The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2019
Filed:
Apr. 23, 2008
Yasuhito Narushima, Omura, JP;
Shinichi Kawazoe, Omura, JP;
Fukuo Ogawa, Omura, JP;
Masahiro Irokawa, Omura, JP;
Toshimichi Kubota, Omura, JP;
Yasuhito Narushima, Omura, JP;
Shinichi Kawazoe, Omura, JP;
Fukuo Ogawa, Omura, JP;
Masahiro Irokawa, Omura, JP;
Toshimichi Kubota, Omura, JP;
SUMCO TECHXIV CORPORATION, Nagasaki, JP;
Abstract
The sublimation speed of dopant can be precisely controlled without being influenced by a change over time of intra-furnace thermal environment. A dopant supply unit equipped with an accommodation chamber and a supply tube is provided. A sublimable dopant is accommodated. Upon sublimation of the dopant within the accommodation chamber, the sublimed dopant is introduced into a melt. The dopant within the accommodation chamber of the dopant supply unit is heated. The amount of heating by means of heating means is controlled so as to sublime the dopant at a desired sublimation speed. The dopant is supplied to the melt so that the dopant concentration until the first half of a straight body portion of the silicon single crystal is in the state of low concentration or non-addition. After the first half of the straight body portion of the silicon single crystal is formed, the dopant is supplied to the melt so that every portion of the crystal is in the state where the dopant is added to a desired high concentration.