发明名称 |
Bipolar transistor self-alignment with raised extrinsic base extension and methods of forming same |
摘要 |
A self-aligned bipolar transistor structure having a raised extrinsic base comprising an outer region and an inner region of different doping concentrations and methods of fabricating the transistor are disclosed. More specifically, the self-alignment of the extrinsic base to the emitter is accomplished by forming the extrinsic base in two regions. First, a first material of silicon or polysilicon having a first doping concentration is provided to form an outer extrinsic base region. Then a first opening is formed in the first material layer by lithography within which a dummy emitter pedestal is formed, which results in forming a trench between the sidewall of the first opening and the dummy pedestal. A second material of a second doping concentration is then provided inside the trench forming a distinct inner extrinsic base extension region to self-align the raised extrinsic base edge to the dummy pedestal edge. Since the emitter is formed where the dummy pedestal existed, the extrinsic base is also self-aligned to the emitter. The silicon or polysilicon forming the inner extrinsic base extension region can also be grown in the trench with selective or non-selective epitaxy.
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申请公布号 |
US6960820(B2) |
申请公布日期 |
2005.11.01 |
申请号 |
US20030604212 |
申请日期 |
2003.07.01 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
FREEMAN GREGORY G.;KHATER MARWAN H.;PAGETTE FRANCOIS |
分类号 |
H01L29/737;H01L21/331;H01L21/8222;H01L29/10;H01L29/732;(IPC1-7):H01L27/082;H01L27/102;H01L29/70;H01L31/11 |
主分类号 |
H01L29/737 |
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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