Radiation hardened read circuit with high reliability for SOI based SONOS memory

Abstract

A radiation hardened read circuit for a SONOS type EEPROM memory is designed in 0.6µm SOI process. Total dose radiation would cause large threshold voltage shifts of both memory cells and MOS transistors, hence degrades the reliability and performance of the sense amplifier. Compensation techniques for the sampling inverter and discharge path are proposed to achieve radiation hardness. Double branch precharge technique is developed to improve the read speed. As a result, the proposed sense amplifier is not sensitive to the radiation. Besides its high reliability, the proposed read circuit demonstrates high speed, achieving a sensing time of only 9.67ns.