Patents by Inventor Yoshito Seiwa
Yoshito Seiwa 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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Patent number: 5547642Abstract: A light/ozone asher includes a process chamber having a sample stage for supporting a sample processed with active oxygen generated by irradiating ozone with UV rays while not irradiating the sample with UV rays. Since the sample is not irradiated with UV rays when an organic substance on the sample surface is removed, an organic substance (scum) left by removal of parts of the organic substance on the sample is removed without destroying the remaining pattern of organic substance.Type: GrantFiled: March 1, 1995Date of Patent: August 20, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshito Seiwa, Toshiaki Kitano, Yasutaka Kohno deceased
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Patent number: 5116769Abstract: A semiconductor laser device including a substrate containing a groove through which the laser light is emitted, a first layer disposed between the substrate and an active layer including a superlattice region opposite the groove and having the same conductivity type as the region in the sides walls of the groove and a disordered region in the first layer adjacent the superlattice of a different conductivity type from that of the superlattice region for confining current flow from the substrate to the active layer. A method of producing the semiconductor laser device includes implanting impurity ions which change the conductivity type but suppress the disordering of the superlattice region after annealing. The ions are implanted through the groove and produce the desired conductivity type region in the side walls of the groove.Type: GrantFiled: March 22, 1991Date of Patent: May 26, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yoshito Seiwa
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Patent number: 5034954Abstract: A semiconductor laser device including a substrate containing a groove through which the laser light is emitted, a first layer disposed between the substrate and an active layer including a superlattice region opposite the groove and having the same conductivity type as the region in the side walls of the groove and a disordered region in the first layer adjacent the superlattice of a different conductivity type from that of the superlattice region for confining current flow from the substrate to the active layer. A method of producing the semiconductor laser device includes implanting impurity ions which change the conductivity type but suppress the disordering of the superlattice region after annealing. The ions are implanted through the groove and produce the desired conductivity type region in the side walls of the groove.Type: GrantFiled: March 13, 1990Date of Patent: July 23, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yoshito Seiwa
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Patent number: 5010375Abstract: A semiconductor laser device include a Si substrate, a current confinement layer having an aperture disposed on the substrate, compound semiconductor layers disposed on the current confinement layer and on the Si substrate at the aperture of the current confinement layer, and a buffer layer for relieving the stress caused by the difference in lattice constants disposed between the Si substrate and the compound semiconductor layers. The Si substrate is of a first conductivity type and the current confinement layer is of a second conductivity type, or the current confinement layer comprises a compound semiconductor while the substrate comprises Si. The aperture of the current confinement layer is produced by anodic oxidation and selective etching of the current confinement layer. Therefore, a good re-growth interface at the substrate is obtained.Type: GrantFiled: May 17, 1989Date of Patent: April 23, 1991Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yoshito Seiwa
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Patent number: 4947401Abstract: A semiconductor laser array including multiple semiconductor layers serially disposed on each other to form a plurality of laser stripes that are laterally disposed within the layers each of the lasers stripes including a waveguide of a particular width wherein each of the waveguides has either a relatively wide width or a relatively narrow width and the stripes are laterally arranged with alternatingly wide and narrow waveguides.Type: GrantFiled: January 31, 1989Date of Patent: August 7, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Susumu Hinata, Yoshito Seiwa
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Patent number: 4924474Abstract: A laser device comprises a laser medium, a semiconductor light-emitting element for exciting the laser medium, a reflecting surface surrounding the outer periphery of the laser medium along its optical axis, and an opening provided in a part of the reflecting surface for causing light from the semiconductor light-emitting element to be incident upon the laser medium. The laser device is improved further by providing a polarizing plate and a light guide between the light-emitting element and the laser medium and by deviating the optical axis of excitation light from the central axis of the laser medium.Type: GrantFiled: February 10, 1989Date of Patent: May 8, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Shigenori Yagi, Yasuhito Myoi, Masaki Kuzumoto, Kazuki Kuba, Yoshito Seiwa, Toshitaka Aoyagi, Yutaka Mihashi
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Patent number: 4868837Abstract: A semiconductor laser includes an active region which includes a portion having a refractive index distribution with a relatively samll refractive index difference which allows only the fundamental mode of the transverse modes in the neighborhood of the light output facet. The other region of the active region has a refractive index distribution with a large refractive index difference which allows the fundamental mode as well as higher order modes.Type: GrantFiled: August 23, 1988Date of Patent: September 19, 1989Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshito Seiwa, Toshitaka Aoyagi
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Patent number: 4701926Abstract: A laser diode in accordance with the present invention comprises: a substrate (11) of p-GaAs; a current constricting layer (12) of n-GaAs formed with a slit (13) over the substrate, wherein the slit is opened through the constricting layer and separates the constricting layer into two areas; a liner(s) (21) of p-GaAs formed on at least both the inner side walls of the slit; a lower clad layer (14) of p-Ga.sub.0.6 Al.sub.0.4 As formed over the constricting layer, burying the slit; an active layer (15) of p-Ga.sub.0.9 Al.sub.0.1 As which is formed over the lower clad layer and has a refractive index higher than that of the lower clad layer; and an upper clad layer of n-Ga.sub.0.6 Al.sub.0.4 As which is formed over the active layer and has a refractive index lower than that of the active layer.Type: GrantFiled: March 6, 1986Date of Patent: October 20, 1987Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshito Seiwa, Saburo Takamiya