发明名称 |
Self-aligned mask formed utilizing differential oxidation rates of materials |
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.
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申请公布号 |
US6844225(B2) |
申请公布日期 |
2005.01.18 |
申请号 |
US20030345469 |
申请日期 |
2003.01.15 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
CHEN HUAJIE;SCHONENBERG KATHRYN T.;FREEMAN GREGORY G.;STRICKER ANDREAS D.;RIEH JAE-SUNG |
分类号 |
H01L21/321;H01L21/331;H01L29/732;H01L29/737;(IPC1-7):H01L21/00 |
主分类号 |
H01L21/321 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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