the same manufacturing method as in Embodiment 2.

In this embodiment, a layer for alternately performing reactive sputtering and hydrogen plasma treatment on the drum 30 made of an aluminum substrate as in the second embodiment.
An amorphous carbon nitride composition 12 having a thickness of 100 nm was formed by the bi-layer method. In the present embodiment, the amorphous carbon nitride composition 12 constitutes a photosensitive material, and after the surface of the amorphous carbon nitride composition 12 is charged by corona discharge so that the surface potential becomes about 1000 V, the Image of amorphous carbon nitride composition 12
By irradiating the surface of, the photogenerated carriers generate a surface potential distribution according to the brightness. In the electrophotographic photosensitive drum, the insulating toner is electrostatically adsorbed according to the distribution of the surface potential, so that an image can be obtained by transferring this to the paper.

The electrophotographic photosensitive drum of this embodiment is
The dark conductivity is about 1 × 10 ⁻¹⁸ S / cm, and the dark conductivity (1 × 10 ⁻¹¹ S / cm to 1 × 10 ⁻¹³ S / cm) of the conventional electrophotographic photosensitive drum using amorphous silicon is used.
cm) and the dark conductivity of a conventional electrophotographic photosensitive drum using amorphous selenium (about 1 × 10 ⁻¹⁵ S / cm)
The thickness of the amorphous carbon nitride composition 12, which is a photoconductor, is a thin film having a thickness of about 100 nm (the thickness of the photoconductor drum for electrophotography using conventional amorphous silicon is 10 μm to 30 μm. The amount of retained charge can be reduced and the amount of retained charge can be increased accordingly, so that good photosensitivity is obtained in which image deletion does not easily occur. . Further, the amorphous carbon nitride composition of the present embodiment is harder than conventional photosensitive materials (for example, an amorphous selenium photosensitive body or an amorphous silicon photosensitive body) and is excellent in abrasion resistance, so that a surface protective film or the like is provided. It is possible to form a long-lifetime photosensitive drum without using the photosensitive drum.

(Embodiment 6) FIG. 6 shows a cross-sectional view of an example of an electrically insulating and separating structure between electrode wirings made of an amorphous carbon nitride composition manufactured by a manufacturing method similar to that of Embodiment 2. In the present embodiment, the first wiring electrode 41 made of aluminum is formed in a predetermined shape on the insulating substrate 40, and reactive sputtering and hydrogen plasma treatment are alternately performed on the first wiring electrode 41 as in the second embodiment. Amorphous carbon nitride composition 12 having a thickness of 500 nm by the layer-by-layer method
And a second layer is formed on the amorphous carbon nitride composition 12.
The wiring electrode 43 is formed in a predetermined shape, and the amorphous carbon nitride composition 12 constitutes an insulating separation film between the first wiring electrode 41 and the second wiring electrode 43. In this embodiment, the wiring width of each wiring electrode 41, 43 is 1
The relative dielectric constant of the amorphous carbon nitride composition 12 was 6 or less. In the electrical insulation / separation structure of the present embodiment, the electric capacitance between the first electrode 41 and the second electrode 43 and the leakage current were measured, and the electric capacitance was about 10 fF and the leakage current was less than 0.1 pA. And
A sufficiently small value that can be used as an interlayer insulating film of a semiconductor device or the like was obtained. That is, by using the amorphous carbon nitride composition 12 of the present embodiment as an insulating material, it becomes possible to realize an electronic device having a small inter-element capacitance and inter-electrode capacitance and high reliability, and high speed is required. there is a possibility for response to such a semiconductor device.

Reference Example FIG. 7 shows a cross-sectional view of a light emitting device using an amorphous carbon nitride composition manufactured by the same manufacturing method as in the second embodiment.
In this reference example, a transparent electrode 51 made of indium oxide and tin oxide is deposited on a transparent quartz glass substrate 50, and the transparent electrode 51 is patterned by a photolithography technique and an etching technique. Amorphous carbon nitride composition 12 having a thickness of 500 nm was formed by a layer-by-layer method in which reactive sputtering and hydrogen plasma treatment were alternately performed as in the case of form 2. Next, the amorphous carbon nitride composition 12 is patterned by the photolithography technique and the etching technique, and then the back electrode 53 made of aluminum.
Was deposited and the back electrode 53 was patterned by the photolithography technique and the etching technique to fabricate a light emitting device having a structure shown in FIG. In this embodiment, the light emission from the amorphous carbon nitride composition 12 is emitted to the outside through the transparent electrode 51 and the quartz glass substrate 50.

When an AC voltage of 150 V (frequency of, for example, several tens Hz to several kHz) is applied between the back electrode 53 and the transparent electrode 51 of the light emitting device of this reference example, light emission having a peak near a wavelength of 700 nm is obtained. 54 was obtained. (Embodiment 7 ) FIG. 8 shows a cross-sectional view of a failed emitter array using an amorphous carbon nitride composition manufactured by the same manufacturing method as in Embodiment 2.

In this embodiment, on the silicon substrate 60,
Amorphous carbon nitride composition 12 having a thickness of 50 nm is formed by the layer-by-layer method in which reactive sputtering and hydrogen plasma treatment are alternately performed as in the second embodiment. In addition, the amorphous carbon nitride composition 12
An insulating layer 6 made of silicon oxide having a thickness of 10 μm is formed on the upper surface.
2 is formed, a gate electrode 64 made of molybdenum is formed on the insulating layer 62, and the gate electrode 64 and the insulating layer 62 are formed.
Are patterned into a predetermined shape to form a plurality of field emitter regions 63 made of the amorphous carbon nitride composition 12.

In the fail-emitter array of this embodiment, when the surface of the field emitter region 63 is irradiated with the light 65 with a voltage applied to the gate electrode 64, the light 65 is emitted.
Electron emission was observed only from the field emitter region 63 irradiated with. Therefore, by using the field emitter array of this embodiment, it is possible to realize a display device capable of drawing a display pattern according to a light irradiation pattern from the outside.

Each of the embodiments described above represents one embodiment of the present invention. The conditions for producing the amorphous carbon nitride composition 12 and the amorphous carbon nitride composition 1 are as follows.
The structure of the element using 2 and the applied device are not limited to the above. In short, the amorphous carbon nitride composition 12 of the present invention comprises a photoconductive material, an insulating material,
It can be used as a light emitting device, a cold cathode material, and the like.

[0049]

According to the inventions of claims 1 to 3, the amorphous carbon nitride composition is characterized in that the localized state density based on π bonds in the energy band structure is small and the spread state density due to σ bonds is dominant. On the surface so that there is a region composed of carbon and nitrogen atoms.
Reduced graphite structure by plasma treatment
Therefore , in the above region, electrons and holes generated by light irradiation are less likely to be trapped in the localized state, and the carrier increase in the wide band due to the σ bond that contributes to conduction becomes large. As a result, the change in conductivity due to light irradiation increases. In addition, as the localized state based on π bond becomes smaller, the optical gap and mobility gap become substantially larger, the Fermi level also moves near the center of the gap, and the number of carriers trapped in the localized state is also increased. Therefore, the number of carriers moving from the localized state to the band in the spread state is reduced, and the dark conductivity is reduced. Therefore, since the region where the change in conductivity due to light irradiation is larger than that in the conventional case and the dark conductivity is smaller than that in the conventional case exists in the amorphous carbon nitride composition, the photoconductivity and the dark conductivity also exist in the composition as a whole. There is an effect that the ratio with the ratio becomes larger than that in the conventional case, good photoconductivity is obtained, and the dark conductivity can be made smaller than that in the conventional case. In addition, when the entire composition is made of carbon and nitrogen atoms in which the localized density of states based on the π bond is reduced and the spread state density due to the σ bond is more dominant, The properties of the entire composition can be improved.

[0050] Further, the invention of claim 1, have a greater characteristic than the ratio of 3-digit and photoconductivity and dark conductivity at room temperature
However, it is used as a photoconductive material, and the optical band gap is set to 1. by changing the composition ratio of carbon and nitrogen.
By varying in the range of 5 eV to 3.0 eV,
It can have sensitivity and transparency in the visible to near-infrared region, has high hardness and high thermal conductivity, and has excellent stability, moisture resistance, chemical resistance, abrasion resistance, and photoconductivity. Since the ratio of dark conductivity is large and the dark conductivity is small, a photoconductive cell, a photodetector using the photoconductive cell, an optical amplifier, an image pickup tube or an image pickup device, a photovoltaic cell or a photovoltaic cell, etc. There is a possibility of application to various applications utilizing photoconductivity such as solar cells, illuminometers, photodetectors, photodiodes, phototransistors, image sensors, etc. In particular, when used as an electrophotographic photoreceptor, the photoreceptor has excellent wear resistance and low dark conductivity, so that a high-performance and long-life photoreceptor in which an image does not flow even if the film thickness is reduced A drum can be realized, and by extension, a high-performance and long-life copier or printer to which the photosensitive drum is applied can be realized.

The invention according to claim 2 provides at least one of the characteristics that the dark conductivity at room temperature is smaller than 1 × 10 ⁻¹³ S / cm and the characteristic that the relative dielectric constant is 6 or less.
And has a characteristic that the dark conductivity at room temperature is smaller than 1 × 10 ⁻¹³ S / cm and a characteristic that the relative dielectric constant is 6 or less. By changing the composition ratio of carbon and nitrogen to change the optical bandgap in the range of 1.5 eV to 3.0 eV, it is possible to provide transparency from the visible light to the near infrared region. In addition, it has high hardness and high thermal conductivity, stability, moisture resistance,
In addition to excellent chemical resistance and abrasion resistance, it is possible to obtain an extremely small dark conductivity and a relative permittivity value of 6 or less, so the inter-element capacitance and inter-electrode capacitance are small and reliable. It becomes possible to realize an electronic device with high flexibility.

[0052]

[0053] The invention of claim 3, have a greater characteristic than the ratio of 3-digit and photoconductivity and dark conductivity at room temperature
The conductivity of the region that acts as a field emitter.
Acts as a cold cathode field emitter controllable using
It is characterized in that it is used as a material for the black region, and the optical band gap is changed to 1.5 by changing the composition ratio of carbon and nitrogen.
By varying in the range of eV to 3.0 eV, it is possible to have transparency from visible light to near infrared,
Moreover, it has high hardness and high thermal conductivity, stability, moisture resistance,
It has excellent chemical resistance and abrasion resistance, and since the ratio of photoconductivity to dark conductivity is large and the dark conductivity is small, the conductivity can be easily controlled using light, and the region that functions as a field emitter can be controlled. It becomes possible to realize a freely controllable field emitter using light.

According to a fourth aspect of the present invention, in the energy band structure, there is a region composed of carbon atoms and nitrogen atoms in which the localized density of states based on π bond is small and the spread state density due to σ bond is dominant. a manufacturing method of an amorphous carbon nitride composition, sputtering on one surface of the substrate
Sedimentary of the A Amorphous carbon nitride composition by Taringu method
The first step of applying and the amorph deposited by the first step
The surface of the carbon nitride composition is subjected to hydrogen plasma treatment.
Graphite structure in amorphous carbon nitride composition
Since the and a second step of etching, there is an effect that can be produced easily large area relatively inexpensive. In addition, by performing hydrogen plasma treatment, sp
Graphite structure with double bonds consisting of ^two hybrid orbitals
Carbon is easily etched, while sp ³ hybridized
Of a diamond structure consisting of only single bonds consisting of orbitals
Since carbon is difficult to etch, localized states based on π bonds
One with a smaller density of states and a broader density of states due to σ coupling
Can be formed to have an area in which
The effect is that you can do it. The invention of claim 5 relates to claim 4
In the invention described above, the first step and the second step are performed.
Alternately multiple times, so the entire composition can be
Rather than watering the water, each time a thin film is deposited
By applying elementary plasma treatment and stacking, the thickness direction
The local density of states based on π coupling is reduced over
However, the expanded density of states due to σ coupling is more dominant
There is an effect that can be done.

The invention of claim 6 is claim 4 or claim
In the invention of claim 5, since at least nitrogen gas is used as the sputtering gas, there is no danger or adverse effect on the environment, and compared with the conventional case where a gas having toxicity is used as a source gas by a plasma CVD apparatus or the like. There is an effect that the safety can be enhanced and the cost of the equipment including safety measures can be reduced. Further, since nitrogen is abundant in the earth, the cost of raw materials can be reduced.

The invention of claim 7 is the invention of claims 4 to 4.
In the invention of No. 6, since carbon is used as the target material, there is no danger or adverse effect on the environment, and plasma CVD is carried out using a conventional toxic gas as a source gas.
As compared with the case where the device is manufactured by the device, the safety can be improved, and the cost of the facility including the safety measures can be reduced. Further, since carbon is abundant in the earth, the cost of raw materials can be reduced.

[0057]

[Brief description of drawings]

FIG. 1 is a schematic diagram of an energy band structure showing a first embodiment.

FIG. 2 is a graph showing temperature dependence of electric conductivity of the second embodiment.

FIG. 3 is a sectional view of an optical sensor according to a third embodiment.

FIG. 4 is a configuration diagram of a main part of an optical image pickup tube according to a fourth embodiment.

FIG. 5 is a sectional view of an electrophotographic photosensitive drum according to a fifth embodiment.

FIG. 6 is a sectional view of an electrically insulating and separating structure between electrode wirings according to a sixth embodiment.

FIG. 7 is a cross-sectional view of a light emitting device of a reference example .

FIG. 8 is a sectional view of a field emitter array according to a seventh embodiment.

[Explanation of symbols]

1 valence band state 2 Conductor state 4 Localized state Emg Mobility gap

─────────────────────────────────────────────────── Continued from the front page (56) References JP-A-9-255314 (JP, A) JP-A-9-227298 (JP, A) JP-A-10-18040 (JP, A) US Patent 5110679 (US , A) International publication 96/035640 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21 / 203,21 / 363,31 / 0248 C30B 23 / 00-23 / 08 C01B 21/082

Claims (7)

(57) [Claims] 1. An amorphous carbon nitride composition, which is composed of carbon atoms and nitrogen atoms whose energy band structure has a small localized density of states based on π bonds and is predominant on a broadened density of states due to σ bonds. Area exists
Is treated by hydrogen plasma treatment on the surface like
Due to the reduction of the photo structure, the ratio of the photoconductivity at room temperature to the dark conductivity is greater than three digits , and
An amorphous carbon nitride composition characterized by being used as a material . 2. An amorphous carbon nitride composition which is composed of carbon atoms and nitrogen atoms whose energy band structure has a small localized density of states based on π bonds and is predominant on a broadened density of states due to σ bonds. Area exists
Is treated by hydrogen plasma treatment on the surface like
Due to the reduction in the structure, the dark conductivity at room temperature has at least one of the characteristics of being smaller than 1 × 10 ⁻¹³ S / cm and the characteristic of having a relative dielectric constant of 6 or less.
An amorphous carbon nitride composition characterized by being used as an edge material . 3. An amorphous carbon nitride composition, which is composed of carbon atoms and nitrogen atoms whose energy band structure has a small localized density of states based on π bonds and is more dominated by a spread state density due to σ bonds. Area exists
Is treated by hydrogen plasma treatment on the surface like
Due to the reduction of the structure, the ratio of photoconductivity to dark conductivity at room temperature is greater than 3 digits , and
Control of the conductivity of the region acting as a field emitter using light
Material in the region acting as a possible cold cathode field emitter
An amorphous carbon nitride composition, which is used as a material. 4. An amorphous carbon nitride composition having a region composed of carbon atoms and nitrogen atoms in which the localized density of states based on π bonds is small in the energy band structure and the spread of densities of states due to σ bonds is more predominant. A method of manufacturing an object, comprising a first step of depositing an amorphous carbon nitride composition on one surface side of a substrate by a sputtering method, and a hydrogen plasma treatment on the surface of the amorphous carbon nitride composition deposited by the first step. And a second step of etching the graphite structure in the amorphous carbon nitride composition by applying the amorphous carbon nitride composition. 5. The method for producing an amorphous carbon nitride composition according to claim 4, wherein the first step and the second step are alternately repeated a plurality of times. 6. The method for producing an amorphous carbon nitride composition according to claim 4 or 5, wherein at least nitrogen gas is used as a sputtering gas in the sputtering method. 7. The method for producing an amorphous carbon nitride composition according to claim 4, wherein carbon is used as a target material in the sputtering method.