深亚微米工艺EEPROM单元加固设计及辐照性能

当普通EEPROM单元在太空中应用时,会受到辐照效应的影响,导致单元可靠性降低,寿命缩短,为此,基于0.18 μm工艺,设计出一种新型抗辐照EEPROM单元.新单元采用环形栅和场区隔离管加固结构.加固后,单元面积为9.56 μm2,抗总剂量效应能力大于1 500 Gy,抗辐照能力明显优于普通结构.为明确失效机制,基于新...

EEPROM cell hardness design and radiation characteristics in deep submicron process

The general EEPROM(electrically erasable programmable read-only memory) cell is affected by radiation effect when used in space,which leads to reduction of the cell’s reliability and life.Therefore,a new EEPROM cell is designed in 0.18 μm process,which uses annular gate and field oxide isolated transistor for radiation hardness.After reinforcement,the area of cell is 9.56 μm2,and the ability of total ionizing dose effect resistance is above 1 500 Gy.These characteristics of anti-radiation are better than those of the general cell.Based on the degeneration of threshold voltage in radiation condition,the radiation effects of cell are analyzed and compared with the general cell for determining the failure mechanism.The results show that the electricity leakages of source/drain in the parasitic edge transistor and under field oxide caused by the total ionizing dose effect are the main failure mechanisms of EEPROM in the deep submicron process.The radiation hardness designs against these failure mechanisms enhance the ability of anti-radiation and reliability of the cell.This work provides a good basis for meeting the need of memory in space application.