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What Is an Antenna Diode?

An antenna diode is a protection diode placed in a digital integrated circuit to guard transistor gates against damage during the chip fabrication process. It has nothing to do with radio antennas. The name comes from the “antenna effect,” a phenomenon that occurs during plasma etching.

The Antenna Effect

Modern ICs are built layer by layer. Metal interconnects and polysilicon wires are patterned using plasma etching, a process where ionized gas (plasma) selectively removes material. During this process, conductive structures like metal wires and polysilicon lines collect charge from the plasma.