发明申请
- 专利标题: Self-aligned mask formed utilizing differential oxidation rates of materials
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申请号: US10969718申请日: 2004-10-20
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公开(公告)号: US20050079726A1公开(公告)日: 2005-04-14
- 发明人: Huajie Chen , Kathryn Schonenberg , Gregory Freeman , Andreas Stricker , Jae-Sung Rieh
- 申请人: Huajie Chen , Kathryn Schonenberg , Gregory Freeman , Andreas Stricker , Jae-Sung Rieh
- 申请人地址: US NY Armonk
- 专利权人: International Business Machines Corporation
- 当前专利权人: International Business Machines Corporation
- 当前专利权人地址: US NY Armonk
- 主分类号: H01L21/321
- IPC分类号: H01L21/321 ; H01L21/331 ; H01L29/732 ; H01L29/737
摘要:
A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation. This self-aligned oxide mask blocks B diffusion from the raised extrinsic base to the corner of collector.