摘要 |
An improved Electrostatic Discharge (ESD) protection device for use in the electrostatic discharge testing of an integrated circuit (IC). In accordance with the invention, a p-n junction is formed beneath a polysilicon resistor, with a metal oxide layer separating the resistor and the p-n junction. The p-n junction is formed by positioning a semiconductor well having a first polarity between the metal oxide and a semiconductor substrate having a second polarity. The invention reduces the electrostatic potential across the metal oxide layer, which could otherwise result in damage to the metal oxide during ESD testing of the IC. In a preferred embodiment, the invention includes a switch, such as a transistor, between the well and ground, for allowing the well to float freely during normal circuit operation (to reduce noise) and for fixing the well at a fixed potential during ESD testing.
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