- 专利标题: High-purity yttrium, process of producing high-purity yttrium, high-purity yttrium sputtering target, metal gate film deposited with high-purity yttrium sputtering target, and semiconductor element and device equipped with the metal gate film
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申请号: US14130523申请日: 2011-09-15
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公开(公告)号: US10041155B2公开(公告)日: 2018-08-07
- 发明人: Masahiro Takahata
- 申请人: Masahiro Takahata
- 申请人地址: JP Tokyo
- 专利权人: JX Nippon Mining & Metals Corporation
- 当前专利权人: JX Nippon Mining & Metals Corporation
- 当前专利权人地址: JP Tokyo
- 代理机构: Howson & Howson LLP
- 优先权: JP2011-150067 20110706
- 国际申请: PCT/JP2011/071131 WO 20110915
- 国际公布: WO2013/005349 WO 20130110
- 主分类号: C22C28/00
- IPC分类号: C22C28/00 ; C22B59/00 ; C25C3/34 ; C23C14/34
摘要:
Provided are high-purity yttrium and a high-purity yttrium sputtering target each having a purity, excluding rare earth elements and gas components, of 5 N or more and containing 1 wt ppm or less of each of Al, Fe, and Cu; a method of producing high-purity yttrium by molten salt electrolysis of a raw material being a crude yttrium oxide having a purity, excluding gas components, of 4N or less at a bath temperature of 500° C. to 800° C. to obtain yttrium crystals, desalting treatment, water washing, and drying of the yttrium crystals, and then electron beam melting for removing volatile materials to achieve a purity, excluding rare earth elements and gas components, of 5N or more; and a technology capable of efficiently and stably providing high-purity yttrium, a sputtering target composed of the high-purity yttrium, and a metal-gate thin film mainly composed of the high-purity yttrium.