发明名称 |
Semiconductor device comprising thin film transistor comprising conductive film having tapered edge |
摘要 |
There is provided a thin film transistor having improved reliability. A gate electrode includes a first gate electrode having a taper portion and a second gate electrode with a width narrower than the first gate electrode. A semiconductor layer is doped with phosphorus of a low concentration through the first gate electrode. In the semiconductor layer, two kinds of n<SUP>-</SUP>-type impurity regions are formed between a channel formation region and n<SUP>+</SUP>-type impurity regions. Some of the n<SUP>-</SUP>-type impurity regions overlap with a gate electrode, and the other n<SUP>-</SUP>-type impurity regions do not overlap with the gate electrode. Since the two kinds of n<SUP>-</SUP>-type impurity regions are formed, an off current can be reduced, and deterioration of characteristics can be suppressed.
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申请公布号 |
US7439543(B2) |
申请公布日期 |
2008.10.21 |
申请号 |
US20040013475 |
申请日期 |
2004.12.17 |
申请人 |
SEMICONDUCTOR ENERGY LABORATORY CO., LTD. |
发明人 |
YAMAZAKI SHUNPEI |
分类号 |
H01L29/76;H01L21/28;H01L21/336;H01L21/77;H01L21/84;H01L27/12;H01L29/423;H01L29/786 |
主分类号 |
H01L29/76 |
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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