JP2006045642A - Hydrogen desorption method and hydrogen desorption device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen desorption method and a hydrogen desorption device capable of controlling the characteristic of a diamond thin film, a diamond-like carbon thin film, a carbon thin film, a resin thin film or a group III-V semi-conductor thin film. <P>SOLUTION: In the hydrogen desorption method, hydrogen is desorbed from a film by irradiating a diamond thin film, a diamond-like carbon thin film, a carbon thin film, a resin thin film or a group III-V semi-conductor thin film with light rays containing photons having the energy of >10eV, and also the hydrogen is desorbed from the film by irradiating the diamond thin film, the diamond-like carbon thin film, the carbon thin film, the resin thin film or the group III-V semi-conductor thin film with light rays containing photons having the energy of >3eV and <10eV in a state that the temperature of the film is <200°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydrogen desorption method and a hydrogen desorption apparatus, and in particular, a hydrogen desorption method and hydrogen capable of controlling characteristics of a diamond thin film, a diamond-like carbon film, a carbon thin film, a resin film, or a group III-V semiconductor thin film. The present invention relates to a desorption device.

Conventionally, when forming a film such as a diamond thin film, diamond like carbon (DLC) film, carbon thin film or III-V semiconductor thin film, hydrogen is contained as a source gas or carrier gas. Gas has been used. However, when such a hydrogen-containing gas is used, hydrogen is contained in the film, and the hydrogen contained in the film affects the characteristics of the film. Even when the source gas does not contain hydrogen, H ₂ O in the residual gas may be decomposed and a trace amount of hydrogen may be mixed into the film. Therefore, it is desired to control the characteristics of the film by desorbing hydrogen from the film formed by such vapor phase synthesis. In addition, regarding the resin film, it is desired to modify the physical properties of the resin film by controlling the amount of hydrogen in the film.
JP-A-6-48716 JP-A-6-48892 JP-A-6-321690 JP-A-11-214321 JP 2000-306854 A JP-A-9-266218

  An object of the present invention is to provide a hydrogen desorption method and a hydrogen desorption apparatus capable of controlling the characteristics of a diamond thin film, a diamond-like carbon film, a carbon thin film, a resin film, or a group III-V semiconductor thin film.

  The present invention removes hydrogen from a film by irradiating a diamond thin film, a diamond-like carbon film, a carbon thin film, a resin film, or a group III-V semiconductor thin film with light containing photons having an energy of at least 10 eV. This is a hydrogen desorption method.

  Here, in the hydrogen desorption method of the present invention, it is preferable that the light applied to the film is synchrotron radiation.

  In the hydrogen desorption method of the present invention, the film temperature during light irradiation is preferably less than 200 ° C.

  The present invention also provides light containing a photon having an energy of at least greater than 3 eV and less than 10 eV on a diamond thin film, diamond-like carbon film, carbon thin film or resin film at a film temperature of less than 200 ° C. This is a hydrogen desorption method in which hydrogen is desorbed from the film by irradiation.

  The present invention also provides a film by continuously irradiating a group III-V semiconductor thin film with light containing photons having energy of at least greater than 3 eV and less than 10 eV in a state where the temperature of the film is less than 200 ° C. This is a hydrogen desorption method in which hydrogen is desorbed from the inside.

  The present invention is also a hydrogen desorption method in which light used in the above hydrogen desorption method is irradiated while forming a film on a substrate by vapor phase synthesis.

  The present invention also includes a step of forming a film with a predetermined thickness on a substrate by vapor phase synthesis, and a step of irradiating the film formed with a predetermined thickness with light used in the hydrogen desorption method. Is a hydrogen desorption method.

  Furthermore, the present invention is a hydrogen desorption apparatus including a mechanism for growing a film on a substrate by vapor phase synthesis and a mechanism for irradiating the film with light used in the above hydrogen desorption method.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen desorption method and hydrogen desorption apparatus which can control the characteristic of a diamond thin film, a diamond-like carbon film, a carbon thin film, a resin film, or a III-V group semiconductor thin film can be provided.

  Hereinafter, embodiments of the present invention will be described. In the drawings of the present application, the same reference numerals denote the same or corresponding parts.

  The present invention removes hydrogen from a film by irradiating a diamond thin film, a diamond-like carbon film, a carbon thin film, a resin film, or a group III-V semiconductor thin film with light containing photons having an energy of at least 10 eV. This is a hydrogen desorption method.

  By irradiating the above film with light including photons having energy greater than at least 10 eV in this way, the electrons constituting the hydrogen and / or atoms that are bonded to hydrogen are excited. The cutting of hydrogen bonds in the membrane is facilitated. In general, the energy that can be easily absorbed differs depending on the type of atom, but particularly energy that is greater than 10 eV and less than 3000 eV is efficiently absorbed by many types of atoms. The absorbed energy excites hydrogen and / or electrons in atoms bonded to hydrogen, thereby changing the electronic state. As a result, the hydrogen bond can be cleaved. Hydrogen having only one bond is considered to be easily desorbed and easily desorbed compared to other elements having a plurality of bonds. Thus, by desorbing hydrogen and controlling the amount of hydrogen in the film, the characteristics of the film can be controlled.

  In the case of hydrogen atoms, the electrons constituting the hydrogen atoms are most easily excited by irradiation with photons having energy greater than 10 eV and less than or equal to 100 eV. Considering other atoms bonded to hydrogen, in the case of a boron atom, a carbon atom or a nitrogen atom, photons having an energy of 500 eV or less are irradiated to cause K-shell electrons and L-shell electrons. Can be excited. In the case of an aluminum atom, a silicon atom, or a nitrogen atom, K-shell electrons and L-shell electrons can be excited by irradiation with photons having energy of 500 eV or less. It is necessary to irradiate photons having an energy of ˜3000 eV. In the case of a gallium atom, germanium atom, or arsenic atom, M-shell electrons and N-shell electrons can be excited by irradiation with photons having energy of 500 eV or less. Photons having an energy of ˜2000 eV need to be irradiated, and photons having an energy of 10 keV or more need to be irradiated for excitation of K-shell electrons. Further, in the case of an indium atom, a tin atom or an antimony atom, M-shell electrons, N-shell electrons and O-shell electrons can be excited by irradiation with photons having energy of 1000 eV or less. Is required to be irradiated with photons having energy of 3000 eV to 5000 eV, and excitation of K-shell electrons requires irradiation with photons having energy of 2 keV or more.

  Since it is considered that electrons in the film are involved in the bonding in the film, the photon having an energy of 2000 eV or less, preferably 500 eV or less, more preferably 100 eV or less is irradiated. It is considered effective for cutting hands.

  In the present invention, for example, synchrotron radiation, X-rays or free electron laser light is used as light including photons having energy greater than at least 10 eV. Among them, synchrotron radiation is used. It is preferable to be used. Since synchrotron radiation has photons having high energy in a wide energy range, it is considered effective for breaking bonds between hydrogen and many kinds of atoms. Synchrotron radiation generally includes photons having an energy of 50 eV to several keV. Therefore, when a hydrogen atom, a boron atom, a carbon atom, a nitrogen atom, an aluminum atom, a silicon atom, or a phosphorus atom is irradiated with synchrotron radiation, K-shell electrons can be excited. When gallium, germanium, arsenic, indium, tin or antimony atoms are irradiated with synchrotron radiation, excitation of K-shell electrons or L-shell electrons is difficult. Excitation is possible.

  Moreover, it is preferable that the temperature of the film at the time of irradiation with light is less than 200 ° C. Here, the temperature of the film is approximately the same as the temperature of the substrate when the film is formed on the substrate, and thus is calculated by measuring the temperature of the substrate. When the temperature of the film is less than 200 ° C., unnecessary atom diffusion in the film can be effectively prevented, so that variations in film characteristics due to factors other than the amount of hydrogen tend to be reduced. In particular, it is possible to desorb hydrogen by effectively preventing unnecessary diffusion of atoms even after a plurality of films are stacked or patterned. Further, when a resin or the like is used for the substrate or the film itself, the resin tends to be able to suppress deterioration and deterioration. In order to reduce such unnecessary diffusion of atoms and to suppress deterioration and alteration of the resin, it is more preferable that the temperature of the film is less than 100 ° C.

  The present invention also provides light containing a photon having an energy of at least greater than 3 eV and less than 10 eV on a diamond thin film, diamond-like carbon film, carbon thin film or resin film at a film temperature of less than 200 ° C. This is a hydrogen desorption method in which hydrogen is desorbed from the film by irradiation. Light including photons having an energy larger than 3 eV and smaller than 10 eV can be easily obtained at a relatively low cost by an ultraviolet lamp, an excimer laser, or the like. The regulation of the temperature of the film here is the same as described above. Of course, even when the temperature of the film is 200 ° C. or higher, the effect of modifying the film can be obtained. However, an energy range larger than 3 eV and smaller than 10 ev can provide a light source having a high photon density. Even if there is no thermal assistance at a low temperature, high-speed reforming is possible and a product with good quality is obtained. Examples of light including photons having energy of at least 3 eV and less than 10 eV include, for example, ultraviolet laser light such as excimer laser light, ultrahigh pressure mercury lamp light, high pressure mercury lamp light, low pressure mercury lamp light, or metal halide lamp. Ultraviolet lamp light such as light is used.

  The present invention also provides a film by continuously irradiating a group III-V semiconductor thin film with light containing photons having energy of at least greater than 3 eV and less than 10 eV in a state where the temperature of the film is less than 200 ° C. This is a hydrogen desorption method in which hydrogen is desorbed from the inside. The regulation of the temperature of the film here is the same as described above. Examples of the light that is continuously irradiated with photons having an energy of at least 3 eV and less than 10 eV include ultraviolet lamp light such as ultra-high pressure mercury lamp light, high pressure mercury lamp light, low pressure mercury lamp light, or metal halide lamp light. Is used.

  By irradiating light containing photons having energy of at least greater than 3 eV and less than 10 eV in such a state that the temperature of the film is less than 200 ° C., hydrogen from the film is prevented while preventing diffusion of atoms in the film. Can be desorbed. In addition, a reduction in the manufacturing cost of the film can be expected by irradiation with photons having such low energy. Further, even after a plurality of films are stacked or patterned, it is possible to effectively prevent unnecessary diffusion of atoms and desorb hydrogen. Further, when a resin or the like is used for the substrate or the film itself, it tends to be possible to suppress the deterioration and alteration of the resin. In order to reduce such unnecessary diffusion of atoms and to suppress deterioration and alteration of the resin, it is more preferable that the temperature of the film is less than 100 ° C. In addition, it is considered that the desorption of hydrogen by irradiation with photons having such a low energy can be performed not only by bond breakage due to electron excitation but also by other mechanisms.

  In the case of a diamond thin film, diamond-like carbon film, carbon thin film, or resin film, the desorption of hydrogen is effective in either continuous light irradiation or intermittent light irradiation such as pulsed laser light. To be done. However, in the case of a III-V group semiconductor thin film, it seems that hydrogen is more reliably desorbed by continuous light irradiation. Although the reason is unknown, it is considered that it is better to continuously irradiate light because hydrogen in the group III-V semiconductor thin film is easily recombined even if the bond is broken once.

  In the control of film characteristics by heat treatment that is generally performed, there is a problem that the diamond-like carbon film, carbon thin film, or resin film disappears or graphitizes, and the diamond thin film also has a problem of graphitization. Further, the III-V semiconductor thin film has a problem of atomic diffusion and composition change. Therefore, these problems can be solved by applying characteristic control by irradiation of light to these films.

  Here, in the present invention, the diamond thin film refers to a film that is formed by vapor phase synthesis, is crystalline, and shows a diffraction line reflecting a diamond structure in X-ray diffraction. Further, in the present invention, the diamond-like carbon film is an amorphous film formed by vapor phase synthesis and mainly composed of carbon or carbon and hydrogen and having a Knoop hardness of 1000 or more. Say. In the present invention, the carbon thin film is an amorphous film formed by vapor phase synthesis and mainly composed of carbon or carbon and hydrogen, and has a Knoop hardness of 30 or more and less than 1000. Say. The resin film is a general hydrocarbon resin film containing carbon and hydrogen as main components or a silicone resin film containing silicon and hydrogen as main components. Chlorine, nitrogen, oxygen or sulfur. The III-V group semiconductor thin film refers to a film made of a semiconductor crystal such as GaAs, GaN, GaInN, or GaInAlN formed by vapor phase synthesis.

  Further, examples of the vapor phase synthesis method used in the present invention include a high-frequency plasma CVD method or a MOCVD method (metal organic chemical vapor deposition method). Examples of the substrate used in the present invention include a glass substrate, a quartz substrate, a resin substrate, a ceramic substrate, and a semiconductor substrate.

  In the present invention, it is possible to irradiate light containing photons having energy as described above while forming a film on the substrate by vapor phase synthesis. A schematic configuration diagram of FIG. 1 shows a preferable example of a hydrogen desorption apparatus capable of performing such light irradiation. In FIG. 1, a substrate 3 placed on a substrate electrode 2 is held in a film forming chamber 1 into which a source gas is introduced. Then, a high frequency is applied to the substrate electrode 2 while continuously irradiating the ultraviolet ray lamp light 19 from the ultraviolet lamp 5 into the film formation chamber 1 through the window 4 installed in the upper part of the film formation chamber 1, thereby the substrate 3. A film is formed on top.

  Thus, by irradiating with ultraviolet light while forming a film on a substrate by vapor phase synthesis, hydrogen tends to be sufficiently desorbed in the film thickness direction. That is, in general, hydrogen can be sufficiently desorbed from the light irradiation surface toward the film thickness direction by light attenuation or recombination of hydrogen once desorbed in the film thickness. There is a tendency not to. However, irradiation with light while forming a film as described above makes it possible to sufficiently desorb hydrogen in the film thickness direction.

  In the present invention, the step of forming a film with a predetermined thickness on the substrate by vapor phase synthesis and the step of irradiating the above-described light onto the film formed with a predetermined thickness can be repeated. Also in this case, hydrogen tends to be sufficiently desorbed in the film thickness direction.

  A schematic configuration diagram of FIG. 2 shows a preferable example of a hydrogen desorption apparatus capable of performing such light irradiation. In FIG. 2, the substrate 9 placed on the substrate holder 10 is held in the film forming chamber 12 into which the source gas has been introduced. Then, by applying a high frequency to the substrate holder 10, a film 13 having a predetermined thickness is formed on the substrate 9. Next, after opening the bulb 11, the substrate holder 10 is transferred into the irradiation chamber 8. Then, the bulb 11 is closed, the bulb 7 is opened, and the film 13 in the irradiation chamber 8 is irradiated with the synchrotron radiation light 6 from the light source. Here, when the synchrotron radiation 6 is irradiated, the synchrotron radiation 6 can be irradiated on the entire surface of the film 13 by appropriately moving the substrate holder 10.

  Then, after the valve 7 is closed and the irradiation of the synchrotron radiation 6 is finished, the valve 11 is opened, and the substrate holder 10 is transferred to the film forming chamber 12 again. A film having a predetermined thickness is further formed on the film 13 after the irradiation with the synchrotron radiation 6. Thereafter, the substrate holder 10 is again conveyed to the irradiation chamber 8 and the synchrotron radiation light 6 is irradiated to the newly formed film. Thus, every time a film having a predetermined film thickness is formed, the desorption of hydrogen in the film thickness direction tends to be sufficiently performed by irradiating synchrotron radiation. Here, the “predetermined film thickness” is not particularly limited as long as hydrogen can be sufficiently desorbed in the film thickness direction by light irradiation.

  Further, in the present invention, only a part of the film can be irradiated with light containing photons having the energy as described above. For example, in the schematic cross-sectional view of FIG. 3, a gold mask 15 patterned in a plurality of lines is formed on the surface of a diamond-like carbon film or carbon thin film 14. The line-shaped gold mask 15 has a rectangular shape in a cross section orthogonal to the length direction, and has a considerable thickness. From above the gold mask 15, the synchrotron radiation 16 includes photons having energy as described above obliquely on the surface of a diamond-like carbon film or carbon thin film 14 formed on a substrate (not shown). Is irradiated. The portion irradiated with the synchrotron radiation light 16 is desorbed with hydrogen to become a region 17 having a relatively high refractive index, and the portion not irradiated with the synchrotron radiation light 16 has a relatively low refractive index. Region 18 is formed. In the present invention, the synchrotron radiation 16 may be irradiated in a direction perpendicular to the surface of the diamond-like carbon film or the carbon thin film 14.

  Thus, the diamond-like carbon film or carbon thin film in which the refractive index distribution is formed in the surface can be used as a refractive index modulation type diffractive optical element, for example. The present inventor has confirmed that the maximum refractive index change amount of the diamond-like carbon film or carbon thin film can be increased to about Δn = 0.50 by irradiation with synchrotron radiation. Furthermore, it has also been confirmed that the maximum refractive index change amount of the diamond-like carbon film or carbon thin film can be increased to Δn = 0.20 or more even by irradiation with ultraviolet light. The amount of change in the refractive index of such a diamond-like carbon film or carbon thin film is significantly larger than the amount of change in the refractive index (Δn = 0.01 or less) due to ultraviolet light irradiation on a conventional silica glass. I understand. It is known that the diffraction efficiency of a refractive index modulation type diffractive optical element can be increased as the refractive index difference Δn in the refractive index modulation increases.

In FIG. 4, the wavelength branching action in the case where a refractive index modulation type diffractive optical element using a diamond-like carbon film or carbon thin film having a refractive index distribution in the surface is used as a wavelength coupler is schematically shown. Illustrated in cross-sectional view. As shown in FIG. 4, for example, when a single incident light including a plurality of wavelengths λ ₁ , λ ₂ , λ ₃ , and λ ₄ is incident on the diffractive optical element, the light passes through the diffractive optical element. The diffraction angles of incident light differ depending on the wavelength. As a result, a single incident light including a plurality of wavelengths can be separated into a plurality of diffracted lights having different traveling directions for each wavelength. If the directions of the incident light and the diffracted light indicated by the arrows in FIG. 4 are reversed, the diffractive optical element of FIG. 4 can be used as a multiplexer.

  FIG. 5 is a schematic cross-sectional view illustrating the power branching action when the diffractive optical element shown in FIG. 4 is used as an optical coupler (power branching device). That is, if incident light having a single wavelength having power P is incident on the diffractive optical element, the diffraction angles of the incident light passing through the diffractive optical element differ from each other depending on the diffraction order. As a result, incident light having a single wavelength can be separated into a plurality of diffracted lights each having a power of P / 4.

  FIG. 6 is a schematic cross-sectional view illustrating the polarization branching action when the diffractive optical element shown in FIG. 4 is used as a polarization beam splitter. That is, if a TEM wave including a TE component and a TM component is incident on the diffractive optical element, the TE wave and the TM wave are diffracted at different diffraction angles depending on the difference in polarization. Therefore, the TE wave and the TM wave can be branched.

  In FIG. 3, FIG. 4, FIG. 5, and FIG. 6, the description of the substrate is omitted for convenience of explanation.

  As described above, for diamond-like carbon films or carbon thin films, optical properties such as refractive index and extinction coefficient can be controlled by controlling the amount of hydrogen in these films. It can be used not only as an optical element but also as an optical waveguide or a recording medium. Moreover, hardness and wear resistance can be improved by reducing the amount of hydrogen in the film.

  In addition, for a diamond thin film formed by vapor phase synthesis, the insulation, activation rate, thermal conductivity, etc. can be improved by reducing the amount of hydrogen in the diamond thin film. That is, with respect to insulation, it is possible to suppress a reduction in electrical resistance due to hydrogen in the diamond thin film. In addition, as for the activation rate, dopants such as boron may not be successfully replaced by carbon constituting the diamond lattice due to hydrogen in the diamond thin film, and by removing hydrogen, the rate of dopant substitution is improved and activated. The rate can be improved. Regarding thermal conductivity, by reducing the amount of hydrogen in the diamond thin film, the phonon scattering factor can be reduced and the thermal conductivity can be improved.

  Furthermore, as for the III-V group semiconductor thin film, the hydrogen contained in the group III-V semiconductor thin film may be combined with elements or dopants constituting the crystal to prevent activation, so that the group III-V semiconductor thin film Activation can be promoted by reducing the amount of hydrogen therein. Further, with respect to the resin film, by reducing the amount of hydrogen in the resin film, it can contribute to prevention of charging of the resin film, improvement of light shielding property, or improvement of wear resistance.

(Experimental example 1)
A diamond thin film formed on a substrate by vapor phase synthesis was irradiated with 80 mA · min / mm ^{2 of} synchrotron radiation composed of photons having an energy of 50 eV to 2000 eV. Here, the temperature of the diamond thin film when irradiated with synchrotron radiation was 180 ° C. The amount of hydrogen after irradiation with synchrotron radiation in the diamond thin film was reduced to 1/5 before irradiation, and the thermal conductivity increased 1.7 times before irradiation. The amount of hydrogen was calculated from the amount of absorption caused by the hydrogen-containing group by FTIR (Fourier transform infrared spectrophotometer), and the thermal conductivity was measured by the laser heating AC method.

(Experimental example 2)
An X-ray CuKα ray (photon energy amount of 8052 eV) is applied to a carbon thin film having 55 atomic% and a refractive index of 1.55 formed on the SiO ₂ substrate by vapor phase synthesis at an output of 5 kW and 30 Irradiated for 1 minute. Here, the substrate temperature at the time of irradiation with CuKα rays was controlled to 100 ° C. or less by water cooling. The amount of hydrogen in the carbon thin film after irradiation with CuKα rays decreased to 37 atomic%, and the refractive index increased to 1.74. Here, the amount of hydrogen was calculated by RBS (Rutherford Back Scattering) / ERDA (Elastic Recoil Detection Analysis) method, and the refractive index was calculated by spectroscopic ellipso.

  On the other hand, when the substrate was not cooled at the time of irradiation with CuKα rays, the substrate temperature at the time of irradiation with CuKα rays increased from 250 ° C. to 300 ° C. As described above, the hydrogen content of the carbon thin film irradiated with CuKα rays without cooling the substrate decreased to 35 atomic% and the refractive index increased to 1.75, but the extinction coefficient was as described above with water cooling. As a result, the substrate was cooled to 2.3 times that when CuKα rays were irradiated. Here, the amount of hydrogen was calculated by the RBS / ERDA method, and the refractive index and extinction coefficient were calculated by a spectroscopic ellipso.

(Experimental example 3)
Boron ions were implanted at 5 × 10 ¹⁵ ions / cm ² into the diamond thin film formed on the substrate by vapor phase synthesis. Then, KrF laser light having a wavelength of 248 nm (photon energy amount 5.0 eV) was irradiated at an average output of 80 W / cm ² in a state where the surface of the diamond thin film after boron ions were implanted was at a temperature of 150 ° C. or lower.

On the other hand, a diamond thin film in which boron ions formed in the same manner as described above were implanted at 5 × 10 ¹⁵ ions / cm ² was annealed in vacuum at 500 ° C. for 3 hours instead of irradiating with KrF laser light. .

  When comparing the diamond thin film after the above treatment, the diamond thin film irradiated with the KrF laser beam has an electrical resistance of 1/10 or less and a hydrogen content of 1 compared with the annealed diamond thin film. / 4 was confirmed. Here, the electrical resistance was measured by the four-terminal method and the two-terminal method, respectively, and the amount of hydrogen was calculated by FTIR.

(Experimental example 4)
A 300 W ultraviolet lamp including a photon having a wavelength of 185 nm (photon energy amount 6.7 eV) and a photon having a wavelength of 254 nm (photon energy amount 4.88 eV) was installed in the high-frequency plasma CVD apparatus. Then, methane was introduced into the high-frequency plasma CVD apparatus as a raw material, and a diamond-like carbon film was grown while irradiating with ultraviolet light using the above-described ultraviolet lamp. Here, the temperature in the high-frequency plasma CVD apparatus during the growth of the diamond-like carbon film was 180 ° C.

  On the other hand, a diamond-like carbon film was grown under the same conditions as above except that no ultraviolet lamp was used.

  When comparing the diamond-like carbon film after the above treatment, the amount of hydrogen in the diamond-like carbon film grown without using an ultraviolet lamp was 38 atomic%, and the Knoop hardness was 1600. In contrast, the amount of hydrogen in the diamond-like carbon film grown while irradiating with ultraviolet light using an ultraviolet lamp was 28 atomic%, and the Knoop hardness was 2100. Here, the amount of hydrogen was calculated by the RBS / ERDA method, and the Knoop hardness was calculated by measuring with a Knoop hardness meter at a load of 25 g.

(Experimental example 5)
Made of p-type Ga _0.9 Al _0.1 N doped with Mg, using TMG (trimethylgallium), TMA (trimethylaluminum), NH ₃ (ammonia) and Cp ₂ Mg (cyclopentadienylmagnesium) as raw materials by MOCVD. The film was grown to a thickness of 3 μm. The film was irradiated with synchrotron radiation composed of photons of 50 eV to 2000 eV (average 800 eV) in a nitrogen atmosphere at 25 mA · min / mm ² . Here, the temperature of the film made of the p-type Ga _0.9 Al _0.1 N at the time of irradiation with synchrotron radiation was 150 ° C.

When a hole measurement was performed on a film made of p-type Ga _0.9 Al _0.1 N after irradiation with synchrotron radiation with a hole measuring device, the electrical resistivity was 0.8 Ω · cm and the hole carrier concentration was 5 × 10 5. It was ¹⁸ cm ⁻³ and was confirmed to exhibit excellent p-type characteristics.

Further, a photon having a wavelength of 185 nm (photon energy amount 6.7 eV) and a wavelength of 254 nm (photon energy amount 4) are applied to a film made of p-type Ga _0.9 Al _0.1 N grown by MOCVD in the same manner as described above. It was irradiated for 120 minutes at an intensity of 200 mW / cm ² low-pressure mercury lamp light including the photons .88eV). Here, the temperature of the film made of the p-type Ga _0.9 Al _0.1 N at the time of irradiation with the low-pressure mercury lamp light was set to 150 ° C. When a hole measurement was performed on the film made of p-type Ga _0.9 Al _0.1 N after irradiation with low-pressure mercury lamp light in the same manner as described above, the electrical resistivity was 1.0 Ω · cm and the hole carrier concentration was 8 × 10 8. It was ¹⁸ cm ⁻³ and was confirmed to exhibit excellent p-type characteristics.

Further, a pulse irradiation excimer laser beam containing photons having a wavelength of 248 nm (photon energy amount 5.0 eV) is applied to a film made of p-type Ga _0.9 Al _0.1 N grown by MOCVD in the same manner as described above. Was irradiated for several conditions at an intensity of 200 mW / cm ² for 30 to 150 minutes. Here, the temperature of the film made of p-type Ga _0.9 Al _0.1 N at the time of excimer laser light irradiation was set to 150 ° C. When holes were measured in the same manner as described above for a film made of p-type Ga _0.9 Al _0.1 N after irradiation with excimer laser light, the electrical resistivity and hole carrier concentration varied. This is thought to be due to the existence of factors that cannot be controlled due to problems specific to pulse irradiation, but the details of the cause of the above-mentioned variation are unknown. From the viewpoint of stabilizing the properties of the p-type Ga _0.9 Al _0.1 N film after the modification, it is considered preferable to use continuous irradiation type light such as ultraviolet lamp light.

(Experimental example 6)
A resin film made of a polyethylene film having a thickness of 300 μm was irradiated with synchrotron radiation made of photons having energy of 50 eV to 2000 eV at 30 mA · min / mm ² . Here, the temperature of the resin film when irradiated with synchrotron radiation was 100 ° C. After irradiation with synchrotron radiation, the amount of hydrogen on the outermost surface of the resin film made of polyethylene film was calculated by the RBS / ERDA method. The amount of hydrogen on the outermost surface before irradiation with synchrotron radiation was reduced by about 22%. Was. As the amount of hydrogen decreased, conductivity was imparted to the surface of the resin film, which was effective in preventing charging of the resin film made of a polyethylene film. The conductivity was confirmed by the four-terminal method.

(Experimental example 7)
A resin film made of acrylic resin was applied on a glass substrate with a thickness of 1 μm. The resin film was irradiated with synchrotron radiation composed of photons having energy of 50 eV to 2000 eV at 20 mA · min / mm ² . Here, the temperature of the resin film during irradiation with synchrotron radiation was maintained at 100 ° C. or lower. After irradiation with synchrotron radiation, the amount of hydrogen on the outermost surface of the resin film made of acrylic resin was calculated by the RBS / ERDA method. As a result, the amount of hydrogen on the outermost surface before irradiation with synchrotron radiation was reduced by about 18%. Was. As the amount of hydrogen decreased, the surface of the resin film became light brown and the light shielding property was improved.

(Experimental example 8)
A resin film made of silicone resin was applied on a stainless steel substrate to a thickness of 10 μm. The resin film was irradiated with ultraviolet lamp light containing photons having a wavelength of 300 nm (photon energy amount: 4.13 eV) or less at 200 W / cm ² for 10 hours. Here, the temperature of the resin film during the irradiation with the ultraviolet lamp light was maintained at 100 ° C. or lower. When the amount of hydrogen on the outermost surface of the resin film made of silicone resin was calculated by RBS / ERDA after irradiation with ultraviolet lamp light, the amount was about 22% less than the amount of hydrogen on the outermost surface before irradiation with ultraviolet lamp light. . The resin film made of silicone resin after irradiation with ultraviolet lamp light had a wear resistance of 15 times or more compared with that before irradiation with ultraviolet lamp light. The abrasion resistance was evaluated by a dry pin-on-disk method. Here, the counterpart material in the dry pin-on-disk method was SUS304, the load was 0.1 N, and the sliding speed was 100 mm / s.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, the characteristics of a film can be controlled by desorbing hydrogen in a diamond thin film, diamond-like carbon film, carbon thin film, resin film or III-V semiconductor thin film.

It is a typical block diagram of a preferable example of the hydrogen desorption apparatus in this invention. It is a typical block diagram of the other preferable example of the hydrogen desorption apparatus in this invention. It is typical sectional drawing illustrating the case where light is irradiated to only a part of film | membrane in this invention. FIG. 5 is a schematic cross-sectional view illustrating the wavelength branching action when a refractive index modulation type diffractive optical element using a film having a refractive index distribution in the surface is used as a wavelength multiplexer / demultiplexer. FIG. 5 is a schematic cross-sectional view illustrating the power branching action when the diffractive optical element shown in FIG. 4 is used as an optical coupler (power branching device). FIG. 5 is a schematic cross-sectional view illustrating the polarization branching action in the case where the diffractive optical element shown in FIG. 4 is used as a polarization combiner.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,12 Film formation chamber, 2 Substrate electrode, 3,9 Substrate, 4 Window, 5 Ultraviolet lamp, 6,16 Synchrotron radiation, 7,11 Bulb, 8 Irradiation chamber, 10 Substrate holder, 13 Film, 14 Diamond shape Carbon film or carbon thin film, 15 gold mask, 17 region having a relatively high refractive index, 18 region having a relatively low refractive index, 19 ultraviolet lamp light.

Claims (8)

  Desorbing hydrogen from the film by irradiating the diamond thin film, diamond-like carbon film, carbon thin film, resin film or III-V semiconductor thin film with light containing photons having energy of at least greater than 10 eV. A method for desorbing hydrogen.   2. The hydrogen desorption method according to claim 1, wherein the light applied to the film is synchrotron radiation.   The hydrogen desorption method according to claim 1 or 2, wherein the temperature of the film at the time of irradiation with light is less than 200 ° C.   By irradiating a diamond thin film, a diamond-like carbon film, a carbon thin film or a resin film with light containing photons having an energy of at least greater than 3 eV and less than 10 eV in a state where the temperature of the film is less than 200 ° C. A method for desorbing hydrogen, wherein hydrogen is desorbed from the film.   By continuously irradiating the group III-V semiconductor thin film with light containing photons having energy larger than 3 eV and smaller than 10 eV in a state where the temperature of the film is lower than 200 ° C., hydrogen is radiated from the film. A method for desorbing hydrogen, comprising desorbing.   6. A hydrogen desorption method comprising irradiating light used in the hydrogen desorption method according to claim 1 while forming a film on a substrate by vapor phase synthesis.   6. A step of forming a film with a predetermined thickness on a substrate by vapor phase synthesis; and the light used in the hydrogen desorption method according to claim 1 on the film formed with a predetermined thickness. And a step of irradiating the hydrogen desorption method.   A hydrogen desorption apparatus comprising: a mechanism for growing a film on a substrate by vapor phase synthesis; and a mechanism for irradiating the film with light used in the hydrogen desorption method according to claim 1.

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