Integrated Zener diode for gate protection and voltage sourcing in integrated power management platforms

We describe a Zener diode integrated in a 0.18 micron based 60 V Power Management Process platform. By adding one ion implant layer, a buried diode with a sharp reverse breakdown current slope is implemented. A steep rise in reverse current, from 10^-8 A to 10^-3 A is obtained at the breakdown region, over less then 100 mV voltage variation. The buried interface has shown no breakdown voltage shifts under prolonged stress measurements at current densities exceeding 2 mA/um^λ2, shifts which were clearly observed in surface diodes. By varying the implant dose the reverse breakdown voltage-Vz, can be tuned from 4.5 V to 7.5 V. Consequently the diode is adequate for voltage sourcing applications and gate protection of the 5 V gates utilized by the LDMOS devices in the Power Management Process.