Patents by Inventor Shoutarou KITAMURA

Shoutarou KITAMURA 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).

  • Patent number: 10020637
    Abstract: To improve characteristics of a semiconductor device (semiconductor laser), an active layer waveguide (AWG) comprised of InP is formed over an exposed part of a surface of a substrate having an off angle ranging from 0.5° to 1.0° in a [1-1-1] direction from a (100) plane to extend in the [0-1-1] direction. A cover layer comprised of p-type InP is formed over the AWG with a V/III ratio of 2000 or more. Thereby, it is possible to obtain excellent multiple quantum wells (MQWs) by reducing a film thickness variation of the AWG. Moreover, the cover layer having side faces where a (0-11) plane almost perpendicular to a substrate surface mainly appears can be formed. A sectional shape of a lamination part of the cover layer and the AWG becomes an approximately rectangular shape. Therefore, an electrification region can be enlarged and it is possible to reduce a resistance of the semiconductor device.
    Type: Grant
    Filed: June 1, 2017
    Date of Patent: July 10, 2018
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Satoshi Ae, Shoutarou Kitamura, Tetsuro Okuda, Suguru Kato, Isao Watanabe
  • Publication number: 20170271848
    Abstract: To improve characteristics of a semiconductor device (semiconductor laser), an active layer waveguide (AWG) comprised of InP is formed over an exposed part of a surface of a substrate having an off angle ranging from 0.5° to 1.0° in a [1-1-1] direction from a (100) plane to extend in the [0-1-1] direction. A cover layer comprised of p-type InP is formed over the AWG with a V/III ratio of 2000 or more. Thereby, it is possible to obtain excellent multiple quantum wells (MQWs) by reducing a film thickness variation of the AWG. Moreover, the cover layer having side faces where a (0-11) plane almost perpendicular to a substrate surface mainly appears can be formed. A sectional shape of a lamination part of the cover layer and the AWG becomes an approximately rectangular shape. Therefore, an electrification region can be enlarged and it is possible to reduce a resistance of the semiconductor device.
    Type: Application
    Filed: June 1, 2017
    Publication date: September 21, 2017
    Inventors: Satoshi AE, Shoutarou KITAMURA, Tetsuro OKUDA, Suguru KATO, Isao WATANABE
  • Patent number: 9698569
    Abstract: To improve characteristics of a semiconductor device (semiconductor laser), an active layer waveguide (AWG) comprised of InP is formed over an exposed part of a surface of a substrate having an off angle ranging from 0.5° to 1.0° in a [1-1-1] direction from a (100) plane to extend in the [0-1-1] direction. A cover layer comprised of p-type InP is formed over the AWG with a V/III ratio of 2000 or more. Thereby, it is possible to obtain excellent multiple quantum wells (MQWs) by reducing a film thickness variation of the AWG. Moreover, the cover layer having side faces where a (0-11) plane almost perpendicular to a substrate surface mainly appears can be formed. A sectional shape of a lamination part of the cover layer and the AWG becomes an approximately rectangular shape. Therefore, an electrification region can be enlarged and it is possible to reduce a resistance of the semiconductor device.
    Type: Grant
    Filed: September 19, 2014
    Date of Patent: July 4, 2017
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Satoshi Ae, Shoutarou Kitamura, Tetsuro Okuda, Suguru Kato, Isao Watanabe
  • Publication number: 20150085888
    Abstract: To improve characteristics of a semiconductor device (semiconductor laser), an active layer waveguide (AWG) comprised of InP is formed over an exposed part of a surface of a substrate having an off angle ranging from 0.5° to 1.0° in a [1-1-1] direction from a (100) plane to extend in the [0-1-1] direction. A cover layer comprised of p-type InP is formed over the AWG with a V/III ratio of 2000 or more. Thereby, it is possible to obtain excellent multiple quantum wells (MQWs) by reducing a film thickness variation of the AWG. Moreover, the cover layer having side faces where a (0-11) plane almost perpendicular to a substrate surface mainly appears can be formed. A sectional shape of a lamination part of the cover layer and the AWG becomes an approximately rectangular shape. Therefore, an electrification region can be enlarged and it is possible to reduce a resistance of the semiconductor device.
    Type: Application
    Filed: September 19, 2014
    Publication date: March 26, 2015
    Inventors: Satoshi AE, Shoutarou KITAMURA, Tetsuro OKUDA, Suguru KATO, Isao WATANABE