Patents Represented by Attorney, Agent or Law Firm Jeffrey L. Costelli
  • Patent number: 6316810
    Abstract: Concentration of metal element which promotes crystallization of silicon and which exists within a crystal silicon film obtained by utilizing the metal element is reduced. A first heat treatment for crystallization is implemented after introducing nickel element to an amorphous silicon film 103. Then, after obtaining the crystal silicon film, another heat treatment is implemented within an oxidizing atmosphere at a temperature higher than that of the previous heat treatment. At this time, HCl or the like is added to the atmosphere. A thermal oxide film 106 is formed in this step. At this time, gettering of the nickel element into the thermal oxide film 106 takes place. Next, the thermal oxide film 106 is removed. Thereby, a crystal silicon film 107 having low concentration of the metal element and a high crystalinity can be obtained.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: November 13, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Satoshi Teramoto, Jun Koyama, Yasushi Ogata, Masahiko Hayakawa, Mitsuaki Osame