One time programming (OTP) with Zener diodes in CMOS processes

This article describes a lateral Zener diode in standard CMOS processes, without extra masks or technology steps, for one time programming (OTP) applications. The diode is adapted for programming (=zapping) requirements. The optimization of the device for low zapping currents and high yield is shown. The zapping process is evaluated in detail and follows an optimized layout and zapping conditions. The programming voltage is process dependent and lies between 6 V and 12 V, the zapping time is 1 /spl mu/s-4 /spl mu/s, and the required current is about 50 mA. The resistance of zapped diodes lies in the k/spl Omega/ range. The system needs only low voltage transistors, one extended drain medium voltage NMOS and one diode per bit. The selected diodes are introduced in several processes.