发明授权
- 专利标题： Complementary zener triggered bipolar ESD protection
- 专利标题（中）： 互补齐纳触发双极ESD保护
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申请号： US11678962申请日： 2007-02-26
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公开(公告)号： US07701012B2公开(公告)日： 2010-04-20
- 发明人: Hongzhong Xu , Chai Ean Gill , James D. Whitfield , Jinman Yang
- 申请人： Hongzhong Xu , Chai Ean Gill , James D. Whitfield , Jinman Yang
- 申请人地址： US TX Austin
- 专利权人： Freescale Semiconductor, Inc.
- 当前专利权人： Freescale Semiconductor, Inc.
- 当前专利权人地址： US TX Austin
- 代理机构： Ingrassia, Fisher & Lorenz, P.C.
- 主分类号： H01L23/62
- IPC分类号： H01L23/62
摘要：
An electrostatic discharge (ESD) protection clamp (61) for I/O terminals (22, 23) of integrated circuits (ICs) (24) comprises an NPN bipolar transistor (25) coupled to an integrated Zener diode (30). Variations in the break-down current-voltage characteristics (311, 312, 313, 314) of multiple prior art ESD clamps (31) in different parts of the same IC chip is avoided by forming the anode (301) of the Zener (30) in the shape of a base-coupled P+ annular ring (75) surrounded by a spaced-apart N+ annular collector ring (70) for the cathode (302) of the Zener (30). Even though an angled implant (51, 86, 98) used to form the N+ annular collector ring (70) causes location dependent variations in the width (531, 532) of the Zener space charge (ZSC) region (691, 692), the improved annular shaped clamp (61) always has a portion that initiates break-down at the design voltage so that variations in the width (531, 532) of the ZSC region (691, 692) do not cause significant variations in the clamp's current-voltage characteristics (611, 612, 613, 614).
公开/授权文献
- US20080203534A1 COMPLEMENTARY ZENER TRIGGERED BIPOLAR ESD PROTECTION 公开/授权日：2008-08-28
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