发明授权
US6046095A Semiconductor substrate having polysilicon layers and fabrication
process of semiconductor device using the same
失效
具有多晶硅层的半导体衬底和使用其的半导体器件的制造工艺
- 专利标题： Semiconductor substrate having polysilicon layers and fabrication process of semiconductor device using the same
- 专利标题（中）： 具有多晶硅层的半导体衬底和使用其的半导体器件的制造工艺
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申请号： US340002申请日： 1999-06-25
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公开(公告)号： US6046095A公开(公告)日： 2000-04-04
- 发明人: Mitsuhiro Horikawa
- 申请人： Mitsuhiro Horikawa
- 申请人地址： JPX Tokyo
- 专利权人： NEC Corporation
- 当前专利权人： NEC Corporation
- 当前专利权人地址： JPX Tokyo
- 优先权： JPX8-029652 19960216
- 主分类号： H01L21/322
- IPC分类号： H01L21/322 ; H01C21/324
摘要：
On the back side of a base body, three layers of polysilicon layer are formed. These polysilicon layers contain boron. A boron concentration C.sub.B(1), C.sub.B(2) and C.sub.B(3) of the first, second and third polysilicon layers from the base body side have a relationship of C.sub.B(1) .ltoreq.C.sub.B(2) .ltoreq.C.sub.B(3). On the other hand, between the polysilicon layers, silicon oxide layers are formed respectively. Upon fabrication of a semiconductor device, at first, a gettering heat treatment is effected for the substrate under a given condition. Thus, contaminating impurity is captured at the grain boundary of polysilicon layers formed on the back side of the base body. Next, the polysilicon formed at the most back side is removed by etching. By this, contaminated impurity is removed from the semiconductor substrate.