| 摘要 |
Methods and apparatus are provided for reducing substrate leakage current of lateral RESURF diode devices. The diode device ( 60, 60', 100 ) comprises first ( 39 ) and second ( 63 ) surface terminals overlying a semiconductor substrate ( 22 ) coupled to P ( 38, 32, 26 ) and N ( 24, 30, 46 ) type regions providing the diode action. An unavoidable parasitic vertical device ( 54, 92 ) permits leakage current to flow from the first terminal ( 39 ) to the substrate ( 22 ). This leakage current is reduced by having the diode device second terminal ( 63 ) comprise both N ( 46 ) and P ( 62 ) type regions coupled together by the second terminal ( 63 ). This forms a shorted base-collector lateral transistor ( 72 ) between the first ( 39 ) and second ( 63 ) terminals to provide the diode function. The gain of this lateral transistor ( 72 ) increases the proportion of first terminal ( 39 ) current that flows to the second terminal ( 63 ) rather than the substrate ( 22 ). In preferred embodiments, the first ( 39 ) or second ( 63 ) terminal is also ohmically coupled to a buried layer ( 24 ) that overlies the substrate ( 22 ) beneath the shorted base-collector lateral transistor ( 72 ).
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