发明授权
- 专利标题： Fabrication process of a semiconductor memory device having a multiple well structure in a recessed substrate
- 专利标题（中）： 在凹陷基板中具有多孔结构的半导体存储器件的制造工艺
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申请号： US355489申请日： 1994-12-14
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公开(公告)号： US5496758A公开(公告)日： 1996-03-05
- 发明人: Taiji Ema
- 申请人： Taiji Ema
- 申请人地址： JPX Kawasaki
- 专利权人： Fujitsu Limited
- 当前专利权人： Fujitsu Limited
- 当前专利权人地址： JPX Kawasaki
- 优先权： JPX6-031611 19940301
- 主分类号： H01L27/10
- IPC分类号： H01L27/10 ; H01L21/8242 ; H01L27/105 ; H01L27/108 ; H01L21/70 ; H01L27/00
摘要：
A method for fabricating a semiconductor memory device includes the steps of forming, in a semiconductor substrate of a first conductivity type, a well of a second opposite conductivity type by protecting the substrate surface except for a part where the well of the second conductivity type is to be formed, oxidizing the exposed surface of the semiconductor substrate while using the same mask pattern to form a thick oxide film on the surface of the well, and removing the thick oxide film by an etching process to form a recessed surface on the well.
公开/授权文献
- US4909241A Electric periodontal massager 公开/授权日：1990-03-20
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