Patents by Inventor Kikuo Makita
Kikuo Makita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20220416103Abstract: Reliability of a semiconductor device is improved. A solar battery includes: a solar battery element SB1 including an interface S1; a solar battery element SB2 including an interface S2 facing the interface S1; and a junction layer 120 being in contact with the interface S1 and the interface S2 and having light transmissivity. In this case, the junction layer 120 includes: a plurality of conductive nanoparticles 105 electrically connecting the solar battery element SB1 and the solar battery element SB2; and an adhesive material 116 filling gaps among the plurality of conductive nanoparticles 105. The interface S1 includes: a flat surface FT having concavity/convexity that is equal to or smaller than 2/3 times the minimum thickness of the junction layer 120; and a concave portion DIT having a depth that is equal to or larger than twice the minimum thickness of the junction layer 120 with respect to the flat surface FT.Type: ApplicationFiled: September 24, 2020Publication date: December 29, 2022Inventors: Kikuo MAKITA, Yukiko KAMIKAWA, Takeyoshi SUGAYA, Hidenori MIZUNO
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Patent number: 10608136Abstract: [Problem] The present invention provides a method for bonding semiconductor elements while assuring excellent electric conductivity and transparency at an interface, and a junction structure according to the bonding method. The present invention also provides a method for bonding semiconductor elements wherein excellent electric conductivity is assured at an interface and optical characteristics favorable for element characteristics can be designed, and a junction structure according to the bonding method. [Solution] Electrically conductive nano particles which are not covered with organic molecules are arrayed on a surface of one semiconductor element without causing optical loss, and another semiconductor element is pressure-bonded thereagainst.Type: GrantFiled: October 17, 2012Date of Patent: March 31, 2020Assignee: National Institute of Advanced Industrial Science and TechnologyInventors: Hidenori Mizuno, Kikuo Makita
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Publication number: 20140238485Abstract: [Problem] The present invention provides a method for bonding semiconductor elements while assuring excellent electric conductivity and transparency at an interface, and a junction structure according to the bonding method. The present invention also provides a method for bonding semiconductor elements wherein excellent electric conductivity is assured at an interface and optical characteristics favorable for element characteristics can be designed, and a junction structure according to the bonding method. [Solution] Electrically conductive nano particles which are not covered with organic molecules are arrayed on a surface of one semiconductor element without causing optical loss, and another semiconductor element is pressure-bonded thereagainst.Type: ApplicationFiled: October 17, 2012Publication date: August 28, 2014Inventors: Hidenori Mizuno, Kikuo Makita
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Patent number: 8148229Abstract: Disclosed is a method for manufacturing a semiconductor light-receiving device having high reproducibility and reliability. Specifically disclosed is a semiconductor light-receiving device 100 with a mesa structure wherein a light-absorbing layer 6, an avalanche multiplication layer 4 and an electric-field relaxation layer 5 are formed on a semiconductor substrate 2. The light-absorbing layer 6, avalanche multiplication layer 4 and electric-field relaxation layer 5 exposed in the side wall of the mesa structure are protected by an SiNx film or an SiOyNz film. The hydrogen concentration in the side wall surface of the electric-field relaxation layer 5 is set at not more than 15%, preferably not more than 10% of the carrier concentration of the electric-field relaxation layer 5.Type: GrantFiled: July 20, 2010Date of Patent: April 3, 2012Assignee: NEC CorporationInventors: Kazuhiro Shiba, Kikuo Makita, Takeshi Nakata
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Patent number: 7883911Abstract: A Schottky photodiode includes a semiconductor layer and a conductive film provided in contact with the semiconductor layer. The conductive film has an aperture and a periodic structure provided around said aperture for producing a resonant state by an excited surface plasmon in a film surface of the conductive film by means of the incident light to the film surface. The photodiode detects near-field light that is generated by at the interface between the conductive film and semiconductor layer the excited surface plasmon. The aperture has a diameter smaller than the wavelength of the incident light.Type: GrantFiled: March 11, 2009Date of Patent: February 8, 2011Assignee: NEC CorporationInventors: Keishi Oohashi, Tsutomu Ishi, Toshio Baba, Junichi Fujikata, Kikuo Makita
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Publication number: 20100279457Abstract: Disclosed is a method for manufacturing a semiconductor light-receiving device having high reproducibility and reliability. Specifically disclosed is a semiconductor light-receiving device 100 with a mesa structure wherein a light-absorbing layer 6, an avalanche multiplication layer 4 and an electric-field relaxation layer 5 are formed on a semiconductor substrate 2. The light-absorbing layer 6, avalanche multiplication layer 4 and electric-field relaxation layer 5 exposed in the side wall of the mesa structure are protected by an SiNx film or an SiOyNz film. The hydrogen concentration in the side wall surface of the electric-field relaxation layer 5 is set at not more than 15%, preferably not more than 10% of the carrier concentration of the electric-field relaxation layer 5.Type: ApplicationFiled: July 20, 2010Publication date: November 4, 2010Applicant: NEC CORPORATIONInventors: Kazuhiro SHIBA, Kikuo Makita, Takeshi Nakata
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Publication number: 20100200941Abstract: Intended is to provide a device structure, which makes the light receiving sensitivity and the high speediness of a photodiode compatible. Also provided is a Schottky barrier type photodiode having a conductive layer formed on the surface of a semiconductor layer. The photodiode is so constituted that a light can be incident on the back side of the semiconductor layer, and that a periodic structure, in which a light incident from the back side of the semiconductor layer causes a surface plasmon resonance, is made around the Schottky junction of the photodiode.Type: ApplicationFiled: November 28, 2007Publication date: August 12, 2010Inventors: Junichi Fujikata, Daisuke Okamoto, Kikuo Makita, Kenichi Nishi, Keishi Ohashi
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Patent number: 7728366Abstract: A Schottky photodiode includes a semiconductor layer and a conductive film provided in contact with the semiconductor layer. The conductive film has an aperture and a periodic structure provided around said aperture for producing a resonant state by an excited surface plasmon in a film surface of the conductive film by means of the incident light to the film surface. The photodiode detects near-field light that is generated by at the interface between the conductive film and semiconductor layer the excited surface plasmon. The aperture has a diameter smaller than the wavelength of the incident light.Type: GrantFiled: April 5, 2005Date of Patent: June 1, 2010Assignee: NEC CorporationInventors: Keishi Oohashi, Tsutomu Ishi, Toshio Baba, Junichi Fujikata, Kikuo Makita
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Patent number: 7560751Abstract: In a semiconductor photo-detecting element (an avalanche photodiode), a high-sensitivity element is obtained by incorporating a multiplication layer having high-performance multiplication characteristics. By using a structure which reduces an electric field applied to an etching stopper layer, it is possible to use a multiplication layer having higher-performance multiplication characteristics (a multiplication layer which performs multiplication with a high electric field). The first method to realize this is to use a conductivity type multiplication layer. The second method is to use a structure in which a field buffer layer of the second conductivity type is incorporated. As a result of the use of these methods, a structure which applies an electric field lower than the multiplier electrical field to the etching stopper layer is obtained.Type: GrantFiled: February 4, 2005Date of Patent: July 14, 2009Assignees: NEC Corporation, NEC Electronics CorporationInventors: Takeshi Nakata, Kikuo Makita, Atsushi Shono
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Publication number: 20090176327Abstract: A Schottky photodiode includes a semiconductor layer and a conductive film provided in contact with the semiconductor layer. The conductive film has an aperture and a periodic structure provided around said aperture for producing a resonant state by an excited surface plasmon in a film surface of the conductive film by means of the incident light to the film surface. The photodiode detects near-field light that is generated by at the interface between the conductive film and semiconductor layer the excited surface plasmon. The aperture has a diameter smaller than the wavelength of the incident light.Type: ApplicationFiled: March 11, 2009Publication date: July 9, 2009Inventors: Keishi Oohashi, Tsutomu Ishi, Toshio Baba, Junichi Fujikata, Kikuo Makita
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Publication number: 20090050933Abstract: Disclosed is a semiconductor light-receiving device having high reproducibility and reliability. Also disclosed is a method for manufacturing a semiconductor light-receiving device. Specifically disclosed is a semiconductor light-receiving device 100 with a mesa structure wherein a light-absorbing layer 6, an avalanche multiplication layer 4 and an electric-field relaxation layer 5 are formed on a semiconductor substrate 2. The light-absorbing layer 6, avalanche multiplication layer 4 and electric-field relaxation layer 5 exposed in the side wall of the mesa structure are protected by an SiNx film or an SiOyNz film. The hydrogen concentration in the side wall surface of the electric-field relaxation layer 5 is set at not more than 15%, preferably not more than 10% of the carrier concentration of the electric-field relaxation layer 5.Type: ApplicationFiled: December 15, 2005Publication date: February 26, 2009Applicant: NEC CorporationInventors: Kazuhiro Shiba, Kikuo Makita, Takeshi Nakata
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Patent number: 7488925Abstract: A light control apparatus includes a part for splitting an input light entering the light control apparatus through an optical fiber, a photoelectric conversion part for converting a monitor light into an electrical signal, and a third part for controlling the opening and closing of an optical transmission path for a signal light based on the electrical signal. The light power of an output light is controlled by the opening and closing amount of the optical transmission path which is controlled depending on the amount of the electrical signal output in accordance with the level of the monitor light. A semiconductor photovoltaic device capable of performing photoelectric conversion without using an external power source is used as the photoelectric conversion part. An optical shutter using a micromachine, or an optical device such as absorption-type modulator or refractive index-type modulator is used as the third part.Type: GrantFiled: November 17, 2004Date of Patent: February 10, 2009Assignee: NEC CorporationInventors: Kikuo Makita, Toshitaka Torikai
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Publication number: 20070194357Abstract: A Schottky photodiode includes a semiconductor layer and a conductive film provided in contact with the semiconductor layer. The conductive film has an aperture and a periodic structure provided around said aperture for producing a resonant state by an excited surface plasmon in a film surface of the conductive film by means of the incident light to the film surface. The photodiode detects near-field light that is generated by at the interface between the conductive film and semiconductor layer the excited surface plasmon. The aperture has a diameter smaller than the wavelength of the incident light.Type: ApplicationFiled: April 5, 2005Publication date: August 23, 2007Inventors: Keishi Oohashi, Tsutomu Ishi, Toshio Baba, Junichi Fujikata, Kikuo Makita
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Publication number: 20070090397Abstract: In a semiconductor photo-detecting element (an avalanche photodiode), a high-sensitivity element is obtained by incorporating a multiplication layer having high-performance multiplication characteristics. By using a structure which reduces an electric field applied to an etching stopper layer, it is possible to use a multiplication layer having higher-performance multiplication characteristics (a multiplication layer which performs multiplication with a high electric field). The first method to realize this is to use a conductivity type multiplication layer. The second method is to use a structure in which a field buffer layer of the second conductivity type is incorporated. As a result of the use of these methods, a structure which applies an electric field lower than the multiplier electrical field to the etching stopper layer is obtained.Type: ApplicationFiled: February 4, 2005Publication date: April 26, 2007Applicants: NEC CORPORATION, NEC ELECTRONICS CORPORATIONInventors: Takeshi Nakata, Kikuo Makita, Atsushi Shono
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Publication number: 20070086076Abstract: A light control apparatus includes a part for splitting an input light entering the light control apparatus through an optical fiber, a photoelectric conversion part for converting a monitor light into an electrical signal, and a third part for controlling the opening and closing of an optical transmission path for a signal light based on the electrical signal. The light power of an output light is controlled by the opening and closing amount of the optical transmission path which is controlled depending on the amount of the electrical signal output in accordance with the level of the monitor light. A semiconductor photovoltaic device capable of performing photoelectric conversion without using an external power source is used as the photoelectric conversion part. An optical shutter using a micromachine, or an optical device such as absorption-type modulator or refractive index-type modulator is used as the third part.Type: ApplicationFiled: November 17, 2004Publication date: April 19, 2007Applicant: NEC CORPORATIONInventors: Kikuo Makita, Toshitaka Torikai
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Patent number: 6165264Abstract: The invention provides a method for selective growth of semiconductor crystals, including the step of forming a semiconductor layer in a selected region of a semiconductor substrate by using a mask, the semiconductor layer being controlled with respect to atomic ordering or natural super lattice (NSL). It is possible by the invention to control the energy gap, optical anisotropy and electrically conductive anisotropy of a semiconductor layer, and also possible by the invention to carry out two-dimensional control of material properties in a substrate in accordance with a pattern of a mask.Type: GrantFiled: February 19, 1997Date of Patent: December 26, 2000Assignee: NEC CorporationInventors: Kikuo Makita, Akiko Gomyo
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Patent number: 5539221Abstract: An avalanche photodiode is provided which consists of a staircase APD with a periodic multilayer structure graded in composition from InAlAs to InGa.sub.x Al.sub.(1-x) As (x>0.1) as the multiplication layer to improve the dark current characteristic. Another photodiode with separate photoabsorption and multiplication regions is provided with an electric-field relaxation layer whose bandgap is wider than that of the photoabsorption and has a triple structure with a highly-doped layer sandwiched between lightly-doped layers. This photodiode incorporates in detail on an n-type InP substrate, an avalanche multiplication layer 13 of a periodic multilayer structure graded in composition from n.sup.- -InAlAs to InGa.sub.x Al.sub.(1-x) As, a p.sup.- -InGaAs photoabsorption layer 17, and an InP electric-field relaxation triple layer 16 consisting of n.sup.-, p.sup.+, and p.sup.- layers between the avalanche multiplication layer 13 and the photoabsorption layer 17.Type: GrantFiled: April 7, 1994Date of Patent: July 23, 1996Assignee: NEC CorporationInventors: Masayoshi Tsuji, Kikuo Makita
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Patent number: 5499259Abstract: A semiconductor optical device such as a light modulator or a tunable laser emitting diode has either light absorbing/transmitting layer, light modulation layer or tuning layer responsive to an electric field for changing the intensity or the wavelength of an output light, and the light absorbing/transmitting layer, the light modulation layer or the tuning layer is implemented by a super-lattice structure formed by using a first compound semiconductor material and a second compound semiconductor material, wherein the second compound semiconductor material is larger in electron affinity as well as the total of electron affinity and energy band gap than the first compound semiconductor material so that a large extinction ratio or a wide variation in wavelength is achieved.Type: GrantFiled: June 27, 1994Date of Patent: March 12, 1996Assignee: NEC CorporationInventor: Kikuo Makita
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Patent number: 5471068Abstract: On a p-type InP substrate 12, there are provided a p-type InGaAs light absorptive layer 14 and an InAlAs/InGaAs superlattice avalanche multiplier layer 15. By selecting the composition of the well layer and the barrier layer of the avalanche multiplier layer 15, a strain is applied to at least one of them so that the difference .DELTA. Ec between the energies at the lower end of the conduction band of the well layer and/or the barrier layer is increased, or the difference .DELTA. Ev between the energies at the upper end of the valence band of the well layer and/or the barrier layer is decreased, and/or the effective mass of the hole within the well layer and/or barrier layer is decreased. Thus, the ionization factor ratio is further improved, or the pile-up of the hole is alleviated, or the traveling time of the hole is shortened to achieve an avalanche multiplier semiconductor photodetector having a wide bandwidth, low noise and high response characteristic.Type: GrantFiled: February 28, 1994Date of Patent: November 28, 1995Assignee: NEC CorporationInventors: Masayoshi Tsuji, Kikuo Makita
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Patent number: 5204539Abstract: An avalanche photodiode includes an avalanche multiplication layer of a hetero-periodical structure consisting of alternately provided barrier and well layers. Each barrier layer includes a multi-quantum barrier layer consisting of alternately provided short-width barrier and well layers. The barrier and well layers include respectively first and second III-group elements which meet the following conditions:E.sub.A <E.sub.B, and E.sub.A +E.sub.gA <E.sub.B +E.sub.gBorE.sub.A <E.sub.B, and E.sub.A +E.sub.gA >E.sub.B +E.sub.gBwhere E.sub.A and E.sub.B are average ionization energies of the first and second III-group elements respectively, and E.sub.gA and E.sub.gB are forbidden band gap energies, respectively.Type: GrantFiled: January 27, 1992Date of Patent: April 20, 1993Assignee: NEC CorporationInventors: Masayoshi Tsuji, Kikuo Makita