# US 8,047,653 B2 · Si-O containing hydrogenated carbon film, optical device including the same, and method for manufacturing the Si-O containing hydrogenated carbon film and the optical device

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- Number: US 8,047,653 B2
- Document ID: US8047653B2
- Status: Granted
- Kind: B2
- Application number: 12/514,238
- Filed: 2007-10-31
- Published: 2010-02-18
- Granted: 2011-11-01
- Earliest claimed: 2006-11-10
- Assignees: Sumitomo Electric Industries, Ltd.
- Inventors: Yoshihiro Akahane; Takahiro Imai; Takashi Matsuura; Tetsuya Katayama; Toshihiko Ushiro
- Web page: https://patentgrep.com/patent/US8047653B2

## CPC

- G02B 5/1857: {using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C01B 32/15: Nano-sized carbon materials
- G02B 3/0012: {characterised by the manufacturing method}
- G02B 3/0087: {with index gradient}
- G02B 27/283: {used for beam splitting or combining}
- G03H 1/02: Details {of features involved during the holographic process; Replication of holograms without interference recording}
- H04N 9/3129: {scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161)}
- H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)}
- H04N 9/3167: {for polarizing the light beam (polarizing optical systems per se G02B27/28)}
- G02B 1/105
- G02B 1/14: Protective coatings, e.g. hard coatings
- G03H 2001/0268: {Inorganic recording material, e.g. photorefractive crystal [PRC]}
- Y10S 427/106: Utilizing plasma, e.g. corona, glow discharge, cold plasma
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- G03H: HOLOGRAPHIC PROCESSES OR APPARATUS (holograms, e.g. point holograms, used as ordinary optical elements G02B5/32; producing stereoscopic or other three-dimensional effects G02B30/00; diffraction-grating systems G02B27/44; systems using moiré fringes G02B27/60; optical logic elements G02F3/00; stereo-photography G03B35/00; photosensitive materials or processes for photographic purposes G03C; {stereo-photographic or similar processes G03C9/00}; apparatus for processing exposed photographic materials G03D; analogue computers performing mathematical operations with the aid of optical elements G06E3/00; authentication by radiation, of concealed information carried by holograms or diffraction gratings G06K19/16; holographic storage G11B7/0065, G11C13/04; {stereoscopic or other three dimensional effects in television systems H04N13/00})
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

An Si—O containing hydrogenated carbon film as an optical film has a refractive index in a range from at least 1.48 to at most 1.85 for light of 520 nm wavelength and an extinction coefficient of less than 0.15 for light of 248 nm wavelength, wherein the refractive index and the extinction coefficient are decreased with energy beam irradiation. By utilizing such an Si—O containing hydrogenated carbon film, it is possible to provide various types of optical elements and an optical device including the same.

## Claims

### Claim 1

An Si—O containing hydrogenated carbon film which has a refractive index in a range from at least 1.48 to at most 1.85 for light of 520 nm wavelength and an extinction coefficient of less than 0.15 for light of 248 nm wavelength, wherein said refractive index and said extinction coefficient are decreased with energy beam irradiation.

### Claim 2 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein said extinction coefficient for the light of 248 nm wavelength is less than 0.12 before said energy beam irradiation.

### Claim 3 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein said refractive index for the light of 520 nm wavelength is in a range from at least 1.56 to at most 1.76 before said energy beam irradiation.

### Claim 4 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein said refractive index for the light of 520 nm wavelength is decreased with said energy beam irradiation by an amount of change in a range from at least 0.03 to at most 0.40, and the decreased refractive index is at least 1.45.

### Claim 5 (depends on 4)

The Si—O containing hydrogenated carbon film according to claim 4, wherein said amount of change in said refractive index is in a range from at least 0.10 to at most 0.30.

### Claim 6 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein, before said energy beam irradiation, silicon content is more than 0.80×1022 atoms/cm3 and less than 1.5×1022 atoms/cm3, hydrogen content is more than 4.0×1022 atoms/cm3 and less than 8.0×1022 atoms/cm3, oxygen content is more than 0.80×1022 atoms/cm3 and less than 1.4×1022 atoms/cm3, carbon content is more than 1.5×1022 atoms/cm3 and less than 2.3×1022 atoms/cm3, an atomic % ratio of O/Si is more than 0.5 and less than 1.5, and an atomic % ratio of C/Si is more than 1.0 and less than 3.0.

### Claim 7 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein, before said energy beam irradiation, degree of density is in a range from more than 1.15 g /cm3 to less than 1.60 g/cm3, and spin density is in a range from more than 1.0×1016 spins/cm3 to less than 1.0×1020 spins/cm3.

### Claim 8 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein, after said energy beam irradiation, silicon content is more than 0.80×1022 atoms/cm3 and less than 1.5×1022 atoms/cm3, hydrogen content is more than 1.0×1022 atoms/cm3 and less than 8.0×1022 atoms/cm3, oxygen content is more than 0.80×1022 atoms/cm3 and less than 3.0×1022 atoms/cm3, carbon content is more than 1.0×1022 atoms/cm3 and less than 2.3×1022 atoms/cm3, an atomic % ratio of O/Si is more than 0.5 and less than 2.0, and an atomic % ratio of C/Si is more than 1.0 and less than 3.0.

### Claim 9 (depends on 1)

The Si—O containing hydrogenated carbon film according to claim 1, wherein, after said energy beam irradiation, degree of density is in a range from more than 1.15 g/cm3 to less than 1.80 g/cm3, and spin density is less than 1.0×1020 spins/cm3 .

### Claim 10 (depends on 1)

A method for manufacturing the Si—O containing hydrogenated carbon film of claim 1, wherein said film is formed by plasma CVD using siloxanes as a source material, and a condition for the plasma CVD is that substrate temperature is at least 80° C. and at most 100° C., high-frequency power is at least 0.5 W/cm2 and at most 1.2 W/cm2, pressure is at least 6.7 Pa and at most 40 Pa, and the pressure until elapsed time of at least 3 minutes after a start of film formation is continuously increased at a rate in a range from at least 1.3 Pa/minute to at most 2.7 Pa/minute.

### Claim 11 (depends on 1)

An optical element fabricated with use of the Si—O containing hydrogenated carbon film of claim 1, wherein the optical element includes a local region having a relatively high refractive index and a local region having a relatively low refractive index.

### Claim 12 (depends on 11)

The optical element according to claim 11, wherein said local region having the relatively high refractive index is a region which has not undergone said energy beam irradiation in said Si—O containing hydrogenated carbon film.

### Claim 13 (depends on 11)

The optical element according to claim 11, wherein said local region having the relatively low refractive index is a region which has undergone said energy beam irradiation in said Si—O containing hydrogenated carbon film.

### Claim 14 (depends on 11)

A method for manufacturing the optical element of claim 11, wherein said local region having the relatively low refractive index is formed by said energy beam irradiation with a corpuscular beam including an ion beam, an electron beam, or a neutron beam, or an electromagnetic wave including an ultraviolet ray, an X-ray, or a gamma ray.

### Claim 15 (depends on 1)

An optical film, wherein the Si—O containing hydrogenated carbon film of claim 1 is formed on a substrate, and at least one protective layer made of any of an oxide film, a nitride film, an oxynitride film, a fluoride film, and a film containing carbon and hydrogen as a major component is superposed on the Si—O containing hydrogenated carbon film.

### Claim 16 (depends on 1)

An optical film, wherein the Si—O containing hydrogenated carbon film of claim 1 is formed on a substrate, and a transparent material plate having a thickness of at least 10 μm is joined on the Si—O containing hydrogenated carbon film.

### Claim 17 (depends on 15)

The optical film according to claim 15, wherein a transparent material plate having a thickness of at least 10 μm is joined on said protective layer.

### Claim 18 (depends on 15)

An optical element comprising the optical film of claim 15, wherein said Si-O containing hydrogenated carbon film has a refractive-index-modulated structure.

### Claim 19 (depends on 1)

A flat plate-type microlens formed with use of the Si—O containing hydrogenated carbon film of claim 1, wherein said Si—O containing hydrogenated carbon film includes a region having its refractive index modulated, and produces a lens effect when a light flux passes through said region having its refractive index modulated.

### Claim 20 (depends on 1)

An optical information record medium comprising the Si—O containing hydrogenated carbon film of claim 1 deposited on a substrate, wherein recording of information on the optical information record medium can be performed by irradiating a recording spot region selected from a plurality of recording spot regions with the energy beam, and decreasing the refractive index of said Si—O containing hydrogenated carbon film in the selected recording spot region.

### Claim 21 (depends on 1)

A polarization integrator comprising: a polarization beam splitter for separating light from a light source into P-polarized light and S-polarized light; a first microlens; a half-wavelength plate; and a second microlens, wherein
said first microlens is disposed to converge the P-polarized light and the S-polarized light separated by said polarization beam splitter to positions different from each other,
said half-wavelength plate is disposed at a position to which said P-polarized light or said S-polarized light is converged, so as to serve to convert the P-polarized light into S-polarized light or convert the S-polarized light into P-polarized light,
said second microlens serves to integrate the S-polarized light or the P-polarized light having passed through said half-wavelength plate and converted into the other polarization, with the S-polarized light or the P-polarized light having not passed through said half-wavelength plate, and
at least one of said polarization beam splitter, said first microlens, said half-wavelength plate, and said second microlens is formed by using the Si—O containing hydrogenated carbon film of claim 1.

### Claim 22 (depends on 21)

The polarization integrator according to claim 21, wherein at least one of said polarization beam splitter and said half-wavelength plate is formed of a refractive index modulated-type diffraction grating formed in said Si—O containing hydrogenated carbon film.

### Claim 23 (depends on 21)

A liquid crystal projector comprising the polarization integrator of claim 21.

### Claim 24 (depends on 1)

A projector comprising: a light source; and an diffractive optical element for diffracting light from the light source, wherein
said diffractive optical element includes the Si—O containing hydrogenated carbon film of claim 1 formed on a transparent substrate,
said Si—O containing hydrogenated carbon film is subjected to refractive index modulation so as to include a plurality of regions having a relatively high refractive index and a plurality of regions having a relatively low refractive index, for causing diffraction of the light, and
said refractive index modulation causes a diffraction effect so as to convert an intensity distribution in a cross section of a light beam directed to said Si—O containing hydrogenated carbon film into a uniform intensity distribution on a prescribed irradiation surface.

### Claim 25 (depends on 24)

The projector according to claim 24, wherein said refractive index modulation also causes a diffraction effect so as to convert a cross-sectional shape of the light beam directed to said Si—O containing hydrogenated carbon film into a prescribed cross-sectional shape on said prescribed irradiation surface.

### Claim 26 (depends on 1)

A color liquid crystal display device comprising: a light source; a holographic color filter; and a liquid crystal panel, wherein
said holographic color filter includes the Si—O containing hydrogenated carbon film of claim 1 formed on a transparent substrate,
said Si—O containing hydrogenated carbon film has a refractive-index-modulated structure in which a band-like region having a relatively high refractive index and a band-like region having a relatively low refractive index are alternately disposed, and has a function of diffracting and spectroscopically splitting, by a hologram, incident light supplied from said light source, so as to emit lights of different wavelengths at a prescribed spatial periodicity, and
said spatial periodicity corresponds to a periodicity of a plurality of pixels included in said liquid crystal panel.

### Claim 27 (depends on 26)

The color liquid crystal display device according to claim 26, wherein said band-like region having the relatively high refractive index has its width and interval being periodically changed corresponding to said spatial periodicity, so as to cause said holographic color filter to have not only a spectroscopic function but also a microlens array function.

### Claim 28 (depends on 26)

The color liquid crystal display device according to claim 26, wherein the refractive index is continuously changed in a boundary region between said band-like region having the low refractive index and said band-like region having the high refractive index in said holographic color filter.

### Claim 29 (depends on 26)

The color liquid crystal display device according to claim 26, wherein a boundary region between said band-like region having the low refractive index and said band-like region having the high refractive index in said holographic color filter is tilted with respect to a thickness direction of said Si—O containing hydrogenated carbon film.

### Claim 30 (depends on 26)

The color liquid crystal display device according to claim 26, wherein each of the plurality of pixels included in said liquid crystal panel includes a red display region, a green display region and a blue display region, and said holographic color filter spectroscopically splits said incident light so as to direct red light, green light, and blue light to said red display region, said green display region, and said blue display region, respectively.

### Claim 31 (depends on 1)

An optical pickup device for at least any of recording and reproducing of information on an optical information record medium, comprising: a light source for emitting a light beam; and a plurality of optical elements for controlling said light beam, wherein at least one of these optical elements includes the Si—O containing hydrogenated carbon film of claim 1, and this film includes a local region having a relatively high refractive index and a local region having a relatively low refractive index.

### Claim 32 (depends on 31)

The optical pickup device according to claim 31, wherein the optical element including the Si—O containing hydrogenated carbon film is any of a polarization beam splitter, a quarter wavelength plate, an objective lens, a focusing lens, and a collimator lens.

### Claim 33 (depends on 1)

An optical beam scan device comprising: a light source for emitting a light beam; an diffractive optical element for shaping said light beam; and light beam scan means for changing a traveling direction of said light beam, wherein said diffractive optical element includes the Si—O containing hydrogenated carbon film of claim 1 formed on a transparent substrate, and this film includes a plurality of regions having a relatively high refractive index and a plurality of regions having a relatively low refractive index.