Patents by Inventor Yoichi Iikubo

Yoichi Iikubo 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).

  • Publication number: 20090098709
    Abstract: To provide a method of manufacturing a semiconductor device, which prevents impurities from entering an SOI substrate. A source gas including one or plural kinds selected from a hydrogen gas, a helium gas, or halogen gas are excited to generate ions, and the ions are added to a bonding substrate to thereby form a fragile layer in the bonding substrate. Then, a region of the bonding substrate that is on and near the surface thereof, i.e., a region ranging from a shallower position than the fragile layer to the surface is removed by etching, polishing, or the like. Next, after attaching the bonding substrate to a base substrate, the bonding substrate is separated at the fragile layer to thereby form a semiconductor film over the base substrate. After forming the semiconductor film over the base substrate, a semiconductor element is formed using the semiconductor film.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 16, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Hideto OHNUMA, Yoichi IIKUBO, Shunpei YAMAZAKI
  • Publication number: 20090072343
    Abstract: A high-performance semiconductor device using an SOI substrate in which a low-heat-resistance substrate is used as a base substrate. Further, a high-performance semiconductor device formed without using chemical polishing. Further, an electronic device using the semiconductor device. An insulating layer over an insulating substrate, a bonding layer over the insulating layer, and a single-crystal semiconductor layer over the bonding layer are included, and the arithmetic-mean roughness of roughness in an upper surface of the single-crystal semiconductor layer is greater than or equal to 1 nm and less than or equal to 7 nm. Alternatively, the root-mean-square roughness of the roughness may be greater than or equal to 1 nm and less than or equal to 10 nm. Alternatively, a maximum difference in height of the roughness may be greater than or equal to 5 nm and less than or equal to 250 nm.
    Type: Application
    Filed: September 10, 2008
    Publication date: March 19, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Hideto OHNUMA, Yoichi IIKUBO, Yoshiaki YAMAMOTO, Kenichiro MAKINO, Akihisa SHIMOMURA, Eiji HIGA, Tatsuya MIZOI, Yoji NAGANO, Fumito ISAKA, Tetsuya KAKEHATA, Shunpei YAMAZAKI
  • Publication number: 20090004764
    Abstract: To provide a method for manufacturing an SOI substrate provided with a single-crystal semiconductor layer which is suitable for practical use even when a substrate of which heat-resistant temperature is low, such as a glass substrate, is used, and to manufacture a highly reliable semiconductor device using such an SOI substrate. A semiconductor layer, which is separated from a semiconductor substrate and bonded to a supporting substrate having an insulating surface, is heated by supplying high energy by using at least one kind of particles having the high energy, and polishing treatment is performed on the heated surface of the semiconductor layer. At least part of a region of the semiconductor layer can be melted by the heat treatment by supplying high energy to reduce crystal defects in the semiconductor layer. Further, the surface of the semiconductor layer can be polished and planarized by the polishing treatment.
    Type: Application
    Filed: June 20, 2008
    Publication date: January 1, 2009
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideto Ohnuma, Ryota Imahayashi, Yoichi Iikubo, Kenichiro Makino, Sho Nagamatsu
  • Publication number: 20080311726
    Abstract: There is provided a method of manufacturing an SOI substrate which is practicable even when a supporting substrate having a low allowable temperature limit is used. A separation layer is formed in a region at a certain depth from a surface of a semiconductor substrate, and a first heat treatment is conducted when a semiconductor layer on the separation layer is bonded to the supporting substrate and separated. A second heat treatment is conducted to the supporting substrate to which the semiconductor layer is bonded. The second heat treatment is conducted at a temperature which is equal to or higher than the temperature of the first heat treatment and does not exceed a strain point of the supporting substrate. When the first heat treatment and the second heat treatment are conducted at the same temperature, a treatment time of the second heat treatment may be set to be longer.
    Type: Application
    Filed: March 27, 2008
    Publication date: December 18, 2008
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideto Ohnuma, Yoichi Iikubo, Takayoshi SATO
  • Publication number: 20080246109
    Abstract: An SOI substrate having an SOI layer that can be used in practical applications even when a substrate with low upper temperature limit, such as a glass substrate, is used, is provided. A semiconductor device using such an SOI substrate, is provided. In bonding a single-crystal semiconductor layer to a substrate having an insulating surface or an insulating substrate, a silicon oxide film formed using organic silane as a material on one or both surfaces that are to form a bond is used. According to the present invention, a substrate with an upper temperature limit of 700° C. or lower, such as a glass substrate, can be used, and an SOI layer that is strongly bonded to the substrate can be obtained. In other words, a single-crystal semiconductor layer can be formed over a large-area substrate that is longer than one meter on each side.
    Type: Application
    Filed: March 10, 2008
    Publication date: October 9, 2008
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideto Ohnuma, Tetsuya Kakehata, Yoichi Iikubo