ION IMPLANTED ZENER DIODE

摘要

A method of making a zener diode having an accurately predetermined breakdown voltage. A discrete device and integrated circuit adaptation of this device is disclosed. A specially highly doped opposite conductivity type island is embedded in a high resistivity body portion. Embedded in the body portion contiguous the island is an ion implanted surface portion of the one conductivity type. The surface portion has an accurately predetermined concentration of conductivity determining impurity atoms in the range of about 1 x 1016 to 1 x 1019 atoms per cubic centimeter. A PN junction having a high breakdown voltage separates the island from the body. A PN junction having a lower but accurately predetermined breakdown voltage separates the island from the surface portion and forms a zener junction. In integrated circuit adaptations, this device preferably shares a transistor electrode for a transistor junction that is to be protected from overvoltage effects.